WO2015168907A1

WO2015168907A1 - Method and apparatus for assisting ue to reduce interference

Info

Publication number: WO2015168907A1
Application number: PCT/CN2014/077056
Authority: WO
Inventors: Teck Hu; Matthew Baker; Zheng Liu; Shin Horng Wong
Original assignee: Alcatel Lucent; Alcatel-Lucent Shanghai Bell Co., Ltd
Priority date: 2014-05-08
Filing date: 2014-05-08
Publication date: 2015-11-12
Also published as: CN106465350A; CN106465350B; TW201611643A

Abstract

The present invention aims to assist UE to reduce the interference from the neighboring base station by providing UE with subset restriction(SR)related information which includes one or more levels of multiple-level signaling. According to the present invention, an apparatus, in a base station in a wireless network, for assisting UE served by another base station to reduce interference, is provided, the apparatus comprises: means for receiving the request for subset restriction from the serving base station; means for, in response to the request, providing the subset restriction related information to said serving base station, wherein the SR related information may comprise one or more levels of multiple-level signaling, the first level of which indicating whether to activate SR and the next levels of which indicating the specifics of SR if SR is to be activated. With the present invention, the following advantages are achieved: -1)The subset restriction related information provided by the interfering base station assists UE to reduce the erroneous detection and improve its throughout performance; 2)The hierarchy of multiple-level signaling provides more flexibility for base stations to indicate various combinations of subset restriction. This is to allow base stations to decide to start or stop the subset restriction; 3)The hierarchy of multiple-level signaling provides a flexibility to accommodate future expansion.

Description

METHOD AND APPARATUS FOR ASSISTING UE TO REDUCE INTERFERENCE

Field Of The Invention

[0001] This invention relates to the field of wireless network, especially to a technique on assisting UE to reduce interference in a wireless network.

DESCRIPTION OF THE RELATED ART

[0002] In various wireless networks ( e.g. wireless network based on 3GPP ) , User Equipment(UE) in one cell served by a base station, which is located close to the periphery covered by a neighboring base station, will be subjected to interference from the neighboring base station. The interference will cause erroneous detections in UE and affect the throughout performance thereof.

[0003] Network Assisted Interference Cancellation & Suppression (NAICS) is currently proposed in Release- 12 Work Item(WI) of 3 GPP, which is to provide information related to interferer so that the UE can use this information to cancel or suppress that interference thereby reduce erroneous detections and improving the throughput performance. However, no specific of NAICS is disclosed in Release-12 WI.

SUMMARY OF THE INVENTION

[0004] The present invention aims to assist UE to reduce the interference from the neighboring base station by providing UE with subset restriction (SR) related information which includes one or more levels of multiple-level signaling.

[0005] According to an embodiment, an apparatus, in a base station in a wireless network, for assisting UE served by another base station to reduce interference, is provided, the apparatus comprises:

[0006] means for receiving the request for subset restriction(SR) from the serving base station;

[0007] means for, in response to the request, providing the subset restriction related information to said serving base station, wherein the SR related information may comprise one or more levels of multiple-level signaling, the first level of which indicating whether to activate SR and the next levels of which indicating the specifics of SR if SR is to be activated.

[0008] According to a second embodiment, an apparatus, in a base station in a wireless network, for assisting UE served by the base station itself to reduce interference, is provided, the apparatus comprises:

[0009] means for sending a request for subset restriction(SR) to a interfering base station;

[0010] means for receiving the subset restriction related information sent by said interfering base station in response to the request, wherein the subset restriction related information may comprise one or more levels of multiple-level signaling, the first level of which indicating whether to activate SR and the next levels of which indicating the specifics of SR if SR is to be activated;

[0011] means for forwarding the received subset restriction related information to an UE which needs NAICS.

[0012] According to a third embodiment, a method, in a base station in a wireless network, for assisting UE served y the base station itself to reduce interference, is provided, the method comprises:

[0013] - receiving the request for subset restriction(SR) from the serving base station;

[0014] - providing, in response to the request, the subset restriction related information to said serving base station, wherein the subset restriction related related information may comprise one or more levels of multiple-level signaling, the first level of which indicating whether to activate SR and the next levels of which indicating the specifics of SR if SR is to be activated.

