PAPR reduction of OFDM using invasive weed optimization-based optimal peak reduction tone set selection

Ho-Lung Hung,Chung-Hsen Cheng,Yung-Fa Huang

doi:10.1186/1687-1499-2013-244

Abstract

Abstract Tone reservation (TR) is one of the attractive techniques to reduce peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing system. As conventional TR technique requires exhaustive searching over all the combinations of the given peak reduction tone (PRT) sets, it results in computational complexity that increases exponentially with the number of the subcarriers. In this paper, we aim to obtain a desirable PAPR reduction with low computational complexity. Since the process of searching the optimal PRT set can be categorized as combinatorial optimization with some variables and constraints, we propose a novel scheme, which is based on a nonlinear optimization approach named as invasive weed optimization method, to search the optimal combination of PRT set with low complexity. To validate the analytical results, extensive simulations have been conducted, showing that the proposed schemes can achieve significant reduction in computational complexity while keeping good PAPR reduction. As results of simulations, the proposed scheme shows almost the same PAPR reduction performance as compared with the genetic algorithm-based TR method which has been known to have the best performance and obtains near-optimal PRT sets.

Highlights

Orthogonal frequency division multiplexing (OFDM) has been attracting substantial attention due to its excellent performance under severe channel condition [1,2,3,4]
We propose a newly suboptimal peak reduction tone (PRT) set selection scheme based on a modified invasive weed optimization (IWO) algorithm, which can efficiently reduce the peak-to-average power ratio (PAPR) of the OFDM signals
The proposed IWO-particle swarm optimization (PSO)-based PRT position search algorithm can be summarized in Algorithm 2: 4 Results and discussions Let us proceed to the application of the IWO-based tone reservation method in OFDM PAPR reduction

Summary

Introduction

Orthogonal frequency division multiplexing (OFDM) has been attracting substantial attention due to its excellent performance under severe channel condition [1,2,3,4]. One of the major problems is its sensitivity to peak-to-average power ratio (PAPR) of transmitted signals, and some schemes have been proposed to reduce the PAPR in OFDM systems [3,4]. High PAPR results in a way that an OFDM receiver's detection efficiency becomes very sensitive to nonlinear devices used in a signal processing loop, such as digitalto-analog converter (DAC) and high-power amplifier, which may severely impair performance due to induced spectral regrowth and detection efficiency degradation [5,6].

Objectives

Results

Conclusion