System and method for selectable mask for LDSL

• US 7,272,172 B2
• Filed: 11/18/2003
• Issued: 09/18/2007
• Est. Priority Date: 11/18/2002
• Status: Expired due to Fees

• Current Assignee: Synaptics Incorporated
• Original Assignee: Brooktree Broadband Holding, Inc. (Synaptics Incorporated)
• Inventors: Duvaut, Patrick, Langberg, Ehud
• Primary Examiner(s): Fan; Chieh M.
• Assistant Examiner(s): Pathak; Sudhanshu C.
• Application Number:
  US10/714,907
• Publication Number:
  US 20040136329A1
• Time in Patent Office: 1,400 Days
• Field of Search: 375/260, 375/222, 375/219, 375/224, 375/220
• US Class Current: 375/222
• CPC Class Codes: H04Q 11/04 for time-division multiplexing H04Q11/0001 takes precedence
• CPC Class Codes: H04Q 2213/13039 Asymmetrical two-way transmission, e.g. ADSL, HDSL
• CPC Class Codes: H04Q 2213/13094 Range extender
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13396 Signaling in general, in-band signalling

Abstract

The present invention overcomes various problems by defining two upstream masks (U1, U2) and two downstream masks (D1, D2) and using a mask selectable system for the long reach digital subscriber line (LDSL), in which a unique modem feature is activated during handshake to automatically check for physical layer status in terms of spectral compatibility and, thus, automatically optimize the boosted mode with the use of the mask selectable system choose the best combination of upstream/downstream masks in any physical layer noise scenario.

Claims

1. A method for selecting a spectral mask for use with a DSL system, the method comprising:

obtaining a weighted ratio of upstream rates and downstream rates;

determining whether a cost function, based in part upon the weighted ratio, is greater than a predetermined value, wherein determining whether a cost function is greater than a predetermined value further comprises;

determining a cost function according to the relation;

cost function =2*(dsrate(2)−

dsrate(1)/dsrate(1)+(usrate(2)−

usrate(1))/usrate(1), wherein dsrate(1) is the downstream rate of a first mask, dsrate(2) is the downstream rate of a second mask, usrate(1) is the upstream rate of the first mask and usrate(2) is the upstream rate of the second mask; and

selecting a spectral mask based in part upon the determination of whether the cost function is greater than a predetermined value.

2. The method of claim 1 wherein the predetermined value is zero and wherein, if the cost function is greater than zero, the second mask is selected.

3. The method of claim 1 wherein the f is a frequency band in kHz and the upstream value of the first mask is given by the following relations for U1 in dBm/Hz:

for 0≦

f<

4, then U1=−

101.5;

for 4<

f<

25.875, then U1=−

96+23.4*log₂(f/4);

for 25.875≦

f<

60.375, then U1=−

32.9;

for 60.375≦

f<

686, then U1=max{−

32.9−

95×

log₂(f/60.38), 10×

log10[0.05683×

(f×

10³)<sup>−

1.5</sup>]−

3.5};

for 686≦

f<

1411, then U=−

103.5;

for 1411≦

f<

1630, then U1=−

103.5 peak, −

113.5 average in any [f, f+1 MHz] window; and

for 1630≦

f<

12000, then U1=−

103.5 peak, −

115.5 average in any [f, f+1 MHz] window.

4. The method of claim 1 wherein the f is a frequency band in kHz and the downstream value of the first mask is given by the following relations for D1 in dBm/Hz:

for 0≦

f<

4, then D1=−

101;

for 4≦

f<

25.875, then D1=−

96+20.79*log₂(f/4);

for 25.875≦

f<

91, then D1=−

40;

for 91≦

f<

99.2, then D1=−

44;

for 99.2≦

f<

138, then D1=−

52;

for 138.ltoreq.f<

353.625, then D1=−

40.2+0.0148*(f−

138);

for 353.625≦

f<

552, then D1=−

37;

for 552≦

f<

1012, then D1 =−

37−

36*log₂(f/552);

for 1012≦

f<

1800, then D1=−

68.5;

for 1800≦

f<

2290, then D1=−

68.5−

72*log₂(f/1800);

for 2290≦

f<

3093, then D1=−

93.500;

for 3093≦

f<

4545, then D1=−

93.5 peak, average −

40−

36*log₂(f/1104) in any [f, f+1 MHz] window; and

for 4545≦

f<

12000, then D1=−

93.5 peak, average −

113.500 in any [f, f+1 MHz] window.

5. The method of claim 1 wherein the f is a frequency band in kHz and the upstream value of the second mask is given by the following relations for U2 in dBm/Hz:

for 0≦

f<

4, then U2=−

101.5;

for 4≦

f<

25.875, then U2=−

96+21.5×

log₂(f/4);

for 25.875≦

f<

103.5, then U2=−

36.4;

for 103.5≦

f<

686, then U2=max{−

36.3−

95×

log₂(f/103.5), 10×

log10[0.05683×

(f−

×

10³)<sup>−

1.5</sup>]−

3.5};

for 686≦

5f<

1411, then U2=−

103.5;

for 1411≦

f<

1630, then U2=−

103.5 peak, −

113.5 average in any [f, f+1 MHz] window; and

for 1630≦

f<

12000, then U2=−

103.5 peak, −

115.5 average in any [f, f+1 MHz] window.

6. The method of claim 1 wherein the f is a frequency band in kHz and the downstream value of the second mask is given by the following relations for D2 in dBm/Hz:

for 0≦

f<

4, then D2=−

101.5;

for 4≦

f<

80, then D2=−

96+4.63*log₂(f/4);

for 80≦

f<

138, then D2=−

76+36*log₂(f/80);

for 138≦

f<

276.000;

then D2=−

42.95+0.0214*f;

for 276≦

f<

552.000;

then D2=−

37;

for 552≦

f<

1012, then D2=−

37−

36*log₂(f/552);

for 1012≦

f<

1800, then D2=−

68.5;

for 1800≦

f<

2290, then D2=−

68.5−

72*log₂(f/1800);

for 2290≦

f<

3093, then D2=−

93.5;

for 3093≦

f<

4545, then D2=−

93.5 peak, average −

40−

36*log₂(f/1104) in any [f, f+1 MHz] window; and

for 4545≦

f<

12000, then D2-−

93.5 peak, average −

113.500 in any [f, f+1 MHz] window.