[0015] According to a fourth embodiment, a method, in a base station in a wireless network, for assisting UE served by the base station itself to reduce interference, is provide, the method comprises:

[0016] - sending a request for subset restriction(SR) to a interfering base station;

[0017] - receiving the subset restriction related information sent by said interfering base station in response to the request, wherein the subset restriction related information may comprise one or more levels of multiple-level signaling, the first level of which indicating whether to activate SR and the next levels of which indicating the specifics of SR if SR is to be activated;

[0018] - forwarding the received subset restriction related information to an UE which needs NAICS.

[0019] With the present invention, the following advantages are achieved:

[0020] - The subset restriction related information provided by the interfering base station assists UE to reduce the erroneous detection and improve its throughout performance;

[0021] - The hierarchy of multiple-level signaling provides more flexibility for base stations to indicate various combinations of subset restriction. This is to allow base stations to decide to start or stop the subset restriction;

[0022] - The hierarchy of multiple-level signaling provides a flexibility to accommodate future expansion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other features, purposes and advantages of the invention will become more explicit by means of reading the detailed statement of the non-restrictive embodiments made with reference to the accompanying drawings.

[0024] Fig. 1 shows an example scenario of a wireless network;

[0025] Fig. 2 shows the flowchart of method for assisting User Equipment to reduce interference according to one embodiment of the present invention;

[0026] Fig. 3 shows the flowchart of method for assisting User Equipment to reduce interference according to another embodiment of the present invention;

[0027] Fig. 4 shows the schematic diagram of system for assisting User Equipment to reduce interference according to one embodiment of the present invention;

[0028] Fig. 5 shows schematic diagram of system for assisting User Equipment to reduce interference according to one embodiment of the present invention.

[0029] The same or similar reference signs in the drawings represent the same or similar component parts.

DETAILED DESCRIPTION OF THE INVENTION

[0030] Further description of this invention would be given as follow by reference of the drawings.

Definition of Technical Terms:

[0031] For Clarity, we make definition of some terms in the context at first, as follows: [0032] - "Wireless Network" means the telecommunication network for voice and/or date transmission via wireless signal, which comprises a plurality of base station each of which servers one or more cells, in which there are one or more User Equipments. The Wireless Network comprises, but not limited to, the wireless network based on GSM, CDMA, 3GPP(3rd Generation Partnership Project) protocols.

[0033] - "Base Station" means a radio station having bidirectional transceiver which can have uplink and downlink communication, via radio signal, with UEs in the cell it serves, and can also communicate with other base station directly or indirectly. The Wireless Network comprises, but not limited to, base station in the wireless network based on GSM protocol, Node B in the wireless network based on CDMA protocol, and e-Node B in the wireless network based on 3GPP protocol.

[0034] - "User Equipment" means a communication device used by the user which can have uplink and downlink communication with the base station in the wireless network. User Equipment comprises, but not limited to, mobile phone, laptop or tablet computer having telecommunication module for the wireless network.

[0035] Fig. 1 illustrates an example scenario of a wireless network, which comprises a plurality of base stations, each of which serves a cell. And, in each cell, there are a plurality of User Equipments. For clarity, only two base stations BS1 , BS2 are shown. And, for more clarity, only one User Equipment UE3 is the cell served by the base station BS2, which is called "the serving base station", is shown. UE3 is located close to the periphery covered by BS 1 and subjected to interference from BS1 , which is called "the interfering bass station", when communicates with BS2 in downlink. Wherein, the wireless network may be wireless network based on 3 GPP. Preferably, it is a LTE network, and the base stations are e-Node B of LTE network.

[0036] Fig. 2 illustrates the flowchart of method for assisting User Equipment to reduce interference according to one embodiment of the present invention. The detailed description thereof will be made by reference Fig. 2 in connection with Fig. 1 as follows:

[0037] As shown by Fig. 1 , UE3 in the cell of BS2 is located close to the periphery of cell of BSl , hence subjected to the interference from BSl during the downlink and uplink communication with BS2.

[0038] For assisting UE3 to cancel & suppress the downlink interference from BSl , at the step S201 , BS2 sends to BSl a request for requesting BS l to start a Subset Restriction (SR) operation, that is, the base station restricts some parameter related to downlink communication to a subset so as to avoid interfering other neighboring base stations.

