- The paper proposes a multibeam framework using fixed communication and scanning sensing subbeams generated from a single steerable analog antenna array to overcome conflicting beamforming requirements.
- Key contributions include a system architecture allowing continuous receiver operation, low-complexity beamforming methods, and sensing parameter estimation algorithms leveraging the multibeam structure.
- Simulations validate that the multibeam approach effectively integrates sensing into TDD/OFDM communication systems, improving joint function performance and reducing hardware/cost for applications like UAVs and smart cars.
Multibeam for Joint Communication and Sensing Using Steerable Analog Antenna Arrays
The paper "Multibeam for Joint Communication and Sensing Using Steerable Analog Antenna Arrays" authored by Zhang et al. introduces an innovative approach to integrate communication and sensing functionalities using multibeam technology in systems utilizing steerable analog antenna arrays. This work is particularly relevant for technologies like unmanned aerial vehicles (UAVs) and smart cars, where size, cost, and spectrum efficiency are critical factors.
Overview and Contributions
The authors address the challenges posed by differing beamforming requirements for communication and radar sensing. Traditional systems employ separate hardware and signal processing modules for these two functions, creating inefficiencies. Beamforming has been separately optimized for communication and radar sensing, but the integration into a joint system presents complications, such as the need for stable communication beams and the simultaneous necessity for time-varying sensing beams.
The core contribution of this paper is in proposing a multibeam framework wherein two subbeams are employed: a fixed subbeam for communication and a dynamically adjustable scanning subbeam for sensing. This represents a significant departure from conventional single-beam Joint Communication and Sensing (JCAS) schemes. The multibeam approach allows these beams to be generated from a single transmitting array, optimizing the use of hardware resources.
Key contributions of this framework include:
- System Architecture and Protocols: The authors propose a system design that utilizes two spatially separated steerable antenna arrays to perform communication and sensing. This allows continuous operation of the receiver by mitigating signal leakage from the transmitter.
- Beamforming Design: The flexible and low-complexity methods are proposed for multibeam design to adapt to varying communication and sensing requirements. The beamforming solution builds on the generalized Least Squares approach to generate desired beam shapes while maintaining power constraints.
- Sensing Algorithms: Sensing parameter estimation methods are developed using both conventional digital Fourier transform and 1D compressive sensing techniques. These approaches leverage the multibeam structure and are effective under constraints typical in real-time deployment on platforms like UAVs.
Simulation Results
The authors validate their approach through extensive simulations. Results demonstrate that their framework can effectively integrate sensing functionalities into typical time-division duplex (TDD) packet-based communication systems with multicarrier modulation, particularly orthogonal frequency-division multiplexing (OFDM). The effectiveness of beamforming design methods and sensing algorithms is corroborated by these simulations, showing that the proposed multibeam structure improves the ability to jointly fulfill communication and sensing requirements.
Implications and Future Directions
This paper adds significant value to the development of JCAS systems, especially in automotive and UAV applications, by providing a method to reduce the hardware footprint, cost, and spectrum usage while enhancing system capabilities through joint functions. The extension of multibeam technology into these domains could catalyze further refinements in algorithms that accommodate high-dimensional and off-grid sensing models. Future research may focus on tackling issues related to quantization in beamforming vector generation, optimizing subbeam combination, and resolving the angle of arrival (AoA) and angle of departure (AoD) in more complex scenarios.
By resolving conflicting design requirements inherent to communication and sensing functions through the use of multibeams, this work sets a precedent in the development of compact, efficient, and cost-effective JCAS systems. It stands to have a considerable impact as emerging platforms increasingly demand seamless integration of both functionalities.