INTERFERENCE CANCELLATION METHOD, DATA SENDING METHOD, AND APPARATUSES IN LONG TERM EVOLUTION SYSTEM

• US 20150078257A1
• Filed: 11/25/2014
• Published: 03/19/2015
• Est. Priority Date: 05/25/2012
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Wu, Tong, Xiao, Dengkun, Wei, Jingxin
• Granted Patent: US 9,532,244 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04J 11/0036 at the receiver
• CPC Class Codes: H04J 11/0093 Neighbour cell search
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition

Abstract

An interference cancellation method, data sending method, apparatus, user equipment and base station in a Long Term Evolution system are disclosed. The interference cancellation method includes: obtaining downlink cell-specific power ratio information of a specific cell; performing channel estimation based on a downlink cell-specific reference signal (CRS) of the specific cell, to obtain a channel estimation matrix of a specific physical channel, signal, or message of the specific cell; compensating the channel estimation matrix by using the downlink cell-specific power ratio information; and canceling, in an original signal that is received from a target cell and is interfered by the specific cell, interference caused by the specific cell in a received signal from a specific physical channel, signal, or message. A technical problem in the prior art that a user equipment cannot effectively cancel interference because power transmission strength of a strong interfering cell cannot be correctly estimated is solved.

Claims

1. An interference cancellation method in a Long Term Evolution system, the method comprising:

obtaining downlink cell-specific power information of a specific cell, wherein the specific cell is a neighboring cell or a serving cell;

performing channel estimation based on a downlink cell-specific reference signal (CRS) of the specific cell, to obtain a channel estimation matrix of a specific physical channel, signal, or message of the specific cell;

compensating the channel estimation matrix by using the downlink cell-specific power information of the specific cell, to obtain a new channel estimation matrix;

reconstructing a received signal from the specific physical channel, signal, or message of the specific cell according to the new channel estimation matrix; and

canceling, in an original signal received from a target cell, interference caused by the specific cell, which is not the target cell, in a received signal from a specific physical channel, signal, or message, wherein the target cell is a serving cell or a neighboring cell.

2. The method according to claim 1, wherein the downlink cell-specific power information comprises:

a power ratio factor or a power difference factor between transmit power of the specific physical channel, signal, or message and transmit power of the CRS;

or

a power ratio factor or a power difference factor between transmit power of the CRS and transmit power of the specific physical channel, signal, or message.

3. The method according to claim 1, wherein:

the specific physical channel comprises;

a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), a physical broadcast channel (PBCH), or a paging channel (PCH);

the specific message comprises;

a system information block (SIB) message; and

the specific signal comprises;

a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

4. The method according to claim 1, wherein obtaining downlink cell-specific power information of a specific cell comprises:

receiving the downlink cell-specific power information of the specific cell, which is unicast on a network side by using a radio resource control (RRC) message;

or

receiving the downlink cell-specific power information of the specific cell and a physical cell identifier of the specific cell, which are unicast on a network side by using an RRC message;

or

receiving the downlink cell-specific power information of the specific cell, or the downlink cell-specific power information and a physical cell identifier of the specific cell, broadcast on a network side by using a physical broadcast channel (PBCH);

or

receiving a system information block (SIB) message broadcast on a network side, wherein the SIB message comprises;

the downlink cell-specific power information of the specific cell, or the downlink cell-specific power information and a physical cell identifier of the specific cell.

5. The method according to claim 1, wherein the specific cell is an intra-frequency neighboring cell.

6. The method according to claim 5, wherein the downlink cell-specific power information comprises:

a power ratio factor or a power difference factor between transmit power of the specific physical channel, signal, or message and transmit power of the CRS;

or

a power ratio factor or a power difference factor between transmit power of the CRS and transmit power of the specific physical channel, signal, or message.

7. The method according to claim 5, wherein:

the specific physical channel comprises;

a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), a physical broadcast channel (PBCH), or a paging channel (PCH);

the specific message comprises;

a system information block (SIB) message; and

the specific signal comprises;

a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

8. An interference cancellation apparatus in a Long Term Evolution system, the apparatus comprising:

an obtaining unit, configured to obtain downlink cell-specific power information of a specific cell, wherein the specific cell comprises a neighboring cell or a serving cell;

an estimating unit, configured to perform channel estimation based on a downlink cell-specific reference signal (CRS) of the specific cell, to obtain a channel estimation matrix of a specific physical channel, signal, or message of the specific cell;

a compensating unit, configured to compensate the channel estimation matrix by using the downlink cell-specific power information of the specific cell, to obtain a new channel estimation matrix;

a reconstructing unit, configured to reconstruct a received signal from the specific physical channel, signal, or message of the specific cell according to the new channel estimation matrix; and

an interference cancellation unit, configured to cancel, in an original signal received from a target cell, interference caused by the intra-frequency specific cell, which is not the target cell, in a received signal from a specific physical channel, signal, or message, wherein the target cell comprises a serving cell or a neighboring cell.

9. The apparatus according to claim 8, wherein the downlink cell-specific power information comprises:

a power ratio factor or a power difference factor between transmit power of the specific physical channel, signal, or message and transmit power of the CRS;

or

a power ratio factor or a power difference factor between transmit power of the CRS and transmit power of the specific physical channel, signal, or message.

