Abstract: For the received signals were sampled at a fixed rate that is asynchronous with the data clock in software radio, we implement symbol synchronization during the process of decimation which replace general methods by using an interpolator in the baseband stage, and Maximum Likelihood(ML) timing synchronization techniques can be incorporated into the filters polyphase decomposition in a natural way. In order to match the timing delay of received signals to the data timing delay, the timing delay structure was adjusted by utilizing the timing error. Cascaded Integrator Comb (CIC) filters and HalfBand Filters (HDF) served as decimation filters that reduce the system complexity and computational burden to a certain extent. The numerical simulation results show that the value of timing delay structure will be converged to a constant with small fluctuation when the received signals timing delay matches the data timing delay, and the output from the last stage of FIR is the optimal sampled signals.