Department of Electronic Engineering, National Formosa University, Yunlin 632301, Taiwan.
Sensors (Basel). 2023 Jan 13;23(2):950. doi: 10.3390/s23020950.
Orthogonal frequency division multiplexing (OFDM) has the characteristics of high spectrum efficiency and excellent anti-multipath interference ability. It is the most popular and mature technology currently in wireless communication. However, OFDM is a multi-carrier system, which inevitably has the problem of a high peak-to-average power ratio (PAPR), and s signal with too high PAPR is prone to distortion when passing through an amplifier due to nonlinearity. To address the troubles caused by high PAPR, we proposed an improved tone reservation (I-TR) algorithm to alleviate the above native phenomenon, which will pay some modest pre-calculations to estimate the rough proportion of peak reduction tone (PRT) to determine the appropriate output power allocation threshold then utilize a few iterations to converge to the near-optimal PAPR. Furthermore, our proposed scheme significantly outperforms previous works in terms of PAPR performance and computational complexity, such as selective mapping (SLM), partial transmission sequence (PTS), TR, tone injection (TI), etc. The simulation results show that in our proposed scheme, the PAPR is appreciably reduced by about 6.44 dB compared with the original OFDM technique at complementary cumulative distribution function (CCDF) equal to 10-3, and the complexity of I-TR has reduced by approximately 96% compared to TR. Besides, as for bit error rate (BER), our proposed method always outperforms the original OFDM without any sacrifice.
正交频分复用（OFDM）具有频谱效率高、抗多径干扰能力强的特点，是目前无线通信中最流行、最成熟的技术。但是，OFDM 是一种多载波系统，不可避免地存在高峰均功率比（PAPR）的问题，信号的 PAPR 过高，通过放大器时由于非线性会容易发生失真。为了解决高 PAPR 带来的问题，我们提出了一种改进的音调保留（I-TR）算法来缓解上述现象，该算法将进行一些适度的预计算，以估计减少峰值音调（PRT）的大致比例，从而确定适当的输出功率分配阈值，然后利用几次迭代来收敛到接近最佳的 PAPR。此外，与选择性映射（SLM）、部分传输序列（PTS）、TR、音调注入（TI）等之前的工作相比，我们提出的方案在 PAPR 性能和计算复杂度方面都有显著的提高。仿真结果表明，在我们提出的方案中，与原始的 OFDM 技术相比，在互补累积分布函数（CCDF）等于 10-3 时，PAPR 降低了约 6.44dB，与 TR 相比，I-TR 的复杂度降低了约 96%。此外，对于误码率（BER），我们提出的方法在不牺牲任何性能的情况下始终优于原始的 OFDM。
