Switching between MIMO and receiver beam forming in a peer-to-peer network

• US 8,238,234 B2
• Filed: 06/03/2009
• Issued: 08/07/2012
• Est. Priority Date: 06/03/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wang, Hua, Wu, Xinzhou, Richardson, Thomas, Viswanath, Pramod, Li, Junyi, Tavildar, Saurabh
• Primary Examiner(s): Vu, Huy D
• Assistant Examiner(s): Beyen, Zewdu A
• Application Number:
  US12/477,363
• Publication Number:
  US 20100309781A1
• Time in Patent Office: 1,161 Days
• Field of Search: None
• US Class Current: 370/229
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
• CPC Class Codes: H04B 7/0871 using different reception schemes, at least one of them being a diversity reception scheme

Abstract

Aspects describe different multiple antenna techniques that can be utilized in a peer-to-peer network based on a network congestion level. A MIMO scheme where a transmitter sends to a receiver multiple spatial streams at substantially the same time in the same traffic segment can be utilized when network congestion level is low. A receiver beam forming scheme where transmitter sends a single stream in a traffic segment and receiver uses multiple receive antennas to maximize signal to noise ratio can be utilized when network congestion level is high. The connection pair (transmitter and receiver) occupy more control resources in the MIMO scheme than the receiver beam forming scheme. The decision related to which technique to utilize can be made at about the same time as a communication is initiated. Further, if network conditions change during a communication, the antenna technique that is utilized can be switched to a different technique during the communication exchange.

Claims

1. A method of operating a first wireless communications device for selection of a multiple antenna scheme for data exchange in a peer-to-peer communications network, wherein the first wireless communications device is equipped with at least two antennas, the method comprising:

determining a level of congestion in the peer-to-peer communications network;

selecting a multiple antenna scheme from a plurality of predetermined multiple antenna schemes as a function of the determined level of congestion;

utilizing the selected multiple antenna scheme to establish a data exchange with a second peer wireless communications device within the peer-to-peer communications network,

wherein the plurality of predetermined multiple antenna schemes comprise a receiver beam forming scheme and a multiple-input-multiple-output (MIMO) scheme,

wherein selecting the multiple antenna scheme from the plurality of predetermined multiple antenna schemes as a function of the determined level of congestion comprises;

selecting the receiver beam forming scheme if the determined level of congestion is high, and

selecting the MIMO scheme if the determined level of congestion is low;

exchanging data with the second peer wireless communications device using the MIMO scheme;

monitoring network conditions for a change in the congestion level;

switching from the MIMO scheme to the receiver beam forming scheme if the congestion level changes from low to high;

releasing one of at least two reserved distinct sets of channel resources; and

continuing to exchange data with the second peer wireless communications device using the receiver beam forming scheme.

2. The method of claim 1, wherein determining a level of congestion in the peer-to-peer communications network comprises:

estimating a number of connections currently active in the peer-to-peer communications network;

comparing the estimated number of active connections with a predetermined active connection threshold; and

determining whether the level of congestion is low or high, wherein the level of congestion is low if the estimated number of active connections is below the active connection threshold and the level of congestion is high if the estimated number of active connections is at or above the active connection threshold.

3. The method of claim 1, wherein determining a level of congestion in the peer-to-peer communications network comprises:

estimating an amount of traffic exchange occurring in the peer-to-peer communications network;

comparing the estimated amount of traffic exchange with a predetermined active connection threshold; and

determining whether the level of congestion is low or high, wherein the level of congestion is low if the estimated amount of traffic is below the active connection threshold and that the level of congestion is high if the estimated amount of traffic is at or above the active connection threshold.

4. The method of claim 1, further comprising:

reserving at least two distinct sets of channel resources if the MIMO scheme is selected;

receiving a first transmission request signal in one of the at least two distinct sets of channel resources, wherein the first transmission request signal indicates the second peer wireless communications device intends to send a first set of data information to the first wireless communications device in a traffic segment;

receiving a second transmission request signal in a different one of the at least two distinct sets of channel resources, wherein the second transmission request signal indicates the second peer wireless communications device intends to send a second set of data to the first wireless communications device in the traffic segment; and

receiving, at the at least two antennas, a data traffic signal in the traffic segment.

5. The method of claim 4, wherein a set of channel resources comprise a tone in an OFDM symbol.

6. The method of claim 4, further comprising:

applying a MIMO receive matrix to the received data traffic signal to generate a first transformed data symbol block and a second transformed data symbol block; and

recovering a first set of data information for the first transformed data symbol block and a second set of data information for the second transformed data symbol block.

