Wireless transceiver and wireless communication system

Wireless transceiver and wireless communication system

WIRELESS TRANSCEIVER AND WIRELESS COMMUNICATION SYSTEM

The present invention relates to a wireless communication system for transmitting wireless signals between a plurality of wireless communication base stations and a wireless transceiver for use in the wireless communication system.

Previously, there have been various wireless transceivers which have various super heterodyne methods for converting a radio frequency into a relatively low frequency (intermediate frequency) and performing amplification and detection. For example, the wireless receiver disclosed in Patent Document 1 includes a local oscillation outputting a signal (that is, a local oscillation signal) of a frequency (local oscillation frequency) which is an integral multiple of the frequency of the input signal (reference oscillation signal). a mixer that mixes a received signal (Radio Freqency (RF) signal) received by an antenna with a local oscillating signal output from a local oscillator, thereby converting to a ratio A signal with a low frequency (intermediate frequency) of the RF signal (intermediate frequency signal). Moreover, various wireless transceivers using a phase locked loop (Phase Locked Loop) circuit as a local oscillator are also provided.

For the radio base station, the characteristics (RF characteristics) of the used radio waves, such as the occupied bandwidth or the adjacent channel leakage power, must satisfy the requirements of the radio wave method. For example, in the Japanese radio wave method, different specifications (communication specifications) are specified for each purpose of use. In particular, in the clause of Article 4 of the Japanese Radio Law, "small power wireless base station" is specified as one of the wireless base stations that do not require approval. "Small power wireless base station" has "radidless" a radio base station of a telephone, a "special low-power radio base station", a "small power security system", a "radio base station of a small power data communication system", etc., and a radio device of various radio base stations based on the radio wave The specification of the rules governs the rules of the equipment.

For example, a fire notification system disclosed in Patent Document 2 has been proposed as a wireless communication system including a specific low-power wireless base station. In the fire notification system, a plurality of fire alarms installed in a plurality of locations are provided as wireless base stations.

Each fire alarm includes a fire sensing unit that senses a fire, an alarm unit that emits an alarm sound, a wireless transmission unit that transmits a fire notification information for notifying a fire by a wireless signal, and a control alarm unit and a wireless transmission unit. The operation control unit of the operation (consisting of a micro-computer).

When the fire alarm unit detects the occurrence of a fire in any of the fire alarms, the arithmetic control unit of the fire alarm outputs an alarm sound from the alarm unit, and transmits the fire notification information to the other fire alarm from the wireless transmission unit. In other fire alarms, when the wireless transmission unit receives the fire notification information from the fire alarm of the fire source, an alarm sounds from the alarm unit. Therefore, when any fire alarm senses a fire, not only the fire alarm of the fire source but also the alarm sounds are outputted in succession from the plurality of fire alarms, so that the fire can be quickly and surely notified.

In this way, the fire alarm transmits the fire notification information by using the wireless signal to effectively exhibit the high degree of freedom in providing the position without wiring, and drives the battery as a power source. However, due to the fire sensor It is placed at a high place (such as a ceiling) that is difficult to maintain (replace the battery), so it is desirable to use it even if it is not maintained for several years, and it is required to reduce power consumption to extend battery life.

Therefore, in each of the fire alarms, the arithmetic control unit composed of the microcomputer is switched to the sleep state of the low power consumption, and the wireless transmission is performed, except that the alarm is issued during the fire detection and the fire notification information is wirelessly transmitted. The collection and reception of the receiving department stopped. However, if the arithmetic control unit is changed to the sleep state except for the fire detection, the fire notification information that is wirelessly transmitted from the other fire alarms cannot be received. Therefore, the arithmetic control unit that intermittently starts the sleep state in each of the fire alarms To perform wireless signal reception.

In other words, when the arithmetic control unit is activated by a start signal from a timer, it is checked whether or not a desired radio wave (fire notification information wirelessly transmitted from another fire alarm) can be received. Further, the reception check of the radio wave is performed by the arithmetic control unit causing the wireless transmission unit to perform the reception operation, and determining whether or not the received signal strength of the reception signal received by the wireless transmission unit exceeds a predetermined reference value. When the received signal strength does not exceed the reference value, the arithmetic control unit stops the transmission operation of the wireless transmission unit, sets the timer to the intermittent reception time until the next intermittent reception timing (timing), and starts counting ( After count), it changes to sleep state. On the other hand, when the received signal strength exceeds the reference value, the arithmetic control unit continues the reception state of the wireless transmission unit, analyzes the received signal received by the wireless transmission unit, and determines whether or not there is communication targeted for the local device. If there is communication targeting the unit, the corresponding processing is performed.

Therefore, the operation of the calculation control unit is intermittently performed, and when the reception control unit checks the reception state of the wireless transmission unit, if the desired radio wave cannot be received, the transmission operation of the wireless transmission unit is also stopped. Therefore, power consumption can be reduced to extend battery life.

On the other hand, as a conventional wireless communication device, there is a wireless communication device disclosed in Patent Document 1. This prior example is composed of an antenna 1000, an RF unit 1100, an interface unit 1200, and a microcomputer unit 1300, as shown in FIG. The RF unit 1100 includes a demodulation unit 111 that demodulates each received data (demodulated signal) from a radio signal received by the antenna 1000, and a sampling clock generation unit 112 that uses a sync bit sequence of the demodulated signal. Generate a sampling clock.

The interface 1200 includes: a frame code register 121, a memory frame synchronization unit (unique word), a frame synchronization offset register 122, and a demodulation unit. The demodulated received data is sequentially synchronized with the sampling clock; the frame synchronization detecting unit 123 outputs the frame synchronization when the frame register 121 matches the bit column of the frame synchronization offset register 122. The detection signal; and the receiving buffer (buffer) 124, when the frame synchronization detecting unit 123 detects the frame synchronization, synchronizes the sampling clock to memorize the received data.

The microcomputer unit 1300 includes a random access memory (RAM) 131 that memorizes received data, and a control unit 132 that decodes the original message from the received data stored in the RAM 131; The transmission unit 133 transmits the received data stored in the reception buffer 124 to the number of times designated by the control unit 132. The RAM 131 outputs a transmission end signal to the control unit 132 after the transfer is completed.

Next, the reception operation of the previous example will be described with reference to the time chart of FIG. Furthermore, the communication frame received in the previous example is a synchronization bit sequence (preamble) for obtaining bit synchronization, and a frame synchronization bit column for obtaining frame synchronization (unique Word), data indicating a communication message, and a check code for error detection (for example, Cyclic Redundancy Check (CRC)).

First, the microcomputer unit 1300 stands by in the sleep mode until the frame synchronization detecting unit 123 of the self-interface 1200 outputs the frame synchronization detecting signal. Then, when the wireless signal is received by the RF unit 1100 and the frame synchronization detecting unit 123 outputs the frame synchronization detecting signal from the frame synchronization detecting unit 123, the microcomputer unit 1300 starts the rising edge in synchronization with the rise of the frame synchronization detecting signal. Interrupt processing. The microcomputer unit 1300 that has started the rising edge interrupt processing is instructed by the control unit 132 to output the received data stored in the receiving buffer 124 to the interface portion 1200. In the microcomputer unit 1300, the transmission data output from the reception buffer 124 is transmitted to the RAM 131 by the transmission unit 133, and the control unit 132 decodes the original message. Then, when the control unit 132 receives a bit string of a predetermined length from the reception buffer 124, it outputs a reset signal to the RF unit 1100 and the dielectric surface 1200. In the RF unit 1100 and the interface 1200, when the reset signal is received from the control unit 132, the sampling clock generation unit 112 and the frame synchronization detecting unit 123 are reset.

In the above prior example, only the RF unit 1100 and the interface portion 1200 are normally operated, and the microcomputer portion 1300 is in the sleep mode, thereby reducing power consumption. The processing load of the microcomputer unit 1300 in the standby state is consumed or reduced, whereby there is an advantage that a low cost (low performance) microcomputer can be used.

However, even if the antenna 1000 does not receive the wireless signal, the demodulation unit 111 of the RF unit 1100 may output a signal composed of a random bit sequence due to the influence of thermal noise or radio noise. Further, in such a random bit string, the bit column having the same bit column (unique word) as the frame synchronization portion is included with a fixed probability , and thus the frame synchronization detecting portion 123 may erroneously detect The frame is synchronized and the frame synchronization detection signal is output. At this time, the microcomputer unit 1300 also starts the rising edge interruption processing in synchronization with the rise of the frame synchronization detection signal, and the control unit 132 instructs the interface portion 1200 to output the received data stored in the reception buffer 124. Further, in the microcomputer unit 1300, the transmission unit 133 transmits the received data output from the reception buffer 124 to the RAM 131, and the control unit 132 decodes the original message (see FIG. 17).

Further, the sampling clock generation unit 112 of the RF unit 1100 continuously monitors the bit row of the demodulated signal demodulated by the demodulation unit 111, since the bit width (pulse width) of the random bit column is not fixed. Therefore, it is immediately judged that the synchronization deviation is stopped and the sampling clock output is stopped. Once the output of the sampling clock is stopped, the frame synchronization detecting unit 123 also stops the output of the frame synchronization detecting signal. Then, in the microcomputer unit 1300, if the frame synchronization detection signal falls before the bit string of the predetermined length is received from the receiving buffer 124, the falling edge interrupt processing is started and the data received from the receiving buffer 124 is discarded ( The bit row) is output to the standby state after the RF unit 1100 and the dielectric surface 1200 output a reset signal (see FIG. 17).

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-28331

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2008-176515

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2006-237931

However, among the above two kinds of local oscillators, the local oscillator using the frequency multiplying circuit has an advantage of less power consumption than the local oscillator using the PLL circuit. On the other hand, in the former local oscillator, there is an advantage that the variable range of the frequency is wider than the local oscillator of the latter. In a general wireless transceiver, a local oscillator using a PLL circuit is often used in consideration of a wide variable range of frequencies. On the other hand, when a PLL circuit is used, power consumption is increased as compared with the case of using a frequency multiplying circuit. In particular, in a wireless transceiver mounted in a device that uses a battery as a power source, a local oscillator (a local oscillator using a frequency multiplying circuit) having a small power consumption is used, and a battery can be extended in life. advantage.

In the fire notification system of Patent Document 2, the calculation control unit intermittently operates to reduce the power consumption. However, the calculation control unit activated by the timer checks the reception state of the wireless transmission unit to determine whether or not it is possible. The desired radio wave is received together with the measurement result of the received signal strength. When the desired radio wave cannot be received, the arithmetic control unit causes the wireless transmission unit to stop the transmission operation and then shifts its own operation state to the sleep state. However, the wireless transmission unit measures the received signal strength. The arithmetic control unit continues to operate. Therefore, there is the problem that during this period, The arithmetic control unit generates invalid power consumption, and accordingly, the battery life is shortened.

