基于变步长LMS算法的Costas环在FPGA上的实现

摘要

为了满足现代通信环境对短波接收机越来越高的要求，基于传统的科斯塔斯（Costas）环，设计了一种基于变步长LMS算法的科斯塔斯（Costas）环，并将这种科斯塔斯（Costas）环通过FPGA进行实现，以完成载波同步。通过调用Altera公司提供的IP核来进行系统设计，不仅使系统变得更加灵活，而且提高了系统的运算速度。最后，通过搭建DSP+FPGA平台，完成了整个接收机的设计。将QPSK信号输入系统，提取出基带信号，验证了系统的可靠性，证明其满足了对接收机的设计要求。%To satisfy the increasingly high requirement of modern communication environment for short-wave receiver, the Costas loop based on avariable-step LMS algorithm is designed, and implemented via the FPGA platform. And with IP core from Altera , the designed system could make the system more flexible while improving the operation speed. Finally, by building up the DSP+FPGA platform the design of the whole receiver is completed. With QPSK signal input to the system and by extracting the baseband signal, the reliability of the system is verified. All this indicates the satisfaction of requirement for receiver design.