OFDM系统中低复杂度相位因子优化PTS算法

A Low Complexity and Phase Optimization Algorithm for PTS in OFDM Systems

部分传输序列(partial transmit sequence, PTS)算法能够有效降低正交频分复用(orthogonal frequency division multiplexing, OFDM)系统的峰均比(peak to average ratio, PAPR),但算法的计算复杂度较高。针对这一问题,提出了低复杂度的相位因子优化的部分传输序列算法(reduced calculation-partial transmit sequence, RC-PTS)。上述算法在系统发送端对时域数据乘以相位旋转因子来减少计算复杂度,在系统接收端依据数据星座点欧氏距离最大的原则,给出优化后的相位因子的表达式。仿真分析了所提算法的峰均功率比(peak to average power ratio, PAPR)抑制、计算复杂度降低比(computational complexity reduction ratio, CCRR)和系统误比特率(bit error rate, BER)性能,仿真结果表明,所提算法不仅明显降低了计算复杂度,而且有效抑制了OFDM信号的PAPR,算法的BER性能与原始信号的基本一致。

Partial transmission sequence algorithm(PTS) can effectively reduce the peak-to-average ratio(PAPR) of orthogonal frequency division multiplexing(OFDM) systems, however, the computational complexity of the algorithm is high. To solve this problem, in this paper, a low complexity phase factor optimized partial sequence algorithm(RC-PTS) is proposed. The algorithm reduced the computational complexity by multiplying the time-domain data by the phase rotation factor at the transmitter, and gives the optimized expression of the phase factor at the receiver according to the principle of maximum Euclidean distance of data constellation points.The peak-to-average ratio(PAPR) suppression, computational complexity reduction ratio(CCRR) and system bit error rate(BER) performance of the proposed algorithm were simulated. It shows that the proposed algorithm not only reduces the computational complexity significantly, but also effectively suppresses the PAPR of OFDM signals. The BER performance of the algorithm is basically consistent with the original signal.