Wireless communication system, wireless device and wireless communication method

The present invention relates to, for example, a wireless communication system using an analog FM (frequency modulation) method, a wireless device, and a wireless communication method, and particularly refers to voice signals and data (hereinafter referred to as "communication data") communicated wirelessly. ) Is scrambled to prevent the communication data from being decoded. The present invention relates to a wireless communication system, a wireless device, and a wireless communication method.

For example, in analog FM wireless communication systems, in recent years, scrambling processing for performing various concealment has been provided in order to prevent leakage of communication data. The scrambling process of the prior art for such concealment will be described with reference to the drawings. FIG. 5 shows the configuration of 10 analog FM wireless communication systems (hereinafter referred to as wireless communication systems) based on the prior art. The wireless communication system 10 is composed of a base station 100 as a master station and a mobile station 200 such as a plurality of mobile terminals as a slave station, and the base station 100 and the mobile station 200 communicate wirelessly.

The processing on the transmitting side and the receiving side of the radio 300 of the base station 100 and the mobile station 200 in such a wireless communication system 10 will be described with reference to FIG.

First, the processing on the transmitting side of the radio 300 will be described with reference to FIG. 6 (1). When the DSP (Digital Signal Processing) 20 outputs an audio signal to the audio signal scramble processing unit 21, the audio signal scramble processing unit 21 scrambles the audio signal and outputs the scrambled audio signal to the FM modulation processing unit 24. To do. When the DSP 20 outputs the data to the data scramble processing unit 22, the data scramble processing unit 22 scrambles the data and outputs the scrambled data to the MSK (minimum-shift keying) modulation processing unit 23. When the scrambled data is input, the MSK modulation processing unit 23 performs minimum shift keying that narrows the occupied band and outputs it to the FM modulation processing unit 24. In this way, noise can be reduced by performing the minimum shift keying that narrows the occupied band. When the scrambled audio signal or data is input, the FM modulation processing unit 24 modulates the audio signal or data into a carrier wave (radio wave) and transmits the scrambled audio signal or data through the antenna 25.

Next, the processing on the receiving side of the radio 300 will be described with reference to FIG. 6 (2). When the FM demodulation processing unit 29 inputs the carrier wave of the scrambled audio signal or data received by the antenna 25, the FM demodulation processing unit 29 demodulates the carrier wave and outputs it to the audio signal descramble processing unit 26 when the carrier wave is an audio signal. When the carrier wave is data, it is output to the MSK demodulation processing unit 28. When the scrambled audio signal is unscrambled, the audio signal descramble processing unit 26 outputs the descrambled audio signal to the DSP 20. The MSK demodulation processing unit 28 outputs the scrambled data to the data descramble processing unit 27 after performing the minimum shift demodulation. When the scrambled data is unscrambled, the data descramble processing unit 27 outputs the descrambled data to the DSP 20.

Next, the procedure for passing the scrambled code between the base station 100 and the mobile station 200 of the wireless communication system 10 will be described with reference to FIG. 7, which is a sequence diagram until the base station 100 and the mobile station 200 establish communication. As shown in FIG. 7, first, in step S201, when the scramble code B is specified, the base station 100 transmits the "notification information" in which the scramble code A is set to the mobile station 200. This "notification information" is scrambled with a predetermined scramble code A. Next, in step S202, when the mobile station 200 receives the "notification information", when the mobile station 200 requests registration, the mobile station 200 returns the "registration request" to the base station 100. This "registration request" is scrambled with a predetermined scramble code A. Next, in step S203, when the base station 100 receives the "registration request", it returns a "registration response" notifying that it has agreed to the "registration request" to the mobile station 200. This "registration response" is scrambled with the scramble code B set in the "notification information". Next, in step S204, when the mobile station 200 receives the "registration response", it returns a "response confirmation" notifying that the "registration response" has been confirmed to the base station 100. This "response confirmation" is scrambled with the scramble code B. When the base station 100 receives the "response confirmation", the communication between the base station 100 and the mobile station 200 is established, scrambled by the scramble code B when transmitting the subsequent communication data, and the scramble code when receiving the communication data. B descrambling.

