RU2105417C1 - Base station receiver for communication network which use code channel share - Google Patents

Abstract

FIELD: radio communication systems, in particular, asynchronous address communication networks using wide-band signals. SUBSTANCE: device has serial circuit of interface unit 2, heavy wide-band signals rejection unit 3, interface unit 4, which n inputs are connected to corresponding inputs of commutator 5 which outputs are connected to inputs of corresponding n receivers 1.1..., 1.n. One output of each receiver is connected to corresponding input of signal level analyzer 7. Other inputs of receivers serve as device outputs. Other outputs of all receivers are connected to corresponding inputs of rejection unit 3. Additional outputs of each receiver are connected to corresponding inputs of control unit 6, one of which inputs is connected to output of signal level analyzer 7. Its corresponding outputs are connected to inputs of commutator 5 and rejection unit 3. EFFECT: increased functional capabilities. 7 dwg

Description

 The present invention relates to the field of radio communications and may find application in asynchronous-address communication systems with broadband signals.

 Known receiving equipment of the central station (CA) asynchronous address communication system (AACC) "Kolos", described in the monograph "Systems of mobile radio communications" IM Pyshkin and others, M .: Radio and communication, 1986, p. 101, comprising n receivers connected to the antenna through bridge units and antenna distributors. The disadvantage of this communication system is its low resistance to structural interference.

 A well-known communication system with multiple access and code division multiplexing, designed by Qualcomm, is given in "Justification of the applicability of multiple access codes with code division (SDMA) in relation to digital cellular systems and personal cellular networks" (USA, Qualcomm, May, 1992).

 In this system, the CA contains n receivers, each of which receives signals from its mobile subscriber station (AS).

 The level of mutual structural interference 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 bandwidth due to the need for the exchange of service commands between the CA and the AC in the process of adjusting the power of the AC, as well as stringent requirements for the accuracy of the power setting.

 The closest in technical essence to the proposed one is the receiving equipment of the CA AACC "Keychain-1", described in the description "The complex of communications equipment" Keychain-1. Technical description ". Voronezh, 1979.

The structural diagram of the prototype is shown in figure 1, where it is indicated: I ₁ ... I _n - receiving device (PFP); 2 - matching device (SU); 3 - signal level analyzer.

The receiving equipment contains a matching device 2, the input of which is the inputs of the entire device, and n outputs are connected to the corresponding inputs of the PFP (I ₁ ... I _n ), the information outputs of which are the outputs of the equipment.

 Other PRM outputs are connected to the corresponding inputs of signal level analyzer 3.

 The prototype works as follows.

 The input mixture through SU2 is fed to the inputs of n receivers. In each PFP, the signal processing of one of the subscriber stations (AS) is carried out. The signals from n receivers are fed to the inputs of signal level analyzer 3, where 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 fed to the transmitter of the CA, which brings it to the appropriate speakers. In the AC, these commands reduce the power of the transmitters.

 The disadvantage of the prototype device is the low throughput of the system, due to the need to transmit service signals, the inertia of the system, strict requirements for the accuracy of adjusting the power of the AC signals, 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.

 These disadvantages are eliminated due to the fact that n receiving devices (POS), n receiving devices (PFP), the outputs of which are connected to the corresponding inputs of a signal level analyzer (AUS), and other outputs and PFP are outputs of the entire device, are introduced serially connected block of rejection of powerful broadband signals (BR), an additional control system, a switch, n outputs of which are connected to the corresponding inputs of n PRM, the outputs of which are connected to the corresponding inputs of the BR, other outputs and PRM with are united with the respective control unit (CU) inputs, the outputs of which are connected with one of the switch inputs and BR, and BU input to one connected to the output ADR. In this case, the corresponding outputs of the control system are connected to the input of the BR and to the n inputs of the switch.

The structural diagram of the claimed equipment is presented in figure 2, where it is indicated: I ₁ . ..I _n - receiving devices (PFP); 2, 4 - the first and second matching device (SU), 3 - block rejection of powerful broadband signals (BR), 5 - switch, 6 - control unit (BU), 7 - signal level analyzer (ACS).

The proposed equipment contains a series-connected first SU 2, BR 3, the second SU 4, n outputs of which are connected to the corresponding inputs of the switch 5, the outputs of which are connected to the inputs of the corresponding PFP I ₁ . . .I _n . One of the outputs of each PFP is connected to the corresponding input of the AUS 7, and the other outputs of each PFP I ₁ ... I _n are the outputs of the entire device.

