Downconversion on an AD Blackfin

Hi All,

I’m currently working on a SDR receiver for amateur radio astronomy use
my capstone class for my undergraduate engineering degree. Flexibily
“hackabilty” are two major considerations we have been putting into the
design. We are currently considering the following setup:

Antenna > RF Front End > LTC2206 - 16-Bit, 80Msps ADC > DSP or FPGA >
2.0 via Cypress FX2 > GNU Radio

This setup will allow us to capture up (theortically) 40MHz. Right now
biggest concern is in the downconversion on the reciever. We are
looking at
either using an FPGA or (preferably) a DSP to do the downconversion and
decimation. While I know it can be done in an FPGA, I was wondering if
anyone has any experience doing this in a DSP? Specifically i’m looking
the Blackfin lineup from Analog Devices.