Performance enhancement of MC-CDMA system using LDPC codes

A turbo block code (TBC) technique for improving the performance of a multi-carrier code division multiple access (MC-CDMA) system in terms of bit error rate (BER) is proposed in this paper. The objective of this work is to develop a coding scheme that generates low BER code-words. By implementing a time domain TBC, designed using powerful low density parity check (LDPC) code, the BER performance of MC-CDMA system is improved and the same is proved through simulation. Two types of LDPC codes, viz. random LDPC codes and quasi cyclic (QC) LDPC codes are analyzed. These codes also have error correction capability along with high performance efficiency in terms of BER. In addition a decoding algorithm with moderate decoding complexity and with feasible soft output generation is also proposed for each LDPC code.