Energy-efficient Analog Processing Architecture for Direction of Arrival with Microphone Array

Direction of arrival (DOA) is a critical component in the conventional smart acoustic system for navigation, noise canceling hearing aids and so on. However, conventional DOA has encountered power consumption and processing speed bottlenecks dominated by analog-to-digital converter (ADC) and fast fourier transform (FFT). Especially in the always-on applications, the power-hungry ADC and time-consuming FFT take up most of the system's computation cost. We propose a novel processing architecture with analog-domain processing for DOA. The whole processing procedure of DOA is implemented in the analog domain without ADC and frequency-domain transformation. In order to verify the performance of the architecture, we simulate a generic DOA algorithm. Under the CMOS 0.18µm process, the results show the 94.5% reduction in power consumption and 4724× improvement in processing speed compared to conventional digital realization. We simulate the simple task with the direction accuracy of 80.74%, which can be extended to a more complex scenario.