LINK ADAPTATION AND DEVICE IN ACTIVE SCANNING METHOD

• US 20140247746A1
• Filed: 10/22/2012
• Published: 09/04/2014
• Est. Priority Date: 11/07/2011
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: You, Hyang Sun, Seok, Yong Ho, Park, Jong Hyun
• Granted Patent: US 9,781,615 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 24/06 Testing, supervising or monitoring using simulated traffic
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information

Abstract

Disclosed are a link adaptation method and device in an active scanning method. The link adaptation method transmits a the probe request frame comprising null data packet announcement (NDPA) information elements, transmits a null data packet (NDP) frame comprising only a physical layer convergence protocol (PLCP) header after transmitting the probe request frame, and receives a the probe response frame comprising feedback information elements measured based on the NDP frame. Therefore, the invention is capable of improving data transmission efficiency by using a modulation coding scheme (MCS) suitable for a channel state from initial connection.

Claims

1. A method for link adaptation, the link adaptation comprising:

transmitting a probe request frame including a Null Data Packet Announcement (NDPA) information element;

transmitting a Null Data Packet (NDP) frame including only a Physical Layer Convergence Protocol (PLCP) header after transmitting the probe request frame; and

receiving a probe response frame including a feedback information element determined based on the NDP frame,

wherein the NDPA information element includes NDP information indicating whether or not the probe request frame is used as the NDPA frame, and

the feedback information element includes at least one of Modulation and Coding Scheme (MCS) feedback information and sounding feedback information.

2. The method of claim 1, further comprising:

receiving the NDP frame after receiving the probe response frame if the probe response frame includes the NDPA information element; and

transmitting an authentication request frame including the feedback information element based on the NDP frame,

wherein the feedback information element includes at least one of the MCS feedback information and the sounding feedback information.

3. The method of claim 1,

wherein the NDPA information element further includes a feedback type, beamforming, and an Nc index,

the feedback type is an indicator indicating whether the feedback information is transmitted to a single user or transmitted to multiple users,

the beamforming is an indicator indicating whether or not beamforming is performed, and

the Nc index is an indicator indicative of a feedback dimension required when the beamforming is used.

4. The method of claim 1,

wherein the MCS feedback information includes a number of spatial streams and an MCS index,

the number of spatial streams is an indicator indicating a number of spatial streams used in transmission, and

the MCS index is an indicator indicating an modulation and coding scheme used in transmission.

5. The method of claim 1,

wherein the sounding feedback information comprises a compressed beamforming report, and

wherein the compressed beamforming report comprises a Signal to Noise Ratio (SNR) of each spatial stream and at least one beamforming matrix.

6. The method of claim 1, further comprising:

transmitting an authentication request frame according to a Multiple Input Multiple Output (MIMO) transmission method using beamforming based on the MCS feedback information.

7. A wireless terminal performing link adaptation, the wireless terminal comprising:

a transceiver configured to;

transmit a probe request frame including a Null Data Packet Announcement (NDPA) information element;

transmit a Null Data Packet (NDP) frame including only a Physical Layer Convergence Protocol (PLCP) header after transmitting the probe request frame; and

receive a probe response frame including a feedback information element determined based on the NDP frame,

wherein the NDPA information element comprises NDP information indicating whether or not the probe request frame is used as the NDPA frame, and

the feedback information element includes at least one of Modulation and Coding Scheme (MCS) feedback information and sounding feedback information.

8. The wireless terminal of claim 7,

wherein the transceiver is configured to:

receive the NDP frame after receiving the probe response frame if the probe response frame includes the NDPA information element; and

transmit an authentication request frame including the feedback information element based on the NDP frame,

wherein the feedback information element includes at least one of the MCS feedback information and the sounding feedback information.

9. The wireless terminal of claim 7,

wherein the NDPA information element further includes a feedback type, beamforming, and an Nc index,

the feedback type is an indicator indicating whether the feedback information is transmitted to a single user or transmitted to multiple users,

the beamforming is an indicator indicating whether or not beamforming is performed, and

the Nc index is an indicator indicative of a feedback dimension required when the beamforming is used.

10. The wireless terminal of claim 7,

wherein the MCS feedback information includes a number of spatial streams and an MCS index,

the number of spatial streams is an indicator indicating a number of spatial streams used in transmission, and

the MCS index is an indicator indicating an modulation and coding scheme used in transmission.

11. The wireless terminal of claim 7,

wherein the sounding feedback information includes a compressed beamforming report, and

the compressed beamforming report comprises a Signal to Noise Ratio (SNR) of each spatial stream and at least one beamforming matrix.

12. The wireless terminal of claim 7,

wherein the transceiver is configured to transmit an authentication request frame according to a Multiple Input Multiple Output (MIMO) transmission method using beamforming based on the MCS feedback information.