WO2013068832A1

WO2013068832A1 - Methods and apparatuses for interference suppression for user equipment in heterogeneous network

Info

Publication number: WO2013068832A1
Application number: PCT/IB2012/002420
Authority: WO
Inventors: Qi JIANG; Jianguo Liu; Zheng Liu; Gang A SHEN
Original assignee: Alcatel Lucent
Priority date: 2011-11-07
Filing date: 2012-10-30
Publication date: 2013-05-16
Also published as: CN103096374A; TW201328390A; CN103096374B

Abstract

Embodiments of the present invention provide a method for interference suppression for a user equipment in a heterogeneous network, wherein the heterogeneous network comprises a Macro base station and a low power node, the user equipment is served by the low power node, and the low power node transmits data to the user equipment on a predefined resource block. The method may comprise the steps of: receiving a measurement report from the user equipment; determining a Tx muted resource element in the resource block based on the measurement report; and notifying the user equipment to perform rate matching, so that the user equipment receives data transmitted on the resource block according to a performing result of the rate matching.

Description

METHODS AND APPARATUSES FOR INTERFERENCE SUPPRESSION FOR USER EQUIPMENT IN HETEROGENEOUS NETWORK

FIELD OF THE INVENTION

[0001] The present invention relates to the field of communication, and more specifically to methods and apparatuses for interference suppression for a user equipment in a heterogeneous network.

BACKGROUND OF THE INVENTION

[0002] Heterogeneous networks (HetNets) are a technology for increasing system throughput and network overall efficiency. In heterogeneous networks, low power nodes (LPNs) are deployed in Macrocell coverage areas to form a heterogeneous network comprising different node types under the same coverage. Low power nodes are, for example, Pico base stations, Femto/Home base stations, Micro base stations, remote radio heads (RRHs), relays, etc. Currently, common heterogeneous network scenarios are, for example, indoor Femto/Home base stations, outdoor hotspots, indoor hotspots, etc.

[0003] An important part in heterogeneous networks is interference between various nodes under the same coverage. In heterogeneous networks, the transmission power of Macro base stations is typically much higher than that of a low power node, thus the user equipment at the cell edge of the low power node often suffer from worse signal quality because of weaker signals and/or interference from signals of other cell.

[0004] During LTE Release 10 (i.e., LTE-Advanced, referred to as LTE-A for short), a discussion has been held for the inter-cell interference cancellation (elCIC) technology for heterogeneous networks, and the almost blank subframe (ABS) with reduced power and reduced activities has been applied in Macrocells to suppress or alleviate the interference on low power node cells such as Picocells and the like.

[0005] However, in order to ensure backward compatibility with user equipment (UE), the cell reference signals (CRSs) on Macrocells are still transmitted no matter a subframe is configured to be the above almost blank subframe or not. Hence, the cell reference signals of Macrocells might always interfere with data transmission in Picocells (such as data transmission over the physical downlink shared channel (PDSCH)).

[0006] During 3 GPP RANI discussion, the transmission (Tx) muting on Picocells combined with UE rate matching has been proposed as a solution for interference suppression. However, in order to realize this solution, both the Picocell and Pico UE need to know resource elements (REs), in a resource block (RB) for data transmission, on which data transmission is muted due to suffering serious interference from Macrocell's CRS interference. Besides, the Pico UE also needs to know when to switch on the rate matching corresponding to Tx muting. All these problems require further study and solution.

[0007] Therefore, there is a need in the art for a solution capable of interference suppression by Tx muting combined with UE rate matching.

SUMMARY OF THE INVENTION

[0008] In view of the above problems, the present invention provides methods and apparatuses for interference suppression for user equipment in a heterogeneous network. The methods and apparatuses of the present invention are simply implemented, use less signaling and can realize Tx muting and user equipment rate matching in a simple, high-efficiency and convenient manner, thereby completing interference suppression for user equipment served by a low power node.

[0009] According to a first aspect of the present invention, there is provided a method for interference suppression for a user equipment in a heterogeneous network, wherein the heterogeneous network comprises a Macro base station and a low power node, the user equipment is served by the low power node, and the low power node transmits data to the user equipment on a predefined resource block. The method may comprise the steps of: receiving a measurement report from the user equipment; determining a Tx muted resource element in the resource block based on the measurement report; and notifying the user equipment to perform rate matching, so that the user equipment receives data transmitted on the resource block according to a performing result of the rate matching.

[0010] According to a second aspect of the present invention, there is provided a method for interference suppression for a user equipment in a heterogeneous network, wherein the heterogeneous network comprises a Macro base station and a low power node, the user equipment is served by the low power node, and the low power node transmits data to the user equipment on a predefined resource block. The method may comprise the steps of: sending a measurement report to the low power node; in response to a notification of performing rate matching from the low power node, performing rate matching for the resource block containing a Tx muted resource element; and receiving data transmitted on the resource block according to a performing result of the rate matching.

[0011] According to a third aspect of the present invention, there is provided an apparatus for interference suppression for a user equipment in a heterogeneous network, wherein the heterogeneous network comprises a Macro base station and a low power node, the user equipment is served by the low power node, and the low power node transmits data to the user equipment on a predefined resource block. The apparatus may comprise the steps of: measurement report receiving component configured to receive a measurement report from the user equipment; determining component configured to determine a Tx muted resource element in the resource block based on the measurement report; and notifying component configured to notify the user equipment to perform rate matching, so that the user equipment receives data transmitted on the resource block according to a performing result of the rate matching.