Other outputs of the PFP I ₁ ... I _{n are} connected to the corresponding inputs of the BR Z. Another outputs of each PFP I ₁ ... I _{n are} connected to the corresponding inputs of the control unit (CU) 6, one of the inputs of which is connected to the output of the AUS 7, and the corresponding outputs to the inputs of the switch 5 and BR Z.

 The inventive equipment operates as follows.

 In AASC, all subscriber stations use broadband phase-shift keyed signals (SHPS), which occupy a common frequency band and operate 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 containing the BSS from n AC through CS 2 is fed to the corresponding inputs of switch 5, which feeds them to the inputs of the corresponding PFP I ₁ ... I _n

Each of the PFP I ₁ ... I _n generates a synchronization signal (CC), indicating its entry into synchronism with its own AC, which is fed to the control unit (CU) 6.

 The signal from each PFP is fed to the corresponding input of AUS 7, where a decision is made on how strong the interfering effect of the signal received by this PFP is on the reception of signals from other speakers.

 In the event that the level of signals received from the near speakers is so high that it does not allow the receivers to enter synchronism with other remote speakers, the notch of a detected powerful interfering signal at the inputs of other PFPs is performed in the CA equipment. The control unit 6 receives synchronization signals (SS) from the PFP, as well as information about the signal levels in the PF from the output of the AUS 7. The control unit 6 controls the switch 5.

 The control algorithm implemented by block 6 is as follows.

 If the measured signal level exceeds the permissible value in at least one PfP, which is included in the synchronism, the inputs of all other receivers are connected via the SU 5 to the BR 3 output through the SU 4. In this case, the input mixture will come to the PFP connected to the outputs of the SU 4 from which powerful interfering signals from closely spaced speakers are excluded.

 Powerful signals from closely spaced speakers arrive at the appropriate receivers from the control system outputs And through the switch 5. High-frequency splitters are cut into the BR Z using reference signals from the corresponding PFPs, the use of which provides the “convolution” of powerful split-bandwidths into narrow-band signals on a common carrier or intermediate frequency followed by filtering them in a notch filter. At the same time, in BR 3, the passage of SHPS from more distant speakers is ensured.

 T. about. the equipment provides the passage of powerful BSS to the corresponding PFP through the control system 2, BR З and switch 5, and weaker BSS go to the inputs of the corresponding PFP through the control system 2, BR 3 and switch 5.

 Due to the use of BR Z, the influence of powerful signals from closely spaced speakers on the operation of the PFM, receiving signals from more distant speakers, is mitigated.

 The hardware implementation of the introduced blocks is as follows.

The structural diagram of the switch and is presented in figure 5, where it is indicated: 5 ₁ ... 5 _1n - _{1 × 2} switches
Block 5 contains n switches 1 × 2, 2n strong inputs and n control inputs, with n right inputs (n _p ) connected to n outputs of SS 2, n left inputs (n _l ) with n outputs of SS 4, and n control inputs with outputs of control unit 6.

 Each of the switches 51 is connected to one left and one right signal inputs and one control input.

 The switch 51 operates as follows.

 If there is a command "0" at the control input of block 51, its output is connected to its right input. When the command "1" on the control input appears, the output of block 51 switches to its left input.

 Command "1" corresponds to the case of synchronization of one or more receivers with powerful signals, the levels of which exceed the permissible value, from the nearest speakers, provided that there are other non-synchronized receivers on the CA.

In this case, the inputs of non-synchronized receivers are connected to the left inputs of the switch, and the inputs of the PfP, which are synchronized and have a large input signal level, are connected to the right inputs of the switch
The structural diagram of the control unit 6 is shown in Fig.6, where it is indicated: 61 ₁ ... 61 _n - keys, 62 - OR circuit, 63 ₁ ... 63 _n - adders modulo 2.

Block 6 contains n keys 61 ₁ ... 61 _n , the outputs of which are connected to the corresponding inputs of the OR circuit 62 and at the same time to the corresponding inputs of the adders 63 ₁ ... 63 _n . The output of the OR circuit 62 is connected to the corresponding inputs of the adders 63 ₁ ... 63 _n , the outputs of which are connected to the corresponding inputs of the switch 5.

