RU2113766C1 - Receiver of base station of radio communication system using code channel separation - Google Patents

Abstract

FIELD: communication. SUBSTANCE: device has n receivers 1 which outputs are connected to inputs of level analyzers 9 which outputs are connected to inputs of control unit 6. Outputs of control unit 6 are connected to inputs of first and second commutators 5 and 7. Second outputs of receivers 1 are connected to inputs of n reference signal generators 4 which outputs are connected to inputs of second commutator 7. Outputs of commutator 7 are connected to inputs of k adders 110, which outputs are connected to inputs of rejection units 3. Outputs of k rejection units 3 through k interface units 2 are connected to left inputs of first commutator 5, which right inputs are connected to outputs of first interface unit 8 which one output is connected to input of first rejection unit 3.1. Outputs of commutator 5 are connected to inputs of n receivers 1. EFFECT: decreased need in regulation of output power of antenna transmitters, increased output capacity of system or decreased requirements to number of power levels and precision of their setting. 1 dwg

Description

 The invention relates to the field of radio communications and may find application in communication systems with code division multiplexing.

 Known receiving equipment of the central station (CA) asynchronous address communication system (AACC) "Kolos", described in the monograph Pyshkin IM and other mobile radio communication systems. -M .: Radio and communications 1986, p. 101, containing n receivers connected to the antenna through blocks and antenna distributors, the disadvantage of which is resistance to structural interference when used in an asynchronous communication system with wideband signals.

 A well-known system with multiple access and code division multiplexing, designed by Qualcomm and described in "Justification of the applicability of code division multiple access (SDMA) for digital cellular systems to personal cellular networks" (USA, Qualcomm, May, 1992), in which the CA contains n receivers receiving signals from n mobile subscriber stations (AS). The level of structural noise on the CA in this system is reduced through the use of adaptive power adjustment of the AC signals.

 The disadvantage of this system is the reduction in the throughput system due to the need for the exchange of service commands between the CA and AC for power control, as well as stringent requirements for the accuracy of power control.

 Closest to the technical nature of the proposed is the receiving equipment of the base station AACC "Keychain-1", described in the technical description "Complex communications equipment" Keychain-1 ", Voronezh, 1979.

The block diagram of the prototype is shown in FIG. 1, where it is indicated: 1 ₁ - 1 _n - receiving devices, 2 - matching device, 3 - signal level analyzer.

 The CS receiving equipment contains a matching device 2, the input of which is the input of the device, and its n outputs are connected to the inputs of n receivers 1, the information outputs of which are the outputs of the equipment, other outputs of the receivers 1 are connected to n inputs of the signal level analyzer 3, the output of which is the output of the equipment .

 The input mixture is fed through a matching device 2 to the inputs of n receivers 1. In each of the n receivers 1, the signal received from one of the subscriber stations (AS) is processed. From the outputs of n receivers 1, the signals are fed to the analyzer of the levels of received signals 3. In the analyzer of levels 3, the levels of the received signals are measured and a decision is made about which of the received signals have an unacceptable interfering effect on the reception of weaker signals from remote speakers. This information is brought to the transmitter of the CA, which brings it to the appropriate speakers, in which the power of the transmitters is reduced. The other outputs of the receivers 1 are information outputs.

 The disadvantages of the prototype are the reduction in system capacity due to the need for transmission of service signals, strict requirements for the accuracy of adjusting the power of the AC signals, the inertia of the system, as well as the presence of restrictions on the minimum allowable distance between the AC and the CA, due to the finite number of gradations of the power of the AC transmitters.

 To eliminate this drawback, a device containing n receivers, a matching device, a level analyzer, the inputs of which are connected to the first outputs of the receivers, are introduced k blocks of notch wideband signals, n blocks of reference signals, the first and second switches, control unit, k matching devices, k adders, the inputs of the receivers connected to the n outputs of the first switch, the second outputs of the receivers through the corresponding blocks of the reference signals connected to the inputs of the second switch, the group of outputs of which are connected are connected to the inputs of k adders, the output of each adder through the corresponding notch block is connected to the input of the corresponding matching device, n outputs of each of (k + 1) matching devices are connected to the inputs of the first switch, the outputs of the level analyzer are connected to the inputs of the control unit, one group of outputs of which connected to the inputs of the first switch, and another group of outputs connected to the inputs of the second switch. One of the outputs of the first matching device is connected to the first rejection unit.

