SU634468A1 - Complex signal retrieval device - Google Patents

Description

electrical circuit: - and the proposed device.

The complex signal search device contains a block of 1 frequency controllers, a delay tracking unit 2, a correlation unit 3, a detector 4, an element OR 5, a key 6, a counter 7, decoders 8 and 9, and a memory element 10.

The device works as follows.

A signal with an unknown frequency and delay and noise through the GCH frequency unit G consisting of mixer 11, local oscillator 12 and demodulator 13 are fed to correlation unit 3, in which the mutual correlation function of the received signal and noise and the reference signal from the main generator 14 reference signals. The chip size is compared with a certain threshold level. At the end of the analysis, scanner unit 15 polls detector 4, changes the temporal position of the signals of the main generator 14, and via key 6 issues a command to synchronize the additional generator 16 of the reference signals according to the main signal. If the analysis does not exceed the threshold, then scanning unit 15 resets correlation unit 3.

If the threshold is exceeded, a signal appears at the appropriate output of detector 4, which, through the OR 5 element, moves counter 7 from the position "O to position" 1. The signal from the output of the decoder 8 acts on the memory element 10, which closes the key 6, preventing synchronization of the additional generator 16 and blocks the switch 17, which issued the reference signal of the additional generator 16 to the discriminator 18 identical to the reference signal of the main generator 14, provides the maximum response to output block 3 correlation. That is, the tracking unit 2 proceeds to the analysis of the given threshold level.

At the same time, the scanning unit 15 (CBS1) 1 is inserted into the correlation unit 3, translates the main generator 14 to the next position, and so on. That is, scanning the search area continues. If the tracking unit 2 decides that a signal has been found, the search is stopped and the tracking mode begins. If during the recheck time the threshold unit 2 in the process of further scanning did not exceed the threshold, then after the time allotted for the recheck, the scan unit 15 returns the counter 7 and the memory element 10 to the initial state and scanning the search area continues.

If, during the recheck time, the threshold is repeatedly exceeded, the signal from the output of the detector 4 through the element OR 5 transfers the meter 7 to the state in which the scanning unit 15, after

The decoder 9 receives information about the termination of scanning. In this case, the signals from the output of the detector 4 do not switch over in the switch 17, since it is 5 blocked by the memory element 10.

In this case, the device waits for the analysis to be completed by the tracking unit 2 of the first threshold exceeding. At the end of the analysis 0, the scanning unit 15 returns the counter 7 and the memory element 10 to the initial state, resets the correlation unit 3 and synchronizes the auxiliary generator 16 without changing the temporal position of the main generator 14.

The proposed device provides a shortening of the search time by reducing the loss of time for analyzing false alarms, the likelihood of which in multichannel devices is significant. In the case of fairly rare false alarms, there is no loss of time for the analysis of such conditions, since scanning of the search area is not interrupted.

Claims (1)

1. USSR author's certificate number 425367, cl. H 04 L 1/10, 1972.