Emerging Prototyping Activities in Joint Radar-Communications

The previous chapters have discussed the canvas of joint radar-communications (JRC), highlighting the key approaches of radar-centric, communications-centric and dual-function radar-communications systems. Several signal processing and related aspects enabling these approaches including waveform design, resource allocation, privacy and security, and intelligent surfaces have been elaborated in detail. These topics offer comprehensive theoretical guarantees and algorithms. However, they are largely based on theoretical models. A hardware validation of these techniques would lend credence to the results while enabling their embrace by industry. To this end, this chapter presents some of the prototyping initiatives that address some salient aspects of JRC. We describe some existing prototypes to highlight the challenges in design and performance of JRC. We conclude by presenting some avenues that require prototyping support in the future.Comment: Book chapter, 54 pages, 13 figures, 10 table

A Blender-based channel simulator for FMCW Radar

Radar simulation is a promising way to provide data-cube with effectiveness and accuracy for AI-based approaches to radar applications. This paper develops a channel simulator to generate frequency-modulated continuous-wave (FMCW) waveform multiple inputs multiple outputs (MIMO) radar signals. In the proposed simulation framework, an open-source animation tool called Blender is utilized to model the scenarios and render animations. The ray tracing (RT) engine embedded can trace the radar propagation paths, i.e., the distance and signal strength of each path. The beat signal models of time division multiplexing (TDM)-MIMO are adapted to RT outputs. Finally, the environment-based models are simulated to show the validation.Comment: Presented in ISCS2

Subspace-Based Detector For Distributed Mmwave MIMO Radar Sensors

peer reviewedIn this paper, we present a generic signal model applicable to various distributed radar setups, encompassing both phased array (PA) and MIMO radar configurations. We consider a range of waveform modulation methods, including TDM, BPM, DDM, and fast time CDM. We devise a GLRT based detector for scenarios where the interference consists of colored noise plus a signal in a low-rank subspace and prove that the designed detector is CFAR. We demonstrate that when the CPI time is similar for the systems, the PA radar system exhibits better detection performance than MIMO, irrespective of the waveform modulation approach adopted. However, if the CPI time of the PA system is divided to the number of transmit waveforms utilized in the MIMO radar case (to account for the time needed for a PA radar to scan all angles), then in the presence of non-uniform interference, MIMO techniques, except TDM, surpass the performance of PA. Conversely, in cases of uniform interference, the performance of both MIMO techniques and PA are equivalent.U-AGR-7062 - BRIDGES2020/15407066/MASTERS (01/07/2021 - 30/06/2024) - MYSORE RAMA RAO Bhavani

A Coordinate Descent Framework to Joint Design of MPSK Sequences and Receive Filter Weights in MIMO Radar Systems

In this paper, we aim at a joint design of M-ary Phase Shift Keying (PSK) - or MPSK - transmit waveform and receive space-time filter to maximize the Signal to Interference plus Noise Ratio (SINR) in colocated Multiple Input Multiple Output (MIMO) radar systems. The design problem is formulated into a maximization of the SINR, including unimodular discrete phase constraint on the transmit waveforms. The resulting problem is non-convex, whereby we devise an iterative algorithm based on the Coordinate Descent (CD) framework to tackle it iteratively. To reduce the computational complexity in designing the transmit waveforms, we exploit the properties of Fast Fourier Transform (FFT) in this paper. Numerical examples illustrate the superior performance of the proposed algorithm in comparison with the state-of-the-art counterparts

Designing Interference-Immune Doppler-Tolerant Waveforms for Radar Systems

peer reviewedDynamic target detection using linear frequency modulation (LFM) waveform is challenging in the presence of interference for different radar applications. Degradation in the signal-to-noise ratio is irreparable, and interference is difficult to mitigate in time and frequency domains. In this article, a waveform design problem is addressed using the majorization-minimization framework by considering peak sidelobe level (PSL)/integrated sidelobe level (ISL) cost functions, resulting in a code sequence with Doppler-tolerant characteristics of an LFM waveform and interference-immune characteristics of a tailored polyphase sequence (unique phase code + minimal ISL/PSL). The optimal design sequences possess polynomial phase behavior of degree Q among its subsequences and obtain optimal ISL and PSL solutions with guaranteed convergence. By tuning the optimization parameters such as degree Q of the polynomial phase behavior, subsequence length M, and the total number of subsequences L, the optimized sequences can be as Doppler tolerant as LFM waveform in one end, and they can possess small cross-correlation values similar to random-phase sequences in polyphase sequence on the other end. The numerical results indicate that the proposed method is capable to computationally design chirplike sequences, which, prior to this work, were obtained by mimicking phase variations of LFM waveform. An application of the proposed method for the automotive scenario is also illustrated in the numerical results