一种降低OFDM峰均比的编码方法

讨论了一种降低正交频分复用(OFDM)系统峰均比的分组编码方法.对于4载波OFDM系统,通过对已有QPSK调制下具有最小峰均比(PAR)的码字进行分析,表明了能使峰均比降低至少3 dB的码字所满足的相位关系,并以此为基础,研究推广了这类码字在M-PSK调制下的一种一般获取过程.对于子载波个数增大的OFDM系统,讨论了以4载波编码方法为基础降低峰均比的办法,对其进行了理论分析并给出了仿真研究.仿真结果表明文中编码方法不仅能有效降低OFDM系统的PAR,而且具有一定的纠错能力.

A Block Coding Scheme for Reducing Peak-to-average Power Ratio in OFDM

In this paper we discuss a block coding scheme for reduction of peak-to-average power ratio (PAR) of an orthogonal frequency division multiplexing (OFDM) system. By analyzing the code words with the minimum PAR in OFDM system utilizing QPSK modulation and 4 carriers, the phase relationship that the code words satisfy is proposed, and the construction of these code words utilizing M-PSK modulation is discussed. With this coding scheme, PAR of OFDM system with 4 carriers can be reduced effectively. When the number of carriers becomes larger, a method based on the coding scheme of 4 carriers is discussed. The simulation results indicate that the block coding scheme proposed in this paper not only can effectively reduce the PAR in OFDM system, but also have the ability of error correction.