Accession Number : AD0690817

Title :   ERROR BOUNDS FOR DIGITAL COMMUNICATION OVER SPATIALLY MODULATED CHANNELS.

Descriptive Note : Technical rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS

Personal Author(s) : Greenspan,Richard Lewis

Report Date : 30 MAY 1969

Pagination or Media Count : 100

Abstract : The transmission of digital information by means of electromagnetic wave propagation between terminals is reconsidered in order to understand the influence of the radiation channel, including the terminal antennas, on the quality of communication that can be maintained. In particular, we investigate the potential to improve performance by modulating the messages onto a set of spatially varying patterns across the source antenna. We show that the radiation channel can be modeled by parallel combination of independent spatially and temporally modulated subchannels when the background noise at the receiver has Gaussian statistics and is uncorrelated at points separated by more than few wavelengths of the carrier frequency. Error bounds are evaluated for digital transmission with optimum distribution of signal power to the subchannels. These bounds are used to interpret the significance of the signal and channel parameters and the interplay among them. (Author)

Descriptors :   (*DATA TRANSMISSION SYSTEMS, *INFORMATION THEORY), DIGITAL SYSTEMS, ERRORS, ANTENNA RADIATION PATTERNS, OPTIMIZATION, OPTICAL EQUIPMENT, MODULATION, RADIO TRANSMISSION

Subject Categories : Cybernetics
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE