FR2639779A1 - DEVICE FOR ENCODING AND DECODING SOUND BROADCAST SIGNALS - Google Patents

Abstract

The invention relates to a device for encoding and decoding broadcast signals comprising an encoder comprising as input a low-pass filter 1 and in cascade an analog-to-digital converter 2, and a code converter 6, a pulse generator. synchronization 21 being connected to the synchronization inputs of converters 2, 6, and a decoder comprising a code converter 29, a digital-to-analog converter 32 and at output a low-pass filter 33, a synchronization pulse generator 44 having an output 48 connected to the synchronization input of the digital-analog converter 32. According to the invention, the device comprises an encoder and a decoder, the assembly of which, by introducing a band coding of the broadcasting signals in the spectral domain taking into account the masking effect in the critical hearing bands, allows the speed of the digital stream of the individual broadcasting channel to be reduced while preserving nt the high quality of reproduction during decoding.

Description

"DEVICE FOR CODING AND DECODING

SOUND BROADCAST SIGNALS "

  The present invention relates to information transmission techniques, and more particularly to coding and

  decoding sound broadcasting signals.

  The invention is intended for use in digital systems for transmission, recording, storage and playback of acoustic signals, in digital broadcasting, multifunctional link systems, in broadcast signal transmission systems digital terrestrial and spatial as well as in the digital sound support systems of television. The most widely used are coding and decoding devices for sound broadcasting signals using pulse code modulation, referred to as instant compression MIC (J. Bellami "Digital Telephony", 1986, "Radio i sviaz", (Moscow ), p.116). Such devices may be part of the equipment used to transmit satellite broadcasting programs, as well as equipment for the organization of digital terrestrial transmission channels for sound broadcasting programs. These devices include an encoder and a decoder. The encoder includes, cascaded, a channel low-pass filter, a compressor and an analog-to-digital converter whose output serves as an output to the encoder. The decoder

  includes, cascading, a digital converter-

  analog, an expander and a low-pass filter, the input of the decoder being constituted by that of the digital-to-analog converter. The use in these devices of a compressor and an expander makes it possible to increase the quantization step with raising of the level of the input signal and thus to maintain, at quantization, the signal / noise ratio at a level at which the noise is practically

imperceptible to the listener.

  In the device described, a ten-bit analog-to-digital converter is used to organize a high quality transmission channel, the compression of the signals being carried out by analog devices and the sampling frequency of the signal being 32 kHz; therefore, at the output of the encoder, the speed V of the digital stream is equal to:

V = 10 x 32 = 320 kbit / s.

  There are devices for encoding and decoding sound broadcasting signals ("Electrosviaz", No. 7, 1980, (Moscow), AN Golubev et al., "Apparatus for the digital transmission of sound broadcasting signals", p.6) using a PCM with instantaneous compression, which differ from the devices described above by the use of a digital compressor. The readings of the compressed signal in these devices are encoded by a 12-bit linear code. The sampling frequency in time is also equal to 32 kHz, so that at the output of the encoder, the speed V of the digital stream is equal to:

V = 12 x 32 = 384 kbit / s.

  that is to say, 20% larger than in the devices described previously. By increasing the speed of the digital stream, it is possible to improve the quality of the reproduced sound signal, which is confirmed by the results of the examinations. The sound reproduced in these devices is close to the natural sound, which is why the number of 12 bits for the coded word (or code) of reading is chosen for encoding signals by instantaneous compression PCMs. Such

  number of bits is characteristic of known systems.

  Compared with the equipment using the instantaneous PCM modulation, the lower speed of the digital stream of the individual sound broadcasting channel is provided by an adaptive differential PCM modulation. There are devices for coding and decoding sound broadcasting signals

  ("Electrosviaz" n, 1982, M. V. Guitlits, S.V.

  Thcetkin, "Using adaptive differential PCM modulation for analog-to-digital conversion of broadcast signals", p. 58) in which the signal is digitized by an encoder, and a decoder performs its inverse conversion. The encoder input block is a channel low pass filter. Its output is connected to a signal level adjustment block whose output signal drives a non-inverting input of an operational amplifier operating in differential mode and connected to a pulse amplitude modulator. The output of the pulse amplitude modulator is connected to the input of the analog-to-digital converter whose output serves as an output to the device. The encoder also has prediction and control circuits. The digital signal, from the encoder output, drives the input of the prediction circuit whose input block is a digital-to-analog converter where the digital signal is converted into an analog signal, whose

  average is made in an interpolator.

  The prediction signal formed drives the inverting input of a differential amplifier whose output provides a signal proportional to the difference between the input signal of the amplifier and the prediction signal. This differential signal goes through an amplitude modulation block

  pulses and attacks an analog converter-

  numeric o it is sampled in level and is converted into a binary code. The control circuit

  also includes an analog converter

  digital. The analog signal obtained at its output is rectified, integrated, and drives the corresponding input of a block of adjustment of the signal level of the encoder. This

  signal controls the transfer coefficient of the encoder.

  In the decoder, the binary code is subjected to a logical conversion in a logical block on which are

  connected, cascaded, a digital converter-

  analogue, an integrator, a low-pass filter and a signal level adjustment block. The transfer coefficient control circuit of the signal level adjustment block includes, cascaded, a digital-to-analog converter, a rectifier, and an integrator whose output is connected to the corresponding input of the adjustment block. At the low levels of the differential signal, the transfer coefficient of the decoder signal level adjustment block is maximum, and the transfer coefficient in the block of the signal level adjustment in the encoder is minimal, which ensures a higher quantization. precise differential signal in the absence of adaptation. At the maximum level of the differential signal, the transfer coefficient of the signal level adjustment block in the decoder is minimal, and in the signal level adjustment block in the encoder the

transfer is maximum.

  This device makes it possible to transmit the sound broadcasting signals in a frequency band of 15 kHz at a speed of the digital stream of 256 kbit / s, which is significantly lower than the speed in the apparatus using the PCM modulation at instant compression. Studies of the qualitative indices of the coding and decoding device with an adaptive differential MIC have demonstrated, on examining the quality of the sound signal, that for the signals representing the voice of a presenter, the light music, the literary reading the deformations do not exceed 10 to 15%. Distortions are more noticeable for signals such as piano, violin, symphony and chamber music, where they are 25 to 30%. Thus, the quality of the differential 256 kbit / s adaptive 256 kbit / s adaptive modulation modulation encoder is poorer than that of the instantaneous compression modulated PCM encoder where the distortions are imperceptible to the listener. This is why adaptive differential MIC encoders are only used for voice compression when there are no stringent requirements for the fidelity of their reproduction, as in the case of coding of

sound broadcasting.

  There is a device for coding and decoding sound broadcasting signals with floating point by blocks (quasi instantaneous compression) (The Radio and Electronic Engineering,

  v.50, No. 10, 1980, C.R.Caine, A.K. English, J.M.

  O'Clearey, "NICAM-III: near-instantaneously companded digital transmission system for high-quality sound programs", pp. 520, 529). The encoder of this device comprises, cascaded, a low-pass filter whose input serves as input to the encoder, an analog-digital converter and a code converter whose output serves as an output to the encoder, as well as a synchronization pulse generator whose output is connected to the synchronization inputs of the analog-to-digital converter and the

  code converter. The analog converter-

  digital performs the conversion of the analog signal in digital form by linear PCM modulation, and the sampling frequency of the continuous signal in time equal to twice the cutoff frequency of the low-pass filter is chosen, according to the standards.

existing, equal to 32 kHz.

  The number of coding bits of the readings, in the different variants of the systems, varies from 14 to 16 bits depending on the dynamic range desired for the reproduction of the signal. The code converter converts the 16-bit code into a floating point block code, the mantissa being encoded by a 10-bit word including a sign bit and the exponent being encoded by a 3-bit word. The length of a floating point block block is 32 reads. The exponent is determined from the reading of the absolute block in absolute value and this exponent value is used for a new

coding readings of the given block.

  The decoder of the known device comprises, cascaded, a code converter whose input serves

  input to the decoder, a digital converter

  analogue and a low-pass filter whose output serves as an output to the decoder. The decoder also comprises a synchronization pulse generator whose input is joined to the input of the code converter and the output is connected to the synchronization inputs of the digital-to-analog converter.

and the code converter.

  The code converter realizes the conversion of the floating point code into 16-bit code words which, in code

  parallel, are provided on the digital converter-

  analog. Restored readings of sound broadcast signals arrive in a low-pass filter

which smooths them in time.

  The speed of the digital stream at the coder output of the individual block-floating sound channel is 323 kbit / s, ie 20% less than the output of the coding device. broadcast signals

  sound using an instant compression MIC.

  In this case, the sound quality of the signal output at the output of the decoder is not worse than at the output of the 12-bit decoder of the coding devices of the sound broadcasting signals using an instantaneous compression MIC. This is achieved by the fact that at floating block-code the quantization noise masking effects are taken into account in the coding time interval of the

  block with constant exponent value.

  Nevertheless, the speed of the digital flux at the output of the encoder remains high from the point of view of the efficient use of the digital transmission channel, that is to say that for the transmission of such a digital signal, it is necessary to have a way of

high capacity transmission.

  The aim of the invention is to create such a device for encoding and decoding sound broadcasting signals, including the mounting of the encoder and the decoder, by introducing a band coding of the sound broadcasting signals into a zone of sound. spectrum taking into account the masking effect in the critical bands of human hearing, would reduce the speed of the digital stream of the individual sound broadcasting channel while maintaining a high

  quality of its reproduction at decoding.

  The problem posed is solved by a device for encoding and decoding sound broadcasting signals, comprising: an encoder comprising, cascaded, a low-pass filter whose input serves

  input to the encoder and an analog converter-

  digital, as well as a code converter electrically connected to the analog-to-digital converter, a synchronization pulse generator having an output connected to synchronization inputs of the analog-to-digital converter and the code converter; and a decoder comprising a code converter, and, cascaded, a digital-to-analog converter electrically connected to the code converter and a low-pass filter whose output serves as an output to the decoder, a synchronization pulse generator having an output connected to the synchronization input of the digital-to-analog converter; characterized in that for encoding and decoding monophonic sound broadcasting signals, the encoder comprises: a buffer memory block on the respective inputs of which are connected, bit by bit, the outputs of the analog-to-digital converter, while inputs clock pulses and clock cycles of the buffer storage block are connected to respective outputs of the synchronization pulse generator; a spectral conversion block of the sound broadcasting signals, whose information inputs are connected to the outputs of the buffer storage block, and clock cycle and clock pulse inputs are connected to the respective outputs of the a synchronization pulse generator, the outputs of the spectral conversion block of the sound broadcasting signals being connected, bit by bit, to the information inputs of the code converter; a control pulse shaper having sync inputs connected to the respective outputs of the sync pulse generator and its respective outputs are connected to control inputs of the code converter; a memory block containing the spectral component numbers of the critical bands of the hearing which has its control inputs connected to the respective outputs of the control pulse shaper and its outputs connected to the information inputs of the pulse shaper control unit, a synchronization input of the memory block containing numbers of the spectral components of the critical bands of the hearing being connected to the respective output of the synchronization pulse generator; a multiplexer which has its information inputs connected to the outputs of the code converter, and its control inputs connected to the respective outputs of the control pulse shaper, the synchronization inputs of the multiplexer being connected to the respective outputs of the generator synchronization pulses and the output of the multiplexer serving as an output to the encoder; and under these conditions, the decoder comprises: a demultiplexer whose input serves as an input to the decoder and is connected to the output of the multiplexer, the information outputs of the demultiplexer being connected to the respective inputs of the code converter and the one of its synchronization outputs being connected to the respective inputs of a synchronization pulse generator and the code converter; a buffer memory block which has its information inputs connected, bit by bit, to the respective outputs of the code converter, and its synchronization inputs connected to respective outputs of the synchronization pulse generator and the demultiplexer; an inverse spectral conversion block of the sound broadcasting signals which has its information inputs connected, bit by bit, on the respective outputs of the buffer memory block, its synchronization inputs connected to the respective outputs of the synchronization pulse generator and the demultiplexer, and its outputs connected, bit by bit, to the respective inputs of the digital-to-analog converter; a control pulse shaper which has its synchronization inputs connected to the respective outputs of the demultiplexer and the synchronization pulse generator of which a suitable output is connected

26397 9

  on the synchronization input of the code converter, outputs of the control pulse shaper being connected to the respective control inputs of the code converter, as well as inputs of the demultiplexer and the buffer memory block; and a memory block containing the spectral component numbers of the critical bands of the hearing, which has its control inputs connected to the respective outputs of the control pulse shaper, its synchronization input to the corresponding output of the demultiplexer, and its outputs connected to the information inputs of the shaper

control pulses.

