Channel allocation and reallocation in a communication system

• US 20030179770A1
• Filed: 10/18/2002
• Published: 09/25/2003
• Est. Priority Date: 02/28/2002
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Sommer, Naftali, Reznic, Zvi, Lusky, Itay, Bendel, Yosef
• Application Number:
  US10/273,560
• Publication Number:
  US 20030179770A1
• Time in Patent Office: Days
• US Class Current: 370/442
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0017 where the mode-switching is based on Quality of Service requirement
• CPC Class Codes: H04L 1/0019 in which mode-switching is based on a statistical approach
• CPC Class Codes: H04L 1/20 using signal quality detector

Abstract

A method is provided for automatically allocating a channel, in a communication system, having a total data rate for transmitting and receiving signals, each of the signals having a carrier frequency, a baud rate and a constellation size, the channel comprising a frequency band comprising a plurality of carrier frequencies, comprising the steps of: receiving a noise sample from the channel; determining a channel noise estimate for the noise sample; receiving a parameter indicating a maximum allowed bit error rate; scanning one or more possible combinations of carrier frequency and baud rate for the channel; determining the bit error rate for each combination based on the channel noise estimate; determining what constellation sizes can be used for each combination such that the bit error rate for that combination does not exceed the maximum allowed bit error rate; determining a data rate for one or more of the combinations; and allocating the channel such that the total data rate is maximized. Other systems and methods are disclosed.

Claims

1. A method for automatically allocating a channel, in a communication system, having a total data rate for transmitting and receiving signals, each of the signals having a carrier frequency, a baud rate and a constellation size, the channel comprising a frequency band comprising a plurality of carrier frequencies, comprising the steps of:

a. receiving a noise sample from the channel;

b. determining a channel noise estimate for the noise sample;

c. receiving a parameter indicating a maximum allowed bit error rate;

d. scanning one or more possible combinations of carrier frequency and baud rate for the channel;

e. determining the bit error rate for each combination based on the channel noise estimate;

f. determining what constellation sizes can be used for each combination such that the bit error rate for that combination does not exceed the maximum allowed bit error rate;

g. determining a data rate for one or more of the combinations; and

h. allocating the channel such that the total data rate is maximized.

2. The method of claim 1 further comprising a digital front for receiving the noise sample from a first channel where active transmission is not occurring while active transmission is occurring on a second channel.

3. The method of claim 1 further comprising the step of canceling highly correlated noise from the channel noise estimate.

4. The method of claim 3 wherein the highly correlated noise is ingress noise.

5. The method of claim 1 further comprising the step of reallocating the channel during time periods when no active transmission is occurring on the channel.

6. A method for automatically reallocating a channel for transmitting and receiving signals in a communication system, the channel having a total data rate, each of the signals having a carrier frequency, a baud rate and a constellation size, the channel comprising a frequency band comprising a plurality of carrier frequencies, comprising the steps of:

a. determining a time period when active transmission is not occurring on the channel;

b. receiving a noise sample from the channel during the time period;

c. determining a channel noise estimate for the noise sample;

d. receiving a parameter indicating a maximum allowed bit error rate;

e. scanning one or more possible combinations of carrier frequency and baud rate for the channel;

f. determining the bit error rate for each combination based on the channel noise estimate;

g. determining what constellation sizes can be used for each combination such that the bit error rate for that combination does not exceed the maximum allowed bit error rate;

h. determining a data rate for one or more of the combinations; and

i. reallocating the channel such that the total data rate is maximized.

7. The method of claim 6 further comprising the step of canceling highly correlated noise from the channel noise estimate.

8. The method of claim 7 wherein the highly correlated noise is ingress noise.

9. A system for automatically allocating a channel in a communication system having a total data rate for transmitting and receiving signals, each of the signals having a carrier frequency, a baud rate and a constellation size, the channel comprising a frequency band comprising a plurality of carrier frequencies, comprising:

a. a performance estimator coupled to the channel for receiving a noise sample from the channel, the performance estimator having an output estimating carrier frequency, baud rate and constellation size combinations such that a maximum allowed bit error rate is not exceeded; and

b. a frequency allocator coupled to the output of the performance estimator for allocating in the channel one or more of the carrier frequency, baud rate, and constellation size combinations such that the total data rate is maximized.

10. The system of claim 9 further comprising a digital front end coupled to the channel and coupled to the performance estimator for receiving the noise sample from a first channel where active transmission is not occurring while active transmission is occurring on a second channel.

11. The system of claim 9 wherein the performance estimator simulates highly correlated noise cancellation.

12. The system of claim 11 wherein the highly correlated noise is ingress noise.