Trellis decoding with multiple symbol noncoherent detection and interleaving to combat frequency offset

摘要

A solution to the problem of frequency offset in a digital communication system. On the transmitter side, interleaving is applied to a stream of symbols to which an error correcting code has been applied. The interleaving is such that symbols of the stream are divided into two groups, e.g, alternating symbols are assigned to different groups. The result of interleaving is a burst where symbols of a first one of the group are transmitted in ascending order and symbols of a second one of the group are transmitted in descending order. In one embodiment, the second group comes first in the burst, then one or more synchronization symbols followed by the first group.