Conventionally, the base station 100, which is a higher-level device in the wireless communication system 10, specifies a scramble code, and the base station 100 and the mobile station 200 establish communication by the designated scramble code. For example, in the digital mobile wireless system of Patent Document 1, the wireless terminal station can change the scramble code of the wireless terminal station by the scramble code set in the "notification information" transmitted from the wireless base station. It makes it possible to establish communication with other wireless base stations that use a scrambled code for communication channels that are different from the wireless system to which they originally belong.

<p num="0008"><patcit num="1"><text>JP 2005-244575</text></patcit></p>

<p num="0009"> The radio wave on the transmitting side using the analog FM method according to the prior art can be duplicated by the measuring instrument 30 having the functional configuration shown in FIG. 8 which is generally used. The procedure in which the measuring instrument 30 replicates the radio waves of the base station 100 will be described with reference to FIG. First, the modulation analyzer 32 demodulates the radio wave of the base station 100 received from the antenna 31, and outputs the demodulated audio signal to the receiving side recorder 33. The receiving side recorder 33 records the received audio signal as an audio signal, and replicates the recorded audio signal to the transmitting side recorder 34. When the duplication of the recorded audio signal is completed, the transmitting recorder 34 outputs the audio signal to the signal generator 35. The signal generator 35 demodulates the input audio signal and transmits it from the antenna 31. In this way, in the wireless communication system 10 using the analog FM system, when the base station 100, which is a higher-level device on the transmitting side, specifies the scramble code as in the digital system, a third party uses the measuring instrument 30 to specify the base station. The radio waves transmitted from 100 can be duplicated. As a result, communication with the mobile station 200 can be established, so that there is a problem that an unauthorized third party can perform a radio jack in the wireless section.</p><p num="0010"> The present invention has been made in view of such a situation, and an object of the present invention is to provide a wireless communication system, a wireless device, and a wireless communication method capable of solving the above problems.</p>

<p num="0011"> The wireless communication system of the present invention is a wireless communication system having a master station and a slave station for wireless communication, and the master station scrambles the broadcast information with a predetermined first scramble code to the slave station. The slave station includes a notification information transmitting means for transmitting, and when the slave station receives the notification information, the slave station scrambles the registration request in which the second scramble code is set with the first scramble code and transmits the registration request to the master station. A transmission means is provided, and subsequent communication data between the master station and the slave station is scrambled with the second scramble code. Further, the second scramble code of the wireless communication system is characterized in that the individual number of the slave station is used. Further, the second scramble code of the wireless communication system is characterized in that the time from the power-on of the slave station is used. Further, the time from turning on the power of the slave station of the wireless communication system is counted in a predetermined unit time. Further, the radio device of the present invention is a radio device provided in a slave station of a wireless communication system, and receives broadcast information received from a master station scrambled with a predetermined first scramble code. A means and a registration request transmitting means for scrambling and transmitting a registration request for which a second scramble code is set when the broadcast information is received are provided, and subsequent communication data with the master station is provided. Is scrambled with the second scramble code. Further, the wireless communication method of the present invention is a wireless communication method in a slave station of a wireless communication system, and receives notification information received from a master station scrambled with a predetermined first scramble code. A process and a registration request transmission step of scrambling and transmitting a registration request in which a second scramble code is set when the broadcast information is received are provided, and subsequent communication data with the master station is provided. Is scrambled with the second scramble code.</p>

<p num="0012"> According to the present invention, even when a third party duplicates and transmits a radio wave from a master station, a wireless communication system that makes it impossible to establish communication with a slave station using the radio wave duplicated by the third party. Provide a radio wave and a wireless communication method.</p>

<figref num="1">It is a figure which shows the sequence until the base station and the mobile station which concerns on embodiment of this invention establish communication.</figref><figref num="2">It is a figure explaining the structure of the air format and the scramble procedure which concerns on embodiment of this invention.</figref><figref num="3">It is a figure which shows the structure of the PN (15, 14) which concerns on embodiment of this invention.</figref><figref num="4">It is a flowchart of scramble processing and descramble processing which concerns on embodiment of this invention.</figref><figref num="5">It is a figure which shows the structure of a wireless communication system.</figref><figref num="6">It is a figure which shows the processing flow of the transmitting side and the receiving side of a radio.</figref><figref num="7">It is a figure which shows the sequence until the base station and the mobile station which concerns on a prior art establish communication.</figref><figref num="8">It is a figure which shows the functional structure of the measuring instrument which concerns on the prior art.</figref>