  The problem is also solved by a device for encoding and decoding sound broadcasting signals comprising: an encoder comprising, cascaded, a main low-pass filter whose input serves as an input to the encoder and an analog-to-digital converter main and a main code converter electrically connected to the main analog-to-digital converter, a synchronization pulse generator being connected to the synchronization inputs of the main analog-to-digital converter and the main code converter; and a decoder having a main code converter

  and, cascading, a digital converter-

  main analogue electrically connected to the main code converter and a main low-pass filter whose output serves as an output to the decoder, a synchronization pulse generator having an output connected to. the synchronization input of the main digital-to-analog converter; characterized in that, for coding and decoding stereo broadcast signals, the encoder includes, cascaded, an auxiliary low-pass filter whose input serves as an auxiliary input to the encoder, and an auxiliary digital-to-analog converter whose the synchronization input is connected to the respective output of the synchronization pulse generator, an arithmetic unit whose information inputs are respectively connected, bit by bit, to the outputs of the main and auxiliary digital analog converters and its synchronization input is connected to the respective output of the synchronization pulse generator, a block of digital filters which has its information inputs connected, bit by bit, to the respective outputs of the arithmetic unit, and its synchronization input connected to the output respective synchronous pulse generator, a signal conversion block carrying the information on the broadcast stereo signal, having 2m groups of information inputs, om = 1 ... 24, connected, bit by bit, respectively, on outputs of the digital filter block, and a group of bitwise connected information inputs on respective outputs of the arithmetic unit, as well as synchronization inputs which are connected to respective outputs of the synchronization pulse generator, auxiliary code converters whose inputs bits are bit-wise connected to outputs of the signal converting block carrying information on the broadcast stereo signal, the synchronizing inputs of the auxiliary code converters being connected to the respective outputs of the signal generator. synchronization pulses, a multiplexer which has its information inputs connected, bit by bit, on outputs of the main code converter, its inputs synchronization pulses connected to respective outputs of the synchronization pulse generator, the output of the multiplexer serving as an output to the encoder, each of the auxiliary code converters having two groups of outputs connected to respective information inputs of the multiplexer; as well as cascading with the arithmetic unit and said conversion block, a buffer memory block which has a group of information inputs connected, bit by bit, to the respective output of the arithmetic unit and a second group of information inputs connected, bit by bit, to the respective output of the signal conversion block carrying the information on the broadcast stereo signal, the synchronization inputs of the buffer memory block being connected to the respective outputs of the synchronization pulse generator, and a spectral conversion block of the sound broadcasting signals with its bit-by-bit information inputs connected to the outputs of the buffer memory block, its synchronization, clock and clock cycles connected to the respective outputs of the synchronization pulse generator, the outputs of the spectral conversion block of the sound broadcasting signals being connected, bit by bit, to the information inputs of the main code converter; the encoder also comprising a control pulse shaper which has its synchronization inputs connected to the respective outputs of the synchronization pulse generator, some of its outputs respectively connected to control inputs of the main code converter, and outputs on the inputs of the multiplexer; and a memory block containing the spectral component numbers of the critical bands of the hearing which has its control inputs connected to the respective outputs of the control pulse shaper and its outputs connected to the shaper information inputs. control pulses, the synchronization input of the memory block containing the spectral component numbers of the critical bands of the hearing being connected to the respective output of the synchronization pulse generator; and in that the decoder comprises: a demultiplexer whose input serves as an input to the decoder and is connected to the output of the multiplexer of the encoder, the respective outputs of the demultiplexer being connected to the information inputs of the main code converter of the decoder and one of its synchronization outputs being connected to the respective inputs of the synchronization pulse generator and the decoder main code converter; a first buffer storage block whose information inputs are connected, bit by bit, to the respective outputs of the decoder main code converter and its synchronization inputs connected to the respective outputs of the synchronization pulse generator; an inverse spectral conversion block of the sound broadcasting signals which has its information inputs connected, bit by bit, to the respective outputs of the first buffer storage block, its synchronization inputs connected to the respective outputs of the pulse generator of synchronization; a control pulse shaper having its synchronization inputs connected to the respective outputs of the demultiplexer and the synchronization pulse generator and an appropriate output connected to the synchronization input of the decoder main code converter; control pulse shaper being respectively connected to the control inputs of the main code converter of the decoder and the demultiplexer; a memory block containing the spectral component numbers of the critical bands of the hearing which has its control inputs connected to the respective outputs of the control pulse shaper, its synchronization input connected to the respective output of the pulse generator synchronization and its outputs connected to the information inputs of the control pulse shaper; m auxiliary code converters each of which has two information inputs connected to the respective outputs of the demultiplexer, the synchronization inputs of each m auxiliary code converters being respectively connected to outputs of the synchronization pulse generator and the demultiplexer; a stereophonic signal reproduction block which has its synchronization input connected to the respective output of the synchronization pulse generator; a block of digital filters whose synchronization input is connected to the respective output of the synchronization pulse generator and its (m + 1) outputs and the outputs of each of the m auxiliary code converters being connected, bit by bit, on respective inputs of the stereophonic signal reproduction block; a second buffer memory block which has its information inputs connected, bit by bit, on the outputs of the inverse spectral conversion block of the sound broadcasting signals, and its synchronization inputs respectively connected to the outputs of the pulse generator and the demultiplexer, the outputs of an output group of the second buffer storage block being connected, bit by bit, to the respective inputs of the digital filter block, and the outputs of another group of outputs being connected, bit by bit on the respective inputs of the stereophonic signal reproduction unit; and, cascaded, an auxiliary digital-to-analog converter, and an auxiliary low-pass filter whose output serves as an auxiliary output to the decoder, the outputs of a group of outputs of the stereophonic signal reproduction block being connected, bit by bit, bit, on the information inputs of the main digital-to-analog converter, and the outputs of its other group of outputs being connected, bit by bit, to the information inputs of the auxiliary digital-to-analog converter, whose synchronization input is connected to the respective output

  of the synchronization pulse generator.

  The claimed invention makes it possible to halve the speed of the digital stream of a monophonic signal of high quality sound broadcasting compared to the PCM modulation with instantaneous compression currently used, and to divide by 1.4 the speed of the digital stream. broadcast stereo digital signal versus the transmission method where the left and right stereo channels are encoded and transmitted independently of each other. The use of the present invention makes it possible to transmit in the primary standard digital stream of 2048 kbit / s twelve monophonic digital programs, ie eight stereophonic sound broadcasting programs of the best quality class instead of six monophonic programs transmitted at present. . This result is of the utmost importance for the spatial distribution systems of sound broadcasting programs. The cost of transmission is very high. In addition to this, the use of the claimed invention in systems for transmitting radio sound signals can significantly reduce the

  frequency band occupied by the signal.

The invention will stand out better from

  following description of concrete examples of execution

  schematically in the accompanying drawings in which: - Figure 1 shows a block diagram of an encoder and a decoder for monophonic sound broadcasting signals, according to the invention; FIG. 2 represents a block diagram of an encoder code converter for monophonic sound broadcasting signals, according to the invention; FIG. 3 represents a block diagram of an encoder control pulse shaper for monophonic sound broadcasting signals, according to the invention; FIG. 4 represents a block diagram of a memory block containing the numbers of the spectral components of the critical bands of the sound encoder for monophonic sound broadcasting signals, according to the invention; FIG. 5 represents a block diagram of an encoder synchronization pulse generator for monophonic sound broadcasting signals, according to the invention; FIG. 6 represents a block diagram of a code converter of the decoder for monophonic sound broadcasting signals, according to the invention; FIG. 7 is a block diagram of a timing pulse generator of the decoder for monophonic sound broadcasting signals according to the invention; FIG. 8 represents the timing diagrams explaining the operation of the encoder and the decoder for monophonic sound broadcasting signals, according to the invention; FIG. 9 represents a block diagram of an encoder and a decoder for broadcasting stereophonic signals, according to the invention; FIG. 10 represents a block diagram of an arithmetic unit of the coder for stereophonic broadcasting signals, according to the invention; FIG. 11 represents a block diagram of a digital filter block of the encoder for stereo broadcasting signals, according to the invention; FIG. 12 is a block diagram of a signal conversion block carrying information on the stereophonic signal of the coder for stereophonic broadcast signals, according to the invention; FIG. 13 represents a block diagram of a buffer storage block of the encoder for stereophonic broadcast signals, according to the invention; FIG. 14 represents a block diagram of a buffer storage block of the decoder for stereophonic broadcast signals, according to the invention; FIG. 15 represents a block diagram of a stereophonic signal reproduction block of the decoder for stereophonic broadcasting signals, according to the invention; FIG. 16 represents the chronograms explaining the operation of the digital filter block of the encoder for stereo signals of

broadcasting according to the invention.

  The claimed device for encoding and decoding sound broadcasting signals includes

  two parts: an encoder and a decoder.

  The encoder for monophonic sound broadcasting signals comprises, cascaded, a low-pass filter 1 (FIG. 1), whose input serves

  input to the encoder, and an analog converter

  2, whose outputs are connected, bit by bit, to the respective inputs of a buffer memory block 3. The outputs of the buffer memory block 3 are connected to the information inputs of a spectral conversion block 4 sound broadcasting signals whose outputs are connected, bit by bit, to the information inputs 5 of a code converter 6. Control inputs 7, 8 of the converter 6 are connected to the respective outputs of a shaper 9. On the inputs 10 and 11 of the shaper 9, are connected the outputs of a memory block 12 containing the spectral component numbers of the critical bands of the hearing, whose control inputs 13, 14 , 15 are connected to the respective outputs of the

shaper 9.

  The encoder also comprises a multiplexer 16 on the information inputs of which are connected outputs 17, 18 of the converter 6. The control inputs 19, 20 of the multiplexer 16 are connected to the respective outputs of the shaper 9. In addition, the encoder comprises a synchronization pulse generator 21 having an output 22 connected to the synchronization inputs of the digital analog converter 2, the buffer storage block 3, the spectral conversion block 4, the converter 6 and the multiplexer 16. An output 23 of the generator 21 is connected, respectively, to the synchronization inputs of the buffer memory block 3, the spectral conversion block 4, the shaper 9, the memory block 12 and the multiplexer 16. An output 24 of the generator 21 is connected to the respective synchronizing input of the shaper 9, and an output 25 on the respective inputs of the shaper 9 and the multiplexer 16, whose output serves as an output to the encoder. The decoder for monophonic sound broadcasting signals comprises a demultiplexer 26 whose input serves as an input to the decoder and is connected to the output of the multiplexer 16. The outputs 27, 28 of the demultiplexer 26 are connected to the information inputs of the decoder. a code converter 29. The decoder also comprises, cascaded, a first buffer storage block 30 whose information inputs are connected, bit by bit, on the outputs of the code converter 29, a spectral conversion block 31 inverse of the signals of

  sound broadcasting, a digital converter-

  analog 32 and a low-pass filter 33 whose output serves as an output to the decoder. In addition, the decoder comprises a control pulse shaper 34 whose outputs 35, 36, 37, 38 are connected to the control inputs of the code converter 29. In addition, the output 38 is connected to the input of control of the first buffer storage block 30 and the outputs 35 and 36 are connected to the respective inputs of the demultiplexer 26. At the control inputs of the shaper 34 are connected outputs -39, 40 of an emitter block 41 containing the spectral component numbers of critical hearing bands whose control inputs are related to

outlets 42, 43 of the shaper 34.

  The decoder also comprises a synchronization pulse generator 44 whose input is connected to an output 45 of the demultiplexer 26 also connected to the respective inputs of the code converter 29 and the shaper 34. An output 46 of the demultiplexer 26 is connected to the respective inputs of the shaper 34, the memory block 41, the buffer memory block 30, and the inverse spectral conversion block 31. An output 47 of the generator 44 is connected to the synchronization inputs of the code converter 29 and the shaper 34 An output 48 of the generator 44 is connected, respectively, to the synchronization inputs of the buffer memory block 30, the inverse spectral conversion block 31 and the

  digital-to-analog converter 32.

  The low-pass filter 1 can be made according to a known arrangement ("Tekhnika sredstv sviazi", TRPA series, fasc 3, 1984, (Moscow), M. U. Bank, O.A. Klimova

  "Low Pass Filter for Digital Receiver", P. 90).

  As an analogue converter

  digital 2, one can use a microcircuit A2884 of the company "Motorola" used in the industry. The buffer memory block 3 can be made according to a known arrangement (B.F. Vysotsky, "Digital filters and signal processing devices using integrated circuits", 1984, "Radio i sviaz", (Moscow), p.56). As a spectral conversion block 4, it is possible to use a microcircuit, for example a Fourier processor, AM 29540, produced by the company

  "Advanced Micro Devices" used in the industry.

  The block diagram of the code converter 6 is shown in FIG. 2. It comprises a detector 49 of the exponent of the maximum element and a buffer storage block 50 whose inputs joined together serve as information input 5 to the code converter 6. The control input of the detector 49 serves as control input 7 to the code converter 6 and is connected to the respective output of the control pulse shaper 9 (Fig. 1) and its synchronization input is connected to the output 22 of the synchronization pulse generator 21 (FIG. 1). The outputs of the detector 49 (FIG. 2) are connected, bit by bit, to the respective inputs of a code register of the exponent 51. The control inputs of the register 51 serve as control inputs 7 and 8 to the converter of code 6 and are connected to the respective outputs of the

  control pulse shaper 9 (Figure 1).

  The synchronization input of the register 51 (FIG. 2) is connected to the output 22 of the synchronization pulse generator 21 (FIG. 1). The outputs of the register 51 (FIG. 2) serve as outputs 17 to the code converter 6 and are connected to the respective information inputs of the multiplexer 16 (FIG. 1), as well as to the respective group of information inputs of FIG. a floating point code encoder 52 (FIG. 2). The outputs of the encoder 52 serve as outputs 18 to the code converter 6 and are connected to the respective information inputs of the multiplexer 16 (FIG. 1). On another group of information inputs of the encoder 52 (FIG. 2) are connected, bit by bit, the outputs of the buffer memory block 50, the synchronization inputs of the encoder 52 and the block 50 being connected to the output 22 synchronization pulse generator

21 (Figure 1).