 The structural diagram of the proposed equipment is presented in FIG. 2, where it is indicated: 1 - receivers, 2 - matching devices, 3 - block of rejection of broadband signals, 4 - block of reference signals, 5, 7 - switches, 6 - control unit, 8 - first matching device, 9 - level analyzer, 10 - adders.

 The equipment contains n receivers 1, some outputs of which are connected to the inputs of the level analyzer 9, others - to the inputs of the reference signal blocks 4, the outputs of which are connected to the inputs of the switch 7. The inputs of the receivers 1 are connected to the inputs of the switch 5. The outputs of the level analyzer 9 are connected to the inputs of the block control 6, one group of outputs of which is connected to the outputs of the switch 5, the other with the inputs of the switch 7. The outputs of the switch 7 are connected to the inputs k of the adders 10, the outputs of which are connected to the inputs of the corresponding k blocks of notch 3. Outputs k Notch blocks 3 are connected to inputs of k matching devices 2. And all n outputs of each of matching devices 2 and 8 are connected to inputs of switch 5.

 The equipment operates as follows.

 In an asynchronous-address communication system, all speakers use broadband phase-shifted signals occupying a common frequency band and operating on the same carrier frequency. Address feature of the speaker is the structure of the SRP.

In the initial mode of operation, when none of the CA receivers entered synchronism with the AC transmitter, the input mixture through the matching device 8 enters the first n inputs of switch 5 (inputs 1 ₁ ... 1 _n ), which connects them to the inputs of the corresponding receivers 1. Each of the receivers 1 generates a synchronization signal (SS), indicating its entry into synchronism with its transmitter AC. The synchronization signal (CC) is supplied to the control unit 6. In addition, one of the signals of each receiver 1 is fed to a level analyzer 9, where a decision is made on how strong is the interfering effect of the signal received by this receiver 1 on the reception of signals from other speakers .

 In the event that the level of one or more received signals (from near speakers) is so high that it does not allow synchronization of receiver 1 with other speakers farther away from the CA, in the CA equipment, powerful interfering signals are cut at the inputs of other receivers 1.

If we assume that the speakers are evenly distributed over the area around the central speaker, then it is obvious that the receivers 1 with the closest located to the central speaker (first group speakers) will enter into synchronism. At the same time, receivers receiving signals whose powers differ slightly from each other (P _max / P _min << B, B - ShPS base) can synchronize simultaneously. Since the signals from closely spaced speakers interfere with others that are more distant from the central speaker, the signals of the first group are rejected at the inputs of other receivers 1 in the notch block 3 ₁ .

After the synchronization of the first group of speakers, it is possible to enter the synchronism of the second group of speakers, which are located in the second (more remote) zone relative to the CA. However, the signals of the second group can also interfere with more distant other speakers and they must be cut off at the inputs of other receivers 1. To ensure that speakers are synchronized sequentially by groups with subsequent notching of signals from a group with more powerful signals at the inputs of other receivers 1, it is set in level analyzer 9 several (k) thresholds. If the first threshold (highest) P _{1 is} exceeded, then the receivers 1, whose signals exceeded it, remain connected to the first inputs (1 ₁ ... 1 _n ) of switch 5, i.e. to the outputs of the matching device 8. All other receivers 1 are connected to the second inputs (2 ₁ ... 2 _n ) of the switch 5. In this case, the signals received at the inputs of the receivers connected to the second inputs of the switch 5 pass through the matching device 8, block notches 3 ₁ and matching device 2 ₁ , i.e. at the inputs of these receivers 1 are rejected powerful signals of the first group of speakers, exceeding the threshold P ₁ .

The receivers 1 whose signals exceeded the second threshold P ₂ (P ₂ <P ₁ ) remain connected to the second inputs of the switch 5, and the remaining receivers are connected to the third (3 ₁ ... 3 _n ) inputs of the switch 5, i.e. to the outputs of the matching device 2 ₂ . To these receivers, the input mixture arrives after notching from them the powerful signals of the first AS group, which exceeded the threshold P ₁ , and the signals of the second AC group, which exceeded the threshold P ₂ .

 The system can provide for the rejection of signals of k groups. In this case, k series-connected notch blocks and matching devices should be used.

