Research On Uplink MIMO Detection Algorithm For LTE FDD

Multiple Input Multiple Output (MIMO) technology has been used as a key technology for 3G Long Term Evolution (LTE) in order to meet the need for high capacity and high reliability of the new generation. Virtual MIMO technology is used in LTE FDD uplink to increase the capacity, in which several orthogonal users share the same time-frequency resources, so the use of MIMO detection algorithms at the receiver separating different users is a necessity. But it is found that the existing detection algorithms in LTE FDD uplink have low bit error rate (BER) performance by analyzing those algorithms such as zero forcing (ZF),minimum mean square error (MMSE),etc. So it is necessary to do deep research on MIMO detection algorithms.In view of the poor BER performance of the existing algorithms, MIMO detection algorithms for LTE FDD uplink are deeply studied in this thesis. First, some basic algorithms such as QR decomposition-based MIMO detection algorithm are applied to LTE FDD uplink. Then, based on analyzing the successive interference cancellation (SIC) and the parallel interference cancellation (PIC), this thesis proposes two improved algorithms which are suitable for LTE FDD uplink: SIC based on sorted QR decomposition and CRC-based PIC. These two detection algorithms cancel the detected signals from the received ones, inhibit propagation of errors and improve the detection performance and system BER performance. At last, the BER performance of the existing detection algorithms is compared with the improved algorithms through MATLAB simulation in this thesis. The simulation results also demonstrate that the two improved detection algorithms have better BER performance than the existing detection algorithms.