Frame synchronization with large carrier frequency offsets: Point estimation versus hypothesis testing

In communication systems which transmit a continuous stream of data, the coded data symbols are typically transmitted in frames. Frames contain one or multiple blocks of coded data. The Start Of a Frame (SOF) is especially required to synchronize the decoder, especially in systems which use modern codes such as Turbo codes. This process is known as frame synchronization. We examine the general problem of frame synchronization in the presence of a large residual carrier frequency offset, and study the theoretical and implementation trade-offs between using point estimation and sequential detection in deriving frame synchronizers. We also derive a new sequential detector which is resilient to Automatic Gain Control (AGC) errors. We describe simple state machines which control the one-shot point estimator and the sequential detector to ensure low probability of false detects. We compare the two techniques via simulation results and also a simple Markov chain analysis of the point-estimation scheme.