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无线通信课件.zip

第1章：绪论

1.1 ！！无线通信系统的基本构成。（简答1）

  1. ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593398832131-6372587b-ec5c-4672-8522-6e1930dfba8f.png#align=left&display=inline&height=178&margin=%5Bobject%20Object%5D&name=image.png&originHeight=296&originWidth=756&size=74191&status=done&style=none&width=455)作业有描述<br />    ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593399223238-8bfc8fea-51c4-4f3c-81fd-ea79c24f28c5.png#align=left&display=inline&height=447&margin=%5Bobject%20Object%5D&name=image.png&originHeight=802&originWidth=959&size=788888&status=done&style=none&width=535)

1.2 全双工技术有哪些？

时分双工(TDD)和频分双工(FDD)

1.3 数字通信系统可靠性、有效性包含哪些指标？

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1.4 3G 标准有哪些？

image.png（欧洲、美国、中国）

第二章无线通信基础

2.1影响小尺度衰落的两大效应？

  1. ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593399635820-d3be93b4-396f-4422-9c21-5fdb1ff67f85.png#align=left&display=inline&height=76&margin=%5Bobject%20Object%5D&name=image.png&originHeight=152&originWidth=632&size=37247&status=done&style=none&width=316)

2.2衰落信道分类。

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2.3！！多普勒频移的计算。 （计算1）

  1. ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593399719980-ea392593-7d0b-487f-94f5-de166d3978fe.png#align=left&display=inline&height=282&margin=%5Bobject%20Object%5D&name=image.png&originHeight=456&originWidth=922&size=154589&status=done&style=none&width=570)<br />        ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593399740501-6df040e1-0c4b-4a21-a792-ec1e3b958cfc.png#align=left&display=inline&height=160&margin=%5Bobject%20Object%5D&name=image.png&originHeight=260&originWidth=913&size=79746&status=done&style=none&width=561)<br />        ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593399762696-ee5ba3f0-499b-46c0-b343-ebb6c4b6b91a.png#align=left&display=inline&height=223&margin=%5Bobject%20Object%5D&name=image.png&originHeight=324&originWidth=898&size=94069&status=done&style=none&width=619)<br />        ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593399782270-ebe42b48-df5c-49e4-bc0e-b0581fbba4eb.png#align=left&display=inline&height=224&margin=%5Bobject%20Object%5D&name=image.png&originHeight=330&originWidth=899&size=123433&status=done&style=none&width=609)<br />        ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593399836143-c4cc2359-6856-4746-8049-9d1d31283f7d.png#align=left&display=inline&height=138&margin=%5Bobject%20Object%5D&name=image.png&originHeight=210&originWidth=916&size=86653&status=done&style=none&width=603)<br />            ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593656811570-77a7b501-d981-460e-bacf-af1d60f5bbbc.png#align=left&display=inline&height=250&margin=%5Bobject%20Object%5D&name=image.png&originHeight=499&originWidth=903&size=683459&status=done&style=none&width=451.5)

3！！.仿真（简答2）（计算2）

3.1调制星座

  1. ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593657230904-e784c64b-5114-478e-aeb7-f101517f1712.png#align=left&display=inline&height=340&margin=%5Bobject%20Object%5D&name=image.png&originHeight=680&originWidth=817&size=92624&status=done&style=none&width=408.5)
  1. %%%%%%%%%%%%% 将比特序列映射成N个QPSK信号 %%%%%%%%%%%%%
  2. q1=0+0*i;    %5pi/4 
  3. q2=0+1*i;    %3pi/4
  4. q3=1+1*i;    %pi/4
  5. q4=1+0*i;    %7pi/4
  6. sig=zeros(1,len); % sig表示原始信号
  7. for i=1: len      %将比特序列映射成QPSK信号
  8.     x=sqrt(2)/2; y=sqrt(2)/2; 
  9.     if (s(i)==q1)
  10.        sig(i)=-x-y*1i; 
  11.     end
  12.     if (s(i)==q2)
  13.        sig(i)=-x+y*1i; 
  14.     end
  15.     if (s(i)==q3)
  16.        sig(i)=x+y*1i; 
  17.     end
  18.     if (s(i)==q4)
  19.        sig(i)=x-y*1i; 
  20.     end
  21. end

3.2瑞利信道

  1.     ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593401994743-38df0f1d-83a4-46f1-950c-b6156fe9a804.png#align=left&display=inline&height=315&margin=%5Bobject%20Object%5D&name=image.png&originHeight=629&originWidth=709&size=59610&status=done&style=none&width=354.5)<br />    ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593401977132-e61b5487-6f05-464b-af76-49102a10464f.png#align=left&display=inline&height=265&margin=%5Bobject%20Object%5D&name=image.png&originHeight=530&originWidth=912&size=108548&status=done&style=none&width=456)

