一种OFDM系统子载波及峰均比联合优化算法

A joint optimization algorithm for subcarrier selection and peak-to-average power ratio in OFDM systems

摘要:

正交频分复用作为无线通信中的一种核心调制技术，因其高频谱效率、强抗衰落能力以及稳定的传输性能而备受关注，然而OFDM系统中高峰均比问题会显著影响系统效率；同时，传统OFDM系统在所有子载波上传输信息，在严重频率选择性衰落信道中，深衰落频点处的子载波携带信息难以正确解调，这将导致系统误码率显著升高。为解决上述问题，提出了一种OFDM系统子载波及峰均比联合优化方法，根据具体的应用场景和信道状态动态调整所需子载波数目及位置，并结合PAPR抑制技术，以提高信号传输的可靠性；仿真结果表明提出方法不仅有效提升了误码性能，同时也显著降低了PAPR，从而优化了系统整体性能。

Abstract:

Orthogonal Frequency Division Multiplexing, as a core modulation technology in wireless communications, is highly regarded for its spectral efficiency, resilience to fading, and stable transmission performance. However, the high Peak-to-Average Power Ratio in OFDM systems significantly impacts system efficiency. Moreover, traditional OFDM systems transmit information over all subcarriers, which, in severely frequency-selective fading channels, results in subcarriers at deep fading frequencies carrying information that cannot be demodulated correctly, leading to a substantial increase in the system’s bit error rate. To address these issues, this study proposes a joint optimization method for subcarrier selection and PAPR in OFDM systems. The method dynamically adjusts the number and position of subcarriers according to specific application scenarios and channel conditions, integrating PAPR suppression techniques to improve transmission reliability. Simulation results demonstrate that the proposed approach effectively enhances BER performance while significantly reducing PAPR, thus optimizing overall system performance.