Research On Precoding In MIMO System

Future mobile communication brings forward higher call for wireless communication system in the field of transmission rate, system and system business capacity. Multiple Input Multiple Output communication system is a wireless transmission system which adopts multiple transmits antennas and receives antennas. MIMO technology significantly improves the capacity of wireless communication systems. Precoding is one of the signal processing techniques which requires channel state information (CSI) at the transmitter, which can increase the capacity or decrease the bit error rate (BER).Linear precoding for single and multi-user channels in MIMO system with perfect CSI at the transmitter is studied in this thesis. The former studies ZF and MMSE precoding. On this basis, MMSE precoding performance based on LDPC codes is studied. The latter linear precoding designs based on maximal SJNR criterion. This method takes into consideration of both the CCI and noise at the same time. And therefore, it can effectively improve the system performance.Linear precoding technique based on two models for MIMO system with imperfect CSI at the transmitter. Using the channel mean feedback model, this paper improves the traditional water filling algorithm and study a joint power allocation and adaptive modulation scheme. Using the limited feedback model, we discuss how to design the codebook and choose the optimal codeword from the codebook. The simulation results indicate that the limited feedback system achieves almost the performance of the system with perfect CSI.In order to test and verify the algorithm that the thesis puts forward, and lay the foundation for the project of the algorithm practically,the thesis have designed Embedded MIMO precoding platform system on the basis of Windows CE include EP9315 processor of ARM9 in the last part, The code experiment platform, has described the software and hardware design process of the experiment platform in detail, and discussed the MIMO precoding algorithm technology system on the basis of the platform.