SU1631739A1 - Method for wideband signal reception - Google Patents

Abstract

The invention relates to radio engineering and can be used to receive a broadband signal in the presence of narrowband interference. The purpose of the invention is to increase the noise immunity with respect to narrowband interference coming from different points in space, with uniform spectra of the useful signal and noise. The device implementing the method comprises antennas 1, narrowband filters 2, first multipliers 3, low pass filters 4, dividers 5, block 6 for determining the minimum signal, first adders 7 | second multipliers 8, extreme regulators 9, second adder 10, compression filter 11, frequency channels 12. The goal is achieved by maximizing the antenna patterns in the direction of the wanted signal, and at least in the direction of interference. 3 il. /)

Description

The invention relates to radio engineering and can be used to receive a broadband signal in the presence of narrowband interference.

The purpose of the invention is to increase the noise immunity with respect to narrowband interference coming from different points in space, with uniform spectra of the useful signal and noise.

Fig. 1 shows a structural electrical circuit of a device for receiving a broadband signal for implementing the method; figure 2 - graphs

deactivating devices; fig.Z - radiation pattern of the antenna (DN) device.

The device for receiving a broadband signal contains antennas 1, narrow band filters 2, first multipliers 3, low pass filters 4, dividers 5, minimum signal block 6, first adders 7, second multipliers 8, extreme regulators 9, second adder 10 , filter 11 compression, frequency channels 12.

The device works as follows.

ABOUT

with

with so

The reception is carried out at the antennas 1. From the output of each antenna 1, the signal arrives at the combined inputs of the corresponding group of frequency channels 12, which form a spatial channel (not allocated in figure 1). The frequency characteristics of channels 12 are formed using narrowband filters 2. The current value of the signal power in each frequency channel 12 is determined by the serially connected multiplier 3 and filter 4.

The weighting of the signals in the frequency channels 12 occurs in accordance with the formula

JU; A / P ;, where A is a constant;

P, is the total power of the useful signal and interference in the i-th (i 1,2, ..., M) frequency channel 12, carried out using a divider 5.

Block 6 measures the minimum level

power in channels 12. In multiplier x 8, the minimum power level in channels 12 is multiplied by the output signals of the spatial channels. Extreme regulators 9 are designed to determine the orientation of antennas 1, at which the signals at the outputs of the multipliers 8 are maximum.

Antenna Orientation 1 may

is as follows.

Rotating the radiation pattern of the antenna 1 within 0-360 °, remember its orientation, at which the maximum voltage occurs at the outputs of the multiplier 8. Orient the antenna 1 in this direction. Similarly, orient all other antennas 1.

The sum signal from the output of summer 6 is fed to filter 11, which compresses the useful wideband signal either in frequency or in time.

Suppose that the device contains 6 frequency channels 12 with adjacent frequency characteristics (Fig. 2a). In the reception band, there are 6 narrowband interference (shown in FIG. 2a by vertical lines). The level of narrowband interference is significantly higher than the useful signal level and noise. Direction to the wanted signal and interference is unknown. The signal spectrum and atmospheric noise is uniform.

with

five

0

five

0

35

„

45

50

55

Antenna 1 is conventionally shown placed at one point.

Sources of interference (P, -P6), the useful signal (C) and the receiver (P ") are arranged as shown in Fig.Z.

The device contains two antennas 1 (their radiation patterns are shown by a solid line and a dotted line, respectively). The first three frequency channels 12 are connected to the output of the first antenna 1, and the remaining three frequency channels 12 are connected to the output of the second antenna 1.

By rotating the radiation pattern of one of the antennas 1 within 0-360, we get two maximums of voltage at the output of the multiplier 8. One, when the minimum of the pattern is directed towards interference P, and the other at interference P2. While the interference is absent respectively in the first and third channels 12.

Let, taking into account the orientation of the maximum of the radiation pattern in the case when the minimum. Diagram of antenna 1 is directed towards interference P (FIG. 3), it has a large gain of the useful signal. Then the direction of the radiation pattern of the antenna 1 is chosen by zero for the interference P, |.

Reasoning in the same way, it can be shown that the other antenna 1 will be directed at the minimum of the radiation pattern at the HZ interference.

Thus, as a result of the orientation of the antenna 1, the interference II and P3 are suppressed. In the reception band, 4 narrowband interferences remain (Fig. 26). Since the levels of narrowband interference are significantly higher than the level of the useful signal and noise. That signals at the outputs of 3, 5 and 6 frequency channels 12 will be virtually absent. The input of the filter 11 receives a signal and noise, the spectrum of which is limited by the bandwidth of 1, 2 and A channels (Figure 2b).

Thus, all six interferences are suppressed, with only three parts of the spectrum affected by interferences are rejected.

Claims (1)

Invention Formula The method of receiving a broadband signal, which consists of forming N spatial reception channels, the signal of each spatial reception channel is filtered out onto M .f FIG. 2 Fig.Z