[0039] The request may only include an indication of the existence of UE which needs Network Assisting Interference Cancellation & Suppression (NAICS), or include a definite information for requesting BS l to activate a SR operation. It could be understood by the person skilled in the art that the request may include other types of information for requesting BS l to activate a SR operation.

[0040] After receiving the request for SR from BS2, at step S202, BS l sends to BS2 a SR related information as a response. It could be understood by the person skilled in the art that the SR related information may be contained in the specific fields of the message specified by the specification of existing Interfaces between two base stations, such as X2 interface, or may be carried by a new signaling over the existing or new interfaces between two base stations. It shall be understood that other ways for carrying the SR related information, if applicable to the present invention, shall fall into the protection scope thereof and be incorporated herein by reference.

[0041] The SR related information may comprise multiple-level signaling, the first level of which indicate whether to activate SR; the next levels of which indicate the specifics of SR if SR is to be activated. For example, in the case of two-level signaling, the first level of signaling is a N-bit SR binary sequence which is specific to the base station. Each bit of the sequence corresponds a difference parameter which could be executed a SR operation. When a bit is "1", it indicates that a SR operation is to be active to its corresponding parameter; otherwise, when the bit is "0", it means that no SR operation be activated to its corresponding parameter. And, the second level of signaling comprise one or more Information Elements (IEs) corresponding to part of or all of "1" bits in the sequence. Each IE corresponds to a different "1" bit of the N-bit SR binary sequence and defines the specific information of the SR operation to the parameter which the "1" bit corresponds to.

[0042] In an example, the SR related information includes a N-bit SR binary sequence which is specific to the base station. Each bit of the sequence corresponds a difference parameter which could be executed a SR operation. When a bit is "1", it indicates that a SR operation is to be active to its corresponding parameter; otherwise, when the bit is "0", it means that no SR operation be activated to its corresponding parameter.

[0043] In another example, besides the a N-bit SR binary sequence, the SR related information further includes some Information Elements (IEs) corresponding to part of or all of "1" bits in the sequence. Each IE corresponds to a different "1" bit of the N-bit SR binary sequence and defines the specific information of the SR operation to the parameter which the "1" bit corresponds to. For example: [0044] - for Transmission Mode (TM) bit of "1", its corresponding IE define the range or the specific subset of the transmission modes being restricted.

[0045] - for Physical Resource Block (PRB) bit of "1", its corresponding IE defines the number or specific subset of PRBs being restricted.

[0046] - for Code Book(CB) bit of "1", its corresponding IE defines the number or the specific subset of codes in the code book being restricted.

[0047] In an alternative example, the N-bit SR sequence is static or semi-static, that is, it needs not to be updated frequently. Specifically, an interfering base station may inform its N-bit SR sequence to other base stations via a global broadcast or just send its N-bit SR sequence to other base stations once in response to the request thereof. Once received the N-bit SR sequence from the interfering base station, the other base stations maintain it in the storage device which will not be updated until receiving a new N-bit SR sequence from the same interfering base station next time. In this case, since BS2 keeps the N-bit SR sequence sent by BS 1 before, BS2 needs only to send to BS1 the IEs corresponding to part of or all of "1" bits of the N-bit SR sequence, each of which defines the specifics of subset restriction of the parameter it corresponds to. In this way, it is avoided to frequently send the N-bit SR sequence each time, hence greatly reduce signaling overheads in the transmission of SR related information.

[0048] After receiving the SR related information from BS1 , BS2 forwards this SR related information to UE3. UE3 will use this SR related information in the process of detections and gains the beneficial of detection performance and complexity.

[0049] Fig. 3 illustrates the flowchart of method for assisting User Equipment to reduce interference according to another embodiment of the present invention. We will make detailed description thereof by reference Fig. 3 in connection with Fig. 1 as follows:

[0050] As shown by Fig. 1 , UE3 in the cell of BS2 is located close to the periphery of cell of BSl , hence subjected to the interference from BSl during the downlink and uplink communication with BS2.

[0051] For assisting UE3 to cancel & suppress the downlink interference from BSl , at the step S301 , BS2 sends to BSl a request for requesting BSl to activate a Subset Restriction (SR) operation, that is, the base station restricts some parameter related to downlink communication to a subset so as to avoid interfering other neighboring base stations.

