04117277 is referenced by 26 patents and cites 4 patents.

An arrangement for simultaneous two-way data transmission of data signals with a given symbol frequency over two-wire circuits of a type found in telephone networks or of a comparable type. The arrangement comprises an echo canceler with an adaptive filter for producing from transmit channel signals approximated echo signals which are differentially combined with receive channel signals for forming substantially echo-free residual signals. A special type of code conversion is employed in the transmit channel, whereby p-level data symbols are converted into modified p-level data symbols which are thereafter converted into (2p-1)-level data symbols. The echo canceler comprises a digital adaptive filter to which the modified p-level data symbols and the residual signals with a sampling frequency equal to the symbol frequency are supplied. These measures result in a transmission signal having favorable spectral properties, a simple inverse code conversion and an echo canceler which combines simplicity of implementation with favorable convergence properties.

Title
Arrangement for simultaneous two-way data transmission over two-wire circuits
Application Number
5/807008
Publication Number
4117277
Application Date
June 16, 1977
Publication Date
September 26, 1978
Inventor
Wilfred Andre Maria Snijders
Eindhoven
NL
Petrus Josephus VAN Gerwen
Eindhoven
NL
Hendricus Christianus van den Elzen
Eindhoven
NL
Agent
Henry I Steckler
Frank R Trifari
Assignee
U S Philips Corporation
NY, US
IPC
H04B 3/20
View Original Source