Programmable IF architecture for multi-standard software defined radios

An improved intermediate frequency (IF) architecture for software defined radios is presented. This architecture is programmable, reconfigurable and suited to hardware implementation. The architecture is based on a computationally efficient method of extracting multiple channels belonging to two different communication standards, GSM and IS-95. The core of the system comprises of polyphase DFT filterbanks and very economical fractional rate-change filters. A flexible and efficient sample rate conversion method is also proposed that performs common rate changes using a shared hardware structure. Computational and hardware complexity comparisons are made based on results from a simulation test-bed developed for the proposed system.