Further, in Patent Document 3 described above, if a regular wireless signal is received after a erroneous synchronization occurs due to the influence of thermal noise or radio noise, the wireless signal may not be received normally. The case where such a phenomenon occurs will be described with reference to the timing chart of Fig. 18 . Furthermore, N in FIG. 18 is a random value obtained by demodulating thermal noise, P is a preamble, U is a unique word, and 1, 2, 3... are data.

When the erroneous detection occurs at the time t=t1 and the frame synchronization detection signal rises, the microcomputer unit 1300 starts the rising edge interruption processing, but then immediately inputs the regular wireless signal. Since the pulse width of the bit row of the demodulated signal is scattered when the normal radio signal is input (time t=t9), the sampling clock generation unit 112 determines that the synchronization is excessive. At this time, before the control unit 132 outputs a control signal (time t=t3) indicating that the interface surface 1200 outputs the reception data stored in the reception buffer 124 (time t=t2), the synchronization may be delayed. The frame sync detection signal drops. Since the control signal is output from the microcomputer unit 1300 after the falling of the frame synchronization detection signal, the frame synchronization detection signal is degraded, and the output is output from the reception buffer 124 to the microcomputer unit 1300 in synchronization with the falling of the control signal. Receive data (time t=t4).

At the same time, the microcomputer unit 1300 ends the processing of the rising edge interrupt processing, and therefore detects the falling of the frame synchronization detection signal, starts the falling edge interrupt processing, and discards the stored received data (time t=t6).

Then, starting from the point of time when the synchronization deviates (time t=t2), The frame synchronization detecting unit 123 detects the unique word from the demodulated signal of the normal wireless signal and the frame synchronization detection signal rises (time t=t5), and the microcomputer unit 1300 performs the falling edge interruption at this point (time t=t5). deal with. When the falling edge interrupt processing ends (time t=t6), the microcomputer unit 1300 detects the rise of the frame synchronization detecting signal and starts the rising edge interrupt processing, and the control unit 132 outputs the instruction medium 1200 to output the memory in the receiving buffer 124. The control signal of the received data (time t=t8) starts the storage of the received data from time t=t8. However, the received data is continuously outputted from the output indication for the erroneous synchronization (time t=t4).

As a result, when the control signal is output from the microcomputer unit 1300 (time t=t8), the received data of the regular wireless signal is output from the reception buffer 124, so even if the microcomputer unit 1300 falls from the control signal (time t) =t7) When the data is received, there is also a situation in which it is impossible to receive the output of the first 3-digit data. Moreover, even if the microcomputer unit 1300 discards the content of the received data, the instruction interface 1200 discards the content of the receiving buffer 124 and starts storing the control signal of the received data after the next frame synchronization detection, but it is frame synchronization. After the rise of the detection signal (time t=t5), a situation in which the received data is not stored in the reception buffer 124 occurs.

The present invention has been made in view of the above circumstances, and provides a wireless transceiver which can achieve both a reduction in power consumption in a local oscillator and a variable range of frequencies.

The present invention provides a method for further reducing power consumption of the above wireless base station Wireless communication system.

The present invention provides a wireless communication system that can correctly receive a regular wireless signal immediately after a false synchronization.

A wireless transceiver according to a first aspect of the present invention includes: a local oscillator that oscillates at a predetermined local oscillation frequency; and a mixer that outputs a local oscillation signal of the local oscillation frequency from an output end of the local oscillator And a wireless signal received by the antenna; a modulation circuit that modulates the local oscillation signal to generate a wireless signal; and a transmission switching unit that selectively connects the output of the local oscillator to The receivable state of the mixer is switched between a transmittable state in which the output terminal is connected to the antenna side without the mixer, and the local oscillator includes a reference oscillator that is lower than the local oscillation frequency. The predetermined reference oscillation frequency oscillates; the first frequency conversion unit and the second frequency conversion unit convert the reference oscillation signal of the reference oscillation frequency output from the output end of the reference oscillation unit into the local oscillation signal; the first switching unit Selectively connecting the output end of the reference oscillation unit to the first input state of the input end of the first frequency conversion unit And switching the output end of the reference oscillation unit to the second input state of the input end of the second frequency conversion unit; and the second switching unit interlocking the switching operation of the first switching unit to selectively The output end of the local oscillator is connected to the first output state of the output end of the first frequency conversion unit, and the second output state in which the output end of the local oscillator is connected to the output end of the second frequency conversion unit is switched. 2 frequency conversion section has a voltage controlled oscillator, a phase comparator, a frequency divider, and a loop filter And a phase synchronization loop circuit of a charge pump, wherein the first frequency conversion unit is configured by a frequency multiplying circuit having less power consumption than the phase synchronization loop circuit.

According to this configuration, it is possible to achieve a reduction in power consumption in the local oscillator and a variable range of the frequency.

In a wireless communication system according to a second aspect of the present invention, a wireless signal based on a radio wave is transmitted between a plurality of wireless base stations, wherein each of the wireless base stations includes a wireless transmission unit that receives a wireless signal, and a radio wave level measuring unit. Measuring the received signal strength of the wireless signal received by the wireless transmitting unit; the timer outputs an activation signal every time the predetermined intermittent receiving time is counted; and the arithmetic control unit receives the received signal from the wireless transmitting unit The analysis is performed to acquire the information for the local device, and the wireless transmission unit has a function of receiving a wireless signal from the main ground according to the setting of the operation command by the calculation control unit, and the radio wave level measurement unit includes the calculation control unit. The setting of the operation command is a function of performing an operation of measuring the received signal strength of the wireless signal received by the wireless transmission unit from the main ground, and when the arithmetic control unit is activated by the activation signal from the timer in the sleep state, The wireless transmission unit and the radio wave level measuring unit set the operation command and shift to the sleep state until the radio wave When the measurement result of the received signal intensity is equal to or greater than a predetermined reference value, the radio frequency measuring unit continues the receiving operation, and the arithmetic control unit performs the receiving signal on the received signal. In the analysis, if the measurement result is smaller than the reference value, the wireless transmission unit stops the reception operation.

According to this, by further reducing the power consumption of the arithmetic control unit, A wireless communication system that further reduces the power consumption of a wireless base station.

A wireless communication system according to a third aspect of the present invention includes: a wireless transmission unit that performs signal processing on a wireless signal received by an antenna and converts it into a bit string of a pulse wave signal; and an arithmetic control unit that transmits the wireless signal from the wireless transmission The bit column outputted by the receiving unit acquires information included in the wireless signal, and the communication frame of the wireless signal includes a synchronization bit column for obtaining bit synchronization, and a frame synchronization bit for obtaining frame synchronization. And the data and the data corresponding to the information, the wireless transmission unit includes: a demodulation unit that demodulates the wireless signal into a demodulated signal composed of a bit line of the pulse wave signal; and the frame synchronization detecting unit The bit sequence of the demodulated signal detects the frame synchronization bit column and outputs a frame synchronization detection signal; and the receiving data buffer temporarily stores the output from the demodulation unit when the frame synchronization detection signal is output a demodulation signal; and a command processing unit that outputs the received data stored in the received data buffer to the received data output command outputted from the arithmetic control unit The calculation control unit includes: an interface that transmits and receives a signal to and from the wireless transmission unit; and a central processing unit that acquires the wireless signal from the bit line output from the wireless transmission unit Processing for outputting information or outputting the received data output command to the wireless transmission unit when the frame synchronization detection signal is output, the command processing unit starts the message from the frame synchronization detecting unit When the output of the frame synchronization detection signal is not received until the output of the frame synchronization detection signal is stopped, the frame synchronization detection unit outputs the next frame synchronization detection signal until the frame synchronization detection unit starts. From the above calculation control The central processing unit of the system outputs the received data output command, and does not output the received data stored in the received data buffer.

According to this configuration, there is an effect that the regular wireless signal can be correctly received immediately after the erroneous synchronization.

The object and features of the present invention will become apparent from the following description of the preferred embodiments.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings which are a part of this specification. In all the drawings, the same or similar components are denoted by the same reference numerals, and the repeated description thereof will be omitted.

(Embodiment 1)

Hereinafter, embodiments of the present invention will be described in detail with reference to Figs. 1 to 5 . Fig. 1 shows a wireless communication system to which a wireless transceiver according to an embodiment of the present invention is applied.

As shown in FIG. 2, the wireless transceiver according to the first embodiment includes a local oscillator 1, an antenna 2, an RF filter 3, a low noise amplifier 4, a mixer 5, and an intermediate frequency (Intermediate Frequency). The filter 6, the intermediate frequency amplifier (IF amplifier) 7, the demodulation unit 8, the transmission unit 9, the antenna switching unit 10, the transmission switching unit 11, and the control unit 12 (corresponding to the arithmetic control unit of Fig. 1). Here, in the wireless transceiver of the present embodiment, as the modulation method, for example, frequency modulation (frequency shift keying: FSK) is employed. In the (frequency shift keying) method, the radio signal transmitted from the antenna 2 is changed by a signal corresponding to the frequency division ratio m of the programmable frequency divider 32 to be described later. The variable processing performs demodulation on the radio signal received by the antenna 2 by the post demodulator 8 that converts it into an intermediate frequency lower than the frequency (radio frequency) of the radio signal. However, the method of the modulation processing is not limited to the above-described modulation processing. For example, the transmission unit 9 may mix the signal (local oscillation signal) output from the local oscillator 1 with the modulation signal, or may be a method. In order to correspond to the modulation signal, a switched capacitor or a varactor (varicap) to be described later is provided. A method in which the capacitance of the variable capacitance portion configured by diode or the like is changed. Further, the modulation method is not limited to the frequency modulation method, and may be, for example, a phase modulation (phase shift keying) method such as BPSK.

The local oscillator 1 includes a reference oscillation unit 20, a multiplication unit 21, a PLL unit 22, a first switching unit 23, and a second switching unit 24. The reference oscillation unit 20 oscillates at a predetermined reference oscillation frequency fx lower than the radio frequency, and outputs a reference oscillation signal. The reference oscillation unit 20 includes a variable capacitance unit (not shown) including a switching capacitor or a varactor diode (not shown), and the control unit 12 changes the capacitance of the variable capacitance unit. The reference oscillation frequency fx is selected from a plurality of frequencies fx1, fx2, fx3, . The multiplication unit 21 corresponds to the first frequency conversion unit, and converts the reference oscillation signal output from the reference oscillation unit 20 into a signal (local oscillation signal) of the local oscillation frequency fy. The PLL unit 22 corresponds to the second frequency conversion unit, and converts the reference oscillation signal output from the reference oscillation unit 20 into a local oscillation frequency. Local oscillation signal of fy. The first switching unit 23 is selectively switched to a first input state in which the output end of the reference oscillation unit 20 is connected to the input end of the multiplication unit 21, and a second input state in which the output end of the reference oscillation unit 20 is connected to the input end of the PLL unit 22. Enter the status. The second switching unit 24 selectively switches the first output state in which the output terminal of the local oscillator 1 is connected to the output terminal of the multiplying unit 21 and the second output in which the output terminal of the local oscillator 1 is connected to the output terminal of the PLL unit 22. status.