[0012] According to a fourth aspect of the present invention, there is provided an apparatus for interference suppression for a user equipment in a heterogeneous network, wherein the heterogeneous network comprises a Macro base station and a low power node, the user equipment is served by the low power node, and the low power node transmits data to the user equipment on a predefined resource block. The apparatus may comprise the steps of: sending component configured to send a measurement report to the low power node; rate matching performing component configured to, in response to a notification of performing rate matching from the low power node, perform rate matching for the resource block containing a Tx muted resource element; and data receiving component configured to receive data transmitted on the resource block according to a performing result of the rate matching.

[0013] Other features and advantages of the present invention will become apparent from the following description of preferred embodiments illustrating the principles of the present invention, when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] As the present invention is apprehended more thoroughly, other objects and effects of the present invention will become more apparent and easier to understand from the following description with reference to the accompanying drawings, wherein:

[0015] Fig. 1 is a schematic view of a heterogeneous network according to embodiments of the present invention;

[0016] Fig. 2 is a flowchart of a method for interference suppression for user equipment in a heterogeneous network according to one embodiment of the present invention;

[0017] Fig. 3 is a flowchart of a method for interference suppression for user equipment in a heterogeneous network according to another embodiment of the present invention;

[0018] Fig. 4 is a flowchart of a method for interference suppression for user equipment in a heterogeneous network according to one embodiment of the present invention;

[0019] Fig. 5 is a flowchart of a method for interference suppression for user equipment in a heterogeneous network according to another embodiment of the present invention;

[0020] Fig. 6 is a block diagram of an apparatus for interference suppression for user equipment in a heterogeneous network according to one embodiment of the present invention; and

[0021] Fig. 7 is a block diagram of an apparatus for interference suppression for user equipment in a heterogeneous network according to another embodiment of the present invention.

[0022] Like numerals represent the same, similar or corresponding features or functions throughout the figures. DETAILED DESCRIPTION OF EMBODIMENTS

[0023] Embodiments of the present invention are now described and illustrated in more detail with reference to the accompanying drawings. It should be understood that the figures and embodiments of the present invention are only used for illustration purposes, rather than limiting the protection scope of the present invention.

[0024] The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. It is to be understood that the figures and embodiments of the present invention are for the purpose of illustration only, rather than limiting the protection scope of the present invention.

[0025] In the present invention, user equipment (UE) may be various types of terminals, such as mobile phones, personal digital assistants (PDAs), portable computers, or any other appropriate terminal with a mobile communication function. A Base station may be, for example, Node B, eNodeB (eNB), access point (AP), radio access station (RAS), etc. A Macro base station may be, for example, Macro eNodeB/eNB, which may produce a Macrocell. A Low power node may be, for example, Pico eNodeB/eNB, Pico eNodeB/eNB, Femto eNodeB/eNB, Micro eNodeB/eNB, remote radio head (RRH), relay, etc. The low power node may, for example, produce a Picocell, Femto cell, Microcell, etc.

[0026] It should be noted although the present invention mainly uses the Pico eNB as an example of low power nodes, this is merely exemplary, and any other appropriate low power nodes may be used for implementing the technical solution of the present invention.

[0027] Fig. 1 is a schematic view of a heterogeneous network which is applicable to the embodiments according to the present invention.

[0028] The communication environment shown in Fig. 1 schematically shows a heterogeneous network. This heterogeneous network schematically comprises a

Macro base station (e.g., Macro eNB) 110, a Pico base station (Pico eNB) 120, and a user equipment (UE) 130. The coverage scope of the Macro base station 110 is schematically shown as a "Macrocell," and the coverage scope of the Pico base station

120 is schematically shown as a "Picocell."

[0029] As shown in Fig. 1, the heterogeneous network includes a Macro base station 110 and a Pico base station 120, wherein the Pico base station 120 serves its user equipment 130, i.e., the Picocell 120 transmits data to the user equipment through predefined resource block(s). The user equipment 130 may hand over to the Picocell from the Macrocell and might suffer from interference from cell reference signals of the

Macrocell during communication with the Picocell 120.

[0030] In order to facilitate description, the present invention presents description based on a LTE/LTE-A system. Those skilled in the art may readily appreciate that this system is merely exemplary rather than limiting.

[0031] Fig. 2 is a flowchart of a method 200 for interference suppression for user equipment in a heterogeneous network according to one embodiment of the present invention. The heterogeneous network may be the communication environment as shown in Fig. 1, for example. The heterogeneous network may comprise a Macro base station and a low power node, the user equipment is being served by the low power node, and the low power node transmits data to the user equipment through predefined resource block(s). The method 200 shown in Fig. 2 may be executed by a low power node (e.g., a Pico base station), for example.

[0032] In step S201, a measurement report from the user equipment is received.

[0033] According to the embodiments of the present invention, the measurement report from the user equipment at least comprises: identification information of a neighboring cell causing interference on the user equipment.

