Timing recovery techniques for digital cellular radio with π/4-DQPSK modulation

A class of timing recovery techniques for π/4-differential quadrature phase shift keying (DQPSK) signals in digital cellular systems is studied. The timing recovery techniques are composed of a zero-memory nonlinear device and a narrowband bandpass filter or a phase-locked loop which is tuned to the clock rate. These timing recovery schemes are evaluated at IF-band in Rayleigh fading channels. The jitter performances over static and dynamic channels were simulated and are compared. From the simulation results, it is found that the class of timing recovery techniques is insensitive to the fading effect