A new multiuser diversity scheme exploiting detection order for AM-OSIC system

We propose a new detection ordering scheme and multiuser diversity scheme, which minimizes an average error rate occurring in a MIMO system using only adaptive modulation technique applied to an ordered successive interference canceller (OSIC). We simplify an optimal scheme in the view point of error rate by using approximated error rate. Though the complexity is reduced by only maximizing a minimum equivalent SINR, scaled by modulation indices, the simplified scheme demonstrates the almost same performance as the optimal scheme. Owing to the selection diversity of detection ordering, the proposed scheme produces over 3dB SNR gain at the BER of 10^-3 than the existing ordering schemes in the case of the 2×2 MIMO system with small amount of feedback information. We also propose the multiuser diversity scheme based on the proposed detection ordering scheme to improve average error rate of multiuser system. Here, multiuser diversity gain is obtained from the effect of user selection by the proposed scheme.