METHOD AND APPARATUS FOR OBTAINING CHANNEL STATE INFORMATION

• US 20140133340A1
• Filed: 01/17/2014
• Published: 05/15/2014
• Est. Priority Date: 07/20/2011
• Status: Active Grant

• Current Assignee: Honor Device Company Limited
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Zhou, Mingyu, Zhou, Yongxing, Xia, Liang, Ren, Xiaotao
• Granted Patent: US 9,503,336 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 43/08 Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters
• CPC Class Codes: H04L 43/50 Testing arrangements
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 48/00 Access restriction access security to prevent unauthorised access H04W12/08; Network selection; Access point selection

Abstract

This invention discloses method and apparatus for obtaining channel state information, and relates to the field of communication techniques, capable of reducing signaling and feedback overheads and lowering UE operation complexity. According to the solutions provided in embodiments of this invention, a RS predetermined transmission time and a RS predetermined frequency are transmitted to a UE by any one cell of at least two cells; each cell or cell group out of the at least two cells, according to the RS predetermined transmission time and the RS predetermined frequency, transmits a RS to the UE on different RS resources; the measurement result transmitted by the UE is received, which comprises CSI between any one cell or cell group out of at least two cells and the UE. The solutions provided in embodiments of this invention are applicable when it is required to obtain CSI between multiple cells and a UE.

Claims

1. A method for obtaining channel state information, comprising:

transmitting, from any one cell of at least two cells, a RS predetermined time and a RS predetermined frequency to a UE;

according to the RS predetermined transmission time and the RS predetermined frequency, transmitting a RS to the UE through different RS resources by each cell or cell group out of the at least two cells, to enable the UE to measure the RS received on the different RS resources sequentially according to the RS predetermined transmission time and the RS predetermined frequency;

receiving the measurement result transmitted by the UE, the measurement result comprising channel state information CSI between any one cell or cell group out of at least two cells and the UE.

2. The method for obtaining channel state information according to claim 1, wherein, before transmitting a RS to the UE through different RS resources by each cell or cell group out of the at least two cells according to the RS predetermined transmission time and the RS predetermined frequency, further comprising:

obtaining identical RS sequence information and sending it to the UE, wherein the RS sequence information is used to generate the RS.

3. The method for obtaining channel state information according to claim 2, wherein obtaining identical RS sequence information comprises:

obtaining the identical RS sequence information from a serving cell of the UE, wherein a cell sending signaling to the UE through a Physical Downlink Control Channel PDCCH is the serving cell;

or

obtaining the identical RS sequence information through an interface between the at least two cells;

or

determining the identical RS sequence information by the at least two cells respectively.

4. The method for obtaining channel state information according to claim 1, wherein when each cell of the at least two cells transmits a RS to the UE on different RS resources according to the RS predetermined transmission time and the RS predetermined frequency, on the RS resource on which a first cell transmits the RS to the UE according to the RS predetermined transmission time and the RS predetermined frequency, other cells except for the first cell of the at least two cells do not transmit the RS to the UE according to the RS predetermined transmission time and the RS predetermined frequency, wherein the first cell is any one cell of the at least two cells.

5. The method for obtaining channel state information according to claim 4, wherein not transmitting the RS to the UE according to the RS predetermined transmission time and the RS predetermined frequency comprises:

other cells except for the first cell of the at least two cells do not transmit signal at the RS predetermined transmission time and the RS predetermined frequency.

6. The method for obtaining channel state information according to claim 5, wherein the number of the RS predetermined transmission time and the RS predetermined frequency is computed according to the total number of all RS predetermined transmission times and RS predetermined frequencies, a RS resource number, a cell ID, the total number of cells transmitting the RS to the UE, and some or all references of a random sequence.

