Techniques for cell-specific reference signal (crs)-based signaling in a shared radio frequency spectrum band

Patent metadata

Field	Value
Publication number	US-2016112169-A1
Application number	US-201514864056-A
Country	US
Kind code	A1
Filing date	Sep 24, 2015
Priority date	Oct 16, 2014
Publication date	Apr 21, 2016
Grant date	—

Abstract

Techniques are described for wireless communication. A first method includes identifying a configuration of a downlink subframe in a shared radio frequency spectrum band, and generating, based at least in part on the configuration of the downlink subframe, a cell-specific reference signal (CRS) for the downlink subframe. A second method includes dynamically determining a presence of a CRS in a downlink subframe in a shared radio frequency spectrum band, and performing at least one operation during the downlink subframe in response to the dynamic determination.

First claim

What is claimed is:

1 . A method for wireless communication, comprising:
identifying a configuration of a downlink subframe in a shared radio frequency spectrum band; and generating, based at least in part on the configuration of the downlink subframe, a cell-specific reference signal (CRS) for the downlink subframe.

2 . The method of claim 1 , further comprising:
signaling a presence of the CRS in the downlink subframe.

3 . The method of claim 2 , wherein signaling the presence of the CRS comprises:
signaling the presence of the CRS in downlink control information (DCI) included in a physical downlink control channel (PDCCH) or an enhanced PDCCH (ePDCCH) on a first carrier; and transmitting the signaling on a licensed carrier or an unlicensed carrier, wherein the licensed carrier and the unlicensed carrier are different from the first carrier.

4 . The method of claim 1 , further comprising:
transmitting, in a first set of at least one symbol period comprising a first symbol period of the downlink subframe, a control region comprising a physical control format indicator channel (PCFICH), a physical frame format indicator channel (PFFICH), a physical downlink control channel (PDCCH), or a physical hybrid automatic repeat request indicator channel (PHICH); and transmitting the CRS in the first symbol period of the downlink subframe.

5 . The method of claim 4 , wherein the first set of at least one symbol period includes at least a second symbol period of the downlink subframe, and wherein the control region is further transmitted in at least the second symbol period of the downlink subframe.

6 . The method of claim 5 , further comprising:
increasing an aggregation level in at least the second symbol period to satisfy a minimum bandwidth occupancy.

7 . The method of claim 5 , further comprising:
transmitting a filler symbol over at least one tone in at least the second symbol period to satisfy a minimum bandwidth occupancy.

8 . The method of claim 7 , wherein the filler symbol comprises a junk symbol.

9 . The method of claim 5 , further comprising:
boosting a transmit power in the at least second symbol period to maintain a constant transmit power from the first symbol period to the at least second symbol period.

10 . The method of claim 9 , wherein boosting the transmit power comprises:
transmitting a filler symbol over at least one tone in at least the second symbol period.

11 . The method of claim 4 , further comprising:
transmitting, in a second set of at least one symbol period following the first set of at least one symbol period, a data region; and boosting a transmit power in at least one symbol period in the first set to maintain a constant transmit power from the first set to the second set.

12 . The method of claim 1 , wherein the downlink subframe comprises a transmission of a physical control format indicator channel (PCFICH), the method further comprising:
transmitting in the PCFICH an indication of whether a base station will be active in a next downlink subframe subsequent to the downlink subframe.

13 . The method of claim 1 , wherein the downlink subframe comprises a transmission of a physical frame format indicator channel (PFFICH), the method further comprising:
winning contention for access to the shared radio frequency spectrum band; and transmitting the downlink subframe following the winning contention for access to the shared radio frequency spectrum band.

14 . The method of claim 1 , wherein the downlink subframe comprises a transmission of a physical hybrid automatic repeat request indicator channel (PHICH), the method further comprising:
transmitting in the PHICH a group acknowledgement for a group of uplink subframes received from a user equipment (UE).

15 . The method of claim 14 , further comprising:
transmitting the group acknowledgement with a set of cyclic redundancy check (CRC) bits.

16 . The method of claim 1 , wherein the downlink subframe comprises a transmission of a first physical hybrid automatic repeat request indicator channel (PHICH), the method further comprising:
transmitting in the first PHICH a first group acknowledgement for a first group of uplink subframes received from a first user equipment (UE); and transmitting in a second PHICH, in a second downlink subframe, a second group acknowledgement for a second group of uplink subframes received from a second UE; wherein the first group of uplink subframes is received for a different time domain duplexing (TDD) frame structure than the second group of uplink subframes.

17 . The method of claim 1 , wherein the downlink subframe comprises a transmission of a physical hybrid automatic repeat request indicator channel (PHICH), the method further comprising:
allocating at least one resource for the PHICH as a function of a user equipment (UE) grant starting resource block and an identifier of an uplink subframe.

18 . The method of claim 1 , wherein the downlink subframe comprises a CRS-based enhanced system information block (eSIB).

19 . The method of claim 18 , wherein the downlink subframe comprises a downlink clear channel assessment exempt transmission (D-CET) subframe.

20 . The method of claim 18 , wherein the CRS-based eSIB comprises one of a plurality of eSIBs transmitted on a periodic basis.

21 . The method of claim 1 , wherein the downlink subframe comprises at least one of: a data transmission for a user equipment (UE), the data transmission based at least in part on a space frequency block coding (SFBC); a CRS-based channel quality indicator (CQI) measurement subframe; a transmission of a common search space grant in a self-scheduling mode; a transmission of a physical control format indicator channel (PCFICH); a transmission of a physical frame format indicator channel (PFFICH); a transmission of a physical downlink control channel (PDCCH); a transmission of a physical hybrid automatic repeat request indicator channel (PHICH); or a transmission of a physical broadcast channel (PBCH).

22 . An apparatus for wireless communication, comprising:
a processor; memory in electronic communication with the processor; and the processor and memory configured to:
identify a configuration of a downlink subframe in a shared radio frequency spectrum band; and
generate, based at least in part on the configuration of the downlink subframe, a cell-specific reference signal (CRS) for the downlink subframe.

23 . A method for wireless communication, comprising:
dynamically determining a presence of a cell-specific reference signal (CRS) in a downlink subframe in a shared radio frequency spectrum band; and performing at least one operation during the downlink subframe in response to the dynamic determination.

24 . The method of claim 23 , wherein performing the at least one operation during the downlink subframe comprises:
performing a measurement on the CRS to obtain a channel estimation; and decoding, based at least in part on the channel estimation, at least one of: a physical control format indicator channel (PCFICH), a physical frame format indicator channel (PFFICH), a physical downlink control channel (PDCCH), a physical hybrid automatic repeat request indicator channel (PHICH), or a physical broadcast channel (PBCH).

25 . The method of claim 23 , wherein dynamically determining the presence of the CRS comprises at least one of: i

Assignees

• Qualcomm Inc

Inventors

• Yerramalli Srinivas
• Luo Tao
• Malladi Durga Prasad
• Wei Yongbin

Classifications

• H04L5/0048 Primary

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04W24/08

  Testing, {supervising or monitoring} using real traffic · CPC title

• H04L5/0035

  Resource allocation in a cooperative multipoint environment · CPC title

• H04L5/005

  of common pilots, i.e. pilots destined for multiple users or terminals · CPC title

• H04L1/1822

  involving configuration of automatic repeat request [ARQ] with parallel processes · CPC title