Power Allocation Method for OFDM System with both Total and Per-Antenna Power Constraints

In this paper, we propose an optimal power allocation method for OFDM system with both total transmit power constraint (TTPC) and per-antenna power constraint (PAPC). In contrast to traditional water-filling method, the new one takes into account of the signal distortion caused by PAPC in deducing system capacity, therefore can achieve a more accurate allocation between multiple sub-channels. Simulation results confirm that the new method can better reduce signal distortion and maximize system capacity, especially when the signal power approaches the limit of PAPC.