Signal rejection in the notch blocks 3 is carried out using reference signals generated in the block of reference signals 4 using signals supplied from the respective receivers. The reference signals generated in the blocks of the reference signals 4 are supplied to the notch blocks 3 ₁ ... 3 _k through the switch 7 and the corresponding adders 10 ₁ ... 10 _k . The control of the switches 7 and 5 is carried out by the control unit 6. The formation of commands in the control unit 6 is carried out using information about the levels of received signals (information about exceeding or not exceeding the thresholds P ₁ , P ₂ , ... P _k ) received from the analyzer of levels 9, and synchronization signals (SS) coming from the outputs of the receivers 1.

Thus, the proposed equipment provides the elimination of the interfering effect of high-power broadband radios from speakers located close to the CA on the operation of the CA receivers receiving signals from remote speakers. This is achieved due to the fact that for receivers working with remote speakers, the input mixture is fed after notching from it powerful signals from nearby speakers. In the DS equipment, simultaneous synchronization of receivers receiving signals close in level is ensured, for which the condition P _max / P _min <B is satisfied, where P _max and P _min are the maximum and minimum power of the signals in this group.

 By changing the number of thresholds and their levels in the level analyzer 9 and the corresponding change in the number of notch blocks, it is possible to reduce the level of mutual interference to an acceptable value.

 When using the proposed equipment, either the need to use power control is removed (in this case, the system capacity increases due to the exclusion of power control service commands from the stream of transmitted messages), or the requirements for the number of gradations and the accuracy of setting the power of the AC transmitters are reduced, which simplifies the hardware implementation transmitters and increase system bandwidth.

 The notion of the power of the BSS from the near speakers removes the restrictions on the minimum allowable distances between the DS and the speakers that occur in the prototype (due to the finite number of power gradations). The latter circumstance increases the operational and tactical capabilities of the system.

 Consider the hardware implementation of the blocks included in the proposed equipment.

For ease of understanding, consider the case of using two thresholds P ₁ and P ₂ in the level analyzer 9, P ₁ > P ₂ , which corresponds to the use of two notch blocks 3 ₁ and 3 ₂ and the division of subscribers into three groups. The signals of the speakers of the first group exceed the threshold P ₁ , the signals of the second group of speakers exceed the threshold P ₂ . The signals of the speakers of the third group are received from more distant speakers and exceed neither P ₁ nor P ₂ .

 We assume that the receivers of the device are built according to the standard scheme (for example, as shown in ed. St. N 300946, class H 03 C 3/40, 1971). This circuit is shown in FIG. 8, where it is indicated: 81 - synchronization device, 82, 86 - multipliers (recirculators), 83 - orthogonal PSP driver, 84 - phasing device, 85 - reference PSP generator, 87, 89 - bandpass filters, 88 - phase detector.

 In this embodiment, the receivers synchronization signal (SS) is generated by the synchronization device 81. The output "SS" is the output of block 81 connected to the inputs of the generators SRP 83 and 85. The outputs of the receivers 1, from which the signals are supplied to the blocks of the reference signals 4, are the outputs of blocks 83 and 85, forming the SRP synchro- and information channels. The output of the receiver 1, from which the signals are supplied to the level analyzer 9, may be the output of the filter 87 (or 89), because these outputs make it possible to measure the level of "rolled up" ShPS.

In this case, the level analyzer 9 can be made in the form of n independent rulers, each of which is connected to one of n receivers and is a series-connected detector and two threshold comparison schemes. Moreover, in the first comparison scheme with the threshold, the detected signal of the receiver is compared with the threshold P ₁ , in the second - with the threshold P ₂ . Thus, two commands are generated at the output of the level analyzer: PP ₁ (about exceeding the threshold P ₁ ) and PP ₂ (about exceeding the threshold P ₂ <P ₁ ).

 The block diagram of the notch unit 3 is shown in FIG. 3, where it is indicated: 31 - multiplier (modulator), 32 - notch filter, 33 - multiplier (remodulator), 34 - band-pass filter tuned to the carrier SHPS and having a passband equal to the bandwidth of the transmitted SHPS, 35 - adjustable delay element (used if necessary).

Let us explain the work of notching by the example of the operation of block 3 ₁ . The input mixture appears to the input of the notch block 3 ₁ from the output of the matching device 8. The second input of block 31 is supplied with a reference signal from the output of adder 10 ₁ , which is either a reference signal generated by one of the receivers, or the sum of the reference signals generated by several receivers, the received signals of which exceeded the threshold P ₁ . The reference signal from the second input is supplied to the multiplier 31 directly, and to 33 through the delay element 35.

