Selectable training signals based on stored previous...

Details Selectable training signals based on stored previous... Selectable training signals based on stored previous...

2011-06-07

2011-06-07

Ho, Duc C (Department: 2465)

Multiplex communications

Diagnostic testing

Determination of communication parameters

C370S484000, C370S465000

Reexamination Certificate

active

07957308

ABSTRACT:
In a DMT based system, training signals can be chosen based on stored prior connection information to reduce using extra tones in transmitted training signals to improve receiver performance. By choosing training signals based on the stored prior connection information, training signals may be made to indirectly represent a function of the loop impairments. Certain training signal tones in the training signals may be omitted, based on previous connection information, on a loop-by-loop basis. Local echoes are effectively reduced and local receiver training is improved without affecting eventual data transmission performance. Higher AGC gain and higher signal-to-quantization-noise ratios can be achieved, especially in the case of long loops. These benefits can allow (1) improvements in the loop performance in the receiving direction and/or (2) reductions in the requirements on the receiving ADC. Crosstalks into other wire pairs of a bundle, are reduced, improving the transmission environment on those pairs.

REFERENCES:
patent: 5533008 (1996-07-01), Grube et al.
patent: 5557612 (1996-09-01), Bingham
patent: 5999540 (1999-12-01), McGhee
patent: 6324268 (2001-11-01), Balachandran et al.
patent: 6345071 (2002-02-01), Hamdi
patent: 6408033 (2002-06-01), Chow et al.
patent: 6516027 (2003-02-01), Kapoor et al.
patent: 6587502 (2003-07-01), Hendrichs et al.
patent: 6611564 (2003-08-01), Linz et al.
patent: 6628704 (2003-09-01), Long et al.
patent: 6674795 (2004-01-01), Liu et al.
patent: 6718019 (2004-04-01), Heidari et al.
patent: 6804267 (2004-10-01), Long et al.
patent: 6922397 (2005-07-01), Chen
patent: 7187696 (2007-03-01), Chen
patent: 2001/0048667 (2001-12-01), Hamdi
patent: 2002/0041643 (2002-04-01), Tzannes et al.
patent: 2003/0026282 (2003-02-01), Gross et al.
patent: 2005/0129103 (2005-06-01), Palm
patent: WO 99/20027 (1999-04-01), None
patent: WO 99/48304 (1999-09-01), None
patent: WO 01/95580 (2001-12-01), None
Bingham, “ADSL, VDSL, and Multicarrier Modulation”, John Wiley & Sons Inc. 2000, 303 pages.
Cioffi et al., “A Data Driven Multitone Echo Cnaceller”, IEEE Transactions on Communications, vol. 42, No. 10, Oct. 1994, pp. 2853-2869.
ITU-T Recommendation G.992.1, Asymmetric Digital Subscriber Line (ADSL) Transceivers, 1999, pp. 256.
ITU-T Recommendation G-992.2, Splitterless Asymmetric Digital Subscriber Line (ADSL) Transceivers, 1999, pp. 1-170.
3Com® Base Level ADSL Interoperability Specification, Discrete Multi-Tone (DMT), Lucent Technologies, Bell Labs Innovations, Revision 1.0.43, updated May 22, 1998, 16 pp.

Affiliated with

Also associated with

Rating

Selectable training signals based on stored previous... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Selectable training signals based on stored previous..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Selectable training signals based on stored previous... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2683876