[0052] The request may only include an indication of the existence of UE which needs Network Assisting Interference Cancellation & Suppression (NAICS), or include a definite information for requesting BS l to activate a SR operation. It could be understood by the person skilled in the art that the request may include other types of information for requesting BS l to activate a SR operation, which shall fall into the protection scope thereof and be incorporated herein by reference.

[0053] After receiving the request for SR from BS2, at step S302, BSl determines, based on the request, whether to activate SR. For example, once receiving the request, BSl estimates the effect to its system performance caused by a SR to be activated. Its system performance comprises, but is not limited to, any combination of the performance or flexibility of its scheduler, the number of UEs it serves or its throughout capacity, and the like. If the effect does not go beyond the predefined condition, it then determines to activate a SR; otherwise, it determines not to activate a SR. It could be understood by the person skilled in the art that other ways for determining whether to activate a SR operation, if applicable to the present invention, shall fall into the protection scope thereof and be incorporated herein by reference.

[0054] In this way, it can provide more flexibility for the interfering base station, i.e. BS 1 , to determine whether start SR or not, hence gains a balance between the stability of system performance and provide UE with network assisting interference cancellation & suppression.

[0055] At step S303, if determines to activate SR, BS1 sends to BS2 a SR related information as a response. It could be understood by the person skilled in the art that the SR related information may be contained in the specific fields of the message specified by the specification of existing Interfaces between two base stations, such as X2 interface, or may be carried by a new signaling over the existing or new interfaces between two base stations. It shall be understood that other ways for carrying the SR related information, if applicable to the present invention, shall fall into the protection scope thereof and be incorporated herein by reference.

[0056] The SR related information may comprise multiple-level signaling, the first level of which indicate whether to activate SR; the next levels of which indicate the specifics of SR if SR is to be activated. For example, in the case of two-level signaling, the first level of signaling is a N-bit SR binary sequence which is specific to the base station. Each bit of the sequence corresponds a difference parameter which could be executed a SR operation. When a bit is "1", it indicates that a SR operation is to be active to its corresponding parameter; otherwise, when the bit is "0", it means that no SR operation be activated to its corresponding parameter. And, the second level of signaling comprise one or more Information Elements (IEs) corresponding to part of or all of "1" bits in the sequence. Each IE corresponds to a different "1" bit of the N-bit SR binary sequence and defines the specific information of the SR operation to the parameter which the "1" bit corresponds to. [0057] In an example, the SR related information only includes a N-bit SR binary sequence which is specific to the base station. Each bit of the sequence corresponds a difference parameter which could be executed a SR operation. When a bit is "1", it indicates that a SR operation is to be active to its corresponding parameter; otherwise, when the bit is "0", it means that no SR operation be activated to its corresponding parameter.

[0058] In another embodiment, besides the a N-bit SR binary sequence, the SR related information further includes some Information Elements (IEs) corresponding to part of or all of "1" bits in the sequence. Each IE corresponds to a different "1" bit of the N-bit SR binary sequence and defines the specific information of the SR operation to the parameter which the "1" bit corresponds to. For example:

[0059] - for Transmission Mode (TM) bit of "1", its corresponding IE define the range or the specific subset of the transmission modes being restricted.

[0060] - for Physical Resource Block (PRB) bit of "1", its corresponding IE defines the number or specific subset of PRBs being restricted.

[0061] - for Code Book(CB) bit of "1", its corresponding IE defines the number or the specific subset of codes in the code book being restricted.

[0062] In an example, the N-bit SR sequence is static or semi-static, that is, it needs not to be updated frequently. Specifically, an interfering base station may inform its N-bit SR sequence to other base stations via a global broadcast or just send its N-bit SR sequence to other base stations once in response to the request thereof. Once received the N-bit SR sequence from the interfering base station, the other base stations maintain it in the storage device which will not be updated until receiving a new N-bit SR sequence from the same interfering base station next time. In this case, since BS2 keeps the N-bit SR sequence sent by BS1 before, BS2 needs only to send to BS 1 the IEs corresponding to part of or all of "1" bits of the N-bit SR sequence, each of which defines the specifics of subset restriction of the parameter it corresponds to. In this way, it is avoided to frequently send the N-bit SR sequence each time, hence greatly reduce signaling overheads in the transmission of SR related information.

