A system and method are provided for calibrating skew in a multichannel optical transport network (OTN) transmission device. The method accepts a pair of 2n-phase shift keying (2nPSK) modulated signals via Ix and Qx electrical signal paths, where n>1. Likewise, a pair of 2p-PSK modulated signals are accepted via Iy and Qy electrical signal paths where p>1. The Ix, Qx, Iy, and Qy signals are correlated to a preamble/header portion of an OTN frame. A voltage on the Ix signal path is compared with Qx, and VO12 voltage is generated. A voltage on the Iy signal path is compared with Qy, and VO34 is generated. One of the Ix or Qx voltages is compared with one of Iy or Qy voltages to generate VOxy. Then, the VO voltages are minimized in response to adjusting time delay modules in the Ix, Qx, Iy, and Qy signals paths.