A multi-channel (e.g. WDM) receiver, in which l PMD compensators are time-shared by n (n>1) communication channels, where 1.ltoreq.l.ltoreq.n-1. The receiver implements PMD monitoring to identify channels exhibiting relatively high amounts of PMD. Some or all of the identified channels are then subjected, before decoding, to PMD-reduction processing, while the remaining channels are decoded without such processing. Channel allocation for the processing may be changed dynamically depending on the current amounts of PMD exhibited by various channels. Due to efficient utilization of PMD compensators, multi-channel receivers of the invention are capable of performance comparable to that of the corresponding fully compensated (i.e., having a dedicated PMD compensator for each channel) receivers, but at appreciably lower cost.