PILOT-ASSISTED DATA TRANSMISSION IN A COHERENT OPTICAL-COMMUNICATION SYSTEM

摘要

In one embodiment, an optical transmission system transmits data using a format according to which a data frame has two or more pilot-symbol blocks, each having a guard interval, and two or more payload-symbol blocks that are concatenated without a guard interval between them. The use of guard intervals in the pilot-symbol blocks helps the synchronization and channel-estimation procedures performed at a receiver of the optical transmission system to be robust in the presence of certain transmission impairments. The absence of guard intervals in the payload-symbol blocks helps to minimize the transmission overhead and thus achieve relatively high payload-data throughput. Pilot-symbol blocks have a structure that enables the receiver to determine channel-response characteristics for each data frame and then apply appropriate channel-response-compensation procedures to signals corresponding to the payload-symbol blocks of the frame to recover, with a relatively low bit-error rate, the data encoded in those signals.