An Economical, ISI-Immune Frequency Offset Estimator for DOCSIS Upstream Channels

作者：Berscheid Brian^*; Salt Eric; Nguyen Ha H

来源：IEEE Transactions on Broadcasting, 2012, 58(2): 310-316.

DOI：10.1109/TBC.2012.2190192

• Cable networks
• Cramer-Rao bound
• frequency offset estimation
• intersymbol interference
• synchronization

This paper discusses the design and implementation of frequency offset estimation algorithms for DOCSIS upstream channels. A cost-effective estimator which approaches the Cramer-Rao bound for high SNRs is derived. The effect of ISI generated by upstream micro-reflections in typical cable networks is considered, and a condition upon the transmitted preamble sequence which guarantees unbiased estimation is presented. It is shown that the proposed estimator is unbiased for a wide range of preamble sequences, which is generally not the case for burst frequency estimators. This flexibility may be utilized by selecting a broadband preamble which is suitable for performing channel estimation and frequency offset estimation simultaneously, thereby increasing the efficiency of the upstream channels.

• 出版日期2012-6