SU1389004A2 - Synchronizer - Google Patents

Abstract

The invention relates to the field of radio communications and may be. Used in communication systems with phase-shift keyed noise-like signals. The purpose of the invention is to reduce the time of entry into synchronism. The device contains a receiver 1, two multipliers 2, 10, block 3. search, r-4 copies of the signal, time selector 5, amplitude detector 6, band-pass filter 7, shaper 8 clock pulses, r-r 9 reference signal, gating unit 11, a strobe pulse shaper 12, a delay block 13. The goal is achieved by introducing the S / N ratio measurement unit 14, the control unit 15 for controlling the voltage. A device according to claim 1, characterized in that the block 14 comprises a serially connected first key and a first averaging unit and a serially connected second key and a second averaging unit. 1 hp f-ly, 2 ill. about s (l

Description

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The invention relates to radio communication, can be used in communication systems with phase-shifted noise-like signals and is an improvement of the invention according to the authors. St. No. 936448.

The purpose of the invention is to reduce the time of entry into synchronism.

Fig. 1 shows the structure of the time selector 5 and the post-electrical circuit of the synchronization device; in fig. 2 is a structural electrical circuit for measuring the signal-to-noise ratio.

The synchronization device contains: receiver 1, first multiplier 2, search block 3, generator 4 copies of the signal, time selector 5, amplitudes

detector 6, band-pass filter 7, clock generator 8, reference signal generator 9, second multiplier 10, gate unit 11, gate pulse generator 12, delay unit 13, signal-to-noise ratio measurement unit T4, control voltage generation unit 15 . Here, the signal-to-noise ratio measurement unit 14 comprises the first and second keys 16 and 17, the first and second averaging blocks 18 and 19, the subtraction unit 20, the division unit 21.

The synchronization device operates as follows.

The received phase-manipulated noise-like signal, namely, the phase-assisted linear-frequency-modulated signal is fed to the input of receiver 1, which implements the functions of preamplification and selection. Next, the filtered signal is fed to the second multiplier 10 and simultaneously to the time selector 5. The signal from the output of the time selector 5 is fed to the input of the amplitude detector 6, where the envelopes of the response of the time selector 5 occur.

At the initial moment of operation, the band-pass filter 7 is at rest. The control signal to the strobe unit 11 is not applied, and it passes the signal mixture (envelopes).

responses of the time selector 5) to the input of the bandpass filter 7.

The band-pass filter 7, excited by, from this mixture, alternates the voltage of the first harmonic signal with a frequency equal to the frequency of the envelopes of the responses of the time selector 5. Further, this voltage, acting on the driver -8, is converted into a sequence of pulses that are output the driver 8 arrives at the delay unit 13, establishing the phase relations between the sequence of response envelopes necessary for normal operation

pulse response at the shaper output 8, Toe. the driver 12 generates strobe pulses used to control the gate unit 5, which goes into operation and starts to pass the received mixture to the input of the band-pass filter 7

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only at the time intervals of the expected arrival of the useful signal (envelopes of the responses of the time selector 5).

The sequence of clock pulses from the output of the delay unit 13 is fed to the input of the driver 12, namely, to the input of the amplifier-limiter of this block, from the output of the limiter, a signal pre-amplified by a two-stage amplifier, is fed to the pulse shaper, the rectangular pulses with steep 30 edges amplify arrive at the second input of the strobe unit 11, which is put into operation and ya begins to pass to the input of the bandpass filter 7 the received mixture only during the expected arrival time intervals useful signal. In addition, the strobe pulse sequence is also used to control the first and second keys 16 and 17 of block 14, and the strobe pulse sequence arriving at the swarm input of the second key 17 is generated with some delay in relation to the pulses arriving at the second input of the first key 16 The functions of the delay element are performed by the dispersive ultrasonic delay line. At the same time, a mixture of the useful signal and noise from the output of the amplitude detector 6 is fed to the inputs of the first and second keys 16 and 17, which pass this mixture only during the time interval for the existence of strobe pulses at their second inputs. Thus, at the output of the first key 16, a sequence of useful pulses is formed in a mixture with noise within the range of existence of these pulses - Uc ,. At the output of the same v40

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A key 17 forms a periodic sequence of noise segments at intervals of the existence of gating pulses - Uyj.

The resulting pulse sequences are fed to the inputs of the first and second blocks 18 and 19, respectively, at the output of which the signals UC are formed. Uw. The signals from the outputs of the first and second blocks 18 and 19 of averaging are fed to the inputs of the subtraction unit 20, the output of which forms a signal corresponding to the average value of the useful component Uc.

The signal from the output of the subtraction unit 20 is fed to the first input of the block 21, the second input of which receives the signal from the output of the second averaging unit 19, i.e. average noise component of the received signal. The block 21 is thus modified. The device according to claim 1, characterized in that the signal-to-noise ratio measurement block comprises a first key connected in series and a first averaging unit, a second key connected in series, and

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The ratio between the useful and noise components of the received signal-25 is the second averaging block, with inla. The signal from the output of the block 21 is the input of the inputs of the first and second em to the input of the block 15. The keys are combined and are the input

The control voltage from the output of the signal-to-noise ratio measurement unit,

The first and second control inputs of which are the control inputs of the first and second keys, the outputs of the first and second averaging blocks are connected respectively to the first and second inputs of the subtraction unit, the output of which is connected to the first input of the division unit, the second input of which is connected to the output of the second averaging unit, and the output of the unit of the de-block 15 formation is fed to the band-pass filter 7. In the event of a change in the disturbance situation (i.e., when the signal-to-noise ratio changes upwards), the quality factor of the resonance Stem filter 7 is reduced in accordance with the voltage at the output of block 15.

The clock pulses from the output of the imaging unit 8 act on the block 3, which performs the restructuring of the generator 4 and the control of the generator 9.

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neither is the output of the signal-to-noise ratio measurement unit.

Claims (2)

1. Synchronization device according to auth. No. 936448, characterized in that, in order to reduce the time to synchronization, the output of the amplitude detector is connected with the control input of the bandpass filter through the signal-to-noise ratio measurement unit and the control voltage generation unit introduced in series, the first and second outputs of the strobe pulse generator are connected to the first and second control inputs of the signal-to-noise ratio measurement unit, respectively. 2. The device according to claim 1, characterized in that the signal-to-noise ratio measurement unit comprises a first key connected in series and a first averaging unit, a second key connected in series and the second averaging unit, wherein the information inputs of the first and second keys are combined and are the input thirty 35 40 neither is the output of the signal-to-noise ratio measurement unit. FIG.