User grouping algorithm for power minimization in STBC MC-CDMA systems

In this paper, we propose user grouping algorithms to provide power minimization in grouped STBC MC-CDMA systems. Depending on the channel fading conditions, power control is utilized to minimize the total transmitted power under a BER constraint. When the allocation is performed without a fair data rate requirement, we provide the optimal solution to the minimization problem. However when some fairness is considered, the optimal solution requires high computational complexity. We solve this problem by proposing two suboptimal algorithms. Simulation results illustrate a significantly reduced power consumption in comparison with other techniques.