The multiplication unit 21 outputs a signal (that is, a local portion) of a frequency (local oscillation frequency fy) of an integer multiple of the frequency fx of the input signal (reference oscillation signal) by nonlinearity of an input/output characteristic such as a transistor (for example). A frequency multiplying circuit of an oscillating signal). However, since such a multiplication unit 21 is a well-known person, the detailed configuration and operation will be omitted. Further, as the multiplying section 21, a previously known Deley Locked Loop circuit can also be used.

The PLL unit 22 is a well-known person, and includes a voltage controlled oscillator (Voltage Controlled Oscillator) 30, a 1/n frequency divider 31, a programmable frequency divider 32, a phase comparator 33, a loop filter 34, and a charge pump 35. The 1/n frequency divider 31 divides the reference oscillation signal to 1/n (n is a positive integer). Moreover, the programmable frequency divider 32 divides the output signal of the voltage controlled oscillator 30 by one in m (m is a positive integer or fraction different from n). The phase comparator 33 detects the phase difference between the two frequency dividers 31, 32, and outputs a signal corresponding to the phase difference. The charge pump 35 charges and discharges the electric charge based on the signal output from the phase comparator 33. The loop filter 34 smoothes the signal output according to the charge and discharge of the charge pump 35. And by The voltage controlled oscillator 30 is controlled by the DC signal output from the loop filter 34, thereby outputting a local oscillation signal of the local oscillation frequency fy (= m / n × fx) from the PLL section 22. Here, the frequency division numbers n and m of the two frequency dividers 31 and 32 can be set to an arbitrary integer value by the control unit 12 (where m can also be a fraction), and the frequency division numbers n and m are set to appropriate. The integer value (where m can also be a fraction) can change the local oscillation frequency fy of the local oscillator 1.

Here, when the multiplication unit 21 having the above configuration is compared with the PLL unit 22, the power consumption of the multiplication unit 21 is smaller than that of the PLL unit 22, and the variable range of the local oscillation frequency fy of the PLL unit 22 is wider than that of the multiplication unit 21.

Further, in the voltage controlled oscillator 30 of the PLL unit 22, an operating power supply is supplied from an external power supply (system power supply) Vcc, and a power supply for turning on/off the power supply from the system power supply Vcc to the voltage controlled oscillator 30 is provided. Switch SW1. That is, when the switch SW1 is turned off by the control unit 12, the power supply terminal is disconnected from the system power supply Vcc and the voltage controlled oscillator 30 is stopped. When the switch SW1 is turned on, the power supply terminal is connected to the system power supply Vcc and the voltage controlled oscillator. 30 action. Here, a bypass capacitor C1 that electrically connects the power supply terminal to the power supply terminal of the voltage control oscillator 30 is connected to stabilize the power supply voltage.

The first switching unit 23 selectively switches the common terminal 23c connected to the output end of the reference oscillation unit 20 to the switching terminal 23a connected to the input terminal of the multiplication unit 21 and the input terminal connected to the PLL unit 22 (1/n points). The switching terminal 23b of the input terminal of the frequency converter 31). Moreover, the second switching unit 24 The common terminal 24c connected to the common terminal 11c of the transmission switching unit 11 is selectively switched to the switching terminal 24a connected to the output terminal of the multiplication unit 21 and the output terminal (voltage controlled oscillator 30) connected to the PLL unit 22. The switching terminal 24b of the output terminal). Further, the transmission switching unit 11 selectively switches the common terminal 11c to the switching terminal 11a connected to the input terminal of the mixer 5 and the switching terminal 11b connected to the input terminal of the transmitting unit 9. At substantially the same time, the antenna switching unit 10 selectively switches the common terminal 10c connected to the antenna 2 to the switching terminal 10a connected to the input terminal of the RF filter 3 and the switching terminal connected to the output terminal of the transmitting unit 9. 10b. Further, the antenna switching unit 10, the transmission switching unit 11, the first switching unit, and the second switching units 23 and 24 are all controlled by the control unit 12. The switching control of the control unit 12 switches the first switching unit 23 and the second switching unit 24 substantially simultaneously, and switches the antenna switching unit 10 and the transmission switching unit 11 substantially simultaneously. However, from the viewpoint of preventing an unexpected malfunction, it is preferable to switch the first switching unit 23, the second switching unit 24, the antenna switching unit 10, and the transmission switching unit 11 substantially simultaneously, or After the first switching unit 23 and the second switching unit 24 are switched and controlled substantially simultaneously, the antenna switching unit 10 and the transmission switching unit 11 are switched at substantially the same time.

The transmitting unit 9 is configured by an amplifier that amplifies the modulated wireless signal (RF signal) output from the local oscillator 1, and amplifies the wireless signal (RF signal) output from the local oscillator 1 and outputs it to the antenna switching unit 10. . Further, the wireless signal input via the antenna switching unit 10 is radiated from the antenna 2 as a radio wave. In addition, since the transmission unit 9 is well known in the prior art, the detailed configuration and operation will be omitted.

Here, the local oscillator 1 selects and outputs a local oscillation signal of a local oscillation frequency (a frequency equal to a difference between the radio frequency and the intermediate frequency) that is lower than a radio frequency of the radio signal, and a transmission equal to a radio frequency. Local oscillation signal of the local oscillation frequency. Further, in the wireless transceiver of the present embodiment, the local oscillation signal having a relatively high frequency selected for the reception local oscillation signal and the transmission local oscillation signal is converted and output to the first frequency conversion unit (multiplication unit 21). The local oscillation signal having the relatively low frequency described above is converted and outputted to the second frequency conversion unit (PLL unit 22). For example, when the frequency of the received wireless signal (including the standby operation for receiving the wireless signal, the same applies hereinafter) is higher than the frequency of transmitting the wireless signal, the local oscillation signal for reception is converted and output to the multiplication unit. 21, thereby achieving lower power consumption than when converting the output to the PLL section 22. On the other hand, when the frequency of transmitting the wireless signal is higher than the frequency of receiving the wireless signal, the local oscillation signal for transmission is converted and outputted to the multiplication section 21, thereby achieving a lower ratio than when the conversion is output to the PLL section 22. power consumption. However, the conditions for using the multiplication unit 21 and the PLL unit 22 in a different manner are not limited to the reception time and the transmission time. For example, as will be described later, when a plurality of channels can be selected as the radio frequency, if the channel of the default (initial state) is selected, the multiplier 21 is used as the frequency converting portion of the local oscillator 1, On the other hand, when the PLL unit 22 is used as the frequency conversion unit of the local oscillator 1 when the preset channel is selected, the power consumption can be reduced in the same manner.

The wireless transceiver of this embodiment is used, for example, in FIG. 5 for a certain wireless communication device Xi (j is a natural number). Some kind of wireless communication machine Xj has light Various environmental measurement sensors Sk (k is a natural number unrelated to j) in the sensor S1, the thermal sensor S2, the chemical sensor S3, the pressure sensor S4, ..., etc. At least one of them. Further, the wireless communication device Xj senses a change in the surrounding environment of the installation place while being mounted on a ceiling surface or a wall surface, and transmits a wireless signal to the other wireless communication device Xj to notify when the change in the surrounding environment is sensed. Here, the types of the environmental measurement sensors Sk may be uniform or different for each wireless communication device Xj. For example, the wireless communication device X1 alone activates the wireless receiver of the device (the wireless transceiver of this embodiment) at a fixed intermittent receiving interval, and cannot receive it from other wireless communication devices X2, X3, X4, .. The wireless communication device X1 immediately stops the wireless transceiver of the local device to prevent battery consumption. On the other hand, if the first wireless signal Sig1 can be received, it not only indicates the fact that the first wireless signal Sig1 has been received, but also transmits from the wireless transceiver of the local (wireless communication device X1) that the above-mentioned first A wireless signal Sig1 is transmitted to the second wireless signal Sig2 of the other unspecified plurality of wireless communication machines X2, X3, X4, . As illustrated in FIG. 5, any one of the wireless communication devices Xj is provided with at least one of a display notification portion X100 that is visually perceived by a person or a sound notification portion X101 that is audibly heard by a person, when any wireless communication is performed. When the device Xj (the wireless communication device X1 in FIG. 5) senses an abnormality in the surroundings, the wireless communication device Xj itself causes the display notification portion X100 or the sound notification portion X101 to operate, thereby notifying the surrounding that an abnormality has occurred, and transmitting the first A wireless signal Sig1. And, all other wireless communication devices that have received the first wireless signal Sig1 (figure Only the wireless communication device X2 closest to the wireless communication device X1 receives the first wireless signal Sig1 and performs address analysis, and transmits the second wireless signal Sig2 to the first wireless signal that is not received. Other wireless communication devices of Sig1 (X3, X4 other than wireless communication devices X1 and X2 in Fig. 5). Since the wireless communication device X3 cannot grasp whether the second wireless signal Sig2 from the wireless communication device X2 has been received by the wireless communication device X4, then, the wireless communication device X3 that has received the second wireless signal Sig2 will be the second type. The wireless signal Sig2 is transmitted to the wireless communication machine X4. As a result, not only the one (the wireless communication device X1) that has initially detected the abnormality, but also the wireless communication devices (the wireless communication devices X1, X2, X3, and X4) registered in advance can notify the surrounding of the abnormality.

More specifically, the operation of the wireless transceiver of the present embodiment will be described in association with the operation of the wireless communication device.

First, when none of the wireless communication devices senses the environmental change around the installation place, the control unit 12 counts the intermittent reception interval by a timer (not shown), and the counting of the intermittent reception interval is completed. When the wireless transceiver is activated in an acceptable state. In other words, when the counting of the intermittent receiving interval is completed, the control unit 12 switches the common terminal 10c of the antenna switching unit 10 to the switching terminal 10a on the RF filter 3 side, and switches the common terminal 11c of the transmission switching unit 11 to the connection. The switching terminal 11a to the side of the mixer 5. Further, the control unit 12 switches the common terminal 23c of the first switching unit 23 to the switching terminal 23a connected to the input terminal of the multiplication unit 21, and switches the common terminal 24c of the second switching unit 24 to the multiplication unit 21. The switching terminal 24a of the output terminal. At this time, the control department The switch SW1 is turned off, and the power supply terminal of the voltage controlled oscillator 30 is disconnected from the system power supply Vcc to stop the PLL unit 22.

