基于交错方向乘子法的并行GPS信号捕获算法

信号捕获是GPS基带信号处理的核心组成部分，是影响GPS接收模块功耗和成本的重要因素。传统捕获算法处理数据量大、消耗资源多，该文利用压缩感知理论完成GPS信号捕获，将数据量降低到半码片捕获精度要求的门限之下，同时提出高效的并行捕获算法以降低运算量。具体而言，首先利用C/A码构造正交基，建立GPS信号捕获的压缩感知模型；其次，将该压缩感知问题纳入交错方向乘子法(ADMM)的框架，提出一种高效的并行捕获算法。在该算法中，压缩感知问题被分解成多个相对独立的子问题并行迭代求解，并且迭代的每一步都有简单的闭合解，因此运算量很低。仿真结果验证了该算法的正确性和有效性。

Parallel GPS Signal Acquisition Algorithm Based on Alternating Direction Method of Multipliers

Signal acquisition is one of the key tasks in global position system (GPS) baseband signal processing, which determines the power consumption and the hardware cost of GPS receivers. However, most conventional acquisition algorithms are based on the correlation operations, thus demanding a large amount of data and consuming lots of computational resources. To alleviate this, we propose an efficient parallel GPS signal acquisition algorithm in this paper, utilizing the idea of compressive sensing. Specifically, we first represent the GPS signals in sparse form by projecting the signal onto a base matrix consisting of the orthogonal C/A codes. Based on this sparse representation, a compressive sensing model of GPS signal acquisition is established. Then, we develop an efficient iterative parallel acquisition algorithm for the compressive sensing problem by fitting it into the framework of alternating direction method of multipliers (ADMM). Each iteration of ADMM can be computed in closed form, thus giving it very low complexity. The efficiency and efficacy of the proposed algorithm are validated by numerical simulations.