Comp In Multi-user Mimo Scheme

The real carrying capacity between LTE (WiMAX) / IMT-A and 3G is not reflected in the peak rate but the capability of the ubiquitous mobile broadband wireless. Some operators even quantified the objectives for the "seamless 1Mbps". It is essential that improving the cell edge rates significantly for the quality of this seamless experience for users (Seamless QoE).With the fast improvement of processing capability at base station (BS) and the increase of the backhaul capacity, coordinated multi point communications with cooperative processing among BS have drawn significant amount of interest in recent years. Coordination between the base stations allows the quality of edge users to be greatly enhanced, and meets the objectives of the seamless experience for users. Among a big cellular MIMO system, multiple BSs change to a big super BS through a central unit. A clustered BS cooperation is proposed, which concludes full cooperation within the cluster, so as to increase sum rate; and limited cooperation in the inter-clustered area, so as to suppress the interference of edge users of cluster. For those systems of less capable BS and less low backhaul capability, adaptive intercell interference cancellation (ICIC) is proposed to reduce the complexity. The principle question is whether it is better to do ICIC or simply do standard single-cell beamforming.The employed metric are sum rate and throughput. It is shown that a small cluster size (about 7 cells) is sufficient to obtain most of the sum rate benefits, and channel state information (CSI) requirement is greatly reduced. Simulations show that the proposed coordination strategy efficiently reduces interference and provides a considerable sum rate gain for cellular MIMO networks. Adaptive ICIC strategy showed that beamforming is appropriate for all the users when the edge SNR is lower than 0dB; and ICIC is preferred when the edge SNR is higher than 10dB, such as in urban areas; on the medium SNR, adaptive ICIC is proposed, whose performance is better than static ICIC strategy. It provides great throughput gain, and requires less feedback.