Downstream adaptive modulation in broadband communications system

• US 20070037531A1
• Filed: 10/19/2006
• Published: 02/15/2007
• Est. Priority Date: 03/15/2002
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Dale, Mark, Hebsgaard, Anders, Hartman, David
• Granted Patent: US 7,778,592 B2
• Time in Patent Office: Days
• US Class Current: 455/102
• CPC Class Codes: H04J 3/04 Distributors combined with modulators or demodulators pulse distributors in general H03K5/15; pulse counters H03K21/00 - H03K29/06; for telegraphy H04L5/22, H04L13/00 - H04L23/00, H04L25/45; for telephony H04Q11/04
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 27/2604 Multiresolution systems by means of multiresolution subcarriers H04L27/183, H04L27/3488

Abstract

A downstream adaptive modulation system and method. The downstream adaptive modulation system comprises a wireless access termination system and one or more wireless modems. The wireless access termination system includes a plurality of queues and a parser. The parser parses data traffic onto the plurality of queues. Each queue is associated with a different coding and modulation scheme. Each of the one or more wireless modems receives data traffic from the plurality of queues based on the wireless modem'"'"'s ability to demodulate and decode the signal from each of the plurality of queues. When a wireless modem experiences a change in signal strength, the present invention enables the wireless modem to adapt to data from other queues to compensate for the change in signal strength. Thus, if the signal strength improves over a period of time, the wireless modem may receive data at a higher order modulation and FEC code rate. If the signal strength weakens over a period of time, the wireless modem may receive data at a lower order modulation and FEC code rate.

Claims

1. An adaptive modulation transmitter, comprising:

a parser to parse a data stream into a plurality of queues;

an encoder to encode the data in each of the plurality of queues, wherein the encoder is configured to encode the queues with at least two different modulation schemes;

a summer to combine the data from each queue into a frequency channel; and

an antenna to transmit the frequency channel storing the combined data.

2. The transmitter of claim 1, wherein the encoder encodes each queue with a different modulation scheme.

3. The transmitter of claim 1, wherein the data from each queue is combined in an order according to the modulation scheme of each queue.

4. An adaptive modulation system, comprising:

a parser to parse a data stream into a first queue and a second queue;

an encoder to encode the data in the first queue with a first modulation scheme and data in the second queue with a second modulation scheme;

a summer to combine the data from the first and second queues into a data channel; and

an antenna to transmit the data channel storing the combined data.

5. The system of claim 4, wherein the data from each queue is combined in an order according to the modulation scheme of each queue.

6. The system of claim 4, further comprising:

a plurality of receivers for receiving the transmitted data channel, wherein each receiver comprises;

a splitter to split power levels of the data channel into a plurality of queues, each queue is associated with a different modulation order, wherein the receiver is configured to decode data from each queue based on its ability to demodulate the data in each queue.

7. An adaptive modulation receiver, comprising:

an antenna for receiving a data stream on a data channel;

a splitter to split power levels of the data channel into a plurality of queues, each queue is associated with a different modulation order, wherein the receiver is configured to decode data from each queue based on its ability to demodulate the data in each queue.

8. The system of claim 7, wherein the receiver further comprises:

a multiplexer for selecting data from the plurality of queues that the receiver is capable of demodulating.