非线性功放条件下的恒包络OFDM系统性能

Performance of constant envelope OFDM system with nonlinear power amplifier

正交频分复用技术具有较高的频谱效率和好的抗频率选择性衰落性能,被广泛应用于无线通信系统中。但是OFDM信号具有较高的峰均比,当系统采用非线性功放时,OFDM系统需要较大的输入功率回退以避免信号失真。为了研究非线性功放条件下的系统性能,分析了恒包络OFDM系统的实现方式,并以误码率为指标,在加性高斯白噪声信道和多径衰落信道场景下对比了恒包络OFDM系统与采用传统迭代限幅滤波PAPR抑制技术的OFDM系统的性能。

Orthogonal frequency division multiplexing technology is widely used in wireless communication system due to its high spectral efficiency and good resistance ability to frequency selective fading. But it has high peak-to-average power ratio. Therefore, OFDM system needs large input power back-off to avoid signal distortion when using nonlinear power amplifier. In order to study the performance of the system under the condition of nonlinear power amplifier, the implementation of constant envelope OFDM was analyzed. Taking bit error rate as an index, the performance comparison between CE-OFDM system and OFDM system using traditional iterative limiting filter PAPR suppression technology were given under additive white Gaussian noise channel and multipath fading channel.