Evaluation of transmission alternatives for the return cable band

This research concerns comparing the performance of various transmission and reception alternatives for the 5-45 MHz portion of the upstream path of the return coaxial cable band. This evaluation is based on ingress noise spectra files collected over an extended period of time from various sites. This data has been used to evaluate the return band capacity as a function of sub-channel bandwidth in FDMA and TDMA/FDMA schemes. In addition, the time varying aspect of the channel is considered using variable bit rate allocation to sub-bands, as in OFDM with frequency division multiplexing. Furthermore, the same analysis is repeated for a wideband system using a decision feedback equalizer (WDFE) contending with ingress noise instead of channel distortion. This research demonstrates that using a variable channel allocation (VCA) scheme to match the time varying aspect of the channel enhances the performance over a fixed channel allocation (FCA) scheme. It also shows that a wideband system using an adaptive decision feedback equalizer (DFE) performs similar to a multi-carrier modulation (MCM) method, and that reasonable performance can be obtained by using a system of lower complexity consisting of the combination of the FCA with the WDFE.