In this receivable state, the IF amplifier 7 amplifies the intermediate frequency signal (IF signal), and at the same time, outputs an RSSI (Received Signal Strength Display) signal indicating the signal strength of the input signal (the IF signal before amplification) to Control unit 12. When the RSSI signal is smaller than the predetermined threshold, the control unit 12 determines that the radio wave received by the antenna 2 is not a desired wave (a radio wave transmitted from another wireless communication device), and immediately stops the wireless transceiver. On the other hand, when the RSSI signal is equal to or greater than the threshold value, the control unit 12 determines that the received radio wave is highly likely to be a desired wave, and causes the radio transceiver to continue operation and demodulation by the demodulation unit 8.

When the wireless signal demodulated by the demodulation unit 8 is the first wireless signal transmitted from another wireless communication device, the control unit 12 switches the common terminal 10c of the antenna switching unit 10 to the switching terminal 10b on the transmitting unit 9 side. The common terminal 11c of the transmission switching unit 11 is switched and connected to the switching terminal 11b on the transmitting unit 9 side. Further, the control unit 12 switches the common terminal 23c of the first switching unit 23 to the switching terminal 23b connected to the input terminal of the PLL unit 22, and switches the common terminal 24c of the second switching unit 24 to the PLL unit 22. The switching terminal 24b of the output terminal. Further, the control unit 12 turns on the switch SW1 and connects the power supply terminal of the voltage controlled oscillator 30 to the system power supply Vcc to operate the PLL unit 22.

Then, the control unit 12 encodes a transmission frame including a signal indicating that the first wireless signal for transmission to another wireless communication device is transmitted, and the PLL unit 22 of the local oscillator 1 uses the above-mentioned frame. The local oscillation signal force is modulated to generate a signal for wireless transmission, and is amplified by the transmission unit 9 and then output to the antenna 2 via the antenna switching unit 10. As a result, the second wireless signal described above is transmitted from the antenna 2.

When the wireless communication device performs intermittent reception, the first frequency conversion unit (multiplication unit 21) operates as the frequency conversion unit of the local oscillator 1, whereby power consumption can be reduced. On the other hand, when the wireless communication device transmits the first or second wireless signal, as described above, the second frequency converting portion (PLL portion 22) is selected as the frequency converting portion of the local oscillator 1, and Since the variable circuit operates, it is possible to cover a frequency (radio frequency) that the multiplication unit 21 cannot correspond to. As a result, the power consumption in the local oscillator 1 can be reduced, and the variable range of the frequency can be ensured. In other words, in the wireless communication system, if the frequency of operation of the wireless transceiver of each wireless communication device Xj in the receivable state is compared with the frequency of operation in the transmittable state, it is considered to be receivable. Since the frequency of the operation is overwhelmingly high, as described above, the power consumption can be reduced by selecting the multiplication unit 21 in an receivable state. On the other hand, by selecting the PLL unit 22 in the transmittable state, the selection range (variable range) of the local oscillation frequency can be secured, and transmission can be performed at a desired radio frequency.

As described above, it is preferable that the frequency (radio frequency) of the radio wave used by the wireless communication device can be appropriately selected from a plurality of radio frequencies (channels) depending on the environment of the installation place. In order to change the channel, the local oscillation frequency fy of the local oscillator 1 must be changed according to the channel. As described above, the PLL unit 22 can easily change the local oscillation frequency fy by adjusting the frequency division numbers j and k, but adjusts the multiplication number of the multiplication unit 21 to change the local oscillation frequency. The rate fy is not easier than adjusting the frequency division numbers j and k of the PLL unit 22.

Therefore, in the reference oscillation unit 20 of the present embodiment, a variable capacitance unit (not shown) including a switching capacitor or a varactor diode or the like is provided, and the control unit 12 changes the capacity of the variable capacitance unit. By selecting the reference oscillation frequency fx of the reference oscillation unit 20 from the plurality of frequencies fx1, fx2, fx3, ..., the local oscillation frequency fy can be easily changed while the multiplication number of the multiplication unit 21 is fixed. Therefore, even when the channel of the radio frequency can be changed, the multiplying unit 21 can be used as the frequency converting unit of the local oscillator 1 in the receivable state, and since the PLL unit 22 is not used in the receivable state, Therefore, the power consumption of the wireless transceiver (local oscillator 1) can be reduced.

However, as described above, when the wireless transceiver is activated every other intermittent reception interval to perform intermittent reception, if the power supply to the local oscillator 1 is uniformly turned on/off, the charging current flows through each time. The voltage of the PLL unit 22 controls the bypass capacitor C1 connected to the power supply terminal of the oscillator 30, thereby consuming invalid power. However, in the present embodiment, the connection between the bypass capacitor C1 and the system power supply Vcc is opened and closed by the opening and closing unit (switch SW1), and the control unit 12 is used only when the PLL unit 22 is used as the frequency conversion unit of the local oscillator 1. The switch SW1 is closed (turned on). Therefore, it is possible to prevent the bypass capacitor C1 from being charged and discharged when the PLL unit 22 is not required, and to consume invalid power.

Further, as shown in FIG. 3(a), another switch SW2 may be added between the power supply terminal of the voltage controlled oscillator 30 and the bypass capacitor C1, so that the two switches SW1 and SW2 and the voltage controlled oscillator are provided. 30 electric The source terminal is turned on and off in conjunction with the switch SW1 between the system power supply Vcc.

Moreover, when the switch SW1 (or the switch SW2) is closed and the bypass capacitor C1 is connected to the system power supply Vcc, an inrush current (charging current) flows, thereby causing the voltage of the system power supply Vcc to temporarily drop. Therefore, ideally, as shown in FIG. 3(b), a current limiting resistor R is connected between the bypass capacitor C1 and the system power supply Vcc, and the inrush current is limited by the current limiting resistor R to reduce the system power supply. The phenomenon that the voltage of Vcc temporarily drops.

However, in the normal period after the inrush current flows, the reactive current is consumed by the current limiting resistor R, and the voltage applied to the power supply voltage of the voltage controlled oscillator 30 is lowered, so that it is preferable. As shown in FIGS. 4(a) and 4(b), a short-circuit portion (switch SW3) for short-circuiting the system power supply Vcc and the power supply terminal of the voltage controlled oscillator 30 is provided. At this time, the control unit 12 closes the inrush current by the current limiting resistor R by closing the switch SW1 while opening the switch SW3 (refer to FIG. 4(a)), and closes the switch SW3 and opens it. The switch SW1 thereby cuts off the current limiting resistor R on the circuit (see FIG. 4(b)). As a result, by not passing a normal current through the current limiting resistor R, inefficient power consumption and voltage drop can be avoided. However, the switch SW1 can also remain closed.

However, the condition for switching the frequency conversion unit in the local oscillator 1 from the multiplication unit 21 to the PLL unit 22 is not limited to the above-described reception time and transmission time. As described above, the multiplication section 21 generates a local oscillation signal by using nonlinearity or by multiplying the reference oscillation frequency by an integral multiple by a delay demultiplexed loop circuit. Therefore, the output from the PLL unit 22 In addition to the local oscillation signal, the local oscillation signal output from the multiplication unit 21 includes a plurality of unnecessary frequency components of an integral multiple of the reference oscillation frequency in addition to the desired local oscillation frequency. Therefore, when the multiplication unit 21 is used as the frequency conversion unit of the local oscillator 1, it is highly likely that radio waves (obstructive waves) having different frequencies from the radio waves (wireless signals) originally intended to be received are received, and there is a possibility of being affected by the obstruction waves. The disadvantage (specifically, it is susceptible to the influence of the interference wave including the integer component of the reference oscillation frequency ± the frequency component of the intermediate frequency). On the other hand, since the PLL unit 22 has a relatively small number of unnecessary frequency components included in the oscillation frequency after frequency conversion, it has an advantage that it is less likely to be affected by the interference wave than the multiplication unit 21. However, when a battery is used as a power source as in the above-described wireless communication device, when a PLL circuit is used as the frequency conversion portion of the local oscillator, the battery life is shortened compared to when the multiplier circuit is used.

Therefore, when the reception signal (IF signal) output from the mixer 5 is not normally demodulated by the demodulation unit 8, the control unit 12 switches the first switching unit 23 to the second input state and will be the second. The switching unit 24 may be switched to the second output state. Specifically, when the bit spectrum of the received signal (IF signal) cannot be acquired by the demodulation unit 8 even though the RSSI signal is equal to or greater than the threshold value, it is considered that the reception cannot be normally received due to the influence of the interference wave. In the wireless signal, the control unit 12 performs switching control of the first switching unit and the second switching units 23 and 24 to switch the frequency conversion unit in the local oscillator 1 from the multiplication unit 21 to the PLL unit 22. In this way, it is possible to achieve a long life of the battery and it is difficult to be affected by the wave.

Here, if the multiplication unit 21 is switched to the PLL unit 22 during reception, The time until the circuit operation of the PLL unit 22 is stabilized cannot be normally received. On the other hand, when the intensity of the interference wave in the use environment of the wireless transceiver (the setting environment of the wireless communication device) is high, the frequency conversion unit of the local oscillator 1 is frequently switched from the multiplication unit 21 to the PLL unit 22, However, if the intensity of the interference wave in the use environment is low, the multiplication unit 21 can be normally received even if the frequency conversion unit of the local oscillator 1 is used.

Therefore, the control unit 12 is only required to switch between the first switching unit and the second switching unit 23 and 24 in a predetermined period from the start of the use of the wireless transceiver (the point at which the wireless communication device group starts the operation of the wireless communication system). After the predetermined period of time has elapsed, the state of the first switching unit and the second switching units 23 and 24 may be fixed to a state at the elapse of a predetermined period. Further, after the control unit 12 switches from the multiplying unit 21 to the PLL unit 22 during the receiving process, after a fixed time (for example, several hours), the control unit 12 switches from the PLL unit 22 to the multiplying unit 21 and confirms whether or not it is receivable, and if it is receivable, The multiplication section 21 is used. In this case, the control unit 12 may switch the first switching unit 23 to the second input state and switch the second switching unit 24 to the second output state by a predetermined number of times, and then start the first time at the start of the intermittent reception. The switching unit 23 switches to the second input state and switches the second switching unit 24 to the second output state. As described above, when it is used in an environment where the influence of the wave is small, the multiplication portion 21 can be used only for the frequency conversion portion of the local oscillator 1 to extend the life of the battery. On the other hand, when it is used in an environment where the influence of the interference wave is large, the PLL unit 22 can be used only for the frequency conversion unit of the local oscillator 1 to receive the wireless signal normally and quickly.

However, it is considered that the influence of the obstacle wave in the daytime is larger than that at night. because In addition, the control unit 12 may be provided with a clock for counting the time, and the control unit 12 switches the first switching unit 23 to the second input state and the second switching unit when the time counted by the clock is the daytime period. 24 switches to the second output state, and switches the first switching unit 23 to the first input state and switches the second switching unit 24 to the first output state when the time is the night time. As described above, when it is used in a period (night) in which the influence of the wave is small, the multiplication portion 21 can be used only for the frequency conversion portion of the local oscillator 1 to extend the life of the battery. On the other hand, when it is used in a period (daytime) in which the influence of the wave is large, the PLL unit 22 can be used only for the frequency converting portion of the local oscillator 1 to receive the wireless signal normally and promptly.