  The synoptic diagram of the control pulse shaper 9 is shown in FIG. 3. It comprises a pulse counter 53 whose outputs are connected, bit by bit, to a group of inputs of a comparator 54 whose inputs of another group of inputs serve as inputs 10 to the shaper 9 and are connected to the respective outputs of the memory block 12 (Figure 1). The output of the comparator 54, which is one of the outputs of the shaper 9, is connected to the control input 13 (FIG. 1) of the memory block 12. The shaper 9 (FIG. 3) also comprises, cascaded, pulse counters 55, 56, the combined inputs of the counters 53 and 55 and the input of the counter 56 serving as synchronization inputs to the shaper 9 and being, respectively, connected to the outputs 23, 24 and 25 of the generator of FIG. synchronization pulses 21 (FIG. 1). The output of the counter 55 (FIG. 3), being the output of the shaper 9, is connected to the control input 15 (FIG. 1) of the memory block 12. The outputs of the counter 56 (FIG. 3) are connected, bit by bit. bit, on a group of inputs of a comparator 57 whose inputs of another group of inputs serve as inputs 11 to the shaper 9 and are connected to the respective outputs of the memory block 12 (Figure 1). The output of the comparator 57 (FIG. 3) is connected to the control input 14 (FIG. 1) of the memory block 12 and to one of the inputs of a pulse counter 58 (FIG. 3) of which another input serves as a synchronization input to the shaper 9 and is connected to the output 25 of the synchronization pulse generator 21 (Figure 1). The output of the counter 58 (FIG. 3) is connected to an input 59 of a flip-flop 60, an input 61 of which is connected to the output of the comparator 57, and the output of the flip-flop 60 constitutes one of the outputs of the shaper 9 and is connected to the control input 19 (FIG. 1) of the multiplexer 16 and to the input of an inverter 62 (FIG. 3). The output of the inverter 62, being an output of the shaper 9, is connected to the control input 20 (FIG. 1) of the multiplexer 16. The shaper 9 (FIG. 3) also comprises a pulse counter 63 of which one input is connected to the output of the comparator 54 and the other, being one of the synchronizing inputs of the shaper 9, is connected to the output 24 of the synchronization pulse generator 21 (Figure 1). The output of the counter 63 (FIG. 3) is connected to one of the inputs of a flip-flop 64, another input of which is connected to the output of the comparator 54, and the output of the flip-flop 64 serves as an output for the shaper 9 and is connected to the control input 7 (Figure 1) of the code converter 6. The output of the counter 63 (Figure 3) is connected. in addition, on the inputs of a pulse counter 65 and a flip-flop 66 cascaded to one another, another input of the counter 65 constituting one of the synchronizing inputs of the shaper 9 and being connected to the output 24 of the synchronization pulse generator 21 (FIG. 1), and the output of the flip-flop 66 (FIG. 3) serving as an output for the shaper 9 and connected to the control input 8 (FIG.

1) of the code converter 6.

  The block diagram 12 of the memory block 12 containing the spectral component numbers of the critical bands of the hearing is represented in FIG. 4. It comprises a pulse counter 67, one of whose inputs serves as a control input 13 to memory block 12 and is connected to the respective output of the shaper 9 (Figure 1), while another input of the counter 67 (Figure 4) serves as a synchronization input to the memory block 12 and is connected to the output 23 (FIG. 1) of the synchronization pulse generator 21. The outputs of the counter 67 (FIG. 4) are connected, bit by bit, to the inputs of a fixed memory 68, the outputs serving as outputs to the memory block 12 and are connected to the inputs 10 (Figure 1) of the shaper 9. The memory block 12 (Figure 4) also comprises a pulse counter 69 whose inputs serve as control inputs 14 and the memory block 12 and are connected on the respective outputs of a shaper 9 (Figure 1). The outputs of the counter 69 (FIG. 4) are connected, bit by bit, to the inputs of a fixed memory 70 whose outputs serve as outputs to the memory block 12 and are connected to the inputs 11 (FIG.

shaper 9.

  The counters 67 and 69 can be realized thanks to integrated circuits of the series SN 7400, and the fixed memories 68 and 70 thanks to microcircuits

  of the MM 3600 series available in the industry.

  The synchronization pulse generator 21 (FIG. 5) comprises a crystal oscillator 71 on the output of which frequency dividers 72, 73, 74, 75 are connected whose outputs serve, respectively, as outputs 22, 23, 24, The crystal oscillator 71 can be made according to a known arrangement (LM Goldengerg, "Digital Devices Based on Integrated Circuits in Communication Technology", 1979, "Sviaz", (Moscow), p. ). The frequency dividers 72, 73, 74, 75 are made based on SN 7400 series meters available in the industry. The multiplexer 16 and the demultiplexer 26 (FIG. 1) are made according to a known arrangement (L.S. Levin, M.A. Plotkin, "Digital information transmission systems", 1982,

"Radio i sviaz", (Moscow), p.87).

  The code converter 29 of the decoder is produced according to the block diagram shown in FIG. 6. It includes an exponent code register 76 whose input serves as an information input to the code converter 29 and is connected to the input 27 (Fig. 1) of demultiplexer 26, and another input serves as control input to code converter 29 (Fig. 6) and is connected to output 37 (Fig. 1) of control pulse shaper 34, then a third input of the register 76 (Figure 6) is connected to the output 45 of the demultiplexer 26 (Figure 1). The outputs of the register 76 (FIG. 6) are connected, bit by bit, to the inputs of a comparator 77 whose output is connected to an input 78 of a register 79 and to one of the inputs of a counter. 80. The output of counter 80 is

  connected, bit by bit, to the inputs of the comparator 77.

  Two other inputs of the counter 80 and the register 79 are combined and serve as the synchronization input of the converter 29 connected to the output 47 (FIG. 1).

  synchronization pulse generator 44.

  The code converter 29 (FIG. 6) also comprises a mantissa code register 81, one of whose inputs serves as an information input to the code converter 29 and is connected to the output 28 (FIG. 1) of the demultiplexer 26. the other input of the register 81 (FIG. 5) being connected to the output 45 (FIG. 1) of the demultiplexer 26. A third input of the register 81 (FIG. 6) serves as control input to the code converter 29 and is connected on the output 36 (FIG. 1) of the control pulse shaper 34. An input of the register 79 is connected to a corresponding input of the counter 80 and serves as control input to the code converter 29 connected to the output 35 (FIG. 1) of the control pulse shaper 34. The outputs of an output group 82 (FIG. 6) of the register 81 are connected, bit by bit, to the inputs of the register 79, and an output 83 to one of the entries of a register 84 of which another entry serves as a com entry The outputs of the register 79 (FIG. 6) are connected, bit by bit, to a group of respective inputs of the register 84, and are connected to the output 38 (FIG. 1) of the control pulse shaper 34. whose outputs serve as outputs to the code converter 29 and are connected, bit by bit, to the information inputs of the buffer memory block 30 (FIG. 1). The registers 76, 79, 81 and 84 (FIG. 6), the comparator 77 and the counter 80 are made based on microcircuits of the SN 7400 series available in the industry. The buffer storage block 30 (FIG. 1) is produced in the same way as the buffer memory block 3. The inverse spectral conversion block 31 can be implemented by using a microcircuit identical to block 4 (FIG. 1). As the numerical digital converter 32, one can use the microcircuit A 2854 of the company "Motorola", available in the industry. The low-pass filter 33 is made according to a diagram identical to the diagram of the low-pass filter 1 of the encoder. The control pulse shaper 34 is produced in the same way as the shaper 9, the block 41 of the same

way that block 12.

  The structure of the synchronization pulse generator 44 is shown in FIG. 7. It comprises a frequency multiplier 85 whose input serves as an input to the generator 44 and is connected to the output 45 (FIG. 1) of the demultiplexer 26. The output of the multiplier 85 (FIG. 7) is connected to the inputs of the frequency dividers 86 and 87. The outputs of the dividers 86 and 87 serve, respectively, as outputs 47 and 48 to the generator 44. The frequency multiplier 85 is produced according to a known montage (IK Rizkin, "Multipliers and Frequency Divider", 1976, "Sviaz", (Moscow), 124). The frequency dividers 86 and 87 are based on SN 7400 series meters, available in the industry. FIG. 8 shows the chronograms of the signals explaining the operating principle of the device for coding and decoding monophonic sound broadcasting signals: a) sequence diagram of the coded words of the spectral components at the output of block 4 ( Figure 1) spectral conversion; to, t1 (FIG. 8a): respectively, start and end times of the coded words of the spectral components of the considered sample of N readings of the sound broadcasting signal; b, c, d, e) diagrams of the signals at the outputs of the shaper 9 (FIG. 1) of encoder control pulses connected to the inputs 7, 8 of the code converter 6 and to the inputs 19, 20 of the multiplexer 16; t2 and t3 (Fig. 8): respectively, start and end times of the pulse sequences which control the process of encoding the spectral components of a sample of N readings of the sound broadcast signal; f, g, h, i) diagrams of the signals at the outputs 37, 36, 35, 38 (FIG. 1) of the decoder control pulse shaper 34; t4 and t5 (FIG. 8): respectively, start and end moments of the pulse sequences which control the process of decoding the spectral components of a sample of

  N readings of the sound broadcasting signal.

  The claimed device for encoding and decoding monophonic broadcasting signals

  Sound works as follows.

  A sequence of readings of the sound broadcasting signal is decomposed into samples of N readings each. For each sample, the spectrum containing N components is calculated. The resulting components of the instantaneous spectrum are divided into twenty four frequency groups corresponding to twenty four critical bands of the hearing. The borders of these bands are. represented in Table 27.1 of the book "Ear as Information Receiver" by E. Zveker and R. Feldkeller, 1971, "Sviaz", (Moscow). In each group of twenty four frequency groups, a maximum spectral component in absolute value is selected. According to this spectral component, the value of the exponent of the block floating point code is chosen; then, the spectral components of the given frequency group are coded with this value of the exponent. The number of KM bits of the mantissa code is chosen to ensure the necessary value of the coding error of the maximum spectral component in the given frequency group. The number of bits Kp of the code of the exponent must ensure the possibility of recovery of the whole range of variations of the spectral component equal to sixteen bits, that is why Kp = 4 is chosen. In each group of frequencies, the errors encoding of the other lower spectral components at the maximum component level may exceed the given value because they are not perceived by hearing because of the masking effect within the critical hearing bands. The permissible value of the coding error of the maximum spectral component shall be 30 dB below the level of the component to be coded. In this case,

  Coding errors are not perceived by the auditor.

  In order to ensure a coding signal-to-noise ratio equal to dB, it is sufficient to have the words of mantissas

  encoded on five bits, that is, KM = 5.

  Thus, for the coding of a sample of N readings of the sound broadcasting signal, N.KM + 24Kp binary characters are required. The length of the sample N is chosen so that the interval T of the spectral analysis is approximately equal to the range of inertia of the hearing, that is to say that its value T = N / Fd = 30 ms, where Fd is the sampling frequency. At the sampling frequency Fd = 32 kHz in time, the sample length N = 1024. Therefore, for coding readings of a sample, 1024 x 5 + 24 x 4 binary characters are required. The repetition frequency of the samples is equal to Fd / N. That is why the speed V of the digital flux at the output of the encoder is: V = (Fd / N) (N.KM + 24Kp) = (32/1024) (1024 x 5 + 24 x 4) = = 163 kbits / s, i.e., less than half that in the PCM decoder with floating point

blocks.

  To restore the initial reading sequence from the coded words of the exponents and mantains of the spectral components, in the decoder, the reproduction of the spectral components is done by converting the floating point code in blocks into a fixed-point code; then, by inverse spectral conversion, the respective sample consisting of N readings of the sound broadcasting signal in the time domain is restored. As a spectral conversion, any known orthogonal transformation can be used: Fourier transformations, discrete cosine transformation, Adamar transformation, etc. The most preferable is the discrete cosine transformation because its use ensures the best

  quality of sound restored (reproduced).

  The encoder for monophonic signals

works as follows.

  The analog sound broadcasting signal drives the input of the low-pass filter 1 (FIG. 1) which limits the frequency band of the input signal to the higher frequency F = 15 kHz. Since the output of the low-pass filter 1, the signal drives the input of the digital analog converter 2 o is sampled the signal with the sampling frequency Fd in time equal to Fd = 32 kHEz, a quantization and a coding of the readings obtained by a 16-bit linear code. Formed in the analog-to-digital converter 2, the coded words of the readings arrive at the frequency Ft on the input of the buffer storage block 3 with capacity of 2N 16-bit coded words where N is the number of readings in a sample on which is based spectral analysis. The buffer memory block 3 delays the sequence of 2N / Fd s codewords in order to tune the output of the analog-to-digital converter 2 to the input of the spectral conversion block 4 which processes the blocks of N codewords. After accumulation in the buffer memory block 3 of N coded words corresponding to the first N readings of the sound broadcasting signal, they are read successively and sent to the input of the spectral conversion block 4 o

  the sequence spectrum of N reads is calculated.

