Method and apparatus for varying power levels in a multicarrier modem

• US 6,549,520 B1
• Filed: 05/17/2000
• Issued: 04/15/2003
• Est. Priority Date: 10/10/1997
• Status: Expired due to Term

• Current Assignee: Intellectual Ventures II LLC (Intellectual Ventures LLC)
• Original Assignee: Aware Incorporated (Crowley Holdings Preferred LLC)
• Inventors: Krinsky, David M., Greszczuk, John A., Tzannes, Michael A., Tzannes, Marcos, Gross, Richard W.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Elallam, Ahmed
• Application Number:
  US09/573,816
• Time in Patent Office: 1,063 Days
• Field of Search: 370/229, 370/242, 370/252, 370/271, 370/282, 370/286, 370/290, 370/292, 370/295, 370/352, 370/410, 370/437, 370/463, 370/465, 370/468, 370/477, 370/478, 370/480, 370/485, 370/493, 379/394, 455/67.6
• US Class Current: 370/242
• 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 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/203 Details of error rate determination, e.g. BER, FER or WER
• CPC Class Codes: H04L 2025/03764 only during predefined intervals
• CPC Class Codes: H04L 25/03159 operating in the frequency domain H04L25/03165, H04L25/03178 take precedence
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0042 intra-user or intra-terminal allocation
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/0058 Allocation criteria
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0085 when channel conditions change
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data

Abstract

A modem for use in Digital Subscriber Line communications transmits and receives data over the local subscriber loop in common with voice information over the loop, while avoiding the need for voice/data splitters. The modem responds to disruptions associated with “disturbance events” such as on-hook to off-hook transitions and the like by rapidly switching between pre-stored channel parameter control sets defining communications over the loop under varying conditions. In addition to changing parameter control sets responsive to a disturbance event, the modem may also change transmission power levels and other system parameters such as frequency domain equalizer characteristics. Further, provisions are made for reduced bandwidth communications under selected conditions.

Claims

1. In a multicarrier transmission system including a plurality of communication units communicating over a communications channel having a plurality of sub-channels, a method for communicating over the communications channel, comprising:

monitoring the communications channel to determine a current operating condition of the communications channel;

determining a power level for communicating on the communications channel based on the determined current operating condition of the communications channel;

establishing a plurality of tables; and

storing values for modulating data onto sub-channels of the communications channel into the plurality of tables, each table being associated with an operating condition of the communications channel and with a power level.

2. In a multicarrier transmission system including a plurality of communication units communicating over a communications channel having a plurality of sub-channels, a method for communicating over the communications channel, comprising:

monitoring the communications channel to determine a current operating condition of the communications channel;

determining a power level for communicating on the communications channel based on the determined current operating condition of the communications channel;

storing values for modulating data onto sub-channels of the communications channel into a plurality of tables, each table being associated with an operating condition of the communications channel and with a power level;

measuring at least one parameter indicative of the current operating condition of the communications channel; and

selecting one of the plurality of tables associated with the measured parameter for modulating data onto the sub-channels.

3. In a multicarrier transmission system including a plurality of communication units communicating over a communications channel having a plurality of sub-channels, a method for communicating over the communications channel, comprising:

determining a power level for transmitting from a first one of the communication units based on a current operating condition for the communications channel;

transmitting a signal indicating the determined power level to a second one of the communication units over the communications channel;

establishing a plurality of tables, and

storing values for modulating data onto sub-channels of the communications channel into the plurality of tables, each table being associated with an operating condition of the communications channel and with a power level.

4. In a multicarrier transmission system including a plurality of communication units communicating over a communications channel having a plurality of sub-channels, a method for communicating over the communications channel, comprising:

determining a power level for transmitting from a first one of the communication units based on a current operating condition for the communications channel;

transmitting a signal indicating the determined power level to a second one of the communication units over the communications channel;

storing values for modulating data onto sub-channels for the communications channel into a plurality of tables, each table being associated with an operating condition of the communications channel and with a power level;

measuring at least one parameter indicative of the current operating condition of the communications channel; and

selecting one of the plurality of tables associated with the measured parameter for modulating data onto the sub-channels.

5. A modem for communicating over a communications channel, comprising:

a monitor determining a current operating condition of the communications channel;

a control module choosing a power level for communicating on the communications channel based on the determined current operating condition of the communications channel;

a plurality of tables, each table having an operating condition identifier and a power level identifier; and

a transmitter modulating data onto sub-channels of the communications channel using the plurality of tables.

6. A modem for communicating over a communications channel, comprising:

a monitor determining a current operating condition of the communications channel;

a control module choosing a power level for communicating on the communications channel based on the determined current operating condition of the communications channel;

a plurality of tables, each table having an operating condition identifier and a power level identifier; and

a transmitter modulating data onto sub-channels of the communications channel using the plurality of tables,

wherein the monitor measures at least one parameter indicative of the current operating condition of the communications channel, and wherein the selector chooses the stored table associated with the measured parameter for modulating data onto the sub-channels.

7. A modem for communicating over a communications channel, comprising:

a control module choosing a power level for transmitting bits over the communications channel based on a current operating condition of the communications channel;

a transmitter sending a signal indicating the chosen power level to another modem over the communications channel; and

a plurality of tables, each table having an associated operating condition identifier and a power level identifier, and wherein the transmitter modulates data onto the sub-channels of the communications channel using the plurality of tables.

8. A modem for communicating over a communications channel, comprising:

a control module choosing a power level for transmitting bits over the communications channel based on a current operating condition of the communications channel;

a transmitter sending a signal indicating the chosen power level to another modem over the communications channel; and

a plurality of tables, each table having an associated operating condition identifier and a power level identifier, and wherein the transmitter modulates data onto the sub-channels of the communications channel using the plurality of tables,

wherein the monitor measures at least one parameter indicative of the current operating condition of the communications channel, and wherein the control module chooses one of the stored tables associated with the measured parameter for modulating data onto the sub-channels.