Design and Implementation of a Fully Flexible Cognitive Radio Modem

—Software-defined radio (SDR)-based cognitive communication radio systems are very popular at present, and there have been many investigations on this topic. This paper proposes a new type of cognitive radio transceiver (TRX) that can detect, recognize, and analyze input signals in real-time with minimal data loss. New hardware is designed and manufactured that combines a transmitter and a receiver in a dedicated integrated circuit. For data processing, a field-programmable gate array (FPGA) is used. For each integrated hardware block, appropriate software modules are developed to construct a complex adaptive radiocommunication system as a radio modem that can be configured as a transceiver or repeater. The source coder, channel coder, modulator, spectrum monitoring module, spectrum analyzer, channelizer, symbol rate detector, modulator, modulation type recognition module, demodulator, channel decoder and source decoder are all developed as software modules.