7. The method for obtaining channel state information according to claim 6, wherein the number of the RS predetermined transmission time and the RS predetermined frequency is computed according to Pattern_ID=(Cell_ID+N_TTI)mod M;

or Pattern_ID=(Cell_ID+N_TTI) mod N_cell;

or Pattern_ID=(Cell_ID+N_TTI+c(N_TTI)) mod N_cell;

or Pattern_ID=(Cell_ID+·

└

N_TTI/(K×

P_FB)┘

) mod N_cell;

or Pattern_ID=(Cell_ID+·

└

N_TTI/K×

N_rank┘

) mod N_cell;

Wherein, Pattern_ID represents the number of the RS predetermined transmission time and the RS predetermined frequency used for transmitting the RS;

Cell_ID represents the ID of the cell transmitting the RS;

N_TTI represents the number of the TTI on which the RS is transmitted;

mod represents modulus operation;

N_cell represents the number of cells transmitting the RS;

c(N_TTI) represents a random sequence;

P_FB represents the cycle of CSI feedback of the UE;

K represents a natural number, └

.┘

represents rounding-down operation;

N_rank represents the number of cycles of transmitting the RS required by the UE to feed back one rank indicator RI.

8. The method for obtaining channel state information according to claim 1, wherein, after transmitting a RS to the UE through different RS resources by each cell or cell group out of the at least two cells according to the RS predetermined transmission time and the RS predetermined frequency, further comprising:

setting a filtering coefficient to 0;

transmitting the filtering coefficient and the filtering cycle to the UE, to enable the UE to perform filtering on the CSI between any one cell or cell group out of at least two cells and the UE obtained by the UE through measuring the RS.

9. A method for obtaining channel state information, comprising:

receiving a RS predetermined transmission time and a RS predetermined frequency transmitted by any one cell of at least two cells;

receiving a RS transmitted on different RS resources, and on the different RS resources, sequentially measuring the RS according to the RS predetermined time and the RS predetermined frequency, to obtain CSI between the at least two cells and the UE;

transmitting the measurement result to the any one cell of the at least two cells, the measurement result comprising CSI between any one cell or cell group out of at least two cells and the UE.

10. The method for obtaining channel state information according to claim 9, wherein, before receiving a RS transmitted by any one cell or cell group out of at least two cells on different RS resources, further comprising:

receiving identical RS sequence information transmitted from the any one cell or cell group out of at least two cells, wherein the identical RS sequence information is used to generate the RS.

11. The method for obtaining channel state information according to claim 10, wherein, after receiving a RS transmitted by any one cell or cell group out of at least two cells on different RS resources, further comprising:

receiving a filtering coefficient and a filtering cycle transmitted by any one cell of the at least two cells and performing filtering on the CSI between any one cell or cell group out of at least two cells and the UE obtained through measuring the RS, wherein the filtering coefficient is 0.

12. An apparatus for obtaining channel state information, a UE is served by at least two cells, the apparatus for obtaining channel state information is an apparatus in any one cell of the at least two cells, the apparatus comprising:

a transmission unit, for transmitting a RS predetermined time and a RS predetermined frequency to the UE;

a reference signal transmission unit, according to the RS predetermined transmission time and the RS predetermined frequency, for transmitting a RS to the UE on RS resources, to enable the UE to measure the RS received on the different RS resources sequentially according to the RS predetermined transmission time and the RS predetermined frequency, wherein the RS resources used by the at least two cells serving the UE when transmitting the RS to the UE according to the RS predetermined transmission time and the RS predetermined frequency are different RS resources;

a receiving unit, for receiving the measurement result transmitted by the UE, the measurement result comprising CSI between any one cell or cell group out of at least two cells and the UE.

13. The apparatus for obtaining channel state information according to claim 12, wherein the apparatus further comprises:

an execution unit, for obtaining identical RS sequence information and sending it to the UE, wherein the RS sequence information is used to generate the RS.

14. The apparatus for obtaining channel state information according to claim 13, wherein the execution unit is particularly used to:

obtaining the identical RS sequence information from a serving cell of the UE, wherein the serving cell is a cell sending signaling to the UE through a Physical Downlink Control Channel PDCCH;

or

obtaining the identical RS sequence information through an interface between the at least two cells;

or

determining the identical RS sequence information by the at least two cells respectively.

