Wireless communications system that supports multiple modes of operation

• US 8,345,637 B2
• Filed: 07/02/2009
• Issued: 01/01/2013
• Est. Priority Date: 09/01/2000
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Krishnamoorthy, Rajeev, Paulraj, Arogyaswami J., Sebastian, Peroor K., Heath, Robert W.
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Boakye, Alexander O
• Application Number:
  US12/496,922
• Publication Number:
  US 20100046429A1
• Time in Patent Office: 1,279 Days
• Field of Search: 370/332, 370/342, 370/337, 370/310, 370/328, 370/329, 370/341, 370/326, 370/431, 370/319, 370/465, 370/468, 455/509, 455/560, 375/299
• US Class Current: 370/332
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A wireless communications adapts its mode of operation between spatial multiplexing and non-spatial multiplexing in response to transmission-specific variables. An embodiment of a wireless communications system for transmitting information between a base transceiver station and a subscriber unit includes mode determination logic. The mode determination logic is in communication with the base transceiver station and the subscriber unit. The mode determination logic determines, in response to a received signal, if a subscriber data stream should be transmitted between the base transceiver station and the subscriber unit utilizing spatial multiplexing or non-spatial multiplexing.

Claims

1. A wireless communications system for transmitting information between a base transceiver station and a subscriber unit, comprising:

a mode determinator, in communication with the base transceiver station and the subscriber unit, capable of determining, in response to a received signal, if a subscriber datastream should be transmitted between the base transceiver station and the subscriber unit utilizing spatial multiplexing or non-spatial multiplexing, the mode determinator comprising;

a comparator capable of comparing a delay spread measure for the received signal to a delay spread threshold; and

a selector capable of selecting a spatial multiplexing operational mode for transmission of the subscriber datastream if the delay spread measure does not exceed the delay spread threshold and capable of a selecting non-spatial multiplexing operational mode if the delay spread measure exceeds the delay spread threshold.

2. The wireless communications system according to claim 1, wherein the base transceiver station and the subscriber unit are capable of utilizing a multiple access protocol to transmit the subscriber datastream, and

wherein the multiple access protocol comprises a code-division multiple access protocol, a frequency-division multiple access protocol, a time-division multiple access protocol, a space-division multiple access protocol, an orthogonal frequency division multiple access protocol, an orthogonal division multiple access protocol, or a quasi-orthogonal division multiple access protocol, or a combination thereof.

3. The wireless communications system according to claim 1, wherein operational mode information is communicated between the base transceiver station and the subscriber unit over a control channel.

4. The wireless communications system according to claim 1, wherein the mode determinator comprises an input capable of receiving system specifications related to a signal receive capability of at least one of the base transceiver station and the subscriber unit.

5. The wireless communications system according to claim 1, wherein the mode determinator comprises an input capable of receiving system specifications related to a signal transmit capability of at least one of the base transceiver station and the subscribe unit.

6. The wireless communications system according to claim 1, wherein the mode determinator is configured to:

determine if both the base transceiver station and the subscriber unit support spatial multiplexing; and

select a non-spatial multiplexing operational mode for transmission of the subscriber datastream if one of the base transceiver station and the subscriber unit does not support spatial multiplexing.

7. The wireless communications system according to claim 1, wherein non-spatial multiplexing transmission modes comprise single-carrier transmissions, multi-carrier transmissions, multi-code transmission, transmit diversity, or beamforming, or a combination thereof.

8. The wireless communications system according to claim 1, wherein transmit diversity comprises selection diversity, space-time coding, or maximum ratio combining, or a combination thereof.

9. The wireless communications system according to claim 1, wherein the mode determinator resides within the subscriber unit.

10. The wireless communications system according to claim 1, wherein the mode determinator resides within the base transceiver station.

11. A method for operating a wireless communications system, comprising:

receiving a signal transmission at one of a base transceiver station and a subscriber unit via the wireless communications system;

measuring a delay spread characteristic of the received signal transmission;

comparing the delay spread characteristic to a delay spread threshold; and

selecting a spatial multiplexing operational mode if the delay spread measure does not exceed the delay spread threshold and selecting a non-spatial multiplexing operational mode if the delay spread measure exceeds the delay spread threshold,

wherein the base transceiver station and the subscriber unit utilize a multiple access protocol to transmit the subscriber datastream, and

wherein the multiple access protocol comprises a code-division multiple access protocol, a frequency-division multiple access protocol, a time-division multiple access protocol, a space-division multiple access protocol, an orthogonal frequency division multiple access protocol, an orthogonal division multiple access protocol, or a quasi-orthogonal division multiple access protocol, or a combination thereof.

12. A wireless communications system for transmitting information between a base transceiver station and a subscriber unit, comprising:

a control channel capable of communicating whether a subscriber datastream should be transmitted between the base transceiver station and the subscriber unit utilizing a spatial multiplexing operational mode or a non-spatial multiplexing operational mode; and

a mode determinator,

wherein the control channel is capable of being used to indicate a spatial multiplexing or a non-spatial multiplexing capability of one of the base transceiver station and/or the subscriber unit

wherein the mode determinator is, in communication with the base transceiver station and the subscriber unit, and is capable of determining, in response to a received signal, if the subscriber datastream should be transmitted between the base transceiver station and the subscriber unit utilizing the spatial multiplexing operational mode or the non-spatial multiplexing operational mode.

13. The wireless communications system according to claim 12, wherein the mode determinator comprises an input capable of receiving a measure of a transmission characteristic related to the received signal.

14. The wireless communications system according to claim 13, wherein the mode determinator comprises logic capable of comparing the measured transmission characteristic to a transmission characteristic threshold;

and

capable of selecting one of the spatial multiplexing operational mode and the non-spatial multiplexing operational mode in response to the comparison of the measured transmission characteristic to the transmission characteristic threshold.

15. The wireless communications system according to claim 14, wherein the transmission characteristic comprises a delay spread measure and the transmission characteristic threshold comprises a delay spread threshold, and

wherein the mode determinator is further capable of selecting the spatial multiplexing operational mode if the delay spread measure does not exceed the delay spread threshold and capable of selecting a non-spatial multiplexing operational mode if the delay spread measure exceeds the delay spread threshold.