Time and frequency synchronization for LTE-advanced new carrier type

Patent metadata

Field	Value
Publication number	US-9356979-B2
Application number	US-201213537271-A
Country	US
Kind code	B2
Filing date	Jun 29, 2012
Priority date	Jan 27, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A particular kind of component carrier that may be used as a secondary cell in an LTE system is a new type carrier that has reduced or eliminated legacy control signaling such as the omission of CRSs. Alternative techniques are described for performing timing and frequency synchronization in the downlink between an eNB and a UE when CRSs are not present in a component carrier. These techniques involve using either channel state information reference signals or UE-specific reference signals.

First claim

What is claimed is:

1. A device for a user equipment (UE), comprising:
an RF transceiver for providing an LTE air interface for communicating with a base station operating as an enhanced/evolved Node B (eNB);
processing circuitry configured to attach to the eNB via component carriers configured as primary and secondary cells (PCells and SCells), wherein the secondary cell carrier does not include cell-specific reference signals (CRSs);
wherein the processing circuitry is further configured to receive channel state information reference signals (CSI reference signals) over the SCell carrier and further configured to use the CSI reference signals for time and frequency synchronization; and,
wherein the processing circuitry is configured to estimate a timing offset by measuring a phase shift of the CSI reference signals across different subcarrier frequencies and configured to estimate a frequency offset by measuring the phase shift of the CSI reference signals at different times.

2. The device of claim 1 wherein the processing circuitry is configured to receive the CSI reference signals mapped to specified resource elements every one, two, three, or four subframes for Type 1 frame structures and to receive the CSI reference signals mapped to specified resource elements every five subframes with subframe offsets selected from (0,3,4), (0,3) (0,4), or (3,4) for Type 2 frame structures.

3. The device of claim 1 wherein the processing circuitry is configured to receive two CSI reference signals contained within specified subframes used by the eNB to transmit CSI reference signals.

4. The device of claim 1 wherein the processing circuitry is configured to:
receive OFDM symbols with a normal cyclic prefix;
receive the CSI reference signals in subframes designated for carrying CSI reference signals with the CSI reference signals mapped to resource elements (k,l), where k and l are indices in the frequency and time domain, respectively, wherein:
k=k′+m+0 for antenna ports p 15 and p 16 ,
k=k′+m+−6 for antenna ports p 17 and p 18 ,
k=k′+m+−1 for antenna ports p 19 and p 20 ,
k=k′+m+−7 for antenna ports p 21 and p 22 ,
m=0, 1, . . . N RB −1, where N RB is the number of resource blocks in a downlink slot,
l=l′+l″,
l″=0, 1; and,

receive CSI reference signals in a CSI configuration selected from the following:
1) (k′,l′)=(9,5) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 , (k′,l′)=(9,5) in each slot of a subframe designated to carry CSI reference signals using four antenna ports p 15 through p 18 , and (k′,l′)=(9,5) in each slot of a subframe designated to carry CSI reference signals using eight antenna ports p 15 through p 22 ;
2) (k′,l′)=(8,5) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 , (k′,l′)=(8,5) in each slot of a subframe designated to carry CSI reference signals using four antenna ports p 15 through p 18 ;
3) (k′,l′)=(3,5) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 ;
4) (k′,l′)=(2,5) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 ;
5) (k′,l′)=(9,5) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 , (k′,l′)=(9,5) in each slot of a subframe designated to carry CSI reference signals using four antenna ports p 15 through p 18 , and (k′,l′)=(9,5) in the first slot only of a subframe designated to carry CSI reference signals using eight antenna ports p 15 through p 22 ;
6) (k′,l′)=(9,5) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 , (k′,l′)=(9,5) in the first slot only of a subframe designated to carry CSI reference signals using four antenna ports p 15 through p 18 , and (k′,l′)=(9,5) in the first slot only of a subframe designated to carry CSI reference signals using eight antenna ports p 15 through p 22 ; or,
7) (k′,l′)=(8,5) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 , and (k′,l′)=(8,5) in the first slot only of a subframe designated to carry CSI reference signals using four antenna ports p 15 through p 18 .

5. The device of claim 4 wherein the processing circuitry is configured to receive the CSI reference signals mapped to specified resource elements every one, two, three, or four subframes for Type 1 frame structures and to receive the CSI reference signals mapped to specified resource elements every five subframes with subframe offsets selected from (0,3,4), (0,3) (0,4), or (3,4) for Type 2 frame structures.

6. The device of claim 1 wherein the processing circuitry is configured to:
receive OFDM symbols with an extended cyclic prefix;
receive the CSI reference signals in subframes designated for carrying CSI reference signals with the CSI reference signals mapped to resource elements (k,l), where k and l are indices in the frequency and time domain, respectively, wherein:
k=k′+m+0 for antenna ports p 15 and p 16 ,
k=k′+m+−3 for antenna ports p 17 and p 18 ,
k=k′+m+−6 for antenna ports p 19 and p 20 ,
k=k′++−9 for antenna ports p 21 and p 22 ,
m=0, 1, . . . N RB −1, where N RB is the number of resource blocks in a downlink slot,
l=l′+l″,
l″=0, 1; and,

receive CSI reference signals in a CSI configuration selected from the following:
1) (k′,l′)=(9,4) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 , (k′,l′)=(9,4) in each slot of a subframe designated to carry CSI reference signals using four antenna ports p 15 through p 18 , and (k′,l′)=(9,4) in each slot of a subframe designated to carry CSI reference signals using eight antenna ports p 15 through p 22 ;
2) (k′,l′)=(3,4) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 , (k′,l′)=(3,4) in each slot of a subframe designated to carry CSI reference signals using four antenna ports p 15 through p 18 ;
3) (k′,l′)=(6,4) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 ;
4) (k′,l′)=(0,4) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 ;
5) (k′,l′)=(9,4) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 , (k′,l′)=(9,4) in each slot of a subframe designated to carry CSI reference signals using four antenna ports p 15 through p 18 , and (k′,l′)=(9,4) in the first slot only of a subframe designated to carry CSI reference signals using eight antenna ports p 15 through p 22 ;
6) (k′,l′)=(9,4) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 , (k′,l′)=(9,4) in the first slot only of a subframe designated to carry CSI reference signals using four antenna ports p 15 through p 18 , and (k′,l′)=(9,4) in the first slot only of a subframe designated to carry CSI reference signals using eight antenna ports p 15 through p 22 ; or,
7) (k′,l′)=(3,4) in each slot of a subframe designated to carry CSI reference signals using two antenna ports p 15 and p 16 , and (k′,l′)=(3,4) in the first slot only of a subframe designated to carry CSI reference signals using four antenna ports p 15 through p 18 .

7. The device of claim 6 wherein the processing circuitry is configured to receive the CSI reference signals mapped to specified resource elements every one, two, three, or four subframes for Type 1 frame structures and to receive the CSI reference signals mapped to specified resource elements every five sub

Assignees

• Bashar Shafi
• He Hong
• Niu Huaning
• Fwu Jong-Kae
• Zhu Yuan
• Chen Xiaogang
• Intel Corp

Inventors

• Bashar Shafi
• He Hong
• Niu Huaning
• Fwu Jong-Kae
• Zhu Yuan
• Chen Xiaogang

Classifications

• H04W72/20

  Control channels or signalling for resource management · CPC title

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W72/53

  based on regulatory allocation policies · CPC title

• H04W72/542

  using measured or perceived quality · CPC title

• H04W72/541

  using the level of interference · CPC title