SU1510106A1 - Device for receiving telegraph signals - Google Patents

Abstract

This invention relates to radio. The purpose of the invention is to improve the noise immunity in spaced reception. The device contains a limiting amplifier 1, a demodulator 2, a low-pass filter 3, shapers 4 and 8, a weight calculation unit 5, a multiplier 6 and an adder 7. The input signal through the limiting amplifier 1, demodulator 2, filter 3 and shaper 4 rectangular pulses are fed to computation unit 5. It measures the distortions of signal elements, the magnitude of which depends on the signal-to-noise ratio in the receive channel, and calculates the weighting coefficients from the averaged value of these measurements resident 6. It also receives a signal from the output of filter 3. Next, the weighted signal is fed to the adder 7, and then to the driver 8, which converts the signal into square-shaped pulses. 1 il.

Description

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The invention relates to the field of radio communications and can be used both as a device for receiving signals arriving on a single channel, as well as for organizing a diversity system.

The purpose of the invention is to improve the noise immunity in spaced reception. .ten

Figure 1 shows the structural electrical circuit of the device for receiving telegraph signals; in fig. 2- diversity system

The device contains an amplifier-limiter 1, a demodulator 2, a low-pass filter 3, the first driver 4, a weight calculation unit 5, a multiplier 6, an adder 7, the second driver 8.20

The device works as follows.

The input signal through the amplifier-limiter 1, demodulator 2 and low-pass filter 3 is fed to the input of shaper A, from the output of which square-shaped pulses are fed to the input of block 5 for calculating weighting coefficients. In block 5, the measurement of signal element distortions is measured, the magnitude of which depends on OTHO-1 signal / interference in the receive channel, and the weighting coefficients are calculated from the averaged value of these measurements.

The weighting factors thus determined are fed to the input of a multiplier 6, to the second input of which a signal is fed from the output of the low pass filter 3. The weighted signal from the 40 output of the multiplier 6 is fed to the input of the adder 7, the second input of which is the second input of the device (Bx.2) and is intended to supply a weighted signal from another analogous device when organizing a diversity reception system. The signal from the output of the adder 7 is fed to the input of the imaging unit 8, is converted by it into square-shaped pulses, and is fed to the output of the device (output; 2). The output of the adder 7 is the first output of the device. (Out.1) and is intended to be connected to the input (Bx.2) of another similar device when organizing a system of separated receive telegraph signals. An example of building a reception system over three separated channels using

this device is shown in figure 2. The output signal of such a system is the decision generated by shaper 8 on the sum of weighted signals of all reception channels, which accumulate sequentially from device to device in adders 7. At the same time, the weights for the outputs (Output C) are estimates of the quality of individual reception channels .

When exposed to signals without interference or with the same signal-to-interference ratio in different receiving channels, the temporal distortions for all channels will be equal and, accordingly, the weights will be equal at the inputs of the multipliers 6. In this case, the adders 7 will accumulate signals of equal level and at the outputs .3) there will be equal evaluation of the quality of individual channels.

When exposed to signals with different signal / interference ratios, a channel with a lower signal-to-noise ratio will correspond to a lower value of the weighting factor and, consequently, a lower signal level at the output of multiplier 6 and a smaller channel quality assessment value generated at the output (Output; 3) of the corresponding devices.

Claims (1)

Invention Formula A device for receiving telegraph signals containing a series-connected amplifier-limiter, demodulator, low-pass filter and the first driver, with the input of the amplifier-limiter being input-. The house of the device, characterized in that, in order to improve noise immunity at diversity reception, weighted serial factors, multiplier, adder and second driver are introduced, the output of the low-pass filter is connected to the second input of the multiplier, the output of the first driver is connected to the input of the weight calculator coefficients, the second input of the adder is the second input of the device, and the outputs of the adder, the second imaging unit and the weighting factor calculator are The first, second and third outputs of the device. HtmpoucmSo for receiving cuenaAoS i telegraphs Sx.2 HcmpoOcmSo for receiving telegraphic / m syenalo8 Z eight( Icmpoucmdo for reception of telegraph / s signal 3; Bttx.t. T Sx.2 for receiving syenalo8 Z te eight( VYH.Z In 2 fie.2