Emerging technologies in software defined receivers

Transform Domain (TD) sampling is presented as an inexpensive and feasible solution for software defined receivers that operate on a very wide frequency spectrum. TD receivers expand the received signal over a basis set, and then operate on the basis coefficients. An analog computation of the basis coefficients efficiently parallelizes the signal for digital processing, relaxing the sampling requirements and enabling parallel digital processing at a much lower rate. Frequency Domain (FD) sampling, as a special case of transform-domain sampling, has been proposed to parallelize the sampling process in wideband receivers. The proposed receiver makes use of a windowed integrator to perform charge sampling, which provides inherent anti-aliasing. More complex decimation filters with stronger attenuation of the unwanted channels are easily obtained from the simple integrator and can be exploited in designing a multi-standard receiver. The flexibility and scalability of TD receivers allow for the design of software radios that can operate on a large range of narrowband and wideband communications standards. A "dreamed software-defined-radio" TD receiver design example is provided which is capable of processing GSM, Bluetooth, IEEE802.11b/g, WiMax and UWB in a single reconfigurable frontend.