说明：  基于FPGA的多功能对讲机通信系统设计基于FPGA的多功能对讲机通信系统设计基于FPGA的多功能对讲机通信系统设计
(FPGA-based multi-functional radio communication system design FPGA-based multi-functional radio communication system design FPGA-based multi-functional radio communication system design )