A Reconfigurable Digital Beamformer Implemented on a Field-Programmable Gate Array for Real-Time and Resource-Efficient Direction-of-Arrival Estimation

A medium- or large-scale receiving antenna array using digital beamforming can achieve high-resolution direction-of-arrival (DOA) estimation at the receiver. However, it typically suffers from high cost and complexity. This paper proposes an efficient reconfigurable digital beamformer that can achieve real-time angle estimation with high accuracy while making effective use of hardware resources. The digital beamformer operates in two modes: beamforming mode and angle estimation mode. In the angle estimation mode, the phase shift steps required for beam scanning can be flexibly adjusted according to the desired angular resolution. By dynamically switching operational modes and fine-tuning the granularity of processing tasks, this architecture maximizes the efficient use of Field-Programmable Gate Array (FPGA) resources, ensuring optimal performance and flexibility in real-time signal processing applications. Simulation results show that with an input signal-to-noise ratio of 10 dB, the beamformer can complete DOA estimation with an error of less than 1° within microsecond-level delay.