Patent ID: 7962043

Claim:
A method for controlling time delay 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; comparing a voltage V 1 on the Ix signal path with a voltage V 2 on the Qx signal path; generating a VOx voltage in response to the comparison; minimizing VOx by adjusting time delay modules in the Ix and Qx signals paths; comparing a voltage V 3 on the Iy signal path with a voltage V 4 on the Qy signal path; generating a VOy voltage in response to the comparison; minimizing VOy by adjusting time delay modules in the Iy and Qy signals paths; subsequent to minimizing VOx and VOy, comparing the sum of V 1 and V 2 (V 12 ) with the sum of V 3 and V 4 (V 34 ); generating a VOxy voltage in response to comparing V 12 to V 34 ; and, minimizing VOxy by adjusting the time delay between the 2 n PSK and 2 p PSK signals.