SU1107308A1 - Information transmission system with adaptive differential pulse-code modulation with compression of predicition error signal - Google Patents

Abstract

1. COMMUNICATION SYSTEM WITH ADAPTATION a multiplexer, the second input of which is connected to the second output of the filter-analyzer through the prediction error signal encoder, and on the receiving side connected demultiplexer, adaptive delta module, low pass filter, sampling frequency expander, spectrum equalizer, filter synthesizer and digital-to-analog converter; the second output of the demultiplexer is connected to the second input of the filter synthesizer, o f l and that which, in order to increase throughput. on the transmitting side, a constant memory block and a serially connected distortion value calculator are inserted, a control block and an index encoder whose output is connected to the third multiplexer input, and the second input of the index encoder is connected to the first output of the constant memory block, the second output of which is connected with the first input of the block for calculating the magnitude of the distortion, the second input of which is connected to the third output of the filter-analyzer, and at the receiving side a chain of serially connected index decoder and a block are entered and a memory that is connected between the third output of the demultiplexer and the third input of the filter synthesizer. 2. The system of claim 1, wherein there is a block for calculating the distortion value, contains the first and second memory registers, ot4 the corresponding outputs of which are connected to the inputs of the adder through multipliers, the output of which is ch1 calculating the amount of distortion, wherein the inputs of the first and second memory registers are the corresponding 09 inputs of the block for calculating the amount of distortion. 3. The system of claim 1, wherein the control unit comprises an error signal sampling and storage unit and a comparator, the first input of which, being the input of the control unit, is connected to the first loop of the error signal sampling and storage unit, block output

Description

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1107308 With the second input of the comparator.

The invention relates to radio engineering and communications and can be used to transmit telephone signals. The known information transmission system with adaptive differential pulse-code modulation with compression of the prediction error signal contains on the transmitting side serially connected analog-digital converter, filter analyzer, low-pass filter, sampling frequency compressor, adaptive delta-modulator and multi plexer 1. The disadvantage of this system information transmission with adaptive differential pulse code modulation is low bandwidth due to redundancy information sbderzhascheys signals in the linear prediction. The closest to the present invention is an information transmission system with adaptive differential pulse-code modulation with compression of a prediction error signal comprising a serially connected first low-pass filter, an analog-to-digital converter, an analyzer filter, a second low-pass filter, a sampling frequency compressor, on the transmitting side. adaptive delta modulator and multi. plexer, the second input of which is connected via the encoder of the prediction error signal to the second output of the filter analyzer of the torus, and on the receiving side there are serially connected demultiplexer, adaptive delta demodulator, low pass filter, sampling frequency expander, spectrum equalizer, filter synthesizer and digital-analogue the converter, the second output of the demultiplexer through the decoder of the prediction error signal is connected to the second input of the filter synthesizer 121. A disadvantage of the known information transmission system with An obvious differential pulse code modulation is the low transmission capacity of the transmission path. The purpose of the invention is to increase throughput. To achieve this goal, the information transmission system with adaptive differential pulse code modulation with compression of the prediction error signal contains the serially connected first low-pass filter, analog-to-digital converter, analyzer filter, second low-pass filter, sampling frequency compressor, adaptive on the transmitting side. a delta modulator and a multiplexer, the second input of which is connected to the second output of the filter analyzer through the prediction error signal encoder, and The serial side of the serially connected demultiplexer, adaptive delta demodulator, low pass filter, sampling rate expander, spectrum equalizer, filter synthesizer and digital to analog converter, the second output of the demultiplex ea through the decoder of the prediction error signal is connected to the second input of the filter synthesizer, on the transmitting side fixed memory unit and series-connected distortion value calculator, control unit and index encoder, the output of which is connected to one-third named after the multiplexer input, and the second input of the index coder is connected to the first output of the permanent memory unit, the second output of which is connected to the first input of the distortion calculator, the second input of which is connected to the third output of the analyzer filter, and on the receiving side connected index decoder and memory block, which is connected between the third output of the demultiplexer and the third input of the filter synthesizer.

Moreover, the distortion value calculating unit contains the first and second memory registers, the corresponding outputs of which are coupled to the inputs of the adder, the output of which is the output of the distortion calculation unit, and the inputs of the first and second memory registers are the corresponding inputs of the distortion calculation unit .

In addition, the control unit contains an error signal sampling and storage unit and a comparator, the first input of which is the input of the control unit is connected to the first input of the sample signal and the error signal storage unit, and the comparator output, which is the output of the control unit, is connected to the second input block sampling and storage of the error signal, the output of which is connected to the second input of the comparator.

The drawing shows a structural electrical circuit of an information transmission system with adaptive differential pulse code modulation with compression of a prediction error signal.

