Co-design of joint radar and communications systems utilizing frequency hopping code diversity

Most of the dual-function radar communications (DFRC) systems in the literature require a multi-sensor transmit array and assume a prior knowledge of several parameters, such as channel state information and accurate transmit array geometry. In this paper, we propose a new co-design strategy for joint systems between radar and communications with a single transmit antenna and no assumptions of any prior knowledge. The communication information embedding is achieved using the diversity of frequency hopping waveforms. The communication receiver detects the embedded symbols by estimating frequency components of the sub-pulses contained in one pulse, where Fast Fourier Transform (FFT) can be utilized. Assume that the discrete frequency coding deploys Q distinct, equally spaced frequencies and only one frequency is transmitted during one sub-pulse. There are Q! different frequency hopping orders, thus a data rate of megabits per second can be achieved for a moderate number Q of sub-pulses and a single transmit antenna. The possible data rate is analyzed and bit error rate using simulated and experimental data are provided for performance evaluations.