Synchronized discrete multi-tone (SDMT) modulation for cable modems: making the most of the scarce reverse channel bandwidth

This paper describes synchronized discrete multi-tone (SDMT), a technique that enables the use of discrete multi-tone (DMT) in the reverse channel of cable or hybrid fiber-coax (HFC) networks. It is shown that SDMT achieves high spectral efficiencies, on the order of 4-5 bits/s/Hz, and offers resilience to common reverse channel impairments, including impulse noise, radiofrequency ingress, and spectral variability. The paper concludes that SDMT is a cost-effective solution that enables efficient, robust, high-speed upstream communications on cable and HFC networks