Subchannel power control in the OFDM system to improve BER performance under multipath channels

摘要

We propose a subchannel power control scheme in the OFDM system, which transmits data with a variable power level for each subchannel based on the received SNR. The OFDM system, employing the D-QPSK modulation and the proposed subchannel power control with a grouping coefficient equal to 3, gives about 2.3 dB gain in E_b/N_o comparing with the conven- tional OFDM system, under the two-ray mltipath channel with the mean value of the second-ray's attenuation coefficient equal to 0.25, for the required BER equal to 10~-5.