The configuration of the wireless communication system 10 according to the embodiment of the present invention is the same as that of the wireless communication system 10 shown in FIG. 5, and the processing flow on the transmitting side and the receiving side of the base station 100 and the mobile station 200 is shown in FIG. The processing flow of the transmitting side and the receiving side of the base station 100 and the mobile station 200 shown is the same. In the embodiment of the present invention, the procedure for delivering the scrambled code of the wireless communication system 10 is different from the procedure for delivering the conventional scrambled code. In the wireless communication system 10 as the embodiment shown in FIG. 5, the base station 100 is used as the master station and the mobile station 200 is used as the slave station, but the master station is limited to the base station in the present invention. is not it. For example, the master station may be a radio that is the main of a plurality of slave stations (has a special function that the plurality of slave stations do not have), or controls and manages the mobile station 200 (for example, restricts operations). ) It may be a master station radio. When the master station limits the operation, the mobile station 200 may be configured to release the operation restriction for a predetermined time by performing the communication shown in FIG. 1 with the master station. Further, in the wireless communication system of FIG. 5, a mobile station is taken as an example as a wireless terminal as a slave station, but it may not necessarily be a mobile station but a wireless device that is used fixedly.

First, regarding the procedure for passing the scrambled code between the base station 100 and the mobile station 200 of the wireless communication system 10 according to the embodiment of the present invention, FIG. 1 which is a sequence until the base station 100 and the mobile station 200 establish communication is used. I will explain. As shown in FIG. 1, first, in step S101, the base station 100 transmits "notification information" to the mobile station 200. This "notification information" is scrambled with a predetermined scramble code A. Next, in step S102, when the mobile station 200 receives the "notification information", the mobile station 200 requests registration, and when the scramble code C is specified, the mobile station 200 makes a "registration request" in which the scramble code C is set to the base station 100. Return to. This "registration request" is scrambled with a predetermined scramble code A. Next, in step S103, when the base station 100 receives the "registration request", it returns a "registration response" notifying that it has agreed to the "registration request" to the mobile station 200. This "registration response" is scrambled with the scramble code C set in the "registration request". Next, in step S104, when the mobile station 200 receives the "registration response", it returns a "response confirmation" notifying that the "registration response" has been confirmed to the base station 100. This "response confirmation" is scrambled with the scramble code C. When the base station 100 receives the "response confirmation", the communication between the base station 100 and the mobile station 200 is established, scrambled by the scramble code C when transmitting the subsequent communication data, and the scramble code C when the communication data is received. Descrambles with.

Next, the scramble processing and the descramble processing of the radio 300 of the mobile station 200 will be described. The scramble processing is performed by the audio signal scrambling processing unit 21 or the data scrambling processing unit 22 (hereinafter, referred to as scramble processing unit) shown in FIG. 6 (1). The descrambling process is performed by the audio signal scramble processing unit 26 or the data scramble processing unit 27 (hereinafter, referred to as descrambling processing unit) shown in FIG. 6 (1).

First, the signal format (hereinafter referred to as air format) 40 of communication data transmitted / received in the wireless section between the base station 100 and the mobile station 200 will be described with reference to FIG. 2 (1). As shown in FIG. 2 (1), the air format 40 is composed of a bit synchronization signal 41, a frame synchronization signal 42, and a message signal 43. The bit synchronization signal 41 and the frame synchronization signal 42 use the MSK format of analog simple radio. Such an air format 40 has, for example, a modulation speed of 1200 bps and a mark frequency of 1200 H._Z"1", space frequency is 1800H_ZIt is "0". The bit synchronization signal 41 is a 48-bit bit string composed of two values of 1 and 0 as shown in FIGS. 2 (1) and 2 (a) for notifying the receiving side of the bit detection timing of the transmitted signal. The frame synchronization signal is a 31-bit M-sequence code (Maximum period sequence) consisting of two values of 1 and 0 as shown in Fig. 2 (1) (b) to inform the receiving side of the frame detection timing of the transmitted signal. : Maximum periodic sequence code) is a randomized bit string. The M-sequence code is a pseudo-random number sequence in the PN code (Pseudo Noise: pseudo-random code), which is the key to encryption. As shown in FIGS. 2 (1) and 2 (c), the message signal 43 is a bit string composed of a message message (64 bits) and a CRC code (16 bits). The CRC code is a generated polynomial (1 + X) that detects signal errors in message messages.⁵+ X¹²+ X¹⁶).

