Equalized SNR power back-off
AssigneeAnalog Devices, Inc.
InventorVladimir Friedman
Life of this patent
Estimating the term…
Abstract
A power back-off system and method to mitigate far-end crosstalk interference between channels in a communication system through a generalization of the reference length and equalized FEXT methods, a power back-off method is provided that allows for control over the SNR of the channels by trading SNR on shorter channels against SNR on the longer channels. The generalization also provides for a power back-off method that can provide for two or more data rate service areas.
Claims31
A power back-off method to mitigate the effects of FEXT noise in a communication system comprising at least one transmitter k, the transmitter k transmitting to a central site via a corresponding channel, the method comprising:
- determining a transmit power spectral density for the transmitter k, S(f,lk), according to:
- 17 S ( f , l k ) = ( l k l R ) υ S ( f , l R ) · [LeftBracketingBar] H ( f , l R ) [RightBracketingBar] 2 [LeftBracketingBar] H ( f , l k ) [RightBracketingBar] 2 for l k ≤ l R
- wherein lk is a channel length of the channel corresponding to the transmitter k, H(f,lk) is a channel transfer function of the channel corresponding to the transmitter k, lR is a reference channel length, H(f,lR) is a reference channel transfer function, S(f,lR) is a reference transmit power spectral density, and υ≠−1 or 0;
- and
- controlling transmitter k to transmit at the transmit power spectral density S(f,lk).
A communication system comprising:
- at least one transmitter k, the transmitter transmitting to the central site with a transmit power spectral density S(f,lk) via a corresponding channel, wherein the channel has a length lk and a channel transfer function H(f,lk);
- and
- wherein the transmit power spectral density S(f,lk) is governed according to:
- 18 S ( f , l k ) = ( l k l R ) υ S ( f , l R ) · [LeftBracketingBar] H ( f , l R ) [RightBracketingBar] 2 [LeftBracketingBar] H ( f , l k ) [RightBracketingBar] 2 for l k ≤ l R
- where lR is a reference channel length, H(f,lR) is a reference channel transfer function, S(f,lR) is a reference transmit power spectral density, and υ≠−1 or 0.
A transmitter that transmits on a channel with a transmit power spectral density S(f,lk) according to:
- 19 S ( f , l k ) = ( l k l R ) υ S ( f , l R ) · [LeftBracketingBar] H ( f , l R ) [RightBracketingBar] 2 [LeftBracketingBar] H ( f , l k ) [RightBracketingBar] 2 for l k ≤ l R
- wherein lk is a channel length of the channel, H(f,lk) is a channel transfer function of the channel, S(f,lR) is a reference transmit power spectral density, lR is a reference channel length, H(f,lR) is a reference channel transfer function, and υ≠−1 or 0.
A transmitter that transmits on a channel in a communication system, wherein the transmitter transmits with a transmit power spectral density that is controlled to provide substantially equal data rates for each channel in the communication system.
A power back-off method to mitigate the effects of FEXT noise in a communication system comprising at least one transmitter k, the transmitter k transmitting to a central site via a corresponding channel, the method comprising:
- determining the transmit power spectral density for the transmitter k, S(f,lk), according to:
- 21 S ( f , l k ) = G · ( l k l R ) υ S ( f , l R ) · [LeftBracketingBar] H ( f , l R ) [RightBracketingBar] 2 [LeftBracketingBar] H ( f , l k ) [RightBracketingBar] 2 for l k ≤ l R
- wherein lk is a channel length of the channel corresponding to the transmitter k, H(f,lk) is a channel transfer function of the channel corresponding to the transmitter k, lR is a reference channel length, H(f,lR) is a reference channel transfer function, S(f,lR) is a reference transmit power spectral density, and G has a value that depends on the channel length lk such that two or more data rate service areas are defined;
- and
- controlling transmitter k to transmit at the transmit power spectral density S(f,lk).
A communication system comprising:
- at least one transmitter k, the transmitter transmitting to the central site with a transmit power spectral density S(f,lk) via a corresponding channel, wherein the channel has a length lk and a reference channel transfer function H(f,lk);
- and
- wherein the transmit power spectral density S(f,lk) is governed according to:
- 22 S ( f , l k ) = G · ( l k l R ) υ S ( f , l R ) · [LeftBracketingBar] H ( f , l R ) [RightBracketingBar] 2 [LeftBracketingBar] H ( f , l k ) [RightBracketingBar] 2 for l k ≤ l R
- where lR is a reference channel length, H(f,lR) is a reference channel transfer function, S(f,lR) is a reference transmit power spectral density, and G has a value that depends on the channel length lk such that two or more data rate service areas are defined.
A transmitter that transmits on a channel in a communication system, wherein the transmitter transmits with a transmit power spectral density S(f,lk) according to:
- 23 S ( f , l k ) = G · ( l k l R ) υ S ( f , l R ) · [LeftBracketingBar] H ( f , l R ) [RightBracketingBar] 2 [LeftBracketingBar] H ( f , l k ) [RightBracketingBar] 2 for l k ≤ l R
- wherein lk is a channel length of the channel that the transmitter transmits on, H(f,lk) is a channel transfer function of the channel that the transmitter transmits on, S(f,lR) is a reference transmit power spectral density, lR is a reference channel length, H(f,lR) is a reference channel transfer function, and G has a value that depends on the channel length lk such that two or more data rate service areas are defined.
Dependencies are inferred from the claim text.