Design of Simplified Coherent QPSK Modem for Frequency Hopping Spread Spectrum

摘要

PSK coherent demodulation has difficulty in achieving high speed carrier extraction and symbol synchroniza- tion when implementing to slow FH-SS radio system. On the other hand, implementation to FPGA has the requirement of a small gate size to design because of FPGA cost issue. We devel- oped a QPSK coherent demodulation digital modem for FH-SS radio systems using FPGA by solving problems. The designed modem performs symbol synchronization with no carrier extrac- tions, under the limitation of the small gate size requirement.