DBMsOL and FBMsOL power spectral density masks
View Patent ↗In accordance with one embodiment of the present invention, a power spectral density (PSD) mask for spectral shaping of a dual bit map (DBM) mode downstream transmission is provided. The PSD mask is represented by the equation: PSD DBMsOL = K ADSL_OL × C f 0 × [ sin ( π f f 0 ) ] 2 ( π f f 0 ) 2 × 1 1 + ( f f LP3dB ) 12 × 1 1 + ( f HP3dB f ) 6 , 0 ≺ f ≺ ∞ where PSD DBMsOL represents the PSD mask, K ADSL — OL represents a constant value, C represents a constant value, f represents a frequency of the downstream transmission, f 0 represents a constant value, f LP3dB represents a 3 decibel (dB) low pass frequency and f f HP3dB represents a 3 dB high pass frequency. K ADSL — OL preferably has a value between 0.0900 watts and 0.1200 watts and more preferably has a value of 0.1104 watts. The constant f 0 preferably has a value between 2.100 megahertz and 2.300 megahertz and more preferably has a value of 2.208 megahertz. The constant f LP3dB has a value substantially equal to f 0 2 . The constant f HP3dB has preferably has a value between 100 kilohertz and 150 kilohertz and more preferably has a value of 130 kilohertz. The constant C preferably has a value between 0.1 and 10 and more preferably has a value of 2.
1. A Digital Subscriber Line (DSL) communications system comprising:
a central office Asynchronous Digital Subscriber Line (ADSL) transceiver unit (ATU-C) in discrete multitone (DMT) communication with a remote ADSL transceiver unit (ATU-R), wherein the ATU-C comprises a central office (CO) operator configured to perform spectral shaping of a dual bit map (DBM) mode downstream transmission based on a power spectral density (PSD) mask represented by the following equation:
PSD
DBMsOL
=
K
ADSL_OL
×
C
f
0
×
[
sin
(
π
f
f
0
)
]
2
(
π
f
f
0
)
2
×
1
1
+
(
f
f
LP3dB
)
12
×
1
1
+
(
f
HP3dB
f
)
6
,
0
≺
f
≺
∞
where PSD DBMsOL represents the PSD mask, K ADSL — OL represents a constant value, C represents a constant value, f represents a frequency of the downstream transmission, f 0 represents a constant value, f LP3dB represents a 3 decibel (dB) low pass frequency and f HP3dB represents a 3 dB high pass frequency.
2. The system as in claim 1 , wherein K ADSL — OL has a value between 0.0900 watts and 0.1200 watts.
3. The system as in claim 2 , wherein K ADSL — OL has a value of 0.1104 watts.
4. The system as in claim 1 , wherein f 0 has a value between 2.100 megahertz and 2.300 megahertz.
5. The system as in claim 4 , wherein f 0 has a value of 2.208 megahertz.
6. The system as in claim 1 , f LP3dB has a value substantially equal to
f
0
2
.
7. The system as in claim 1 , wherein f HP3dB has a value between 100 kilohertz and 150 kilohertz.
8. The system as in claim 7 , wherein f HP3dB has a value of 130 kilohertz.
9. The system as in claim 1 , wherein C has a value between 0.1 and 10.
10. The system as in claim 9 , wherein C has a value of 2.
11. The system as claim 10 , wherein f HP3dB has a value of 130 kilohertz.
12. The system as in claim 11 , f LP3dB has a value substantially equal to
f
0
2
.
13. The system as in claim 12 , wherein K ADSL — OL has a value of 0.1104 watts.
14. The system as in claim 13 , wherein f 0 has a value of 2.208 megahertz.
15. A Digital Subscriber Line (DSL) communications system comprising:
a central office Asynchronous Digital Subscriber Line (ADSL) transceiver unit (ATU-C) in discrete multitone (DMT) communication with a remote ADSL transceiver unit (ATU-R), wherein the ATU-C comprises a central office (CO) operator configured to perform spectral shaping of a far end cross talk (FEXT) bit map (FBM) mode downstream transmission based on a power spectral density (PSD) mask represented by the following equation:
PSD
FBMsOL
=
K
ADSL_OL
×
C
f
0
×
[
sin
(
π
f
f
0
)
]
2
(
π
f
f
0
)
2
×
1
1
+
(
f
f
LP3dB
)
12
×
1
1
+
(
f
HP3dB
f
)
8
,
0
≺
f
≺
∞
where PSD FBMsOL represents the PSD mask, K ADSL — OL represents a constant value, C represents a constant value, f represents a frequency of the downstream transmission, f 0 represents a constant value, f LP3dB represents a 3 decibel (dB) low pass frequency and f HP3dB represents a 3 dB high pass frequency.
16. The system as in claim 15 , wherein K ADSL — OL has a value between 0.0900 watts and 0.1200 watts.
17. The system as in claim 16 , wherein K ADSL — OL has a value of 0.1104 watts.
18. The system as in claim 15 , wherein f 0 has a value between 2.100 megahertz and 2.300 megahertz.
19. The system as in claim 18 , wherein f 0 has a value of 2.208 megahertz.
20. The system as in claim 15 , f LP3dB has a value substantially equal to
f
0
2
.
21. The system as in claim 15 , wherein f HP3dB has a value between 27 kilohertz and 40 kilohertz.
22. The system as in claim 21 , wherein f HP3dB has a value of 32 kilohertz.
23. The system as in claim 15 , wherein C has a value between 0.1 and 10.
24. The system as in claim 23 , wherein C has a value of 2.
25. The system as in claim 24 , wherein f HP3dB has a value of 32 kilohertz.
26. The system as in claim 25 , f LP3dB has a value substantially equal to
f
0
2
.
27. The system as in claim 26 , wherein K ADSL — OL has a value of 0.1104 watts.
28. The system as in claim 27 , wherein f 0 has a value of 2.208 megahertz.