Feedback Timing Synchronization for IF-sampled Systems

Introduction Digital Intermediate Frequency (IF) receivers are achieving a widespread use, also in satellite applications. By means of this paradigm the received RF spectrum is moved down to IF, and digitization occurs at the low IF. Thereafter, digital signal processing techniques are used to extract the signal. When it comes to synchronization, some new issues arise due to the possibly di#erent sampling rates with respect to a conventional baseband receiver. In particular, a great deal of work has been carried out recently to study computationally feasible methods to reduce the sample rate before demodulation and detection [1], [2]. If we focus on timing recovery, conventional methods work with two or four samples per symbol, whether we talk of ad-hoc methods or we refer to maximum-likelihood based schemes [3], [4]. In any case, the number of samples per period is tried to keep at a minimum. The aim of this work is to analyze the timing recovery issue in IF-sampled systems, for whi