SU995343A1 - Device for processing video signals of detector transmitter - Google Patents

Description

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The invention relates to receiving devices and can be used in optical location and video paths of radio systems for detecting and temporarily linking pulsed signals with a wide dynamic range in the presence of interference and a fixed average frequency of false alarms.

Devices for processing video signals of detector receivers with a dynamic range of input signals are known, in which compression of a dynamic range is performed by an automatic gain control with signals (ARUS), which ensures high linearity of the receiving path and, accordingly, small errors of temporal anchoring of signals. In this case, the actuating element ArUS can be located in the path of the carrier frequency 2, either in video path 3, or in both paths

To stabilize the average frequency of false alarms of the receiver when operating in a wide dynamic range of interference in the video signal processing device, it is necessary to introduce an automatic gain control controller (ARUSH).

Known devices for processing video signals of detector receivers with a wide dynamic range of signals and interference, containing ARUS and ARUSH 4.

The presence in the detector receiver of two automatic controllers (ARUS and ARUSH) considerably complicates its design, tuning, and worsens its dynamic parameters.

However, the main disadvantage of these devices is that they cannot be efficiently (from the point of view of the possibility of simultaneous realization of the ultimate real sensitivity of the receiver and maximum accuracy of the time coupling of signals in wide dynamic) 5 signal ranges and noise) used in receivers when the intensity the recorded signals are random at a low frequency of their occurrence, as it takes 20 long enough to achieve the required amplification of the reception path of the ARUS signaling pulses.

The closest in technical essence to the present invention is a device for separating optical signals, comprising an m-stage video amplifier with adjustable gain and with input delay lines of each amplification stage, connected to an automatic gain control unit for noise, a detection unit and a time reference signals (OVPS unit) connected to the input of the video amplifier, and the element. OR 5. However, ha |) the performances of a known device deteriorate sharply when the device operates against interference, the intensity of which varies over a wide dynamic range. The purpose of the invention is to reduce the error of the temporal reference of pulsed signals, fluctuating, their amplitude in a wide dynamic range against the background of noise, the intensity of which also varies in a wide dynamic range. To achieve this goal, the video signal processing device of the detector receiver with automatic stabilization of the average frequency of false alarms, contains a t-cascade video amplifier with adjustable gain and delay lines at the input of each amplification stage, connected to the automatic noise control unit, the detection unit and temporal signal assignment (OVPS unit) connected to the input of the video amplifier; and the OR element, additionally introduced m OVPS blocks, m-1 gates, m delay lines, with the input of each amplification stage of the video amplifier through the serially connected OVPS unit and the delay line connected to the inputs of the OR element, the output of each OVPS unit (except the first) is connected to a valve whose output is connected to the Inhibit the OHVP unit and the second input of a subsequent amplification stage valve; the output of the first OHPS unit is connected to the Inlet to the AVC unit and the second input of the second amplifier stage of the video amplifier. The drawing shows a structural diagram of the proposed device for processing video signals of the detector receiver with automatic stabilization of the average frequency of false alarms. The device contains a t-cascade video amplifier 1 with adjustable gain, line 2 delays at the input of each stage 3 amplifiers of video amplifier 1, automatic adjustment block 4 - noise amplification (ARUSH): units 5 OVPS valves 6, delay lines 7, element 8 OR Proposed The video signal processing device of the detector receiver operates as follows. From the detector output, a mixture of signal with noise is fed to the input of the device, where it is branched off to the input of video amplifier 1 and OVPS unit 5. The drawing shows the case when the control voltage from the output of ARUSH 4 is applied to each cascade 3 gain of video amplifier 1. In general, depending on the required depth of adjustment, the number of stages covered by the feedback can be different. In addition, the system of automatic stabilization of the noise level at the output of the processing device can be performed by another scheme (for example, by multiloop). In the video amplifier 1, the signal passes through the w-connected in series cascades 3 amplification, at the input of each of which the delay lines 2 are connected. The signal from the noise from the output of the corresponding cascade 3 amplification of video amplifier 1 is input to each block of the 5 OFAC. When the amplitude of the signal exceeds the detection threshold of the first OVPS unit 5 (in the drawing is left), the standard signal from the output of this unit is via the delay line 7 and the OR 8 element is output to the device. In order for amplified amplified signals from the outputs of the respective subsequent cascades 3 amplifiers of video amplifier 1 not to pass through the device output, prohibiting the inputs of the subsequent OVPS units 5 from the output of the first OVPS unit 5 receive a standard signal that closes these units. This signal goes to the second OVPS unit 5 directly from the output of the first OVPS unit 5, and to the next through the corresponding number of valves 6 connected in series. To the last OVPS unit 5 (on the far right), the signal passes through m-1 valves 6. Lines 2 the input delays of each stage 3 of the amplification of video amplifier 1 are used for the time delay of the signal at the output of the corresponding OVPS unit 5. The magnitude of their delay should be such that the prohibitory signal to the inhibitory input of the subsequent OVPS unit 5 would arrive earlier than the amplified signal from the output of the corresponding stage 3 to the signal input of this unit. If the input signal amplitude is insufficient to trigger the first OVPS unit 5, then one of the subsequent OUPS units 5 will work, the output of which the signal from the output of the corresponding stage 3 amplified in video amplifier 1 will exceed the threshold level of amplitude discrimination of this OVPS unit 5. Just as in the previous case, the signal from the output of the activated unit 5 OVPS passes through its delay line 7, and the element OR 8 to the output of the device, and also enters the prohibition inputs of all subsequent units 5 OVPS. In the mode of receiving the min. Signals, only the last unit 5 of the AFC is activated. Signal delay values

