Adaptive Modulation with One Bit CSI in OFDM

A novel robust bit loading algorithm with uniform power constraint under desired rate for OFDM is proposed. In this algorithm, only strong subchannels are used to transmit data. The number of active subchannels is determined by a criterion named capacity criterion, then power is allocated among active subchannels. The most significant novelties of this algorithm are that two modulation schemes are used at most and only one bit channel state information (CSI) for each subchannel is needed to transmit back. It has low complexity, while it has familiar performance with that of Fischer´s algorithm. Our algorithm has obvious advantage in deep fade channel models. It is a promising technique in future wireless communication under TDD mode