Non-data-aided timing recovery algorithm for /spl pi//4-QPSK modulated signals

A new baseband clock recovery algorithm for /spl pi//4-QPSK modulated signals is presented. Conventional data-aided algorithm for /spl pi//4-QPSK modulated signals achieves good jitter performance, but suffers from slow initial acquisition and are prone to the potential error accumulation. Several non-data-aided timing recovery algorithms showing jitter performance approaching that of data-aided ones are proposed. Rayleigh fading and Gaussian noise are considered in the simulation. Simulation results show that the proposed non-data-aided algorithms satisfy the necessary requirements under Rayleigh fading.