The scrambling procedure for such an air format 40 will be described with reference to FIG. 2 (2). First, as shown in FIGS. 2 (2) and 2 (a), the message signal 43 composed of the message message and the CRC code is taken out from the air format 40. Next, the message signal 43 is scrambled by the scramble code C as shown in FIGS. 2 (2) and 2 (a). Next, the scrambled message signal is stored in the air format 40 as shown in FIGS. 2 (2) and 2 (c). The descramble procedure is the same as the scramble procedure in FIG. 2 (2) except that the message signal 43 is descrambled by the scramble code C in FIG. 2 (2) (a).

Next, the scramble code A and the scramble code C shown in FIG. 1 will be described. The scramble code A can be any code predetermined by the base station 100 and the mobile station 200. For example, a part of the serial number of the base station 100 or the mobile station 200 can be a scramble code A. The scramble code C is a scramble code designated by the mobile station 200, and is set to a different value for each mobile station 200, and is set to a different value each time a "registration request" is transmitted even in the same mobile station 200. Therefore, the initial value of the scramble code C is determined using the individual number of the mobile station 100 and the time since the power of the mobile station 100 is turned on.

When the scramble code C generated from the individual number of the mobile station 100 and the time since the power of the mobile station 100 is turned on is, for example, a 15-bit bit string, for example, the individual number is 3 bits and the count time. Is assigned to be 12 bits. In such a case, 8 (= 2) by 3 bits of the individual number³) Mobile station 200 can be identified. Also, 12 bits of count time (4096 = 2)¹²), And if 1 count time is 5 msec, 4095 x 5 msec = 20475 msec (20.475 seconds) will be one lap.

Further, in order to scramble the message signal 43, the bit string of the message signal 43 is multiplied by the PN code PN (15, 14) shown in FIG. 3 whose initial value is the scramble code C. Randomize. PN (15, 14) is S as shown in Fig. 3.₀From S₁₄It is a bit string provided with 15 bits of. Shift this PN (15, 14) bit by bit to the right in order, and S₀Bit and S₁Set the Bit ExOR (Exclusive OR) value to S₁₄Pseudo-random numbers are generated one after another by using bit values and repeating this. That is, when the scramble code C is set as the initial value of the PN code, a pseudo-random number of the scramble code C is generated.

Next, the scramble procedure of the message signal 43 by the PN (15, 14) executed by the scramble processing unit will be described in the step order of the flowchart shown in FIG. 4 (1).

(Step S11) First, the scramble processing unit creates a scramble code C consisting of an individual number and a count time. The current count time is set in the count time. A pattern number is assigned to the scramble code C, and the pattern number is associated with the message signal 43 and stored in a storage unit (not shown) such as an auxiliary storage device.

(Step S12) Next, the scramble processing unit sets the scramble code C created in step S11 to the initial register value of PN (15, 14).

(Step S13) Next, the scramble processing unit S of the bit string of the register of PN (15, 14).₀S₁S₂S₃... Is output in order.

(Step S14) Next, when the scramble processing unit inputs the message signal 43, the S of the bit string of the PN (15, 14) output in step S13 from the beginning of the message signal 43.₀S₁S₂S₃When the scrambled message signal 43 is output by performing the Bit-by-bit ExOR (exclusive OR) operation with ..., The scramble processing ends.

Next, the descramble procedure of the message signal 43 by the PN (15, 14) executed by the descramble processing unit will be described in the step order of the flowchart shown in FIG. 4 (2).

(Step S21) First, the descramble processing unit retrieves the scramble code C of the pattern number corresponding to the message signal 43 from the storage unit 20a.

(Step S22) Next, the descramble processing unit sets the scramble code C taken out in step S21 in the register of PN (15, 14).

(Step S23) Next, the descramble processing unit S of the bit string of PN (15, 14).₀S₁S₂S₃... Is output in order.

(Step S24) Next, when the descramble processing unit inputs the scrambled message signal 43, the descramble processing unit S of the bit string of the PN (15, 14) output in step S23 from the beginning of the message signal 43.₀S₁S₂S₃When the bit-by-bit ExOR (exclusive OR) operation is performed and the descrambling message signal 43 is output, the descramble processing ends.

