Embedding Communication Signals into the Radar Transmit Waveform

A joint radar-communication (JRC) system with both radar sensing and communication abilities is proposed to improve spectrum utilisation efficiency. The transmitter of the JRC consists of multiple antenna subarrays transmitting orthogonal waveforms. If the communication receivers are in radar sidelobe directions, the communication data symbols are embedded in the magnitude ratio as well as the phase shift between transmit waveform pairs. In the case of the communication receivers in radar main lobe direction, the data symbols are embedded in the phase shift between transmit waveform pairs only to preserve optimum radar target detection performance. Novel symbol mapping constellation scheme is designed to achieve a high data transmission rate while maintaining a relatively low symbol error rate. The simulation results show that with medium pulse repetition frequency radar waveforms used, the data transmission rate of the proposed JRC system is in the range of Mbits/s.