SU1396286A1 - Device for shaping channel signal for multichannel communicationr systems with frequency-division multiplex - Google Patents

Abstract

The invention relates to radio engineering and communication and allows to reduce the frequency band occupied by the channel signal. The device contains a low-pass filter 1, an amplitude-pulse modulator 2, a generator of 3 subchannel carrier signals, a distributor of 4 pulses, an adder 5 and N circuits consisting of subtractor 6, convolution unit 7, delay blocks 8, and attenuators 10, 11. An input signal, such as a telephone, passes through filter 1 and is converted by an amplitude-pulse modulator 2 into a sequence of narrow samples. The distributor 4 divides the samples of the channel signal into slower groups of samples of subchannel signals. Groups of samples of subchannel signals are sent to subtractor 6 respectively. chains. The subtractor 6 also receives several samples of other subchannel signals preceding in time the given subchannel counting and passing through the corresponding. blocks 8, 9, and attenuators 10, 11. In block 7, the convolution of a narrow subchannel carrier signal is performed. The signals of blocks 7 of all circuits are summed in the adder 5 .. 1 Il.

Description

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The invention relates to radio engineering and communications, and can be used to construct multichannel communication systems with frequency channel multiplexing.

The aim of the invention is to reduce the frequency band occupied by the channel signal.

The drawing shows a structural electrical circuit of the proposed device.

The device for forming a channel signal for multi-channel communication systems with frequency multiplexing of channels contains a low-pass filter 1, an amplitude-pulse modulator 2, a generator 3 of subchannel carrier signals, a distributor of 4 pulses, an adder 5 and N circuits, each of which contains the subtractor 6, the convolution unit 7, the first and second delay blocks 8 and 9 and the first and second attenuators 10 and 11.

The device (normalization of the channel signal for multichannel communication systems with frequency channel multiplexing works as follows.

Input continuous source signals (for example, telephone) from the output of filter 1 are converted using a pulse-amplitude modulator 2 V to a sequence of narrow samples with pulse-amplitude modulation of the 1st kind, and with the help of the distributor D the channel signal samples are divided into slower: groups of samples of subchannel signals, which are fed to the subtractors; 6, to the other inputs of which from the outputs of the circuits of the subtractors 6 of other circuits through the first and second blocks 8 and 9 and the first and second attenuators 10 and 11 comes several times to the other sub-channel signal samples preceding in time this sub-channel count. The resulting resultant sub-channel sample arrives at the signal input of block 7. At the reference inputs of block 7 synchronously with the sub-channel samples, narrow-band sub-channel signal carriers from generator 3 are received,

During the time interval allocated for the transmission of the subchannel carrier signal, the convolution of the narrow subchannel sample is performed.

with a subchannel signal of carriers and signals from the outputs of blocks 7 (CS) are summed in the adder 5

Claims (1)

Formula Invention five 0 five 0 five 0 five 0 five A channel signal shaping device for multi-channel communication systems with frequency multiplexing of channels, comprising a series-connected low-pass filter and an amplitude-impulse modulator, the control input of which is connected to the clock output of the sub-channel carrier signal generator, characterized in that Ope for reducing bandwidth the frequencies occupied by the channel signal are entered an adder, a pulse distributor and N circuits, each of which contains a series-connected subtractor and a convolution unit, according to Consequently, the first delay unit and the first attenuator and the second delay unit and the second attenuator connected in series, the inputs of the first and second delay units are combined and connected to the output of the subtractor p whose first input is the signal input of the circuit, the second and third inputs of the subtractor are respectively, the first and second correction inputs of the circuit, whose signal output is the output of the convolution unit, and the first and second correction outputs of the circuit are respectively the outputs of the first first and second attenuator, while the output and control input of the amplitude-pulse modulator are connected respectively to the signal and clock inputs of the pulse distributor, whose N outputs are connected to the signal inputs of the corresponding N circuits, the signal outputs are connected to the N inputs of the adder, the second inputs of the blocks convolutions of all N circuits are connected to the corresponding N outputs of the generator of subchannel carriers, in addition, the first correction is the main output of each i-th phase (i 15 N) connected to the first corrective th input of each (1H-1) -th (mod N) circuit, and the second corrective output of each j-th circuit (j 1 ,, N) is connected to the second corrective input of each (+2) -th (mod N) chains.