A peak-to-average ratio suppression method of ofdm signal based on nonlinear companding function

Abstract

The invention discloses a method for suppressing a peak-to-average power ratio of an OFDM signal based on a non-linear companding function, which method mainly solves the problems of the prior art in fixed parameter selection and low suppression performance of signal peak-to-average power ratio. The method comprises implementation steps as follows: 1) performing up-sampling upon an OFDM modulation signal to obtain an original OFDM signal; 2) selecting a non-linear companding function and setting an initial value of an iteration parameter; 3) performing companding conversion upon the original OFDM signal by using the companding function; 4) converting the signal subjected to companding to a frequency domain for frequency domain filtering, and then converting to a time domain so as to obtain a transmission signal, calculating the peak-to-average power ratio of the transmission signal; 5), judging whether iteration is finished according to the iteration parameter, if yes, obtaining the transmission signals that meet requirements on the peak-to-average power ratio (PAPR) of a system, otherwise, continuing to iterate. The method is capable of significantly reducing the peak-to-average power ratio of the OFDM signal with a little impact on BER (bit error rate) of the system, and can be applied to all kinds of new generation wideband OFDM wireless 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 a wireless orthogonal frequency division multiplexing OFDM modulated transmission signal, and can be widely applied to various new-generation broadband OFDM wireless communication systems. Background technique [0002] Orthogonal frequency division multiplexing OFDM modulation is a multi-carrier modulation technology. Because the subcarriers in the system are orthogonal, it can significantly reduce the intersymbol interference of the system. Compared with single carrier modulation, its spectral efficiency is higher . In addition, OFDM technology can better resist multipath channels by inserting guard intervals. Due to these advantages, OFDM technology has been widely used in wireless communication systems. However, the main disadvantage of OFDM technology is that the signal has a peak-to-average ratio PAPR characteri...

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Problems solved by technology

For example, Tao Jiang proposed a nonlinear companding method in "Exponential Companding Technique for PAPR Reduction in OFDM Systems". The basic idea is to convert the amplitude distribution of the original OFDM signal into a uniform distribution. However, this method will make the small amplitude The distribution of signals and large-amplitude signals increases, which leads to a decrease in peak-to-average ratio PAPR and bit error rate BER performance, and the parameter selection of this method is relatively fixed, and real-time adaptive adjustment cannot be performed based on actual signals

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