Low complexity basis selection algorithm for per-common basis rate control

Considering per-common basis modulation and coding scheme at the transmitter and successive interference cancellation at the receiver, the active basis subset and the corresponding decoding order are determined where equal powers are allocated to the active bases. We first take into account a maximum likelihood decision strategy in which the optimal active basis subset and its decoding order are jointly determined such that the system capacity is maximized among all possible decoding orders over all possible basis subsets. We then propose a serial decision procedure consisting of a successive process that tests whether basis selection gain exists or not when the basis with the lowest post-processing SINR is discarded at each stage. The serial decision procedure that simply drops the worst basis at each stage leads to the globally optimal solution with considerably reduced complexity. Numerical results show that the proposed serial decision procedure induces no capacity loss compared with the maximum likelihood decision strategy.