800B宽带机维修培训资料
Maintain training information of broadband machine 800B

1、800B宽带直放站原理框图：

Principle frame chart of broadband direct shoot station 800B

1原理框图

Principle frame chart

接施主天线：Connect user’s antenna
双工器： Duplexer
低噪放：Low noise power
前向中频选带单元: Unit for selecting band of former intermediate frequency
图5-1 CDMA系列无线全频直放站原理框图: Chart 5-1: Principle frame chart of wireless full

frequency direct shoot station of CDMA series

2上行增益分配

Gain distribution of upper line
下面以800B1为例。
For example as 800B1 below.
上行总增益：80±3dB

Total

gain of upper line

上行链路各模块增益测试分析：当本地监控软件的上行增益调整为0dB时，设上行输入信号为-55dBm，

在双工器上行输出口1接频谱仪测试，因为双工器的插损是2dB，所以频谱仪上正确的读数应该是-57dBm；

信号进入低噪放，因为低噪放的增益为45dB，所以信号在经过上行低噪放放大后的输出口2正确的功率

为-12dBm；信号进入功放模块，因为上行功放模块的增益为40dB，所以信号经过上行功放放大后输出口3

正确功率为28dBm；信号进入末端双工器，因为双工器的插损是2dB，所以在双工器输出口4正确的功率为

26dBm。因为设备的上行总增益为：80±3dB，所以在测试的时候，数据误差允许在3dB之内，如果测试数

据和上面的数据相差很大，建议更换相应的模块进行比较。接口如下图标示：
Test analysis of gain of each module of chain circuit of upper line: Input signal of

upper line will be set –55dBm when gain of upper line of local supervision software

has been adjusted 0dB, output exit 1 of upper line of duplexer will be connected

Spectrum Analyzer to test, for the loss for inserting is 2dB, so correct reading on

Spectrum Analyzer should be –57dBm; the correct power is –12dBm after signal has

been magnified and enter into low noise power by output exit 2 low noise power with

45dB of gain of upper line; the correct power is 28dBm after signal has been magnified

and enter into low noise power by output exit 3 low noise power with 40dB of gain of

upper line; the correct power of output exit 4 so duplexer with 2dB of loss for

inserting is 26dBm after signal has been input the end of duplexer. For total gain

of upper line of machine is 80±3dB, therefore the error scope of data is allow in

3dB when testing, if there is a big scope between data tested and above data, you

had better to replace the corresponding module to compare. Joint below:

上行增益的调整，必须以控制直放站底噪小于-120 dBm/1.23MHz为标准，否则会干扰基站，降低基站接收灵敏度。直放站的噪声系数（NF）一般为5dB，所以：
上行增益（Gup）-路径损耗（L）+设备白噪声+噪声系数≤-120dBm/1.23MHz
白噪声=-174dBm/Hz=-113dBm/1.23MHz
Gup-L+（-113）+5≤-120dBm
Gup≤L-120+113-5
Gup≤L-12
路径损耗（L）=基站发射功率（G网36dBm，C网33dBm）-直放站输入信号强度
因此直放站的上行增益小于路径损耗12dB时，就能保证直放站上行底噪了。
根据上、下行平衡依据，在室外直放站允许上、下行增益相差5dB，在室内直放站允许上、下行增益相差10dB，当上行增益确定了，下行增益范围也能计算出来，根据设备额定总的增益，再加上施主天线的增益及馈线的损耗，就能确定直放站最小输入功率。
Noise on the bottom must be control less than -120 dBm/1.23MHz when adjusting gain of upper line. Otherwise, it will interfere base station so that delicacy of base station will be descended for receiving. Noise coefficient (NF) on direct shoot station is 5dB usually, therefore: Gain of upper line (Gup)-Loss of path (L) + Empty noise of equipment + Noise coefficient ≤-120dBm/1.23MHz
Empty noise =-174dBm/Hz=-113dBm/1.23MHz
Gup-L+（-113）+5≤-120dBm
Gup≤L-120+113-5
Gup≤L-12
Loss of path (L) = Shoot power of base station (Network G is 36dBm, Network C is 38dBm)-input signal intensity of direct shoot station, noise at the bottom of upper line of direct shoot station can be ensured when gain of upper line of direct shoot station is less than 12dB of path loss, 5dB difference between upper line and down line is allowed direct shoot station of outdoor as balance between them. 10dB difference between upper line and down line is allowed direct shoot station of indoor as balance between them. The scope of gain of down line can be computed after confirmed by gain of upper line, minimum input power of direct shoot station can be confirmed as rating total gain of equipment superadds gain of user’s antenna and loss of feedback antenna.

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