Wireless communications system that supports multiple modes of operation

• US 9,736,832 B2
• Filed: 03/10/2016
• Issued: 08/15/2017
• Est. Priority Date: 09/01/2000
• Status: Expired due to Fees

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Heath, Jr., Robert W., Krishnamoorthy, Rajeev, Sebastian, Peroor K., Paulraj, Arogyaswami J.
• Primary Examiner(s): Lai, Andrew
• Assistant Examiner(s): LEE, ANDREW CHUNG CHEUNG
• Application Number:
  US15/066,129
• Publication Number:
  US 20160262134A1
• Time in Patent Office: 523 Days
• 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 system is presented that adapts its mode of operation between spatial and non-spatial multiplexing in response to transmission-specific variables. Mode determination logic determines, in response to a received signal, if spatial or non-spatial multiplexing should be used to transmit a subscriber datastream between the BTS and the UE. The mode determination logic receives a measure of a transmission characteristic of the signal, compares the transmission characteristic to a transmission characteristic threshold and selects either spatial or non-spatial multiplexing in response to the comparison. The transmission characteristic includes at least one of delay spread, post-processing signal-to-noise ratio, CRC failure, residual inter-symbol interference, mean square error, coherence time, and path loss.

Claims

1. An apparatus of a base transceiver station (BTS), the apparatus comprising:

transceiver circuitry arranged to;

receive capability information from a subscriber unit served by the BTS, the capability information configured to indicate whether the subscriber unit supports a particular transmission mode of a plurality of transmission modes, and

communicate with the subscriber unit via the particular transmission mode based at least in part on the capability information of the subscriber unit; and

processing circuitry in communication with the transceiver circuitry and arranged to;

select the particular transmission mode for data transmission to the subscriber unit based on feedback reported by the subscriber unit when the capability information indicates the particular transmission mode is supported, and

cause the transceiver circuitry to use the transmission mode for the data transmission to the subscriber unit in response to selection of the particular transmission mode.

2. The apparatus of the BTS of claim 1, further comprising:

a parser and combiner configured to break a subscriber data stream to be transmitted by the transceiver circuitry to the subscriber unit into substreams and re-assemble substreams from the subscriber unit into an original subscriber data stream.

3. The apparatus of the BTS of claim 2, wherein:

the subscriber data stream comprises a plurality of sequential packets, and

the parser and combiner is configured separate the sequential packets such that the substreams contain non-sequential packets.

4. The apparatus of the BTS of claim 1, further comprising:

a plurality of spatially separate antennas configured to communicate with the subscriber unit, a number of the plurality of spatially separate antennas used for communication with the subscriber unit dependent on the particular transmission mode selected for the subscriber unit.

5. The apparatus of the BTS of claim 4, wherein:

the data transmission to the subscriber unit is transmitted from the plurality of spatially separate antennas over a same frequency.

6. The apparatus of the BTS of claim 1, wherein:

the transmission modes include at least a single antenna mode, a transmit diversity mode, and a spatial multiplexing mode.

7. The apparatus of the BTS of claim 1, wherein:

the subscriber data stream comprises a plurality of packets,

at least one of the packets comprises a control channel that contains bits dedicated to communicating information related to a mode of operation between the BTS and the subscriber unit, and

the control channel is located in a header of the at least one of the packets.

8. The apparatus of the BTS of claim 1, wherein the transceiver circuitry is further configured to:

communicate a control channel that contains bits dedicated to communicating information related to a mode of operation between the BTS and the subscriber unit, the control channel provided over at least one of a dedicated transmission frequency or a dedicated time slot.

9. The apparatus of the BTS of claim 1, wherein the transceiver circuitry is further configured to:

communicate a control channel between the BTS and the subscriber unit, the control channel free from mode determination information.

10. The apparatus of the BTS of claim 1, wherein the transceiver circuitry is further configured to:

communicate a control channel that contains bits dedicated to communicating information related to a mode of operation between the BTS and the subscriber unit, the information comprising training information to establish and fine tune a communications channel between the BTS and the subscriber unit.

11. The apparatus of the BTS of claim 1, wherein:

the feedback comprises transmission characteristics that comprise at least one of;

delay spread, post-processing signal-to-noise ratio, a number of cyclical redundancy check (CRC) failures, residual inter-symbol interference (ISI), mean square error, coherence time, and path loss, and

the processing circuitry is further configured to adapt to select the transmission mode based on a comparison between the transmission characteristics and one or more transmission characteristic thresholds, at least one of the transmission characteristic thresholds dependent on a type of a subscriber unit from which a signal associated with the transmission characteristic is measured.

12. The apparatus of the BTS of claim 1, wherein the transceiver circuitry is further configured to:

periodically receive the feedback, and

indicate to the subscriber unit the transmission mode after each feedback is received independent of whether the transmission mode is switched in response to the feedback.

