A NOTE ON SEQUENTIAL DECODING APPLIED TO LARGE ALPHABET INCOHERENT CHANNELS-RCOMP DETERMINATION,

摘要

Interest in large alphabet signaling systems to which sequential decoding procedures can be applied has prompted an investigation of the computation cutoff rate for such channels. This report restricts itself to incoherent channels,where the meaning of 'incoherent'will be made precise presently. Suppose one of 1orthogonal and equal energy bandpass signals is sent over a channel perturbed by additive white Gaussian noise. The prior probability of all signals is assumed equal. The received signal is detected by a bank of 1filters matched to the 1waveforms. The envelopes of the filter outputs are formed and are sampled at the appropriate time. This detection procedure is optimum if the receiver does not have knowledge of the RF phase of the signal,and if the RF phase,whatever it is,is constant over the signaling interval. A decoder has available to it the 1analog outputs. A decision on the largest of these destroys information. Accordingly,if coding is to be used,it is appropriate to view the 1analog outputs as a vector which may be operated on by a decoder. (Author)