 Note that the reference signals arriving at block 3 are synchronous with the corresponding SHPS in the input mixture.

The “folded” signals are rejected in block 32 and, therefore, do not pass to the output of the block. At the same time, SHPS from other speakers, whose reference signals did not arrive at the notch block, pass to block 33, because in block 31, additional manipulation is imposed on them according to the law of the supplied reference signals, and in block 33 it is removed by multiplying with the same reference signals. The input mixture, from which the ShPS of those speakers are excluded, the received signals of which exceeded the threshold P ₁ through a bandpass filter 34 tuned to the ShSS carrier common to all speakers with a passband equal to the ShPS band, is fed to the output of the notch block 3. Delay element 35 is used when the need to align the signals in time to ensure synchronization of the input signals in block 33. As multipliers 31 and 33, various types of balanced modulators can be used (see GI Tuzov, Statistical Theory of Receiving Complex Signals. M .: Ra Dio and Communication, 1977, p. 51). Note that the term "multiplier" as applied to the terminology of ShPS means imposition and removal, manipulation according to the law of the SRP (see the mentioned monograph by G. Tuzov).

The block diagram of the reference signal block is shown in FIG. 4, where it is indicated: 41 - the oscillator frequency generator, 42, 43 - multipliers (phase manipulators), 44 - adder, 45, 46 - delay elements, 47 - phase shifter 90 ^o .

The block of reference signals 4 is a shaper shpc at the local oscillator frequency. Delay elements 45, 46 are introduced to ensure the synchronism of the generated reference signals with the input SHPS taking into account possible signal delays in the equipment paths. These elements are and are used when necessary. The reference receiver SRP through the delay elements 45, 46 is fed to the multipliers 42, 43 (phase manipulators), where they phase-manipulate (at 0, 180 ^o ) the local oscillator signal generated in block 41 in the in-phase and quadrature channels, which are summed in block 44.

 The block diagram of the control unit 6 (for the case of using two notch blocks 3) is shown in FIG. 6, where it is indicated: 6-1 — device for generating control commands for switches, 61 — keys, 62 — OR circuit, 63 — adders modulo two, 64 — keys, 65 — keys, 66 — inverters.

 The control unit 6 contains two identical devices 6-1, providing the formation of control commands of the switches 5 and 7, as well as inverters 66 and keys 64, 65.

The inputs of block 6 from the outputs of receiver 1 receive the following commands: synchronization signal - SS, exceeding the threshold П ₁ - ПП ₁ and exceeding the threshold П ₂ - ПП ₂ .

The SS and PP ₁ commands are sent to the inputs of the first device 6-1, and the SS and PP ₂ signals are input to the inputs of the second device 6-1 through the keys 64 and 65, controlled by the PP ₁ command inverted in block 66.

 The control unit 6 operates as follows.

Сигналы с выходов ключей 61 второго устройства 6-1 являются командами подключения блоков 4 к сумматору 10₂

Команды с выходов ключей 61 подаются на первые входы сумматоров по модулю два 63, на вторые входы которых подается команда с выхода схемы ИЛИ 62. Допустим, что все команды СС и ПП принимают значение "0", что соответствует случаю отсутствия синхронизации и превышения порога в n приемниках ЦС. Тогда на входах ключей 61 присутствуют нули и на выходах ключей 61 формируется "0", на выходе схемы ИЛИ 62 и выходе сумматора по модулю два 63 также формируется "0". С выходов сумматоров по модулю два 63 сигналы подаются на входы блока 5 и являются командами управления коммутатора 5 (КУК). Если КУК принимает значение "0", выходы коммутатора 5 подключаются к его правым входам. Если КУК принимает значение "1", выходы блока 5 подключаются к его левым входам.On each of the keys 61 is supplied SS command indicating occurrence of the receiver in synchronism with its speaker, and the command PP, indicating excess ( "1") or of not exceeding ( "0") level of the received data receiver set threshold signal P _1. The CC command is control if the CC takes the value "1", key 61 skips the PP command to its output, otherwise the PP command does not pass, i.e. at the output of the key 61 there is a "0". The signals from the outputs of the keys 61 of the first device 6-1 are commands for connecting blocks 4 to the adder 10 ₁

The signals from the outputs of the keys 61 of the second device 6-1 are commands for connecting blocks 4 to the adder 10 ₂

Commands from the outputs of the keys 61 are fed to the first inputs of the adders modulo two 63, to the second inputs of which a command is issued from the output of the OR circuit 62. Suppose that all the SS and PP commands take the value "0", which corresponds to the case of lack of synchronization and exceeding the threshold in n CA receivers. Then, at the inputs of the keys 61, zeros are present and "0" is formed at the outputs of the keys 61, "0" is also formed at the output of the OR circuit 62 and the output of the adder modulo two 63. From the outputs of the adders modulo two 63 signals are fed to the inputs of block 5 and are control commands of the switch 5 (CCC). If the CUC takes the value "0", the outputs of the switch 5 are connected to its right inputs. If the CUC takes the value "1", the outputs of block 5 are connected to its left inputs.

