Arrangement for controlling a transmitter-receiver pair, in particular base stations and mobile units of a cordless telephone system

Description: TECHNICAL FIELD [Detailed description of the invention]

The present invention relates to a control device for a base station and / or a mobile unit transmitter / receiver, which is described in the superordinate concept of claim 1, in particular, in a cordless telephone system. For example, in a system based on the TDMA principle (Time Devision Multiple Access) (for example, a DECT cordless system, a CT2 cordless system, etc.) and a system based on the CDMA principle (Code Division Multiple Access), the voice to be transmitted is compressed on the transmitting side. And transmitted from the transmitter of the transmitting unit (base station, mobile) within the framework of the wireless connection, received and stretched by the receiver of the receiving unit (mobile, base station) (burst technology). Can be configured. From West Germany Utility Model No. 2249922, for example, a mobile TDM wireless telecommunication system having the above-mentioned characteristics is known. An object on which the present invention is based is, in particular, that the base station and / or mobile part of a cordless telephone system operates reliably with as little energy as possible. This problem is solved by the feature portion of claim 1, starting from the device according to the superordinate concept of claim 1. Especially in the base station and / or mobile part of the cordless telephone system, the energy used for the operation of the base station and / or the mobile part excluding the module necessary for frame clock monitoring (for example, the base station and / or the base station and /). Or to reduce (in mobile transmitter / receiver)-especially when the above equipment is constantly powered, eg via a battery, the transmitter / receiver is cyclic in transmission technology (eg TDMA or CDMA schemes). The transmission / reception bursts (Fig. 4) that occur at regular time intervals are switched on somewhat earlier in time. At that time, this early time is, for example, the time required by the electronic element in the transmission / reception device from the time of switch-on to the start of the transmission / reception burst. In addition, it is possible to accelerate the time for guaranteeing that the transmitter / receiver is operating during the transmit / receive burst period (claim 2). The transmitter / receiver is shut off at the end of the transmit / receive burst, just as the transmitter / receiver is switched on for the entire duration of the transmit / receive burst. Correspondingly to shutting down the transmitter / receiver to ensure that the transmitter / receiver is also switched on for the entire duration of the transmit / receive burst, as in the case of switching on the transmitter / receiver. A partial delay time can also be set (claim 3). Advantageous examples of the present invention are described in other claims. According to claim 4, the transmitter / receiver is, on the one hand, a plurality of sub-devices (central function) such as a switching device, an amplifier and an interface device, and on the other hand, simultaneously as described in claim 5 and in claim 6. Includes transmitters and receivers that are switched on and off in time as described. Examples of the present invention will be described with reference to the drawings. FIG. 1 is a block circuit diagram of a device for controlling a transmitter / receiver in a base station or mobile unit of a cordless telephone system. FIG. 2 is a block diagram showing the basic configuration of the transmitter / receiver in FIG. Figure 3 shows the TDMA time frame in a cordless telephone system according to the DECT standard. FIG. 4 is a diagram showing the time relationship between the transmission / reception burst and the operation of the transmission / reception devices shown in FIGS. 1 and 2. FIG. 1 shows the basic circuit configuration of the base station FT or mobile unit PT of a cordless telephone system. Both the base station FT and the mobile unit PT are peripheral circuits that are grouped into the radio element RE, which is also referred to as the transmitter / receiver RE-T / PE-R, the control element CE, and the functional block "peripheral element". Includes parts (Peripheral elments). In the following description, the cordless telephone system starts from being designed based on the DECT standard (Digital European Cordless Telecommunication). However, the present invention is not limited to this. That is, the present invention can be immediately used for comparable standards such as the CT2 standard and the GSM standard. The base station FT and the mobile station PT are the control unit CE and the radio unit or the transmitter / receiver