[0063] At step S305(not shown), if determines not to activate SR, BS2 may send a response, such as a Non-acknowledgement (NAK) or a N-Bit SR sequence of all "0" bits, to BS2 to indicate that no SR is activated. Alternatively, BS2 may also simply not send the response to BS2 to indicate to indicate that no SR is activated. It shall be understood that other ways for indicating not to activate SR, if applicable to the present invention, shall be incorporated herein by reference and fall into the protection scope thereof.

[0064] At step S304, once receiving the SR related information from BS 1 , BS2 forwards this SR related information to UE3. UE3 will use this SR related information in the process of detections and gains the beneficial of detection performance and complexity.

[0065] Fig. 4 illustrates the schematic diagram of system for assisting User Equipment to reduce interference according to one embodiment of the present invention. The detailed description thereof will be made by reference Fig. 4 in connection with Fig. 1 as follows:

[0066] As shown by Fig. 1 , UE3 in the cell of BS2 is located close to the periphery of cell of BS1 , hence subjected to the interference from BS1 during the downlink and uplink communication with BS2.

[0067] For assisting UE3 to cancel & suppress the downlink interference from BS1 , in BS2, means 21 , called "sending device", sends to BS 1 a request for requesting BS 1 to start a Subset Restriction (SR) operation, that is, the base station restricts some parameter related to downlink communication to a subset so as to avoid interfering other neighboring base stations.

[0068] The request may only include an indication of the existence of UE which needs Network Assisting Interference Cancellation & Suppression (NAICS), or include a definite information for requesting BS 1 to activate a SR operation. It could be understood by the person skilled in the art that the request may include other types of information for requesting BS 1 to activate a SR operation.

[0069] After receiving the request for SR from BS2, in BS1 , means 11 , called " providing device", sends to BS2 a SR related information as a response. It could be understood by the person skilled in the art that the SR related information may be contained in the specific fields of the message specified by the specification of existing Interfaces between two base stations, such as X2 interface, or may be carried by a new signaling over the existing or new interfaces between two base stations. It shall be understood that other ways for carrying the SR related information, if applicable to the present invention, shall fall into the protection scope thereof and be incorporated herein by reference.

[0070] The SR related information may comprise multiple-level signaling, the first level of which indicate whether to activate SR; the next levels of which indicate the specifics of SR if SR is to be activated. For example, in the case of two-level signaling, the first level of signaling is a N-bit SR binary sequence which is specific to the base station. Each bit of the sequence corresponds a difference parameter which could be executed a SR operation. When a bit is "1", it indicates that a SR operation is to be active to its corresponding parameter; otherwise, when the bit is "0", it means that no SR operation be activated to its corresponding parameter. And, the second level of signaling comprise one or more Information Elements (IEs) corresponding to part of or all of "1" bits in the sequence. Each IE corresponds to a different "1" bit of the N-bit SR binary sequence and defines the specific information of the SR operation to the parameter which the "1" bit corresponds to.

[0071] In an example, the SR related information includes a N-bit SR binary sequence which is specific to the base station. Each bit of the sequence corresponds a difference parameter which could be executed a SR operation. When a bit is "1", it indicates that a SR operation is to be active to its corresponding parameter; otherwise, when the bit is "0", it means that no SR operation be activated to its corresponding parameter.

[0072] In another example, besides the a N-bit SR binary sequence, the SR related information further includes some Information Elements (IEs) corresponding to part of or all of "1" bits in the sequence. Each IE corresponds to a different "1" bit of the N-bit SR binary sequence and defines the specific information of the SR operation to the parameter which the "1" bit corresponds to. For example:

[0073] - for Transmission Mode (TM) bit of "1", its corresponding IE define the range or the specific subset of the transmission modes being restricted.

[0074] - for Physical Resource Block (PRB) bit of "1", its corresponding IE defines the number or specific subset of PRBs being restricted.

[0075] - for Code Book(CB) bit of "1", its corresponding IE defines the number or the specific subset of codes in the code book being restricted.

