A Joint Feedback Reduction Scheme Using Delta Modulation for Dynamic Channel Allocation in OFDMA Systems

Abstract

A novel feedback-reduction scheme is proposed for dynamic channel allocation (DCA) in OFDMA systems. Applying this delta-modulation (DM)-based scheme to the channel gain of adjacent subcarriers reduces the feedback information to 1 bit per subcarrier. Since this reduced feedback information can lead to performance degradation in the form of an increased bit error rate (BER), a modified amplitude craving greedy (ACG) method and improved DM are jointly adopted to minimize the loss. Simulation results verify that the proposed scheme can decrease feedback information by a factor of 1/M while retaining performance comparable to the full feedback case, which requires M bits per subcarrier as feedback information.