3.3!!!AWGN最大似然检测

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  1. distance=zeros(4,1);         %表示距离
  2. detect=zeros(len,1);         %检测值
  3. BEP=zeros(1,length(SNR_db)); %表示不同信噪比下的误码率
  4. text =zeros(4,1);            %理论上的发射机星座点
  5. text(1)=-(sqrt(2)/2)-1i*(sqrt(2)/2);
  6. text(2)=-(sqrt(2)/2)+1i*(sqrt(2)/2);
  7. text(3)=(sqrt(2)/2)+1i*(sqrt(2)/2);
  8. text(4)=(sqrt(2)/2)-1i*(sqrt(2)/2);
  9. %%%%%%%%%%%%% 用最小欧式距准则检测符号序列 %%%%%%%%%%%%%
  10.     for t = 1: len %循环所有的信号
  11.         for w = 1:4 % 检查距离
  12.             distance(w) = norm(Y(t) - H(t)*text(w))^2;%接收到的信号到所有星座点的距离
  13.         end
  14.         position= find(distance == min(distance));%找到最小距离的的位置     
  15.         detect(t) = text(position);  %解调后的符号            
  16.         if (detect(t)~= sig(t))  %计算错误个数
  17.             error = error + 1;      
  18.         end  
  19.     end
  20.     BEP(p) = error/ len;  %QPSK仿真的误码率

第 3 章：均衡、分集与多天线通信技术

3.1抗衰落技术有哪些？

  1.     ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593400901338-23148153-7064-42ab-87bb-ec959b3383bb.png#align=left&display=inline&height=198&margin=%5Bobject%20Object%5D&name=image.png&originHeight=312&originWidth=904&size=99538&status=done&style=none&width=573)

3.2！！信息量、信息熵、香农公式（计算3）

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SNR_w=10.^(SNR_db(p)/10); %单位转换：dB转w
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SNR_db=10log(SNR_w)=103=30
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3.3MIMO 和 OFDM 技术解决了什么问题？

  1. ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593415983569-40a42457-dc8e-4d19-88ef-a6a504890ba4.png#align=left&display=inline&height=114&margin=%5Bobject%20Object%5D&name=image.png&originHeight=228&originWidth=187&size=14969&status=done&style=none&width=93.5)

3.4!!!!!Alamouti 发射、接收方案 （简答3）

1.单副接受天线
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2.两副接受天线

第 4 章：移动通信网络技术

4.1 信道分配策略有哪些

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4.2 蜂窝系统核心思想是什么，用来干什么

  1. ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593400619073-5adc64a3-2e46-42e5-bef3-9860a1822b23.png#align=left&display=inline&height=52&margin=%5Bobject%20Object%5D&name=image.png&originHeight=80&originWidth=878&size=35398&status=done&style=none&width=572)

4.3 蜂窝系统区群小区数

  1. ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593656930283-aa4f0151-9870-416c-b801-852c3eb28f9e.png#align=left&display=inline&height=75&margin=%5Bobject%20Object%5D&name=image.png&originHeight=136&originWidth=839&size=46765&status=done&style=none&width=461)<br />    ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593400752351-d3faf43d-c8d4-4872-8f6d-93ff0a4e4b0e.png#align=left&display=inline&height=242&margin=%5Bobject%20Object%5D&name=image.png&originHeight=410&originWidth=909&size=120487&status=done&style=none&width=537)

4.4 区群中满足同频干扰条件下小区数的确定

  1.     ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593400865549-46c98f53-cddb-48de-9cc4-73efa2ee8136.png#align=left&display=inline&height=76&margin=%5Bobject%20Object%5D&name=image.png&originHeight=118&originWidth=667&size=25722&status=done&style=none&width=432)<br />    ![image.png](https://cdn.nlark.com/yuque/0/2020/png/1238082/1593400833266-f21a52fe-d835-4e73-96e8-c100927540a2.png#align=left&display=inline&height=149&margin=%5Bobject%20Object%5D&name=image.png&originHeight=242&originWidth=879&size=46885&status=done&style=none&width=543)

第 5 章：无线通信系统与网络

5.1LTE 多址技术

1.LTE支持双工方式：FDD和TDD
2.空中接口常用以OFDM(正交频分复用技术)为基础的多址方式，
下行多址采用OFDMA ,上行多址采用SC-FDMA