Multirate subharmonic sampling

A new subharmonic sampling approach is introduced whereby the inphase and quadrature mixers are eliminated through the use of a multirate digital signal processing structure. This extends the concept of subharmonic sampling such that a variety of symbol rates can be accommodated. The system outputs can be processed directly or, if desired, easily converted to inphase and quadrature components for further processing by the remaining communications system. An example is given in which the digital outputs are directly utilized in a time tracking discriminator