[0034] In one embodiment of the present invention, the measurement report may comprise: a physical cell identifier (PCID), cell group identifier (CGI), reference signal receive power (RSRP), reference signal receive quality (RSRQ) of a neighboring cell causing interference on the user equipment.

[0035] In step S202, a Tx muted resource element in the resource block is determined based on the measurement report.

[0036] According to the embodiments of the present invention, the determination of the Tx muted resource element based on the measurement report may be implemented in various manners.

[0037] In one embodiment, a neighboring cell causing interference on the user equipment may be determined based on the measurement report; cell reference signals of the neighboring cell may be obtained; and resource elements corresponding to the cell reference signals may be determined as Tx muted resource elements.

[0038] In another embodiment, a neighboring cell causing interference on the user equipment may be determined based on the measurement report; the interference strength caused on the user equipment by the neighboring cell may be compared with a predefined threshold; the neighboring cell whose interference strength exceeds the predefined threshold may be determined as an interfering cell; cell reference signals of the interfering cell may be obtained; and resource elements corresponding to the cell reference signals may be determined as Tx muted resource elements.

[0039] In step S203, the user equipment is notified to perform rate matching so that the user equipment may receive data transmitted on the resource block, according to a performing result of the rate matching.

[0040] According to the embodiments of the present invention, it is possible to send rate matching signaling to the use equipment over the Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH) or enhanced Physical Downlink Control Channel (e-PDCCH), so as to notify the user equipment to perform rate matching. Upon receipt of the rate matching signaling, the user equipment learns that it has been notified by the Picocell to start rate matching, for the purpose of receiving data transmitted on resource block(s) according to the performing result of the rate matching.

[0041] In one embodiment, the rate matching signaling may be implemented using radio resource control (RRC) signaling transmitted over PDSCH. In another embodiment, it may be defined that a new signaling transmitted over PDCCH or e-PDCCH is used as the rate matching signaling. E-PDCCH may occupy part of resources of PDSCH.

[0042] According to the embodiments of the present invention, the rate matching signaling may not only notify the user equipment to start rate matching but also further comprise information on receiving time, which information indicates that the user equipment starts receiving data transmitted on resource block(s) according to a performing result of the rate matching from the receiving time.

[0043] Fig. 3 is a flowchart of a method 300 for interference suppression for user equipment in a heterogeneous network according to another embodiment of the present invention. The heterogeneous network may be the communication environment as shown in Fig. 1, for example. The heterogeneous network may comprise a Macro base station and a low power node, the user equipment is being served by the low power node, and the low power node transmits data to the user equipment on predefined resource block(s). The method 300 shown in Fig. 3 may be executed by a low power node (e.g., a Pico eNB), for example.

[0044] In step S301, a measurement report from the user equipment is received.

[0045] This step is similar to step S201. The measurement report at least comprises identification information of a neighboring cell causing interference on the user equipment. In one embodiment of the present invention, the measurement report may comprise: PCID, CGI, RSRP, RSRQ of a neighboring cell causing interference on the user equipment, etc.

[0046] In addition, it may be understood that the above examples are merely exemplary rather than limiting, and the measurement report may further comprise other appropriate parameters that are common or available to those skilled in the art.

[0047] In step S302, a neighboring cell causing interference on the user equipment is determined based on the measurement report.

[0048] In this embodiment, suppose the measurement report received in step S301 contains identification information of a Macrocell shown in Fig. 1, this indicates that the Macrocell causes interference on the user equipment. Then in step S301, the contained PCID or CGI may be read from the measurement report, for determining a specific cell causing interference on the user equipment.

[0049] In step S303, a cell reference signal of the neighboring cell is obtained. [0050] After determining a neighboring cell causing interference on the user equipment, cell reference signals, i.e., CRSs of the neighboring cell may be obtained. In the embodiments of the present invention, the obtaining of CRSs may comprise obtaining a time- frequency location corresponding to the CRSs and a sequence thereof. There may be various manners for obtaining CRSs; those skilled in the art may obtain CRSs in known, existing manners, without limitation to a specific manner.

[0051] In step S304, a resource element corresponding to the cell reference signals is determined as a Tx muted resource element.

[0052] According to the embodiments of the present invention, one resource block may comprise multiple resource elements, and a resource element may be regarded as a minimum unit in a resource block. After obtaining CRSs, it is possible to determine which resource element/elements in resource block(s) correspond to the CRSs. For example, one or more resource elements used for transmitting CRSs may be considered as Tx muted resource elements. In the subsequent procedure where the Picocell transmits data to its user equipment, data will not be transmitted on Tx muted resource element(s) in resource block(s) any more but will be transmitted on those other than the Tx muted resource element(s) in the resource block(s).

[0053] In other embodiments according to the present invention, improvement may be made to the procedure of determining the Tx muted resource elements as shown in steps S302-S304. For example, in one embodiment, after determining a neighboring cell causing interference on the user equipment based on the measurement report, the interference strength caused on the user equipment by the neighboring cell may be compared with a predefined threshold, wherein the interference strength may be obtained according to information (e.g., RSRP and/or RSRQ) in the measurement report from the user equipment, and the predefined threshold may be specified according to experiences or preset according to other criterion by those skilled in the art. Then, the neighboring cell whose interference strength exceeds the predefined threshold is determined as an interfering cell. This corresponds to refining neighboring cells which cause interference on the user equipment, and only those interfering cells whose interference is large to a certain extent are subjected to subsequent processing steps, i.e., obtaining cell reference signals of these interfering cells, and determining the resource elements which correspond to the cell reference signals as Tx muted resource elements. [0054] In step S305, a rate matching signaling is sent to the user equipment over PDSCH.

