Digital signal processing based methods and systems for receiving electrical andor optical data signals include electrical receivers, optical receivers, parallel receivers, multi-channel receivers, timing recovery schemes, and, without limitation, equalization schemes. First, authorization is obtained from a plurality of payor entities which allows a service provider to make payments, on behalf of the plurality of payor entities, to a plurality of payee entities. The second grating is disposed in a rotated state while being kept in parallel with the first grating. Finally a projection stage is provided for projecting the image, typically on a projection screen.