We propose the OFDM system with a subchannel power control, which transmits data with a variable power for each subchannel based on the received SNR. The OFDM system, employing a subchannel power control with a grouping coefficient equal to 3, gives about 3 dB gain in E/sub b//N/sub 0/ compared with the OFDM system without the subchannel power control, for either coherent or noncoherent QPSK modulation under the two-ray multipath channel with the mean value of the second-ray's attenuation coefficient equal to 0.3, for the required BER equal to 10/sup -5/.
['Hongku Kang', 'Wooncheol Hwang', 'Kiseon Kim']
OFDM systems with subchannel power control under the two-ray multipath channel