[0055] In this embodiment, rate matching signaling may be implemented using RRC signaling transmitted over PDSCH. In one embodiment of the present invention, The RRC signaling may be defined as a BOOLEAN type signal. When the RRC signaling is "TRUE," this indicates the user equipment performs rate matching for the upcoming resource blocks; when the RRC signaling is "FALSE," this indicates the user equipment does not need to perform rate matching for the upcoming resource blocks.

[0056] In another embodiment according to the present invention, it may be defined that a new signaling transmitted over PDCCH or e-PDCCH is used as the rate matching signaling. Since the control channel is updated fast, this manner is particularly suitable for the user equipment in high mobility. Relatively speaking, the RRC signaling may be suitable for the user equipment which is in relatively low mobility.

[0057] In addition, it may be understood that besides the RRC signaling in

PDSCH or the newly defined signaling in PDCCH or e-PDCCH, those skilled in the art may use any other appropriate signaling, which is well known in the art, to notify the user equipment to start rate matching.

[0058] In this embodiment, since the RRC signaling is used as the rate matching signaling, the user equipment may, for example, receive data transmitted on resource block(s) according to a performing result of the rate matching at the subframe (referred to as "the next subframe" for short) immediately after the subframe where the user equipment receives the rate matching signaling, in default.

[0059] In another embodiment according to the present invention, when the rate matching signaling is sent using PDCCH or e-PDCCH, the user equipment may, for example, perform the rate matching at the subframe (referred to as "the current subframe" for short) where it receives the rate matching signaling and receive data transmitted on resource block(s) according to a performing result of the rate matching.

[0060] According to the embodiments of the present invention, the rate matching signaling not only may notify the user equipment to start rate matching but also may further comprise information on receiving time, which information indicates the user equipment starts receiving data transmitted on resource block(s) according to a performing result of the rate matching from the receiving time. In one embodiment, besides the BOOLEAN type value, the RRC signaling may be defined to further comprise one or more bits indicative of time information, for representing information on the receiving time. For example, the RRC signaling may comprise one time information bit. When a value of the bit is "0," this indicates that the user equipment receives data transmitted on resource block(s) in the current subframe; and when a value of the bit is "1 ," this indicates that the user equipment receives data transmitted on resource block(s) in the next subframe, and so on and so forth.

[0061] It should be understood that in the embodiments according to the present invention, the information on receiving time may be implemented in any appropriate forms, without limitation to the above exemplary examples.

[0062] Fig. 4 is a flowchart of a method 400 for interference suppression for user equipment in a heterogeneous network according to one embodiment of the present invention. The heterogeneous network may be the communication environment as shown in Fig. 1 , for example. The heterogeneous network may comprise a Macro base station and a low power node, the user equipment is being served by the low power node, and the low power node transmits data to the user equipment on predefined resource block(s). The method 400 shown in Fig. 4 may be executed by user equipment served by a low power node (e.g., a Pico base station), for example.

[0063] In step S401 , a measurement report is sent to the low power node,

[0064] According to the embodiments of the present invention, the measurement report at least comprises: identification information of a neighboring cell causing interference on the user equipment.

[0065] In one embodiment of the present invention, the measurement report may comprise: a physical cell identifier (PCID), cell group identifier (CGI), reference signal receive power (RSRP), reference signal receive quality (RSRQ) of a neighboring cell causing interference on the user equipment.

[0066] In step S402, in response to a notification of performing rate matching from the low power node, rate matching is performed for a resource block containing a Tx muted resource element.

[0067] According to the embodiments of the present invention, step S402 may be implemented in various manners. In one embodiment, first a neighboring cell causing interference on the user equipment may be determined, then cell reference signals of the neighboring cell may be obtained, and finally resource elements corresponding to the cell reference signals may be determined as Tx muted resource elements in the resource block(s). In another embodiment, first a neighboring cell causing interference on the user equipment may be determined, then the interference strength caused on the user equipment by the neighboring cell may be compared with a predefined threshold, the neighboring cell whose interference strength exceeds the predefined threshold may be determined as an interfering cell, cell reference signals of the interfering cell may be obtained, and finally resource elements corresponding to the cell reference signals may be determined as the Tx muted resource elements in the resource block(s).

[0068] According to the embodiments of the present invention, the notification of performing rate matching may be rate matching signaling received in PDSCH, PDCCH or e-PDCCH. In one embodiment, the rate matching signaling may be implemented as RRC signaling transmitted over PDSCH. In another embodiment, the rate matching signaling may be a newly defined signaling in PDCCH or e-PDCCH.

[0069] According to the embodiments of the present invention, the rate matching signaling may further comprise information on receiving time, which information indicates the user equipment starts receiving data transmitted on resource block(s) according to a performing result of the rate matching from the receiving time.