 BU 6 works as follows.

For each key 61 ₁ ... 61 _n , a “PP” command is issued from the output of AUS 7 about exceeding “1” or not exceeding “0” by the level of the received signal of the set threshold and the command “CC” (synchronization signal), indicating the entry of this receiver into synchronism with the corresponding AC signal.

 The “CC” command is control if the “CC” has a value of “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 commands "0" or "1" from the outputs of the key 61 are sent simultaneously to the first inputs of the adder 63 and to the input of the circuit "OR" 62.

 To explain the principle of operation of BU 6, we consider several possible situations.

Suppose that all the commands "PP" and "SS" take the value "0", which corresponds to the case of lack of synchronization and exceeding the threshold in n receivers of the CA. In this case, “0” is generated at the output of the keys 61 ₁ ... 61 _n , “0” is also formed at the output of the OR circuit 62 and at the output of the adders 63 ₁ ... 63 _n .

The signals from the outputs of the adders 63 ₁ ... 63 _n are fed to the inputs of the switch 5 and are the control commands of the switch (KUK). In this case, if the CSC takes a value of “0”, the outputs of the switch are connected to its right inputs (ie, to SU 2), if the CSC takes a value of “1”, the outputs of the switch connect to its left inputs (ie to SU 4 ) T.O. in the considered case, all receivers are connected to SU 2.

 Consider another situation, when “1” appears on two inputs of keys 61, then “1” is formed at their outputs, “1” is also formed at the outputs of OR circuits 62, and “0” is formed at the output of adders “modulo 2”.

 T. about. and in this case, the Rx devices remain connected to the right inputs of the switch 5, i.e. to SU 2.

 That is, if PfP 1 has entered synchronism and the level of its measured signal exceeds a threshold, then it remains connected to the right inputs of switch 5, i.e. to SU 2.

 If "1" is formed at the output of at least one of the blocks 61, and "0" is present at the output of the other blocks 61, then "1" is formed at the output of the corresponding adders 63, which provides the connection of the inputs of the corresponding PRMs to the left inputs of the switch 5, t. e. to the outputs of SU 4.

 In this case, the signal to the input of the corresponding PFPs will be supplied through blocks 3 and 4, while in the BR 3 a powerful signal will be cut.

 Thus, receivers in which “SS” is “1” and “PP” is “1” are connected to SS 2. PFPs in which “SS” are “0” and “PP” are “0” subject to availability "SS" - "1" and "PP" - 1 for at least one PfP, are connected to SU 4.

 The structural diagram of the notch block of SHPS 3 is shown in figure 3, where it is indicated: 31 - multiplier (phase modulator), 32 - notch filter (RF), 33 - multiplier (phase remodulator), 34 - attenuator, 35 - bandpass filter (PF) tuned to the frequency of the SHPS carrier and having a passband equal to the SHPS band, 36 — switch, 30, 37, 38 — delay elements, 39 — key, 391 — reference signal driver.

BR Z contains n series-connected identical rulers. The output of SU 2 is connected to one of the inputs of BR З, which is connected to the first ruler containing a delay element 30 ₁ connected in series, multiplier 31 ₁ , RF 32 ₁ , multiplier 33 ₁ , attenuator 34 ₁ , PF35 ₁ , switch 36 ₁ , another input which is connected to the input of the multiplier 31 ₁ .

Another input BR Z through a series-connected driver of the reference signal 391 ₁ and key 39 _{1 is} connected to one of the inputs of the multiplier 31 ₁ and through the delay element 38 ₁ to another input of the multiplier 33 ₁ .

The delay elements 30 ₁ , 37 ₁ , 38 ₁ are adjustable and are used when necessary. Other inputs of the key 39 ₁ and the switch 36 _{1 are} combined and are another input BR Z.

 BR Z works as follows.

For each line 1. ..n BR З, an input mixture and a reference signal (OS) from one of the PFPs are supplied (each line has its own corresponding to its OS number). In addition, a CVL command corresponding to this ruler (a ruler enable command) is generated, which is generated in control unit 6. In the event that the CVL takes the value “1”, the i-th line is fed from the PFP _i OS _i and it is cut from the input mixture SHPS _i emitted by AS _i (i = 1 ... n). If KVL _i takes the value "0", then the input mixture passes through the ruler without change.

