Research on QPSK Carrier Synchronization Algorithm Based on Software Defined Radio

Carrier synchronization is one of the key technologies of digital wireless communication. As a kind of four phase shift keying modulation method, QPSK has strong anti-interference ability of the suppressed carrier, which is widely used in digital wireless communications. On this basis, this article describes a Costas-loop coherent carrier extraction algorithm based on Arctangent phase detection. It designs a digital intermediate frequency receiver system based on software radio thought. The system consists of data acquisition module, digital down converter (DDC) and digital demodulation module. At last, it makes simulation verification by Matlab for QPSK demodulation. Simulation results show that the simulation model could correctly implement BPSK signal demodulation.