DOA estimation accuracy improvement for circular array interferometer with analog phase detector and its FPGA implementation

摘要

Circular array interferometer with analog phase detector requires higher signal to noise ratio than the digital phase detection structure, which leads to lower accuracy of direction-of-arrival (DOA) estimation. T o overcome this, we proposed two kinds of methods which can work together. They are the modified phase accumulation method (MPAM) and the optimal baseline pair method (OBPM). Modified phase accumulation method solves the problem caused by phase jump near ±π in analog phase detection structure in conventional phase accumulation method (CPAM). Taking the azimuth corresponding to one certain baseline pair as reference, OBPM outputs the azimuth and elevation corresponding to the highest accurate baseline pair. Simulation results show the effectiveness and correctness of these two methods. At last, we introduced the FPGA implementation about the two methods. By taking advantage of the parallel architecture, we saved the processing time.