a systematic aproach to peak-to-average power ratio in ofdma systematic ap.docxVIP

A Systematic Approach to Peak-to-Average Power Ratio in OFDM对OFDM峰均比的研究Curt Schurgers Mani B. SrivastavaElectrical Engineering Department, University of California at Los Angeles (UCLA)ABSTRACT摘要OFDM multicarrier systems support high data rate wireless transmission using orthogonal frequency channels, and require noextensive equalization, yet offer excellent immunity against fading and inter-symbol interference. OFMD多载波系统支持高数据频率的无线传输，其采用的正交频率信道不需要广泛均衡却能提供出色的抗衰落和符号间干扰性能。The major drawback ofthese systems is the large Peak-to-Average power Ratio (PAR) of the transmit signal, which renders a straightforwardimplementation very costly and inefficient.这个系统的主要缺点是传输信号有很大的峰均比，这导致了这个非常直接的方法相当昂贵并且低效。Existing approaches that attack this PAR issue are abundant, but no systematicframework or comparison between them exist to date. 现在有非常丰富的办法来降低峰均比，但是目前在它们之间没有一个系统的框架和比较。They sometimes even differ in the problem definition itself andconsequently in the basic approach to follow. 它们有时甚至在问题的定义本身和基本的步骤都有不同。In this work, we provide a systematic approach that resolves this ambiguity andspans the existing PAR solutions. 现在，我们提供一个系统的途径来解决这些现有的降低PAR方法的模糊和跨越。The basis of our framework is the observation that efficient system implementationsrequire a reduced signal dynamic range. 我们的框架的基础是对有效的系统的实现进行观察，这需要降低信号的动态范围。This range reduction can be modeled as a hard limiting, also referred to as clipping,where the extra distortion has to be considered as part of the total noise tradeoff. 这个范围的缩小可以被表示为一个有着严格限制的模型，也被称为削波，其中额外的失真被视为总噪音的一部分。We illustrate that the different PARsolutions manipulate this tradeoff in alternative ways in order to improve the performance.我们以不同的方法说明了这些不同的降低PAR的方式是如何控制以提高性能。Furthermore, we discuss andcompare a broad range of such techniques and organize them into three classes: block coding, clip effect transformation andprobabilistic.此外，我们将对这些比较广泛的技术进行讨论和比较，并且将他们分为三类：块编码，削波，降低峰值概率。1. INTRODUCTION介绍Orthogonal Frequency Division Multiplexing (OFDM) belongs to the more general cl