Method of communications between MIMO stations

• US 20050160181A1
• Filed: 01/11/2005
• Published: 07/21/2005
• Est. Priority Date: 01/15/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Yang, Chil-youl, Kim, Tae-kon, Kwon, Chang-yeul
• Granted Patent: US 7,489,652 B2
• Time in Patent Office: Days
• US Class Current: 709/238
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Provided is a link adaptation method for a multi input multi output (MIMO) system having a multi-antenna structure and a communicating method of MIMO stations in a basic service set (BSS), which constitutes a wireless communication network. The communicating method includes receiving the number of MIMO antennas and transmission rates supported by the respective MIMO antennas from a predetermined MIMO station, storing one or more channel estimation indicators obtained while receiving various frames from the predetermined MIMO station for each MIMO antenna and for each transmission rate supported by the MIMO antenna, determining threshold levels of the channel estimation indicators for each MIMO antenna, comparing threshold levels of channel estimation indicators for each MIMO antenna with an average of channel estimation indicators for each MIMO antenna, and determining a transmission rate based on comparison results to then transmit data to the predetermined MIMO station at the determined transmission rate.

Claims

1. A link adaptation method for a wireless communication network using at least one antenna configured to transmit and receive, the link adaptation method comprising:

generating information on a management frame, the information on the management frame comprises single input single output (SISO) information that indicates at least one transmission rate of a first plurality of transmission rates supported by a single SISO antenna configured to transmit and receive,

and multi input multi output (MIMO) information that indicates at least one transmission rate of a second plurality of transmission rates supported by a plurality of MIMO antennas configured to transmit and receive; and

transmitting the information on the management frame using either the single SISO antenna or at least one of the plurality of MIMO antennas.

2. The link adaptation method of claim 1, wherein the management frame comprises at least one of a beacon frame, an association request frame, a dissociation frame, an association response frame, a probe request frame, and a probe response frame.

3. The link adaptation method of claim 1, wherein the MIMO information comprises a number corresponding to a number of MIMO antennas and includes data corresponding to the at least one transmission rate of the second plurality of transmission rates supported by at least one of the plurality of MIMO antennas.

4. A link adaptation method for a wireless communication network using at least one antenna configured to transmit and receive, the link adaptation method comprising:

receiving information on a management frame, the information on the management frame comprises single input single output (SISO) information that indicates at least one transmission rate of a first plurality of transmission rates supported by a single SISO antenna configured to transmit and receive,

and multi input multi output (MIMO) information that indicates at least one transmission rate of a second plurality of transmission rates supported by a plurality of MIMO antennas configured to transmit and receive; and

generating a channel estimation table using the information on the management frame.

5. The link adaptation method of claim 4, wherein the management frame comprises at least one of a beacon frame, an association request frame, a dissociation frame, an association response frame, a probe request frame, and a probe response frame.

6. The link adaptation method of claim 4, wherein the MIMO information comprises a number corresponding to a number of MIMO antennas and includes data corresponding to the at least one transmission rate of the second plurality of transmission rates supported by at least one of the plurality of MIMO antennas.

7. The link adaptation method of claim 4, wherein the channel estimation table includes a received signal strength indicator (RSSI).

14. The link adaptation method of claim 4, wherein the channel estimation table includes at least an average packet error rate (PER).

15. The link adaptation method of claim 4, wherein the channel estimation table includes at least an average number of retries of data transmission until an acknowledgement (ACK) frame is received.

8. A communicating method of MIMO stations in a basic service set (BSS), which constitutes a wireless communication network, the communicating method comprising:

receiving data which identifies a number of MIMO antennas and specifies at least one transmission rate of a plurality of transmission rates supported by respective ones of the MIMO antennas, the data being transmitted from a predetermined MIMO station;

storing at least one channel estimation indicator obtained while receiving at least one frame from the predetermined MIMO station for the respective ones of the MIMO antennas and for the respective transmission rates supported by the MIMO antennas;

determining a threshold level of the at least one channel estimation indicator for the respective ones of the MIMO antennas;

comparing the threshold level of the at least one channel estimation indicator for the respective ones of the MIMO antennas with averages of the at least one channel estimation indicator for the respective ones of the MIMO antennas; and

determining a transmission rate based on a comparison result to then transmit data to the predetermined MIMO station at a determined transmission rate.

9. The communicating method of claim 8, wherein the determining of a transmission rate comprises:

determining, for each of the MIMO antennas, a highest transmission rate for which the average of the at least one channel estimation indicator stored for each of the MIMO antennas respectively exceeds the threshold level of the at least one channel estimation indicator;

summing up the highest transmission rates determined for each of the MIMO antennas to obtain a summing result;

obtaining another summing result by performing, for another station, the step of receiving data, the step of storing at least one channel estimation indicator, the step of determining a threshold level of the at least one channel estimation indicator, the step of comparing the threshold level of the at least one channel estimation indicator, the step of determining, for each of the MIMO antennas, a highest transmission rate, and the step of summing up the highest transmission rates, determined with respect to the another station; and

selecting a lower of the summing result and the another summing result as a transmission rate for transmitting data to the predetermined MIMO station at the selected transmission rate.

10. The communicating method of claim 8, wherein a channel estimation table includes a received signal strength indicator (RSSI) defined by the IEEE 802.11 standard.

11. The communicating method of claim 10, wherein the channel estimation table further includes an average packet error rate (PER).

12. The communicating method of claim 10, wherein the channel estimation table further includes an average number of retries of data transmission until an acknowledgement (ACK) frame is received.

13. The communicating method of claim 10, wherein the RSSI corresponds to a measured value of the respective ones of the MIMO antennas which is converted into vectors and is transmitted to a MAC layer and stored in the channel estimation table.