Partial CSI feedback scheme for subchannel allocation in multiuser OFDM systems

An efficient partial feedback scheme is proposed for the subchannel allocation in the multiuser OFDM systems to minimize the system power consumption under the constraints of the overall target throughput and bit error rate. The conventional feedback schemes only send back the minor subchannels´ information or compress the channel information to few bits. There is a large margin left corresponding to the full feedback scheme. In this paper, we propose a method to derive the channel state information (CSI) for the null feedback subchannels from the best-n and lowest-1 feedback information. For the flat fading Rayleigh channel, the pretreatment of the feedback CSI can provide the approximate full knowledge of the channel state. And then the power and subchannels are allocated to the users adaptively. The simulation results show that the pretreatment method greatly enhances the performance than the conventional best-n scheme, and comparing with the other pretreatment method, the proposed scheme provides an efficient and less complexity solution.