 Thus, in the situation considered, corresponding to the initial mode of operation, all receivers are connected to the right inputs of block 5, i.e. to the matching device 8.

 Consider the situation of the appearance of “1” at the two inputs of one of the keys 61, “1” is formed at its output, “1” at the output of the OR circuit 62, and “0” remains at the output of the block 63 corresponding to this key those. the receiver in question, which generated these commands, remains connected to the right inputs of the switch 5, and through it to the matching device 8.

However, if simultaneously with the presence of "1" at the outputs of one or more blocks 61 at the outputs of other (one or more) blocks 61, there is "0", then at the outputs of the adders modulo two 63, corresponding to these other keys 61, "1" will be formed and the receivers that generated the SS and PP commands for these other keys will be connected to the left inputs of switch 5, i.e. to the matching device 2 ₁ .

Indeed, if at the output of at least one block 61 a "1" is formed, then at the output of the block 62 it will also be "1", then "1" is formed at the outputs of the block 63 connected to blocks 61 with "zeros" at their outputs. which provides the connection of the respective receivers 1 to the left outputs of block 5. The CC and PP ₁ commands are sent to the inputs of the first (left) device 6-1, and the CC and PP ₂ commands are sent to the inputs of the second (right) device 6-1 (provided that they do not exceed threshold P ₁ in the respective receivers 1). At the output of the first unit 6-1 generates a command KUK1 KUK1 ₁ ... _n, providing connections to the outputs of the receivers 8 matching device (switch inputs 5 1 _1... 1 _n) of the matching device 2 or ₁ (ports 2 ₁ ..2 _n switch 5). At the output of the second (right) device (6-1), the commands KUK2 ₁ ... KUK2 _n are generated, providing the connection of the corresponding receivers 1 either to the outputs of the matching device 2 ₁ (inputs 2 ₁ ... 2 _n ), or to the outputs of the matching device 2 ₂ (inputs 3 ₁ ... 3 _{n of} switch 5). Note that if the software ₁ takes the value "1", then at the output of the right device 6-1, the KUK and KP10 commands take the value "0", because keys 64 and 65 are closed.

Thus, block 6-1 generates commands for those receivers for which the threshold P ₁ is not exceeded. This means that receivers 1, which did not enter synchronism in the presence of synchronization of other DS receivers with powerful signals (exceeding threshold P ₁ ), will be connected through notching device 8 to notch block 3 ₁ , where powerful BSSs from closely spaced speakers are cut from the input mixture.

Receivers that are not synchronized (if there are synchronization of other receivers whose signals have exceeded the thresholds P ₁ and P ₂ ) will be connected to block 3 ₂ , where those BSSs that ensure that the threshold P _{2 is} exceeded will be cut from the input signal. Thus, at the output of block 3 ₂ , powerful SHPS are cut out, which exceeded the thresholds P ₁ and P ₂ .

 The block diagram of the switch 5 is shown in FIG. 5, where it is indicated: 51, 52 - 1 x 2 switches.

The inputs of the switch 5 receive signals from the outputs of the matching device 8 (inputs 1 ₁ ... 1 _n ), from the outputs of the matching device 2 ₁ (inputs 2 ₁ ... 2 _n ) and from the outputs of the matching device 2 ₂ (inputs 3 ₁ . ..3 _n ). The inputs of block 5 are switched to the outputs connected to the receivers 1 ₁ ... 1 _n .

 Switches 51 are controlled by KUK1 commands, and switches 52 are controlled by KUK2. When a command “0” is supplied to the control inputs of the switches 51 and 52, the output of the switch 5 is connected to its right inputs, when a “1” is supplied, to the left.

