OFDM-based Joint Radar-Communication System: Optimal Sub-carrier Allocation and Power Distribution by Exploiting Mutual Information

In this paper, we present a novel joint radar-communication system which exploits orthogonal frequency division multiplexing (OFDM) waveforms for performing radar and communication operations simultaneously. A dual-purpose OFDM transmitter is exploited which optimizes the transmit power of different sub-carriers to fulfill the radar objectives. These OFDM sub-carriers used by the radar are also allocated to different communication receivers to achieve the communications objectives. The mutual information (MI) between the frequency-dependent target response and the transmit waveform is used as the optimization objective for radar performance. The communication performance is optimized by allocating the radar sub-carriers to different communication users by using MI maximization as the criterion. For the communication system, the problem has been discussed in terms of maximizing the overall MI as well as achieving the worst-case MI for each user. Two optimization strategies are discussed and compared which optimize the two systems respectively using a radar-centric design and a cooperative design. Simulation results illustrate the performance of the proposed strategies.