A digital timing recovery scheme for TDMA digital mobile radio

In digital mobile communications, the received signal is not only interfered by the additive white Gaussian noise (AWGN), but also affected by the multipath fading effect. In this situation, regenerating the timing information from the faded signal is difficult. In TDMA digital cellular radio with π/4-DQPSK modulation (e.g. IS-54 system), a fast converging and stable timing recovery scheme is required because the synchronization sequence is usually very short. In this paper, we present a new nonlinear digital timing recovery scheme composed of Gardner´s timing error detector, digital loop filter and digital controlled oscillator (DCO)