Multi Carrier-CDMA based SDR using Super Orthogonal Turbo Code

Multi Carrier-CDMA, a combination of CDMA and OFDM has become a promising access technique for next generation wireless communication. It offers high speed data rate, flexible bandwidth allocation and enhanced performance to each user simultaneously. To further realize the benefits of MC-CDMA, it is made adaptable in the physical layer of software defined radio (SDR) where SDR is defined as a reconfigurable hardware with inbuilt software modules. Thus a MC-CDMA system based SDR is constructed which can be best suited for developing standards. However, as the number of users increases, due to overlapping of signals, orthogonality of the OFDM part is not maintained. It results in multiple access interference (MAI) which degrades the system performance in the downlink. To mitigate these effects, multi user detection techniques (MUD) is used. In this paper, MC-CDMA based SDR using super orthogonal turbo code (SOTC) is proposed and compared with MC-CDMA using Walsh Hadamard (WH) codes. The bit error rate (BER) is evaluated using the two codes and performance analysis is observed.