Spectral Co-Design Prototype For Automotive Mimo Radar Mimo Communications System

Futuristic smart vehicle technologies are envisioned to operate a large number of sensors to provide greater in-vehicle and inter-vehicle activities, safety, efficiency, and connectivity. In this context, integrating the communications and radar sensors is of critical importance to minimize the hardware footprint and share the spectrum. We present a spectrum-sharing prototype that demonstrates the common transmitter-receiver design (co-design), of Multiple-Input Multiple-Output (MIMO) Radar and vehicle-to-vehicle (V2V) MIMO communications (MRMC). Both systems share the same antenna and operate via multiplexing on a pulse-to-pulse basis within a coherent processing interval. The co-designed radar embeds the communications symbols in a novel, optimized, discrete-phase sequence, which is robust to the quantization errors introduced by digital-to-analog converters. The MRMC receiver, which operates in real-time, is capable of separating the semi-orthogonal transmit signals and decoding the communications constellation. The prototype is developed using General Purpose Processor (GPP) based Software Defined Radios (SDRs): NI USRP 2943R (1.2GHz - 6GHz) and Ettus USRP B210 (70 MHz – 6 GHz). Unlike our MRMC coexistence prototype, the co-design demo incorporates a joint MIMO radar/ communication transmitter whose baseband processing is performed inside GPP using Labview NXG 3.1. The prototype offers flexibility to choose from a variety of radar waveforms, including optimized discrete-phase as other well-known sequences (e.g. Binary, frank, Golomb), and frequency modulation along with on-the-fly reconfigurable multiplexing operation. Communication symbols for multiplexing are drawn from IEEE-802.11p, (10 MHz, being used for V2V communications). The radar tasks include target range, Doppler, angle of arrival estimation while the communication receiver decodes IEEE-802.11p MAC frames. We presented our first MRMC co-design prototype at SPAWC 2019 without the full MIMO capability, especially direction-of-arrival (DoA) recovery. In the current submission, we have incorporated advanced MIMO functionality in radar and communications set-ups, such as a new co-designed waveform for an entire coherent processing interval of the radar, space-time processing, and DoA estimation. Our MRMC co-design prototype effectively demonstrates a joint waveform transmission and recovery in multi-functional, shared multiple antenna systems.