支持载波聚合的高效多频功率放大器及线性化研究

项目名称： 支持载波聚合的高效多频功率放大器及线性化研究

项目编号： No.61201043

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 电子学与信息系统

项目作者： 陈文华

作者单位： 清华大学

项目金额： 28万元

中文摘要： 为了满足移动宽带业务的快速增长，载波聚合技术已成为下一代无线通信系统拓展带宽的有效手段，本课题着重研究支持载波聚合的高效多频功率放大器及其线性化技术。载波聚合技术需要射频前端具备多频段并行传输的能力，传统多个单频功放在大功率级进行信号合成的方法会带来较大损耗，导致整机效率下降。因此，本课题将研究支持载波聚合的多频段Doherty功放的设计方法，对主辅路功率分配比和栅极偏置电压进行联合优化，改善传统Doherty功放中回退区效率偏低的问题。多频功放中由于同时放大多个频段信号，其非线性特性将包含带内互调和带间交调，为了表征这些新出现的非线性分量，需采用多维非线性行为模型可对其精确建模，并解决由于频带间交叉调制引起的模型复杂度迅速增加问题。考虑到载波聚合信号的稀疏特性，本课题拟研究基于压缩采样的预失真技术，通过设计观测矩阵和信号恢复算法，实现低采样率的数字预失真平台，降低系统成本。

中文关键词： 载波聚合；Doherty功放；宽带功放；数字预失真；压缩感知

英文摘要： In order to meet the rapid growth of broadband wireless communication services, carrier aggregation has been trusted as a promising technique for bandwidth enhancement in the next generation wireless communications, this project will focus on the high-efficiency multi-band RF power amplifiers and related linearization techniques for carrier aggregation in LTE-Advanced systems. In carrier aggregation technology, the RF front-ends are required to have the capabilities of concurrent multi-band transmission, since the traditional method of signal combination at high power stage leads to a significant loss. Thereby, this project will study multi-band high efficient asymmetrcial Doherty amplifiers. To achieve the power added efficiencies at backoff region from the saturated power,a joint optimization scheme of the power division rate and gate bias voltages will be carried out for efficiency enhancement.Due to co-existance of the signals at different frequencies in the multi-band PAs, the distortions of PA will include intra-band modulation and inter-band modulation. To accommodate these nonlinear terms, a multi-dimension model will be proposed to accurately model the nonlinearities, and we will also provide solutions to compress the increasing model complexity induced by the new architecture. Considering the sparsity

英文关键词： Carrier Aggregation；Doherty PA；Broadband PA；Digital Predistortion；Compressive sensing