SLM (selective mapping) method for reducing PAPR (peak to average power ratio) of MIMO-OFDM (multiple input multiple output-orthogonal frequency division multiplexing) system

Abstract

The invention provides an SLM (selective mapping) method for reducing a PAPR (peak to average power ratio) of an MIMO-OFDM (multiple input multiple output-orthogonal frequency division multiplexing) system. During a processing procedure of a transmitting end, only one IFFT (inverse fast fourier transform) algorithm and one operation of cyclic shifting and adding and subtracting of a time domain signal are needed, and thus the computation complexity is largely lowered; during a processing procedure of a receiving end, cyclic shifting of a time domain of a transmitting signal corresponds to reverse phase rotation of a frequency domain of a receiving signal, and a modulating signal is recovered by comparing distances between a reverse rotation sequence and a nearest signal constellation point; meanwhile, according to the SLM method, only a selection situation of a selected transmission signal in a certain set is sent as sideband information, and as the sideband information is constant, half-blindness detection is realized. Only a little of sideband information is transmitted, and an original signal can be recovered at the receiving end, so that the utilization efficiency of a frequency spectrum is improved.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, in particular to an SLM method for reducing the PAPR of a MIMO-OFDM system Background technique [0002] As we all know, the multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM for short) system obtains diversity gain by using frequency, time and different antennas, which can effectively resist multipath and noise in wireless communication, and become the future mobile One of the main candidate technologies for multimedia communication. [0003] The MIMO-OFDM signal is a multi-carrier modulation signal, and one of the main disadvantages is that the ratio of signal peak power to average power, referred to as Peak-to-Average Power Ratio (PAPR) is relatively high. At present, a mainstream method to reduce the peak-to-average power ratio of MIMO-OFDM system is selective mapping method (SLM method for short). The basic principle of the traditional SLM ...

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Problems solved by technology

The disadvantages of the traditional SLM method are: 1) In order to obtain better PAPR suppression performance, each antenna usually needs to select a signal with the smallest PAPR from multiple candidate signals for transmission, and each candidate signal needs to be transmitted by IFFT The modulation is obtained, and the computational complexity of the algorithm increases with the increase of the number of candidate sequences; 2), in order for the communication system to recover the original signal correctly at the receiving end, the transmitting end needs to transmit the sideband side information of the phase factor, the sideband The transmission of side information reduces the spectrum utilization efficiency of the system

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