[0070] In step S403, data transmitted on the resource block is received according to a performing result of the rate matching.

[0071] According to the embodiments of the present invention, in view of information on receiving time in the rate matching signaling, it is possible to start, from the receiving time, to receive data transmitted in resource block(s) according to the performing result of the rate matching.

[0072] According to the embodiments of the present invention, it is possible to identify Tx muted resource elements in the resource block(s) according to the performing result of the rate matching, and receive data transmitted on resource elements other than the Tx muted resource element(s) in the resource block(s).

[0073] Fig. 5 is a flowchart of a method 500 for interference suppression for user equipment in a heterogeneous network according to one embodiment of the present invention. The heterogeneous network may be the communication environment as shown in Fig. 1, for example. The heterogeneous network may comprise a Macro base station and a low power node, the user equipment is being served by the low power node, and the low power node transmits data to the user equipment on predefined resource block(s). The method 500 shown in Fig. 5 may be executed by user equipment served by a low power node (e.g., a Pico eNB), for example.

[0074] In step S501, a measurement report is sent to the low power node,

[0075] This step is similar to step S401. The measurement report at least comprises identification information of a neighboring cell causing interference on the user equipment. In one embodiment according to the present invention, the measurement report may comprise: PCID, CGI, RSRP, RSRQ of a neighboring cell causing interference on the user equipment, etc.

[0076] In the embodiments according to the present invention, the measurement report may be obtained and sent at the user equipment by various technical means that are well known in the art.

[0077] In step S502, a rate matching signaling in PDSCH is received.

[0078] In this embodiment, the rate matching signaling is implemented using RRC signaling transmitted over PDSCH. Thus, the RRC signaling in PDSCH is received in step S502. In one embodiment of the present invention, the RRC signaling may be defined as a BOOLEAN type signal. When the received RRC signaling is "TRUE," the user equipment may perform rate matching for the upcoming resource blocks; when the RRC signaling is "FALSE," the user equipment may not need to perform rate matching.

[0079] In another embodiment according to the present invention, the rate matching signaling may be defined as a new signaling transmitted over PDCCH or e-PDCCH. Since the control channel is updated fast, this manner is particularly suitable for the user equipment in relatively high mobility. Relatively speaking, the RRC signaling may be suitable for the user equipment in relatively low mobility.

[0080] In step S503, a neighboring cell causing interference on the user equipment is determined.

[0081] According to the embodiments of the present invention, the user equipment may periodically measure signal instructions and/or signal strength of neighboring cells, so that the user equipment may determine which neighboring cells cause interference on itself. Those skilled in the art may use various technical means that are well known in the art to implement such determination procedure.

[0082] In step S504, a cell reference signal of the neighboring cell is obtained.

[0083] After determining a neighboring cell causing interference on the user equipment, cell reference signals, i.e., CRSs of the neighboring cell may be obtained. In the embodiments of the present invention, the obtaining CRSs may comprise obtaining a time- frequency location corresponding to the CRSs and a sequence thereof. There may be various manners for obtaining CRSs; those skilled in the art may obtain CRSs in known, existing manners, without limitation to a specific manner.

[0084] In step S505, a resource element corresponding to the cell reference signals is determined as a Tx muted resource element.

[0085] According to the embodiments of the present invention, after obtaining CRSs, it is possible to determine which resource element/elements in the resource block correspond to the CRSs. For example, one or more resource elements used for transmitting CRSs may be used as resource elements corresponding to the CRSs. Then, the resource elements corresponding to the CRSs may be used as Tx muted resource elements.

[0086] In other embodiments according to the present invention, improvement may be made to the procedure of determining Tx muted resource elements as shown in steps S503-S505. For example, in one embodiment, after determining a neighboring cell causing interference on the user equipment, the interference strength caused on the user equipment by the neighboring cell may be compared with a predefined threshold, wherein the interference strength may be obtained by, for example, the user equipment measuring the strength and/or quality of CRSs from the neighboring cell, and the predefined threshold may be specified according to experiences or preset according to other criterion by those skilled in the art. Then, the neighboring cell whose interference strength exceeds the predefined threshold may be determined as an interfering cell. This corresponds to refining neighboring cells which cause interference on the user equipment, and only those interfering cells whose interference is large to a certain extent are subjected to subsequent processing steps, i.e., obtaining cell reference signals of those interfering cells, and determining resource elements which correspond to the cell reference signals as Tx muted resource elements.

[0087] In step S506, data transmitted on resource elements other than the Tx muted resource element in the resource block is received.

[0088] In this embodiment, since the RRC signaling is used as the rate matching signaling, the user equipment may, for example, receive data transmitted on the resource block(s) according to a performing result of the rate matching in the next subframe, in default.

[0089] In another embodiment according to the present invention, when the rate matching signaling is sent using PDCCH or e-PDCCH, the user equipment may, for example, receive data transmitted on resource block(s) according to a performing result of the rate matching in the current subframe, in default.

