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LucentTechnologiesBellLabsInnovations1WirelessNetworksGroupLucentTechnologiesProprietaryCDMA系统无线设计勘察吴晓庆朗讯无线设计优化部LucentTechnologiesBellLabsInnovations2WirelessNetworksGroupLucentTechnologiesProprietary内容站址勘察系统隔离GPS天线选位LucentTechnologiesBellLabsInnovations3WirelessNetworksGroupLucentTechnologiesProprietary站址勘察LucentTechnologiesBellLabsInnovations4WirelessNetworksGroupLucentTechnologiesProprietary0°Tx/Rx50°downtilt3°Tx/Rx220°downtilt3°Tx/Rx320°downtilt3°Height40mTx/RxTx/Rx31Tx/RxCDMA基站GPS天线基站天线LucentTechnologiesBellLabsInnovations5WirelessNetworksGroupLucentTechnologiesProprietary站址勘察勘察目的：确定基站站址确定基站天线位置了解站址周边地貌LucentTechnologiesBellLabsInnovations6WirelessNetworksGroupLucentTechnologiesProprietary站址勘察站址是无线覆盖的主要因素站址由覆盖目标而定站址建筑应比周围建筑高4-5米如站址是楼房，最好选办公楼，避免居民楼LucentTechnologiesBellLabsInnovations7WirelessNetworksGroupLucentTechnologiesProprietary基站天线基站天线分为：1。定向天线，用于定向站(3扇区，2扇区站)2。全向天线，用于全向站。市区不应有全向站，市郊全向站应远离市区2.5-3公里。全向站应远离两市边界2公里(以利于两市业务分开)。LucentTechnologiesBellLabsInnovations8WirelessNetworksGroupLucentTechnologiesProprietary基站天线基站天线的主要参数：1.天线增益dBd:以耦极子天线为基准测得的增益dBi:以等方向天线为基准测得的增益dBi=dBd+2.2dB2.半功率角(主波瓣3dB宽度)水平半功率角：65度，90度垂直半功率角：7度，9度等3.前后向增益比：LucentTechnologiesBellLabsInnovations9WirelessNetworksGroupLucentTechnologiesProprietary天线方向图LucentTechnologiesBellLabsInnovations10WirelessNetworksGroupLucentTechnologiesProprietary基站天线分集方式为保证信号良好接收，基站天线需分集接收垂直极化天线--需空间分集接收，每扇区需两副接收天线，一般两天线间隔4米双极化天线--不需空间分集，每扇区需一副接收天线。LucentTechnologiesBellLabsInnovations11WirelessNetworksGroupLucentTechnologiesProprietary基站天线选位基站天线选位，应考虑：天线挂高：天线中心位置距地面高度.天线方位角：天线主瓣水平指向天线下倾角：天线主瓣垂直指向倾角包括机械和电子倾角。电子倾角天线由于其方向图变形小，多用在需较大倾角(10度以上)应用上。LucentTechnologiesBellLabsInnovations12WirelessNetworksGroupLucentTechnologiesProprietary天线挂高在市区中，天线挂高应大致一致一般城市，平均挂高35米大城市，平均挂高40-45米且天线高度落差应小于12-15米。郊区天线可较高，以获得大覆盖。LucentTechnologiesBellLabsInnovations13WirelessNetworksGroupLucentTechnologiesProprietary天线方位角天线方位角主要由用户所需覆盖方向而定设计或地图上的方向角以正北为基准，指南针测得为以磁北为基准，对于中国地理位置，正北与磁北偏差可忽略。天线方位角可任意角度(与GSM不一样。)，但两扇区的夹角也不应太小(不小于80度)。测量方位角应使用防磁指南针。天线方位角指向区域应无近距离(50米内)阻挡物。LucentTechnologiesBellLabsInnovations14WirelessNetworksGroupLucentTechnologiesProprietary天线倾角天线下倾角包括：机械倾角+内置电子倾角。通常不使用带电子倾角的天线。但勘察时，对需较大下倾角(10度以上)的站址(一般在市区较高建筑)，应使用带电子倾角的天线。安装时，机械倾角的误差应在0.5度以内。LucentTechnologiesBellLabsInnovations15WirelessNetworksGroupLucentTechnologiesProprietary地貌•地貌大致分五类密集市区：高楼商厦(20层以上)云集区域市区：一般市区，偶有高楼但较分散。郊区，县城，大镇：楼房6层左右远郊，小镇：楼房2-6层。旷野，农村，公路站：楼房较少，并分散。