Method and apparatus for configuring a communication system

• US 6,775,241 B1
• Filed: 12/01/1999
• Issued: 08/10/2004
• Est. Priority Date: 09/25/1997
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Levin, Howard E.
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): George, Keith M.
• Application Number:
  US09/451,532
• Time in Patent Office: 1,714 Days
• Field of Search: 370/210, 370/252, 370/282, 370/468, 370/484, 370/485, 370/486, 370/487, 375/219, 375/220, 375/222, 375/225, 375/227, 375/377, 455/63, 455/67.14, 455/422
• US Class Current: 370/252
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path

Abstract

The present invention comprises a remote terminal (20) and a central office (30) as part of and ADSL system (10). Once a communication channel is open between the remote terminal (20) and the central office (30), the remote terminal (20) transmits channel specific information, application specific information, or both to the central office (30). Once the central office (30) receives the information, the central office (30) can select data rate options optimized for the downstream receiver (the remote terminal (20)). Based on the application specific and/or channel specific information, the central office (30) can use a combination of calculations and look-up tables to formulate new options. When the remote terminal (20) sends channel specific information, the central office (30) can perform calculations which determine performance margins at various data rates.

Claims

1. A method of configuring a communication system, the method comprising the steps of:

providing a communication system having a first transceiver and a second transceiver;

the first transceiver determining a usable number of carriers for data reception; and

the second transceiver determining a reception rate of the first transceiver to be communicated to the first transceiver based upon the usable number of carriers without receiving any measured signal to noise ratios for a multi-carrier communication channel between the second transceiver and the first transceiver, the signal to noise information measured at the first transceiver.

2. The method of claim 1, further comprising the steps of:

the first transceiver determining a performance margin at a specified capacity; and

the second transceiver determining the reception rate to be communicated to the first transceiver based upon the usable number of carriers and the performance margin at the specified capacity.

3. The method of claim 2, further comprising the steps of:

the first transceiver determining a channel capacity; and

the second transceiver determining the reception rate to be communicated to the first transceiver based upon the channel capacity, the performance margin at the specified capacity and the usable number of carriers.

4. The method of claim 3, further comprising the step of the second transceiver modifying the performance margin based upon coding information to determine a new performance margin at a different data rate or to determine a new data rate at a different performance margin.

5. The method of claim 1, further comprising the steps of:

the first transceiver determining a channel capacity; and

the second transceiver determining the reception rate to be communicated to the first transceiver based upon the channel capacity and the usable number of carriers.

6. The method of claim 5, wherein the step of the first transceiver determining a channel capacity further comprises the first transceiver determining the channel capacity, wherein the channel capacity is a maximum channel capacity.

7. The method of claim 1 further comprising the steps of:

the second transceiver transmitting a first plurality of suggested data rates to the second transceiver,

the second transceiver calculating a second plurality of suggested data rates based upon the usable number of carriers determined at the first transceiver;

the second transceiver transmitting the second plurality of suggested data rates to the first transceiver; and

configuring the first transceiver at one of the second plurality of suggested data rates.

8. A method for communicating over a multicarrier communication channel, the method comprising:

providing a first data rate value;

providing a second data rate value based upon the multicarrier communication channel;

determining a performance margin of the multicarrier communication channel at the first data rate value based upon the second data rate value, without receiving any measured signal to noise ratios for each carrier within the multicarrier communication channel;

providing an incremental signal-to-noise ratio value; and

the step of determining the performance margin further comprises determining the performance margin of the multicarrier communication channel at the first data rate value base upon the second data rate value and the incremental signal-to-noise ratio value.

9. The method of claim 8, wherein the step of providing the incremental signal-to-noise ratio value further comprises:

providing the incremental signal-to-noise ratio value, wherein the incremental signal-to-noise ratio value is an average signal-to-noise between consecutive bit capacities in a carrier.

10. The method of claim 8, wherein the step of providing the incremental signal-to-noise ratio value further comprises:

providing the incremental signal-to-noise ratio value, wherein the incremental signal-to-noise ratio value is an average signal-to-noise interval between consecutive entries in an signal-to-noise reference table.

11. The method of claim 8, wherein the step of providing the incremental signal-to-noise ratio value further comprises:

providing the incremental signal-to-noise ratio value, wherein the incremental signal-to-noise ratio value approximately 3.

12. The method of claim 8, further comprising the steps of:

providing a number of usable bins at the second data rate value; and

the step of determining the performance margin further comprises determining the performance margin of the multicarrier communication channel at the first data rate value based upon the second data rate value, the incremental signal-to-noise ratio value and the number of usable bins.

13. The method of claim 12, further comprising the steps of:

providing a performance margin value at the second data rate value; and

the step of determining further comprises determining the performance margin of the multicarrier communication channel at the first data rate value based upon the second data rate value, the incremental signal-to-noise ratio value, the number of usable bins, and performance margin value at the second data rate value.

14. A method for communicating over a multicarrier communication channel, the method comprising:

providing a first data rate value;

providing a second data rate value based upon the multicarrier communication channel;

determining a performance margin of the multicarrier communication channel at the first data rate value based upon the second data rate value, without receiving measured signal to noise ratios for any carrier within the multicarrier communication channel;

providing a performance margin value at the second data rate value; and

the step of determining further comprises determining the performance margin of the multicarrier communication channel at the first data rate value based upon the second data rate value and the performance margin value at the second data rate value.

15. A method for communicating over a multicarrier communication channel, the method comprising:

providing a desired performance margin of the multicarrier communication channel;

providing a second data rate value based upon the multicarrier communication channel;

determining a data rate at the desired performance margin based upon the second data rate value without receiving a measured signal to noise ratio data for any carrier within the multicarrier communication channel;

providing an incremental signal-to-noise ratio value; and

the step of determining the data rate further comprises determining the data rate of the

multicarrier communication channel at the desired performance margin of the multicarrier communication channel based upon the second data rate value and the incremental signal-to-noise ratio value.

16. The method of claim 15, further comprising the steps of:

providing a number of usable bins at the data rate; and

the step of determining the data rate further comprises determining the data rate of the multicarrier communication channel at the desired performance margin, of the multicarrier communication channel based upon the data rate, the incremental signal-to-noise ratio value and the number of usable bins.

17. The method of claim 16 further comprising the steps of:

providing a performance margin value at the second data rate value, wherein the performance margin value at the second data rate value; and

the step of determining the data rate value further comprises determining the data rate value of the multicarrier communication channel at the desired performance margin of the multicarrier communication channel based upon the second data rate value, the incremental signal-to-noise ratio value, the number of usable bins, and the performance margin value at the second data rate value.

18. A method for communicating over a multicarrier communication channel, the method comprising:

providing a desired performance margin of the multicarrier communication channel;

providing a second data rate value based upon the multicarrier communication channel;

determining a data rate at the desired performance margin based upon the second data rate value without receiving a measured signal to noise ratio for any carrier within the multicarrier communication channel;

providing a performance margin value at the second data rate value; and

the step of determining the data rate value further comprises determining the data rate value of the multicarrier communication channel at the desired performance margin of the multicarrier communication channel based upon the second data rate value and the performance margin value at the second data rate value.