Further, the reference oscillating unit 20 is configured to selectively switch a plurality of types of reference oscillating signals that output different reference oscillating frequencies fx1, fx2, ..., and to make the first frequency converting unit different from each other by a multiplication number. The multiplication circuits 1 to i (i2) are constructed. Further, when the first switching unit 23 is switched to the first input state and the second switching unit 24 is switched to the first output state, and the reception signal is not normally demodulated, the control unit 12 may not change the local oscillation frequency. Fy and sequentially change the combination of the reference oscillation frequency fxi (i = 1, 2, ...) of the reference oscillation signal and the multiplication number of the multiplication circuit.

For example, when the local oscillation frequency fy is to be 420 MHz, the reference oscillation frequency fx1 = 52.5 MHz and the reference oscillation frequency fx2 = 70 MHz may be used in combination. In the former case, it is susceptible to an interference wave of an integer multiple of 52.5 MHz ± intermediate frequency, whereas in the latter case, it is susceptible to an interference wave of an integer multiple of 70 MHz ± intermediate frequency. That is, since the frequencies of the susceptible wave that are susceptible are different from each other, Therefore, it is possible to select a combination of the reference oscillation frequency and the multiplication number which are hard to be affected by the interference wave frequency existing at this time, so as to alleviate the influence of the interference wave.

By changing the combination of the reference oscillation frequency fxi of the reference oscillation signal and the multiplication number of the multiplication circuit without changing the local oscillation frequency fy as described above, the reception signal may be normally received. However, when the received signal is not normally demodulated in all combinations, the control unit 12 switches the first switching unit 23 to the second input state and switches the second switching unit 24 to the second output state to select the PLL unit. 22 can be.

Next, a wireless alarm system (fire alarm system) that uses a fire alarm that emits an alarm sound and transmits a radio signal (including fire notification information) based on a radio wave as a wireless base station, with reference to FIG. 6 to FIG. Embodiments to which the technical idea of the present invention is applied will be described.

(Embodiment 2)

Fig. 6 is a view showing a configuration of a wireless communication system to which the second embodiment is applied. Corresponding to the simplified illustration of Fig. 1, a plurality of (only two are shown) fire alarms TR constitute a fire alarm system. In the following description, each of the fire alarms will be described as fire alarms TR1, TR2, ..., TRn (n is a positive integer), and when all the fire alarms are described, Fire alarm TR.

The fire alarm unit TR includes a calculation control unit 100, a wireless transmission unit 200, a radio wave level measuring unit 300, a timer 400, a fire sensing unit 500, an alarm unit 600, and a battery power supply unit 700 as main components.

The wireless transmission unit 200 transmits a wireless signal that is radio-mediated from the antenna 2a, and receives no transmission from other fire alarms TR by the antenna 2a. Line signal. The wireless transmission unit 200 has a function of autonomously performing a predetermined operation, that is, an operation of receiving a wireless signal when the operation command is set by the arithmetic control unit 100. In addition, the wireless transmission unit 200 can use, for example, the "radio base station of the small power safety system" specified in the sixth wave of the Japanese Radio Law.

The radio wave level measuring unit 300 measures the received signal strength of the radio signal received by the radio transmission unit 200. The radio wave level measuring unit 300 has a function of autonomously performing a predetermined operation, that is, an operation of measuring a received signal strength of a wireless signal when the operation command is set by the arithmetic control unit 100.

Here, the timer 400 repeats the counting operation of the time interval of the intermittent receiving operation described later (this time interval is referred to as the intermittent receiving time), and outputs an activation signal to the arithmetic control unit 100 every time the counting operation is completed.

When the fire sensor 500 detects a fire such as smoke, heat, flame, or the like generated by the fire, the fire control unit 100 activates the sleep control unit 100 and outputs the fire detection signal to the calculation control unit 100. In addition, the detailed configuration of the fire sensing unit 500 is well known in the prior art, and thus detailed description thereof will be omitted.

The alarm unit 600 outputs a fire alarm (hereinafter referred to as "alarm sound") composed of a sound (a buzzer sound or a voice message) from a speaker (not shown) to the surrounding person. Inform the fire.

The battery power supply unit 700 uses a battery such as a dry battery as a power source, and supplies an operating power supply to each unit.

The arithmetic control unit 100 includes a microcomputer (not shown) or a memory unit 100a (consisting of a rewritable non-volatile semiconductor memory) as a main constituent element. The arithmetic control unit 100 executes a memory (Read-only memory (ROM) or Electrically Erasable Programmable Read Only Memory (EEPROM) (not shown) by using a microcomputer. The program stored in (etc.), etc., thereby implementing various functions to be described later. Further, when the local machine does not detect the fire or the intermittent reception operation of the timer control by the timer 400, the calculation control unit 100 stops the transmission operation of the wireless transmission unit 200 to save power. And turn its own action state into a sleep state with low power consumption.

When the operation state of the arithmetic control unit 100 is switched to the sleep state, when the fire sensing unit 500 senses a fire, the fire sensing unit 500 outputs an activation signal to the arithmetic control unit 100 to activate the arithmetic control unit 100. The arithmetic control unit 100 that is activated from the sleep state causes the buzzer provided in the alarm unit 600 to sound, for example, based on the fire detection signal input from the fire sensing unit 500, thereby performing the notification operation. Further, instead of the buzzer sound, a sound message (for example, "fire has occurred" or the like) stored in advance in the memory (or the memory unit 100a) may be output from the speaker, thereby performing the notification operation. Further, in order to perform the notification operation in conjunction with the other fire alarms TR, the arithmetic control unit 100 transmits a wireless signal including the fire notification information for notifying the occurrence of the fire from the wireless transmission unit 200. In the other fire alarm TR, the wireless transmission unit 200 receives the wireless signal including the fire notification information, whereby the arithmetic control unit 100 receives the fire contained in the wireless signal. When the information is notified, the arithmetic control unit 100 controls the alarm unit 600 and performs a notification operation. Further, a unique identifier is assigned to each of the fire alarms TRn and stored in the memory unit 100a, and the identifier of the wireless signal and the fire alarm TRn of the transmission source (fire source) can be specified using the identifier.

Here, the calculation control unit 100 is configured by, for example, a micro controller that is designed to be low-power consumption for battery driving, and such a microcontroller includes, for example, MSP430 (registered trademark) of Texas Instruments. Further, a specific-purpose integrated circuit for communication in which a wireless transmission unit of a specific low-power radio base station or an intermittent reception function by a timer function is integrated into a single chip (one chip) is provided. Application Specific Integrated Circuit (ASIC). As such an ASIC, for example, ML7066 of OKI Semiconductor Co., Ltd., or the like, such a ASIC is used to constitute the wireless transmission unit 200, the radio wave level measuring unit 300, or the timer 400.

The calculation control unit 100 can obtain power from the battery power supply unit 700, and reduces power consumption in order to extend battery life. That is, the operation state of the arithmetic control unit 100 is switched to the sleep state except for the fire perception, and the wireless transmission unit 200 also stops the transmission operation. Further, the arithmetic control unit 100 is activated every time a predetermined intermittent receiving time elapses, and can also receive wireless signals transmitted from other fire alarms TR, and check (intermittent reception) whether or not the desired electric wave can be received (other fire alarms TR) The wireless signal sent). When the desired radio wave is captured during the intermittent reception, the arithmetic control unit 100 causes the wireless transmission unit 200 to continue the reception operation and analyzes the signal received by the wireless transmission unit 200. On the other hand, if When the desired radio wave is not captured during the reception, the arithmetic control unit 100 immediately stops the reception operation of the wireless transmission unit 200 and shifts to the standby state. In addition, the radio wave reception check is performed by the radio wave level measurement unit 300 based on the received signal strength indication signal (Resivation Signal Strength Indication: RSSI signal) output from the radio transmission unit 200. Here, the received signal strength signal (RSSI signal) refers to a DC voltage signal that is proportional to the magnitude of the received signal strength.

However, for example, in the wireless device of the wireless base station of the small power safety system of Article 49 of the Radio Regulations of the Japanese Radio Law, the transmission of the radio wave is completed within 3 seconds after the radio wave is transmitted, and must pass 2 Can be sent after seconds (refer to the same article No. 5). In other words, it is determined that the transmission period of the radio wave is set to within 3 seconds, and the suspension period of 2 seconds or more after the transmission is set, and the fire alarm TR ends the transmission in the transmission period in accordance with the wireless device rule. The transmission is stopped during the subsequent rest period and switched to the receivable state. Here, the time interval of the above-described intermittent receiving operation, that is, the intermittent receiving time, is set to be longer than the transmission period (within 3 seconds) specified in the wireless device rule.

Here, the above-described intermittent receiving operation will be described in detail with reference to the flowchart of Fig. 7 . The arithmetic control unit 100 sets an intermittent reception time to the timer 400 before transitioning to the sleep state, and after the start of the counting operation (step S1), the operation is shifted to the sleep state (step S2). When the timer 400 completes the counting operation of the intermittent receiving time (count up) (Yes in step S3), the timer 400 outputs an activation signal to the arithmetic control unit 100 to cause the arithmetic control unit 100 to self-sleep. Start up (step S4). Boot from the sleep state After the operation command is set in each of the wireless transmission unit 200 and the radio wave level measurement unit 300 (step S5), the calculation control unit 100 shifts to the sleep state until the measurement operation of the radio wave level measurement unit 300 is completed (step S6).

When the operation command is set by the arithmetic control unit 100, the wireless transmission unit 200 autonomously performs a receiving operation (step S7). When the operation command unit 300 sets the operation command, the radio wave level measurement unit 300 autonomously performs an operation of measuring the received signal strength of the signal received by the wireless transmission unit 200 (step S8). When the measurement operation is completed, the radio wave level measuring unit 300 outputs an activation signal to the arithmetic and control unit 100, and causes the arithmetic and control unit 100 to start from the sleep state (step S9). The calculation control unit 100, which is activated from the sleep state, introduces the measurement result of the received signal strength from the radio wave level measuring unit 300, and compares the measurement result of the received signal strength with the predetermined reference value (step S10). Here, the reference value is set to be higher than the received signal strength in a state where the wireless signal is not transmitted from the other fire alarm TR, and is higher than the received signal strength in a state in which the wireless signal is transmitted from the other fire alarm TR. Low value.

When the measurement result of the received signal strength is equal to or greater than the reference value (Yes in step S10), the arithmetic control unit 100 determines that the wireless signal is transmitted from the other fire alarm TR, and causes the wireless transmission unit 200 to continue the reception operation (step S11). The received signal is analyzed (step S12). When the result of the analysis of the received signal is that the received signal includes the fire notification information, the arithmetic control unit 100 causes the alarm unit 600 to perform the above-described alarm operation based on the fire notification information, and interlocks with the fire alarm TR of the fire source. The notification operation (step S13).