RE-T / PE-R-within the important consideration of the present invention-there is no distinction between the base station FT and the mobile station PT. The peripheral circuit part PE is configured differently. That is, the peripheral circuit part PE in the base station FT is-a known cordless telephone system (Wolf, Klaus: "Auch ohne Schnur" auf Draht "", Telecom Report 10, 1987, Volume 2, page 100 and below, for example, No. 134. Starting from (page)-for example, the ADPCT coding / decoding device has an internal subscriber circuit or switch or PBX circuit and internal peripheral controller to which it is pre-connected, while the peripheral circuit part PE of the moving part PT. In-starting from the moving parts of known cordless telephone systems (Telcom Report 10, 1987, Volume 2, page 135)-eg microphones, piezoelectric earpieces, piezoelectric ring generators, storage batteries, keyboards, LED displays Includes a unit, as well as a low frequency and ring generator amplifier. The above-mentioned peripheral circuit unit PE of the base station FT and the mobile unit PT can be replaced by another circuit unit without limiting the present invention. The important parts of the circuit configuration of the base station FT and the mobile unit PT shown in FIG. 1 for the present invention are the radio part RE or the transmitter / receiver RE-T / RE-R and the control unit CE. At that time, two antennas A1 and A2 that function as a transmitting antenna and a receiving antenna are assigned to the radio portion RE for transmission and reception of a radio signal (for example, TDMA or CDMA radio signal). However, without limiting the present invention, one antenna or more than two antennas can be assigned to the radio unit RE. The radio unit RE further-as shown by the three functional blocks in Figure 1-transmitters (transsievers) T, R, electric field strength indicator (Radio Signal Strength Indicator) RSSI and interface equipment (Interface). They are connected to each other in the radio unit RE as shown in the figure. The electric field strength measuring device RSSI measures the electric field strength of the radio signal input via the antennas A1 and A2 and selected by the transmission / reception units T and R. The details of how the transmitter / receiver T and R are configured and how they are connected to the electric field strength measuring device RSSI and the interface device RE-I will be described with reference to FIG. The electric field strength measuring device RSSI is generally used to check whether a channel is occupied (DECT-Draft prETS 300 175-3: 1991, p. 164). The provisions on how electric field strength can be measured are given in the DECT standard (see DECT-Draft prETS 300 175-2: 1991, p. 31, 6.2 and p. 38, 8.3). At that time, the channel occupancy is detected by measuring the electric field strength (minimum electric field strength) of the received radio signal, and the measurement results RSSI1, ... Continue to be the main of the control unit CE via the AD converter A / D. It is supplied to the THVG, the threshold value generator integrated in the processor M-CT. At that time, the threshold generator THVG is incorporated into the controlling program by the main processor M-CT and used for controlling the antennas A1 and A2 in the continuous operation of the base station FT or the mobile unit PT. Form a value that is updated. For the information (input amount) regarding channel occupancy obtained by the threshold generator THVG, control data (Controlling DATA) CDATA is formed from the control program CP, and they are subprocessors (Sub) via the main processor interface M-CTI. -Controller) Supplied to S-CT. The subprocessor S-CT is referred to as a time switch controller in the base station FT and a burst mode controller in the mobile unit PT. Among other things, the subprocessor S-CT is assigned a multiplexing / multiplexing unit MUL / DEM that does not generate 1.152 Mbit / s data in the form of DECT burst format. Further, the subprocessor S-CT executes a control task for the radio unit RE and the peripheral circuit unit PE. In the base station FT, the multiplexing / multiplexing unit MUL / DEM of the subprocessor S-CT receives or should transmit data packets by time division multiple access (TDMA) or code division multiple access. In method CDMA (Code Division Multiple Acccess), for example, up to 6 internal telephone connections or up to 3 external telephone connections are assigned. In addition, the subprocessor S-CT includes a time control / counting device (timer / counter). location is particular bit, to the time slot and no TDMA respect temporal occurrence of CDMA frames subprocessor S-CT Timing control. FIG. 2 shows a detailed configuration of the radio unit RE with respect to the transmission / reception units T and R. The