A Proposal of an Efficient Timing Recovery Algorithm for 4-ary Elliptical Phase Shift Keying

M-ary elliptical phase shift keying (M-EPSK, M=2,4,8) have been proposed in our previous works. Evaluation results show that M-EPSK can achieve advantage over MPSK on noise performance. In particular, M-EPSK can adoptively make trade-offs between bandwidth efficiency and power efficiency by varying eccentricities. However, the analysis in previous works also shows that the achieved performance of M-EPSK is vulnerable to synchronization errors. To realize efficient signal detection and to provide simplicity for receiver 4-EPSK (M- EPSK of M=4), in this paper, we propose an efficient timing recovery algorithm for 4-EPSK by employing envelope characteristics of elliptical signals.