On the other hand, if the measurement result of the received signal strength is smaller than the reference value (NO in step S10), the arithmetic control unit 100 determines that the wireless signal is not transmitted from the other fire alarm TR, and causes the wireless transmission unit 200 to The receiving operation is stopped (step S14). Subsequently, the arithmetic control unit 100 returns to the operation of step S1, sets an intermittent reception time to the timer 400, starts the counting operation, and shifts to the sleep state until the counting of the timer 400 is completed (step S2).

As described above, when the activation control unit 100 receives the activation signal from the timer 400 and starts the operation, the arithmetic control unit 100 sets the operation command to the wireless transmission unit 200 and the radio wave level measurement unit 300, and then shifts to the sleep state. Therefore, when the wireless transmission unit 200 performs the receiving operation and the radio wave level measuring unit 300 measures the received signal strength, the arithmetic control unit 100 is switched to the sleep state, so that the power consumption of the arithmetic control unit 100 can be further reduced. Therefore, when the wireless base station (fire alarm TR) is battery-driven, the battery life can be extended, and the period of battery replacement can be extended, so that the burden of maintenance work can be reduced. Further, the wireless transmission unit 200 and the radio wave level measurement unit 300 operate autonomously when the operation command is set by the calculation control unit 100, and when the received signal strength is equal to or greater than the reference value, the wireless transmission unit 200 continues the reception operation. The wireless signal transmitted from other wireless base stations (fire alarm TR) can be surely received.

In the present embodiment, when the radio wave level measuring unit 300 completes the measurement of the received signal strength during the intermittent reception, the radio wave level measuring unit 300 activates the arithmetic control unit 100 from the sleep state, and the arithmetic control unit 100 receives the signal according to the reception signal. The measurement result of the intensity is used to judge the presence or absence of the received signal. therefore, In the intermittent reception, after the operation command is set in the wireless transmission unit 200 and the radio wave level measurement unit 300, the calculation control unit 100 is in the sleep state until the measurement of the received signal strength is completed, so that the calculation in this period can be reduced. The power consumption of the control unit 100. Further, the arithmetic control unit 100 compares the received signal strength measured by the radio wave level measuring unit 300 with the reference value. When the measurement result of the received signal strength is equal to or greater than the reference value, the arithmetic control unit 100 continues the reception operation of the wireless transmission unit 200 and analyzes the received signal, so that it can surely receive the TR from another fire alarm. Wireless signal. Further, when the received signal strength is smaller than the reference value, the arithmetic and control unit 100 stops the reception operation of the wireless transmission unit 200, so that the power consumption of the wireless transmission unit 200 can be reduced.

Further, in the wireless communication system including the plurality of fire alarms TR, the designated fire alarm TR1 (hereinafter referred to as the primary base station) checks whether the other fire sensors TR2 to TRn (hereinafter referred to as sub-base stations) are normal. Regular monitoring of actions. That is, in the fire alarm TR1 of the master base station, the arithmetic control unit 100 activates the wireless transmission unit 200 periodically (for example, every 24 hours), and transmits a wireless signal including the periodic monitoring information to the child base station. In each of the sub-base stations TR2 to TRn, the arithmetic control unit 100 monitors the presence or absence of a failure of the fire sensing unit 500 or the remaining amount of the battery power supply unit 700 at a fixed cycle (for example, every one hour), and monitors the result (with or without a failure). And whether the remaining power is reduced or not) is memorized in the memory portion 100a. Then, when the autonomous base station TR1 receives the periodic monitoring message, the arithmetic control unit 100 of each of the sub-base stations TR2 to TRn returns a fire notification message including the monitoring result stored in the memory unit 100a to the main base station TR1. Wireless signal. The arithmetic control unit 100 of the main base station TR1 switches the radio transmission unit 200 to the reception state after receiving the radio signal including the fire notification information, and receives the radio signals transmitted from the sub-base stations TR2 to TRn. Further, if there is a sub-base station TR2 that has not returned the fire notification information within a predetermined time after transmitting the periodic monitoring message, the arithmetic control unit 100 of the main base station TR1 controls the alarm unit 600 and notifies the sub-base station TR2... Abnormal (cannot communicate). Further, when any of the sub-base stations TR2... returns the fire notification information for notifying that the failure has occurred or the remaining battery power is reduced, the arithmetic control unit 100 of the main base station TR1 also controls the alarm unit 600 and notifies the sub-base station TR2. Abnormality of ... (failure, loss of remaining battery power, etc.). Further, when the failure of the fire detecting unit 500 or the decrease in the remaining battery power is detected, the arithmetic unit 100 of the master base station TR1 and the child base station TR2... immediately drives the alarm unit 600 of the own unit and notifies that the abnormality has occurred.

Further, the arithmetic control unit 100 of the primary base station TR1 transmits a wireless signal including the fire notification information from the wireless transmission unit 200 after the fire detection, or receives a wireless signal including the fire notification information from any of the sub-base stations TR2. Thereafter, the synchronization beacon is transmitted from the wireless transmission unit 200 at a fixed period. The synchronization beacon is a signal for specifying a time slot required for wireless communication (hereinafter referred to as "synchronous communication") in which TDMA (Time Division Multiple Connection) is performed between a plurality of fire alarms TR. . One cycle of the synchronization beacon is divided into a plurality of time slots, and time slots different from each other are allocated to all of the child base stations TR2, . Further, the message of the master base station TR1 toward the child base station TR2 is transmitted in the synchronization beacon, and includes the wireless message from the child base station TR2... toward the master base station TR1. The signal is stored in a time slot allocated to each sub base station and transmitted. Therefore, the collision of the wireless signals transmitted from the plurality of fire alarms TR (the primary base station TR1 and the sub base stations TR2, ...) can be surely avoided. Furthermore, the allocation of the time slots for the fire alarms TR may be fixed, but the allocation information of the time slots may be notified to the respective sub-base stations TR2... by the synchronization beacon transmitted by the autonomous base station TR1.

(Modification of Embodiment 2)

A modification of the second embodiment of the wireless communication system will be described with reference to Fig. 8 . In the second embodiment, when the radio wave level measuring unit 300 completes the measurement of the received signal strength during the intermittent reception, the radio wave level measuring unit 300 activates the arithmetic control unit 100 from the sleep state, and causes the arithmetic control unit 100 to receive the signal strength. The measurement result is compared with the reference value. On the other hand, in the present embodiment, when the radio wave level measuring unit 300 completes the measurement of the received signal strength during the intermittent reception, the radio wave level measuring unit 300 compares the measurement result of the received signal strength with the level of the reference value. . Here, when the measurement result of the received signal strength is equal to or greater than the reference value, the radio wave level measuring unit 300 activates the arithmetic control unit 100 from the sleep state and analyzes the received signal. When the measurement result of the received signal strength is smaller than the reference value, the radio wave level measuring unit 300 does not activate the arithmetic control unit 100, and the arithmetic control unit 100 maintains the sleep state until the counting of the timer 400 is completed. In addition, since the system configuration of this embodiment is the same as that of the second embodiment, the same components are denoted by the same reference numerals, and their description will be omitted.

Fig. 8 is a flow chart showing the operation at the time of intermittent reception, according to the flow The operation of this embodiment will be described.

The arithmetic control unit 100 sets a predetermined intermittent reception time to the timer 400 before transitioning to the sleep state, and causes the timer 400 to start the counting operation (step S21), and shifts to the sleep state.

When the counting of the timer 400 is completed (YES in step S22), the self-timer 400 outputs an activation signal to the arithmetic control unit 100, and causes the arithmetic control unit 100 to start from the sleep state (step S23). The arithmetic control unit 100 that has been activated from the sleep state sets an operation command to each of the wireless transmission unit 200 and the radio wave level measurement unit 300 (step S24), and switches the operation state to the sleep state (step S25).

When the operation command is set by the arithmetic control unit 100, the wireless transmission unit 200 autonomously performs the receiving operation (step S26). When the operation command is set by the calculation control unit 100, the radio wave level measurement unit 300 autonomously performs an operation of measuring the received signal strength of the signal received by the wireless transmission unit 200 (step S27). After measuring the received signal strength, the radio wave level measuring unit 300 compares the measured result of the received signal strength with the predetermined reference value (step S28).

When the measurement result of the received signal strength is equal to or greater than the reference value in the determination of step S28 (YES in step S28), the radio wave level measuring unit 300 determines that the wireless signal has been transmitted from the other fire alarm TR, and the arithmetic control unit 100 The start signal is output (step S29). The arithmetic control unit 100 that is activated from the sleep state causes the wireless transmission unit 200 to continue the reception operation based on the activation signal from the radio wave level measurement unit 300 (step S30), and analyzes the reception signal of the wireless transmission unit 200 (step S31). ). If receiving signals As a result of the analysis, when the fire signal is included in the received signal, the arithmetic control unit 100 causes the alarm unit 600 to perform the alarm operation described in the second embodiment based on the fire notification information, and interlocks with the fire alarm TR of the fire source. The notification operation is performed (step S32).

On the other hand, if the measurement result of the received signal strength is smaller than the reference value in the determination of step S28 (NO in step S28), the radio wave level measuring unit 300 determines that the wireless signal is not transmitted from the other fire alarm TR. The reception operation of the wireless transmission unit 200 is stopped (step S33). Subsequently, the radio wave level measuring unit 300 returns to the operation of step S1, sets an intermittent receiving time to the timer 400, starts the counting operation, and repeats the operations of step S2 and subsequent steps.

As described above, the arithmetic control unit 100 sets an operation command to the wireless transmission unit 200 and the radio wave level measurement unit 300 at the time of intermittent reception, and then shifts to the sleep state. Further, the wireless transmission unit 200 and the radio wave level measuring unit 300 autonomously perform predetermined operations, and the radio wave level measuring unit 300 compares the measurement result of the received signal strength with the reference value, and judges based on the comparison result. Whether or not the received signal is present. When the measurement result of the received signal strength is equal to or greater than the reference value, the radio wave level measuring unit 300 starts the arithmetic control unit 100, and the arithmetic control unit 100 analyzes the received signal received by the wireless transmitting unit 200, so that it can be surely received. Wireless signals from other fire alarms TR. Further, when the received signal strength is smaller than the reference value, the radio wave level measuring unit 300 stops the receiving operation of the wireless transmitting unit 200, so that the power consumption of the wireless transmitting unit 200 can be reduced. Further, the reception level measuring unit 300 does not cause the arithmetic control unit 100 to be activated. The arithmetic control unit 100 maintains the sleep state until the count of the timer 400 is completed, so that the power consumption of the arithmetic control unit 100 can be further reduced. Therefore, when the wireless base station (fire alarm TR) is battery-driven, the battery life can be extended and the battery replacement period can be extended, so that the burden of maintenance work can be reduced.

