English:
[0003] CSG cells provide member users with specialized services and the general expectation is that the coverage area of a CSG cell is large enough to accommodate its member users. For example, the coverage areas of the CSG cell may be sufficiently large to accommodate users in a home environment. However, if a CSG cell is located too near a macro cell, the macro cell could be the stronger cell when the UE is within the intended coverage area of the CSG cell. This issue may arise, for example, if the CSG cell is within approximately 100-150 meters or more from a macro cell site depending on the relative transmit powers of the macro and CGS cells. The result is a potentially unacceptably small coverage area for the CSG cell, making deployment of CSG cells within a certain radius of the macro cell site impractical. In order to prevent this undesirable effect, it is necessary to be able handover a UE to the CSG cell even when the CSG cell is not the strongest cell.
[0004] One consequence of handover of a UE to a CSG cell that is not the strongest cell is that downlink interference from the strongest cell and uplink interference to the strongest cell can be significant. FIG. 1 illustrates uplink interference caused by a UE in such a scenario. The CSG UE 102 is connected to a CSG cell 104 although a signal from a macro cell base station 106 is stronger than the signal from the CSG cell. In FIG. 1, uplink transmissions from the CSG UE 102 can cause uplink interference to macro cell UEs, for example, to UEl and UE2. The macro cell ensures orthogonality of uplink transmissions of UEs connected to the macro cell. That is, the macro cell performs resource allocation such that macro cell UEs do not cause uplink interference with each other. The uplink transmissions to different cells, for example, transmissions from the CSG UE 102 to the neighboring CSG cell 104 in FIG. 1, however cannot be orthogonalized relative to transmissions in the macro cell. Thus UE transmissions to the CSG cell can cause significant uplink interference to macro cell UEs.
[0005] The various aspects, features and advantages of the invention will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Detailed Description thereof with the accompanying drawings described below. The drawings may have been simplified for clarity and are not necessarily drawn to scale.
[0006] FIG. 1 is a prior art illustration of a portion of a wireless communication system including a macro cell and a neighboring micro cell.
[0007] FIG. 2 illustrates a first process flow diagram.
[0008] FIG. 3 illustrates a first process flow diagram.
[0009] FIG. 4 illustrates a first process flow diagram.
[0010] FIG. 5 illustrates a first process flow diagram.
[0011] FIG. 6 illustrates another process flow diagram.
[0012] According to one aspect of the disclosure, generally, the transmit power of a wireless communication device, also referred to herein as user equipment (UE), connected to a serving cell is reduced to avoid or at least reduce interference with uplink transmissions by neighboring UE, using the same or overlapping radio resources, connected to a neighboring cell. In FIG. 1, for example, the CSG cell 104 is located proximate or near a macro cell 106 such that uplink transmissions from a UE 102 connected to the CSG cell 104 may interfere with uplink transmissions from UE 107 and UE 108, using the same or overlapping radio resources, connected to the neighboring macro cell 106. To mitigate this problem, in some instances, the maximum transmit power of the UE 102 connected to the CSG cell 104 is reduced to avoid or at least reduce interference with UE 107 and UE 108 connected to macro cell 106.
[0013] The following equation can be used to determine the maximum allowable transmit power of the CSG UE 102:

中文:
[0003]CSG小区为成员用户提供专用服务,并且通常期望CSG小区的覆盖范围大得足以容纳其成员用户。例如,CSG小区的覆盖范围可以大得足以容纳归属环境中的用户。然而,如果CSG小区过于接近宏小区,则当UE在CSG小区的预期覆盖范围内时,宏小区可能是较强小区。例如,根据宏小区和CSG小区的相对发射功率,如果CSG小区在距宏小区站点约100-150米或更多距离内,则该问题可能产生。结果是对于CSG小区的可能无法接受的小覆盖范围,使得CSG小区在宏小区站点的特定半径内的布置是不切实际的。为了防止该不期望的效果,即使当CSG小区不是最强小区时,也有必要能够将UE切换到CSG小区。
[0004]UE到不是最强小区的CSG小区的切换的一个结果是,来自最强小区的下行链路干扰和对最强小区的上行链路干扰可能是显著的。图1图示了在这样的情况下由UE造成的上行链路干扰。虽然来自宏小区基站106的信号比来自CSG小区的信号更强,但是CSG UE 102被连接到CSG小区104。在图1中,来自CSG UE 102的上行链路传输可能导致对例如UE1和UE2的宏小区UE的上行链路干扰。宏小区确保连接到宏小区的UE的上行链路传输的正交性。即,宏小区执行资源分配,使得宏小区UE不会导致彼此之间的上行链路干扰。然而,对不同小区的上行链路传输,例如,在图1中从CSG UE 102到相邻CSG小区104的传输,可能不能相对于宏小区中的传输被正交化。因此,对CSG小区的UE传输可能导致对宏小区UE的显著上行链路干扰。
[0005]当认真考虑以下描述的下面的具体实施方式以及附图时,本发明的各种方面、特征和优点对于本领域普通技术人员来说将变得更加显而易见。为了清楚起见,附图可以被简化并且不必按比例绘制。
[0006]图1是包括宏小区和相邻微小区的无线通信系统的一部分的现有技术的图示。
[0007]图2图示了第一过程流程图。
[0008]图3图示了第一过程流程图。
[0009]图4图示了第一过程流程图。
[0010]图5图示了第一过程流程图。
[0011]图6图示了另一过程流程图。
[0012]根据本公开的一个方面,通常,减小连接到服务小区的无线通信设备(在此还称为用户设备(UE))的发射功率以避免或者至少减小由连接到相邻小区的使用相同或重叠无线电资源的相邻UE所导致的对上行链路传输的干扰。在图1中,例如,CSG小区104被定位为接近宏小区104或在宏小区106附近,使得来自连接到CSG小区104的UE 102的上行链路传输可能与来自连接到相邻宏小区106的使用相同或重叠无线电资源的UE 107和UE 108的上行链路传输发生干扰。为了减轻该问题,在一些情况下,减小连接到CSG小区104的UE 102的最大发射功率,以避免或者至少减小与连接至宏小区106的UE 107和UE 108的干扰。
[0013]可以使用以下等式来确定CSG UE 102的最大允许发射功率: