EbNo 和 EcIo 的概念与区别.docx

How to calculate ULEb/No : 上行公式为： ULEb/No=W/R.Prx/I 其中: signal receiv ed at constant power is Prx received interference power is I. due to fast feedback loop (1 500Hz) this is fairly successful. It means that for a chose service, chose channel condition and chose required BLER, the received power on the traffic channel divided by the inter fering power is approximately constant. How to calculate DLEb/No : Because the synchr onized orthogonal code reduce the interference from the serving cell (or cell ,in soft hand over) : DL theEb/No is calculated by the model: 下行公式为:Eb/No=W/R.Prx/Iown(1-)+ Ioth+Pn 其中:Where Iown is the total power received from the serving cell ,Ioth is the t otal power received from the surrounding cells, and Pn is noise power (thermal and equip ment).the factoris the call orthogonal factor, which depends on the multipath Condition. T he codes are fully orthogonal. Thus in the case of no multipath the interference from the serving cell is cancelled and=1.if there are instantaneously two equally strong propagation path, then only half of the interference is cancelled from the receiver point of view and =0.5 at this instant. Ec/I Ec/Io is received chip energy relative to the total power spectra l density. In UL this is the same asEb/No divided by the processing gain. I.e. by W/R. in DL the Io is the totol received power spectral density,thus the orthogonality effects are not taken into account. Notice that the notation of CPICH Ec/No is actually the Ec/Io of the CPICH channel.Ec/Io is typically used as a link performance indicator for the signals, which have no information bits in the usual meaning. Such signals are for, e.g., CPICH, AICH and PICH.Eb/N 举例：UL:如果 12.2 kbps voice 3km/h 4db PS 3km/h 64kbps 2db DL: 12.2 kbps voice 3km/h 6.5db PS 3km/h 64kbps db 一般在实际测试中我们都把Eb/NoEb/oEb/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,就不做这项工作了,就直接是码片序列,所以是Echip/Io而,Eb/No指的是Ebite,所说的是业务信道的信噪比,而业务信道当然有bit了,而且成帧了的,所以就叫Eb/No总结上面的废话,Ec就是导频专用,Eb就是业务信道专用1 各种符号1.1 信号符号1. C ：载波功率2. Ec：码片的能量3. Eb：业务信道上的比特能量，在95与1x上与Ec的关系为Eb=EcW/R(dB)4. Ior：DO中的概念，指有用信号的功率谱密度。 1.2 噪声干扰符号 1. I ：干扰总功率，包括热噪声，不包括有用信号功率。 2. Io ：干扰功率谱密度，包括热噪声，主要在导频信道上与Ec配合组成Ec/Io使用。 3. No Eb/No can be interpreted as the.：热噪声功率谱密度，计算公式为：10lg(KT)+Nf。（cdma系统工程手册p652）Such ratio of the total energy(including pilot, DRC and ACK) received per antenna from that mobile during an information bit to thermal noise psd.（80-H0447-1, X4 P10）4. Nt ：噪声功率谱密度，包含热噪声和干扰。（Nt. The effective noise power spectral density at the sector RF input ports.）3GPP2 C.S0032。“Fig 2.3.1 demonstrates the Ec,p/No per.Ec,p/Nt per antenna (or.Reverse Traffic Channel PER versus total antenna at 0% loading in which situation Nt = No).” “Due to the assumed geometry, Ior/Nt saturates while Ior/No - .”in 80-H0447-1, X4 5. Ioc ：其他小区和用户的干扰功率谱密度，不包括热噪声。注意：噪声（而不是热噪声）一般指的是热噪声加干扰。1.3 比值类符号1. Ec/Io：导频信道的Ec/Io，95与1x与导频信道的SNR相等。2. Ec/Nt：与Ec/Io相同，但是习惯使用Ec/Io。3. Eb/Nt：指解调门限，在没有干扰时与Eb/No相同，否则比Eb/No要小。4. Eb/No：在没有干扰（反向指0负荷）时与Eb/Nt相同，随着负荷（干扰）上升而上升。5. C/I ：载干比6. SNR：信号噪声比，SNRreq=(Eb/No)/(W/R)。7. Ior/Ioc ：用于EVDO中，指有用信号谱密度与干扰谱密度之比。8. Ior/(Ioc+No) ：用于EVDO中前向，指有用信号谱密度与噪声谱密度比值，等于C/I、SNR以及综合的Ec/Io。2 符号之间关系2.1 信号类符号1. C与Ec：C为载波功率，Ec为码片能量，在CDMA中两者关系为C=W*Ec。（此处W为码片速率）。2. Eb与Ec：95与1X中业务信道的比特能量，Eb=Ec + W/R (dB).3. Ior与Ec：Ior为有用信号的功率谱密度，是一种综合的值，与带宽W的积为总功率，从这点看与值一样，为什么不用Ec，主要是考虑到DO中前向一个时隙中各Ec值并不相同。所以Ior相当与一个综合的Ec，或者说是前向各Ec的平均。2.2 干扰类符号1. Io与Nt：都是噪声谱密度，热噪声谱密度加干扰谱密度，两者相同。Io的说法偏重于干扰，而Nt的说法偏重于噪声。2. Nt与No：Nt为热噪声谱密度加干扰谱密度，而No为热噪声谱密度。3. I与Io：I为干扰总功率（包括热噪声），而Io为干扰谱密度（包括热噪声），两者关系为I = W*Io，其中W为