Patent ID: 8908809
Filing Date: 2014-12-09
Classification: H04B,H04L

Abstract:
1. A method of carrier phase error removal associated with an optical high-order communication signal, capable of achieving increased laser line-width tolerance, the method comprising: estimating and removing a first phase angle associated with an information symbol using coarse phase recovery to provide a first coarse phase recovered signal, the information symbol being associated with a digital signal, the digital signal being an optical high-order communication signal; estimating and removing a carrier frequency offset by using the estimated first phase angle to provide a carrier frequency offset removed signal, the carrier frequency offset being associated with a current information symbol; removing carrier phase error associated with the carrier frequency offset; and estimating and removing a second phase angle associated with the optical high-order communication signal modulated with the current information symbol to provide a second refined phase recovered signal, the second phase angle being removed using the first coarse phase recovered signal and the carrier frequency offset removed signal by performing a maximum likelihood carrier phase estimation.