 Consider the work, for example, of the 1st line.

From SU 2, one of the inputs of the BR 3 receives the input mixture, which is fed to one of the inputs of the switch 36 ₁ through the delay element 37 ₁ , and to the other input through series-connected blocks 30 ₁ , 31 ₁ , 32 ₁ , 33 ₁ , 34 ₁ , 35 ₁ .

A reference signal (OS ₁ ) is supplied to the other input of BR З from the PFM1 ₁ , which is directly transmitted through the key 39 ₁ to the input of the multiplier 31 ₁ , and to the input of the multiplier 33 ₁ through the delay element 38 ₁ . Note that the OS received on the BR Z are synchronous with the corresponding SHPS in the input mixture.

OS ₁ supplied to the input of block 31 ₁ provides a "convolution" of the input SHPS ₁ emitted by AC ₁ . OS ₁ is a reference signal PFP ₁ - SHPS ₁ , which can be formed at the local oscillator frequency.

The minimized signal from AC _{1 is} rejected in block 32 ₁ and, therefore, does not pass to the output of the line. At the same time, signals from other speakers pass to the output of the line, because in block 31 ₁ , additional manipulation is imposed on them according to the law of OS ₁ , and in block 33 ₁ due to multiplication with the same OS ₁ it is removed.

The input mixture, from which SHPS ₁ is excluded, from AS ₁ through the attenuator 34 ₁ and PF 35 ₁ (tuned to the carrier SHPS common for all speakers with a bandwidth equal to the spectrum of SHPS) is fed to the second input of the switch 36 ₁ .

To the control input of the switch 36 ₁ is the command to turn on the line (KVL ₁ ) from the control unit 6, which is also supplied to the key 39 ₁ .

In the event that KVL ₁ takes the value “1”, its second input is connected to the output of the switch 36 ₁ , and the key 39 _{1 is} opened. If KVL ₁ has the value "0", the first input is connected to the output of the switch 36 ₁ , and the key 39 _{1 is} closed, preventing the passage of OS ₁ .

T. about. depending on the value of the waterline ("0" or "1"), the input mixture passes through the ruler without change or with the exception of the composition of SHPS ₁ .

Delay elements 37 ₁ and 38 ₁ are used if necessary, they provide signal alignment with respect to travel time in cases where the delay in the circuit elements is large enough and affects the quality of work, which can occur at high clock frequencies of the memory bandwidth.

The attenuator 34 _{1 is} used to equalize the gain of the upper and lower branches of the ruler.

Using blocks 37 ₁ and 34 ₁ allows you to provide the same transmission coefficient and propagation time in the upper and lower branches of each line of BR Z.

Various types of balanced modulators can be used as multipliers 31 ₁ and 33 ₁ (see G.I. Tuzov Statistical Theory of Receiving Complex Signals, M .: Sov. Radio, 1977, p. 51).

 The rest of the BR Z lines work in the same way, while the i-th line is fed with the input mixture that has passed through the (i-1) -th previous lines, in each of which the signal from the corresponding speaker can be cut or not cut depending on its level at the entrance of the BR Z.

The execution of the driver of the reference signal 39 ₁ depends on the structure of the PFP. So, if the PFP receives only one BSC (operation without a pilot signal), the reference signal supplied from the PFP output to the input of the BR З is the reference PSS PFP. In this case, the driver of the reference signal 39 ₁ degenerates into a delay element, which is used, if necessary, to ensure the synchronism of the reconstructed BSS with the reference SRP (taking into account the delay of the signals in the processing paths).

In the case of using the pilot signal for transmitting the ACS AC, block 39 ₁ can be performed, for example, in the same way as the transmitting equipment in autosw. N 300946 with the difference that the role of FOPP and GLP in it is performed by the receiver bandwidth shown in Fig.4.

In this case, reference SRP is supplied to the input of block 39 ₁ from the outputs of blocks 43 and 45, which, if necessary, can be delayed in block 39 ₁ using adjustable delay elements. Those. in this case, block 39 ₁ is a four-phase FM ShPS driver, in which reference SRPs of the BS receiver, which has entered synchronism, the level of the received signal of which exceeds the permissible value, are used as reference SRPs.

