Method for suppressing peak-to-average power ratio (PAPR) of wireless OFDM (orthogonal frequency division multiplexing) signal based on signal amplitude distribution correction

Abstract

The invention discloses a method for suppressing the peak-to-average power ratio (PAPR) of a wireless OFDM (orthogonal frequency division multiplexing) signal based on a signal amplitude distribution correction, mainly used for solving the problems of low design flexibility and bad error rate performance in the prior art. The method comprises the following realization steps of: (1) performing an OFDM modulation on an input bit stream, then upsampling to obtain an original OFDM signal; (2) establishing a companding function according to the correction target of a signal amplitude distribution, and performing a companding transform on the original OFDM signal; (3) transmitting a companding transform signal, and calculating the PAPR thereof; (4) calculating a decompanding function, and performing a decompanding transform on a receiving signal; and (5) downsampling a decompanding transform signal, and performing an OFDM demodulation then counting an error rate. The method for suppressing the PAPR of a wireless OFDM signal based on a signal amplitude distribution correction disclosed by the invention can obtain a good compromise between the PAPR and the error rate performance, and can flexibly transform to satisfy the performance demands of different systems; and the method can be widely applied to various new generation of broadband wireless OFDM communication systems.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, relates to a peak-to-average ratio (PAPR) suppressing method of orthogonal frequency division multiplexing OFDM modulated wireless transmission signals, and can be widely applied to various new-generation broadband OFDM wireless communication systems. Background technique [0002] Due to the advantages of high spectral efficiency, anti-multipath fading and low implementation complexity, OFDM modulation technology has attracted more and more attention in many applications. However, one of the main defects of the OFDM system is that the peak-to-average ratio PAPR is too high. If the peak-to-average ratio is too high, the power amplifier in the transmitter is required to have a large linear dynamic range to avoid the distortion of the transmitted signal caused by nonlinear distortion. The increase of BER caused by spectral diffusion and in-band distortion increases the difficulty and ...

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Problems solved by technology

Tao Jiang proposed the exponential companding method in "Exponential Companding Technique for PAPR Reduction in OFDM Systems". The basic idea is to transform the amplitude distribution of the original OFDM signal into a uniform distribution. However, the uniform distribution goal pursued by this method will make The distribution of large-amplitude signals increases, so when a power amplifier with a large nonlinearity is used at the transmitting end, its bit error rate BER performance will deteriorate sharply; OFDM Signals With Nonlinear Companding Scheme” proposed a segmented companding method. The basic idea is to make the amplitude of the small signal after companding obey the Rayleigh distribution, and the amplitude of the large signal obey the uniform distribution. Although this method can effectively reduce the peak-to-average ratio of the signal PAPR, and the system bit error rate BER is also low, but it is difficult to change flexibly to meet the performance requirements of different systems; for this reason, Shiann-Shiun Jeng proposed in "Efficient PAPR Reduction in OFDM Systems Based on a Companding Technique With Trapezium Distribution" The basic idea of ​​the trapezoidal companding method is to convert the amplitude distribution of the original OFDM signal into a trapezoidal distribution. However, this method will increase the distribution of small-amplitude signals or large-amplitude signals under different parameter values. Peak-to-average ratio PAPR performance or bit error rate BER performance degradation

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