[0090] According to the embodiments of the present invention, the rate matching signaling not only may notify the user equipment to start rate matching but also may further comprise information on receiving time, which information indicates the user equipment starts to receive data transmitted on resource block(s) from the receiving time according to a performing result of the rate matching. In view of information on receiving time in the rate matching signaling, data transmitted on resource block(s) may be received from the receiving time according to a performing result of the rate matching. For example, when the RRC signaling is used as the rate matching signaling, one time information bit may be further comprised. When the user equipment detects a value of the bit is "0," data transmitted on resource block(s) is received in the same subframe where the rate matching signaling is received; and when the user equipment detects the value of the bit is "1 ," data transmitted on resource block(s) is received in the subframe immediately after a subframe where the rate matching signaling is received.

[0091] Fig. 6 is a block diagram of an apparatus 600 for interference suppression for user equipment in a heterogeneous network according to one embodiment of the present invention. The heterogeneous network may be the communication environment as shown in Fig. 1, for example. The heterogeneous network may comprise a Macro base station and a low power node, the user equipment is being served by the low power node, and the low power node transmits data to the user equipment on predefined resource block(s). The apparatus 600 shown in Fig. 6 may be implemented in a low power node, such as a Pico base station and the like, in a heterogeneous network, or may be implemented in any other appropriate apparatus that is available to those skilled in the art. The apparatus 600 may execute the method 200 shown in Fig. 2 and the method 300 shown in Fig. 3.

[0092] According to the embodiments of the present invention, the apparatus

600 may comprise: measurement report receiving component 610 configured to receive a measurement report from the user equipment; determining component 620 configured to determine Tx muted resource elements among the resource blocks based on the measurement report; and notifying component 630 configured to notify the user equipment to perform rate matching, so that the user equipment receives data transmitted on the resource blocks according to a performing result of the rate matching.

[0093] According to the embodiments of the present invention, the measurement report may at least comprise: identification information of a neighboring cell causing interference on the user equipment.

[0094] According to the embodiments of the present invention, the determining component 620 may comprise: a unit configured to determine a neighboring cell causing interference on the user equipment based on the measurement report; a unit configured to obtain a cell reference signal of the neighboring cell; and a unit configured to determine a resource element corresponding to the cell reference signal as the Tx muted resource element.

[0095] According to the embodiments of the present invention, the determining component 620 may comprise: a unit configured to determine a neighboring cell causing interference on the user equipment based on the measurement report; a unit configured to compare strength of interference on the user equipment caused by the neighboring cell with a predefined threshold; a unit configured to determine a neighboring cell whose strength of interference exceeds the predefined threshold as an interfering cell; a unit configured to obtain a cell reference signal of the interfering cell; and a unit configured to determine a resource element corresponding to the cell reference signal as the Tx muted resource element.

[0096] According to the embodiments of the present invention, the notifying component 630 may comprise: a unit configured to send rate matching signaling to the user equipment in the Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH) or enhanced Physical Downlink Control Channel (e-PDCCH).

[0097] According to the embodiments of the present invention, the rate matching signaling may comprise information on receiving time, for notifying the user equipment to start from the receiving time to receive data transmitted on the resource block according to the performing result of the rate matching.

[0098] Fig. 7 is a block diagram of an apparatus 700 for interference suppression for user equipment in a heterogeneous network according to one embodiment of the present invention. The heterogeneous network may be the communication environment as shown in Fig. 1, for example. The heterogeneous network may comprise a Macro base station and a low power node, the user equipment is being served by the low power node, and the low power node transmits data to the user equipment on a predefined resource block. The apparatus 700 shown in Fig. 7 may be implemented in user equipment served by a low power node, such as a Pico base station and the like, in a heterogeneous network, or may be implemented in any other appropriate apparatus that is available to those skilled in the art. The apparatus 700 may execute the method 400 shown in Fig. 4 and the method 500 shown in Fig. 5.

[0099] According to the embodiments of the present invention, the apparatus 700 may comprise: sending component 710 configured to send a measurement report to the low power node; rate matching performing component 720 configured to, in response to a notification of performing rate matching from the low power node, perform rate matching for the resource block containing Tx muted resource elements; and data receiving component 730 configured to receive data transmitted on the resource block according to a performing result of the rate matching.

[00100] According to the embodiments of the present invention, the measurement report may at least comprise: identification information of a neighboring cell causing interference on the user equipment.

[00101] According to the embodiments of the present invention, the rate matching performing component 720 may comprise: a unit configured to determine a neighboring cell causing interference on the user equipment; a unit configured to obtain cell reference signals of the neighboring cell; and a unit configured to determine resource elements corresponding to the cell reference signals as the Tx muted resource element in the resource block.

[00102] According to the embodiments of the present invention, the rate matching performing component 720 may comprise: a unit configured to determine a neighboring cell causing interference on the user equipment; a unit configured to compare strength of interference on the user equipment caused by the neighboring cell with a predefined threshold; a unit configured to determine a neighboring cell whose strength of interference exceeds the predefined threshold as an interfering cell; a unit configured to obtain a cell reference signal of the interfering cell; and a unit configured to determine a resource element corresponding to the cell reference signal as the Tx muted resource element in the resource block.

[00103] According to the embodiments of the present invention, the notification of performing rate matching may be rate matching signaling received in the Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH) or enhanced Physical Downlink Control Channel (e-PDCCH).

[00104] According to the embodiments of the present invention, the rate matching signaling may comprise information on receiving time, wherein the data receiving component 730 may comprise: a unit configured to start, from the receiving time, to receive data transmitted in the resource block according to the performing result of the rate matching.