15. The apparatus for obtaining channel state information according to claim 12, wherein the reference signal transmission unit is further used to:

on the RS resource on which a first cell transmits the RS to the UE according to the RS predetermined transmission time and the RS predetermined frequency, transmit no RS to the UE according to the RS predetermined transmission time and the RS predetermined frequency, wherein the apparatus the reference signal transmission unit is located in belongs to a cell different to the first cell, and the first cell is any one cell of the at least two cells.

16. The apparatus for obtaining channel state information according to claim 12, wherein the reference signal transmission unit is further used to:

on the RS resource on which the first cell transmits the RS to the UE according to the RS predetermined transmission time and the RS predetermined frequency, transmit no signal at the RS predetermined transmission time and the RS predetermined frequency.

17. The apparatus for obtaining channel state information according to claim 16, wherein the apparatus further comprises:

a computing unit, for computing the number of the RS predetermined transmission time and the RS predetermined frequency according to the total number of all RS predetermined transmission times and RS predetermined frequencies, a RS resource number, a cell ID, the total number of cells transmitting the RS to the UE, and some or all references of a random sequence.

18. The apparatus for obtaining channel state information according to claim 17, wherein the computing unit is particularly used to compute the number of the RS predetermined transmission time and the RS predetermined frequency according to Pattern_ID=(Cell_ID+N_TTI)mod M;

or Pattern_ID=(Cell_ID+N_TTI) mod N_cell;

or Pattern_ID=(Cell_ID+N_TTI+c(N_TTI)) mod N_cell;

or Pattern_ID=(Cell_ID+·

└

N_TTI/(K×

P_FB)┘

) mod N_cell;

or Pattern_ID=(Cell_ID+·

└

N_TTI/K×

N_rank┘

) mod N_cell;

Wherein, Pattern_ID represents the number of the RS predetermined transmission time and the RS predetermined frequency used for transmitting the RS;

Cell_ID represents the ID of the cell transmitting the RS;

N_TTI represents the number of the TTI on which the RS is transmitted;

mod represents modulus operation;

N_cell represents the number of cells transmitting the RS;

c(N_TTI) represents a random sequence;

P_FB represents the cycle of CSI feedback of the UE;

K represents a natural number, └

.┘

represents rounding-down operation;

N_rank represents the number of cycles of transmitting the RS required by the UE to feed back one rank indicator RI.

19. The apparatus for obtaining channel state information according to claim 12, wherein the apparatus further comprises:

a setting unit, for setting a filtering coefficient to 0;

a filtering signal transmission unit, for transmitting the filtering coefficient and the filtering cycle to the UE, to enable the UE to perform filtering on the CSI between any one cell or cell group out of at least two cells and the UE obtained by the UE through measuring the RS.

20. An apparatus for obtaining channel state information, comprising:

a first receiving unit, for receiving a RS predetermined time and a RS predetermined frequency transmitted by any one cell of at least two cells;

a reference signal receiving unit, for receiving a RS transmitted on different RS resources, and on the different RS resources, sequentially measuring the RS according to the RS predetermined time and the RS predetermined frequency, to obtain CSI between the at least two cells and the UE;

a transmission unit, for transmitting the measurement result to any one cell of the at least two cells, the measurement result comprising CSI between any one cell or cell group out of at least two cells and the UE.

21. The apparatus for obtaining channel state information according to claim 20, wherein the apparatus further comprises:

a second receiving unit, for receiving identical RS sequence information transmitted from the any one cell or cell group out of at least two cells, wherein the identical RS sequence information is used to generate the RS.

22. The apparatus for obtaining channel state information according to claim 21, wherein the apparatus further comprises:

a filtering signal receiving unit, for receiving a filtering coefficient and a filtering cycle transmitted by any one cell of the at least two cells and performing filtering on the CSI between any one cell or cell group out of at least two cells and the UE obtained through measuring the RS, wherein the filtering coefficient is 0.