MIMO-OFDM系统中基于循环移位和信号联合的改进SLM算法

为降低多输入多输出正交频分复用(MIMO-OFDM, multiple input multiple output orthogonal frequency division multiplexing)系统中传统选择性映射(SLM, selected mapping)算法的计算复杂度，提出了通过信号时域循环移位和天线间信号联合产生更多具有不同峰均功率比(PAPR, peak to average power ratio)的备选序列集合的方法。接收端先根据发射端序列选取情况恢复出频域旋转信号，再比较反向旋转序列与最近星座点的距离来恢复原始序列。仿真结果表明，所提出的方法能有效地抑制MIMO-OFDM信号的PAPR。另外，与传统SLM算法相比，提出方法明显降低了计算复杂度，而且可以获得传统SLM方法在已知边带副信息情况下近似的比特误码率性能。

Modified SLM algorithm based on cyclic shift and signalcombination in MIMO-OFDM system

In order to reduce the computational complexity of conventional selective mapping (SLM) algorithm in multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) system, more candidate sequence sets will be produced. With different peak to average power ratio (PAPR) by time domain cyclic shift and signal combination between the antennas. The receiving part can restore the rotation signals by using the sequence selection order of the transmitting part and also the original signals by comparing the inversed rotation sequence with its nearest constellation points. The simulation results show that the proposed method can effectively reduce the PAPR of OFDM signals. In addition, compared with the conventional SLM algorithm, the proposed method can reduce the algorithm computation complexity significantly and obtain similar bit error rate (BER) performance.