[0076] In an alternative example, the N-bit SR sequence is static or semi-static, that is, it needs not to be updated frequently. Specifically, an interfering base station may inform its N-bit SR sequence to other base stations via a global broadcast or just send its N-bit SR sequence to other base stations once in response to the request thereof. Once received the N-bit SR sequence from the interfering base station, the other base stations maintain it in the storage device which will not be updated until receiving a new N-bit SR sequence from the same interfering base station next time. In this case, since BS2 keeps the N-bit SR sequence sent by BS l before, BS2 needs only to send to BSl the IEs corresponding to part of or all of "1" bits of the N-bit SR sequence, each of which defines the specifics of subset restriction of the parameter it corresponds to. In this way, it is avoided to frequently send the N-bit SR sequence each time, hence greatly reduce signaling overheads in the transmission of SR related information.

[0077] After receiving the SR related information from BSl , means 25 (not shown), called "forwarding device", of BS2 forwards this SR related information to UE3. UE3 will use this SR related information in the process of detections and gains the beneficial of detection performance and complexity.

[0078] It shall be understood for the person skilled in the art that the aforesaid devices and modules in each base station BS l , BS2 may be independent from each other. Alternatively, part or all of them may be integrated together in one apparatus, such as schedule.

[0079] Fig. 5 illustrates schematic diagram of system for assisting User Equipment to reduce interference according to another embodiment of the present invention.

[0080] As shown by Fig. 1 , UE3 in the cell of BS2 is located close to the periphery of cell of BSl , hence subjected to the interference from BSl during the downlink and uplink communication with BS2. The detailed description thereof will be made by reference Fig. 5 in connection with Fig. 1 as follows:

[0081] For assisting UE3 to cancel & suppress the downlink interference from BS1 , in BS2, means 21 , called "sending device", sends to BS 1 a request for requesting BS1 to activate a Subset Restriction (SR) operation, that is, the base station restricts some parameter related to downlink communication to a subset so as to avoid interfering other neighboring base stations.

[0082] The request may only include an indication of the existence of UE which needs Network Assisting Interference Cancellation & Suppression (NAICS), or include a definite information for requesting BS 1 to activate a SR operation. It could be understood by the person skilled in the art that the request may include other types of information for requesting BS 1 to activate a SR operation, which shall fall into the protection scope thereof and be incorporated herein by reference.

[0083] After receiving the request for SR from BS2, in means 12, called "the providing device" of BS 1 , a determining module 121 determines, based on the request, whether to activate SR. For example, once receiving the request, the determining module 121 estimates the effect to the system performance caused by a SR to be activated. The system performance comprises, but is not limited to, any combination of the performance or flexibility of its scheduler, the number of UEs it serves or its throughout capacity, and the like. If the effect does not go beyond the predefined condition, the determining module 121 then determines to activate a SR; otherwise, it determines not to activate a SR. It could be understood by the person skilled in the art that other ways for determining whether to activate a SR operation, if applicable to the present invention, shall fall into the protection scope thereof and be incorporated herein by reference.

[0084] In this way, it can provide more flexibility for the interfering base station, i.e. BS 1 , to determine whether start SR or not, hence gains a balance between the stability of system performance and provide UE with network assisting interference cancellation & suppression.

[0085] If the determining module 121 determines to activate SR, a sending module 122 in the providing device 12 sends to BS2 a SR related information as a response. It could be understood by the person skilled in the art that the SR related information may be contained in the specific fields of the message specified by the specification of existing Interfaces between two base stations, such as X2 interface, or may be carried by a new signaling over the existing or new interfaces between two base stations. It shall be understood that other ways for carrying the SR related information, if applicable to the present invention, shall fall into the protection scope thereof and be incorporated herein by reference.

[0086] In an example, the SR related information includes a N-bit SR binary sequence which is specific to the base station. Each bit of the sequence corresponds a difference parameter which could be executed a SR operation. When a bit is "1", it indicates that a SR operation is to be active to its corresponding parameter; otherwise, when the bit is "0", it means that no SR operation be activated to its corresponding parameter.

