SU1478348A2 - Communication channel quality analyzer - Google Patents

Abstract

The invention relates to telecommunications and can be used in a data transmission system. The purpose of the invention is to extend the functionality by analyzing N-band signals with time-frequency modulation. The analyzer contains pulse selectors for duration, counters 2 information symbols, elements of comparison 3 and 4, delay element 5, element OR 6, chroniser 7. The goal is achieved by introducing additional (N-1) selectors 1, (N-1) counters 2 , (N-1) elements of comparison 3 and 4, delay element 9, frequency distributor 8, counter 10, the number of symbols, comparison blocks 11, 12, error counter 13, block 14 of the memory of the lengths of error-free intervals and their connections. 1 il.

Description

UNION OF ADVISORS

SOCIALIST

REPUBLIC „„ SU 1478348 A 2

STATE NOMINATION

BY INVENTIONS AND DISCOVERIES

AT GNST USSR

DESCRIPTION OF THE INVENTION

TO AUTHOR'S CERTIFICATE

<· '. \ A (61) 743214 (21) 4207249 / 24-09 (22) 06.03.87 (46) 07.05.89. Bull. No. 17 (72) M.M. Markov, M.A. Boyarshinov,

OF. Klimov and V.M. Likharev (53) 621.395.66 (088.8) (56) USSR Copyright Certificate No. 743214, cl. H 04 B 3/46, 1978.

(54) COMMUNICATION CHANNEL QUALITY ANALYZER (57) The invention relates to telecommunications and may used in data transmission system. The purpose of the invention is the expansion of functionality by analyzing η-band signals with time-frequency modulation. The analyzer contains selectors 1 pulses in duration, counters 2 information symbols, elements of comparison 3 and 4, delay element 5, element OR 6, chroniser 7. This goal is achieved by introducing additional (p-1) selectors,.

I, (p-1) counters 2, (p-, 1) comparison elements 3 and 4, delay element 9, frequency distributor 8, counter 10 number of characters, blocks

II, 12 comparisons, counter 13 errors, block 14 memory lengths of error-free intervals and their relationships. 1 ill.

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The invention relates to telecommunications, can be used · in data transmission systems and is an improvement on the author St. No. 743214.

The purpose of the invention is the expansion of functionality by analyzing η-band signals with time-frequency modulation.

The drawing shows a structural electrical diagram of the proposed analyzer.

The quality of the communication channel analyzer contains selectors 1.1—1.η pulses in duration, counters 2.1-

2.η information symbols, first comparison elements 3.1-3.η, second comparison elements 4.1-4.η, delay element 5, OR element 6, clock 7, frequency 'allocator 8, additional delay element 9, symbol count 10, the first and second comparison blocks 11 and 12, an error counter 13 and a memory unit 14 of error-free interval lengths.

The analyzer works as follows. ’

The signal input of the frequency distributor 8, which divides the signal under study by frequency, receives an additive mixture of noise and signal with time-frequency modulation. According to the signal from the additional output of the chronizer 7, it is made in the frequency / / distributor. 8 is the selection of the signal in frequency and its passage ’to the corresponding selector 1 pulses in duration. Each selector 1 selects only those pulses whose duration is within the selection interval of the known duration of information symbols. The pulses from the output of each selector 1 go to the input of the corresponding counter 2 information symbols, and the inputs of the counter 10 of the number of characters receive signals from the outputs of all selectors 1. Counter 2 information symbols accumulates the number of units for the observation time interval. The outputs of each counter 2 information symbols are connected to the corresponding first 3 and second 4 comparison elements. One of them determines the maximum, and the other the minimum permissible values of the counter 2 information symbols. The boundary values are determined based on the known number of information symbols in the observation interval. The first 3 and second 4 comparison elements are polled by a signal from the output of the chronizer 7. The same signal, delayed by the time of the first 3 and second 4 comparison elements and the second comparison unit 12, is reset for counters 2 information symbols. If the number of information symbols in any counter 2 does not fit into the permissible limits, then at the output of the corresponding first 3 or second 4 comparison elements, a signal appears indicating poor channel quality.