  Thus, in the time interval at T = N / Fd, the current spectral analysis of the signal of

sound broadcasting.

  The output of the spectral conversion block 4 successively supplies the 16-bit coded words of the spectral components: coefficients of the discontinuous spectral conversion. The sample of N signal readings (in general, we choose N = 2s, os is the natural number 1, 2, s ...., because in this case the algorithm of the fast spectrum conversion is the most simple to perform) corresponds to N spectral decomposition coefficients arranged regularly on the frequency axis with a pitch / f = Fd / N. The first coefficient corresponds to the frequency fo = 0, and the last one to the frequency fN-! = Fd (1-1 / N). Thus, the spectrum of a sample of N readings of the sound broadcasting signal is defined by N number presented in the 16-bit linear code. The order of the sequence in the tenps of these numbers at the output of the spectral conversion block 4 is represented on the timing diagram (FIG. 8a), where the block of the 16-bit coded word is

represented by a rectangle.

  The code converter 6 (FIG. 1) performs the conversion of the 16-bit linear code of the spectral components into a floating point block code, that is to say in code used for a PCM floating point modulation ( almost instantaneous compression). The difference lies in the following fact: firstly, instead of a sequence of readings of the sound broadcasting signal made in time, there exists a sequence of its spectral components; secondly, the length of the block coded with a constant exponent value (scale of the coefficient) is variable and imposed by the signals attacking the control inputs 7 and 8 of the converter 6 from

  outputs of the control pulse shaper 9.

  The time diagrams of these signals are

  respectively shown in Figure 8b, c.

  The coded words of the spectral components arrive at the information inputs 5 (FIG. 1) of the code converter 6 by simultaneously driving the inputs of the detector 49 (FIG. 2) and the buffer memory block 50. In the block 50, they are the accumulation of the coded words (its capacity is equal to N) and their successive shift with the arrival of the next word. The detector 49 compares the arriving coded words, and chooses among them a coded word corresponding to the maximum spectral component in absolute value. The detector 49 extracts from this coded word the value of the exponent equal to the number of upper bits "O" of the coded word and forms the coded word of the exponent. When the detector 49 compares the necessary number of coded words, the input of the detector 49 serving as input 7 to the code converter 6 receives, from the output of the shaper 9 (FIG. 1), a signal (FIG. 8b). )

  allowing the reading of the coded word formed by the exponent.

  At the same time, on this signal, the coded word of the exponent is recorded in the register 51 (FIG. 2) of the code of the exponent. While in block 50, all the N code words of the spectral components of the given reading extraction are recorded, the control input 8 of the code converter 6 is driven from the output of the shaper 9 (FIG. 1), by a signal (FIG. 8b) allowing the recording, from the output of the detector 49 (FIG. 2), in the register 51 of the coded word of the last (twenty fourth) exponent of the sample of readings examined. After registering in the register 51 of the last (twenty fourth) codeword of the exponent, the control input 8 of the code converter 6 sees a positive pulse appear (FIG. 8c) which, by attacking the respective input of the register 51 (FIG. 2), gives the instruction to record the first code word of

2 2639779

  the exponent from the output of the register 51) in the encoder 52 of the floating-point code. Since the output 17 of the code converter 6, this codeword attack

  the respective input of the multiplexer 16 (Figure 1).

  At the same time, the output of the block 50 (FIG. 2) provides the coded word of the first spectral component of the examined sample of readings that drives the input of the encoder 52. The coded word is shifted therefrom. a number of bits imposed by the value of the coded word of the exponent coming from the output of the register 51 to the input of the encoder 52. Thus are formed coded mantissa words of the spectral components coming from the output 18 of the converter 6 on the input of the multiplexer 16 (Figure 1). The coding of the spectral components coming from the output of the buffer memory block 50 (FIG. 2) for the same value of the exponent continues until the moment when the other input of the encoder 52 is attacked by a new word

  coded the order provided by the output of the register 51.

  In this case, the coded words of the spectral components are shifted by the number of bits corresponding to the second coded word of the exponent arriving at the input of the coder 52 from the output of the register 51. This process continues until the moment when the twenty four coded words of the exponents of the examined sample are read from the register 51. For the samples of N subsequent readings, the coding process proceeds in the same way. The multiplexer 16 (FIG. 1) realizes the redistribution over time of the coded words of the exponents and the mantissas so that the sequence of pulses at its output becomes regular. The repetition frequency of the pulses at the output of the multiplexer 16 is defined by the following expression: Fout = (24Kp + nKM) Fd / N, (2) where K is the number of bits of the exponent, Km is the number of bits of the mantissa, Km is the number of bits of the mantissa, N is the number of readings in a sample. The operation of the analog-digital converter 2, the buffer memory block 3, the spectral conversion block 4, the code converter 6, the control pulse shaper 9, the memory block 12 containing the numbers of the spectral components, and the multiplexer 16, is synchronized by the synchronization pulse generator 21. The output 22 of the generator 21 releases the pulses at a frequency Fd, the output 23, pulses at a frequency Fd / N, the output 24 provides the pulses at a frequency 16Fd and the output 25, the pulses at a frequency Fout 'The pulse shaper 9

  (Figure 3) works as follows.

  The counting inputs of the counters 53, 55, 63 and 65 serving as synchronization inputs to the shaper 9 are driven from the output 24 (FIG. 1) of the synchronization pulse generator 21 by a sequence of pulses at a frequency equal to 16Fd. This pulse sequence determines the repetition frequency of the bits of the coded words of the spectral components. The reference inputs of the counters 53 and 55 (FIG. 3) are driven by a sequence of pulses at a frequency equal to Fd / N coming to the output 23 (FIG. 1) of the synchronization pulse generator 21. This sequence of FIG. The pulses define the beginning of the extraction of N readings of the sound broadcasting signal, which makes it possible to calculate the spectrum and, respectively, the beginning of the spectral component sequence of this sample of readings. The pulses coming from the output 23 of the synchronization pulse generator 21 switch on the counters 53 (FIG. 3) and 55. From the output of the counter 53 comes the code of the number of the spectral component which attacks a group of The inputs of the second group of inputs of the comparator 54 are driven from the output of the memory block 12 (FIG. 1) containing the spectral component numbers of the critical bands of the hearing by the number code. of the last spectral component in the given frequency group. When the codes on the first and second input groups of the comparator 54 (Fig. 3) coincide, the output thereof provides a signal which turns on the counter 63 and sets the flip-flop 64 to the "1" state. logic. In addition, the signal supplied by the output of the comparator 54 drives the input 13 (FIG. 1) of the memory block 12 and ensures the reading, from its respective output, of the code of the number of the last

  spectral component of the next frequency group.

  The counter 63 (FIG. 3) counts a predetermined number of pulses driving its counting input, and produces a signal which sets the flip-flop 64, which is at "1", to the "0" state, and the flip-flop 66, in state "1". In addition, the output signal of the counter 63 starts the counter 65, which, like the counter 63, counts the given number of pulses and produces a signal which switches the flip-flop 66 from the logic "1" state to the logical "0" state. Thus, the outputs of flip-flops 64 and 66 release the pulse sequences (FIG. 8b, c) which control the operation of the

code converter 6 (Figure 1).

  The counter 55 (FIG. 3), after having counted the predetermined number of pulses, produces the start signal of the counter 56, whose input receives, from the output 25 (FIG. synchronization pulses 21, a sequence of pulses at a frequency equal to Fout. On the output of the counter 56 (FIG. 3), the code is taken

  the number of the next impulse attacking its input.

  This code is compared in the comparator 57 with the code of the number of the pulse corresponding to the last bit of the code of the exponent of the given frequency group which drives the second input of the comparator 57 from the output of the memory block 12 ( figure 1). At the coincidence of these codes, the output of the comparator 57 (FIG. 3) releases a signal which turns on the

  counter 58 and switches the flip-flop 60 to the "1" logic state.

  In addition, the signal coming from the output of the comparator 57 drives the input 14 (FIG. 1) of the memory block 12 and reads, from its respective output, the code of the number of the pulse corresponding to the last bit of the code of the exponent of the next frequency group. The counter 58 (FIG. 3) counts the number of pulses equal to the number Kp of bits in the coded word of the exponent and produces a signal which switches the flip-flop from the logic "1" state to the "0" state. "logical. The output of the flip-flop 60 provides pulses (FIG. 8d) which attack the control input 19 (FIG. 1) of the multiplexer 16 and the input of the inverter 62 (FIG. 3), on the output of which the pulses are taken. (Figure 8e) attacking the entrance

  20 (FIG. 1) of the multiplexer 16.

  The memory block 12 (FIG. 4) containing numbers of the spectral components of the bands

  Hearing critics work as follows.

  The counting inputs of the counters 67 and 69 are driven by the pulses provided by the respective outputs of the shaper 9 (FIG. 3), and the reference inputs by the pulses coming from the output 23 (FIG. 4) of the pulse generator of FIG. synchronization 21 and the corresponding output of the shaper 9 (Figure 3). These pulses switch on the counters 67 and 69 (FIG. 4). On the outputs of the counter 67, are taken the codes of the addresses of the codes of the numbers of the last spectral components of the groups of frequencies which are recorded in the fixed memory 68 of the codes

36 2639779

  of these numbers are read to attack the input 10 (Figure 3) of the shaper 9. On the outputs of the counter 69 (Figure 4) are taken from the codes of the addresses of the codes of the numbers of the pulses corresponding to the last bit bits of the codes of the exhibitors of frequency groups. Since the output of the fixed memory 70, the codes of these numbers

  arrive at the inlet 11 (FIG. 3) of the shaper 9.

  The decoder of the device works from the

following way.

  The bit sequence of the floating point block code of the spectral components of the sound broadcasting signal supplied by the output of the multiplexer 16 (FIG. 1) drives the input of the demultiplexer 26 which carries out the separation of the input sequence in sequence. bits of the coded words of exponent and in sequence of bits of the coded words of the nantisses. The demultiplexer 26 isolates from the bit input sequence, the clock frequency Fout from their repetition, and the pulse sequence at this repetition frequency passes to the output 45 of the demultiplexer 26. In addition, the demultiplexer 26 isolates of the received sequence, the clock cycle signal defining the beginning of the spectral component block corresponding to the next transmitted sample of N readings of the sound broadcast signal. The pulses of the clock cycle signal at the recurrent frequency Fd / N pass to the output 46 of the

demultiplexer 26.

  The code converter 29 converts the words of the floating point block code into words

  encoded 16-bit linear code with fixed point.

  Then, the bits of the exponent code provided by the output 27 of the demultiplexer 26 at the clock frequency Fout supplied by the output 45 of the demultiplexer 26 are recorded in the register 76 (FIG. 6) of the code of the exponent d 'o, on a signal of

37 2639779

  control (Figure f8) from the output 37 (Figure 1) of the shaper 34, they are sent in parallel code on the first group of inputs of the comparator 77 (Figure 6). The inputs of the second group of inputs of the comparator 77 are driven by the signals coming from the outputs of the counter 80 whose count input receives the pulses at a clock frequency of 16 Fout from the output 47 (FIG. 1) of the generator synchronization pulses 44. The output of the comparator 77 (FIG. 6) provides a signal which controls the operation of the register 79 and at the same time

  time sets the counter 80 to the initial state.

  The mantissa code bits, provided by the output 28 (FIG. 1) of the demultiplexer 26, at the clock frequency Fout, attack the input of the KM bit register 81 (FIG. 6) of the mantissa code of o, on a control signal (FIG. 8g) coming from the output 36 (FIG. 1) of the shaper 34, the sign bit is rewritten in the register 16 (FIG. 6) in place of the sign bit of the decimal code fixed, and the other (KM - 1) bits of the mantissa, in parallel code, are rewritten at the locations (KM - 1) of the lower bits of the register 79 at 15 bits. In this register 79, they are successively shifted at the clock frequency 16 Fout coming from the output 47 (FIG. 1) of the synchronization pulse generator 44. From the output 35 of the shaper 34 arrives at the input of FIG. control of the register 79 (FIG. 6), a signal (FIG. 8h) defining the beginning of the mantissa bit offsets. This signal also turns on counter 80 (FIG. 6), which counts the number of offsets made. When the necessary number of offsets defined by the code of the exponent is realized, the second input of the comparator 77 is attacked, since the output of the counter 80, by a combination of code coinciding with the code of the exponent registered in the register

38 2639779

  76, and the output of the comparator 77 releases a read signal of the contents of the register 79 and its rewrite on the fifteen-bit locations of the register 84. At the same time, this signal sets the counter 80 to the initial 0 state. Thus, in the register 84, a word of the 16-bit fixed-point code is formed, which, on a control signal (FIG. 8i) taken from the output 38 (FIG. 1) of the shaper 34, is recorded in the block of buffer storage 30, which delays the sequence of incoming codewords by two cycles at the frequency Fd / N,

in other words, 2 N codewords.

  The buffer block 30 is intended to adapt the arrival speed of the coded words of the spectral components coming from the output of the converter 29 to the speed of their processing in the inverse spectral conversion block 31 where the restitution of the sample of N readings according to its N spectral components. On the output of the inverse spectral conversion block 31, are taken in parallel code the 16-bit coded words of readings of the sound broadcasting signal driving the digital-to-analog converter 32, which regenerates the quantized readings of the broadcasting signal.

  sound. On the output of the digital converter-

  analog 32, is connected the low-pass filter 33 which smooths the quantized readings and in this way renders the analog sound broadcast start signal with a frequency band not

not exceeding F = 15 kHz.