7. The method of claim 6, wherein the MIMO receive matrix is calculated to diagonalize a MIMO channel from the second peer wireless communications device to the first wireless communications device.

8. A method of operating a first wireless communications device for selection of a multiple antenna scheme for data exchange in a peer-to-peer communications network, wherein the first wireless communications device is equipped with at least two antennas, the method comprising:

determining a level of congestion in the peer-to-peer communications network;

selecting a multiple antenna scheme from a plurality of predetermined multiple antenna schemes as a function of the determined level of congestion; and

utilizing the selected multiple antenna scheme to establish a data exchange with a second peer wireless communications device within the peer-to-peer communications network,

wherein the plurality of predetermined multiple antenna schemes comprise a receiver beam forming scheme and a multiple-input-multiple-output (MIMO) scheme,

wherein selecting the multiple antenna scheme from the plurality of predetermined multiple antenna schemes as a function of the determined level of congestion comprises;

selecting the receiver beam forming scheme if the determined level of congestion is high, and

selecting the MIMO scheme if the determined level of congestion is low;

exchanging data with the second peer wireless communications device using the receiver beam forming scheme;

monitoring network conditions for a change in the congestion level;

switching from the receiver beam forming scheme to the MIMO scheme if the congestion level changes from high to low;

reserving at least one additional set of channel resources, wherein the one additional set of channel resources is distinct from an already reserved set of channel resources; and

continuing to exchange data with the second peer wireless communications device using the MIMO scheme.

9. The method of claim 8, further comprising:

reserving one set of channel resources if the receiver beam forming scheme is selected;

receiving a transmission request signal in the set of channel resources, wherein the transmission request signal indicates the second peer wireless communications device intends to send a set of data information to the first wireless communications device in a traffic segment; and

receiving, at the at least two antennas, a data traffic signal in the traffic segment.

10. The method of claim 9, further comprising:

applying a receiver beam forming vector to the received data traffic signal to generate a transformed data symbol block; and

recovering a set of data information from the transformed data symbol block.

11. The method of claim 10, wherein the receiver beam forming vector is calculated to maximize the signal to interference plus noise ratio of the transformed data symbol block.

12. A communications apparatus, comprising:

a memory that retains instructions related to ascertaining whether a level of congestion in a peer-to-peer communications network is a high level of congestion or a low level of congestion, selecting a multiple antenna scheme from a plurality of predetermined multiple antenna schemes as a function of whether the congestion level is low or high, and utilizing the selected multiple antenna scheme to exchange data with a peer node; and

a processor, coupled to the memory, configured to execute the instructions retained in the memory,

wherein the plurality of predetermined multiple antenna schemes comprise a receiver beam forming scheme and a multiple-input-multiple-output (MIMO) scheme, and

wherein the memory retains further instructions related to;

selecting the receiver beam forming scheme if the ascertained level of congestion is high,

selecting the MIMO scheme if the ascertained level of congestion is low,

exchanging data with the peer node using the MIMO scheme;

monitoring network conditions for a change in the congestion level,

switching from the MIMO scheme to the receiver beam forming scheme if the congestion level changes from low to high,

releasing one of two or more reserved distinct sets of channel resources, and

continuing to exchange data with the peer node using the receiver beam forming scheme.

13. The communications apparatus of claim 12, wherein when the MIMO scheme is chosen, the memory retains further instructions related to reserving two or more distinct sets of channel resources, receiving a first transmission request signal in one of the two or more distinct sets of channel resources, receiving a second transmission request signal in a different one of the two or more distinct sets of channel resources, and receiving a data traffic signal in the traffic segment, wherein the first transmission request signal indicates the peer node intends to send a first set of data information in a traffic segment and the second transmission request signal indicates the peer node intends to send a second set of data in a traffic segment.

14. A communications apparatus that exchanges data in a peer-to-peer communications network, comprising:

means for evaluating a network congestion level;

means for selecting a multiple antenna scheme from a plurality of predetermined multiple antenna schemes as a function of the network congestion level; and

means for utilizing the selected multiple antenna scheme to exchange data with a peer node within the peer-to-peer communications network,

wherein the plurality of predetermined multiple antenna schemes comprise a receiver beam forming scheme and a multiple-input-multiple-output (MIMO) scheme,

wherein the means for selecting the multiple antenna scheme from the plurality of predetermined multiple antenna schemes as a function of the network congestion level is configured to;

select the receiver beam forming scheme if the evaluated level of congestion is high, and

select the MIMO scheme if the evaluated level of congestion is low;

means for exchanging data with the peer node using the MIMO scheme;

means for monitoring network conditions for a change in the network congestion level;

means for switching from the MIMO scheme to the receiver beam forming scheme if the network congestion level changes from low to high;

means for releasing one of at least two reserved distinct sets of channel resources; and

means for continuing to exchange data with the peer node using the receiver beam forming scheme.

