Blind equalization using cumulant based MIMO inverse filter criteria for multiuser DS/CDMA systems in multipath

Chi and Chen (see IEEE Trans. Signal Processing, July 2001) previously reported a blind equalization algorithm using cumulant based multi-input multi-output inverse filter criteria (MIMO-IFC) for mulituser DS/CDMA systems in multipath. Assuming that the user of interest is the weak user with signal power ε₁ and signal powers of all the interferers are identical, denoted ε, the performance of Chi and Chen´s algorithm is superior to that of Tsatsanis and Xu´s(see IEEE Trans. Signal Processing, vol.46, no.11, p.3014-22, 1998) blind minimum variance (MV) equalizer for low near-far ratio (NFR) (=ε/ε₁⩾1). In this paper, two blind equalization algorithms, called Algorithms 2 and 3, also using cumulant based MIMO-IFC are proposed. The former (Algorithm 2) can improve the performance of the MV equalizer. The latter (Algorithm 3) based on the former performs as well as Chi and Chen´s algorithm for low NFR and outperforms Chi and Chen´s algorithm and the MV equalizer for high NFR. Some simulation results are presented to support the efficacy of the proposed algorithms