Dynamic link assignment in a communication system

• US 7,684,368 B2
• Filed: 05/04/2007
• Issued: 03/23/2010
• Est. Priority Date: 07/24/2000
• Status: Expired due to Fees

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Thesling, William H., Nimon, Matthew D., Vanderaar, Mark J.
• Primary Examiner(s): Bost; Dwayne
• Assistant Examiner(s): Mehra; Inder P
• Application Number:
  US11/744,450
• Publication Number:
  US 20070208884A1
• Time in Patent Office: 1,054 Days
• Field of Search: 370/310, 370/322, 370/329, 370/342, 370/344, 370/347, 370/348, 370/436, 370/468, 370/337, 370/349, 370/504, 455/67.11, 455/504, 455/453
• US Class Current: 370/330
• 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 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/003 Arrangements for allocating sub-channels of the transmission path
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals

Abstract

An architecture for the dynamic assignment of links in a multi-user communication system. A plurality of information channels are provided in a forward communication link of the communication system for carrying channel information of the plurality of information channels from a transmitter to a plurality of corresponding receiving devices. The channel information in corresponding select ones of the plurality of information channels is varied dynamically in response to link conditions of the associated receiving devices to more efficiently utilize the channel bandwidth.

Claims

1. A method comprising:

dynamically assigning, to a receiving device, an available time slot in a first frequency channel of a broadcast communication signal including a plurality of frequency channels;

associating a unique ID with a first data packet to thereby identify the receiving device for the first data packet;

receiving information identifying a link condition for the receiving device;

dynamically assigning a modulation and coding format for the first data packet to account for the identified link condition;

generating a frame including;

a slot including a first field specifying the modulation and coding format and a second field identifying a next time slot in a subsequent frame for the receiving device to receive a subsequent data packet, wherein the subsequent frame may specify a new modulation and coding format for the receiving device; and

one or more additional slots including the first data packet and a second set of data packets destined for other users; and

transmitting the frame to the receiving device, wherein the first data packet is transmitted within the frame according to the modulation and coding format in the dynamically assigned time slot of the first frequency channel.

2. The method of claim 1, further comprising:

receiving information from the receiving device identifying a changed link condition for the receiving device; and

modifying the modulation and coding format for other data packets destined for the receiving device to account for the changed link condition.

3. The method of claim 2, further comprising:

assigning a second frequency channel to the receiving device for data packets transmitted using the modified modulation and coding format.

4. The method of claim 1, further comprising:

monitoring the link condition for the receiving device to determine that the link condition has changed for the receiving device; and

modifying the modulation and coding format for other data packets destined for the receiving device to account for the changed link condition.

5. The method of claim 1, further comprising:

transmitting data to the receiving device in a second frequency channel of the plurality of frequency channels identifying the dynamically assigned time slot.

6. The method of claim 1, further comprising:

transmitting data to the receiving device in a second frequency channel of the plurality of frequency channels identifying the first frequency channel assigned to the receiving device.

7. The method of claim 1, wherein the plurality of frequency channels comprise a plurality of sub-carriers in an orthogonal frequency division multiplexing (OFDM) communication link.

8. A method comprising:

transmitting data in a first frequency channel to a receiving device specifying a second frequency channel assigned to the receiving device, the second frequency channel comprising a frequency channel of a broadcast communication signal including a plurality of frequency channels;

associating a unique ID with a first data packet to thereby identify the receiving device for the first data packet;

receiving information identifying a link condition for the receiving device;

dynamically assigning a modulation and coding format for the first data packet to account for the identified link condition;

generating a frame including;

a slot including a first field specifying the modulation and coding format and a second field identifying a next time slot in a subsequent frame for the receiving device to receive a subsequent data packet, wherein the subsequent frame may specify a new modulation and coding format for the receiving device; and

one or more additional slots including the first data packet and a second set of data packets destined for other users; and

transmitting the frame in the second frequency channel to the receiving device, wherein the first data packet is transmitted within the frame according to the dynamically assigned modulation and coding format.

