Reconfigurable Architecture for Spatial Sensing in Wideband Radio Front-End

Mansi Gupta, Somya Sharma, Himani Joshi, Sumit Jagdish Darak

Abstract: The deployment of cellular spectrum in licensed, shared, and unlicensed spectrum demands wideband sensing over non-contiguous sub-6 GHz spectrum. To improve the spectrum and energy efficiency, beamforming and massive multi-antenna systems are being explored, demanding spatial sensing, i.e., blind identification of vacant frequency bands and direction-of-arrival (DoA) of the occupied bands. We propose a reconfigurable architecture to perform spatial sensing of multi-band spectrum digitized via wideband radio front-end comprising the sparse antenna array (SAA) and Sub-Nyquist Sampling (SNS). The proposed architecture comprises SAA pre-processing and algorithms to perform spatial sensing directly on SNS samples. The proposed architecture is realized on Zynq System-on-chip (ZSoC), consisting of the ARM processor and Field Programmable Gate Array (FPGA), via hardware-software co-design (HSCD). Dynamic partial reconfiguration (DPR) allows on-the-fly switching between algorithms depending on the number of active signals in the sensed spectrum. The functionality, resource utilization, and execution time of the proposed architecture are analyzed for various HSCD configurations, word-length, number of digitized samples, signal-to-noise ratio (SNR), and antenna array (sparse/non-sparse).