Low-SWaP Spectrum Sensing across 32 GHz Bandwidth at D-Band using Maximally-Decimated Uniform Approximate DFT Polyphase FIR Filterbanks on Altera Stratix-10 AX Chiplets
Conference
Nilan, M, Gayanath, B, Karunanayake, K et al. (2025). Low-SWaP Spectrum Sensing across 32 GHz Bandwidth at D-Band using Maximally-Decimated Uniform Approximate DFT Polyphase FIR Filterbanks on Altera Stratix-10 AX Chiplets
. 00 251-256. 10.1109/MILCOM64451.2025.11310029
Nilan, M, Gayanath, B, Karunanayake, K et al. (2025). Low-SWaP Spectrum Sensing across 32 GHz Bandwidth at D-Band using Maximally-Decimated Uniform Approximate DFT Polyphase FIR Filterbanks on Altera Stratix-10 AX Chiplets
. 00 251-256. 10.1109/MILCOM64451.2025.11310029
The increasing use of mm-waves and sub-THz bands, especially the 100-300 GHz range for a variety of wireless applications in the battlefield, opens up new challenges for sensors and systems. In this work, we demonstrate spectral channelization in the D-band across a 32 GHz bandwidth at a spectral resolution of 1 GHz with a sample rate 64 GS/s. A low-complexity polyphase filterbank that replaces fast Fourier transform (FFT) blocks that require O(N logN) multiplications with an approximate discrete Fourier transform (DFT) requiring zero multiplication operations is used for channelization. An analysis filterbank of order 32 is used for box-car responses across each subband, with a total interference suppression better than 44 dB. Spectrum occupancy is sensed using a multiplierless energy detection algorithm; an error correction technique is proposed and demonstrated experimentally to show how the approximate discrete Fourier transform (ADFT) errors can be largely removed for sensing applications. A testbed consisting of a D-band receiver from Virginia Diodes and a digital mixed-signal field programmable gate array (FPGA) platform from Altera with integrated analog-to-digital converters (ADCs) operating at 64 GS/s over 128 parallel digital phases are used for verification of the algorithms.
