Dual-Function MIMO Radar Communications System Design Via Sparse Array Optimization (1808.04940v1)

Abstract: Spectrum congestion and competition over frequency bandwidth could be alleviated by deploying dual-function radar-communications systems, where the radar platform presents itself as a system of opportunity to secondary communication functions. In this paper, we propose a new technique for communication information embedding into the emission of multiple-input multiple-output (MIMO) radar using sparse antenna array configurations. The phases induced by antenna displacements in a sensor array are unique, which makes array configuration feasible for symbol embedding. We also exploit the fact that in a MIMO radar system, the association of independent waveforms with the transmit antennas can change over different pulse repetition periods without impacting the radar functionality. We show that by reconfiguring sparse transmit array through antenna selection and reordering waveform-antenna paring, a data rate of megabits per second can be achieved for a moderate number of transmit antennas. To counteract practical implementation issues, we propose a regularized antenna selection based signaling scheme. The possible data rate is analyzed and the symbol/bit error rates are derived. Simulation examples are provided for performance evaluations and to demonstrate the effectiveness of proposed DFRC techniques.

Dual-Function MIMO Radar Communications System Design Via Sparse Array Optimization

The paper "Dual-Function MIMO Radar Communications System Design Via Sparse Array Optimization" presents a detailed examination of spectrum congestion alleviation through the integration of radar and communication systems within a single Multiple-Input Multiple-Output (MIMO) radar platform. This integration is made feasible by sparse array optimization, where antenna selection plays a pivotal role.

Sparse Array Configuration and Communication Embedding

Significant interest is placed on the development of novel methods that exploit sparsely configured antenna arrays to embed communication data into radar emissions. The proposed methodologies ingeniously capitalize on the spatial diversity offered by sparse arrays alongside waveform diversity intrinsic to MIMO radar systems. The steering vectors of these sparse arrays serve not only radar tasks but also encode unique communication symbols.

The notion of deploying antenna selection and permutation of orthogonal waveforms to specific antennas enhances communication capabilities while maintaining radar functionality. By selecting subsets of antennas and permuting the waveform-antenna pairings, significant improvements in data rates are achievable without compromising radar operations—a bold assertion substantiated by their simulation results.

Numerical Analysis

The paper details strong numerical results, indicating that data rates of megabits per second can be achieved even with a moderate number of transmit antennas. Additionally, the introduction of regularized antenna selection modulates the typical Binary Phase Shift Keying (BPSK) bit error rates. Such strategies counter practical limitations that arise from ungainly antenna reconfigurations.

Simulation examples demonstrate a promising reduction in symbol error rates, achieved with different signaling strategies. Notable errors in communication symbol detection occurring at various signal-to-noise ratios (SNRs) and angles provide insights into the robustness and potential applications of the proposed techniques.

Practical Implications and Future Directions

The implications for this research span across improving radar and communication systems efficiency under constrained spectral environments. The dual-functionality promises advancements in shared spectrum usage, reducing the competitive need for distinct frequency allocations between systems—a crucial endeavor in increasingly dense communication environments.

From a theoretical standpoint, this paper foregrounds the potential for further exploration of spatial degrees of freedom (DoFs) within sparse arrays. Future developments may explore autonomous and dynamic antenna configuration within real-world scenarios, further enhancing system responsiveness without the burden of hardware constraints.

Overall, the authors contribute extensively to the understanding and practical application of array configurations in dual-function radar and communication systems, posing new avenues for exploration in spectral efficiency and hardware adaptability. Such contributions invite researchers to explore dynamic configuration methods, potentially influencing the next generation of MIMO radar solutions in commercial and defense communications.