Method of joint frame synchronization and data-aided channel estimation for 100-Gb/s polarization-division multiplexing–single carrier frequency domain equalization coherent optical transmission systems

To improve the performance of channel estimation (CE), a method of joint frame synchronization and data-aided CE using less training overhead is proposed. A 100-Gb/s polarization-division multiplexing coherent transmission system with quaternary phase-shift keying based on the proposed method is demonstrated by simulation. The simulation results show that the proposed method could achieve accurate timing offset and CE in the presence of strong amplified spontaneous emission noise.