Research Of Cooperative Multi-cell Pre-coding

With limited channel state information (CSI) of the mobile stations (MS), base stations (BS) cooperate to preprocess the transmission, improving the bit error rate (BER) performance, spectral efficiency, and becoming one of the research focuses in the field of wireless communications. Revolving around removing the co-channel interference (CCI) and optimizing the throughput, this paper investigates the cooperation pre-coding schemes in depth and does related simulation analysis. The main contents are as follows:(1) The main statistical properties of the MIMO channel are outlined based on the multi-cell cellular structure. For multi-user MIMO systems, different scheduling algorithms are investigated and analyzed on supporting the system throughput and ensuring the edge users’ fairness via simulations.(2) Linear pre-coding are investigated. Zero-forcing (ZF) and beam-forming schemes are introduced. For the power allocation of linear pre-coding, due to the iterative water filling (IWF), the optimal throughput is capable and the simulation shows the superiority of the algorithm. On this basis, the improved beamforming strategy based on CSI feedback is proposed, which is verified feasibly via the simulation on removing the CCI and improving the throughput.(3) Based on the multi-cell transmission, an improved interference ZF technique is proposed for a compromise between the throughput and interference removing. A collaborative block diagonalization scheme via CSI feedback is proposed and verified superior by simulation on removing the CCI and improving the throughput. Based on the beamforming, collaborative beamforming scheme with maximizing the signal to leakage plus noise ratio (SLNR) is investigated and verified feasible. A strategy based on the optimization of collaborative BS group is proposed, which is verified capable on improving the throughput break performance. Through simulations the proposed strategy is proved a good compromise between spectral efficiency, the algorithm complexity and the user’s fairness with good practical value. The compromised strategy based on the PMI feedback is studied and the simulation shows it to inhibit the edge users’adjacent-cell interference and increase the throughput performance. Finally, a number of issues about the cooperation pre-coding techniques are prospected.