SU1140262A1 - Device for reception of frequency-phase-shift keyed signals - Google Patents

Abstract

1. A DEVICE FOR ACCEPTING A PARTICLE-TIME-PHASOMANIPULATED SIGNAL, containing a serially connected first mixer, a band-pass filter, a synchronization unit and a pseudo-random sequence generator, the outputs of which are connected to the additional inputs of the synchronization unit and to the inputs of the decoder, as well as the successively connected first multiplier the second mixer., the second input and output of which are connected respectively to the output of the local oscillator and to the inputs of the block narrow-band filter, the outputs of which are connected. The information inputs of the switch, the control input of which is connected to the output of the frequency selection program block, the first input of which is connected to the output of the switch and to the first input of the first mixer, so that, in order to understand noise tolerance due to static error elimination in conditions of intense noise; four delay elements are introduced into it, the meander shaper and the second multiplier in series, narrowband filter, amplitude detector, third multiplier, filter. frequencies and amplifier, the output of which is connected to the second input of the synchronization unit, the first input of which is connected to the inputs of the second multiplier, and the output of the decoder through the first delay element connected in series and the meander shaper is connected to the second input of the frequency selection program block and to the input of the second delay element whose output is connected to the second input of the third multiplier, and the corresponding P1 output of the generator is pseudo. random sequence through the third delay element is connected to the first input of the first multiplier, the second input of which is connected to the inlet. house of the fourth delay element, the output of which is connected to the second input of the first mixer. 2. The device according to claim 1, about tl and N9 E) in that the synchronization unit contains in series N9 the first adder, the first multiplier and the first narrowband filter and the subtractive unit connected in series, the second multiplier, the second input of which is connected to the second input of the first multiplier, second uekopolosny filter, the third multiplier, low pass filter, amplifier, the second adder. and a controlled clock, the output of which is the output of the synchronization unit, the first, second and

Description

additional inputs of which are respectively the second input of the first multiplier, the second

the input of the second adder and the inputs of the first adder, which are connected to the inputs of the subtractive unit.

The invention relates to radio technology and can be used in communication systems with frequency-manipulated signals.

A device for receiving signals with an incoherent structure, containing a reference discrete frequency-manipulated signal shaper, whose input is connected to the output of a pseudo-random sequence generator, is known as a multiplier, the first input of which is connected to the output of the reference discrete frequency-manipulated signal shaper, and is fed to the second input the received signal as well as the discrete information extraction unit. the input of which is connected to the output of the multiplier, and the envelope detector lj ...

However, the known device has a large loss in signal processing and low noise immunity.

g

The closest in technical essence to the proposed invention is a device for receiving frequency-phase-manipulated signals, comprising a first mixer connected in series, a bandpass filter, a synchronization unit and a pseudo-random sequence generator, the outputs of which are connected to the additional inputs of the synchronization unit and to the inputs of the decoder, as well as sequentially connected the first multiplier and the second mixer, the second input and the output of which are connected respectively with the output of the local oscillator and with the inputs a narrow band filter unit whose I outputs are connected to the information inputs of the switch, the control input of which is connected to the output of the frequency selection program block, the first input of which is connected to the switch output and to the first input of the first mixer 2j.

However, this device has a low noise immunity.

The purpose of the invention is to increase noise immunity by eliminating static errors in conditions of intense noise.

