Multi-Frame Synchronization for a DTV Receiver: CFO, SFO, and Error Performance Analysis

Abstract

Synchronization is an important design problem for communication receivers, particularly in multipath channel scenarios. Further challenges arise due to the carrier frequency offset (CFO) caused by a mismatch in frequency of the local oscillators. The implementation is also limited by sampling frequency offset (SFO) associated with the drift of crystal oscillators. To account for these challenges, we propose a simple time domain correlation technique that relies on extending the preamble sequence via observing multiple data frames. We consider digital television as an example to show the effectiveness of the proposed technique. Due to self-resolving capability of the multipath components, the technique offers better performance in terms of peak to side-peak ratio than the conventional single preamble-based technique that correlates with a local reference. Owing to an extended preamble in the observation period, the proposed technique is shown to be robust against CFO. Besides, it is demonstrated that the technique shows resilience even in the presence of a strong SFO. Our theoretical analysis and simulated results are found to be in good match concerning peak to noise ratio. Finally, we derive a closed-form expression to compute the probability of the synchronization error that provides further insight into the performance gain offered by the proposed technique.