A low computational complexity and high accuracy DOA estimation method in the hybrid analog-digital system with interleaved subarrays

The large-scale, partially connected phase-shifter Hybrid Analog-Digital System (HADS) has attracted significant attention due to its low hardware complexity, high reconfigurability, and robustness to failures. Direction-of-Arrival (DOA) estimation presents a critical challenge in HADS, as it directly impacts the Signal-to- Noise Ratio (SNR) and throughput. Existing DOA estimation methods in HADS, however, are hindered by high complexity, the need for sign corrections, and ambiguity. This paper proposes an accurate and unambiguous DOA estimation method for HADS with interleaved subarrays (HADSIS) under specific phase shift conditions. The method utilizes cross-correlation between signals received by adjacent subarrays to directly estimate the DOA through coherent accumulation. This approach simplifies DOA estimation and eliminates ambiguity, thereby significantly enhancing estimation efficiency. Furthermore, the sign of the cross-correlation is uniquely determined by the parity of the number of subarrays, eliminating the need for further sign corrections during signal accumulation. Finally, simulation experiments are conducted to validate the performance of the proposed method. Our approach enhances the SNR of the cross-correlation results, thereby ensuring more accurate DOA estimation. Its key features include low computational complexity and high accuracy.