A Novel Scheme for Channel State Information Feedback in MIMO-OFDMA System

The exceeding performance of Close-Loop MIMO scheme over Open-Loop one is attractive. However, the large size of Channel State Information (CSI) feedback to transmitter is its major drawback. To reduce this cost, many works have been done on CSI feedback design in frequency domain for MIMO-OFDM systems. We propose a scheme which represents the CSI in temporal domain. Based on that the channel is inherent formed by numbers of taps, it is efficient to take few dominant ones. Many multiuser systems take advantage of frequency diversity by allocating only subset of subcarriers to a user, so user can only send feedback on subcarriers of its preferred resource blocks. We improve our channel impulse response (CIR) feedback scheme to let the counterpart of temporal response by DFT focus on these resource blocks of interest (RBol). Performance evaluation has been taken on 3GPP Spatial Channel Model. Simulation shows that the performance of temporal response emphasized on RBoIs exceeds that of Channel Frequency Response with same size and is comparable to the Channel Frequency Response based scheme with higher frequency resolution.