A novel interference cancellation technique for MIMO CC-CDMA system

This paper presents a novel multiple-input-multiple-output (MIMO) code-division-multiple-access (CDMA) communication system, which utilizes a combination of mutually orthogonal complete complementary (CC) codes (CC-CDMA) for data spreading and a suitably designed multiuser detector (MUD). The proposed MIMO CC-CDMA system successfully eliminates multiple access interference (MAI), multipath interference (MPI), and spatial interference (SPI) that combined degrade current MIMO CDMA systems, operating in time-dispersive (i.e. frequency-selective) mobile fading channels and using conventional Walsh spreading codes. Simulation results obtained are twofold. First, they reveal significant improvement in bit-error-rate (BER) performance, and consequently the achieved capacity compared with a conventional Walsh codes based CDMA (Walsh-CDMA) system. Secondly, they show approximately similar BER performance with different number of codes (or code length) used, which may facilitate the mixing of users with different rates services without compromising on the system performance.