The goal is achieved by the fact that a device for receiving a frequency-phase-manipulated signal containing a first mixer, a band-pass filter, a synchronization unit and a pseudo-random sequence generator, whose outputs are connected to additional inputs of the synchronization unit and to the inputs of the decoder, and also serially connected first multiplier and a second mixer, the second input and output of which are connected respectively to the output of the local oscillator and to the inputs of the narrowband filter unit in, the outputs of which are connected to the information inputs of the switch, the control input of which is connected to the output of the frequency selection program block, the first input of which is connected to the output of the switch and the first delay of the first mixer, the first delay element, the meander and the series-connected second multiplier narrowband filter, amplitude detector, third multiplier, low pass filter and amplifier, the output of which is connected to the second input of the synchronization unit, the first input of which is connected to the input s the second multiplier, while the output of the decoder through serially connected the first delay element and the meander shaper is connected to the second input of the frequency selection program block and to the input of the second delay element whose output is connected to the second input of the third multiplier, and the corresponding generator 3 output of a pseudo-random sequence through the third the delay element is connected to the first input of the first multiplier, the second input of which is connected to the fourth input, the delay element whose output is li ne to a second input of the first mixer. The synchronization unit contains the first adder connected in series, the first multiplier and the first acceleration filter and the successively connected subtraction unit, the second multiplier, the second input of which is connected to the second input of the first multiplier, the second narrow-band filter, the third multiplier, low-pass filter, amplifier, the second an adder and a controlled clock generator, the output of which is the output of the synchronization unit, the first, second and additional inputs of which are respectively v The input is the input of the first multiplier, the second input is the second sum of the torus and the inputs of the first adder, which are connected to the inputs of the subtraction unit. FIG. 1 shows the structural electrical circuit of the proposed device; in fig. 2 - the same block synchronization. A device for receiving frequency-phase-controlled signals contains (FIG. 1) first mixer 1, band-pass filter 2, synchronization unit 3, switch 4, block 5 of the frequency selection program, block 6 of narrow-band filters, first multiplier 7, second mixer 8, local oscillator 9, generator 10 pseudo-random sequence, decoder 11, square cutter 12, first delay element 13, amplifier 14, second multiplier 15, narrowband filter 16, amplitude detector 17, third multiplier 18, low-pass filter 19, second, third, third second and four th elements 20-22 delayed. Synchronization unit 3 consists of (Fig. 2) first, second and third multipliers 23-25, respectively, first 26 and second 27 narrowband filters, low-pass filter 28, amplifier 29, first 30 and second 31 adders, subtractive controlled clock unit 32 generator 33 The device operates as follows. 62 The device (Fig. 1) receives the frequency-phase-manipulated signal, which is a vibration, the phase of which is manipulated according to the law of the characters of the pseudo-random sequence, and the carrier frequency changes in steps according to the law of another pseudo-random sequence. The device operates in sync mode, i.e. when the receiver is tracking the signal delay. At the same time, at the output of the first multiplier 7, a signal without phase shift keying is generated, containing only frequency jumps. For each frequency value there is a C4 | dj narrowband filter in block 6 of narrowband filters, through which the signal passes to the outputs of switch 4, under the influence of control signals from the output of block 5 of the frequency selection program (which sets the order of frequency switching and in the simplest case is a shift register with feedbacks and a decoder, the number of outputs of which is equal to the number of frequencies used) switch 4 per clock with frequency jumps connects the outputs of block 6 of narrowband filters to the first input of the first mixer 1, What If the signal at the outputs of the block of 6 narrow-band filters coincided with the frequency jumps of the received signal, the received signal must be delayed. For this, there is a fourth delay element 22 in the proposed device. At the output of the first mixer 1, a signal is formed in which the frequency manipulation is cleared, and only phase manipulation according to the pseudo-random sequence law is contained. The synchronization unit 3 monitors the delay of the phase-shifted signal at the output of the band-pass filter 2. However, this signal is delayed relative to the received signal due to the delay in the band-pass filter 2 and the fourth delay element 22. Therefore, the signal arriving at the first multiplier 7 from the generator output 10 of a pseudo-random sequence must advance the phase-shifted signal at point B (Fig. 1) at the corresponding input of block 3. This is achieved by signal to the first multiplier 7 coming from the generator leading output 10 pseudo-random sequence through the third delay element 21, which is necessary so that the moments of the phase manipulation are received by the frequency-phase-manipulated signal exactly coincide with the moments of switching the symbol s pseudo-random sequence. Cro. Since the switching times of the signal entering the first mixer 1 through the fourth delay element 22 coincided with the switching times of the switch, it is necessary for the driver 11 to form a signal with an advance by an integer number of clock cycles, which is then further delayed by the first element 13 delays necessary. for more accurate matching of switching times often by switch 4 with the moments of frequency change of the received signal. Shaper 12 square wave will generate a signal with a duty cycle of 2 and This is equal to the duration of one frequency of an element, and is a pending multivibrator, which forms a pulse with a duration equal to half the duration of one frequency element. Shaper 12 meander can be excluded if you use Two decoder and .trigger. Meander frequency switching signal. elements are necessary for proper operation of the chain of a second multiplier 15, a narrow-band filter 16, an amplitude detector 17, a third multiplier -18, a low-pass filter 19, and an amplifier 14. This chain provides an additional error signal for: hold reference signal. The second multiplier .15 is used as a quad, the output signal of the second harmonic of the intermediate frequency is produced at its output, and the phase shift keying is eliminated. This signal is filtered by a narrowband filter 16, and the amplitude detector 17 selects its envelope. If there is no delay mismatch, then a signal with a constant amplitude is formed at the output of narrowband filter 16, and a signal appears at the output of amplitude detector 17, which then goes to the first input of the third multiplier 18, to the second input of which through the second delay element 20 square wave frequency switching frequency elements. At the output of the third multiplier 18 there will also be a meander. A low pass filter 19 extracts the constant component of this signal, which in this case is zero. If the switching time of the frequencies at switch 4 does not correspond to the moments of a jump in the frequency of the received signal at the second input of the first mixer 1, then the amplitude of the signal at the output of narrowband filter 16 will cause dips that appear as amplitude detector 17. When multiplying this signal with a frequency meander The interleaving of the frequency elements is a constant component that is extracted by the low pass filter 19 and is amplified by the amplifier 14.. . The second element 20. delay causes a gamma-time delay of the bandpass filter 2 and the narrowband filter 16. The synchronization unit 3 operates as follows (Fig. 2). The inputs A and B receive pseudo-random sequences differing by a shift by one clock frequency period. In the first adder 30, a sum signal is generated, which is fed to the first multiplier 23, and in the subtractive unit 32 a difference signal is generated, which is fed to the second multiplier 24, to the other inputs of the first and the second multiplier 23 and 24 receives the intermediate frequency signal, phase-shifted by the law of a pseudo-random sequence. The amplitude of the intermediate frequency signal at the output of the first and second narrow-band filters .26 and 27 depends on the delay delay. When these signals are multiplied, the output of the third multiplier 25 o is the error signal, which is then filtered by the low pass filter 8., amplified by the amplifier 29 and fed to the second accumulator 31. The second input of the second adder 31 receives an additional signal. (at the input of G). an agreement with the output of the amplifier 14 (Fig. 1). The total error signal is fed to the input of the controlled clock generator 33, while the clock frequency changes and a delay adjustment is made. Thus, the advantage of the proposed device in comparison with the known devices of this type, as well as in comparison with the prototype, is that it provides higher noise immunity due to the introduction of elemental delays that eliminate the influence of the group delay time of the band-pass filters in the static mode. operation of the device, which in turn reduces the loss in processing the received signal. In comparison with the known, the proposed device has a better noise immunity, since phase jumps do not occur, which reduces losses. In addition, the formation of an additional delay mismatch signal allows an increase in the synchronization accuracy, which has a positive effect on the noise immunity of the entire device.

