Method and system for link adaptation at a mobile station

• US 9,844,038 B2
• Filed: 07/28/2015
• Issued: 12/12/2017
• Est. Priority Date: 05/04/2007
• Status: Expired due to Fees

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Inventors: Sayana, Krishna Kamal, Zhuang, Xiangyang
• Primary Examiner(s): Patel, Chandrahas
• Application Number:
  US14/811,146
• Publication Number:
  US 20160029372A1
• Time in Patent Office: 868 Days
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0028 Formatting
• CPC Class Codes: H04L 1/0035 evaluation of received explicit signalling
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A method for link adaptation at a mobile station can include the steps of computing mutual information per coded bit (MIB) metrics on at least one sub-channel for one or more candidate modulation types. The method may average the MIB metrics over at least two sub-channels, generate feedback information including MIB metrics for the plurality of candidate modulation types, and transmit the feedback information to a base station.

Claims

1. A method for link adaptation at a mobile station, comprising:

receiving a request from a base station for feedback information including at least one of a modulation type selected at the mobile station and information for selection of a modulation type at the base station;

generating the requested feedback information, including generating a mutual information per coded bit (MIB) metric for each of a plurality of candidate modulation types, the MIB metric being mutual information between a given coded bit and a log-likelihood ratio of the given coded bit; and

transmitting, in response to the request, the generated feedback.

2. The method according to claim 1, further comprising computing the MIB metrics

using at least one of eigenvalues, eigen-subspace powers, and a condition number of a channel state matrix of a MIMO transmission with the base station.

3. The method according to claim 1, wherein the MIB metric is based on a receiver type.

4. The method according to claim 1, wherein the MIB metric is based on a channel state knowledge of one or more sub-channels including signal-to-noise and interference ratio of the sub-channel.

5. The method according to claim 1, wherein the generating the requested feedback information comprises:

mapping each MIB metric to an index based on a predetermined table known to both the mobile station and the base station.

6. The method according to claim 1, wherein the MIB metric for a given candidate modulation type is computed for at least one sub-channel of the given candidate modulation type.

7. The method according to claim 1, wherein the generating the requested feedback information comprises:

including at least one of a recommended MIMO transmission mode and a recommended setting for one or more MIMO transmission parameters.

8. The method according to claim 7, wherein the recommended MIMO transmission mode comprises:

including an open loop MIMO transmission scheme recommendation.

9. The method according to claim 7, wherein the recommended MIMO transmission mode comprises:

including a closed loop MIMO transmission scheme recommendation.

10. The method according to claim 7, wherein the recommended MIMO transmission mode comprises:

including a number of coding layers recommendation.

11. The method according to claim 7, wherein the recommended MIMO transmission mode comprises:

including a number of symbol streams recommendation.

12. The method according to claim 7, wherein the recommended MIMO transmission mode comprises:

including an antenna beamforming weights vector recommendation.

13. A system comprising:

one or more processors configured to;

receiving a request from a base station for feedback information including at least one of a modulation type selected at the mobile station and information for selection of a modulation type at the base station;

generate the requested feedback information, including generating a mutual information per coded bit (MIB) metric for each of a plurality of candidate modulation types, the MIB metric being mutual information between a given coded bit and a log-likelihood ratio of the given coded bit; and

transmit, using the transceiver, in response to the request, the generated feedback information to the base station.

14. The system according to claim 13, wherein the one or more processors are further configured to compute the MIB metrics using eigenvalues of a MIMO transmission with the base station.

15. The system according to claim 13, wherein the one or more processors are further configured to compute the MIB metrics using eigen-subspace powers of a MIMO transmission with the base station.

16. The system according to claim 13, wherein the one or more processors are further configured to compute the MIB metrics using a condition number of a channel state matrix of a MIMO transmission with the base station.

17. The system according to claim 13, wherein the generating the requested feedback information comprises:

mapping each MIB metric to an index based on a predetermined table known to both the mobile station and the base station.

18. The system according to claim 13, wherein the generating the requested feedback information comprises:

including at least one of a recommended setting for one or more MIMO transmission parameters and a recommended MIMO transmission mode.

19. A mobile station comprising one or more processors, the one or more processors configured to:

receive a request from a base station for feedback information including at least one of a modulation type selected at the mobile station and information for selection of a modulation type at the base station;

generate the requested feedback information, including generating a mutual information per coded bit (MIB) metric for each of a plurality of candidate modulation types, the MIB metric being mutual information between a given coded bit and a log-likelihood ratio of the given coded bit; and

transmit, in response to the request, the generated feedback information to the base station.