9. The method of claim 8, further comprising:

receiving information identifying a changed link condition for the receiving device; and

modifying the modulation and coding format for other data packets destined for the receiving device to account for the changed link condition.

10. The method of claim 8, further comprising:

dynamically assigning capacity in the second frequency channel to the receiving device.

11. The method of claim 8, further comprising:

assigning a time slot of a plurality of time slots in the second frequency channel to the receiving device.

12. A method comprising:

identifying a frequency channel with available capacity from among a plurality of frequency channels in a broadcast communication signal;

assigning the capacity in the identified frequency channel to a receiving device;

associating a unique ID with a first data packet to thereby identify the receiving device for the first data packet;

receiving information identifying a link condition for the receiving device;

dynamically assigning a modulation and coding format for the first data packet to account for the identified link condition;

generating a frame including;

a slot including a first field specifying the modulation and coding format and a second field identifying a next time slot in a subsequent frame for the receiving device to receive a subsequent data packet, wherein the subsequent frame may specify a new modulation and coding format for the receiving device; and

one or more additional slots including the first data packet and a second set of data packets destined for other users; and

transmitting the frame in the identified frequency channel to the receiving device, wherein the first data packet is transmitted within the frame according to the dynamically assigned modulation and coding format.

13. The method of claim 12, further comprising:

monitoring the link condition for the receiving device to determine that the link condition has changed for the receiving device; and

modifying the modulation and coding format for other data packets destined for the receiving device to account for the changed link condition.

14. The method of claim 12, wherein the assigning the capacity step comprises:

assigning to the receiving device a time slot of a plurality of available time slots in the identified frequency channel.

15. The method of claim 14, further comprising

assigning other time slots of the plurality of available time slots in the identified frequency channel to another receiving device.

16. The method of claim 14, further comprising:

transmitting data to the receiving device in a second frequency channel of the plurality of frequency channels, the data specifying the identified frequency channel.

17. The method of claim 14, further comprising:

transmitting data to the receiving device in a second frequency channel of the plurality of frequency channels, the data identifying a dynamically assigned time slot.

18. The method of claim 12, wherein the plurality of frequency channels comprise time division multiplexed channels in an orthogonal frequency division multiplexing (OFDM) communication link.

19. A device comprising:

a receiving unit configured to receive information identifying a link condition for the receiving device;

a processing unit configured to;

identify a frequency channel with available capacity from among a plurality of frequency channels in a broadcast communication signal;

assign the capacity in the identified frequency channel to a receiving device;

associate a unique ID with a first data packet to thereby identify the receiving device for the first data packet; and

dynamically assign a modulation and coding format for the first data packet to account for the identified link condition;

generate a frame including;

a slot including a first field specifying the modulation and coding format and a second field identifying a next time slot in a subsequent frame for the receiving device to receive a subsequent data packet, wherein the subsequent frame may specify a new modulation and coding format for the receiving device; and

one or more additional slots including the first data packet and a second set of data packets destined for other users; and

a transmitting unit configured to transmitting the frame in the identified frequency channel to the receiving device, wherein the first data packet is transmitted within the frame according to the dynamically assigned modulation and coding format.

20. The device of claim 19, wherein,

the receiving unit is further configured to receive information from the receiving device identifying a changed link condition for the receiving device;

and

the processing unit is further configured to assign a modified modulation and coding format for other data packets destined for the receiving device to account for the changed link condition.

21. The device of claim 19, wherein the transmitting unit is further configured to:

transmit data to the receiving device specifying assigned capacity in the identified frequency channel.

22. The device of claim 19, wherein the plurality of frequency channels comprise a plurality of carriers in a multicarrier communication link.

23. The device of claim 19, wherein the multicarrier communication link comprises an orthogonal frequency division multiplexing (OFDM) communication link.