Claims (2)

1. RECEIVER FREQUENCY PHOTOMANIPULATED SIGNALS, containing in series the first mixer, a band-pass filter, a synchronization unit and a pseudo-random sequence generator, the outputs of which are connected to additional inputs of the synchronization unit and to the decoder inputs, as well as the first multiplier and the second mixer connected in series., the second input and output of which are connected respectively to the output of the local oscillator and to the inputs of the block of narrow-band filters, the outputs of which are connected. to the information inputs of the switch a ,, the control input of which is connected to the output of the frequency selection program block, the first input of which is connected to the output of the switch and to the first input of the first mixer, characterized in that * in order to increase the noise immunity by eliminating the static error under conditions of intense interference, four elements of za are introduced into it. the holders, the shaper of the meander and • in series connected a second multiplier, a narrow-band filter, an amplitude detector, a third multiplier, a low-pass filter and an amplifier, the output of which is connected to the second input of the synchronization unit, the first input of which is connected to the inputs of the second multiplier, while the output the decoder through series-connected the first delay element and the meander driver is connected to the second input of the frequency selection program block and to the input of the second delay element, the output of which is connected to the second input of the third multiplier, and the corresponding output of the pseudorandom sequence generator via a third delay element connected to the first input of the first multiplier, a second input coupled to vho- .. fourth delay element house ₄ whose output is connected to the second input of the first mixer. 2. The device according to π. 1, the synchronization unit comprising in series connected a first adder, a first multiplier and a first narrow-band filter and a series-connected subtracting unit, a second multiplier, a second input of which is connected to a second input of the first multiplier, a second narrow-band filter, a third multiplier, a lower filter frequencies, amplifier, second adder. and a controlled clock, the output of which is the output of the synchronization unit, the first, second and additional inputs of which are, respectively, the second input of the first multiplier, the second 1140262 -. the input of the second adder and the input of the first adder, which are connected. with the inputs of the subtracting block.