Partial channel information feedback mechanism for FFR-based multi-channel systems

Abstract

This article puts forward a partial channel state information (CSI) feedback scheme for fractional frequency reuse (FFR)-based orthogonal frequency division multiple access (OFDMA) systems. Efficient CSI feedback strategy plays an important role in opportunistic scheduling because base station (BS) can employ adaptive modulation and coding (AMC) technique to adaptively change transmission rates according to CSI feedback, and therefore the spectrum efficiency can be improved significantly. On the other hand, FFR is a simple but effective technique to improve the throughput of users at cell edge. To exploit opportunistic scheduling in FFR-based OFDMA systems, both users and spectrum are divided into multiple groups in this article, and specific feedback pattern is designed for each user group on each spectrum sub-band. Simulations results prove that the proposed algorithm can reduce the feedback load significantly, while maintain nearly the same performance as the system with full feedback.