Data timing schemes for software radio systems

Due to the great development of personal computers and networks, we have chosen general PCs interconnected by the Ethernet as the hardware platform of the software radio system*. Using wideband digitization, signal processing tasks are performed in user spaces of these PCs. However, there is a data timing problem in this scheme. High performance ADCs process samples under the control of their own clocks, which requires the incoming sample stream to be continuous and regularly spaced. But today's PCs lack an I/O system capable of delivering constant sample stream to the analog front-end. In this paper, several schemes are presented to solve this problem. Simulation results and performance evaluation are also presented.