Blackfin DSP based WorldSpace satellite radio

WorldSpace satellites broadcast multi channel digital audio, images and data over Asia, Africa and some parts of Europe. Existing WorldSpace radios use ASIC based chip sets that don´t support easy system upgrades. In this context, ‘DSP based soft Radio’ has tremendous advantage. A few years ago, it was not possible to have a cost effective DSP solution. However the last couple of years have seen the emergence of several low cost and high speed DSPs because of which it is now feasible to have a DSP based satellite radio for the consumer market. An important technical challenge that one faces in coming up with complete DSP based radio is the design of computation intensive physical layer as that demands conflicting requirements: lesser number of computations and good receiver performance in terms of noise performance. A reference model (prototype) has been developed using a single Blackfin DSP processor performing all digital processing tasks such as base band processing, channel decoding and source decoding for a WorldSpace satellite receiver. This reference model demonstrates that it is possible to make DSP based radios without any support from ASICS or FPGAs to achieve reduction in cost, increased performance and flexibility by using the latest fixed point DSPs such as Blackfin processors. This is a very encouraging fact because the same hardware can work for different types of radios, leading to an attractive proposition of easily reconfigurable radios either by changing the flash memory or by down-loading the software via internet.