in delay lines 7, are selected from the condition of simultaneous occurrence of a signal at the device output, regardless of the amplitude of the input signal, and are determined by time delays in the corresponding number of delay lines 2 and amplification stages 3 and the corresponding OVPS unit 5. Therefore, the delay line 7 at the output of the first OVPS unit 5 should have a maximum delay time, and at the output of the last OVPS unit 5 there is no such delay line.

Automatic stabilization of the level of false alarms at the output of the device is carried out by the ARUSH unit 4, the input of which receives a mixture of signal and noise from the last stage 3 of amplification of video amplifier 1.

The number of cascades 3 amplification video amplifier 1 and the number of blocks 5 OVPS is determined by the ratio of the required dynamic range of the video signal processing device of the detector receiver to

, the dynamic range of one cascade of the video amplifier, and to exclude temporal faults on the threshold of operation of neighboring OVPS units 5, the dynamic range of the latter should slightly exceed the dynamic range of the stages 3 of the video amplifier gain. The synchronous occurrence of standard pulses at the output of the device at different amplitudes of the input signals over the entire working range of their values (i.e., regardless of which IFAP unit 5 passed the signal to the input of the proposed device) is provided by introducing delay lines 7, the time delay value which was mentioned above. The temporary position of the standard pulse at the output of the device is rigidly fixed at the time of the appearance of the input signal at the input of the device and does not depend on its amplitude in a wide dynamic range. Parallel-sequential processing of signals in noise with a large dynamic range (both signals and noises) provided by additionally introduced blocks 5 OVPS, gates 6, delay lines 7 and the element OR 8, eliminates all adjustments of the preceding detector of the receiver and retains its optimal mode of operation, which contributes to the preservation of the limiting threshold-time characteristics of the proposed device at any point in the dynamic ranges of signals and interference (noise).

The proposed device is quite simply implemented on commercially available electrical radio elements by the domestic industry. Delay lines can be made on coaxial cable / type RK or microstrip versions. OVPS units that detect signals with reference to their temporal position are built on high-speed comparators of the type 597CA1.

The advantages of the proposed device for processing video signals detector. Compared with the known ones of this class, the receiver has limit threshold-time characteristics in wide dynamic ranges of signals and interference due to the high linearity of the amplitude characteristics of the device for signals both at any (in the operating range) their amplitude and at any (in the working range) interference intensity, as well as the preservation of the limiting threshold-time characteristics of the device at any frequency of the signal pulses following the automatic selection of the undistorted signal pulse, applied to the detection and formation of a standard pulse determining the temporal position of the signal.

The implementation of the proposed video signal processing device of the detector receiver will allow the replacement of a wide range of known similar devices that can solve only particular problems in a wide range of signals and interference.

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Claims (3)

Invention Formula A video receiver detector processing unit with automatic stabilization of the average false alarm frequency, containing a t-cascade video amplifier with adjustable gain and with input delay lines for each gain stage, connected to the automatic gain control unit for noise, the detection unit and time 5 signal attachments (OVPS unit), connected to the input of a video amplifier, and an OR element, characterized in that, in order to reduce the error in temporal coupling of pulsed signals that fluctuate in amplitude in a wide dynamic range of background noise, the intensity of which also varies in a wide dynamic range, additional m OVPS units, m-1 gates, m delay lines are entered into it, with the input of each amplification stage of the video amplifier through a sequence of 5 but connected OVPS units and a delay line connected to the element inputs LEE, each block output OVPS (except the first) is connected to the input gate whose output is connected to input "block prohibition Q OVPS and the second input of the valve of the subsequent amplification stage, the output of the first OVPS unit is connected to the input of the “Prohibition of the OVPS unit and the second input of the second stage amplifier of the video amplifier. 5 Sources of information taken into account during the examination 1. USSR Copyright Certificate No. 504293, cl. H 03 G 3/00, 1976. 2. USSR author's certificate number 496651, cl. H 03 G 3/20, 1976. 3. US patent number 3003065, cl. 250-207, 1961. 4 USSR author's certificate No. 434566, cl. H 03 G 3/22, 1974. 5Authorial certificate of the USSR No. 324508, cl. G 01 J 1/44, 1972 (prototype). output