A novel algorithm for blind joint equalization and Carrier Phase Estimation in 16-QAM coherent optical communication

We propose a new radial directed joint equalization technique for blind adaptive equalization and Carrier Phase Estimation of Quadrature Amplitude Modulation (QAM) in coherent optical fiber communication. By taking the advantages of radial directed constant modulus algorithm (RD-CMA) and multimodulus algorithm (MMA), we introduced a new equalization technique can be call Radial Directed Multi Modulus Algorithm (RD-MMA) which can compensate the fiber dispersions and phase fluctuations hence the laser phase noise. By comparing with the traditional multi modulus algorithm (MMA) we found MMA can compensate up to 30 KHz Laser phase noise where as our algorithm can compensates 100 KHz for the same power penalty. for less than 100 KHz laser our algorithm performs much better with less amount of OSNR penalty.