Study, Simulation and Implementation of Coarse and Fine Delay for Satellite Link Enulation

Aim of the work is to implement coarse and fine delay to be added in a signal. This will be utilized in development of Channel emulator, Calibration of Phased array element for wideband signals, for an Echo canceller kind of Applications. The Coarse delay will be consisting of integer delay with respect to sampling frequency whereas Fine delay will be consisting of fractional delay with respect to sampling frequency. Various algorithms such as the brute forced Fourier method and using sinc function have been studied for coarse delay. Due to less complexity, sinc function method is used in our project. For fractional delay, various Interpolations based method, Hybrid analog to digital converter, least square integral error method and Lagrange Interpolation based method is studied and simulated. Trade off analysis is carried out for deciding algorithm for fractional delay considering implementation complexity, feasibility to implement on hardware and accuracy in terms of Mean square error and real time implementation. Proposed module will emulate time varying delay for testing satellite link performance and it will be part of satellite link emulator, and Phased array antenna which will correct differential group delay between elements which is consisting of integer and fractional delay. It will also compensate the delay between echo canceller output and the receiver input for echo cancellation.