transmitter / receiver T, R includes functional blocks that are independent and dependent on the transmitter, transmitter SR, and receiver ER. The independent functional blocks are switched back and forth between the two selector elements pre-connected to the antennas A1 and A2, the selector switch (diversity switch) DS, and the transmitter DR and receiver ER in the above order. There is a selection switch (T / R switch) T / RS. The functional blocks of the transmitter / receiver T and R, which depend on each transmission device, are connected between the interface device RE-I of the radio unit RE and the selection switch T / RS in the above order in the transmitter SR. Between the two modules, the synthesizer / modulator SY / MO and the power amplifier PA, also referred to as the transmitter, and the electric field strength measuring device RSSI and the selection switch T / RS in the receiving device ER. Formed by the Receiver REC connected to. Except for the changeover switch DS, all the separate modules or functional blocks of the transmitter / receiver T, R are included in this transmitter / receiver even when, for example, only one antenna is assigned to the radio unit RE. The functions of cordless telecommunication in the cordless telecommunication system having the base station FT and the mobile part PT of Fig. 1 and Fig. 2 are described in the printed matter (Telcom Report 10, 1987, Volume 2, page 130 and below). It is shown in principle in DECT-Draft 175-3: 1991, entire record). That is, in the case of a bidirectional (transmitter / receiver or receiver / transmitter) wireless connection between the base station FT and the mobile unit PT in a cordless telecommunication system, voice is compressed and transmitted on the transmitting side on one side. And on the other hand it is received and on the receiving side it is stretched. Base station FT and mobile to reduce the energy costs required for base station FT and mobile PT, especially when the base station FT and mobile PT are constantly energized (eg by batteries or batteries). The transmitter RE-T of the unit PT is operated substantially only during the transmission time, and the base station FT and the receiver RE-R of the mobile unit PT are operated substantially only during the reception time (Fig. 4). Fig. 3 shows cordless telecommunication according to the DECT standard, as shown in West Germany Utility Model Registration No. 9214885 (Fig. 3) and No. 9214899 (Fig. 2). The DECT-specific TDMA time frame for the system is shown. Dynamic channel selection of approximately 120 available channels is performed for cordless telecommunication according to the DECT standard. 120 channels are 1.8 and 1. in the DECT standard. It arises from the use of 10 frequency bands between 9GHz, with 10ms time division multiplexing (TDMA) in each frequency band as shown in Figure 3. Operated by a frame. In this time division multiplexing frame, 24 (0 to 23) time division channels are defined, which predetermines the frame pattern. In that case, this frame pattern is such that for example 12 mobile PTs for each frequency band are duplicated at the same time as one base station in the DECT communication system (PT-FT and FT-PT or FT-PT and PT-FT). Used to be able to work. At that time, one time slot (Time Slot) of 417 μs is assigned to each of the 24 time division channels. At that time, this time slot indicates the time when information (data) is transmitted. This transmission of information in duplex operation is also referred to as the ping-pong method. The reason is that it is transmitted at a given time and received at another time. In this ping-pong scheme, in each time slot, 365 μs time frames or pulses (bursts), corresponding to a frame length of approximately 420 bits, are transmitted with a data throughput of 42 kbit / s. Considering that in relation to time division frames, 30 bits are used at each end of a time frame in a safe time frame (Guard Space = GS) to avoid overlap with adjacent time slots. A total data throughput of 1.152 Mbit / s is generated. Starting from the above description for FIG. 3, FIG. 4 has a transmit burst with a transmit time SZ and a receive burst EB with a receive time EZ after 5 ms (duplex operation) TDMA time frame (10 ms). ) Is illustrated. That is, for example, the mobile unit PT can transmit information to the base station FT during the transmission time SZ of the transmission burst SB and receive information from the base station FT during the reception time EZ of the reception burst EB (Case I). .. Alternatively, the base station FT transmits information to the mobile station PT during the transmission time SZ of the transmission burst SB and receives information from the mobile station PT during the reception time EZ of the reception burst EB. Can be (if II). The time order