[0087] In another example, besides the a N-bit SR binary sequence, the SR related information further includes some Information Elements (IEs) corresponding to part of or all of "1" bits in the sequence. Each IE corresponds to a different "1" bit of the N-bit SR binary sequence and defines the specific information of the SR operation to the parameter which the "1" bit corresponds to. For example:

[0088] - for Transmission Mode (TM) bit of "1", its corresponding IE define the range or the specific subset of the transmission modes being restricted;

[0089] - for Physical Resource Block (PRB) bit of "1", its corresponding IE defines the number or specific subset of PRBs being restricted; [0090] - for Code Book(CB) bit of "1", its corresponding IE defines the number or the specific subset of codes in the code book being restricted.

[0091] In an alternative example, the N-bit SR sequence is static or semi-static, that is, it needs not to be updated frequently. Specifically, an interfering base station may inform its N-bit SR sequence to other base stations via a global broadcast or just send its N-bit SR sequence to other base stations once in response to the request thereof. Once received the N-bit SR sequence from the interfering base station, the other base stations maintain it in the storage device which will not be updated until receiving a new N-bit SR sequence from the same interfering base station next time. In this case, since BS2 keeps the N-bit SR sequence sent by BS 1 before, BS2 needs only to send to BS1 the IEs corresponding to part of or all of "1" bits of the N-bit SR sequence, each of which defines the specifics of subset restriction of the parameter it corresponds to. In this way, it is avoided to frequently send the N-bit SR sequence each time, hence greatly reduce signaling overheads in the transmission of SR related information.

[0092] If the determining module 121 determines not to activate SR, BS2 may send a response, such as a Non-acknowledgement (NAK) or a N-Bit SR sequence of all "0" bits to BS2, to indicate that no SR is activated. Alternatively, BS2 may also simply not send the response to BS2 to indicate to indicate that no SR is activated. It shall be understood that other ways for indicating not to activate SR, if applicable to the present invention, shall be incorporated herein by reference and fall into the protection scope thereof.

[0093] After receiving the SR related information from BS1 , means 25 (not shown), called "forwarding device", of BS2 forwards this SR related information to UE3. UE3 will use this SR related information in the process of detections and gains the beneficial of detection performance and complexity. [0094] It shall be understood for the person skilled in the art that the aforesaid devices and modules in each base station BS 1 , BS2 may be independent from each other. Alternatively, part or all of them may be integrated together in one apparatus, such as schedule.

[0095] It needs to note that the present invention can be implemented in software and/or a combination of software and hardware, for example, the invention can be implemented by using an Application Specific Integrated Circuit (ASIC), a general purpose computer or any other similar hardware equipment. In one embodiment, the software program of this invention can be executed by a processor to accomplish the aforesaid steps or functions. Likewise, the software program (including the relevant data structure) of the invention can be stored in a computer readable recording medium, for example, RAM memory, magneto-optical drive or floppy disk and similar devices. In addition, some steps or functions of the invention can be realized by using hardware, for example, a circuit that cooperates with the processor to perform various steps or functions.

[0096] In addition, part of the invention can be applied as a computer program product, such as a computer program instruction, when the instruction is executed by the computer, the method and/or technical solution according to this invention may be called or provided through an operation of the computer. However, the program instruction for calling the method of the invention may possibly be stored in a fixed or movable recording medium, and/or be transmitted via broadcasting or other signal carrier mediums, and/or be stored in the operation memory of a computer device that is running according to said program instruction. Here, there is one device included according to an embodiment of the invention, said device comprises a memory for storing computer program instructions and a processor for executing program instructions, this device is triggered to operate the methods and/or technical solutions based on the aforesaid embodiments of the invention when the computer program instructions are executed by said processor.

[0097] To those skilled in the art, apparently the present invention is not limited to the details of the aforementioned exemplary embodiments, moreover, under the premise of not deviating from the spirit or fundamental characteristics of the invention, this invention can be accomplished in other specific forms. Therefore, the embodiments should be considered exemplary and non-restrictive no matter from which point, the scope of the invention is defined by the appended claims instead of the above description, and aims at covering the meanings of the equivalent components falling into the claims and all changes within the scope in this invention. Any reference sign in the claims shall not be deemed as limiting the concerned claims. Besides, apparently the word "comprise/include" does not exclude other components or steps, singular numbers does not exclude complex numbers, the plurality of components or means mentioned in device claims may also be accomplished by one component or means through software or hardware, the wording like first and second are only used to represent names rather than any specific order.

