Bandwidth, Carrier Frequency, and Waveform Optimization for Sensing and Communications in a Distributed Radar Network

We propose joint radar and communications bandwidth and carrier frequency allocation (BWCFA), and radar waveform optimization algorithm for a network consisting of a central coordinator and distributed radar nodes that operate in a monostatic mode. Considering that target related information (TRI) acquired by a node, which observes low signal-to-clutter and noise ratio (SCNR), can be equally important as that acquired by the node that observes high SCNR, maximization of the minimum of the SCNRs (Max-min approach) is proposed under the constraints on minimum range resolution and communications capacity, and the available system bandwidth. This optimization is non-convex and intertwined with the problems of optimizing radar waveforms, assigning bandwidths and carrier frequencies to nodes, and determining their optimum values. However, assuming that each node allocates contiguous and non-overlapping bandwidths for its radar and communications operations, considering that SCNR is a monotonically decreasing function of bandwidth and carrier frequency, and utilizing explicit relations between bandwidth and carrier frequencies for radar as well as communications, we approximately solve the overall joint optimization problem in two steps. The radar waveforms are first optimized, and then the resulting objective function is utilized for solving BWCFA with the geometric programming (GP). Computer simulations show that the proposed waveform optimization and BWCFA (WO-BWCFA) outperforms random waveform with BWCFA (RW-BWCFA) and waveform optimization with equal bandwidth allocation (WO-EBWA) algorithms.