TECHNIQUES FOR CONFIGURING PREAMBLE AND OVERHEAD SIGNALS FOR TRANSMISSIONS IN AN UNLICENSED RADIO FREQUENCY SPECTRUM BAND

• US 20150271847A1
• Filed: 12/29/2014
• Published: 09/24/2015
• Est. Priority Date: 03/21/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Luo, Tao, Patel, Shimman Arvind, Chen, Wanshi, Bhushan, Naga, Wei, Yongbin, Xu, Hao, Damnjanovic, Aleksandar, Ji, Tingfang, Malladi, Durga Prasad, Yerramalli, Srinivas, Gaal, Peter
• Granted Patent: US 10,499,421 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/26025 Numerology, i.e. varying one or more of symbol duration, subcarrier spacing, Fourier transform size, sampling rate or down-clocking allocating sub-channels of the transmission path H04L5/003
• CPC Class Codes: H04L 27/26035 Maintenance of orthogonality, e.g. for signals exchanged between cells or users, or by using covering codes or sequences using different training sequence per antenna H04B7/0684; code allocation H04J13/16
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0028 Variable division signaling therefor H04L5/0092
• CPC Class Codes: H04L 5/003 Arrangements for allocating sub-channels of the transmission path
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path
• CPC Class Codes: H04L 5/0092 Indication of how the channel is divided
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

Techniques are described for wireless communication. A first method includes transmitting a first signal to indicate accessing a first channel in a radio frequency spectrum band, and transmitting information with the first signal in the radio frequency spectrum band. A second method includes winning contention to access a radio frequency spectrum band, and after the winning contention to access the radio frequency spectrum band, transmitting a first signal to align a starting point of a second signal with a reference boundary associated with the radio frequency spectrum band. A third method includes winning contention to access a radio frequency spectrum band during a first frame period, the first frame selected from a plurality of different frame periods, and transmitting a signal at a periodicity during one or more subframes of the first frame period for each of the plurality of different frame periods.

Claims

1. A method for wireless communication, comprising:

transmitting a first signal to indicate accessing a first channel in a radio frequency spectrum band; and

transmitting information with the first signal in the radio frequency spectrum band.

2. The method of claim 1, wherein the information comprises system information.

3. The method of claim 1, wherein the transmitting information with the first signal comprises:

transmitting information as part of the first signal.

4. The method of claim 3, wherein the first signal is generated based at least in part on a sequence.

5. The method of claim 4, wherein the sequence is a function of the information.

6. The method of claim 1, wherein the transmitting information with the first signal comprises:

transmitting information in a second signal along with the first signal, wherein the second signal is separate from the first signal.

7. The method of claim 1, further comprising:

selecting a first phase from among a plurality of phases for transmission of the first signal, wherein different phases of the plurality of phases correspond to different information;

wherein the transmitting information with the first signal comprises transmitting the first signal at the first phase.

8. The method of claim 1, wherein the first signal is transmitted during a first orthogonal frequency-division multiplexing (OFDM) symbol period of the radio frequency spectrum band and a second OFDM symbol period of the radio frequency spectrum band and the information is transmitted during the second OFDM symbol period.

9. The method of claim 8, further comprising:

transmitting a second signal carrying the information during the second OFDM symbol period of the radio frequency spectrum band;

wherein the first signal provides a phase reference for the second signal.

10. The method of claim 1, wherein the information indicates a number of subframes of a frame that are used for transmission in the radio frequency spectrum band.

11. The method of claim 1, wherein the information indicates a number of antennas to use for receiving a transmission carried on a component carrier in the radio frequency spectrum band.

12. The method of claim 11, further comprising:

adjusting a modulation and coding scheme (MCS) for transmission of the component carrier in the radio frequency spectrum band based at least in part on the number of antennas to use to receive the component carrier in the radio frequency spectrum band.

13. The method of claim 11, wherein the number of antennas to use for receiving a transmission carried on the component carrier in the radio frequency spectrum band is determined based at least in part on an uplink configuration or a downlink configuration associated with the component carrier.

14. The method of claim 11, wherein the number of antennas to use for receiving a transmission carried on the component carrier in the radio frequency spectrum band is determined based at least in part on a clear channel assessment (CCA) procedure associated with each of a plurality of component carriers used to serve a user equipment (UE).

15. The method of claim 11, further comprising:

selecting the number of antennas to use for receiving a transmission carried on the component carrier in the radio frequency spectrum band for each subframe of a frame of the component carrier in the radio frequency spectrum band.

16. A method for wireless communications, comprising:

winning contention to access a radio frequency spectrum band; and

after the winning contention to access the radio frequency spectrum band, transmitting a first signal to align a starting point of a second signal with a reference boundary associated with the radio frequency spectrum band.

17. The method of claim 16, wherein the radio frequency spectrum band comprises an unlicensed radio frequency spectrum band.

18. The method of claim 16, further comprising:

accessing timing information; and

determining the reference boundary based at least in part on the timing information and the winning contention to access the radio frequency spectrum band.

19. The method of claim 16, wherein the first signal comprises a variable length training sequence.

20. The method of claim 16, wherein the first signal comprises a variable length training sequence and at least one fixed length training sequence.

21. The method of claim 16, further comprising:

operating in a listen before talk (LBT)-load based equipment (LBE) mode of operation in the radio frequency spectrum band.

22. The method of claim 16, wherein the reference boundary comprises a boundary of an orthogonal frequency-division multiplexing (OFDM) symbol period associated with the radio frequency spectrum band.

23. The method of claim 22, wherein the first signal is associated with a contention priority, and wherein the first signal is transmitted during a portion of the OFDM symbol period based at least in part on the contention priority.

24. An apparatus for wireless communications, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to;

win contention to access a radio frequency spectrum band; and

after winning contention to access the radio frequency spectrum band, transmit a first signal to align a starting point of a second signal with a reference boundary associated with the radio frequency spectrum band.

25. A method for wireless communication, comprising:

winning contention to access a radio frequency spectrum band during a first frame period, the first frame period selected from a plurality of different frame periods; and

transmitting a signal at a periodicity during one or more subframes of the first frame period for each of the plurality of different frame periods.

26. The method of claim 25, wherein the periodicity is a fixed periodicity.

27. The method of claim 25, wherein the transmitting the signal at the periodicity comprises:

transmitting the signal at a fixed time and a fixed frequency location.

28. The method of claim 25, wherein the signal is transmitted in an overhead channel.

29. The method of claim 25, wherein the first frame period comprises a listen before talk (LBT) frame period.

30. The method of claim 25, further comprising:

determining whether the signal collides with a timing of a contention procedure; and

preventing transmission of the signal based at least in part on the determination that the signal collides with the timing of the contention procedure.