  Thus, at the output of the encoder of the device, the initial signal is represented by a digital stream transmitted with a speed defined by the expression (1), from which the decoder restores the signal

initial analogue.

  During the experimental study of the device for coding and decoding sound broadcasting signals, the length of a sample was chosen.

39 2639779

  N = 1024, the number of bits of the exponent Kp = 4, the number of mantissa bits KM = 5 and the sampling frequency in the time Fd = 32 kHz. In this case, the speed of the digital stream at the output of the coding device was V = 163 kbit / s, that is to say twice as small as in the device constituting the closest prior art. The sound quality tests demonstrated that the sound quality of broadcast signals encoded and decoded using the claimed device is no worse than the quality of the original digital signal whose readings were coded by a code

linear to 16 bits.

  The encoder for broadcast stereo signals includes, cascaded, a main low pass filter 88 (Fig. 9) and a main analog-to-digital converter 89 for the left stereo channel and, cascading, a filter

  auxiliary low pass 90 and an analog converter

  Auxiliary Digital 91 for the Right Stereo Channel.

  The inputs of the low-pass filters 88 and 90 serve as input to the encoder. The outputs of the analog-to-digital converter 89 are connected, bit by bit, to inputs 92 of an arithmetic unit 93 whose inputs 94 are connected, bit by bit, to the outputs of the analog-to-digital converter 91. The outputs of FIG. a group of outputs 95 of the arithmetic unit 93 are connected, bit by bit, to the inputs of a first group of information inputs of a buffer memory block 96 and to the inputs of a filter block A group of outputs 98 of the arithmetic block 93 are connected, bit by bit, to the respective inputs of the digital filter block 97 and to the inputs of a signal conversion block 99 carrying the information on the stereo signal. broadcasting. Groups of outputs 1001 ... 100m, ml ...-11002m of block 97 of digital filters are

2639779

  connected, bit by bit, to the respective inputs of the signal conversion block 99 whose outputs of a group of outputs 101 are connected to the second group of information inputs of the buffer memory block 96. The outputs of the groups outputs 1021 ... 102m from block 99 are connected to the information inputs of the auxiliary code converters 1031 ... 103m, each having two groups of outputs. The outputs of the first groups of outputs of the converters 1031 ... 103m are connected to inputs 1041 ... 104m of a multiplexer 105 and the outputs of the second groups of the outputs of the converters 1031 ... 103m are connected to inputs

1061 ... 106m of the multiplexer 105.

  In addition, the broadcast stereophonic signal encoder includes a spectral conversion block 107 whose inputs 108 are bit-wise connected to the outputs of the buffer memory block 96; the outputs of the spectral conversion block 107 are connected, bit by bit, to the information inputs of a main code converter 109. Control inputs 110 and 111 of the code converter 109 are connected to the respective inputs of a control pulse shaper 112. Outputs 113 and 114 of the code converter 109 are connected to the respective inputs of the

multiplexer 105.

  The encoder also comprises a memory block 115 containing the spectral component numbers of the critical bands of the hearing whose inputs 116, 117, 118 and outputs 119, 120 are connected, bit by bit, to the respective outputs and inputs. the control pulse shaper 112, the outputs 121, 122 of which are connected to the respective inputs of the multiplexer 105. In addition, the sound stereo signal encoder includes an OEI qua pulse generator inexaIdT $ Inu np 9Et ' 5EI sasT-os its' uodUea uoTqUsTIoUaU apoolq a q9 CEC es2aAuT ua sqdGds Sc UOTSlaAUOD ap dd a 'Zu1 uodue $ uoTgsT2loaue ap daqq a' IEI [edTouTzd apoo ap InassT-zaAUoD a 'apeosse a tue' a ndUpla qass apaque to some OCI anaxaldI $ Inuap a: a $ qodooD a2ouos uoTsng; poTp22 ap sanbTuoudoa2aazs xneuTs anod 2nGpooap aq Oc 501T anexaldTqlnui np oa 96 UOdU! Pq UoTUSTaolMaU apoolq rp EOUIo "IEOI 8poD @p slanSsTqa ^ AUOD sap '66 xneueTs apuoTslaauoD ap oolq np seAT?, sCdse sapaqua sal ans aaqoU22q qsa CEI uoTqUSsTuo0qDuZs ap suoTslndUTp anaqlauab5 np 6ZI al40os 9E 9UI 'G01 IznaxaldTqTnu np -a 96 uodue-4 uoT4esT.ZoZal ap Oolq np' úOi '' I [OT GpoD ap slnasssq2aAuoo sap '66 xnleu56s ap UOTS2aAUOO ap oolq np 'L6 serzbT rlnu saalT; ap zolq np 'ú6 9nbT * 9sTqT2V aqTun, to aP '16 '68 sSnblanussnbTZoiu slnassTqaAuoD sap oz saTqCadsasl UoT-ESTUoqLOUS ap s9a2'ua sal ans aaqouiZq? sa úZI uoTqsuolgouKis ap suoTslndmZ, p anaqpa2, uefb np 8ZI 9Tq2os au ,. ## EQU1 ## where: ## EQU1 ## uoo np saTqDoadsai uoTzus-TuoiqOuXs ap saaz9ua sal ans aptUouvaq qsa 51 Zl Uo7% esTuo02-DU.Xs ap suoTsindT, p ana, ez-eueB np LEI aT:;. os auh 'EII puleaoO ap suoTsLndaZ, p anaqgomuoo np aAqDaCdsa2 Uo7TesTuo0oDuKs ap aalZuail yyqouelq? its EZI UO7% USTUo0lqDUÀS ap suoTslndaT, p anaevapuab np 9ZI aeT2os au, 1 '0T InaxasdTqln np ea GIT a2To9au 01 apoolq np' apUIZOD ap suoTslnd ^ ZT, p ZIl inaeiojuco np 'LAW aliez-4ads uoTs. aAuoO ap np zoIq '96 uodu $ uoTqVsTzola oolq ap np seA! oadsa9 uoTq2sTuoaqouAs ap saalqUe sal years $ aaqDuelq 4SA CZE uoT4esTuolqDuAs suoTsIndZT ap p np anaqV2auga5 GZL aTqIos to * 501 5 601 apoo 2naXaldTqlni np q ap InassT $ 4aAUOo np 'LAW alv2qDads uo! sleAuOD ap DoTq np '96 uodumu uo! $ us! 2o0, at the ap oolq np sa ^ Igsadsa2 uo $ esuolqOuKs ap saaaua xne aPTIal qsa tZI aeTaos auNoT UoTqSsTooDqOuKs

6Z 6ú9E 2 9

42 2639779

  connected to the respective inputs of the converter of

* code 131.

  The decoder also includes m auxiliary code converters 1371 .. .137m each of which has two information inputs. On the first information inputs of the code converters 1371 ... 137m are connected outputs 1381 ... 138m of the demultiplexer 130, and on the second inputs of the code converters 1371 ... 137m are connected outputs 1391 .. 13m of the demultiplexer 130. The outputs of the converters 1371 ... 137m are connected, bit by bit, to information inputs 1401 ... 140m of a reproduction block of the stereophonic signal 141. In addition, the decoder comprises a digital filter block 142 whose information inputs are connected, bit by bit, to a group of outputs 143 of the buffer storage block 134, a group of outputs 144 of which are connected to the respective inputs of the stereophonic signal reproduction block 141 at inputs 1451 ... 145m of which are connected the outputs of the digital filter block 142. An output 146 of the stereophonic signal reproduction block 141 is connected to, cascaded, a converter

  main analog-digital 147 and a pass filter

  main downstream 148, and an output 149 is connected to, cascaded, an auxiliary digital-to-analog converter 150 and an auxiliary low-pass filter 151, the outputs of the filters 148 and 151 serving as outputs

to the decoder.

  The decoder also comprises a control pulse shaper 152, a memory block 153 containing the spectral component numbers of the critical bands of the hearing and a synchronization pulse generator 154. Outputs 155, 156, 157, 158 shaper 152 are connected to the respective inputs of the code converter 131, and the outputs 155 and 156 are, in addition,

43 2639779

  connected to the inputs of the demultiplexer 130. Outputs 159 and 160 of the shaper 152 are connected to the respective inputs of the memory block 153, the outputs 161 and 162 of which are connected, bit by bit, to the respective information inputs of the

shaper 152.

  An output 163 of the demultiplexer 130 is connected to the respective inputs of the generator 154, the buffer memory block 134 and the code converters 1371 ... 137m. An output 164 of the demultiplexer 130 is connected to the respective inputs of the converter 152, the converter code 131 and the generator 154 whose output 165 is

  connected to the respective input of the shaper 152.

  An output 166 of the manager 154 is connected to the respective inputs of the buffer storage blocks 132, 134 and the inverse spectral conversion block 133. An output 167 of the generator 154 is connected to the respective inputs of the buffer storage blocks 132 and 134, the inverse spectral conversion block 133, the memory block 153, the shaper 152 and the code converter 131. An output 168 of the generator 154 is connected to the respective inputs of the buffer memory block 134, code converters 1371. ..137mr, the digital filter block 142, the stereophonic signal reproduction block 141 and the

  digital-to-analog converters 147, 150.

  The low-pass filters 88, 90, 148, 151, the digital analog converters 89, 91, the converters of the codes 1031 ... 103m, 109, 131, 1371 ... 137m, the spectral conversion block 107, the conformers of control pulses 112, 152, the memory blocks 115, 153 containing the spectral component numbers of the critical bands of the hearing, the synchronization pulse generators 123, 154, the multiplexer 105, the demultiplexer 130, the block inverse spectral conversion 133 and the

44- 2639779

  digital-to-analog converters 147, 150 are made in the same way as the respective blocks of the signal coding and decoding device

  monophonic sound broadcasting.

  The block diagram of the arithmetic unit 93 is shown in FIG. 10. It includes an adder 169 and a subtractor 170. The inputs 92 and 94 of the arithmetic unit 93 are connected to the

  inputs of the adder 169 and the subtractor 170.

  The output of the adder 169 serves as an output 95 to the arithmetic unit 93, and the output of the subtractor serves as the output 98 of the unit 93. The adder 169 and the subtracter 170 can be realized using known arrangements ( "Semiconductor Mounts Technique", Memento, U. Titse, K. Chenk, 1982,

pp.334, 335).

  The block diagram of the digital filter block 97 is shown in FIG. 11. It has two groups of digital filters 1711 ... 171m and 171m + 1 ... 1712n. The digital filter inputs 1711 ... 171m and 171+ 1 ...- 1712m are connected together and used as inputs to block 97. The synchronization inputs of digital filters 1711 ... 1712m are connected to the output 128 (FIG. 9) of the generator 123 and their outputs serve as outputs 1001 ... 100m, 100m + 1 ... 1002m (FIG. 11). The digital filters 1711 ... 1712m can be made using known assemblies ("Solid State Milling Technique", Memento, U. Titse, K. Chenk, 1982,

P.429).

  The block diagram of the signal conversion block 99 carrying the information on the sound broadcasting stereo signal is shown in FIG. 12. It comprises m channels, each of which contains, cascaded, an adder 172, a multiplier 173, an adder 174, a register and a switch 176 whose output 577 is

2639779

  connected to the corresponding input of the adder 174. Each of the m channels also comprises a register 178 whose information input is connected to an output 179 of the switch 176, an adder 180 of which one of the inputs is connected to the output 179 of the switch 176 and a divider 181 whose inputs are respectively connected to the outputs of the register 178 and the adder 180. In addition, each channel comprises, cascaded, a subtractor 182, a multiplier 183, an adder 184, a register and a switch 186 whose output is connected to the respective inputs of the adders 180 and 184. The inputs of the adder 172 and the subtractor 182 of the first channel are respectively connected to the outputs 1001 ... 10m + ( 9) of the digital filter block 97. The inputs of the adders 172 (FIG. 12) and the subtractors 182 of the other ML channels are respectively connected to the outputs 1002 and 1COm_2, 1003 and 10100-3, .... 100m and 1002m (Fig. 9) of block 97. The outputs of dividers 181 (Fig. 12) serve as outputs to the channels and outputs 1021 ... 102m respectively of block 99. Block 99 also includes, cascaded, an adder 187, whose inputs are connected to the respective outputs 00m + .l-. 1002m (Figure 9) of block 97, and a subtractor 188 (Figure 12), whose output serves as an output 101 to block 99, and further comprises a register 189, the input is one of the inputs of block 99, connected to the output 98 (FIG. 9) of the arithmetic unit 93, and the output of the register 189 (FIG. 12) is connected to another input of the subtractor 188. The synchronization inputs of the adders 172, 174, 184 , 187, subtractors 182, 188, multipliers 173, 183, registers, 185, 189, are connected to the output 128 (FIG.

  9) of the synchronization pulse generator 123.

462639779

  The synchronization inputs of the switches 176, 186 (FIG. 12), the register 178, the adder 180 and the divider 181 are connected to the output 129

(FIG. 9) of the generator 123.