13. The apparatus of the BTS of claim 1, wherein the transceiver circuitry is further configured to:

periodically receive the feedback, and

indicate to the subscriber unit the transmission mode in response to reception of feedback that causes the transmission mode to be switched and avoid an indication of the transmission mode in response to reception of feedback that causes the transmission mode to remain constant.

14. The apparatus of the BTS of claim 1, wherein:

the feedback is link maintenance feedback that is received after a link exists between the BTS and the subscriber unit.

15. The apparatus of the BTS of claim 1, wherein:

the feedback is link initiation feedback that is received during link establishment between the BTS and the subscriber unit when at least one of the subscriber unit is powered up or the subscriber unit enters a subscriber area served by the BTS.

16. The apparatus of the BTS of claim 1, wherein the transceiver circuitry is further configured to:

transmit over a dedicated control channel to the subscriber unit, after reception of the capability information, an indication of whether the BTS supports the particular transmission mode.

17. The apparatus of the BTS of claim 16, wherein the transceiver circuitry is further configured to:

avoid transmission of the indication when the BTS in unable to support the particular transmission mode.

18. The apparatus of the BTS of claim 1, wherein the processing circuitry is further configured to:

determine the transmission mode to transmit data based on a location of the subscriber unit within a cell served by the BTS.

19. The apparatus of the BTS of claim 1, wherein the processing circuitry is further configured to:

determine the transmission mode to transmit data based on a speed of the subscriber unit.

20. An apparatus of a subscriber unit, the apparatus comprising:

transceiver circuitry arranged to communicate with a base transceiver station (BTS); and

processing circuitry in communication with the transceiver circuitry and arranged to;

encode capability information for transmission to the BTS, the capability information configured to indicate whether the subscriber unit supports a particular transmission mode of a plurality of transmission modes,

decode, after transmission of the capability information, an indication from the BTS of whether the BTS supports the particular transmission mode,

generate periodic feedback for transmission to the BTS, the feedback comprising at least one transmission characteristic used to compare to a threshold, the threshold dependent on a type of the subscriber unit from which a signal associated with the at least one transmission characteristic is measured, and

communicate with the BTS via the transmission mode based on the capability information, the indication and the feedback.

21. The apparatus of the subscriber unit of claim 20, wherein the processing circuitry is further configured to:

periodically generate the feedback, and

decode an indication of the transmission mode from the BTS after each feedback is transmitted independent of whether the transmission mode is switched in response to the feedback.

22. The apparatus of the subscriber unit of claim 20, wherein the processing circuitry is further configured to:

periodically generate the feedback, and

decode an indication of the transmission mode from the BTS in response to transmission of feedback that causes the transmission mode to be switched free from decoding of an indication of the transmission mode in response to transmission of feedback that causes the transmission mode to remain constant.

23. The apparatus of the subscriber unit of claim 20, wherein the processing circuitry is further configured to:

decode the transmission mode to communicate data based on at least one of a location of the subscriber unit within a cell served by the BTS or a speed of the subscriber unit outside of the cell.

24. An apparatus of a base transceiver station (BTS), the apparatus comprising:

transceiver circuitry arranged to;

receive capability information from a subscriber unit served by the BTS, the capability information configured to indicate whether the subscriber unit supports spatial multiplexing, and communicate with the subscriber unit via spatial multiplexing based at least in part on the capability information of the subscriber unit; and

processing circuitry in communication with the transceiver circuitry and arranged to;

select spatial multiplexing for data transmission to the subscriber unit based on feedback reported by the subscriber unit when the capability information indicates spatial multiplexing is supported, the feedback comprising transmission characteristics, whether the spatial multiplexing is selected based on a comparison between the transmission characteristics and one or more transmission characteristic thresholds, at least one of the transmission characteristic thresholds dependent on a type of a subscriber unit from which a signal associated with a particular transmission characteristic of the transmission characteristics is measured, and

cause the transceiver circuitry to use spatial multiplexing for the data transmission to the subscriber unit in response to selection of spatial multiplexing.

25. The apparatus of the BTS of claim 24, wherein the transceiver circuitry is further configured to:

periodically receive the feedback, and

indicate to the subscriber unit the transmission mode after each feedback is received independent of whether the transmission mode is switched in response to the feedback.

26. The apparatus of the BTS of claim 24, wherein the transceiver circuitry is further configured to:

periodically receive the feedback, and

indicate to the subscriber unit the transmission mode in response to reception of feedback that causes the transmission mode to be switched and avoid an indication of the transmission mode in response to reception of feedback that causes the transmission mode to remain constant.

27. The apparatus of the BTS of claim 24, wherein the processing circuitry is further configured to:

determine the transmission mode to transmit data based on a location of the subscriber unit within a cell served by the BTS.