15. The communications apparatus of claim 14, wherein the means for evaluating the network congestion level estimates a number of active connections, compares the estimated number of active connections with a predetermined active connection threshold, and establishes whether the congestion level is low or high, wherein the congestion level is low if the estimated number of active connections is below the active connection threshold and the congestion level is high if the estimated number of active connections is at or above the active connection threshold.

16. The communications apparatus of claim 14, wherein the means for evaluating the network congestion level estimates an amount of traffic exchange occurring in the peer-to-peer communications network, compares the estimated amount of traffic exchange with a predetermined active connection threshold, and establishes whether the congestion level is high or low, wherein the congestion level is high if the estimated amount of traffic is at or above the active connection threshold and the congestion level is low if the estimated amount of traffic is below the active connection threshold.

17. A computer program product, comprising:

a non-transitory computer-readable medium comprising;

a first set of codes for causing a computer to estimate a congestion level in a peer-to-peer communication network;

a second set of codes for causing the computer to select a receiver beam forming scheme or a MIMO scheme for data exchange as a function of the congestion level, wherein the second set of codes causes the computer to select the receiver beam forming scheme if the estimated level of congestion is high and select the MIMO scheme if the estimated level of congestion is low;

a third set of codes for causing the computer to continue to monitor the congestion level during the data exchange in order to determine if the congestion level changes; and

a fourth set of codes for causing the computer to switch between the receiver beam forming scheme and the MIMO scheme if the congestion level changes, wherein the switch is from the receiver beam forming scheme to the MIMO scheme if the congestion level changes from high to low and from the MIMO scheme to the receiver beam forming scheme if the congestion level changes from low to high;

a fifth set of codes for causing the computer to exchange data with a peer node using the MIMO scheme;

a sixth set of codes for causing the computer to release one of at least two reserved distinct sets of channel resources when the fourth set of codes causes the computer to switch from the MIMO scheme to the receiver beam forming scheme if the congestion level changes from low to high; and

a seventh set of codes for causing the computer to continue to exchange data with the peer node using the receiver beam forming scheme.

18. The computer program product of claim 17, wherein the congestion level is low if the estimated congestion level is below a predetermined congestion threshold and the congestion level is high if the estimated congestion level is at or above the predetermined congestion threshold.

19. At least one processor for use in a communications apparatus that exchanges data in a peer-to-peer communications network, the processor configured to cause the apparatus to use different antenna techniques to exchange data with a peer wireless communications device within the peer-to-peer communications network, the processor comprising:

a first module for determining whether a level of congestion in the peer-to-peer communications network is a low level or a high level;

a second module for selecting a multiple antenna scheme from a plurality of predetermined multiple antenna schemes as a function of whether the level of congestion is the low level or the high level; and

a third module for exchanging data with the peer wireless communications device using the selected multiple antenna scheme,

wherein the plurality of predetermined multiple antenna schemes comprise a receiver beam forming scheme and a MIMO scheme and the third module utilizes the MIMO scheme to exchange data with the peer wireless communications device, the processor further comprising;

a fourth module for monitoring network conditions for a change in the level of congestion;

a fifth module for switching from the MIMO scheme to the receiver beam forming scheme if the level of congestion level changes from the low level to the high level; and

a sixth module for releasing one of at least two reserved distinct sets of channel resources, the third module continues to exchange data with the peer wireless communications device using the receiver beam forming scheme.

20. At least one processor for use in a communications apparatus that exchanges data in a peer-to-peer communications network, the processor configured to cause the apparatus to use different antenna techniques to exchange data with a peer wireless communications device within the peer-to-peer communications network, the processor comprising:

a first module for determining whether a level of congestion in the peer-to-peer communications network is a low level or a high level;

a second module for selecting a multiple antenna scheme from a plurality of predetermined multiple antenna schemes as a function of whether the level of congestion is the low level or the high level; and

a third module for exchanging data with the peer wireless communications device using the selected multiple antenna scheme,

wherein the plurality of predetermined multiple antenna schemes comprise a receiver beam forming scheme and a MIMO scheme and the third module utilizes the receiver beam forming scheme to exchange data with the peer wireless communications device, the processor further comprising;

a fourth module for monitoring network conditions for a change in the level of congestion;

a fifth module for switching from the receiver beam forming scheme to the MIMO scheme if the level of congestion changes from the high level to the low level; and

a sixth module for reserving at least one set of channel resources, wherein the one set of channel resources is distinct from an already reserved set of channel resources, the third module continues to exchange data with the peer wireless communications device using the MIMO scheme.