  The adders 172, 174, 180, 184, 187 (FIG. 12), the subtractors 182 and 188, the multipliers 173, 183 may be implemented using known arrangements ("Semiconductor Mounts Technique", Memento, U. Titus, K. Chenk, 1982,

pp.335, 340).

  The divider 181 can be made with a known arrangement (P. Rabiner, P. Gould, "Theory and application of digital signal processing", Mir,

Moscow, 1978, p.584).

  The registers 175, 185, 178, 189 and the switches 176, 186 can be made using microcircuits of the SN 7400 series,

available in the industry.

  The block diagram of buffer memory block 96 is shown in FIG. 13. It has switches 190, 191. The input of switch 190 is one of the inputs of block 96 and is connected to output 95 (FIG. 9). of the arithmetic unit 93, and the input of the switch 91 (FIG. 13) is connected to the output 101 (FIG. 9) of the conversion block 99; Block 96 (FIG. 13) also comprises read-write memories 192, 193, 194, 195 and a switch 196. Outputs 197, 198 of switch 190 are connected, bit by bit, to the information inputs of FIGS. read-write memories 192, 193, and outputs 199, 200 of the switch 191, on the information inputs of the write-read memories 194 and 195. The control inputs of the switches 190, 191 are connected to the output 125 (FIG. 9) of the synchronization pulse generator 123.

  synchronization inputs of the writing memories-

  192, 193, 194, 195 (FIG. 13) are connected to the outputs 124, 128 (FIG. 9) of the synchronization pulse generator 123, and the outputs of the write-read memories 192, 193, 194, 195 (FIG. 13) are respectively connected to inputs of the switch 196, the control inputs of which are connected to the outputs 125, 129 (FIG. 9) of the synchronization pulse generator 123, and the output of the switch 196 (FIG. 13) serves as an output. to the buffer memory block 96 and is connected to the input 108

  (FIG. 9) of the spectral conversion block 107.

  The switches 190, 191, 196 (FIG. 13) can be realized using commercially available SN 7400 series microcircuits, and the read / write memories 192, 193, 194, 195,

  using microcircuits of the type I ^^ 2141-5.

  The block diagram of the buffer memory block 134 is shown in FIG. 14. It comprises switches 210, 202, 203 and write-read memories 204, 205, 206, 207. The control inputs of the switch 201 are, respectively, connected to the output 167 (Figure 9) of the synchronization pulse generator 154 and the output 163 of the demultiplexer 130, while the information input of the switch 201 (Figure 14) serves as input to the block 134 Outputs 208, 209, 210, 211 of the switch 201 are connected, bit by bit, to the information inputs of the write-read memories 204, 205, 206, 207 whose synchronization inputs are connected to the outputs 166 and 168 (FIG. 9) of the synchronization pulse generator 154. The outputs of the write-read memories 204, 205 (FIG. 14) are connected to the inputs of the

  switch 202, and the outputs of the write-memories

  reading 206, 207 on the inputs of the switch 203.

  The control inputs of the switches 202, 203 are connected to the output 163 (FIG. 9) of the demultiplexer 130. The outputs of the switches 202,

48 2639779

  203 (FIG. 14) serve respectively as outputs 143 and 144 in block 134 and are connected to the inputs of the digital filter block 142 (FIG. 9) and of the stereophonic signal reproduction block 141, respectively. Switches 201, 202, 203 (FIG. 14) can be realized using commercially available SN 7400 series microcircuits, and write-read memories 204, 205, 206, 207,

  using microcircuits of the type M 2141-5.

  The structural diagram of the stereophonic signal reproduction block 141 is shown in FIG. 15. It comprises, cascaded, an adder 212 and a register 213 and, cascaded, a subtractor 214 and a register 215. The respective inputs of FIG. the adder 212 and the subtractor 214 are joined and serve as input 1451 to the block 141; in addition, they are connected to the output 144 (FIG. 9) of the buffer memory block 134. The output of the register 213 (FIG. 15) is connected to an input 216 of an adder 217, and the output of the register 215 is connected. at an input 218 of an adder 219. In addition to this, the block 141 also comprises m identical channels containing multipliers 220 ....... 220m, registers 2211 ... 221m

  and 2221 ... 222m and subtractors 2231 ... 223m.

  Some inputs of all the multipliers 2201 ... 220m serve as information inputs 1401 ... 140m at block 141 and are connected to the outputs of the code converters 1371 ... 137m (FIG. 9). Other inputs of the multipliers 2201 ... 220m (FIG. 15) are combined with inputs of the registers 2221 ... 222m and serve as inputs 1451 ... 145m + 1 connected to the

  outputs of the digital filter block 142 (FIG. 9).

  The outputs of the multipliers 2201 ... 220m (FIG. 15) are connected, bit by bit, to the information inputs of the registers 2211 ... 221m and to the inputs

49 2639779

  respective of the subtractors 2231 ... 223m on other inputs of which are connected the outputs of the registers 2221 ... 222m. The outputs of the registers 2211 ... 221m constitute outputs of the channels and are connected to inputs 2241 ... 224m of the accumulator 217, and the outputs of the subtractors 2231 ... 223m constitute other channel outputs. are connected to inputs 2251 ... 225m of the adder 219. The outputs of the adders 217 and 219 respectively serve as outputs 146 and 149 at the block 141 and are connected to the inputs of the digital-to-analog converters 147 and 150. (Figure 9), respectively. On the synchronization inputs of the additonnonneurs 212, 217, 219 (FIG. 15), subtractors 214, 2231 ... 223m, registers 213, 215, 2211 ... 221m, 2221 ... 222m, are connected to the output 168 (FIG. 9) of the pulse generator of

synchronization 154.

  The adders 212, 217, 219 and the multipliers 2201 .... 2202 (FIG. 15) can be realized using known arrangements ("Solid-State Mounting Technique", Memento, U. Titse, K. Chenk, 1982 , pp.334-335-340). The registers 213, 215, 2211 ... 221m, 2221 ... 222m can be made based on microcircuits SN 7400 series, available

in industry.

  FIG. 16 shows the amplitude-frequency characteristics of the digital filters 1711 ... 1712m (FIG. 11) forming part of the digital filter block 97, where:

  16a is the amplitude characteristic-

  frequency of the filters 1711 and 171 + 1 (FIG. 11), fo and fl (FIG. 16a) being the limit frequencies of the passband of the filters 1711 and 171m + 11 (FIG. 11);

  16b is the amplitude characteristic-

  frequency of the filters 1712 and 171m + 2 (FIG. 11), fl and

-2639779

  f2 (FIG. 16b) being the limit frequencies of the passband of the filters 1712 and 171m + 2 (FIG. 11);

  16c is the amplitude characteristic

  filter frequency 171m and 1712m (Figure 11), fm-

  and fm (Figure 16c) being the limiting frequencies of the

  bandwidth filters 171met 1712m.

  The claimed device for coding and decoding stereophonic broadcast signals

works as follows.

  In the encoder, the analog signals of the left and right stereophonic channels drive the inputs of the low-pass filters 88, 90 (FIG. 9), and then the analog-digital converters 89, 91 put in series with the first ones in the same way only in blocks 1 and 2 (Figure 1). The coded words of the readings of the left and right stereophonic channels formed in the analog-to-digital converters 89, 91 (FIG. 9) arrive in the arithmetic unit 93

  o are calculated their half-sum X + and half

  difference X_. The coded words corresponding to half

  sum X + left and right stereophonic channels released from the output 95 go to the corresponding input

  of the buffer memory device 96.

  To separate and encode information

  stereophonic, the coded words corresponding to half

  X + sum and the half-difference X_ left and right stereo channels are sent to the inputs of the block of digital filters 97 performing their band-pass filtering. The digital filter block 97 has two identical multiple filters, each with m filters 1711 ... 171m and 171m + 1 ... 1712m (FIG. 11), respectively, for the signals corresponding to the half-sum X + and the half-difference X_. The amplitude-frequency characteristics of the filters 1711 ... 1712m are shown in FIG. 16. Thus, the outputs 1001 ... loo100m (FIG. 11) of the digital filter block 97 release the readings of m signals.

51 2639779

  filtered X + (1), X + (2), ... X + (m) of the half-sum X +, and the outputs 100m + 1.

  , 1002m, the readings of m filtered signals X_ (1), X_ (2), ... X_ (m) of the half-difference X_ of the left and right stereophonic channels. These read sequences of the filtered signals X + (1) ... X + (m) and X_ (1) ... X_ (m) arrive in the conversion block 99 (FIG. 9). The input of the block 99 also receives a signal corresponding to the half-difference X_ of the output 98..DTD: of the arithmetic unit 93.

  In the conversion block 99, for each

  pair of filtered signals X + (i), X_ (i) (i = 1, 2, ...

m), is calculated the ratio:

('? () () (3)

  e. (i) is the derivation of these filtered rings y ands () R of the cgam st and o-ontic pathways, respectively, alces cue: i (i) = X (i) X (i)

_ 1- (5)

  The energy is calculated over a time interval T = N / FD corresponding to N readings of the start signal so that: (i) = r 0i nj. 2 (6)

ET = -D

  v i - 2 R = n -R (Since the energy is calculated over the time interval 4 T of N readings, the ratios Pi (i = 1,

52 2639779

  2, ... m) are formed only once in this time interval. In addition, in the conversion block 99, the readings X_ (O0) of the differential signal filtered in the frequency band from 0 to 10 Hz are formed. For this purpose, the operations are carried out according to the formula: x (0) = _ x (i) Cs)

- - ij = 1 -

  The conversion block 99 (FIG. 12) comprises identical processing steps for the filtered signals XT (i), X_ (i). Let's examine the function of one of these flights. On the inputs of the adder 172 and the subtractor 182, are sent from the outputs 1001 and 10m + 1 (FIG. 11) of the digital filter block 97, the code words of the reads of the filtered signals X + (1), X_ (1). ). At the outputs of the adder 172 (FIG. 12) and the subtracter 182, coded words are formed corresponding to the first filtered signals XL (1) and XR (1) of the left and right channels which are sent to the multipliers 173 and 183. At the outputs of the multipliers 173 and 183, coded words are formed, corresponding to the squares of the readings of the filtered signals XL (1) 2, i XR (1)]. The values EL () and ER (1) of energy of the Filter signals are calculated using adders 174 and 184, registers 175 and 185, and switches 176 and 186. At the beginning of the addition cycle, on a synchronization signal driving the input of the conversion block 99 from the output 129 (FIG. 9) of the generator 123, the switch 176 (FIG. 12) connects the outputs of the register 175 to the respective inputs of the adder 174. The inputs of the second group of inputs of the adder 174 are attacked by the coded words corresponding to the squares of the readings of the filtered signal [XL (1)] 2 of the left stereo channel. The result of the addition is recorded in the register 175. Thus, at the end of the

53 2639779

  addition cycle, the register 175 accumulates the value of the sum of the squares of the readings of the filtered signal of the left channel, according to formula (6), equal to the energy EL (i) of the filtered signal. The circuit for calculating the energy of the filtered signal of the right channel which comprises the adder 184, the register 185, and the

  switch 186, works the same way.

  At the end of the addition cycle, on the synchronization signal driving the input of block 99 from output 129 (FIG. 9) of generators 123, switch 176 (FIG. 12) connects the outputs of register 175 to the inputs of FIG. register 178, and the switch 186 connects the outputs of the register 185 to the inputs of the addreur 180. The register 178 carries the delay of the codeword corresponding to the energy value of the filtered signal of the left stereo channel for a time equal to the execution time of the addition operation by the adder 180. At the output of the adder 180 a coded word is formed, corresponding to the value of the sum EL (1) + ER (1) energies of the filtered signals of the left and right stereophonic channels, sent to the respective inputs of the divider 181. Further inputs of the divider 181 are driven from the output of the register 178 by a coded turn corresponding to the value EL (1) of the signal energy of the stereo channel left reophonique. At the output of the divider 181, a coded word is formed corresponding to the value of the ratio P1 calculated using the formula (3). The calculation channels P2 ... Pr, work in the same way. The operation of the adders 172, 174, 184, the multipliers 173, 183, the registers 175, 185, of the subtracter 182 is synchronized by a clock frequency at which the readings of the sound broadcasting signal attacking the input of the conversion block 99 (FIG. 9) from the output 128 of the generator 123.

54 2639779

  operation of the register 178, the adder 180 and the divider 181 (FIG. 12) is synchronized by a deblocking pulse defining the duration of the addition cycle when calculating the energy of the filtered signals and going to the input of the conversion block 99

  (Figure 9) from the output 129 of the generator 123.

  The calculation of the differential signal X_ (O0) filtered in the frequency band 0 to fo Hz is done by the adder 187, the subtractor 188 and the register 189 (Figure 12). Then, the inputs 100m + 1 ... 1002m of the block 99, that is to say the inputs of the adder 187, are attacked by the filtered signals X_ (1), X_ (2), ..., X_ (m). From the output of the adder 187, the coded words corresponding to the sums of the filtered signals are sent to one group of inputs of the subtractor 188. The other group of inputs of the subtractor 188 is driven by the differential signal X_ delayed in the register 189, for the operating time of the adder 187. Thus, at the output of the subtractor 188, are formed the coded words of the readings of the signal X_ (O) according to the formula (8). From the outputs 1021 ... 102m of the conversion block 99, the coded word sequences corresponding to the ratios Pl ... Pm succeeding one another at the frequency Fd / N attack the inputs of the code converters 1031 ... 103m (FIG. 9 ), and from the output 101, the coded word sequences of the readings of the signal X_ (0), which follow each other at the frequency Fd, attack the corresponding input of the buffer memory block

96 (Figure 9).

