Collaborative Research: Low Peak to Average Power Multicarrier Signals via Coding: Fundamental Limits and Algorithms

协作研究：通过编码实现低峰值平均功率多载波信号：基本限制和算法

• 批准号: 0728572
• 负责人: Vahid Tarokh
• 金额: $ 4.5万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0728572&HistoricalAwards=false
• 关键词: Collaborative; Research; Low; Peak; Average; Collaborative; Research; Low; Peak; Average

One of the most important obstacles in deployment of high data rate, low cost, and power efficient multicarrier communication systems is the cost of front-end RF amplifiers. Multicarrier modulations offer the promise of low complexity equalization, adaptability to frequency selectivity of the channel, and efficient use of available bandwidth in cognitive networks. However, multicarrier signals consist of linear superposition of many subcarriers leading to large peak to average power ratio (PAPR) and implying the need for highly linear power amplifier. In particular, RF power amplifier becomes substantially power inefficient and expensive when its linearity region increases to accommodate signals with large PAPR. Any nonlinearity introduced by the power amplifier can cause large out-of-band leakage and reduce the transmit range of the link.While the worst case PAPR is quite large, it has been established by the investigators that the likelihood of having large peaks is small and there exist codes of almost full rate with PAPR bounded by a constant. Existing coding schemes, however, provide low PAPR and large minimum distance at the cost of substantially reducing the transmission rate. This research involves addressing both existential and algorithmic aspects of coding schemes for PAPR reduction. This research develops both probabilistic techniques and new algorithms to prove the existence and to construct pragmatic codes that not only provide low PAPR and high rate but also lead to optimizing other parameters such as capacity loss, minimum distance and out-of-band leakage.

部署高数据速率，低成本和电力效率的多载波通信系统的最重要障碍之一是前端RF放大器的成本。多载波调制提供了低复杂性均衡，对通道的频率选择性的适应性以及认知网络中可用带宽的有效使用。但是，多载波信号包括许多子载波的线性叠加，导致峰值与平均功率比（PAPR）较大，并意味着需要高度线性功率放大器。特别是，当RF功率放大器的线性区域增加以适应具有较大PAPR的信号时，功率放大器将变得效率低下且昂贵。功率放大器引入的任何非线性都可能导致带外泄漏并减少链路的发射范围。尽管最坏的情况是PAPR很大，但研究人员已经确定，具有大峰的可能性很小，并且在PAPR界定的速率几乎完全由常数界定。但是，现有的编码方案可提供低papr和较大的最小距离，其成本大大降低了传输速率。这项研究涉及解决PAPR减少的编码方案的存在和算法方面。这项研究既开发概率技术和新算法，以证明存在并构建实用代码，这些代码不仅提供较低的PAPR和高率，而且还导致优化其他参数，例如容量损失，最小距离和带外泄漏。