Waveform Design for Joint Millimeter Wave Communication and Radar
Surface transportation safety can be enhanced by the use of wireless technologies, mainly automotive radar and vehicle-to-vehicle (V2V) communication. Automotive radar provides a high-resolution low-latency approach for a continuous automatic detection and ranging of both communication-enabled and non-communication-enabled transportation users. V2V systems rely on the collaborative communication between vehicles to achieve a real-time cooperative detection and ranging. They can operate beyond the line-of-sight constraints of radar solutions. Combining both these wireless technologies would provide a hybrid detection and ranging application that would benefit from mutual sharing of information between radar and communication using the same frequency band and hardware resources. Furthermore, using the mmWave band will provide a high data rate for communication and better accuracy & resolution for radar operation. This will enable automotive safety applications to simultaneously achieve ultra-low latency and high range of operation, with advantages of reduced cost, size, better performance and efficient spectrum usage for the vehicles of tomorrow. In the past half-decade, a number of joint communication-radar approaches have been considered, which exploits the existing radar/communication waveforms that are usually ad-hoc designed and is not completely integrated as they rely on time, frequency or code division ideas.
Leveraging the use of a mmWave consumer wireless local area network (WLAN) standard, WNCG graduate student Preeti Kumari, WNCG post doctoral fellow Dr. Junil Choi, Universidade de Vigo Professor Nuria González Prelcic, and WNCG Professor Robert Heath developed a combined vehicular communication-radar waveform, referred to as IEEE 802.11ad V2X-Radar. In particular, they have exploited the use of the special structure (repeated Golay complementary sequences) of the single carrier preamble in IEEE 802.11ad to develop a joint framework of long range automotive radar (LRR) and vehicle-to-vehicle communication (V2V) at 60 GHz. This framework leverages the signal processing algorithms used in the typical WLAN receiver for carrier frequency offset estimation and channel estimation for radar parameter estimation. The theoretical analyses and numerical simulations show promising results; cm-level range and cm/s-level velocity accuracy are achieved with high probability of detection simultaneously with Gbps communication data rate. To further improve the radar performance, Kumari, WNCG post doctoral fellow Dr. Duy H. N. Nguyen and Prof. Heath are designing a time-domain duplex (TDD) joint waveform, which will embed radar waveform in the IEEE 802.11ad frame.
Part of this work was presented at 82nd IEEE Vehicular Technology Conference, September, 2015. A full journal version will be submitted to IEEE Transactions on Vehicular Technology.
This research was partially supported by the U.S. Department of Transportation through the Data-Supported Transportation Operations and Planning (D-STOP) Tier 1 University Transportation Center, by the Texas Department of Transportation under Project 0-6877 entitled “Communications and Radar-Supported Transportation Operations and Planning (CAR-STOP)” and by a gift from National Instruments.