# US 2014/0153522 A1 · Method and System for Link Adaptation at a Mobile Station

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2014/0153522 A1
- Document ID: US20140153522A1
- Status: Published application
- Kind: A1
- Application number: 14/173,098
- Filed: 2014-02-05
- Published: 2014-06-05
- Earliest claimed: 2007-05-04
- Assignees: Motorola Mobility LLC
- Applicants: Motorola Mobility LLC
- Inventors: Krishna Kamal Sayana; Xiangyang Zhuang
- Web page: https://patentgrep.com/patent/US20140153522A1

## CPC

- H04W 72/21: in the uplink direction of a wireless link, i.e. towards the network
- H04B 7/0417: Feedback systems
- H04B 7/0617: {for beam forming}
- H04L 1/0003: {by switching between different modulation schemes}
- H04L 1/0025: {Transmission of mode-switching indication}
- H04L 1/0028: {Formatting}
- H04L 1/0035: {evaluation of received explicit signalling}
- H04L 1/06: using space diversity
- H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ]
- H04W 88/02: Terminal devices
- H04W 88/08: Access point devices
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04B: TRANSMISSION
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A method for link adaptation at a mobile station (120) can include the steps of computing (220) 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 (245) the feedback information to a base station.

## Claims

### Claim 1

A method for link adaptation at a mobile station, comprising:
for each candidate modulation type of a plurality of candidate modulation types, computing a mutual information per coded bit (MIB) metric for at least one sub-channel of each candidate modulation type, wherein the MIB metric is the mutual information between each coded bit and a log-likelihood radio of that bit based on a receiver type and a signal-to-noise and interference ratio of the sub-channel;
averaging the MIB metrics over the at least one sub-channel of each candidate modulation type to produce a mean MIB (MMIB) metric for each candidate modulation type;
generating feedback information, wherein the feedback information includes the MMIB metric for each of the plurality of candidate modulation types; and
transmitting the feedback information to a base station.

### Claim 2 (depends on 1)

The method according to claim 1 wherein the computing a mutual information per coded bit (MIB) metric comprises:
using eigenvalues of a MIMO transmission with the base station.

### Claim 3 (depends on 1)

The method according to claim 1 wherein the computing a mutual information per coded bit (MIB) metric comprises:
using eigen-subspace powers of a MIMO transmission with the base station.

### Claim 4 (depends on 1)

The method according to claim 1 wherein the computing a mutual information per coded bit (MIB) metric comprises:
using a condition number of a channel state matrix of a MIMO transmission with the base station.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the generating feedback information comprises:
mapping each MMIB metric to an index based on a predetermined table known to both the mobile station and the base station.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the generating feedback information comprises:
including a recommended setting for one or more MIMO transmission parameters.

### Claim 7 (depends on 1)

The method according to claim 1, wherein the generating feedback information comprises:
including a recommended MIMO transmission mode.

### Claim 8 (depends on 7)

The method according to claim 7, wherein the recommended MIMO transmission mode comprises:
including an open loop MIMO transmission scheme recommendation.

### Claim 9 (depends on 7)

The method according to claim 7, wherein the recommended MIMO transmission mode comprises:
including a closed loop MIMO transmission scheme recommendation.

### Claim 10 (depends on 7)

The method according to claim 7, wherein the recommended MIMO transmission mode comprises:
including a number of coding layers recommendation.

### Claim 11 (depends on 7)

The method according to claim 7, wherein the recommended MIMO transmission mode comprises:
including a number of symbol streams recommendation.

### Claim 11 (depends on 7)

The method according to claim 7, wherein the recommended MIMO transmission mode comprises:
including an antenna beamforming weights vector recommendation.

### Claim 12 (depends on 1)

The method according to claim 1 wherein the transmitting is in response to a request from the base station.