10. The apparatus according to claim 8, wherein the obtaining unit comprises:

a first receiving unit, configured to receive the downlink cell-specific power information of the specific cell, which is unicast on a network side by using a radio resource (RRC) message;

or

a second receiving unit, configured to receive the downlink cell-specific power information of the specific cell and a physical cell identifier of the specific cell, which are unicast on a network side by using an RRC message;

or

a third receiving unit, configured to receive the downlink cell-specific power information of the specific cell, or the downlink cell-specific power information and a physical cell identifier of the specific cell, broadcast on a network side by using a physical broadcast channel (PBCH);

or

a fourth receiving unit, configured to receive a system information block (SIB) message broadcast on a network side, wherein the SIB message comprises;

the downlink cell-specific power information of the specific cell, or the downlink cell-specific power information and a physical cell identifier of the specific cell.

11. The apparatus according to claim 8, wherein the specific cell is an intra-frequency neighboring cell.

12. The apparatus according to claim 11, wherein the downlink cell-specific power information comprises:

a power ratio factor or a power difference factor between transmit power of the specific physical channel, signal, or message and transmit power of the CRS;

or

a power ratio factor or a power difference factor between transmit power of the CRS and transmit power of the specific physical channel, signal, or message.

13. The apparatus according to claim 11, wherein the obtaining unit comprises:

a first receiving unit, configured to receive the downlink cell-specific power information of the specific cell, which is unicast on a network side by using a radio resource control (RRC) message;

or

a second receiving unit, configured to receive the downlink cell-specific power information of the specific cell and a physical cell identifier of the specific cell, which are unicast on a network side by using an RRC message;

or

a third receiving unit, configured to receive the downlink cell-specific power information of the specific cell, or the downlink cell-specific power information and a physical cell identifier of the specific cell, broadcast on a network side by using a physical broadcast channel (PBCH);

or

a fourth receiving unit, configured to receive a system information block (SIB) message broadcast on a network side, wherein the SIB message comprises;

the downlink cell-specific power information of the specific cell, or the downlink cell-specific power information and a physical cell identifier of the specific cell.

14. A data sending apparatus in a Long Term Evolution system, the apparatus comprising:

an obtaining unit, configured to obtain downlink cell-specific power information of a specific cell, or obtain downlink cell-specific power information and a physical cell identifier of a specific cell;

an adding unit, configured to add the downlink cell-specific power information of the specific cell, or the downlink cell-specific power information of the specific cell and the physical cell identifier of the specific cell to a radio resource control (RRC) message, or add the downlink cell-specific power information of the specific cell to a broadcast message; and

a sending unit, configured to unicast the RRC message or broadcast the broadcast message to a user terminal, so that the user terminal that receives the RRC message or the broadcast message performs interference cancellation.

15. The apparatus according to claim 14, wherein the sending unit comprises:

a first unicast unit, configured to unicast the downlink cell-specific power information of the specific cell by using a radio resource control information element in the RRC message;

or

a second unicast unit, configured to unicast the downlink cell-specific power information of the specific cell and the physical cell identifier of the specific cell by using a radio resource control information element or a measurement information element in the RRC message;

or

a first broadcast unit, configured to broadcast the downlink cell-specific power information, or the downlink cell-specific power information and the physical cell identifier of the specific cell to the user terminal by using a system master information block (MIB) carried on a physical broadcast channel (PBCH);

or

a second broadcast unit, configured to broadcast the downlink cell-specific power information, or the downlink cell-specific power information and the physical cell identifier of the specific cell to the user terminal by using a system information block (SIB) message.

16. The apparatus according to claim 14 wherein the downlink cell-specific power information comprises:

a power ratio factor or a power difference factor between transmit power of a specific physical channel, signal, or message and transmit power of a reference signal (CRS);

or

a power ratio factor or a power difference factor between transmit power of a reference signal (CRS) and transmit power of a specific physical channel, signal, or message.

17. The apparatus according to claim 14, wherein the obtaining unit comprises:

a first obtaining unit, configured to obtain downlink cell-specific power information of a specific cell of an opposite party or obtain downlink cell-specific power information and a physical cell identifier of a specific cell of the specific cell or the serving cell by using a logical interface to the specific cell or the serving cell;

or

a second obtaining unit, configured to obtain the downlink cell-specific power information of the specific cell or obtain the downlink cell-specific power information and the physical cell identifier of the specific cell by using load information;

or

a third obtaining unit, configured to obtain the downlink cell-specific power information of the specific cell or obtain the downlink cell-specific power information and the physical cell identifier of the specific cell by using load information transmitted by a logical interface.

18. The apparatus according to claim 14, wherein the specific cell is an intra-frequency neighboring cell.

19. The apparatus according to claim 18, wherein the downlink cell-specific power information comprises:

a power ratio factor or a power difference factor between transmit power of a specific physical channel, signal, or message and transmit power of a reference signal (CRS);

or

a power ratio factor or a power difference factor between transmit power of a reference signal (CRS) and transmit power of a specific physical channel, signal, or message.

20. The apparatus according to claim 16, wherein the obtaining unit comprises:

a first obtaining unit, configured to obtain downlink cell-specific power information of a specific cell of an opposite party or obtain downlink cell-specific power information and a physical cell identifier of a specific cell of the specific cell or the serving cell by using a logical interface to the specific cell or the serving cell;

or

a second obtaining unit, configured to obtain the downlink cell-specific power information of the specific cell or obtain the downlink cell-specific power information and the physical cell identifier of the specific cell by using load information;

or

a third obtaining unit, configured to obtain the downlink cell-specific power information of the specific cell or obtain the downlink cell-specific power information and the physical cell identifier of the specific cell by using load information transmitted by a logical interface.