SU1474859A1 - Discrete signal transmission for multibeam communication channel - Google Patents

Abstract

This invention relates to radio. The purpose of the invention is to improve the noise immunity of receiving discrete information in multipath propagation. The device contains information and test signal generator 1, intersymbol distortion compensation unit 2, demodulator 3, channel response measurement unit 4, predistortion generation unit 5, reference signal generation unit 6, information signal duration control signal receiving unit 7, block 8 control the duration of the information signals, block 9 of the transmission of control signals. To achieve the goal, N-1 single-beam allocation units 10, N-1 subtractors 11, N key elements 12, block 13 of the maximum beam auto selector, N threshold elements 14, N input element OR 15 are entered into the device. If the signal level is that the reliability of receiving information falls below the permissible, then block 8 makes a decision about the need to increase the duration of the elementary signal. Such an increase provides an increase in the energy of the signals and therefore an increase in the signal / interference ratio. 1 il.

Description

The invention relates to radio communications and can be used to transmit information over multipath channels.

The aim of the invention is to improve the noise immunity of receiving discrete information in multipath propagation.

The drawing shows a structural diagram of the device.

The device contains information and test signals shaper 1, intersymbol distortion compensation unit 2, demodulator 3, channel response measurement unit 4, predistortion generation unit 5, reference signal generation unit 6, block

7 reception of control signals by duration of information signals, block

8 control the duration of information signals, control signal transfer unit 9, single beam extraction unit 10, K-1 subtractors 11, N key elements 12, maximum beam auto selector 13, N threshold elements 14 and N input element OR 15 .

The device works as follows.

Shaper 1 information and test signals generates a sequence of information radio signals corresponding to the sequence of incoming discrete symbols and periodically following test pulses. This sequence comes from the output of the imaging unit 1 to the communication link, for example, consisting of a radio transmitter with an antenna, a propagation medium and a radio receiver with an antenna. From the output of the communication line, the signals go to the first block 10 for selecting a single

to pens them. To do this, in block 5, a signal is generated that corresponds to intersymbol interference from previous symbols, and then in block 2 is subtracted from the incoming signal. Thus, intersymbol distortion is compensated. From the second output of the channel response measurement unit 4, the generated pulse also arrives at the first input of the reference signal generating unit 6, which in block 6 provides for the formation of a reference signal synchronous with the signal arriving with the ffa information of the demodulator 3 input signal 3. This reference signal is used for mutual correlation demodulation.

The multipath signal from the receiver output also goes to the first input of the first subtractor 11, to another input - the signal of the first beam from the output of block 2 of the first block 10. Thus, at the input of the second block 10 there are signals of the remaining N-1 beams, while the second of the beams received by the radio receiver are first processed for the second block 10. Similar equalizers are turned on at the inputs of all the other blocks 10, and the first inputs of them are given the signals of the remaining rays from the output of the previous subtractor, and the others are signals of single signals. s rays with the previous block 2 block output 10. As a result of this incorporation. blocks 10 signal processing number of each of them strictly corresponds to the number of the received beam.

In the process of transmitting information, block 4 of each of the N blocks 10 selects the channel impulse response and,

ray. The unit 4 for measuring the response of channel 45 therefore has information

about the transmission coefficient for each of the N rays of propagation. Signals of signal levels from the third output of blocks 4 of all N blocks 10 enter the N-input block 13 of the maximum beam selection, where you have the highest voltage proportional to the transmission coefficient and the maximum beam, N controls the outputs of block 13 through threshold elements 14c - key elements 12 are connected to the corresponding input of the element 15 of the output of the demodulator 3 of that bl

determines the type of impulse response to periodically embedded test pulses in the information sequence, which in the predistortion formation block 5 regulates the linear quadrupole formed by the delay line with taps so as to compensate for the intersymbol distortion of all incoming rays except the first one. In addition, the value of the type of impulse response allows us to determine the nature of intersymbol distortion and, consequently, has the information

on the transmission coefficient for each of the N Rays. The signal levels from the third outputs of blocks 4 of all N blocks 10 are fed to the N-input block 13 of the maximum beam selection, where the selection of the highest voltage proportional to the transmission coefficient of the maximum beam takes place over the N control outputs of block 13 through the threshold elements 14c. key elements 12 are connected to the corresponding input of the OR element 15 of the output of the demodulator 3 of the block 10, in which the highest transmission coefficient. The signal level of the selected (highest) beam comes from the signal output of the block 13 to the block 8 for controlling the duration of the information signals.

If the signal level is such that the reliability of the reception of information falls below the permissible, then block 8 decides whether it is necessary to increase the duration of the elementary signal. This increase provides an increase in the signal energy and, therefore, an increase in the signal-to-noise ratio.

Claims (1)

At the second output of block 8, a signal is generated (for example, a sequence of clock pulses) ensuring synchronization of demodulators 3 and formation of all N blocks 6 of the reference signal with a manipulation speed equal to the speed of manipulation in the communication line, the latter being determined by the control input of the modulator of the transmitting part of the device on the reverse channel of the first output of block 8 through blocks 9 and 7. The invention A device for transmitting discrete signals in a multipath communication channel, containing in the transmitting part a shaper of information and test signals, whose information input is the input of the device, and the output of the control unit for controlling the duration of information signals are connected to the control input, and in the receiving part a single beam extraction unit containing a series-connected intersymbol distortion compensation unit, a demodulator and a predistortion generation unit, a channel response and bl block measurement unit When forming the reference signal, the information input of the intersymbol distortion compensation unit is connected to the input of the channel response measurement unit and is the input of the single beam extraction unit, the first output of the channel response measurement unit is connected to the second input of the predistortion generation unit, the output of which is connected to the additional input of the intersymbol compensation module distortion, the second output of the reaction channel measurement unit is connected to the first input of the reference signal generation unit, the output 0 five 0 five 0 five 0 five 0 five which is connected to the first control input of the demodulator, the second input of the reference signal generation unit is connected to the second control input of the demodulator and is the control input of the single beam extraction unit, the third output of the channel measurement measurement unit of the single the beam, the demodulator outputs and the intersymbol distortion compensation block are respectively the information output and the output of a single beam of the single beam extraction block, and the serially connected block controlling the duration of the information signals and the control signaling transmission unit; the second output of the control unit of the duration of the information signals is connected to the control input of the single beam extraction unit, characterized in that, in order to increase the noise immunity, to receive discrete information in multipath propagation, 1 single beam extraction units, N-1 subtractors, N threshold elements, N key elements, N input element OR, and maximum beam auto selection block, with input of the K-th block single beam extraction is connected to the input of the K-th subtractor, the output of a single beam of the K-th single beam extraction block is connected to the input of the subtraction of the K-th subtractor, the output of which is connected to the input of the (K + 1) -th block of a single beam, the output of the control unit the duration of the information signals is connected to the control inputs of all single beam extraction blocks, the measurement outputs of the single beam extraction blocks are connected respectively to the N outputs of the maximum beam auto selection block, the signal output of which is connected to each unit of the control signal duration, and N control outputs through threshold elements are connected respectively to control inputs of N key elements, information outputs of N single beam extraction units are connected respectively to information inputs of N key elements, whose outputs are connected respectively to N inputs of an N input element OR, the output of which is the output of the device.