FLEXIBLE CHANNEL EXTRACTOR FOR WIDEBAND SYSTEMS BASED ON POLYPHASE FILTER BANK

摘要

Some applications as Software Defined Radio (SDR) and Cognitive Radio require the analysis of wideband signals and/or the processing of multiple channels that can be located anywhere in the available band. These requirements can be satisfied using hardware platforms based on fast Analog to Digital Converters (ADCs) and reconfigurable hardware, such as FPGAs. Unfortunately, while modern ADCs allow the acquisition of wideband signals at high sampling rates (many Gsps), FPGAs are not able to work with very high rates. In this work, authors propose a solution to overcome this problem in a class of applications. The solution is based on the coupling of a Time-Interleaved ADC (TI-ADC) with an FPGA front-end, exploiting the properties of a perfect reconstruction polyphase filter bank. The proposed system is able to select and process channels located anywhere in the input wide band and to re-aggregate two or more of them obtaining a new channel with variable width.