[00105] According to the embodiments of the present invention, the data receiving component 730 may comprise: a unit configured to identify a Tx muted resource element in the resource block according to the performing result of the rate matching; and a unit configured to receive data transmitted on a resource element other than the Tx muted resource element in the resource block.

[00106] According to the embodiments of the present invention, the low power node is a Pico base station, e.g., Pico BS, Pico eNodeB/eNB.

[00107] The methods and apparatuses for interference suppression for user equipment in a heterogeneous network are simply implemented, use less signaling and can realize Tx muting and user equipment rate matching in a simple, high-efficiency and convenient manner, thereby completing interference suppression for user equipment served by a low power node.

[00108] The methods as disclosed in the present invention can be implemented in software, hardware or combination of software and hardware. The hardware portion can be implemented by using dedicated logic; the software portion can be stored in a memory and executed by an appropriate instruction executing system such as a microprocessor, a personal computer (PC) or a mainframe computer. In a preferred embodiment, the present invention is implemented as software, including, without limitation to, firmware, resident software, micro-code, etc.

[00109] Moreover, the embodiments of the present invention may be implemented as a computer program product accessible by computer useable or readable media that provide program code for use by or in connection with a computer or any instruction executing system. For the purpose of description, a computer-usable or computer-readable medium may be any tangible means that can contain, store, communicate, propagate, or transport the program for use by or in connection with an instruction execution system, apparatus, or device.

[00110] The medium may be an electric, magnetic, optical, electromagnetic, infrared, or semiconductor system (apparatus or device), or propagation medium. Examples of the computer-readable medium would include the following: a semiconductor or solid storage device, a magnetic tape, a portable computer diskette, a random access memory (RAM), a read-only memory (ROM), a hard disk, and an optical disk. Examples of the current optical disk include a compact disk read-only memory (CD-ROM), compact disk-read/write (CR-ROM), and DVD.

[00111] A system adapted for storing and/or executing program code according to the embodiments of the present invention would include at least one processor that is coupled to a memory element directly or via a system bus. The memory element may include a local memory usable during actually executing the program code, a mass memory, and a cache that provides temporary storage for at least one portion of program code so as to decrease the number of times for retrieving code from the mass memory during execution.

[00112] An Input/Output or I/O device (including, without limitation to, a keyboard, a display, a pointing device, etc.) may be coupled to the system directly or via an intermediate I/O controller.

[00113] A network adapter may also be coupled to the system such that the data processing system can be coupled to other data processing systems, remote printers or storage devices via an intermediate private or public network. A modem, a cable modem, and an Ethernet card are merely examples of a currently available network adapter.

[00114] It should be noted that some more specific technical details that are publicly known to those skilled in the art and that might be essential to the implementation of the present invention are omitted in the above description in order to make the present invention more easily understood.

[00115] The specification of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art.

[00116] Therefore, the embodiments were chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand that all modifications and alterations made without departing from the spirit of the present invention fall into the protection scope of the present invention as defined in the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A method for interference suppression for a user equipment in a heterogeneous network, wherein the heterogeneous network comprises a Macro base station and a low power node, the user equipment is served by the low power node, and the low power node transmits data to the user equipment on a predefined resource block, the method comprising:

receiving a measurement report from the user equipment;

determining a transmission (Tx) muted resource element in the resource block based on the measurement report; and

notifying the user equipment to perform rate matching, so that the user equipment receives data transmitted on the resource block according to a performing result of the rate matching.

2. The method according to claim 1, wherein the measurement report at least comprises: identification information of a neighboring cell causing interference on the user equipment.

3. The method according to claim 1, wherein determining a Tx muted resource element in the resource block based on the measurement report comprises:

determining a neighboring cell causing interference on the user equipment based on the measurement report;

obtaining a cell reference signal of the neighboring cell; and

determining a resource element corresponding to the cell reference signal as the Tx muted resource element

4. The method according to claim 1, wherein determining a Tx muted resource element in the resource block based on the measurement report comprises:

comparing strength of interference on the user equipment caused by the neighboring cell with a predefined threshold;

determining a neighboring cell whose strength of interference exceeds the predefined threshold as an interfering cell;

obtaining a cell reference signal of the interfering cell; and

determining a resource element corresponding to the cell reference signal as the Tx muted resource element.

5. The method according to claim 1, wherein the notifying the user equipment to perform rate matching comprises:

sending a rate matching signaling to the user equipment in the Physical Downlink

Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH) or enhanced Physical Downlink Control Channel (e-PDCCH).

6. The method according to claim 5, wherein the rate matching signaling comprises information on receiving time, for notifying the user equipment to start from the receiving time to receive data transmitted on the resource block according to the performing result of the rate matching .

7. A method for interference suppression for a user equipment in a heterogeneous network, wherein the heterogeneous network comprises a Macro base station and a low power node, the user equipment is served by the low power node, and the low power node transmits data to the user equipment on a predefined resource block, the method comprising:

sending a measurement report to the low power node;

in response to a notification of performing rate matching from the low power node, performing rate matching for the resource block containing a transmission (Tx) muted resource element; and

receiving data transmitted on the resource block according to a performing result of the rate matching.

