METHOD AND SYSTEM FOR UPLINK MULTI-USER MULTIPLE-INPUT-MULTIPLE-OUTPUT COMMUNICATION IN WIRELESS NETWORKS

• US 20140119288A1
• Filed: 10/31/2012
• Published: 05/01/2014
• Est. Priority Date: 10/31/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Zhu, Chunhui, Kim, Youngsoo
• Granted Patent: US 9,232,502 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 74/0816 with collision avoidance

Abstract

Wireless communication in a wireless network comprises a wireless station obtaining a transmission opportunity period (TXOP) for communicating with an access point (AP) over a wireless communication channel. The wireless station sends an announcement to the AP to share the transmission opportunity period with at least another wireless station, as a multi-user transmission opportunity period for simultaneously transmitting data from said wireless stations to the AP on multiple uplink (UL) spatial streams over the wireless channel.

Claims

1. A method of wireless communication, comprising:

a wireless station obtaining a transmission opportunity period (TXOP) for communicating with an access point (AP) over a wireless communication channel; and

the wireless station sending an announcement to the AP to share the transmission opportunity period with at least another wireless station, as a multi-user transmission opportunity period for simultaneously transmitting data from said wireless stations to the AP on multiple uplink (UL) spatial streams over the wireless channel.

2. The method of claim 1, wherein:

transmitting said announcement comprises transmitting an uplink transmission request (UTR).

3. The method of claim 2, further comprising:

in response to the UTR, the AP determines one or more target wireless stations allowed to transmit to the AP in an uplink phase of the transmission opportunity period.

4. The method of claim 3, further comprising:

the AP transmits an uplink transmission indication (UTI) frame to all target wireless stations along with addresses of target wireless stations allowed to transmit in the AP in the uplink phase, and the allowed uplink transmission time for each target wireless station.

5. The method of claim 4, further comprising:

in response to receiving a UTI from the AP, each target wireless station initiating uplink transmissions to the AP during the uplink phase.

6. The method of claim 5, further comprising:

synchronizing the uplink transmissions of data frames from the target wireless stations such that the AP can correctly decode the data carried in the uplink transmissions belonging to each target wireless station.

7. The method of claim 6, wherein the uplink transmission comprises uplink multi-user multiple-input-multiple-output (UL MU-MIMO) communication from the target wireless stations to the AP.

8. The method of claim 7, further comprising:

uplink data transmission in a wireless network comprising a wireless local area network (WLAN), wherein the data frames are organized into access categories in order of transmission priority; and

contending for channel access by performing Enhanced Distributed Channel Access (EDCA) to provide Quality of Service (QoS) for a data frame in a high priority access category.

9. The method of claim 7, further comprising:

the AP performing downlink transmission of an acknowledgment to the each wireless station in response to one or more uplink data frames.

10. The method of claim 2, wherein transmitting a UTR comprises:

transmitting an enhanced RTS frame with an indication bit set in the Frame Control field of the MAC header of the enhanced RTS frame, to indicate a UTR function.

11. The method of claim 2, wherein transmitting a UTR comprises:

transmitting an enhanced RTS frame with an indication bit set in the Service field of the enhanced RTS frame, to indicate a UTR function for sharing the TXOP to allow simultaneously transmitting data from multiple wireless stations to the AP on multiple uplink (UL) spatial streams over the wireless channel.

12. The method of claim 2, wherein transmitting a UTR comprises:

transmitting an enhanced RTS frame with an indication bit set in the preamble of the enhanced RTS frame, to indicate a UTR function.

13. The method of claim 2, wherein transmitting a UTR comprises:

transmitting an enhanced RTS frame with a ultra high throughput (UHT) Control Wrapper indicating a UTR function.

14. The method of claim 2, wherein transmitting a UTR comprises transmitting a UTR control frame, the UTR control from comprising:

a Duration/ID field indicating a requested TXOP duration and any control overhead;

a receiver address (RA) field including the MAC address of the AP;

a Transmitter Address (TA) field including the MAC address of the wireless station owner of the TXOP; and

an Access Category (AC) field in the frame body indicating the AC that obtains a TXOP.

15. The method of claim 4, wherein transmitting a UTI comprises:

in response to an enhanced RTS frame indicating a UTR, the AP transmitting an enhanced CTS frame with a conventional RA field of the CTS frame replaced with a compressed RA field to represent multiple wireless stations, and an indication subfield set to indicate a UTI function.

16. The method of claim 4, wherein transmitting a UTI comprises:

in response to an enhanced RTS frame indicating a UTR, the AP transmitting conventional CTS frame followed by a CF-Multi-Poll frame which contains the MAC addresses of target wireless stations for uplink transmission.

17. The method of claim 4, wherein transmitting a UTI comprises:

in response to an enhanced RTS frame indicating a UTR, the AP transmitting a CF-Multi-Poll frame only.

18. The method of claim 4, wherein transmitting a UTI comprises:

in response to enhanced RTS frame with a UHT Control Wrapper indicating a UTR function, the AP transmitting an enhanced CTS frame with a UHT Control Wrapper indicating a UTI function.

19. The method of claim 4, wherein transmitting a UTI comprises, in response to a UTR control frame, the AP transmitting a UTI control frame including:

a Duration/ID field indicating a granted TXOP duration for uplink transmission and any control overhead;

an RA field containing the MAC address of the UTR sender;

a Number of STA Addresses Present field indicating the number of wireless station (STA) addresses to be presented in a List of STA Addresses field; and

a List of STA Addresses field containing the MAC addresses of the target wireless stations.

20. The method of claim 10, wherein the enhanced RTS frame further includes information for a wireless station to distinguish the enhanced RTS frame from a legacy RTS frame.

21. The method of claim 15, wherein the enhanced CTS frame further includes information for a wireless station to distinguish the enhanced CTS frame from a legacy CTS frame.

22. A wireless station, comprising:

a Physical Layer (PHY) for wireless communication over a wireless communication channel;

Media Access Control (MAC) layer; and

a channel access module that obtains a transmission opportunity period (TXOP) for communicating with an access point (AP) over a wireless communication channel, wherein the channel access module sends an announcement to the AP to share the transmission opportunity period with at least another wireless station as a multi-user transmission opportunity period for simultaneously transmitting data from said wireless stations to the AP on multiple uplink (UL) spatial streams over the wireless channel.

23. The wireless station of claim 22, wherein:

the channel access module transmits said announcement as an uplink transmission request (UTR) to the AP, the announcement including an enhanced RTS frame with an indication bit set in the Frame Control field of the MAC header of the enhanced RTS frame, to indicate a UTR function for simultaneously transmitting data from multiple wireless stations to the AP on multiple uplink (UL) spatial streams over the wireless channel.

24. The wireless station of claim 22, wherein:

the channel access module transmits said announcement as an uplink transmission request (UTR) to the AP, the announcement including an enhanced RTS frame with an indication bit set in the Service field of the enhanced RTS frame, to indicate a UTR function.

25. The wireless station of claim 22, wherein:

the channel access module transmits said announcement as an uplink transmission request (UTR) to the AP, the announcement including an enhanced RTS frame with an indication bit set in the preamble of the enhanced RTS frame, to indicate a UTR function.

26. The wireless station of claim 22, wherein:

the channel access module transmits said announcement as an uplink transmission request (UTR) to the AP, the announcement including an enhanced RTS frame with a ultra high throughput (UHT) Control Wrapper indicating a UTR function.

27. The wireless station of claim 22, wherein:

the channel access module transmits said announcement as an uplink transmission request (UTR) to the AP, the announcement including;

a Duration/ID field indicating a requested TXOP duration and any control overhead;

a receiver address (RA) field including the MAC address of the AP;

a transmitter address (TA) field including the MAC address of the wireless station owner of the TXOP; and

an access category (AC) field in the frame body indicating the AC that obtains a TXOP.

28. A wireless access point, comprising:

a Physical Layer (PHY) for wireless communication over a wireless communication channel; and

Media Access Control (MAC) layer that manages simultaneous transmissions from multiple wireless stations to the access point on multiple uplink (UL) spatial streams during a multi-user transmission opportunity period over a wireless channel.

29. The wireless access point of claim 28, further comprising:

a channel access module that received an announcement as an uplink transmission request (UTR) from a wireless station to share a transmission opportunity period with at least another wireless station as a multi-user transmission opportunity period for simultaneously transmitting data from said wireless stations to the access point (AP) on multiple uplink (UL) spatial streams over the wireless channel;

wherein in response to the UTR, the access module of, the AP determines one or more target wireless stations allowed to transmit to the AP in an uplink phase of the transmission opportunity period.

30. The wireless access point of claim 29, wherein the access module transmits an uplink transmission indication (UTI) frame to all target wireless stations along with addresses of target wireless stations allowed to transmit in the AP in the uplink phase, and the allowed uplink transmission time for each target wireless station.

31. The wireless access point of claim 30, wherein the uplink transmission comprises uplink multi-user multiple-input-multiple-output (UL MU-MIMO) communication from the target wireless stations to the AP.

32. The wireless access point of claim 31, wherein the access module transmits an acknowledgment to the each wireless station in response to one or more uplink data frames.

33. The wireless access point of claim 30, wherein the access module transmits a UTI in response to an enhanced RTS frame from a wireless station indicating a UTR, the UTI comprising an enhanced CTS frame with a conventional RA field of the CTS frame replaced with a compressed RA field to represent multiple wireless stations, and an indication subfield set to indicate a UTI function.

34. The wireless access point of claim 30, wherein the access module transmits a UTI in response to an enhanced RTS frame indicating a UTR, the UTI comprising a conventional CTS frame followed by a CF-Multi-Poll frame which contains the MAC addresses of target wireless stations for uplink transmission.

35. The wireless access point of claim 30, wherein the access module transmits a UTI in response an enhanced RTS frame indicating a UTR, wherein the UTI comprises a CF-Multi-Poll frame only.

36. The wireless access point of claim 30, wherein the access module transmits a UTI in response to enhanced RTS frame with a UHT Control Wrapper indicating a UTR function, the UTI comprising an enhanced CTS frame with a UHT Control Wrapper indicating a UTI function.

37. The wireless access point of claim 30, wherein the UTI comprises a UTI control frame including:

a Duration/ID field indicating a granted TXOP duration for uplink transmission and any control overhead;

an RA field containing the MAC address of the UTR sender;

a Number of STA Addresses Present field indicating the number of wireless station a addresses to be presented in a List of STA Addresses field; and

a List of STA Addresses field containing the MAC addresses of the target wireless stations.