Blind detection in IDMA systems

Interleaved Division Multiple Access (IDMA) is a new access scheme that has been proposed in the literature to increase the capacity of wireless channels. The performance of such systems depends on the accuracy of the channel state information (CSI) at the receiver. In this paper, a Noisy-Independent Component Analysis (NICA) based IDMA receiver for multiple access communication channels is proposed and compared to classical receivers. The N-ICA component is applied as a post processor. The estimation of CSI will often have some measurement errors, which degrade the accuracy of symbol detection. Using blind methods, this overhead can be eliminated. Simulation results demonstrate that N-ICA post processor provides an improvement in performance in terms of bit error rate (BER) in loaded systems and it offers an efficient alternative to systems with block channel estimation. When the system is not loaded, the proposed post processor presents the same performance as conventional IDMA receiver with less iterations leading to a complexity reduction.