SU559422A2 - Device for receiving pseudo-random delay-modulated signals - Google Patents

Description

In the drawing, a structural electrical circuit of the device is shown for receiving pseudo-random zadarned-modulated signals.

The device for receiving pseudo-random delay-modulated signals consists of a searchless receiver 1, a pulse generator 2, a square wave generator 3, a phase detector 4, a filter 5, a capture indicator 6, a controlled generator 7, a shift register 8, a synchronous detector 9, a multiplier 10, an additional filter 11, a decision block 12, a trigger 13, a decoder 14, a difference block 15, a digital discriminator 16, a threshold element 17, a key 18, one control input of which is connected via a threshold element 17 to the output of the filter 5 a - yield capture indicator 6.

The proposed device works as follows

The searchless receiver 1, based on the received pseudo-random oscillation containing the information modulation of the pseudo-random sequence (PSP) on the delay, makes a rough estimate of the transmitted information at each time instant. At the output of the pulse driver 2, in accordance with the estimation, positive pulses of constant amplitude are obtained when a non-delayed bandwidth is present in the input oscillation, or negative amplitudes of a constant amplitude when a delayed bandwidth is present. These impulses of constant amplitude trigger the generator of the meander 3. At the same time, the trigger 13 using the decoder 14 and the shift register 8 outputs a reference square wave. Phase detector 4 produces a voltage that is proportional to the time error between the onopiibiM square wave and the square wave generated by the square wave generator 3. This voltage goes through the filter 5 and the capture indicator 6 to the controlled oscillator 7, which changes the clock frequency shift 8, which reduces the mismatch between the meanders. At the moment when the voltage value at the output of the filter 5 is reduced to the pre-set level, the threshold element 17 issues a command to the key 18, which starts to transmit pulses from the decoder 14 to the input of the shift register 8 and thereby begins to rebuild the reference signal by delaying the advancement PSP pulses in the shift register. The reference signal is tuned until a voltage appears at the output of the digital discriminator 16 and the pickup indicator 6 is triggered, which means the start of tracking on the discriminatory characteristic, i.e. implementation of timing synchronization and clock

frequency The fine tuning of the time field and the clock frequency of the reference signal is performed by the digital discriminator-16 after the command of the capture indicator 6, which disconnects the input of the controlled oscillator 7 from the output of the filter 5 and connects it to the output of the digital discriminator 16, the input signals of which are PSP, removed from shift register 8, and output oscillation

synchronous detector 9, which removes the harmonic carrier.

Using the shift register 8, delayed and undelayed syncronized with the input bandwidth are generated, which are fed to the multiplier 10, where they are multiplied with the output oscillation of the synchronous detector 9, filtered in an additional filter 11 and fed to a decision block 12, which decides the information symbol.

Claims (1)

Invention Formula Device for receiving pseudo-random delay-modulated signals by aut. St. No. 445168, which means that, in order to reduce the synchronization time, a key is entered between the decoder output and the second input of the svidiga register, one control input of which is connected to the filter output through the additionally introduced threshold element and the other with the output of the capture indicator. fx