Peak-to-average power ratio inhibition method for orthogonal frequency division multiplexing (OFDM) signal

Abstract

The invention discloses a peak-to-average power ratio inhibition method for an orthogonal frequency division multiplexing (OFDM) signal. Through the method, the problems of fixation in the selection of parameters and low inhibition performance of signal peak-to-average power ratios in the prior art are solved. The method includes the following steps of: 1) up-sampling an OFDM modulating signal to obtain an original OFDM signal; 2) selecting a companding function and setting an initial value of an iteration parameter; 3) performing companding transformation on the original OFDM signal by using the companding function; 4) transforming the signal subjected to companding to a frequency domain for frequency domain filtering, transforming to a time domain to obtain a transmission signal, and calculating the peak-to-average power ratio of the transmission signal; and 5) judging whether iteration is finished or not according to the iteration parameter, if so, acquiring the transmission signal which meets the peak-to-average power ratio (PAPR) requirements of a system, and otherwise, continuing to iterate. According to the peak-to-average power ratio inhibition method, the peak-to-average power ratio of the OFDM signal can be reduced obviously under the condition of little effect on the bit error rate (BER) of the system, and thus, the peak-to-average power ratio inhibition method can be used for a new generation of various broadband 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 technology has the advantages of high spectrum efficiency and effective suppression of multipath fading and inter-symbol interference. Popular technologies in . OFDM modulation divides the signal sequence into N parallel sequences, and each parallel sequence modulates 1 subcarrier. The bandwidth occupied by each subcarrier is smaller than the relevant bandwidth of the channel. Therefore, the signal experiences a frequency non-selective channel. However, since the OFDM signal is composed of multiple independent sub-carrier signals, this causes a ...

AI Technical Summary

Problems solved by technology

However, since the OFDM signal is composed of multiple independent sub-carrier signals, this has caused a serious shortcoming in the OFDM system: when multiple sub-carrier signals have the same phase, a higher peak will be generated through mutual superposition. Average ratio PAPR

However, this method only optimizes the peak-to-average ratio of the signal, but cannot simultaneously control the BER performance of the system and the performance of out-of-band spectrum spreading; and the companding parameters in this method are fixed values, which cannot be real-time based on actual signals. adaptive adjustment

Modern iterative filtering rules adopt an iterative structure, and reduce the peak-to-average ratio of the signal through multiple limiting filters. Using the iterative process, multiple system performances can be jointly optimized and controlled, but the number of iterations required is large, which will greatly increase System Computational Complexity

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