Dynamic link assignment in a communication system

• US 20020018527A1
• Filed: 07/16/2001
• Published: 02/14/2002
• Est. Priority Date: 07/24/2000
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Thesling, William H., Vanderaar, Mark J., Nimon, Matthew D.
• Granted Patent: US 7,230,908 B2
• Time in Patent Office: Days
• US Class Current: 375/259
• 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 of communicating data in a multi-user communication system, comprising the steps of:

providing channel information of a plurality of information channels in a communication link between a transmitter and one or more receiving devices;

varying said channel information in one or more of said plurality of information channels in response to associated link conditions between said transmitter and said corresponding receiving devices; and

transmitting said channel information with said transmitter to said corresponding receiving devices;

wherein said channel information is received by said respective receiving devices under substantially all link conditions.

2. The method of claim 1, wherein said plurality of information channels in the providing step are time division multiplexed.

3. The method of claim 1, wherein said channel information in said one or more of said plurality of information channels in the varying step is varied in modulation, coding, gain, and frequency in accordance with said link conditions of said corresponding receiving device.

4. The method of claim 1, wherein said channel information in said one or more of said plurality of information channels in the varying step is varied in modulation, coding, gain, and frequency in accordance with said link conditions associated with said corresponding receiving device such that synchronization of said respective information channel is maintained.

5. The method of claim 1, wherein synchronization of carrier and timing between said transmitter and said plurality of receiving devices is achieved utilizing a central channel of said plurality of information channels in said communication link.

6. The method of claim 5, wherein said central channel includes a plurality of information slots such that each said information slot must contain information in order to achieve said synchronization of carrier and timing.

7. The method of claim 1, wherein the communication system is a satellite communication system that transmits said channel information in said communication link that is a wireless forward communication link.

8. The method of claim 1, wherein said channel information of each said plurality of information channels in the providing step includes a unique ID, said unique ID for uniquely identifying each said receiving device.

9. The method of claim 8, wherein said unique ID is utilized to transmit said channel information in unicast to selects one of said plurality of receiving devices or in multicast to all said receiving devices.

10. The method of claim 1, wherein said channel information in the varying step is varied based upon the combination of modulation and coding in accordance with said link conditions of said corresponding information channel.

11. The method of claim 1, wherein the varying step is performed on select ones of said plurality of information channels utilizing time division multiplexing and orthogonal frequency division multiplexing.

13. The apparatus of claim 12, wherein said plurality of information channels are time division multiplexed.

14. The apparatus of claim 12, wherein said channel information is varied in modulation, coding, gain, and frequency in accordance with said link conditions of said corresponding receiving device.

15. The apparatus of claim 12, wherein said channel information is varied in modulation, coding, gain, and frequency in accordance with said link conditions associated with said corresponding receiving device such that synchronization of said respective information channel is maintained.

16. The apparatus of claim 12, wherein synchronization between said transmitter and said plurality of receiving devices is achieved utilizing a central channel of said plurality of information channels in said communication link.

17. The apparatus of claim 16, wherein said central channel includes a plurality of information slots such that each said information slot must contain information in order to achieve said synchronization, said synchronization including both carrier and timing.

18. The apparatus of claim 12, wherein the communication system is a satellite communication system that transmits said channel information in said communication link that is a wireless forward communication link.

19. The apparatus of claim 12, wherein said channel information of each said plurality of information channels includes a unique ID, said unique ID for uniquely identifying each said receiving device.

20. The apparatus of claim 19, wherein said unique ID is utilized to transmit said channel information in unicast to select ones of said plurality of receiving devices or in multicast to all said receiving devices.

21. The apparatus of claim 12, wherein said channel information is varied based upon the combination of modulation and coding in accordance with said link conditions of said corresponding information channel.

22. The apparatus of claim 12, wherein said channel information is varied on select ones of said plurality of information channels utilizing time division multiplexing and orthogonal frequency division multiplexing.

12. An apparatus for communicating data in a multi-user communication system, comprising:

a plurality of information channels in a communication link of the communication system for carrying channel between a transmitter and one or more receiving devices; and

a varying device for varying said channel information in one or more of said plurality of information channels in response to associated link conditions between said transmitter and said corresponding receiving devices;

wherein said channel information is transmitted with said transmitter to said corresponding receiving devices;

wherein said channel information is received by said respective receiving devices under substantially all link conditions.