Method for transmitting user data in a multi-carrier radio communication system, and corresponding receiver

• US 7,742,534 B2
• Filed: 07/11/2006
• Issued: 06/22/2010
• Est. Priority Date: 08/01/2005
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Ballentin, Ralph, Kaminski, Stephen
• Primary Examiner(s): Ghebretinsae, Temesghen
• Application Number:
  US11/483,720
• Publication Number:
  US 20070025459A1
• Time in Patent Office: 1,442 Days
• Field of Search: 375/260, 375/316, 375/358, 455/450, 455/452, 455/452.1, 455/452.2
• US Class Current: 375/260
• CPC Class Codes: H04L 1/0021 in which the algorithm uses adaptive thresholds
• 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 5/0044 allocation of payload
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

The present invention relates to a method for transmitting user data between a transmitter and a receiver in a multi-carrier radio communication system having a plurality of orthogonal frequency sub-carriers, said method comprising the steps of selecting a set of sub-carriers on which said user data are to be transmitted between said transmitter and said receiver.

According to the present invention, the method comprises the steps of:

• • Sending from said transmitter, before transmission of said user data, an indication related to a threshold;
  • Determining at the receiver a quality level for each sub carriers;
  • Selecting at said receiver sub carriers to received said user data as a function of said indication related to a threshold and of said quality levels.

Claims

1. Method for transmitting user data between a transmitter and a receiver in a multi-carrier radio communication system having a plurality of orthogonal frequency sub-carriers, said method comprising the steps of

at the receiver, determining quality levels for said sub-carriers;

sending said quality levels from said receiver to said transmitter;

selecting, based on said quality levels, a set of sub-carriers on which said user data is to be transmitted between said transmitter and said receiver,

from said transmitter, before transmission of said user data, sending an indication related to a threshold, said indication and said quality levels enabling said receiver to deduce said set of sub-carriers on which said user data is to be transmitted; and

at said receiver, selecting said set of sub-carriers on which said user data is to be transmitted as a function of said indication and of said quality levels.

2. Method according to claim 1, wherein said function comprises the step of selecting said sub-carriers to receive said user data starting with the sub-carriers having the highest quality level and continuing with selecting the sub carrier with decreasing quality level until said threshold is reached.

3. Method according to claim 1, wherein said threshold is related to a quality level threshold.

4. Method according to claim 1, wherein said threshold is related to a maximal number of sub-carriers to be used.

5. Method according to claim 1, wherein quality levels are calculated at said receiver for groups of sub carriers.

6. An apparatus to facilitate communication of user data in a multi-carrier radio communication system having a plurality of orthogonal frequency sub-carriers, the apparatus comprising:

means for selecting a set of sub-carriers from the plurality of sub-carriers on which user data is to be communicated from a transmitter to a receiver, said selecting based at least in part on at least one of sub-carrier quality levels and a threshold indication associated with sub-carriers, said quality levels communicated from the receiver to the transmitter and said threshold indication communicated from the transmitter to the receiver;

said threshold indication and said quality levels enabling said receiver to deduce said set of sub-carriers on which said user data is to be communicated; and

a radio link for communicating user data via the selected set of sub-carriers;

wherein said receiver is adapted to receive user data from said transmitter via the radio link, said receiver comprising;

means for selecting said set of sub-carriers on which said user data is to be received from said transmitter;

means for determining quality levels for sub-carriers;

means for sending said quality levels to said transmitter; and

means for receiving and storing said threshold indication from said transmitter, said threshold indication and said quality levels enabling said receiver to deduce said set of sub-carriers on which said user data is to be received;

wherein said set of sub-carriers on which said user data is to be received are deduced as a function of said threshold indication and said quality levels.

7. The apparatus set forth in claim 6 wherein said threshold indication is one of a maximum number of sub-carriers in the set of sub-carriers and a minimum sub-carrier quality level for the set of sub-carriers.

8. The apparatus set forth in claim 6 wherein each sub-carrier quality level identifies at least one of a signal-to-interference ratio, a bit error rate, and a modulation scheme for a corresponding sub-carrier or a corresponding sub-carrier group.

9. The apparatus set forth in claim 6, the means for selecting said set of sub-carriers comprising:

means for selecting sub-carriers or sub-carrier groups with the highest quality level and decreasing quality levels until the threshold indication is reached.

10. The apparatus set forth in claim 6 wherein said threshold indication is received via at least one sub-carrier of the selected set of sub-carriers.

11. The apparatus set forth in claim 6, the means for receiving and storing said threshold indication comprising:

means for reading the threshold indication on at least one sub-carrier of the selected set of sub-carriers after detecting a specific identifier associated with the receiver on said at least one sub-carrier.

12. The apparatus set forth in claim 6, said receiver comprising a mobile terminal.

13. The apparatus set forth in claim 6, further comprising:

said transmitter adapted to transmit user data to said receiver via the radio link, said transmitter comprising;

means for selecting said set of sub-carriers on which said user data is to be transmitted to said receiver;

means for receiving said quality levels from said receiver; and

means for sending said threshold indication to said receiver, said threshold indication and said quality levels enabling said receiver to deduce the set of sub-carriers on which said user data is to be transmitted.

14. The apparatus set forth in claim 13 wherein said threshold indication is sent via at least one sub-carrier of the selected set of sub-carriers.

15. The apparatus set forth in claim 13, said transmitter comprising a base station.

16. A method of facilitating communication of user data in a multi-carrier radio communication system having a plurality of orthogonal frequency sub-carriers, comprising:

selecting a set of sub-carriers from the plurality of sub-carriers on which user data is to be communicated from a transmitter to a receiver, said selecting based at least in part on at least one of sub-carrier quality levels and a threshold indication associated with sub-carriers, said quality levels communicated from the receiver to the transmitter and said threshold indication communicated from the transmitter to the receiver, said threshold indication and said quality levels enabling said receiver to deduce said set of sub-carriers on which said user data is to be transmitted;

selecting said set of sub-carriers on which said user data is to be received from said transmitter at said receiver;

determining quality levels for sub-carriers at said receiver;

sending said quality levels from said receiver to said transmitter; and

receiving and storing said threshold indication from said transmitter at said receiver, said threshold indication and said quality levels enabling said receiver to deduce the set of sub-carriers on which said user data is to be received;

wherein said set of sub-carriers on which said user data is to be received are deduced as a function of said threshold indication and said quality levels.

17. The method set forth in claim 16, further comprising:

selecting said set of sub-carriers on which said user data is to be transmitted to said receiver at said transmitter;

receiving said quality levels from said receiver at said transmitter; and

means for sending the threshold indication from said transmitter to said receiver, said threshold indication and said quality levels enabling said receiver to deduce said set of sub-carriers on which said user data is to be transmitted.

18. The method set forth in claim 16, further comprising:

selecting said set of sub-carriers by selecting sub-carries or sub-carrier groups with the highest quality level and decreasing quality levels until the threshold indication is reached.