Claims

1. An apparatus, in a base station in a wireless network, for assisting UE served by another base station to reduce interference, the apparatus comprising:

means for receiving the request for subset restriction(SR) from the serving base station;

means for, in response to the request, providing the subset restriction related information to said serving base station, wherein the subset restriction related information may comprise one or more levels of multiple-level signaling, the first level of which indicating whether to activate SR and the next levels of which indicating the specifics of SR if SR is to be activated.

2. The apparatus of claim 1 , wherein, said means for providing comprising: a determining module for determining, based on the request, whether to providing the subset restriction related information to said ; and

a sending module for sending the subset restriction related information to said serving base station, upon the determination of providing the subset restriction related information.

3. The apparatus of claim 1 or 2, wherein, the request includes indication information of the existence of a UE which needs NAICS.

4. The apparatus of anyone of claims 1 to 3, wherein, the subset restriction related information includes a first level of signaling which is a N-bit binary sequence, each bit of which is respectively assigned to indicate used to indicate the subset restriction on each difference parameter.

5. The apparatus of anyone of claim 1 to 4, wherein, the subset restriction related information further includes a second level of signaling consisting of some IEs, each of which respectively corresponds to a different bit of the N-bit binary sequence and defines the specifics of the subset restriction represented by the bit.

6. An apparatus, in a base station in a wireless network, for assisting UE served by another base station to reduce interference, the apparatus comprising:

means for sending a request for subset restriction(SR) to a interfering base station;

means for receiving the subset restriction related information sent by said interfering base station in response to the request, wherein the subset restriction related information may comprise one or more levels of multiple-level signaling, the first level of which indicating whether to activate SR and the next levels of which indicating the specifics of SR if SR is to be activated;

a forwarding device for forwarding the received subset restriction related information to an UE which needs NAICS.

7. The apparatus of claim 6, wherein, the request includes indication information of the existence of an UE which needs NAICS.

8. A method, in a base station in a wireless network, for assisting UE served y the base station itself to reduce interference, comprising:

- receiving the request for subset restriction(SR) from the serving base station;

- providing, in response to the request, the subset restriction(SR) related information to said serving base station, wherein the subset restrictioin related information may comprise one or more levels of multiple-level signaling, the first level of which indicating whether to activate SR and the next levels of which indicating the specifics of SR if SR is to be activated.

9. The method of claim 8, wherein, said step of providing comprising:

- determining, based on the request, whether to providing the subset restriction related information; and

- sending the subset restriction related information to said serving base station, upon the determination of providing the subset restriction related information.

10. The method of claim 8 or 9, wherein, the request includes indication information of the existence of a UE which needs NAICS.

11. The method of anyone of claims 8 to 10, wherein, the subset restriction related information includes a first level of signaling which is a N-bit binary sequence, each bit of which is respectively assigned to indicate used to indicate the subset restriction on each difference parameter.

12. The method of anyone of claims 8 to 11 , wherein, the subset restriction related information further includes a second level of signaling consisting of some IEs, each of which respectively corresponds to a different bit of the N-bit binary sequence and defines the specifics of the subset restriction represented by the bit..

13. A method, in a base station in a wireless network, for assisting UE served by the base station itself to reduce interference, comprising:

- sending a request for subset restriction(SR) to a interfering base station;

- receiving the subset restriction related information sent by said interfering base station in response to the request, wherein the SR related information may comprise one or more levels of multiple-level signaling, the first level of which indicating whether to activate SR and the next levels of which indicating the specifics of SR if SR is to be activated;

- forwarding the received subset restriction related information to an UE which needs NAICS.

14. The method of claim 13, wherein, the request includes indication information of the existence of an UE which needs NAICS.

15. A base station for assisting UE to reduce interference, the base station comprises the apparatus of anyone of claims 1 to 7.

16. A wireless network for assisting UE to reduce interference, comprises at least one base station of anyone of claims 1-5 and at least one base station of anyone of claims 6-7, wherein, said wireless network is a wireless network based on 3 GPP.

17. A computer-readable medium having instructions stored thereon, that, in response to execution by a computing device, cause the computing device to perform the method as defined by anyone of claims 8 to 14.