A Near-Optimal Multiuser Detector for MC-CDMA systems Using Geometrical Approach

Amor Nafkha (1) , Christian Roland (1) , Emmanuel Boutillon (1)

1 LESTER - Laboratoire d'Electronique des Systèmes TEmps Réel

An efficient sub-optimal algorithm, called HIS (Hyperplane Intersection and Selection) detection algorithm, is proposed to solve the problem of joint detection of K users in a MC-CDMA system. Compared to the existing solutions, the proposed algorithm has three characteristics very attractive for pratical systems. Firstly, it has nearly optimal performance. Secondly, it has a low computational complexity (O(K^2) multiplications and O(K^3) additions). Third, the algorithm has an inherent parallelism. To our knowledge, the HIS algorithm is not just an add-on to a previous existing algorithm but a rather new decoding technic based on a singular value decomposition of the channel matrix H. After giving the equation of the MC-CDMA multi-user detection problem, the HIS algorithm is described. Its performance is compared to known existing algorithms (ZF, MMSE, PIC and Sphere Decoding). For a BER as low as 10^-4 the HIS algorithm introduces only 0.2 dB degradation compared to the optimal Sphere Decoding algorithm for K = 16 users againt 3.8 dB for the PIC (with two MMSE stages) algorithm

Mots clés: VLSI; Architecture; Turbo code; slice; high speed; interleaver

Amor Nafkha, Christian Roland, Emmanuel Boutillon. A Near-Optimal Multiuser Detector for MC-CDMA systems Using Geometrical Approach. ICASSP, 2005, Philadelphia, United States. pp.877-880. ⟨hal-00068921⟩