The hardware solution of such a technical solution is shown in Fig. 7, where it is indicated: 71 — local oscillator frequency generator (GCH), 72, 73 — multiplier (phase manipulator), 74 — adder, 75, 76 — delay elements, 77 — phase shifter 90 ^o (PV).

The driver of the reference signal 39 ₁ contains delay elements 75 and 76, which through the respective multipliers 72 and 73 are connected to the corresponding inputs of the adder 74, the output of which is the output of the driver of the reference signal. The output of the GCHG is connected to the corresponding inputs of the multiplier 72 and through the PV 77 the multiplier 73. The inputs of the delay elements 75 and 76 are the inputs of the driver of the reference signal 39 ₁ .

 Delay elements 75 and 76 are introduced to ensure the synchronism of the generated reference signals with the output BPS taking into account possible signal delays in the equipment paths.

 The driver of the reference signal operates as follows. At the inputs of the shaper serves two reference SRP clock and information channels PFP, presented in figure 4 (outputs of blocks 43 and 45).

 In blocks 75 and 76, the GCG signals are phase-shifted, summed in block 74.

 PFP 1 can be performed, for example, as described in ed. N 300946, H 03 C 3/40.

 The structural diagram of such a PFR is shown in Fig. 4, where it is indicated: 41 — synchronization device, 42, 46 — multipliers, 43 — orthogonal PSP driver (FOPP), 44 — formation device (UV), 45 — reference PSP generator (GOPP), 47, 49 - bandpass filters (PF), 48 - phase detector (PD).

 In this case, the synchronization signal (SS) is generated in the synchronization device 41. The output of the SS is the output of the block 41 connected to the inputs of the blocks 43 and 45. The PFP output, which is connected to the BR З, is the outputs of the blocks 42 and 45, which form the SRP clock and information channels.

 The output of the PFP connected to the AUS 7 is the output of the PF 49, where the "folded" ShPS is highlighted.

 In the event that the formation of the BBA in the AS is carried out without using a clock signal (pilot signal), the PFP will contain one channel, while only one SRP will be fed to the input of the BR З.

 In the case of performing PFP, respectively, figure 4, AUS 7 can be made in the form of n independent rulers, each of which is associated with one of the receivers. Each line is a series-connected detector and a comparison circuit with a fixed threshold, the level of which is set depending on the structure of AACC and the dynamic range of signal levels in the system. The command from the outputs of the comparison circuit ("0" or "1") is sent to control unit 6.

 SU 2 and SU 4 provide matching antenna-feeder devices with the inputs of the receivers (n + 1) and n, respectively, and can be performed, for example, using decoupling resistors.

 T. about. the claimed equipment ensures the exclusion of the interfering effect of powerful signals 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.

 When using the inventive equipment, either the need to adjust the power of the AC transmitters is eliminated, while the throughput of the system 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 also simplifies hardware implementation of transmitters and to increase throughput.

 In a system using prototype equipment, there will always be restrictions on the minimum allowable distances between the CA and the AC, due to the finite number of gradations of the power of the transmitters.

 In the claimed equipment due to the exclusion from the composition of the input mixture of powerful interfering signals, such restrictions are absent, which increases the operational and tactical characteristics of the system.

 The rejection of high-power broadband radios from near speakers removes the restrictions on the minimum allowable distances between the central speakers and the speakers that take place for the prototype.

Claims (1)

The receiving equipment of the base station of the radio communication system with code division multiplexing, containing the first matching device, a signal level analyzer, n receiving devices, the information outputs of which are information outputs of the equipment, and the signal outputs are connected to the corresponding inputs of the signal level analyzer, characterized in that a notch block is introduced high-power broadband signals, a second matching device, a switch, while n signal outputs of the first matching device are connected to

signal inputs of the switch, the (n + 1) -th signal output of the first matching device through series-connected block rejection of powerful broadband signals and the second matching device is connected to

the signal inputs of the switch, n signal outputs of which are connected to the corresponding signal inputs of n receivers, the reference outputs of which are connected to the reference inputs of the notch block of powerful broadband signals, and the control outputs are connected to the control inputs of the control unit, the (n + 1) -th control input of which is connected with the control output of the signal level analyzer, the first control output of the control unit is connected to the control input of the switch, and the second control output of the control unit is connected to the control input input block rejection of powerful broadband signals.

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