  The buffer storage block 96 carries out the delay of the coded word sequences of the readings of the signal X + of the half-sum of the left and right stereo channels and the filtered half-difference signal X_ (O) attacking its inputs to adapt them to the flow velocity arriving at the entrance to the block of

5 2639779

  spectral conversion 107. Then, the signals X + and X_ (0) attack the inputs of the switches 190, 191 (FIG. 13) controlled by a deblocking pulse of a duration equal to the addition cycle realized in the conversion block 99 (FIG. 9) so that the time interval during which the spectral analysis is made is equal to the time interval during which the average of the squares of the readings of the

  signals for calculating the energies EL (i) and ER (i).

  Thus, during the first N clock periods, the switches 190, 191 (FIG. 13) ensure the recording of the coded words of the readings of the signals X + and X_ (i), respectively, in the read-write memories 191, 194, and the N periods

  clock in the writing memories-

  reading 193 and 195, the information then being read in the memories 192, 194. The recording of the information in the memories 192, 193, 194, 195 is done at the clock frequency Fd, and the reading, at the frequency 2Fd. The switch 196 in turn connects the outputs of the write-read memories 192, 193, 194, 195 to the output of the buffer memory block 96 so that at the output of the block 96 a sequence of code words is formed. readings of the signals X + and X_ (O0) which follow each other at the frequency 2Fd, the group of N coded words of the readings of the signal X + forming first, and then the group of N coded words of the

  X_ (O) signal readings, and so on.

  The sequence of coded words of the readings of the signals X + and X_ (0) arrives in the spectral conversion block 107 (FIG. 9) and then in the code converter 109. The code converter 109 is controlled by the signals produced by the control pulse shaper 112 and the memory block 115 containing the numbers of the

  spectral components of the critical bands of hearing.

2639779

  The operation of the blocks 112, 115 is of the same kind

  coding of monophonic signals.

  In the code converters 1031 ..., 103m, the coded words corresponding to the ratios P1 ... Pm are recoded to a floating-point code in the same way as in FIG.

known device.

  The coded words of the exponents and the mantissas provided by the outputs of the code converters 1031 ... 103m are sent to the inputs 1041 ... 104m and 1061 ... 106m of the multiplexer 105 which unites them in a single digital stream transmitted to the clock frequency Fs defined using the expression: Z- =: e + F '+ p

X (9)

  or if, -, is the repetition rate of the code pulses of the signal X_; -2 is the repetition frequency of the code pulses of the signal X_ (O); Fp is the repetition frequency of

  code pulses reports Pl ... Pm.

  In the decoder, coding and decoding of stereophonic signals, the input of the demultiplexer (Figure 9) is driven by a sequence of binary characters of the coded digital sound broadcasting signal. The demultiplexer 130 carries out the clearing of the received digital bit stream of the following bit characters at the clock frequency Fs, the release, from the synchronization characters in received cycles, of a deblocking signal at the frequency Fd / N, and decomposing the received digital stream into character sequences of the coded words of the exponents and mantaines of the filtered coded signals and the half-sum signal of the left and right stereo channels. The character sequences of the coded words of exponents and mantissas are sent from the outputs of the (6 aZnbT;) Zt sanbTpienu saalîT; ap oolq np apauua anSe4e 'Pl aouanbgl; el e; UaATns as Tnb + X HepS np healthy-oal sap sapDs or ap aDuanbas e 5 sanbTuoqdoaaqs xneuBTs sael nod anapoo np (6 ainST;) 96 uodUxe uoT; 4seTo0UxU ap oo0q np aa9lqold np aS2aAUT 9aUaTqo2d al qnosa tEI uodCUe uoT7es ## EQU1 ## where TSUTV (0) X $ a + X [LUBRNS sanqoal sap sapoo s; or ap saouanbas ua 2asoduozap Oc anod papa.a inal quUsTlMa2 iú1 uodZe-; uoT; esteouxaaU ap oolq al suep quaATII (0) X 4a + X xnut5Ts sap sa2nqoal sap sapoo soux saI 'úú1 asa aAUT alP2oads uoTslaAuoD ap oolq np aeTqos Ul sTndaG sanbTuoqdouoU xneuBTs apapapapapapapapapapapapetapo z SDOIq sap uaGUauuoT; Duo ; al arLb uob; aaui ul ap qTp; as ZSI ana-uilo; uoo np a úgI 'CúúI' Zúi solq sap 'here apoz ap SnessTaaAUOD rnp 4uaaUuoT; ouo; ALU i a AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT AUT ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap ap X X X ap ap ap ap ap ap sanb7; t% sapuzq sap saseioads Sa UesodooD sap so2aZnu sae quzu2auoo ú91 aúIoJaUo ap ooiq np a ZS apierpu.oo ap suoTsindUT, p Inaqeuio; uoo rnp 991I 'LSI' 951 'SSI sasTos sal sTfndap qUVATIa Sl xnruBTS sal.ed apumuoD qsa 1Ui apOD ap 2naSSTqaAUOD np quea'auuo $ Tquo; aq sanlrbuoqdouou xnPubfs sap 2napoOap al suzp anLb; oaUU ap 'axT; aInbaTA V apoo ua (0) -X qe + X xnu5Tfs sap s8; aSmDads saquUsoduoo sap soolq led a; ue; o-; ainlBTA e apoo np UOTS.aAUOD 0i 21 zTe; As an apo ap anassT; AAUODO al suqa iI aenbTuoqdoalaqs IPuBTs np uoTqn; $ Tsa ap oolq np 10, I '' 10 jy saa2ua sal ans sTUIsUEq qus xrleU5Ts sal 'llll * tLE apoO ap S.ZnaSSTIaAUOD sal suep suULoI' axT; arln2IA U apoD ua aqu; ol; ############################################################################################################################################################################################################################################################ qaAuoo saq uLi. 'TLiú' here apoo ap s2nassT; qaauoD sap saluted sie ans 0ocI anaxaIdTinulap

6ZZ6ú9Z LS

58 2639779

  which differs from the digital filter block 97 in that it further comprises an auxiliary filter (m + 1) with a bandwidth of 0 to 0 Hz. Formed on the outputs of the digital filter block 142, the filtered signals X + (0) , X + (l) ... X + (m) are sent, respectively, to the inputs 1451 ... 145m + 1 of the stereophonic signal reproduction block 141. In addition, the input of the block 141 is attacked, since the output 144 of the buffer memory block 134, by the coded words of the

signal readings X_ (0).

  The stereophonic signal reproduction unit 141 realizes the reproduction of the signals of the left and right stereo channels according to the filtered signals X + (0), X + (1) ... Xm (1) of the half-sum of the left and right stereo channels. , according to the differential signal filtered in the low-frequency domain X_ (O0), and according to the values Pl ... Pm of the signal energy ratios of the left stereo channel to the sum of the energies of the filtered signals of the left channels and right. Then, in the frequency band from 0 to f0 Hz, the filtered signal of the left stereo channel is: XL (0) = X + () + x_ (o) (10) and the filtered signal of the right stereo channel is: X (O) = X + () - x (o) (11) Other filtered signals are reproduced according to the following relations: XL (i) = X + (i) Pi; (i = 1, 2, ..., m) (12) XR (i) = X + (i) (1 - PX (i) XL (i) (13) The complete restored signal of the left stereo channel will be: xL, = XL (= i) * (14) i = 0 and that of the right stereo channel and that of the right stereo channel:

59 2639779

  n XR - xP (Z) (Z) i = O In the stereophonic signal reproduction block 141, the coded words of the readings of the signals X + (0) and X_ (0) are sent to the inputs of the adder 212 ( 15), at the output of which are formed the coded words of the readings of the signal XL (0) arriving in the register 213. The coded words of the readings of the signals X + (0), X_ (0) are also sent to the inputs of the subtractor 214. from the output of which the coded words of the readings of the signal XR (0) arrive in the register 215. The coded words of the readings of the filtered signal X (1) attack the first input of the multiplier 2201 and the input of the register 2211 The second input of the multiplier 2201, which is the input 1401 of the block 141, is driven from the output of the code converter 1371 (Figure 9) by the code words corresponding to the ratio P1. The output of the multiplier 2201 (FIG. 15) provides the coded words of the reads of the filtered signal XL (1) of the left stereo channel arriving in the register 2211 and on the first input of the subtractor 2231. The second input of the subtractor 2231 is attacked by the coded words of the readings of the filtered signal XR (1) of the right stereophonic channel delayed in the register 2221 of a multiplication cycle. In the same way, the output of the filtered signals XL (2) ... XL (m), XR (2) ... XR (m) is realized. The registers 213, 215, 2221 ... 222m serve to delay the coded words of the signals XL (0), XR (0), XL (1)... XL (m) of a work cycle of the subtractors 2231. ..223m. The adders 217, 219 perform the addition of the filtered filtered signals XL (i), XR (i), oi = 0, 1 ..., m, attacking their inputs 216, 2241 ... 224m and 218, 2251. 225m, respectively. At the outputs of the adders 217, 219 are formed the coded words of the restored signals of the left stereo channels and

2639779

  right that attack the digital converters-

  Analogs 147, 150 (FIG. 9) and then low-pass filters 148 and 151. From the outputs of the filters 148 and 151, the restored signals of the left and right stereo channels arrive. Thus, at the output of the coder of the device, at the coding of the stereophonic signals, the stereophonic starting signal is represented by a digital stream transmitted with the speed:

+ V.

  VS = V + V, + Vp bits / s, (6) V is the speed of the digital signal of the half-sum coded signal Xr of the signals of the left and right stereo channels equal to the speed of the digital stream at the output of the encoder monophonic sound broadcasting signal; therefore: = (24.Kp + N.KM) .Fd / N bits / s; (17) Mo is the speed of the digital signal flow of the half-difference code X_ of the left and right stereophonic channels filtered in the frequency band from 0 to f0. As for the frequencies f> fo, the energy of the signal X_ (0) is equal to 0, its spectral components for which K> N1, o

= X-

  are also 0, and you do not need to code them; therefore the speed of the digital flow is then equal to: VV2 = ((24 - m) Kp + NlKM) .Fd / N bits / s, (18) om is the number of critical high frequency bands of the hearing o the ratios P1 ... Pm are calculated, Vp is the speed of the digital flow of the coded signals corresponding to the ratios Pl ... Pm and is equal to: Vp = m (K'p + K'M). Fd / N bit / s, (19)

2639779 where K'p and K'M are the number of bits respectively of the exponent and the

code mantissa

P1 ... Pm reports.

  In experimental studies of the claimed device, the passing frequency bands f0, f1 ... fn were chosen to be equal to the critical hearing bands. In this case, f0 = 6400 Hz, i.e. in the frequency band corresponding to twenty low frequency groups, the stereophonic effect is completely preserved. In each of the four remaining critical ears of hearing, a quasi-speech is assured. Since, in the high-frequency domain, human hearing practically does not perceive stereo sound, the introduction into the frequency range greater than 40 Hz of such quasi-phonophonie band is sufficient to preserve stereophonic perception. The parameters or.t were chosen as follows:

S = A5N M, = 412.

  Other parameters were chosen the same as the coding of monophonic sound broadcasting signals. In this case, the quality of the decoded stereo sound signal of sound broadcasting

  does not differ from the quality of the starting sound signal.

  The speed of the digital stream at the output of the coding device, according to the expressions (16), (17), (18) and (19), is equal to:

C +)

  VS = (4x4 + XI xO24) x3x) x / iO + _4 + 5x412) x x32x103 / 1024 + 4 (4 + 5) x32xIC3 / 1C2L = 225 kiDts / s, ie is 1.4 less than that of the coding device of the stereophonic signals where the signals of the left and right stereophonic channels are coded independently using the coding device described.

in claim 1.

