综合孔径辐射计中二级相关算法的设计与实现

Design and implement of bi-stage correlation algorithm in microwave synthetic aperture radiometer

为了解决传统微波遥感辐射计使用FPGA实现多通道数字相关器时资源消耗量过大的问题,本文提出了一种二级相关实现方法。二级相关算法将相关算法分成前后两级,并利用门时钟生成单元使系统保持流型工作状态。前级相关器由基本逻辑资源构成,完成固定短点数的相关处理;多个前级相关器分为一组,分时启动并复用后级长点数相关器。二级相关算法能显著解决微波遥感辐射计中多通道数字相关器资源消耗量巨大的问题,提高数字相关器所容纳的相关通道数,同时优化了FPGA布局布线性能,能提高系统性能并降低成本。

To solve the large resource consumptionproblem when using FPGA to implement multiple channel digital correlator of microwave radiometer, this article proposes a bi-stage correlation algorithm. Bi-stage correlation divides correlation operation into two stages, and uses gated clock to make sure the system work continuously. First-stage correlator consists of basic logic resources and implements short fixed-point correlation; multiple fist-stage correlators are started in order andgrouped to timing share a second-stage correlator. Bi-stage correlation algorithm could solve the resource consumption problem in multiple channel digital correlator of microwave radiometer, increase channels in radiometer system, and optimizemapping and routing in FPGA, optimize system and reduce cost.