Errors in communication channels can be: of two types: insertion type (transition O to 1) and type of disappearance (transition 1 to 0). If these two types of errors are equally likely to occur, a situation may occur when insertion type errors will be balanced by the same number of errors such as loss.

To identify these situations, the properties of a signal with time-frequency modulation are used. Such a signal is characterized by a constant number of units at each cycle of its transmission. The proposed analyzer can also be used for signals in which the number of units per cycle lies within certain limits.

The counter 10 of the number of characters determines: based on the signals from the selectors 1 pulses in duration, the number of information pulses. Per cycle. The output of the counter 10 is connected to the first input of the first comparison unit 11, which determines the minimum maximum permissible values of the counter 10. The boundary values of the counter 10 are determined based on the known number of information symbols at each clock cycle of the signal. The interrogation of the first comparison unit 11 is carried out by a signal from the additional output of the chroniser 7. The same signal, delayed by the additional delay element 9 for the time required for the operation of the unit 11 and the zeroing of the cell of the memory unit 14, resets the counter 10 of the number of characters and increases by one unit of numbers, stored in cells

78348 memory block 14. If the number of information symbols received at the input of block .11 does not fit into acceptable limits, then a signal is supplied to the input of error counter 13 and to the second input of block 14.

The memory unit 14 operates as follows.

At the beginning of the analysis, all its cells are zeroed. When a signal arrives at the first input of block 14, i.e. at each step of signal reception, there is an increase by one unit of numbers stored in all cells of block 14. When the signal first appears from the output of the first comparison block 11, the first input of block 14 is reset to the second input of block 14. Thus, further in the first cell of block 14, the clock is counted from the moment the error was detected. The next time the signal appears at the second input of block 14, the second cell is zeroed, and so on. After zeroing the last cell, the next time the first cell will be reset to zero. Therefore, in the cells of block 14 contains a sequence of lengths of error-free intervals.

The signal from the output of the first comparison unit 11 is fed to the input of an error counter 13, which accumulates the number of errors at each clock cycle of the signal. The output of the error counter 13 is connected to the first input of the second comparison unit, which determines the maximum and minimum acceptable values of the error counter 13.

Polling of the second block 12 comparison is performed by the same signal from the output of the chronizer 7 as the survey of the first 3 and second 4 elements of comparison. The same signal delayed for the duration of the first 3 and second 4 elements of comparison and. block 12, the error counter is reset. If the number of errors does not fit into the permissible limits, a signal appears at the output of the second comparison unit 12. The signals from the outputs of the first 3 and second 4 comparison elements, and the second comparison unit 12 are fed to the inputs of the OR element 6, the output of which produces a signal characterizing the quality of the communication channel.

Claims (1)

Formula of the invention The analyzer of the quality of the communication channel according to ed. St. No. 743214, due to the fact that, in order to expand functionality by analyzing η-band signals with time-frequency modulation, a frequency distributor, n-1 additional pulse selectors for duration, n-1 additional counters of information symbols, n-1 additional first comparison elements *, n-1 additional second comparison elements, a memory unit for error-free interval lengths and an additional delay element connected in series, a counter of the number of characters, the first comparison unit , an error counter and a second comparison unit, while the output of each additional pulse selector in duration, the input of which is connected to the corresponding output of the frequency distributor through the corresponding additional counter of information symbols, is connected to the first inputs of the corresponding additional first and second comparison elements, the outputs of which are connected to the corresponding inputs of the OR element, the corresponding input of which is connected to the 'output of the second comparison unit, whose second input is connected to by the second inputs of the additional first and second comparison elements and with the output of the chroniser, the additional output of which is connected to the clock input of the frequency distributor, to the second input of the first comparison unit and to the input of the additional delay element, the output of which is connected to the first input of the memory unit of error-free intervals, second input which is connected to the signal input of the error counter, the reset input of which is connected to the reset inputs of additional counters of information symbols and the counter of information symbols oxen, the signal inputs of which are connected to the corresponding inputs of the counter of the number of characters, and the pulse selector input is connected in duration to the corresponding output of the frequency distributor, the signal input of which is the input of the communication channel quality analyzer.