Order-of-magnitude accuracy improvements for self-driving cars and other applications
Vehicular RADARs have high device cost, since they exploit large spectrum resources at millimeter-wave frequencies (24 GHz and 77 GHz) with tightly-coupled analog circuits and advanced antenna configurations on expensive process technology to overcome link budget shortfalls. Current RADARs are also spectrally inefficient. In the standard RADAR processing architecture, for example with frequency-modulated continuous-wave (FMCW) RADAR, the resolution is limited by the distance between received digital samples, which means that the spectrum bandwidth must be 150 MHz for meter-level accuracy (a common requirement for vehicular RADAR). Current RADAR also has no multiple access capability and/or smart coexistence, which are fundamental to communication systems.
Researchers at The University of Texas at Austin have discovered a new signal processing framework and associated system configuration for RADAR that exploits available IEEE 802.11 devices. This invention enables wireless communication devices to operate as radio detection and ranging (RADAR) devices with high-resolution performance. Using off-the-shelf, commercially available wireless devices—e.g., IEEE 802.11a/b/g/n devices—standard receiver processing computes something called the channel impulse response, which profiles the way electromagnetic waves travel between the transmitter and receiver. The invention exploits this impulse response, available in every wireless communication device receiver, to product target estimates.
This innovation enables up to one order of magnitude cost reduction in vehicular RADAR processing devices by enabling vehicular RADAR processing using off-the-shelf IEEE 802.11 devices at microwave frequencies, without modification to silicon. Preliminary results have also shown that wireless communication devices with SSTE processing can offer 7.5× higher accuracy in target range estimates or 87% less required spectrum bandwidth when compared to standard RADAR waveforms with standard RADAR processing. Our system enables secure RADAR with coexistence as provided by IEEE 802.11 networks. This technology has been tested in the real world, with the results described in the published journal article found here.