21. A communications apparatus, comprising:

a memory that retains instructions related to ascertaining whether a level of congestion in a peer-to-peer communications network is a high level of congestion or a low level of congestion, selecting a multiple antenna scheme from a plurality of predetermined multiple antenna schemes as a function of whether the congestion level is low or high, and utilizing the selected multiple antenna scheme to exchange data with a peer node; and

a processor, coupled to the memory, configured to execute the instructions retained in the memory,

wherein the plurality of predetermined multiple antenna schemes comprise a receiver beam forming scheme and a multiple-input-multiple-output (MIMO) scheme, and

wherein the memory retains further instructions related to;

selecting the receiver beam forming scheme if the ascertained level of congestion is high,

selecting the MIMO scheme if the ascertained level of congestion is low,

exchanging data with the peer node using the receiver beam forming scheme,

monitoring network conditions for a change in the congestion level,

switching from the receiver beam forming scheme to the MIMO scheme if the congestion level changes from high to low,

reserving at least one additional set of channel resources, wherein the one additional set of channel resources is distinct from an already reserved set of channel resources, and

continuing to exchange data with the peer node using the MIMO scheme.

22. The communication apparatus of claim 21, wherein when the receiver beam forming scheme is selected, the memory retains further instructions related to reserving one set of channel resources, receiving a transmission request signal in the set of channel resources, and receiving a data traffic signal in the traffic segment, wherein the transmission request signal indicates the peer node intends to send a set of data information in a traffic segment.

23. A communications apparatus that exchanges data in a peer-to-peer communications network, comprising:

means for evaluating a network congestion level;

means for selecting a multiple antenna scheme from a plurality of predetermined multiple antenna schemes as a function of the network congestion level; and

means for utilizing the selected multiple antenna scheme to exchange data with a peer node within the peer-to-peer communications network,

wherein the plurality of predetermined multiple antenna schemes comprise a receiver beam forming scheme and a multiple-input-multiple-output (MIMO) scheme,

wherein the means for selecting the multiple antenna scheme from the plurality of predetermined multiple antenna schemes as a function of the network congestion level is configured to;

select the receiver beam forming scheme if the evaluated level of congestion is high, and

select the MIMO scheme if the evaluated level of congestion is low;

means for exchanging data with the peer node using the receiver beam forming scheme;

means for monitoring network conditions for a change in the network congestion level;

means for switching from the receiver beam forming scheme to the MIMO scheme if the network congestion level changes from high to low;

means for reserving at least one additional set of channel resources, wherein the one additional set of channel resources is distinct from an already reserved set of channel resources; and

means for continuing to exchange data with the peer node using the MIMO scheme.

24. A computer program product, comprising:

a non-transitory computer-readable medium comprising;

a first set of codes for causing a computer to estimate a congestion level in a peer-to-peer communication network;

a second set of codes for causing the computer to select a receiver beam forming scheme or a MIMO scheme for data exchange as a function of the congestion level, wherein the second set of codes causes the computer to select the receiver beam forming scheme if the estimated level of congestion is high and select the MIMO scheme if the estimated level of congestion is low;

a third set of codes for causing the computer to continue to monitor the congestion level during the data exchange in order to determine if the congestion level changes; and

a fourth set of codes for selectively switching between the receiver beam forming scheme and the MIMO scheme if the congestion level changes, wherein the switch is from the receiver beam forming scheme to the MIMO scheme if the congestion level changes from high to low and from the MIMO scheme to the receiver beam forming scheme if the congestion level changes from low to high;

a fifth set of codes for causing the computer to exchange data with a peer node using the receiver beam forming scheme;

a sixth set of codes for causing the computer to reserve at least one additional set of channel resources when the second set of codes causes the computer to switch from the receiver beam forming scheme to the MIMO scheme if the congestion level changes from high to low, wherein the one additional set of channel resources is distinct from an already reserved set of channel resources; and

a seventh set of codes for causing the computer to continue to exchange data with the peer node using the MIMO scheme.