Quantization-Aware Hybrid Anti-Interference Receiver for Partially Connected Arrays with Low-Resolution ADCs

Partially connected hybrid analog-digital beamforming architectures substantially reduce the hardware cost and power dissipation of massive antenna arrays by routing multiple antenna elements to a single radio-frequency (RF) chain. In contested or dense electromagnetic environments, however, strong directional interference entering low-resolution analog-to-digital converters (ADCs) increases signal-dependent quantization distortion and can exceed the converter range if gain control is inadequate. To overcome this fundamental bottleneck, this paper develops a quantization-aware hybrid anti-interference receiver for partially connected architectures constrained by finite-resolution phase shifters and low-bit ADCs. The proposed receiver operates in three coordinated stages. In the spatial sensing stage, the receiver sequentially applies multiple pseudo-random analog combining configurations to collect compressed spatial observations, and reconstructs the angular power spectrum of unknown interference sources via an additive quantization noise model (AQNM)-corrected nonnegative sparse covariance fitting problem solved by the fast iterative shrinkage-thresholding algorithm (FISTA). In the analog beamforming stage, using the reconstructed interference-plus-noise covariance, subarray analog combiners are optimized directly on the complex constant-modulus manifold via Riemannian gradient descent and mapped to discrete phase states, forming analog spatial nulls to reduce interference before quantization. In the digital combining stage, a diagonally loaded robust minimum variance distortionless response (R-MVDR) combiner is formulated directly on the quantized RF domain to suppress residual interference and tolerate covariance estimation errors. Comprehensive simulations demonstrate that the proposed receiver improves output signal-to-interference-plus-noise ratio (SINR) relative to the evaluated hybrid baselines, maintaining substantial performance advantages over conventional hybrid beamforming baselines across diverse interference powers, ADC bit depths (3–8 bits), coarse phase quantization (3–8 bits), reduced RF chain counts, and limited snapshot budgets.