The system contains on the transmitting side a first lowpass filter 1, an analog-to-digital converter 2, an analyzer filter 3, a second lowpass filter 4, a sampling rate copressor 5, an adaptive delta modulator 6, a multiplexer 7, a prediction error signal encoder 8, block 9 calculate the distortion value, containing the first 10 and second 1 memory registers, multipliers 12, adder 13, control unit 14, containing error signal sampling and storage unit 15 and comparator 16, index coder 17, permanent memory unit 18, and the receiving side of the memory tiplekser 19 ,. adaptive delta demodulator 20, low pass filter 21, sampling frequency expander 22, spectrum equalizer 23, filter synthesizer 24, digital-to-analog converter 25, prediction error decoder 26, index decoder 27, and memory block 28.

The system works as follows.

Original speech signal after low pass filtering in the first

the filter 1 and the conversions in the analog-digital converter 2 are fed to the input of the filter analyzer 3, where the linear prediction coefficients and the prediction error energy are calculated, and the excitation function (prediction error) is generated. From the first output of the filter-analyzer-3, the generated signal of the excitation function passes through the second filter 4 and its low-frequency part is fed to the input of the compressor 5, where the sampling rate decreases to reduce the transmission rate. After conversion in adaptive delta modulator 6, the modulated low-frequency component of the excitation function is fed to the first input of multiplexer 7.

The 3 values of the prediction error energy after encoding in the encoder 8 obtained in the filter-analyzer are fed to the second input of the multiplexer 7. The linear prediction signals from the third output of the filter-analyzer are input to block 9, to the other input of which code words are sent from block 18 most powerful combinations of coefficients; linear prediction. For each pair of words stored in the first 10 and second 11 memory registers, the distortion value is measured by bitwise multiplying in multipliers 12 and summing in adder 13. Block 14 selects the minimum value of distortion by means of a comparator 16 and block 15. In the encoder 17, the index value of the codeword corresponding to the minimum value of the distortion; Ne is encoded by the signal from the JTopa 16 and is fed to the third input of the multiplexer 7.

The incoming signal to the receiving part is processed in the demultiplexer 19, where the modulated low-frequency component of the excitation function, transmitted to the adaptive delta-demodulator 20, the prediction error energy signal supplied through the decoder 26 to the second input of the filter-synthesizer 24, and the code are separated. the index of the codeword corresponding to the minimum value of the distortion value that is decoded in the decode. 27. and from block 28, the corresponding codeword is selected, which is fed to the third input of the filter synthesizer 24, to the first input of which an excitation function signal is fed — reconstructed in filter 21, expander 22 and equalizer 23. In filter synthesizer 2D, the original digital signal is restored, which after conversion

in a digital-to-analog converter 25 is provided to a recipient.

The use of the invention allows to increase the communication channel capacity by reducing the redundancy of the transmitted information, which will increase the possible number of transmitted channels by up to 25%.

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Claims (3)

1. INFORMATION TRANSMISSION SYSTEM WITH ADAPTIVE DIFFERENTIAL PULSE-CODE MODULATION WITH COMPRESSION OF THE SIGNAL OF THE FORECAST, containing 'on the transmitting side a first low-pass filter, a frequency converter, an analog-digital digital filter, an analog-to-digital converter, a filter-to-digital converter, an analog-to-digital converter, a filter-to-digital converter, a filter-to-analog converter, a filter-to-digital converter, a filter-to-digital converter, a filter-to-analog converter, a filter-to-digital converter, a filter-to-analog converter, a filter-to-analog converter, a filter-to-digital converter, a filter-to-analog converter, a filter-to-digital converter, a filter-to-analog converter, a filter-to-digital converter, a filter-to-analog converter, a filter-to-analog converter, a filter-to-analog converter, a filter-to-digital converter, a filter-to-analog converter, a filter-to-digital converter and a filter-to-digital converter , the second input of which is connected through the encoder of the prediction error signal to the second output of the filter analyzer, and in series on the receiving side a demultiplexer, an adaptive delta demodulator, a low-pass filter, a sampling frequency expander, a spectrum equalizer, a filter synthesizer and a digital-to-analog converter, the second output of the demultiplexer through a prediction error decoder connected to the second input of the filter synthesizer, revealing that, in order to increase the throughput abilities, on the transmitting side there is a read-only memory block and a series-connected distortion value calculation unit, a control unit and an index encoder, a cat output The second input is connected to the third input of the multiplexer, and the second input of the index encoder is connected to the first output of the read-only memory block, the second output of which is connected to the first input of the distortion calculation unit, the second input of which is connected to the third output of the filter analyzer, and a circuit is introduced on the receiving side from series-connected index decoder and memory block, which is connected between the third output of the demultiplexer and the third input of the filter-synthesizer. 2. The system according to claim 1, characterized in that the distortion value calculation unit contains first and second memory registers, the corresponding outputs of which are connected via inputs to the inputs of the adder, the output of which is the output of the distortion value calculation unit, the inputs of the first and the second memory registers are the corresponding inputs of the distortion amount calculation unit. 3. The system according to claim 1, characterized in that the control unit comprises an error signal sampling and storage unit and a comparator, the first input of which, which is the control unit input, is connected to the first input of the error signal sampling and storage unit, and the comparator output, which is the output control unit, connected to the second input! block sampling and storing the error signal, the output of which is connected to the second input of the comparator.