62 2639779

Claims (2)

  1 - Device for encoding and decoding sound broadcasting signals, comprising: an encoder comprising, cascaded, a low-pass filter (1) whose input serves as input to the encoder and an analog-to-digital converter (2), and a code converter (6) electrically connected to the analog-to-digital converter (2), a synchronization pulse generator (21) being connected to synchronization inputs of the analog-to-digital converter (2) and the code (6); and a decoder having a code converter (29), and, cascaded, a digital-to-analog converter (32) electrically connected to the code converter (29) and a low-pass filter (33) whose output serves as an output at the decoder, a synchronization pulse generator (44) having an output (48) connected to the synchronization input of the digital-to-analog converter (32); characterized in that, for encoding and decoding monophonic sound-broadcasting signals, the encoder comprises: a buffer memory block (3) on the respective inputs of which are connected bit-by-bit the outputs of the analog-to-digital converter ( 2), while clock pulse inputs and clock cycles of the buffer memory block (3) are connected to respective outputs (22, 23) of the synchronization pulse generator (21); a block (4) for spectrally converting the sound broadcasting signals, whose information inputs are connected to the outputs of the buffer memory block (3), and clock cycle and clock pulse inputs are connected to the respective outputs (22, 23) of the synchronization pulse generator (21), the outputs of the spectral conversion block (4) of the signals are connected to its terminals Tnb (OC) uodCU; UOT1ST.XO'aUl ap DoCq a (6Z) apoD ap 2n9ssTq ^ aAuOd np qa (t) uoTqsTuo0qDuKs ap SuoTslndUtPt tihee alep s ^ aATqads92 S sepaqua sel ans aqtouleq; ua; p (g9) uoTwSTUO0qouAs apa ceptos its ap 9unl a, ( 6Z) apOD ap 2nessT; q2Auoo np seATDodsea sael; a salt ans saagqDulqquqq (9Z) anexaed; Tlnuap np uoTeulo; uT, p sa; .Ios sel '(9I) aneXaldT; nu nd; T2os UT ans aaqtqUq qSa e arnapoDap Oo nu aeaquep las apque8, l quop (9Ez) znaxaedT; Inuap a e: az odoo anapooap e9 'suo; tpUOD seaD suep "a: nepoo nee aoos aoqosas (91) anaxaedlInu np s! Qlos 21 q (IZ) UoTqesiuO0aDu / In this case, it is important to note that (91) 9Z anaexe! dTln; n np uoTqVsTuo0t2DuXs ap saVaqua sap '(6) apuwoo ep suoTsindUIp InsweeulouoD np seATqCedsax saTqos salt Ins sae-Ouvlq (0Z '61 ) apueuoD ap sae2; u9 sas qa '(9) apoD ap in9ssITqaAuoD np (8T' LT) seaTqos salt Sqn-lq uoT loouTp ssule its Trnb (91) oz naexald7lr.:i a e (IZ) uoesT-Suc ZouAS. p suoTSlrIdUTp i.aelaga5 nrp (úZ) eATOsasa aTI7oS UI lns apiqouuaq Ue; 9 t ano, 8 ap senbTn; To sepu2q sap saIeîa $ ods sauesod = oD Sep soapnu Sep-u2uu; uoo (ZI). aToUea 'oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo ; uoD np saATDoadsea saTq2os salt 2ns saaqoulq (gi '' I 'úI) apuieuroD ap sapaqua its Tnrb atno1i ap sanT'4TD sepueq sep seeiî; Dads 01 sequsodoo sep sozamnu sel uueuuauoD (ZT) aeToUie ap DoLq a t (9) epoo ep inessTlaAuoo np (S 'L) apu oOD ap s8aeeue sep 2ns saaqgueIq; uos saATDadsa seTq.oOs its qa (IZ) uoTq2sTuo. What do you think about this? "" "" "" "" "'' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' ap 2n8ssTqaeAUOD np UOTqUIO; uTp saea2Ua salt ans Tq ied xq 'seaaqDulq that; ealouos uoTsn ;;! poIp22 ap 6 Z6ú9Z ú9   connected bit-wise to the respective outputs of the code converter (29) and its synchronization inputs connected to respective outputs (48, 46) of the synchronization pulse generator (44) and the demultiplexer (26). ); a block (31) for inverse spectral conversion of the sound broadcasting signals which has its bit-bit connected information inputs on the respective outputs of the buffer memory block (30), its synchronization inputs connected to the respective outputs ( 48, 46) of the synchronization pulse generator (44) and the demultiplexer (26), and its connected bit-wise outputs on the respective inputs of the digital-to-analog converter (32); a control pulse shaper (34) having its sync inputs connected to the respective outputs (45, 46, 47) of the demultiplexer (26) and the sync pulse generator (44) having an appropriate output (47); ) is connected to the synchronization input of the code converter (29), the outputs (35, 36, 37, 38) of the control pulse shaper (34) being connected to the respective control inputs of the code converter (29), as well as inputs of the demultiplexer (26) and the buffer memory block (30); and a memory block (41) containing spectral component numbers of the critical bands of the hearing, which has its control inputs connected to the respective outputs (42, 43) of the control pulse shaper (34), its synchronization input to the corresponding output (46) of the demultiplexer (26), and its outputs (39, 40) connected to the information inputs of the control pulse shaper (34). 2 - Device for encoding and decoding stereo broadcasting signals comprising:   an encoder comprising, cascaded, a pass filter 2639779   main base (88) whose input serves as an input to the encoder and a main analog-to-digital converter (89), and a main code converter (109) electrically connected to the main analog-to-digital converter (89), a a synchronization pulse generator (123) being connected to the synchronization inputs of the main analog-to-digital converter (89) and the main code converter (109); and a decoder having a main code converter (131) and, cascaded, a main digital-to-analog converter (147) electrically connected to the main code converter (131) and a main low-pass filter (148) whose output serves as an output to the decoder, a synchronization pulse generator (154) having an output connected to the synchronization input of the main digital-to-analog converter (147); characterized in that, for coding and decoding broadcast stereo signals, the encoder includes, cascaded, an auxiliary low-pass filter (90) whose input serves as an auxiliary input to the encoder, and an analog converter an auxiliary digital unit (91) whose synchronization input is connected to the respective output (128) of the synchronization pulse generator (123), an arithmetic unit (93) having information inputs (92, 94) is respectively connected, bit by bit, on the outputs of the main and auxiliary analog-to-digital converters (S9, 91) and its synchronization input is connected to the respective output (128) of the synchronization pulse generator (123), a block digital filter system (97) having its information inputs connected, bit by bit, to the respective outputs of the arithmetic unit (93), and its synchronization input connected to the respective output (128) of the gen synchronization pulse generator (123), a block (99) of 66 2639779   conversion of signals carrying the information on the broadcasting stereophonic signal, having 2m groups of information inputs, om = 1 ... 24, respectively connected, bit by bit, on outputs (OO1 ... 100m, 100m +1 ... l * 1002m) of the digital filter block (97), and a group of bit by bit connected information inputs on respective outputs (98) of the arithmetic unit (93), and only entries. for synchronization which are connected to respective outputs (128, 129) of the synchronization pulse generator (123), auxiliary code converters (1031 ... 103m) which have their information inputs connected, bit by bit, on outputs (1021 ... 102m) of the signal converting block (99) carrying the information on the stereo signal radicdiffusicn, the synchronization inputs of the auxiliary code converters (1031 ... 103m) being connected to the respective outputs (128, 129) of the synchronization pulse generator (123), a multiplexer (105) having its bit-wise connected information inputs on outputs (113, 114) of the main code converter ( 109), its synchronization inputs connected to the respective outputs (124, 125, 127, 128, 129) of the synchronization pulse generator (123), the output of the multiplexer (105) serving as output to the encoder, each of the converters of auxiliary code (1031 ... 103m) having two groups of outputs connected to respective information inputs (1041 ... 104m, 106t ... 1C6m) of the multiplexer (105); as well as cascading with the arithmetic unit (93), the filter block (97) and said conversion block (99), a buffer memory block (96) which has a group of connected information inputs, bitwise on the respective output (95) of the arithmetic unit (93), and a second group of bitwise bit-connected information inputs on the respective output (101) of the block (99) of the agaqoupq, his qa anapooap does not apauap 4.as apa. zuajI quop (0CI) inaxaidT; inUap a: aqZodUoo 2napooap ael anb aD ua qa i (CZI) uoTqUSTuoaqouKs ap suoTslndUIT, p 5c nangequa5 np (gZI) aAT; 4adsa2 asT $ os el ans aptqqqqq, 2? a: nol ap sanbTqTIo sapueq sap salelaDads saquesoduoo sap sozagnu sal queuaquoD (gSiT) a.ZoUIau apoolq np uoIesTuoOlqtuXs ap a? 2ua, the (ZII) apuuuoD ap suo: sind! Tp zna-4lo; uoo np uoTI.lo; UTp saaaqua O sal ans saa-qDuPq (0ZI '611) saTqIos sas' a (ZlI) apUeJXOD ap suoTslndUTp inaeuilozuoo np SaAT; Dadsal saTZos sal Ins sa-Du2ueq (SIT 'LIT' 911) apu = oo ap sa; ua sas Z 7nb arno0, ap sanIbT; D sapu2q sap saie2Dads saquesod'oD ap so28aunu sal queua; uoD (glT) S azTo9aU ap jolq a; a: (gOi) znaxaldT; nd saga; ua sal irns (ZZi 'uZ) saT; qos ## EQU1 ## where: ## EQU1 ## (2) ## EQU3 ## lao (ú [E) uoTUsTuol4quAs ap sUoTsrindITp oza;. t5 0 E rp ('ZI' 9ZI '2Zl) saATrDadsal saTosos sal ans sagqUiq uo4 $ esTuoMDA's ap saalua ses' e Tnb (zEI) atu2oo ap suoTslnr .dTp anaqulo; uoo aleeleaEa queatcO'oD anapoo ai (601) lVdToUT.d apoo ap anassT; laAuoo np uoTquilo; uTp sagaua sal ans'; tq 'saqoDuleq quiea aaouos uoIsn ;; Ipoçpez ap xnrufbs sap ale2; qads uotslaauom ap (LOI) Doiq rp saTq2os sal' (úZI) uoT $ esTuoqoDuXs ap suoTsIndL, Tp rna; w: up5 rp (gzI 'EzI) saATqDadsa2 sai 2os sal ans saatqouuq aBoIotqp saloio ap -a5boIoqp 'UOTqSTUoloDUAS 0i ap saapzua sas' (96) uodmeL; uoT; esT2oaU ap ooiq np saTqIos sal ans' qTq 'tq' saat4uelq (soi) uoTo2u0; uT, p saazsua ses e Trb aZouos uOIsn ;; TpoTpiE ap xrn.uf5s sap ale-aeds uoTs2aAuoo ap (LOI) ooTq a; a (úEZI) uoi0 sIuo / qiuAs ap suoTsIrdUT, p inazeau? 5 np g (SZI 'bZI) saAT; DadsaatT; Sos saI years saaqoulq quieq (95) uodC; uoT; 1s! TOU1aU apoolq np UoTesTUo-qDUAs ap sa2qua sal 'uoTsn; JTpoTpU2 ap anibTuoqdo2aqs IPuBTs a year uoTq'alo; uT, I; u; .iod xneuFrs sap uoTs ^ aAuoO 6 // 6ú9E L9 68 2639? 779   the output of the multiplexer (105) of the encoder, the respective appropriate outputs (135, 136) of the demultiplexer (130) being connected to the information inputs of the main code converter (131) of the decoder and one of its synchronization outputs ( 164) being connected to the respective inputs of the synchronization pulse generator (154) and the main code converter (131) of the decoder; a first buffer memory block (132) which has its bit-bit-connected information inputs on the respective outputs of the decoder main code converter (131) and its synchronization inputs connected to the respective outputs (166, 167 ) of the synchronization pulse generator (154); an audio spectroscopic inverse signal spectral conversion block (133) which has its bit-bit connected information inputs on the respective outputs of the first buffer storage block (132), its synchronization inputs connected to the respective outputs (167, 166) of the synchronization pulse generator (154); a control pulse shaper (152) having its sync inputs connected to the respective outputs (164, 165) of the demultiplexer (130) and the sync pulse generator (154) and a suitable output (157) connected on the synchronization input of the decoder main code converter (131), the outputs (155, 156, 158) of the control pulse shaper (152) being respectively connected to the control inputs of the main code converter ( 131) of the decoder and the demultiplexer (130); a memory block (153) containing the numbers of the spectral components of the critical bands of the hearing which has its control inputs connected to the respective outputs (159,) of the control pulse shaper (152), its synchronization input connected to the. exit 692639779   respective ones (167) of the synchronization pulse generator (154) and its outputs (161, 162) connected to the information inputs of the control pulse processor (152); m auxiliary code converters (1371 ... 137m) each of which has two information inputs connected to the respective outputs (1381 ... 138r, 1391 ... 139 &) of the demultiplexer (130), the synchronization inputs of each m auxiliary code converters (1371 ... 137r) being respectively connected to outputs (168, 163) of the synchronization pulse generator (154) and the demultiplexer (130); a stereophonic signal reproduction block (141) which has its synchronization input connected to the respective output (16S) of the synchronization pulse generator (154); a digital filter block (142) which has its synchronization input connected to the respective output (168) of the synchronization pulse generator (154) and its outputs (m + 1) and the outputs of each of the m auxiliary codes (1371 ... 137n), connected, bit by bit, to inputs (1451 ... 145m + 1, 1401 ... 140m) of the stereophonic signal reproduction unit (141); a second buffer memory block (134) which has its bit-bit-connected information inputs on the outputs of the inverse sectral conversion block of the sound broadcasting signals (133) and its synchronization inputs, respectively, connected to the outputs (166, 167, 168, 163) of the synchronization pulse generator (154) and the demultiplexer (130), the outputs of an output group (143) of the second buffer memory block (134) being connected, bitwise, on the respective inputs of the digital filter block (142), and the outputs of another group of outputs (144) being connected, bit by bit, to the respective inputs of the stereophonic signal reproduction block (141). ); and, cascading, a 2639779   an auxiliary digital-to-analog converter (150), and an auxiliary low-pass filter (151) whose output serves as an auxiliary output to the decoder, the outputs of a group of outputs (146) of the stereophonic signal reproduction block (141) being connected , bit by bit, on the information inputs of the main digital-to-analog converter (147), and the outputs of its second group of outputs (149) being connected, bit by bit, to the information inputs of the auxiliary digital analogue converter (150), whose synchronization input is connected to the respective output (168) of the pulse generator of synchronization (154).