Adaptive modulation for V-BLAST systems with power constraints

Adaptive modulation for Vertical Bell Laboratories Layered Space-Time (V-BLAST) systems is considered in this paper with peak power constraints on each antenna besides the average total power limit on the entire system. The bit loading and power allocation of margin maximization problem and rate maximization problem is given by modifying the incremental allocation algorithm. The loading algorithm of combination of both fixed and variable rate services is presented as well. The results show that the power limit which is very practical for a real V-BLAST system saves the total energy of the whole system at a target bit error rate (BER), but decreases bit rate for rate maximization or deteriorates BER performance for margin maximization