Trade-off in Joint Communications and Sensing with Frequency Modulation Waveforms

Joint communications and sensing (JCS) can improve the efficiency of power, spectrum and hardware usages. The conflict between communications and sensing is analyzed in terms of bandwidth and power, for frequency modulation waveforms originally used in radar sensing. It is found that, when the communication receiver is also the sensing target, the bandwidth is approximately partitioned between communications and sensing, thus making an almost zero-sum game between communications and sensing. The same conclusion for bandwidth conflict still holds when the communication receiver and target are separated. The feasible region and trade-off boundary of JCS are obtained from numerical computations.