SU1662015A1 - Wideband signal transmission and reception method - Google Patents

Abstract

The invention relates to methods for transmitting and receiving a broadband signal with a continuous spectrum over communication channels with concentrated interference. The goal — to improve the reception accuracy of a broadband signal with a continuous spectrum — is achieved by dynamically transforming the spectrum of a broadband signal, followed by its frequency separation, low-frequency filtering, and multiplexing the resulting signals by frequency. 2 Il.

Description

The invention relates to the field of radio engineering and communications and can be used in the transmission of unconsolidated wide-band signals, such as television.

The aim of the invention is to improve the reception accuracy of a broadband signal with a continuous spectrum.

Figure 1 shows signal spectra explaining the method; 2 is a structural electrical circuit diagram of a device implementing the method.

The device comprises a broadband signal former 1, a dynamic transducer 2. an inverse dynamic transducer 3, a frequency division unit 4, a frequency multiplex unit 5, and a wideband signal receiver 6.

The method of transmitting and receiving the broadband signal is as follows.

On the transmission side, the broadband signal generated by shaper 1 is converted in a dynamic converter 2 into a signal in which the frequency components of the spectrum cyclically move within the frequency spectrum of the wideband signal.

At the receiving side of the inverse dynamic converter 3, cyclical movement of the frequency components of the spectrum of the wideband signal is synchronous with the transmitting side, inverse to the movement of the frequency components in the dynamic converter of the 2 transmitting side. As a result of these transformations, noise or noise having frequency centered or the distribution pattern, uneven in the frequency spectrum of the wideband signal, is transformed from a constant time distribution into AC Referring varied in each unit band wideband signal from a minimum value to a maximum at a frequency corresponding to the frequency of the cyclic movement.

The frequency of cyclic movement and the number of frequency bands into which the wideband signal is divided by block 4 are selected from

T Fn "FB,

(L

WITH

about

Os

about

ate

where D F - the width of the spectrum of the broadband signal;

Fn is the frequency of cyclic movement;

N is the number of frequency bands;

FB is the upper limit frequency of the wideband signal.

After conversions in converters 2 and 3, the wideband signal (FIG. 1a) is divided into 4 elementary band 4 filters. In order to reduce linear distortions when dividing and generating a wideband signal, the filtering bands of these filters are common, and the frequency response amplitude in the frequency response band in the filtering band for each of the filters has equal meaning and different signs, i.e. the total frequency response of the filters in the frequency band of the wideband signal should be uniform. The elementary bands of the wideband signal selected by the filters are transferred to the low-frequency range using the subcarriers Ft-FN in which they are filtered by low-pass filters (Fig. 1b). The cut-off frequency Fcp of the low-pass filters is selected from the condition

 N

 FCp FN.

Filtration of elementary frequency bands by low-pass filters allows you to select the average value of the variable noise (noise) component, the same in each band. The cleaned narrow-band signals, each at its input, go to block 5, where the initial wideband signal is formed (Fig. ) using subcarriers FI-FN. Since each of the elementary frequency bands has the same average noise power values lower than the maximum possible after the low-pass filter, the recovered broadband signal also has noise power distributed throughout

the frequency band is uniform, i.e. the amount of noise is also less than the maximum possible.

Claims (1)

Invention Formula The method of transmitting and receiving a broadband signal, which means that the transmitting side cyclically transforms the spectrum components of the broadband signal within the frequency range occupied by this spectrum, and then transmits the resulting signal over the communication channel, and from the communication channel, the signal is synchronized with the transmitting side; the signal is restored by cyclically moving the components of the spectrum of the wideband signal in the direction opposite to displacement of the spectrum components by to the transmitting side, the reconstructed signal is subjected to frequency division, characterized in that, in order to improve the reception accuracy of a broadband signal with a continuous spectrum, frequency separation of the reconstructed signal at the receiving side is carried out by bandpass filtering in the frequency bands that evenly overlap the entire frequency range of the spectrum of the broadband signal, the transfer of signals allocated for bandpass filtering to the low frequency region using frequency subcarriers, and subsequent low frequency filtering of the received signals frequency separation of the reconstructed signal transfers the signals resulting from low-frequency filtering to the wideband signal using subcarriers used in frequency division, the cyclic frequency moving the components of the broadband signal spectrum. Much less than the upper frequency of the wideband signal spectrum but greater than the bandwidth set by bandpass filtering on the receiving side.