Accession Number : AD0710237

Title :   THE TIME DISPERSIVE CHANNEL AS A LINEAR ENCODER.

Descriptive Note : Final rept.,

Corporate Author : ARMY ELECTRONICS COMMAND FORT MONMOUTH N J

Personal Author(s) : Klein,Theodore J.

Report Date : JUN 1970

Pagination or Media Count : 126

Abstract : The problem considered in the report is that of reducing intersymbol interference caused by time dispersive channels. This is not a new problem, and much recent work has centered on the use of the Tapped Delay Line (TDL) equalizer. The conventional approach is to choose the no dispersion channel as the desired channel, and then to minimize some measure of the intersymbol interference. The approach described in this report recognizes the encoding properties of time dispersive channels. These channels process the transmitted data in much the same way as the generator of a cyclic algebraic code. Two methods of attack are taken. In the first method the code generator coefficients are used as the desired response for an otherwise conventional TDL equalizer. This method is termed the Coded Equalizer method. Transmission of k q-ary code word. Thus, error correction can be obtained with an ordinary algebraic decoder, and without transmission of parity symbols. In the second method the channel encoding is accepted without further processing by a TDL equalizer, to minimize the additive noise variance subject to the constraint that inter-symbol interference be eliminated. A modification of this method allows trading computation time for a limited amount of intersymbol interference. (Author)

Descriptors :   (*INFORMATION THEORY, SYMBOLS), (*DATA TRANSMISSION SYSTEMS, RELIABILITY(ELECTRONICS)), CODING, DECODING, ERRORS, MATRICES(MATHEMATICS), PULSE AMPLITUDE MODULATION, THESES

Subject Categories : Cybernetics
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE