资源描述：
《ebno和ecio的概念与区别》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。
1、HowtocalculateUL Eb/No:上行公式为：UL Eb/No=W/R.Prx/I其中:signalreceivedatconstantpowerisPrxreceivedinterferencepowerisI.duetofastfeedbackloop(1500Hz)thisisfairlysuccessful.Itmeansthatforachoseservice,chosechannelconditionandchoserequiredBLER,thereceivedpowe
2、ronthetrafficchanneldividedbytheinterferingpowerisapproximatelyconstant..HowtocalculateDL Eb/No:Becausethesynchronizedorthogonalcodereducetheinterferencefromtheservingcell(orcell,insofthandover):DLthe Eb/Noiscalculatedbythemodel:下行公式为:Eb/No=W/R.Prx/I
3、own(1-α)+Ioth+Pn其中:WhereIownisthetotalpowerreceivedfromtheservingcell,Iothisthetotalpowerreceivedfromthesurroundingcells,andPnisnoisepower(thermalandequipment).thefactorαisthecallorthogonalfactor,whichdependsonthemultipathCondition.Thecodesarefullyor
4、thogonal.Thusinthecaseofnomultipaththeinterferencefromtheservingcelliscancelledandα=1.ifthereareinstantaneouslytwoequallystrongpropagationpath,thenonlyhalfoftheinterferenceiscancelledfromthereceiverpointofviewandα=0.5atthisinstant.Ec/IEc/Ioisreceived
5、chipenergyrelativetothetotalpowerspectraldensity.InULthisisthesameas Eb/Nodividedbytheprocessinggain.I.e.byW/R.inDLtheIoisthetotolreceivedpowerspectraldensity,thustheorthogonalityeffectsarenottakenintoaccount.NoticethatthenotationofCPICHEc/Noisactual
6、lytheEc/IooftheCPICHchannel.Ec/Ioistypicallyusedasalinkperformanceindicatorforthesignals,whichhavenoinformationbitsintheusualmeaning.Suchsignalsarefor,e.g.,CPICH,AICHandPICH. Eb/N举例：UL:如果12.2kbpsvoice3km/h4dbPS3km/h64kbps2dbDL:12.2kbpsvoice3km/h6.5db
7、PS3km/h64kbpsdb一般在实际测试中我们都把 Eb/No＝Eb/Ｉo．Eb/No：单位比特所含的能量与单边信号功率谱密度之比EB/NO被定义成了“信噪比”这个专用名词，它是指解成数字信号后的信号与噪声的比值，每比特能量比噪声电平EC/IO也被定义了专用名词，称为“载干比”，它是指空中模拟电波中的信号与噪声的比值，每码片能量比干扰电平 在C1中移动通讯基础知识的最后几页讲了这个问题。对于CDMA系统,EC/IO小于“0”,即隐蔽性很好，因此CDMA最早被用在军事上；EB/NO在所有
8、通讯系统中都大于“0”。 理解记忆是最简单的： EC中的C是指CARRIER,它是模拟信号。 EB中的B是指BIT，对于CDMA系统实际上它是指的symbol，但它们都是数字信号。 记住,Ec/Io是导频信号的信噪比,怎么记呢,C=CHIP,码片的意思,进行快速前向功率控制的时候,MS的导频里插入个功率控制子信道来要求BS升降发射功率,但由于是快速功率控制,所以,这里的MS的导频不经过编码和调制,怕由于编码和调制成帧要花费时间,造成时延,怕产生ERROR,所以,就不做这项