8. The method according to claim 7, wherein the measurement report at least comprises: identification information of a neighboring cell causing interference on the user equipment.

9. The method according to claim 7, wherein performing rate matching for the resource block containing a Tx muted resource element comprises:

determining a neighboring cell causing interference on the user equipment;

obtaining cell reference signals of the neighboring cell; and

determining resource elements corresponding to the cell reference signals as the Tx muted resource element in the resource block.

10. The method according to claim 7, wherein performing rate matching for the resource block containing a Tx muted resource element comprises:

determining a neighboring cell causing interference on the user equipment;

obtaining a cell reference signal of the interfering cell; and

determining a resource element corresponding to the cell reference signal as the Tx muted resource element in the resource block.

11. The method according to claim 7, wherein the notification of performing rate matching is a rate matching signaling received in the Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH) or enhanced Physical Downlink Control Channel (e-PDCCH).

12. The method according to claim 11, wherein the rate matching signaling comprises information on receiving time, wherein receiving data transmitted on the resource block according to a performing result of the rate matching comprises:

starting, from the receiving time, to receive data transmitted on the resource block according to the performing result of the rate matching .

13. The method according to claim 7, wherein receiving data transmitted on the resource block according to a performing result of the rate matching comprises:

identifying a Tx muted resource element in the resource block according to the performing result of the rate matching; and

receiving data transmitted on a resource element other than the Tx muted resource element in the resource block.

14. An apparatus for interference suppression for a user equipment in a heterogeneous network, wherein the heterogeneous network comprises a Macro base station and a low power node, the user equipment is served by the low power node, and the low power node transmits data to the user equipment on a predefined resource block, the apparatus comprising:

measurement report receiving component configured to receive a measurement report from the user equipment;

determining component configured to determine a transmission (Tx) resource element in the resource block based on the measurement report; and

notifying component configured to notify the user equipment to perform rate matching, so that the user equipment receives data transmitted on the resource block according to a performing result of the rate matching.

15. The apparatus according to claim 14, wherein the measurement report at least comprises: identification information of a neighboring cell causing interference on the user equipment.

16. The apparatus according to claim 14, wherein the determining component comprises:

a unit configured to determine a neighboring cell causing interference on the user equipment based on the measurement report;

a unit configured to obtain a cell reference signal of the neighboring cell; and a unit configured to determine a resource element corresponding to the cell reference signal as the Tx muted resource element.

17. The apparatus according to claim 14, wherein the determining component comprises:

a unit configured to compare strength of interference on the user equipment caused by the neighboring cell with a predefined threshold;

a unit configured to determine a neighboring cell whose strength of interference exceeds the predefined threshold as an interfering cell;

a unit configured to obtain a cell reference signal of the interfering cell; and a unit configured to determine a resource element corresponding to the cell reference signal as the Tx muted resource element.

18. The apparatus according to claim 14, wherein the notifying component comprises:

a unit configured to send a rate matching signaling to the user equipment in the Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH) or enhanced Physical Downlink Control Channel (e-PDCCH).

19. The apparatus according to claim 18, wherein the rate matching signaling comprises information on receiving time, for notifying the user equipment to start from the receiving time to receive data transmitted on the resource block according to the performing result of the rate matching.

20. An apparatus for interference suppression for a user equipment in a heterogeneous network, wherein the heterogeneous network comprises a Macro base station and a low power node, the user equipment is served by the low power node, and the low power node transmits data to the user equipment on a predefined resource block, the apparatus comprising:

sending component configured to send a measurement report to the low power node;

rate matching performing component configured to, in response to a notification of performing rate matching from the low power node, perform rate matching for the resource block containing a transmission (Tx) muted resource element; and data receiving component configured to receive data transmitted on the resource block according to a performing result of the rate matching.

21. The apparatus according to claim 20, wherein the measurement report at least comprises: identification information of a neighboring cell causing interference on the user equipment.

22. The apparatus according to claim 20, wherein the rate matching performing component comprises:

a unit configured to determine a neighboring cell causing interference on the user equipment;

a unit configured to obtain cell reference signals of the neighboring cell; and a unit configured to determine resource elements corresponding to the cell reference signals as the Tx muted resource element in the resource block.

23. The apparatus according to claim 20, wherein the rate matching performing component comprises:

a unit configured to obtain a cell reference signal of the interfering cell; and a unit configured to determine a resource element corresponding to the cell reference signal as the Tx muted resource element in the resource block.

24. The apparatus according to claim 24, wherein the notification of performing rate matching is a rate matching signaling received in the Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH) or enhanced Physical Downlink Control Channel (e-PDCCH).

25. The apparatus according to claim 24, wherein the rate matching signaling comprises information on receiving time, wherein the data receiving component comprises:

a unit configured to start, from the receiving time, to receive data transmitted in the resource block according to the performing result of the rate matching.

26. The apparatus according to claim 20, wherein the data receiving component comprises:

a unit configured to identify a Tx muted resource element in the resource block according to the performing result of the rate matching; and

a unit configured to receive data transmitted on a resource element other than the Tx muted resource element in the resource block.

27. The apparatus according to claim 20, wherein the low power node is a Pico base station.