Patent ID: 7965946

Claim:
A method for calibrating skew in a multichannel optical transport network (OTN) transmission device, the method comprising: accepting a pair of 2 n -phase shift keying (2 n PSK) modulated signals via Ix and Qx electrical signal paths, where n>1; accepting a pair of 2 p -PSK modulated signals via Iy and Qy electrical signal paths where p>1; correlating the Ix, Qx, Iy, and Qy signals to a predetermined preamble/header portion of an OTN frame; comparing a voltage V 1 on the Ix signal path with a voltage V 2 on the Qx signal path; generating a VO 12 voltage in response to the comparison; comparing a voltage V 3 on the Iy signal path with a voltage V 4 on the Qy signal path; generating a VO 34 voltage in response to the comparison; comparing a voltage on a signal path selected from a first group consisting of Ix and Qx with a voltage selected from a second group consisting of Iy and Qy; generating a first VOxy (VOxyA) voltage in response to the comparison; and, minimizing the generated VO voltages in response to adjusting time delay modules in the Ix, Qx, Iy, and Qy signals paths.