Accession Number : AD0828785

Title :   SIGNAL DESIGN FOR VECTOR CHANNELS.

Descriptive Note : Final rept.,

Corporate Author : IBM FEDERAL SYSTEMS DIV GAITHERSBURG MD

Personal Author(s) : Corr, Francis P. ; Davies, John M. ; Keeler, Robert E. ; Schwarz, Gordon R. ; Van Blerkom, Richard

Report Date : FEB 1968

Pagination or Media Count : 247

Abstract : The major objective of the investigations described in this report was to determine whether combinations of signals sent over more than one subchannel can increase transmission efficiency in the presence of noise and fading. Digital and analog coding techniques are included in the study. A wide range of techniques are discussed including digital coding and optimum signal design using the Pontryagin Maximum Principle. Two techniques which warranted more detailed study are Diversity Multiplexing and Fourier Transform Transmission. Diversity Multiplexing is an analog mapping (coding) technique whereby linear combinations of baseband signals are mapped with redundancy onto a vector channel. This technique is evaluated with respect to transmission over fading channels and crosstalk susceptibility. Fourier Transform Transmission (FTT) is a technique which appears to have interesting application to selective frequency fading channels. Burst correcting codes are used to bridge gaps in the received signal caused by frequency selective fading of the Fourier Transform of the signal. The advantages and disadvantages of both techniques are considered and FTT is recommended for further study and evaluation. (Author)

Descriptors :   (*CODING, MULTIPLEXING), INTEGRAL TRANSFORMS, RADIO TRANSMISSION, INFORMATION THEORY, PERFORMANCE(ENGINEERING), RADIO SIGNALS, ATTENUATION, RADIOFREQUENCY INTERFERENCE, OPTIMIZATION.

Subject Categories : Cybernetics
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE