Systems and methods for multi-user simultaneous transmissions

• US 9,408,184 B2
• Filed: 08/14/2015
• Issued: 08/02/2016
• Est. Priority Date: 08/01/2014
• Status: Active Grant

• Current Assignee: Atlas Global Technologies LLC (Acacia Research Corporation)
• Original Assignee: Newracom Inc.
• Inventors: Hedayat, Ahmad Reza, Kwon, Young Hoon
• Primary Examiner(s): Phillips, Hassan
• Assistant Examiner(s): JONES, PRENELL P
• Application Number:
  US14/827,224
• Publication Number:
  US 20160037484A1
• Time in Patent Office: 354 Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Systems, methods, and devices are provided for protecting a multiuser (MU) transmission between an access point and a plurality of wireless stations. The access point may transmit a frame that is addressed to multiple stations in a wireless network. Each of the stations addressed by the frame may respond with an identical clear-to-send frame. In some instances, the clear-to-send frames transmitted by each wireless station may utilize the same scrambling code utilized by the frame transmitted by the access point, use the same modulation and coding scheme, and/or occupy the same frequency bands such that the multiple clear-to-send frames are combined in the air and detected as a single frame by the access point. In some instances, the access point may thereafter transmit an uplink reference frame to trigger the wireless stations to transmit an uplink data request frame to the access point.

Claims

1. A method for performing communications in a wireless system, the method comprising:

processing, by a first wireless station in the wireless system, a first frame that is transmitted from an access point and is addressed to the first wireless station and a second wireless station in the wireless system; and

transmitting, by the first wireless station, a second frame to the access point in response to the first frame, wherein the second frame is identical to a third frame simultaneously transmitted by the second wireless station to the access point in response to the first frame,

wherein the first frame requests use of a shared wireless channel, upon which the first frame is transmitted, for use in multiuser communications and provides implicit timing information for transmitting the second and third frames, and

wherein the second frame provides clearance from the first wireless station to utilize the shared wireless medium, the second frame is transmitted on the same sub-bands as the third frame, and the second and third frames are Clear-To-Send (CTS) frames.

2. The method of claim 1, further comprising:

generating, by the first wireless station, the second frame using a scrambling code, wherein the second wireless station uses the scrambling code to generate the third frame.

3. The method of claim 2, wherein the scrambling code is the same scrambling code used by the access point to generate the first frame.

4. The method of claim 2, wherein the scrambling code is predetermined prior to the first wireless station generating the second frame.

5. The method of claim 1, further comprising:

processing, by the first wireless station, a fourth frame that is received from the access point after transmission of the second frame; and

transmitting, by the first wireless station, a fifth frame to the access point, wherein the fifth frame is transmitted in a multiuser uplink transmission that is triggered by the fourth frame.

6. The method of claim 5, wherein the fourth frame is addressed to the first wireless station and the second wireless station and requests uplink data information from each of the first wireless station and the second wireless station,

wherein the fifth frame includes uplink data information from the first wireless station and includes a station identifier to uniquely identify the first wireless station to the access point.

7. The method of claim 6, wherein the uplink data information includes one or more of a queue size of buffered data for the first wireless station, traffic class or quality of service information of the buffered data, preferred modulation and coding level for uplink transmissions by the first wireless station, and preferred frequency band for uplink transmissions by the first wireless station.

8. The method of claim 1, further comprising:

processing, by the first wireless device, a sixth frame that is received from the access point after transmission of the fifth frame; and

transmitting, by the first wireless device, a seventh frame to the access point, wherein the seventh frame is transmitted in a multiuser uplink transmission that is triggered by the sixth frame.

9. The method of claim 8, wherein the sixth frame is addressed to the first wireless station and the second wireless station and provides scheduling information for transmission of the seventh frame, and

wherein the seventh frame includes data buffered in the first wireless station and is transmitted according to the scheduling information provided by the sixth frame.

10. A method for performing communications in a wireless system, the method comprising:

transmitting, by an access point, a first frame, which is addressed to a first set of stations in the wireless system; and

processing a second frame received from a second set of stations in the wireless system, wherein the second frame is a combination of a plurality of Clear-To-Send. (CTS) frames respectively transmitted by the second set of stations,

wherein the first frame requests use of a shared wireless channel, upon which the first frame is transmitted, for use in multiuser communications and provides implicit timing information for transmitting the second frame,

wherein the second frame provides clearance from the second set of stations to utilize the shared wireless medium, and

wherein each of the plurality of CTS frames are identical.

11. The method of claim 10, further comprising:

processing a set of third frames received a predetermined amount of time following receipt of the second frame, wherein each frame in the set of third frames uniquely identifies a corresponding transmitting station in the second set of stations to the access point.

12. The method of claim 11, further comprising:

generating, by the access point, the first frame using a scrambling code, wherein the second set of wireless stations use the scrambling code to generate the frames that are combined in air to form the second frame.

13. The method of claim 11, further comprising:

transmitting, by the access point, a fourth frame to the first set of stations following receipt of the second frame,

wherein the fourth frame requests uplink data information from the first set of stations,

wherein the set of third frames (1) is transmitted in response to the fourth frame and (2) includes uplink data information from the second set of stations.

14. The method of claim 13, wherein the uplink data information includes one or more of a queue size of buffered data for a station, traffic class or quality of service information of the buffered data, preferred modulation and coding level for uplink transmissions by the station, and preferred frequency band for uplink transmissions by the station.

15. The method of claim 13, wherein the second set of stations is a subset of the first set of stations.

16. The method of claim 13, wherein the second set of stations is identical to the first set of stations.

17. The method of claim 14, further comprising:

transmitting, by the access point, a sixth frame to the second set of stations, wherein the sixth frame is transmitted following receipt of the set of third frames by the access point; and

processing a set of seventh frames by the access point, wherein the set of seventh frames is received in a multiuser uplink transmission from the second set of stations that is triggered by the sixth frame.

18. The method of claim 17, wherein the sixth frame provides scheduling information for transmission of the set of seventh frames, and

wherein each frame in the set of seventh frames includes data buffered in each corresponding station in the second set of stations and is transmitted according to the scheduling information provided by the sixth frame.

19. The method of claim 11, wherein the predetermined amount of time commences after the second frame has been completely received by the access point.