Upstream Channel Synchronization for Cable Modem System

The upstream of digital cable modem is a burst mode transmission system, where a burst contains the preamble and data. In this paper, we consider algorithms for the symbol timing, carrier frequency- and phase-offset recovery for the upstream cable modem, that are compliant to DOCSIS 2.0. Several algorithms are tested and verified to find the best algorithm for each of the three recovery blocks, respectively. To fit to the DOCSIS specification, Oerder & Meyr´s is chosen for the timing recovery algorithm, Mengali & Morelli´s is chosen for the carrier frequency-offset recovery algorithm and Cartwright´s is chosen for blind carrier phase recovery. We decide the optimal preamble length for these algorithms and check the error variance. Finally, we show the error performance of the entire system.