Shared power allocation among subcarriers of OFDM systems

Orthogonal frequency division multiplexing (OFDM) has several properties which make it an attractive modulation scheme for high speed wireless transmission links. In this paper, a novel power sharing technique is proposed for different users to improve the system performance. The proposed technique is based on use of variable amplitude of subcarriers (VAS). Power can be increased to the users who are crossing the reference boundary (RB) and moving farther towards foot print (FP) of a cell. In this way the users having weak SNR can sustain their call even in multipath fading environment. Assuming knowledge of the instantaneous channel gain estimation for all users, we propose an OFDM dynamic adaptive subcarriers scheme to maintain optimum SNR level of the subchannels which are in deep fade. Simulation results show that the performance of the proposed algorithm is much better than that of other algorithms.