Asymptotic analysis of the multiuser MMSE receiver for the downlink of a MC-CDMA system

This paper considers multi-carrier CDMA (MC-CDMA) communication systems. Recently, the asymptotic performance of a multiuser MMSE receiver for a MC-CDMA system has been established, assuming orthogonal spreading codes and equal powers. A similar study has also been conducted for a DS-CDMA system, considering in this case unequal powers. The introduction of orthogonal codes can be considered as a breakthrough for the asymptotic analysis of such systems, and requires an intensive use of the free probability theory. Based on these results, we investigate in this paper the asymptotic performance of the multiuser MMSE receiver for a MC-CDMA downlink transmission, with orthogonal codes. The asymptotic value of the signal to interference plus noise ratio (SINR) is derived, as a function of the channel loading, the noise power and the power distribution μ_power(p). Simulations show that the asymptotic SINR is applicable to realistic systems.