Study On Radio Minitor Technology Based On Software Defined Radio

The paper studies the technology of software-defined radio (SDR) and radio monitoring and designs the radio monitoring system based on SDR technology. Array signal received by the antenna is transferred to digital intermediate frequency in order to reduce the request of the system by the signal collection circuit, digital down convert circuit, high-speed signal process circuit, logic control circuit and output circuit. The intermediate frequency signal is dealt with by signals number determining, direction of arrival (DOA) estimation, beam forming and focus to separate the transient signal and steady signal, the former contains the character signal of radio station which can be identified by FM analyzing method, the latter can identify the radio signal of a certain radio station with auto identification modulation method based on decision-theory. The process is studied by using MATLAB simulation.