Bio-Inspired Hybrid Filter Bank for Software-Defined Radio Receivers
; Magalhães, JPM
; Gomez-Garcia, RGG
IEEE Transactions on Microwave Theory and Techniques Vol. 61, Nº 4, pp. 1455 - 1466, April, 2013.
ISSN (print): 0018-9480
Journal Impact Factor: 2,711 (in 2008)
Digital Object Identifier: 10.1109/TMTT.2013.2246184
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For an efficient exploitation of the RF spectrum,
very sophisticated analog-to-digital front-ends for modern cog- nitive-/software-defined radios featuring high sampling rate and dynamic range are required to properly handle broadband fre- quency-sparse signals. For this purpose, a receiver solution based on a mixed-analog/digital-domain channelizer can be advanta- geous, with added benefits regarding system reconfigurability and parallelization of multiband signal processing. Here, a novel receiver architecture using this approach for the commented application is described, with a special focus on the IF hybrid filter bank as its core element. The analog part of the hybrid filter bank is a 50–100-MHz eight-channel analog multiplexer inspired in the human hearing system. The associated digital block can be co-synthesized as a discrete-time filter bank to invert the action of the IF analog channelizer. As a benefit, hardware imperfections inherent to the analog circuitry can be easily counteracted at the digital level. Furthermore, such a channelization enables low-cost analog-to-digital converters to be utilized for the sampling of the signal sub-bands to be later digitally processed for the overall signal reconstruction. For validation, measured and simulated results of a proof-of-concept prototype for the analog channelizer are shown. Besides, the inversion of the measured transfer func- tions of thismultiplexing device bymeans of the application of the co-designed digital filter bank is demonstrated. An experiment is also carried out showing the reconstruction of a band-limited noise signal with the developed hybrid filter bank.