文中介绍了QPSK调制解调的原理，并基于FPGA实现了QPSK调制解调电路。MAX+PLUSII环境下的仿真结果表明了该设计的正确性。 -In this paper, the principle of QPSK modulation and demodulation, and a FPGA-based QPSK modulation and demodulation circuit. MAX+ PLUSII environment simulation results show the corr

介绍了某直接序列扩频、QPSK调制系统接收通道中四相Costas 载波跟踪环的原理及其基于 DSP+FPGA 的实现-Introduced a direct-sequence spread spectrum, QPSK modulation system, receive path Costas carrier tracking loop four-phase principle and its implementation based on DSP+ FPGA