Multiplex adaptativo por função de maioria e decisão suave.

Abstract

Soft-decision techniques have been used with some types of codes for several years, improving their error correcting capacity without adding extra redundancy. This thesis deals with the study and hardwa_ re implementation of a soft-decision technique applied to a code division multiplex system. This system,which has the cha_ racteristics of an error correcting code with variable redundancy, is based on Walsh functions. The multiplexing process produces a systematic variation of the intersymbolic influence of the digits, automatically increasing the error correc - ting capacity, as the number of active channels decreases. The basic theoretical description of the system, the circuits used and, a discussion of the results are presented.