RU1807575C - Simulator of communication system with noise-like signals - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to expand the functionality by changing the parameters of pseudorandom sequences (SRP). The device comprises a clock generator 1, a message generator 2, a pseudo-random sequence generator 3, a modulator 4, a reference generator 5, a coherent detector 6, a correlation processing unit 7, an onopV sequence generator 8, a synchronization analyzer 9, a control unit 10. Binary the message generated by the message former 2 is encoded by one of two different structures of the combined memory bandwidth in the memory block forming block 3. In the modulator 4, the radio signal is generated, and in block 6 its detection, The output signal of block 6 is sent to the correlation processing block 7, where the mutual correlation functions of the received and reference signals generated by block 8. independent input into synchronism of the reference SRP unit 8 according to the signals generated by the control unit 10. In the synchronization analyzer 9, the correlation functions of the received signal and copies of bine SAPs formed block 8. In the absence of synchronism between a received signal and a synchronization copies analyzer 9 outputs a correlation processing unit 7 of the signal the resumption of the search. 1 ill. t / s

Description

The invention relates to the field of radio engineering, in particular to information transmission technology, and can mainly be used to study signal transmission in broadband communication systems.

The purpose of the invention is to reduce the search time of a signal by a delay in transmitting information by varying pseudorandom sequences (SRP),

The drawing shows a structural circuit diagram of a simulator of a communication system with noise-like signals.

The device comprises a clock generator 1, a message generator 2, a pseudo-random sequence generating unit 3, a modulator 4, a reference generator 5, a coherent detector 6, a correlation processing unit 7. A reference sequence generator 8, a synchronization analyzer 9, and a control unit 10.

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The device operates as follows.

A binary sequence of information symbols is received from the message generator 2 to the information input of the pseudo-random sequence forming unit 3. At the output of block 3, depending on the value of the information symbol, form one of the Two structures of the combined memory bandwidth (CPSP) with a clock-gt. Determined by the generator of Pulses 1. The CPSC is formed by multiplexing the symbols of N generators of the initial CPS according to a certain law. The choice of the structure of the CPSS is made by changing the law of multiplexing. Modulator 4 performs phase manipulation of the signal of the reference oscillator 5 by the CPSP video signal. The noise-like radio signal thus formed is fed to the signal input of the coherent detector b, where the inverse conversion to the video signal is performed. From the output of the coherent detector, the signal is supplied to the signal input of the correlation processing unit 7 and to the information input of the synchronization analyzer 9. In the reference sequence generator 8, N initial SRPs are formed based on the idea of the structure of the CPSS. identical SRP and CPSP block 3. Signals of the initial SRP are fed to the N reference inputs of the correlation processing unit 7. and two CPSP structures are fed to the first and second reference inputs of the synchronization analyzer.

The control inputs isi of the control signal generator 8 from the control unit 10 receive N sequences of clock pulses, which are formed from the output signal of the clock 1.

The decrease in the search time for the delay of the CPSC is based on the possibility of parallel and independent input into the synchronism of the generators of the initial CPS by the received CPS. This possibility is due to the fact that the inter-correlated cir- cular function of the CPSP and the initial SRP has a pronounced maximum at delay shifts that are multiples of the period of the initial SRP. If all the generators of the original SRP on the transmitting and receiving sides are synchronous in delay, then the reference and received CPPS will also be synchronous.

The correlation processing unit 7 performs the operations of determining the values of the inter-correlation function of the received CPSS and the original SRPs, comparing them with a threshold and outputting the result of the comparison to the signal inputs of the control unit 10. If the values of the inter-correlation functions of any initial SRPs do not exceed the current delay threshold, then in the control unit one pulse of their clock sequences is excluded, arriving at the corresponding control inputs of the driver of the reference sequences. Thus, the asynchronous source SRPs are shifted

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by one clock cycle and the process of calculating the values of the bi-correlation functions in the correlation processing unit is repeated. When the values of the inter-correlation functions of all the initial SRPs exceed a threshold at the control output of block 7, a signal appears that permits the arrival of the CRPS to the reference inputs of the synchronization analyzer 9, which verifies the synchronization of the initial SRPs by

0 calculating the values of the inter-correlation functions of the received and supporting CPSS. If one of these values exceeds the threshold, then a signal will appear at the information output of the synchronization analyzer,

5 corresponding to the received message. Otherwise, from the control output of the synchronization analyzer, a resumption signal is received at the corresponding input of the correlation processing unit

0 search and the entire process of synchronization of the original SRP will be repeated,

Due to the fact that the initial SRPs are synchronized independently of each other and from the received structure of the CSSP (since

5 different structures of the CPSS are formed from the symbols of the same initial SRP), it can be argued that the total synchronization time is commensurate with the synchronization time of one initial SRP. This allows

0 achieve your goal.

Formula and Simulator of a communication system with noise-like signals, containing a generator

5 clock pulses, a message generator, a pseudo-random sequence generator, a modulator, a coherent detector and a correlation processing unit, as well as a generator

0 reference sequences and a reference oscillator, the output of which is connected to the reference inputs of the Modulator and the coherent detector; the output of the clock generator, the information input of the synchronization analyzer is connected to the output of the coherent detector, and the first and second reference inputs are connected respectively with the first and second outputs of the reference sequence generator, the control inputs of which are connected to the corresponding outputs of the control unit, the reference input of which is connected to the output of the clock generator, and the signal inputs are connected to the corresponding

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the outputs of the correlation processing unit, the control output of the correlation processing unit is connected to the control input of the reference sequence generator, and the control input of the correlation processing unit is connected to the corresponding output of the synchronization analyzer, the information output of the synchronization analyzer is the output of the device.