of the transmit burst SB and the receive burst EB is fixedly predetermined (5 ms) in the TDMA frame according to the DECT standard, and the transmit burst SB and the receive burst EB for the cordless operation of the base station FT and the mobile unit PT are Since this temporal relationship between is representing a temporal reference quantity, the base station FT and mobile PT are appropriately timed by the time control / counting device TI / CO in Figure 1 and are therefore DECT specific. It is adjusted to the time frame of. Therefore, for example, when the user of the mobile unit PT tries to transmit information (for example, voice communication) to the base station FT in the TDMA frame, the mobile unit PT transmits at the UESP at the transmission start time (the beginning of the transmission burst SB having the transmission time SZ). Must be ready. Preparation for transmission means that the radio unit RE, the control unit CE, and the peripheral circuit unit PE of the mobile unit PT in FIG. 1 are switched on. This can be achieved, for example, by ensuring that the circuit unit is switched on for the entire duration of the mobile unit PT being activated by the user. However, for this reason, on the other side, the energy supply source (eg battery or storage battery) of the mobile unit PT is loaded more strongly (in the sense of energy consumption), and therefore the effect of the mobile unit PT until battery replacement or charging of the storage battery. The operating time will be reduced. In order to at least partially consider the above two requirements in the mobile unit PT, the transmitter / receiver RE / T and RE / R are substantially operated only during the transmission time SZ of the transmission burst SB. For this operation, the transmitter / receiver RE / T, RE / R are switched on by the first early time tv1 with respect to the UESP at the time of transmission. Due to this first early time tv1, the transmitter / receiver RE / T, RE / R needs some start time to be fully functional (start phase). At that time, the first early or read (advance) time tv1 is selected so that the start phase of the transmitter / receiver RE / T and RE / R ends at the UESP at the transmission start point. However, in case the start phase of the transmitter / receiver RE / T and RE / R may not have ended at the start of transmission (for example, due to the aging of electronic elements in the moving part PT), the second early time It is advantageous to provide tv2. This second early time tv2 guarantees that the transmitter / receiver RE / T, RE / R are ready to operate at the time of transmission UESP in any case (the start phase has ended in each case). To. Therefore, the switch-in time of the transmitter / receiver RE / T and RE / R required for information transmission of the mobile unit PT is determined by the first early time tv1, the second early time tv2, or the entire early time tv1 + tv2. You can decide. In FIG. 4, as described above, the transmitter / receiver RE / T and RE / R are on one side, and the electric power strength measuring device RSSI and the interface device, which are hereinafter referred to as the central functional elements of the transmitter / receiver RE / T and RE / R, are used. It consists of RE-I, selector switch DS, selector T / RS and power amplifier PA and transmitter SY / MO and receiver REC on the other, starting from being switched on at the same time at any possible switch-on time. ing. Alternatively, however, the central functional elements of the transmitter / receiver RE / T, RE / R can be switched on with time lag with respect to the transmitter SY / MO and receiver REC. Furthermore, it is conceivable to extend the switch-on related to the transmission time of the mobile unit PT to all the functional circuit units of the mobile unit PT, which are not necessary for monitoring the TDMA frame clock. Further, similar to the second early time tv2, a delay time tn2 that cuts off the transmitter / receiver RE / T and RE / R at the end of transmission transmission (the end of the transmission time SZ of the transmission burst SB) can be set. As a result, the transmitter / receiver RE / T and RE / R can be prevented from being shut off significantly earlier if a time drift or frequency drift occurs in the time controller TI / counter CO. The description so far regarding the transmission burst SB having the transmission time SZ also applies to the reception burst EB having the reception time EZ in which the mobile unit PT obtains information (for example, voice communication) from the base station FT. Further, the above description (Case I) for the transmission / reception operation of the moving unit PT in the TDMA frame also applies to the transmission / reception operation (Case II) of the base station FT in the TDMA frame of FIG.