Paper Info
Title
Design Considerations for a 144 kbit/s Digital Transmission Unit for the Local Telephone Network
Abstract
In this paper a digital transmission unit for the forthcoming integrated services digital network (ISDN) is considered. Basic elements of such a unit are an adaptive echo canceller (EC) and an adaptive decision feedback equalizer (DFE). Each of these filters can be realized by a transversal filter structure or by a lookup table structure. An analysis and comparison of the behavior of these two structures is given, The combination of an EC and a DFE can also be realized by a single lookup table. It is shown that irrespective of the particular realization three different convergence phases can be distinguished, and that the overall convergence time is considerably longer then would be expected from the usual simple theory that ignores error propagation in the DFE. Two variants of a hardware realization of such a digital transmission unit are presented. They provide 144 kbit/s full-duplex transmission on the symmetrical cables of the existing local telephone network. A small transmission bandwidth is obtained by applying NRZ signaling. In the first circuit the EC and DFE are implemented by individual lookup tables, while in the second a combined table is used. Both circuits are to a large extent, implemented digitally. Due to the relatively low sampling frequency and the acceptably low power consumption they are very well suited for large scale integration with present day technology.
Year
DOI
Venue
1984
10.1109/JSAC.1984.1146057
IEEE Journal on Selected Areas in Communications
Field
DocType
Volume
Telephone network,Convergence (routing),Lookup table,Integrated Services Digital Network,Propagation of uncertainty,Data transmission,Computer science,Sampling (signal processing),Computer network,Real-time computing,Electronic circuit
Journal
2
Issue
Citations 
PageRank 
2
12
5.62
References 
Authors
5
3
Name
Order
Citations
PageRank
P. Van Gerwen12910.63
N. Verhoeckx2198.66
Claasen, Theo A.C.M.35925.32