LucentTechnologiesBellLabsInnovations16WirelessNetworksGroupLucentTechnologiesProprietary密集市区LucentTechnologiesBellLabsInnovations17WirelessNetworksGroupLucentTechnologiesProprietary市区LucentTechnologiesBellLabsInnovations18WirelessNetworksGroupLucentTechnologiesProprietary远郊区LucentTechnologiesBellLabsInnovations19WirelessNetworksGroupLucentTechnologiesProprietary农村LucentTechnologiesBellLabsInnovations20WirelessNetworksGroupLucentTechnologiesProprietary系统间隔离主要讨论CDMA与联通GSM系统之间的隔离。LucentTechnologiesBellLabsInnovations21WirelessNetworksGroupLucentTechnologiesProprietary干扰示意图放大器干扰系统的Tx滤波器被干扰系统的接收机隔离发射机的载波及干扰波接收到的干扰波AB干扰系统(CDMA)被干扰系统(GSM)880MHz870MHz915MHz909MHzCDMA基站发射联通GSM基站接收878.49MHzLucentTechnologiesBellLabsInnovations22WirelessNetworksGroupLucentTechnologiesProprietary系统间隔离系统间隔离可采用垂直隔离，或水平隔离水平隔离CDMA天线GSM天线垂直隔离GSM天线CDMA天线LucentTechnologiesBellLabsInnovations23WirelessNetworksGroupLucentTechnologiesProprietary联通CDMA与GSM共站系统之间的隔离1.CDMA和GSM共站时，采用天线垂直隔离,约需0.6米2.CDMA和GSM共站时，天线水平隔离约需2.2米(两天线平行放置G_tx+G_rx=0)LucentTechnologiesBellLabsInnovations24WirelessNetworksGroupLucentTechnologiesProprietary共站水平隔离--两天线非平行放置CDMA天线GSM天线如两天线需非平行放置，尽量避免两天线指向交叉，即应使两天线背面相对(如上)。如果发生指向交叉(即CDMA天线在左，两天线正面相对)，应使隔离加大(如5米以上)。LucentTechnologiesBellLabsInnovations25WirelessNetworksGroupLucentTechnologiesProprietary联通CDMA系统与GSM系统不共站不共站时，最坏情况之下(两系统天线正对互打),则视天线增益而定a.G_tx+G_rx=30(市区或郊区定向站),CDMA和GSM需相距68米b.G_tx+G_rx=36(郊区或乡村定向站),CDMA和GSM需相距135米c.G_tx+G_rx=20(全向站),CDMA和GSM需相距22米LucentTechnologiesBellLabsInnovations26WirelessNetworksGroupLucentTechnologiesProprietaryCDMA与ETACS间干扰由于ETACS系统基站接收频率最低可到882MHz,与CDMA基站第一载频发射878.49MHz相距较近。其系统间干扰比CDMA与GSM间复杂。虽然，中国电信已宣布2001年6月关闭所有模拟网(包括ETACS)，但仍应注意各城市的ETACS情况。LucentTechnologiesBellLabsInnovations27WirelessNetworksGroupLucentTechnologiesProprietaryGPS天线选位LucentTechnologiesBellLabsInnovations28WirelessNetworksGroupLucentTechnologiesProprietaryGPS天线选位为使GPS天线能够收到GPS卫星的信号，GPS天线不能受到阻挡，使之可以与4颗GPS卫星保持无阻挡连接。GPS天线用于接收GPS卫星信号，以为基站提供定时。如用手持GPS接收机测试，其显示应有4条实心黑柱。LucentTechnologiesBellLabsInnovations29WirelessNetworksGroupLucentTechnologiesProprietaryGPS天线选位如果不能做到完全无阻挡，应尽量找一个位置使GPS周围10度以上半球体的视线区域内的阻挡应小于25%。且该25%阻挡应分布在两个1/4的球体中。LucentTechnologiesBellLabsInnovations30WirelessNetworksGroupLucentTechnologiesProprietaryGPS天线选位LucentTechnologiesBellLabsInnovations31WirelessNetworksGroupLucentTechnologiesProprietaryGPS天线选位GPSABCLA+LB+LC10度仰角圆0度仰角圆10度仰角圆周长25%LucentTechnologiesBellLabsInnovations32WirelessNetworksGroupLucentTechnologiesProprietaryGPS天线选位正确错误LucentTechnologiesBellLabsInnovations33WirelessNetworksGroupLucentTechnologiesProprietaryGPS应垂直于水平面误差应在±2度以内。正确错误Luc