Patent ID: 8655191

Claim:
A method in a receiver for recovering clock timing of a polarization division multiplexed (PDM) signal having two linear polarization states, each having an in-phase and quadrature-phase component, wherein complex signals X and Y represent sampled in-phase and quadrature-phase components for each orthogonal linear polarization state of the PDM signal, comprising the steps of: processing each of the complex signals X and Y using at least one or more reference frequencies associated with a spectrum of the sampled PDM signal to obtain co-polarization and cross-polarization terms for each orthogonal linear polarization state of the one or more reference frequencies; and determining a phase of a determinant of a two-by-two matrix, from said terms, the two-by-two matrix having the co-polarization and cross-polarization terms as elements therein, said phase value being indicative of clock timing offset of the PDM signal.