As described above, in the wireless communication system 10, the mobile station 200 specifies the scramble code instead of the base station 100 which is the higher-level device on the transmitting side specifies the scramble code. Therefore, a third party uses the measuring instrument 30 to specify the scramble code. Even if the radio wave transmitted from is duplicated, the scramble code cannot be duplicated. Therefore, since communication cannot be established with the mobile station 200, it is possible to prevent a radio jack in the radio section by an unauthorized third party.

In the embodiment, the scramble code C is described as the individual number of the mobile station 100 and the count time after the power of the mobile station 100 is turned on. It is possible to use the scramble code C as other data that has a different value each time it is transmitted. In addition, the scramble code C is a 15-bit bit string, and 3 bits are assigned to the individual number and 12 bits are assigned to the count time, but the present invention is not limited to this. For example, it is possible to assign 5 bits to the individual number and 10 bits to the count time.

Such a wireless communication system, a radio, and a wireless communication method of the present invention move using the radio waves duplicated by the third party even when the radio waves from the base station are duplicated and transmitted by the third party. It is possible to prevent the establishment of communication with the station.

Although the present invention has been described above with reference to specific embodiments, it goes without saying that the above embodiments are examples of the present invention and are not limited to these embodiments.

The features of the above embodiments can be summarized as follows. (1) The wireless communication system of the present invention is a wireless communication system having a master station and a slave station that perform wireless communication, and the master station scrambles the broadcast information with a predetermined first scramble code. The slave station is provided with a notification information transmitting means for transmitting to the slave station, and when the slave station receives the notification information, it scrambles a registration request in which a second scramble code is set with the first scramble code and transmits the registration request to the master station. It is characterized in that it is provided with a registration request transmitting means for scrambling the subsequent communication data between the master station and the slave station with the second scramble code. (2) The wireless communication system of (1) is characterized in that the second scramble code uses the individual number of the slave station. (3) The wireless communication system according to (1) or (2) is characterized in that the second scramble code uses the time from the power-on of the slave station. (4) The wireless communication system of (3) is characterized in that the time from the power-on of the slave station is counted in a predetermined unit time. (5) The wireless communication system according to any one of (1) to (4) is characterized in that the air format message signal is scrambled. (6) The wireless communication system according to any one of (1) to (5) is characterized in that the communication data scrambled by the first scramble code is descrambled by the first scramble code. There is. (7) The wireless communication system according to any one of (1) to (5) is characterized in that the communication data scrambled by the second scramble code is descrambled by the second scramble code. There is. (8) The radio device of the present invention is a radio device provided in a slave station of a wireless communication system, and is a notification information that receives notification information scrambled with a predetermined first scramble code from a master station. A receiving means and a registration request transmitting means for scrambling and transmitting a registration request in which a second scramble code is set when the broadcast information is received are provided, and subsequent communication with the master station is provided. The data is scrambled with the second scramble code. (9) The wireless communication method of the present invention is a wireless communication method in a slave station of a wireless communication system, and is a notification information for receiving notification information scrambled with a predetermined first scramble code from a master station. A reception step and a registration request transmission step of scrambling and transmitting a registration request in which a second scramble code is set when the broadcast information is received are provided, and subsequent communication with the master station is provided. The data is scrambled with the second scramble code.

The present invention is suitable for wireless communication systems, radios, and wireless communication methods, but is not limited to wireless communication systems, radios, and wireless communication methods, but is not limited to scrambled communication systems, communication devices, and communications. The method is generally applicable.

10 Wireless communication system 20 ... DSP 20a Memory 21 ... Audio signal scramble processing unit 22 Data scramble processing unit 23 MSK modulation processing unit 24 ... FM modulation processing unit 25 Antenna 26 Audio signal descramble processing unit 27 Data descramble processing department 28 MSK demodulation processing unit 29 FM demodulation processing unit 30 Measuring instrument 31 Antenna 32 ... Modulation analyzer 33 Receiving recorder 34 Transmitter recorder 35 Signal generator 40 Air format 41 Bit synchronization signal 42 Frame synchronization signal 43 Message signal 43a Message message 43b CRC code 100 Base station (master station) 200 Mobile station (slave station) 300 Radio