An analysis for MC- DS CDMA using optimized coding technique

Abstract

This paper addresses Concatenation coding scheme for Multicarrier Direct Sequence Code Division Multiple Access (MC DS CDMA). It is to support high capacity & utilizing less power among all sub channels. While using Multicarrier Code Division Multiple Access (MC CDMA), it only spreads codes in frequency domain, but main disadvantage is no code orthogonality. MC DS CDMA Signal is generated by serial-to-parallel converting the data symbols into N sub streams and applying Direct Sequence Code Division Multiple Access (DS-CDMA) on each individual sub-stream. It spreads both in Time and Frequency domain (TF Domain). MC-DS CDMA has the highest degrees of freedom in the family of CDMA schemes that can be beneficially exploited during the system design and reconfiguration procedures. A Concatenation Code concept is proposed to analyze and develop the MC-DS-CDMA. In coding theory, concatenated codes form a class of error-correcting codes that are derived by combining an inner code and an outer code. It gives solution to the problem of finding a code that has both exponentially decreasing error probabilities with increasing block length polynomial-time decoding.