IEEE 802.11ad-based Radar: An Approach to Joint Vehicular Communication-Radar System (1702.05833v1)

Abstract: Millimeter-wave (mmWave) radar is widely used in vehicles for applications such as adaptive cruise control and collision avoidance. In this paper, we propose an IEEE 802.11ad-based radar for long-range radar (LRR) applications at the 60 GHz unlicensed band. We exploit the preamble of a single-carrier (SC) physical layer (PHY) frame, which consists of Golay complementary sequences with good correlation properties, as a radar waveform. This system enables a joint waveform for automotive radar and a potential mmWave vehicular communication system based on IEEE 802.11ad, allowing hardware reuse. To formulate an integrated framework of vehicle-to-vehicle (V2V) communication and LRR based on a mmWave consumer wireless local area network (WLAN) standard, we make typical assumptions for LRR applications and incorporate the full duplex radar assumption due to the possibility of sufficient isolation and self-interference cancellation. We develop single- and multi-frame radar receiver algorithms for target detection as well as range and velocity estimation within a coherent processing interval. Our proposed radar processing algorithms leverage channel estimation and time-frequency synchronization techniques used in a conventional IEEE 802.11ad receiver with minimal modifications. Analysis and simulations show that in a single target scenario, a Gbps data rate is achieved simultaneously with cm-level range accuracy and cm/s-level velocity accuracy. The target vehicle is detected with a high probability of detection ($>$99.9$\%$) at a low false alarm of 10$^{-6}$ for an equivalent isotropically radiated power (EIRP) of 43 dBm up to a vehicle separation distance of 200 m.

• The paper introduces a joint vehicular communication and radar system by repurposing the IEEE 802.11ad preamble with Golay sequences for hardware reuse.
• The paper develops novel single- and multi-frame radar algorithms that achieve cm-level range and cm/s-level velocity accuracy with over 99.9% detection probability.
• The paper validates the approach through CRLB analysis and simulations, demonstrating Gbps communication speeds alongside precise vehicular sensing.

Overview of IEEE 802.11ad-based Radar for Vehicular Communication

The paper presents an approach to integrating vehicular radar with communication systems using the IEEE 802.11ad standard, focusing on millimeter-wave (mmWave) radars operating at 60 GHz. The authors propose a method that employs the IEEE 802.11ad preamble as a radar waveform, facilitating a joint vehicular communication-radar system that enables hardware reuse.

Key Contributions

1. System Model: The research introduces a comprehensive system model for jointly implementing vehicle-to-vehicle (V2V) communication and long-range radar (LRR) functionalities. This is achieved by leveraging the IEEE 802.11ad single-carrier (SC) physical layer (PHY) frame, which includes Golay complementary sequences suitable for radar applications due to their favorable correlation properties.
2. Radar Algorithms: Novel algorithms for single- and multi-frame radar reception are developed for target detection, range estimation, and velocity calculation. These algorithms build upon existing channel estimation and synchronization techniques used in IEEE 802.11ad communications, thereby requiring minimal modifications to existing systems.
3. Performance Evaluation: The paper provides both theoretical and simulated analysis demonstrating that the system can achieve Gbps data rates along with cm-level range and cm/s-level velocity accuracy. In a single-target scenario, the probability of detection exceeds 99.9% with a false alarm rate of 10$^{-6}$.
4. Numerical and Analytical Insights: Through the Cramer-Rao lower bound (CRLB) analysis, the authors validate their algorithms' performance, highlighting close alignment with theoretical bounds for range and velocity estimation.

Implications and Future Directions

The integration of mmWave communication and radar systems as proposed could significantly enhance vehicular safety systems by allowing simultaneous high-speed data transfer and environment sensing. This has implications not only in improving existing automotive functions like adaptive cruise control but also in advancing fully automated driving systems.

The paper suggests that such a joint system could increase the adoption and penetration of mmWave communication technologies in vehicles, potentially reducing latency and enhancing security through the fusion of communication and radar data.

Speculating on future research, questions remain about optimizing these systems under varying vehicular and environmental conditions, such as high-speed mobility, non-line-of-sight scenarios, or multi-path interference. Further investigation into scalability and integration with other communication standards, such as 5G, could provide additional enhancements and flexibility.

Conclusion

This research offers a detailed and promising methodology for creating a joint communication-radar system using existing IEEE 802.11ad standards, providing a basis for both immediate application and future exploration in automotive technology. The approach's potential to streamline vehicular communication infrastructure while enhancing radar capabilities marks a notable contribution to the field of intelligent transportation systems.