Coexistence of 2-10 Mbps Home-Phone LANS and DMT VDSL via Multiuser Detection

This document augments contribution T1E1.4/99-120 by investigating the QAM transmission methods used for higher-speed Home-phone LANs (HPL), specifically 2-10 Mbps with symbol rates of 2-4 MHz. While higher speed, these newer HPL transmission methods are suggested to be easier for multiuser detection with respect to the pulse position modulation schemes used for earlier Home PNA 1.0 networks, because of the inefficiency of the PPM transmission technology in terms of bits/Hz. DMT VDSL with narrow-band nulling of selected tones within the 4-10 MHz HPL band was specifically investigated and found to be necessary to obtain sufficiently high minimum distance properties for successful multiuser detection. Very little degradation is evident for the situation of a single HPL crosstalker with multiuser detection, while huge degradation is evident with a single-user detector. The issue of complexity is addressed briefly in suggesting that iterative multiuser decoding and some code-division concepts for VDSL HPL crosstalking environments be placed on the VDSL issues list. This issue has a further sub-item suggestion in that scalable data rates of VDSL be investigated specifically in the context of HPL because not all VDSL data-rate configurations overlap the HPL frequency band. ________________________________________________________________________ NOTICE This contribution has been prepared to assist Standards Committee T1 Telecommunications. This document is offered to the Committee as a basis for discussion and is not a binding on any of the companies listed as authors. The requirements are subject to change after further study. The authors specifically reserve the right to add to, amend, or withdraw the statements contained herein. 06/04/99 2 T1E1.4/99-333 Coexistence of 1 Mbps HPNA and DMT VDSL via Multiuser Detection and Code-Division Multiplexing (99-120) K.W. Cheong and J.M. Cioffi Information Systems Laboratory Stanford University Stanford, CA 94305 Phone: 650-723-2150 ; Fax: 650-723-8473 Abstract This document augments contribution T1E1.4/99-120 by investigating the QAM transmission methods used for higher-speed Home-phone LANs (HPL), specifically 2-10 Mbps with symbol rates of 2-4 MHz. While higher speed, these newer HPL transmission methods are suggested to be easier for multiuser detection with respect to the pulse position modulation schemes used for earlier Home PNA 1.0 networks, because of the inefficiency of the PPM transmission technology in terms of bits/Hz. DMT VDSL with narrow-band nulling of selected tones within the 4-10 MHz HPL band was specifically investigated and found to be necessary to obtain sufficiently high minimum distance properties for successful multiuser detection. Very little degradation is evident for the situation of a single HPL crosstalker with multiuser detection, while huge degradation is evident with a single-user detector.This document augments contribution T1E1.4/99-120 by investigating the QAM transmission methods used for higher-speed Home-phone LANs (HPL), specifically 2-10 Mbps with symbol rates of 2-4 MHz. While higher speed, these newer HPL transmission methods are suggested to be easier for multiuser detection with respect to the pulse position modulation schemes used for earlier Home PNA 1.0 networks, because of the inefficiency of the PPM transmission technology in terms of bits/Hz. DMT VDSL with narrow-band nulling of selected tones within the 4-10 MHz HPL band was specifically investigated and found to be necessary to obtain sufficiently high minimum distance properties for successful multiuser detection. Very little degradation is evident for the situation of a single HPL crosstalker with multiuser detection, while huge degradation is evident with a single-user detector. The issue of complexity is addressed briefly in suggesting that iterative multiuser decoding and some code-division concepts for VDSL HPL crosstalking environments be placed on the VDSL issues list. This issue has a further sub-item suggestion in that scalable data rates of VDSL be investigated specifically in the context of HPL because not all VDSL data-rate configurations overlap the HPL frequency band.