Cell discovery in a wireless network using an unlicensed radio frequency spectrum band

Patent metadata

Field	Value
Publication number	US-2016007353-A1
Application number	US-201514789301-A
Country	US
Kind code	A1
Filing date	Jul 1, 2015
Priority date	Jul 3, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

Techniques for transmitting and receiving wireless communications over an unlicensed radio frequency spectrum band are disclosed, including techniques for transmitting and receiving service information blocks over the unlicensed radio frequency spectrum band, techniques for gaining access to the unlicensed radio frequency spectrum band by performing extended clear channel assessments (eCCAs), techniques for transmitting and receiving synchronization signals and reference signals over the unlicensed radio frequency spectrum band, techniques for communicating locations of reference signals, and techniques for communicating availability of certain resources to be combined across multiple different transmissions.

First claim

1 . A method of wireless communication, comprising:
generating a system information block (SIB) comprising a plurality of parameters related to a base station; transmitting the SIB via a control channel over an unlicensed radio frequency spectrum band; and transmitting a reference signal indicating a portion of the control channel that includes the SIB.

2 . The method of claim 1 , wherein the control channel comprises a plurality of resource blocks, and wherein the reference signal indicates a subset of the plurality of resource blocks that include the SIB.

3 . The method of claim 2 , wherein the reference signal comprises a physical cell identity (PCI), and wherein the subset of the plurality of resource blocks are mapped to the PCI.

4 . The method of claim 2 , wherein the subset of the plurality of resource blocks are predetermined based on a timing of the reference signal.

5 . The method of claim 2 , wherein the reference signal comprises information indicating a location of the subset of resource blocks.

6 . The method of claim 1 , wherein the SIB is transmitted over the unlicensed radio frequency spectrum band during a clear channel assessment (CCA)-exempt transmission (CET) subframe associated with the base station.

7 . The method of claim 1 , further comprising:
performing a clear channel assessment (CCA) prior to a non-CCA-exempt transmission (non-CET) subframe associated with opportunistic system information block transmissions; and transmitting the SIB on the non-CET subframe when the CCA is successful.

8 . The method of claim 1 , wherein the plurality of parameters comprise a system frame number (SFN).

9 . The method of claim 8 , wherein the reference signal is transmitted with a periodicity that exceeds a length of a radio frame.

10 . The method of claim 9 , wherein the periodicity corresponds to a time period for incrementing the SFN.

11 . A method of wireless communication, comprising:
receiving a reference signal over an unlicensed radio frequency spectrum band, the reference signal indicating a portion of a control channel that includes a system information block (SIB), the SIB comprising a plurality of parameters related to a base station; receiving the control channel; and decoding the SIB based on the indicated portion of the control channel that includes the SIB.

12 . The method of claim 11 , wherein the control channel comprises a plurality of resource blocks, and wherein the reference signal indicates a subset of the plurality of resource blocks that include the SIB.

13 . The method of claim 12 , wherein the reference signal comprises a physical cell identity (PCI), and wherein the subset of the plurality of resource blocks are mapped to the PCI.

14 . The method of claim 12 , wherein the reference signal comprises information indicating a location of the subset of resource blocks.

15 . The method of claim 11 , wherein the plurality of parameters comprise a system frame number (SFN).

16 . The method of claim 15 , wherein the reference signal is transmitted with a periodicity that exceeds a length of a radio frame.

17 . The method of claim 16 , wherein the periodicity corresponds to a time period for incrementing the SFN.

18 . The method of claim 17 , wherein the decoding comprises:
combining a plurality of resource blocks including a plurality of transmissions of the SIB; and decoding the combined plurality of resource blocks to generate the SIB.

19 . An apparatus for wireless communication, comprising:
a processor; and memory coupled to the processor, wherein the processor is configured to: generate a system information block (SIB) comprising a plurality of parameters related to a base station; transmit the SIB via a control channel over an unlicensed radio frequency spectrum band; and transmit a reference signal indicating a portion of the control channel that includes the SIB.

20 . The apparatus of claim 19 , wherein the control channel comprises a plurality of resource blocks, and wherein the reference signal indicates a subset of the plurality of resource blocks that include the SIB.

21 . The apparatus of claim 20 , wherein the reference signal comprises a physical cell identity (PCI), and wherein the subset of the plurality of resource blocks are mapped to the PCI.

22 . The apparatus of claim 20 , wherein the subset of the plurality of resource blocks are predetermined based on a timing of the reference signal.

23 . The apparatus of claim 19 , wherein the SIB is transmitted over the unlicensed radio frequency spectrum band during a clear channel assessment (CCA)-exempt transmission (CET) subframe associated with the base station.

24 . The apparatus of claim 19 , wherein the processor is further configured to:
perform a clear channel assessment (CCA) prior to a non-CCA-exempt transmission (non-CET) subframe associated with opportunistic system information block transmissions; and transmit the SIB on the non-CET subframe when the CCA is successful.

25 . The apparatus of claim 19 , wherein the plurality of parameters comprise a system frame number (SFN).

26 . An apparatus for wireless communication, comprising:
a processor; and memory coupled to the processor, wherein the processor is configured to: receive a reference signal over an unlicensed radio frequency spectrum band, the reference signal indicating a portion of a control channel that includes a system information block (SIB), the SIB comprising a plurality of parameters related to a base station; receive the control channel; and decode the SIB based on the indicated portion of the control channel that includes the SIB.

27 . The apparatus of claim 26 , wherein the control channel comprises a plurality of resource blocks, and wherein the reference signal indicates a subset of the plurality of resource blocks that include the SIB.

28 . The apparatus of claim 27 , wherein the reference signal comprises a physical cell identity (PCI), and wherein the subset of the plurality of resource blocks are mapped to the PCI.

29 . The apparatus of claim 27 , wherein the reference signal comprises information indicating a location of the subset of resource blocks.

30 . The apparatus of claim 26 , wherein the plurality of parameters comprise a system frame number (SFN).

Assignees

• Qualcomm Inc

Inventors

• Malladi Durga Prasad
• Luo Tao
• Damnjanovic Aleksandar
• Wei Yongbin
• Vajapeyam Madhavan Srinivasan
• Chen Wanshi

Classifications

• H04W48/16 Primary

  Discovering, processing access restriction or access information · CPC title

• H04W48/12

  using downlink control channel · CPC title

• H04W72/0453 Primary

  Resources in frequency domain, e.g. a carrier in FDMA · CPC title

• H04W48/20

  Selecting an access point · CPC title

• H04L5/0053

  Allocation of signalling, i.e. of overhead other than pilot signals · CPC title