Cognitive Sub-Nyquist Hardware Prototype of a Collocated MIMO Radar

TL;DR

This paper introduces a hardware prototype of a sub-Nyquist collocated MIMO radar that reduces sampling rates significantly while maintaining effective signal recovery, demonstrating practical implementation and real-time performance.

Contribution

It presents the first hardware implementation of a sub-Nyquist MIMO radar with cognitive transmission, achieving substantial sampling reduction and demonstrating real-time operation.

Findings

87.5% reduction in combined spatial and spectral sampling

Effective signal recovery with thinned array configuration

Real-time experimental validation of the prototype

Abstract

We present the design and hardware implementation of a radar prototype that demonstrates the principle of a sub-Nyquist collocated multiple-input multiple-output (MIMO) radar. The setup allows sampling in both spatial and spectral domains at rates much lower than dictated by the Nyquist sampling theorem. Our prototype realizes an X-band MIMO radar that can be configured to have a maximum of 8 transmit and 10 receive antenna elements. We use frequency division multiplexing (FDM) to achieve the orthogonality of MIMO waveforms and apply the Xampling framework for signal recovery. The prototype also implements a cognitive transmission scheme where each transmit waveform is restricted to those pre-determined subbands of the full signal bandwidth that the receiver samples and processes. Real-time experiments show reasonable recovery performance while operating as a 4x5 thinned random array wherein the combined spatial and spectral sampling factor reduction is 87.5% of that of a filled 8x10 array.