Cognitive sub-Nyquist hardware prototype of a collocated MIMO radar

Abstract

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 4 × 5 thinned random array wherein the combined spatial and spectral sampling factor reduction is 87.5% of that of a filled 8 × 10 array.

TenDSuR: Tensor-Based 4D Sub-Nyquist Radar

“…Further, reduction in system resources enables the radar to share them among different applications. For instance, technologies like multi-function integrated radio-frequency (RF) aperture systems [4][5][6], spectral coexistence [7,8], cognitive radars [9,10] and reconfigurable arrays [11] provide multiple services such as surveillance, tracking, and communication using a single system.…”

Sub-Nyquist MIMO radar prototype with Doppler processing

“…More importantly, for each channel, a single low-rate ADC can subsample this narrow-band signal as long as the subbands are coset bands so that they do not alias after sampling [19]. Table I lists details technical characteristics of the prototype can be found in [10]. The system can be configured to operate in various array configurations or modes.…”

“…Our previous work [10] describes the design philosophy of the prototype. Briefly, we use the same hardware for each receive element and serially feed the signals of all 10 receivers to the same prototype.…”

“…Our very recent work [10] presents a hardware prototype of the SUMMeR system and demonstrates its feasibility via real-time experiments. This implementation follows the recommendations of [11] for signal orthogonality, array structure and reconstruction algorithms.…”

“…Additionally, we use cognitive transmission techniques [12], as in [10], wherein the transmit signal is limited to those selected subbands that a sub-Nyquist receiver samples and processes. In one of our previous works on single antenna radar systems [13], the sub-Nyquist radar hardware pre-filters a few randomly chosen, narrow subbands of the received signal spectrum before sampling them using low-rate analog-to-digital converters (ADCs).…”