Spatial Σ-Δ Signal Acquisition for Wideband Beamforming Arrays

Abstract:
We consider spatial and spatio-temporal σ-δ modulation structures for wideband signal acquisition with dense sensor arrays. Using closely arranged sensors, the array oversamples the signal in space and applies coarse quantization to each sensor output. A σ-δ structure propagates quantization noise between sensors to shape the noise in space, just as a time-domain σ-δ converter shapes noise in frequency. The spatially shaped noise is then filtered by a delayand-sum beamformer. In this work, we also introduce higherorder σ-δ structures and hybrid space-time architectures that can achieve greater noise shaping in both space and time. The coarsely quantized σ-δ structure can be used to build high-resolution arrays with lower power and complexity.