On the other hand, the wireless transceiver of the present invention can be applied not only to the above-described wireless communication system composed of a wireless communication device group, but also to the wireless transmitter Y1 of the remote control system as shown in FIG. With wireless receiver Y2. In addition to the at least transmission function of the wireless transceiver of the above-described embodiment, the wireless transmitter Y1 further includes a contact type capable of detecting whether a sensor or a pressure sensor is detected by an operation input, or The object detecting sensor YS that detects an object such as a human body or an obstacle in the vicinity by means of a non-contact type of passive detecting sensor of heat, light or vibration. The wireless receiver Y2 includes, in addition to the at least receiving function of the wireless transceiver, a device control unit YC that performs an environment control device that is responsible for environmental adjustment of a certain designated place, such as an air conditioner, a lighting device, or a device power source. A potentially low remote communication that interferes with wireless communication with the wireless transmitter Y1. The signal transmission between the device control mechanism YC and the above-mentioned device machine can be either wired or wireless. Thereby, the wireless transmitter that detects the presence of an object such as a human body or a barrier in the vicinity of the object detecting sensor YS causes the wireless transceiver to operate to indicate the situation detected by the object detecting sensor YS. The wireless signal Sig3 is sent to the wireless receiver Y2, and the wireless receiver Y2 receiving the wireless signal Sig3 is given a device control algorithm (algorithm) given to the device control mechanism YC in advance. (It may be only the power on/off of the equipment such as an air conditioner or a lighting machine), and depending on the content of the received wireless signal Sig3, it is determined in the equipment group such as the air conditioner, the lighting machine, or the equipment power source. It should be set as the operation mode of the device to be driven and the operation mode of the device, and perform remote control of the device in accordance with the result of the determination. Furthermore, at this time, the wireless receiver Y2 may also transmit, from its own wireless transceiver, to the wireless transmitter Y1, a reply back signal Sig4 indicating that the wireless signal Sig3 has been successfully received or has been interpreted. ACK signal). In this case, both the wireless transmitter Y1 and the wireless receiver Y2 must have both a wireless transmission function and a wireless reception function. The wireless transceiver of the present invention has high convenience in using different radio frequencies for transmission and reception, and thus can be preferably utilized.

(Embodiment 3)

Next, a third embodiment of the present invention will be described in detail with reference to Figs. 10 to 15 . As shown in FIG. 10, the wireless communication system according to the third embodiment includes a wireless transmission unit 200 that performs signal processing on a wireless signal received by the antenna 2 to convert a bit sequence into a pulse wave signal, and an arithmetic control unit 100. The information (data) contained in the wireless signal is obtained from the bit string output from the wireless transmission unit 200. Furthermore, the communication frame of the wireless signal is similar to the previous example, by a synchronization bit sequence (preamble) for obtaining bit synchronization, and a frame synchronization bit sequence for obtaining frame synchronization ( The unique word), the data corresponding to the above information, and the check code (for example, CRC) for error detection.

The wireless transmission unit 200 is provided with an amplification unit 2000 (corresponding to FIG. 1 LNA4), frequency conversion unit 2100 (corresponding to mixer 5 in Fig. 1), frequency selection unit 2200 (corresponding to IF filter and IF amplifier 7 in Fig. 1), demodulation unit 2300, sampling clock generation unit 240. Receive data buffer 250, shift register 260, frame synchronization detecting unit (hereinafter simply referred to as "synchronization detecting unit") 270, unique word (UW) register 280, and command processing ( Command decoding) section 290. In the wireless transmission unit 200 of the present embodiment, each of the above-described components is configured as a large-scale integrated circuit (LSI) integrated on one wafer.

The radio signal received by the antenna 2 is amplified by the amplification unit 2000, and then converted by the frequency conversion unit 2100 to an intermediate frequency lower than the radio frequency. The frequency conversion unit 2100 includes a local oscillator (not shown) that oscillates a signal of a local oscillation frequency equal to a difference frequency between the radio frequency and the intermediate frequency, and a frequency adjustment circuit (not shown) that adjusts the local oscillation. The frequency offset of the device. In a general wireless communication system, when a local oscillator generates a frequency deviation, the reference frequency may be indeterminate due to a residual frequency error caused by the frequency deviation, thereby demodulating the frequency-modulated wireless signal. This frequency error becomes the cause of false demodulation. Therefore, a function of correcting the frequency offset of the local oscillator to automatically cancel the influence of the frequency deviation, that is, a function called so-called automatic frequency adjustment (Auto Frequency Control) is mounted. Further, in the present embodiment, the frequency conversion unit 2100 is also provided with a frequency adjustment circuit to realize an automatic frequency adjustment function. Such a frequency adjustment circuit controls a local oscillator with a synthesizer (for example, using a grading) (fractional) PLL circuit frequency synthesizer) to adjust the frequency. Further, since such a frequency conversion unit 2100 is well known in the prior art, detailed description of the configuration and operation will be omitted.

The frequency selection unit 2200 is configured by a bypass filter, and selects and outputs a signal component (received signal) of a necessary frequency band only from an intermediate frequency signal frequency-converted by the frequency conversion unit 2100. The received signal is demodulated by the demodulation unit 2300 into a demodulated signal (baseband signal). The sampling clock generation unit 240 generates a sampling clock, and adjusts and outputs the phase of the sampling clock to sample the demodulated signal between the rising and falling. Moreover, the demodulated signal is sampled in synchronization with the sampling clock, and the sampled bit string (received data) is stored in the shift register 260. The shift register 260 has a capacity of the same number of bits as the number of bits of the unique word.

The synchronization detecting unit 270 compares the received data stored in the shift register 260 with the unique word stored in the UW register 280, and considers that the frame synchronization is obtained and outputs the frame when the bit columns of the two are identical. Synchronous detection signal (set to H level). Further, in the UW register 280, a unique word previously designated by the arithmetic control unit 100 is stored. Further, the sampling clock generation unit 240 continues to monitor the rise and fall of the demodulated signal, and if the timing of the rise or fall suddenly changes, it is regarded that the bit synchronization has deviated, and the synchronization deviation signal is output to the synchronization detecting portion. 270. When the self-sampling clock generation unit 240 receives the synchronization deviation signal, the synchronization detecting unit 270 stops the output of the frame synchronization detection signal (set to the L level).

The receiving data buffer 250 starts the frame in the self-synchronization detecting unit 270. When the output of the step detection signal (from the L level rises to the H level), the demodulated signal is sampled in synchronization with the sampling clock, and the sampled bit sequence (received data) is stored.

On the other hand, the arithmetic control unit 100 includes a central processing unit (CPU) 1000, a RAM 110, a ROM 120, an I/O unit 130, a first serial communication unit 140, and a second serial communication unit 150. And data bus (data bus) 160 and so on. The central processing unit 1000 executes various processes to be described later by executing a program stored in the ROM 120. The I/O unit 130 detects the rise and fall of the frame synchronization detection signal output from the synchronization detecting unit 270 of the wireless transmission unit 200, and notifies the central processing unit via the data bus 160 of the rising interruption and the falling interruption. 1000. When the I/O unit 130 notifies that there is a rising interrupt, the central processing unit 1000 starts the rising edge interrupt processing, and gives the received data output command to the second serial communication unit 150 via the data bus 160. Further, the second serial communication unit 150 transmits the received material output command given from the central processing unit 1000 to the command decoding unit 290 of the wireless transmission unit 200.

The command decoding unit 290 decodes the received material output command received from the second serial communication unit 150 and outputs it to the received data buffer 250. When receiving the data output command from the command decoding unit 290, the received data buffer 250 transmits the received data (bit row) stored in itself and the sampling clock input from the self-sampling clock generating unit 240 to the arithmetic control unit 100. The first serial communication unit 140. The first serial communication unit 140 transmits the received data and the sampling clock received from the received data buffer 250 of the wireless transmission unit 200 via The data bus 160 is transmitted to the central processing unit 1000. The central processing unit 1000 decodes the received data transmitted from the first serial communication unit 140 to acquire information (message) included in the wireless signal, and executes various processes based on the acquired information. When the central processing unit 1000 receives the information (message) of the predetermined length (1 frame), the central processing unit 1000 gives the reset command to the second serial communication unit 150 via the data bus 160. Further, the second serial communication unit 150 transmits the reset command given from the central processing unit 1000 to the command decoding unit 290 of the wireless transmission unit 200.

The command decoding unit 290 decodes the reset command received from the second serial communication unit 150 and outputs it to the sampling clock generation unit 240 and the synchronization detecting unit 270. When receiving the reset command, the sampling clock generation unit 240 stops the generation of the sampling clock and returns to the initial state. Similarly, the synchronization detecting unit 270 also stops the output of the frame synchronization detecting signal and returns to the initial state upon receiving the reset command. Furthermore, in the present embodiment, the I/O unit 130, the first serial communication unit 140, and the second serial communication unit 150 correspond to the interface.

However, in the wireless communication system according to the third embodiment, similarly to the prior art, even if the antenna 2 does not receive the wireless signal, the demodulation unit 2300 of the wireless transmission unit 200 may be affected by thermal noise or radio noise. And output a signal consisting of a random column of bits. Further, in such a random bit string, the same bit string as the unique word is included with a fixed probability. Therefore, the synchronization detecting unit 270 may erroneously detect the frame synchronization and output the frame synchronization detection signal. At this time, the central processing unit 1000 of the arithmetic control unit 100 also starts the rising edge interrupt processing in synchronization with the rise of the frame synchronization detection signal. The received data output command is transmitted by the second serial communication unit 150. As a result, the received data and the sampling clock are transmitted from the received data buffer 250 of the wireless transmission unit 200, and the central processing unit 1000 decodes the received data.

Here, the sampling clock generation unit 240 of the wireless transmission unit 200 continues to monitor the bit sequence of the demodulated signal demodulated by the demodulation unit 2300, since the bit width (pulse width) of the random bit column is not Fixed, so immediately judged to be the synchronization deviation and stop the output of the sampling clock. When the output of the sampling clock is stopped, the synchronization detecting unit 270 also stops the output of the frame synchronization detecting signal. Further, in the central processing unit 1000 of the arithmetic control unit 100, if the frame synchronization detection signal is stopped (from the H level to the L level) before the bit string of the predetermined length is received from the received data buffer 250, Then, the falling edge interrupt processing is started and the data (bit row) received from the received data buffer 250 is discarded, and a reset command is output.

As has been explained, in the previous example, when a regular wireless signal is received immediately after a erroneous synchronization due to the influence of thermal noise or radio noise, the wireless signal may not be normally received. On the other hand, in the wireless communication system according to the third embodiment, even when a normal wireless signal is received immediately after erroneous synchronization due to the influence of thermal noise or radio noise, the regular wireless signal can be surely received. .