If KUK2 takes the value "0", then the switches 52 ₁ ... 52 _n connect the inputs of the respective receivers to the inputs 2 ₁ ... 2 _{n of the} switch 5 and in this case the control is carried out by the switch 51. Moreover, if KUK1 takes the value "0" , then the corresponding receivers are connected to the inputs 1 ₁ ... 1 _n . If KUK1 takes the value "1", then the corresponding receivers are connected to the inputs 2 ₁ ... 2 _n .

If KUK2 takes the value "1", then the corresponding receivers are connected to the inputs 3 ₁ ... 3 _n . In this case, depending on the value of KUK1 "0" or "1", the corresponding receivers are connected to the inputs 1 ₁ ... 1 _n or 2 ₁ ... 2 _n .

The structural diagram of the switch 7 for the case of using two blocks of notch 3 ₁ and 3 ₂ shown in Fig.7, where 71 ₁ , 71 ₂ - keys.

а на второй вход второго ключа - команда

Выходы ключей 71₁₁...71_1n соединены с входами сумматора 10₁, выходы ключей 71₂₁...71_2n - с входами сумматора 10₂. Команды

и

принимают значения "0" или "1", что соответствует закрытию или открытию соответствующего ключа. Если превышен порог П₁, то KП10 $\genfrac{}{}{0ex}{}{\text{i}}{\text{1}}$ принимает значение "1", при этом открывается первый ключ 71_1i и i-й блок 4 подсоединяется к i-му входу блока 10₁.The switch 7 contains two key pairs 71 ₁ and 71 ₂ , the first inputs of which are combined. A general view of each key pair is connected to the output of one of the reference signal conditioners 4. In each key pair, a command is sent to the second input of one of the keys

and on the second input of the second key - a command

The outputs of the keys 71 ₁₁ ... 71 _{1n are} connected to the inputs of the adder 10 ₁ , the outputs of the keys 71 ₂₁ ... 71 _2n are connected to the inputs of the adder 10 ₂ . Teams

and

take the values "0" or "1", which corresponds to closing or opening the corresponding key. If the threshold P _{1 is} exceeded, then KP10 $\genfrac{}{}{0ex}{}{\text{i}}{\text{1}}$ takes the value "1", the first key 71 _1i is opened and the i-th block 4 is connected to the i-th input of the block 10 ₁ .

принимает значение "1", при этом ключ

открывается и подключает μ -тый формирователь опорного сигнала 4 ко входу сумматора 10₂.If threshold П _{2 is} exceeded (provided that threshold П ₁ is not exceeded), then KP10 $\genfrac{}{}{0ex}{}{\text{i}}{\text{1}}$ has the value "0" (the key 71 _1i is closed in this case), and

takes the value "1", while the key

opens and connects the μ-th driver of the reference signal 4 to the input of the adder 10 ₂ .

Therefore, the reference signal conditioners 4 of those receivers 1 in which the threshold P ₁ is exceeded through the adder 10 _{1 are} connected to the notch block 3 ₁ , and the blocks 4 of those receivers 1 in which the threshold P ₂ is exceeded (if the threshold P _{1 is} not exceeded) are connected through the adder 10 ₂ to notch block 3 ₂ .

Adders 10 ₁ and 10 ₂ provide a combination of n inputs on one adder and can be performed, for example, using terminating resistors. Matching device 8 provides the supply of the total signal from the output of the antenna or from the output of the notch block to the inputs of n receivers and can be made in the form of matching resistors.

Claims (1)

 The receiving equipment of the base station of the radio communication system with code division multiplexing, containing n receivers, an analyzer of the levels of the received signal, the inputs of which are connected to the outputs of the receivers, the first splitter, characterized in that the first and second switches, a control unit, n shapers of the reference signal, k adders , k blocks of rejection of powerful broadband signals, k splitters, n outputs of the first, second, ..., (k + 1) -th splitters are connected respectively to the first, second, .., (k + 1) -th input groups of the first com a tripod, the outputs of which are connected to the inputs of n receivers, the second outputs of which are connected to the inputs of the corresponding shapers of the reference signals, the outputs of which are connected to the inputs of the second switch, the outputs of the second switch are connected to the inputs of k adders, the outputs of which are connected to the inputs of k blocks of rejection of powerful broadband signals, the outputs of which are connected to the inputs of the respective splitters, one of the outputs of the first splitter is connected to the second input of the first block of rejection of powerful broadband signals, Moreover, the outputs of the analyzer of the levels of the received signal are connected to the inputs of the control unit, the outputs of which are connected to the inputs of the first and second switches.

Images