SU921099A2 - Digital adaptive corrector of intersymbol distortions in data signals - Google Patents

Description

(54) DIGITAL ADAPTIVE CORRECTOR OF INTERSIMBLE DISTORTIONS IN DATA SIGNALS

one

The invention relates to telecommunications, may be used for adaptive correction of intersymbol interference in received data signals.

According to the main author. St. No. 801269 is known a digital adaptive intersymbol distortion corrector in data signals, comprising an analog-digital converter, a memory unit, a software unit, a correlation unit, an arithmetic unit, and an analyzing unit of receiver 1.

However, the well-known digital adaptive equalizer does not provide a sufficiently high accuracy of the correction of intersymbol distortion of single-band and two-band data signals.

The purpose of the invention is to improve the accuracy of the correction of intersymbol distortion of single-band and two-band data signals.

. The goal is achieved by introducing an additional analog-to-digital converter, an additional arithmetic unit, a control unit, a digital signal analysis unit, a signal sample memory unit, a controller's transmission factor generating unit, and a digital-analog converter into the known digital adaptive equalizer, and the analog output -digital converter through a serially connected digital signal analysis unit and a unit for forming the transfer coefficients of the controllers connected to the input Additional arithmetic unit, the first output of the additional analog-digital converter through the control unit is connected to the input of the input block of the formation of the transfer factors of the regulators, to the input of the reference memory block and to the input of the additional arithmetic unit, the second output of the additional analog-digital converter through serially connected a memory block of signal samples and an additional arithmetic unit are connected to the input of a digital-to-analog converter.

The drawing shows a structural

2Q electrical circuit of the proposed digital adaptive equalizer.

Claims (1)

Digital adaptive intersymbol distortion corrector in Data signals contains corrector 1, analog-to-digital converter (ADC) 2, memory block 3. software unit 4, correlation unit 5, arithmetic unit 6, analyzing receiver unit 7, digital signal analysis unit 8, additional ADC 9, control unit 10, memory unit 11, signal samples, regulator transfer factor generating unit 12, additional arithmetic unit 13 and a digital-to-analog converter (DAC) 4, combined into a preliminary equalizer 15. The digital adaptive equalizer works as follows. The received signal from the channel output of the tone frequency is fed to the input of the preliminary equalizer 15, which has few taps and serves mainly to optimize the operation of the real time and clock oscillation systems. Based on the analysis of the signals at the output of the A / D converter 2 produced by block 8, the transfer coefficients of the tap adjusters of the preliminary equalizer 15, i.e. Preliminary correction of the frequency distortion of the communication channel is carried out. From the output of the pre-corrector 15, the signal goes to the receiver (not shown in the drawing) and from its output to the input of the ADC 2, in which the signals are gated at the reference time, the amplitudes of the received voltages are sampled and converted to P-bit code numbers. The obtained P-bit code numbers of the samples are recorded in block 3. In the same block 3 from the output of the analyzing block 7, the data on the polarity and amplitude of the signals at the output of the corrector 1 and the signals indicating the sign of their deviation from the nominal value, i.e. intersymbol interference in received MSI data signals). Based on the analysis of the signals output from block 3 by the commands of program block 4, and in accordance with the selected algorithm of operation of the corrector 1, block 3 produces signals about the direction of change of the transmission coefficient of the corresponding tap of the corrector 1, which are stored in block 3. In each operation cycle software block 4 from block 3 to the multiplication unit (not shown) of the arithmetic block b, two P-bit code numbers are received, corresponding to the modules and fields of the transmission and sampling codes for the corresponding Corrector Correction 1. The resulting products are recorded by the commands from program block 4 to the summation block (not shown) of the arithmetic block b. In the next cycle of operation of program block 4 from block 3, the code numbers corresponding to the next tap of the equalizer 1 are fed to the outputs of the arithmetic block b in arithmetic b are summed algebraically with the numbers stored in it from the previous clock cycle for the previous tap of the corrector 1. This the process continues until the sums obtained as a result of summing the products of the sampling codes and transmission coefficients for all the taps of corrector 1B are recorded in the arithmetic unit b during the adjustment process, in both equalizers 1 and 15, such transfer coefficients of tap regulators are recorded, at which the value of the MCI is minimal. Thus, the preliminary corrector 15 partially corrects the MCI in the received data signals and by correcting the frequency distortions of the communication channel optimizes the phase position of the carrier and clock oscillations extracted from these signals, which in turn improves the accuracy of the MCI correction by the digital adaptive equalizer . The invention is a digital adaptive corrector of intersymbol distortions in the data signals by aut. St. No. 801269, characterized in that, in order to improve the correction of intersymbol distortions of single-band and two-band data signals, an additional analog-to-digital converter, an additional arithmetic unit, a control unit, a digital signal analysis unit, a signal sample memory unit, a transmission factor generation unit were introduced controllers and a digital-to-analog converter, with the output of the analog-to-digital converter through a serially connected digital signal analysis block and a block forming unit the controller transfer effects are connected to the input of the additional arithmetic unit, the first output of the additional analog-to-digital converter is connected to another input of the controller forming factors transfer unit, to the input of the signal sample memory block and to the input of the additional arithmetic unit, the second output of the additional analog -digital converter through a serially connected memory block of signal samples and an additional arithmetic unit connected to the input of numbers Analog converter. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 801269 ,. cl. H 04 B 3/04, 1980 (prototype).