Hereinafter, the wireless communication of the third embodiment will be described in detail with reference to the timing chart of FIG. 1 when erroneous synchronization occurs due to the influence of thermal noise or radio noise, and the regular wireless signal is received immediately after a short synchronization deviation. The action of the system. Among them, "N" in Figure 1 indicates noise, and "P" indicates Preamble, "U" means unique word, number "1", "2", ... means data, and "output" means receiving data output command.

When the erroneous detection occurs at the time t=t1 and the frame synchronization detection signal rises, the central processing unit 1000 of the arithmetic control unit 100 starts the rising edge interruption processing, but the central processing unit 1000 passes the second serial communication unit 150. Before the transmission of the data output command to the wireless transmission unit 200 (time t=t3) (time t=t2), the synchronization deviation occurs and the frame synchronization detection signal falls. At this time, in the previous example, before the falling of the frame synchronization detection signal, the control signal is output from the microcomputer unit 1300, so that the frame synchronization detection signal falls despite the occurrence of the synchronization deviation, but the self-reception buffer is synchronized with the drop of the control signal. The device 124 outputs the received data to the microcomputer unit 1300 (refer to time t=t4 in Fig. 18).

However, in the present embodiment, as shown in FIG. 10, the frame synchronization detection signal output from the synchronization detecting unit 270 is also input to the command decoding unit 290, and the command decoding unit 290 outputs a command to the received data (the output in FIG. 1). The signal is calculated by the logical product of the frame synchronization detection signal, and is output to the received data buffer 250 only when the frame synchronization detection signal and the received data output command are simultaneously input (both are H-bits). Output the command. Therefore, in FIG. 11, when the command decoding unit 290 receives the received data output command (time t=t3), it becomes a synchronization deviation, and the frame synchronization detection signal is stopped (becomes an L level), so the command decoding unit is not self-instructed. 290 outputs the received data output command, and does not output the received data from the received data buffer 250.

And, when the transmission of the received data output command is completed (time t=t4), the central processing unit 1000 starts the falling edge interrupt processing in response to the falling interrupt of the I/O unit 130, and outputs a reset command. Furthermore, since the received data is not currently output from the received data buffer 250, the central processing unit 1000 does not have to discard the data received from the received data buffer 250 in the falling edge interrupt processing.

Then, when the normal wireless signal is received by the antenna 2 and the frame synchronization detection signal rises from the time point (time t=t2) at which the synchronization is deviated (time t=t5), the central processing unit 1000 corresponds to the I/O. The rising interrupt of the unit 130 starts the rising edge interrupt processing (time t=t6), and the received data output command is transmitted from the second serial communication unit 150 to the command decoding unit 290 (time t=t7 to t8). Since the frame synchronization detection signal is at the H level at the time of receiving the received data output command (ACT signal), the command decoding unit 290 outputs the received material output command to the received data buffer 250. And, the received data buffer 250 receives the received data output command and outputs the received data and the sampling clock (time t=t8). The received data buffer 250 starts the output of the received data from the point of receiving the received data output command, and does not output the received data until the received data output command is received as in the previous example shown in FIG. Therefore, in the first serial communication unit 140 of the arithmetic control unit 100, the data stored in the received data buffer 250 can be correctly received from the first (the data of "1") in order.

As described above, in the wireless communication system according to the third embodiment, the command decoding unit 290 of the arithmetic control unit 100 starts the output of the frame synchronization detection signal from the synchronization detecting unit 270 until the output of the frame synchronization detection signal is stopped. When the received data output command is not received, even until The central processing unit 1000 of the arithmetic control unit 100 outputs the received data output command from the central processing unit 1000 of the arithmetic control unit 100 until the synchronization detection unit 270 starts the output of the next frame synchronization detection signal, and does not output the received data stored in the received data buffer 250. . As a result, as described above, the regular wireless signal can be correctly received immediately after the erroneous synchronization. Further, in the present embodiment, there is an advantage that it can be realized with a relatively simple configuration, that is, the command decoding unit 290 operates on the logical product of the received data output command and the frame synchronization detection signal, and the frame synchronization detection signal When the received data output command is not simultaneously input (at least either of them is L-level), the received data output command is not output to the received data buffer 250.

However, as described above, it is generally considered that when the erroneous synchronization is eliminated in a short time (becoming a synchronization deviation), it is often the case that a regular wireless signal is received. On the other hand, when erroneous synchronization due to thermal noise or the like occurs, the local oscillation frequency adjusted by the frequency adjustment circuit of the frequency conversion unit 2100 may deviate greatly from the local oscillation frequency corresponding to the original wireless signal. (Refer to "AFC Frequency" in Figure 12).

Therefore, as shown in FIG. 12, when the synchronization is deviated (time t=t2), the frequency offset adjustment (AFC frequency) of the frequency adjustment circuit in the frequency conversion unit 2100 of the wireless transmission unit 200 is initialized. Then, the time until the frequency adjustment circuit completes the adjustment of the frequency offset can be shortened with respect to the regular wireless signal.

Alternatively, as shown in FIG. 13, when the output of the received data output command is output (time t=t4), the output of the frame synchronization detection signal is stopped, and the central processing unit 1000 transmits the initialization via the second serial communication unit 150. Life Therefore, the adjustment of the frequency offset performed by the frequency adjustment circuit can also be initialized.

Further, in addition to the configuration in which the command decoding unit 290 calculates the logical product of the received material output command and the frame synchronization detection signal, and determines whether or not the received data output command can be output to the received data buffer 250, the following method may be employed. . That is, as shown in FIG. 14, the output of the frame synchronization detection signal is confirmed before outputting the received data output command according to the frame synchronization detection signal (refer to time t=t3), and if the output of the frame synchronization detection signal is stopped The central processing unit 1000 does not output the received data output command from the command decoding unit 290. Further, the broken line of "output" at the time t = t3 - t4 in Fig. 14 indicates that the output of the received data output command has been suspended. Thus, as shown in FIG. 14, the falling edge interrupt processing is not performed even if the falling interrupt of the frame synchronization detecting signal is received from the I/O unit 130, and the rising edge interrupt processing is immediately executed after the rise of the frame synchronization detecting signal. Therefore, the maximum length of the received material buffer 250 can be shortened as compared with the configuration shown in FIG.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

<p>2, 2a antenna</p><p>3RF filter</p><p>4Low noise amplifier</p><p>5 Mixer</p><p>6Intermediate frequency filter</p><p>7Intermediate frequency amplifier (IF amplifier)</p><p>8Demodulation Department</p><p>9Send Department</p><p>10Antenna Switching Department</p><p>10a, 10b, 11a, 11b, 23a, 23b, 24a, 24b switch terminals</p><p>10c, 11c, 23c, 24c shared terminals</p><p>11Transfer and Switching Department</p><p>12Control Department</p><p>20Standard Oscillation Department</p><p>21Multiplication</p><p>22 PLL Department</p><p>231st switching department</p><p>242nd switching department</p><p>30Voltage Controlled Oscillator</p><p>311/n divider</p><p>32Programmable Divider</p><p>33 phase comparator</p><p>34loop filter</p><p>35Charge pump</p><p>100Accounting Control Department</p><p>100a Memory Department</p><p>110, 131RAM</p><p>111Demodulation Department</p><p>112, 240Sampling clock generation department</p><p>120ROM</p><p>121Box code register</p><p>122 Frame Synchronization Offset Register</p><p>123 Frame Synchronization Detection Department</p><p>124 Receive buffer</p><p>130I/O Department</p><p>132Control Department</p><p>133Transportation Department</p><p>1401st serial communication department</p><p>1502nd Serial Communications Department</p><p>160 data bus</p><p>200Wireless Collection Department</p><p>250Receive data buffer</p><p>260Shift register</p><p>270 Frame synchronization detection unit (synchronization detection unit)</p><p>280 unique word register</p><p>290Command Processing Unit (Command Decoding Unit)</p><p>300Electric wave level measurement department</p><p>400Timer</p><p>500Fire Sensory Department</p><p>600Warning Department</p><p>700Battery Power Supply Department</p><p>1000Antenna/Central Processing Department</p><p>1100RF Department</p><p>1200 face</p><p>1300Microcomputer Department</p><p>2000Amplification</p><p>2100 Frequency Conversion Department</p><p>2200 Frequency Selection Department</p><p>2300Demodulation Department</p><p>C1 Bypass capacitor</p><p>P preamble</p><p>R current limiting resistor</p><p>S1 optical sensor</p><p>S2 Thermal Sensor</p><p>S3Chemical Sensor</p><p>S4 Pressure Sensor</p><p>Sig1first wireless signal</p><p>Sig2second wireless signal</p><p>Sig3 wireless signal</p><p>Sig4 reply signal</p><p>SW1, SW2, SW3 switch</p><p>T1, t2, t3, t4, t5, t6, t7, t8</p><p>TR1Fire alarm/primary base station</p><p>TR2 fire alarm/sub-base station</p><p>U unique word</p><p>VccExternal power supply (system power supply)</p><p>X1, X2, X3, X4 wireless communication machines</p><p>X100Display Notification Department</p><p>X101Sound Notification Department</p><p>Y1Wireless transmitter</p><p>Y2 wireless receiver</p><p>YC Equipment Control Agency</p><p>YS object detection sensor</p>

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram schematically showing a wireless communication system of the present invention.

Fig. 2 is a block diagram showing a wireless transceiver according to the first embodiment of the present invention.

3(a) and 3(b) are circuit diagrams of essential parts of a local oscillator of the wireless transceiver according to the first embodiment of the present invention.

4(a) and 4(b) are circuit diagrams showing still another main part of a local oscillator of the wireless transceiver according to the first embodiment of the present invention.

Fig. 5 is a system configuration diagram of a wireless communication device and a wireless communication system on which the wireless transceiver according to the first embodiment of the present invention is mounted.

Fig. 6 is a block diagram showing a fire alarm device (main base station and sub base station) according to the second embodiment.

Fig. 7 is a flow chart for explaining an intermittent receiving operation of the fire alarm device of the second embodiment.

Fig. 8 is a flowchart showing a modification of the intermittent receiving operation of the fire alarm of the second embodiment.

Fig. 9 is a system configuration diagram of a device control system using the wireless transmitter and the wireless receiver according to the first embodiment.

Fig. 10 is a block diagram showing the main part of a wireless communication system according to a third embodiment of the present invention.

Fig. 11 is a timing chart for explaining the operation of the third embodiment of the present invention.

Fig. 12 is a timing chart for explaining the operation of the third embodiment of the present invention.

Fig. 13 is a timing chart for explaining the operation of the third embodiment of the present invention.

Fig. 14 is a timing chart for explaining the operation of the third embodiment of the present invention.

Fig. 15 is a block diagram showing a prior example.

Fig. 16 is a timing chart for explaining the operation of the previous example.

Fig. 17 is a timing chart for explaining the operation of the previous example.

Fig. 18 is a timing chart for explaining the operation of the previous example.