南漂港城人♂
殘月灬冷影
95后南漂程序猿
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京东一个退货处理了20天,都没完成流程 客服更是厉害,全是套话,尽快帮你处理,需要处理20天吗,,app已卸载,不要给我打电话了
我发表了一篇视频贴,大伙来看看吧~
新街口灯光秀
感觉是江苏去年房价涨得最凶的城市
关于是否回老家发展
美区应用推荐一波。。
皮炎所专家门诊是不是都要你们去旁边的协宁买护肤品? 皮炎所专家门诊是不是都要你们去旁边的协宁买护肤品?
怕是C9和EDG争着给SKT送钱了。 怕是C9和EDG争着给SKT送钱了。
学长学姐们,帮我看看怎么根据qpsk仿真更改为oqpsk 下面是qpsk主程序代码 T=1; % 基带信号宽度,也就是频率 fc=10/T; % 载波频率 ml=2; % 调制信号类型的一个标志位(选取2的原因见23行) nb=100; % 传输的比特数 delta_T=T/200; % 采样间隔 fs=1/delta_T; % 采样频率 SNR=0; % 信噪比 t=0:delta_T:nb*T-delta_T; % 限定t的取值范围 N=length(t); % 采样数 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%% 调制部分 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % 基带信号的产生 data=randn(1,nb)>0.5; % 调用一个随机函数(0 or 1),输出到一个1*100的矩阵 datanrz=data.*2-1; % 变成极性码 data1=zeros(1,nb/delta_T); % 创建一个1*nb/delta_T的零矩阵 for q=1:nb data1((q-1)/delta_T+1:q/delta_T)=datanrz(q); % 将极性码变成对应的波形信号 end % 将基带信号变换成对应波形信号 data0=zeros(1,nb/delta_T); % 创建一个1*nb/delta_T的零矩阵 for q=1:nb data0((q-1)/delta_T+1:q/delta_T)=data(q); % 将极性码变成对应的波形信号 end % 发射的信号 data2=abs(fft(data1)); % 串并转换,将奇偶位数据分开 idata=datanrz(1:ml:(nb-1)); % 将奇偶位分开,因此间隔m1为2 qdata=datanrz(2:ml:nb); % QPSK信号的调制 ich=zeros(1,nb/delta_T/2); % 创建一个1*nb/delta_T/2的零矩阵,以便后面存放奇偶位数据 for i=1:nb/2 ich((i-1)/delta_T+1:i/delta_T)=idata(i); end for ii=1:N/2 a(ii)=sqrt(2/T)*cos(2*pi*fc*t(ii)); end idata1=ich.*a; % 奇数位数据与余弦函数相乘,得到一路的调制信号 qch=zeros(1,nb/2/delta_T); for j1=1:nb/2 qch((j1-1)/delta_T+1:j1/delta_T)=qdata(j1); end for jj=1:N/2 b(jj)=sqrt(2/T)*sin(2*pi*fc*t(jj)); end qdata1=qch.*b; % 偶数位数据与余弦函数相乘,得到另一路的调制信号 s=idata1+qdata1; % 将奇偶位数据合并,s即为QPSK调制信号 ss=abs(fft(s)); % 快速傅里叶变换得到频谱 %%%%%%%%%%%%%%%%%%%%%%%%%% % 高斯信道 s1=awgn(s,SNR); % 通过高斯信道之后的信号 s11=abs(fft(s1)); % 快速傅里叶变换得到频谱 s111=s1-s; % 高斯噪声曲线 %%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%% QPSK 解调部分 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % 解调部分(高斯信道) idata2=s1.*a; % 这里面其实隐藏了一个串并转换的过程 qdata2=s1.*b; % 对应的信号与正余弦信号相乘 idata3=zeros(1,nb/2); % 建立1*nb数组,以存放解调之后的信号 qdata3=zeros(1,nb/2); % 抽样判决的过程,与0作比较,data>=0,则置1,否则置0 for n=1:nb/2 % A1(n)=sum(idata2((n-1)/delta_T+1:n/delta_T)); if sum(idata2((n-1)/delta_T+1:n/delta_T))>=0 idata3(n)=1; else idata3(n)=0; end % A2(n)=sum(qdata2((n-1)/delta_T+1:n/delta_T)); if sum(qdata2((n-1)/delta_T+1:n/delta_T))>=0 qdata3(n)=1; else qdata3(n)=0; end end % 为了显示星座图,将信号进行处理 idata4=zeros(1,nb/2); qdata4=zeros(1,nb/2); for n=1:nb/2 Awgn_ichsum(n)=sum(idata2((n-1)/delta_T+1:n/delta_T))*delta_T; if Awgn_ichsum(n)>=0 idata4(n)=1; else idata4(n)=0; end Awgn_qchsum(n)=sum(qdata2((n-1)/delta_T+1:n/delta_T))*delta_T; if Awgn_qchsum(n)>=0 qdata4(n)=1; else qdata4(n)=0; end end % 将判决之后的数据存放进数组 demodata=zeros(1,nb); demodata(1:ml:(nb-1))=idata3; % 存放奇数位 demodata(2:ml:nb)=qdata3; % 存放偶数位 %为了显示,将它变成波形信号(即传输一个1代表单位宽度的高电平) demodata1=zeros(1,nb/delta_T); % 创建一个1*nb/delta_T的零矩阵 for q=1:nb demodata1((q-1)/delta_T+1:q/delta_T)=demodata(q); % 将极性码变成对应的波形信号 end % 累计误码数 % abs(demodata-data)求接收端和发射端 % 数据差的绝对值,累计之后就是误码个数 Awgn_num_BER=sum(abs(demodata-data)) %%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% 误码率计算 %% 调用了cm_sm32();和cm_sm33()函数 %%声明: 函数声明在另外俩个M文件中 %%作用: cm_sm32()用于瑞利信道误码率的计算 %% cm_sm33()用于高斯信道误码率的计算 %% ecoh on/off 作用在于决定是否显示指令内容 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% SNRindB1=0:1:6; SNRindB2=0:0.1:6; % 高斯信道 echo on; for i=1:length(SNRindB1), [pb1,ps1]=cm_sm33(SNRindB1(i)); smld_bit_awgn_err_prb(i)=pb1; smld_symbol_awgn_err_prb(i)=ps1; disp([ps1,pb1]); echo off; end; % 理论曲线 echo on; for i=1:length(SNRindB2), SNR=exp(SNRindB2(i)*log(10)/10); % 信噪比 theo_err_awgn_prb(i)=0.5*erfc(sqrt(SNR)); % 高斯噪声理论误码率 theo_err_ray_prb(i)=0.5*(1-1/sqrt(1+1/SNR)); % 瑞利衰落信道理论误码率 echo off; end; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% h = spectrum.welch; % 类似于C语言的宏定义,方便以下的调用 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%% 输出显示部分 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % 第一部分(理想) figure(1) subplot(2,2,1); plot(data0),title('基带信号'); axis([0 20000 -2 2]); subplot(2,2,2); psd(h,data1,'fs',fs),title('基带信号功率谱密度'); subplot(2,2,3); plot(s),title('调制信号'); axis([0 500 -3 3]); subplot(2,2,4); psd(h,s,'fs',fs),title('调制信号功率谱密度'); figure(2) subplot(2,2,1); plot(data0),title('基带信号'); axis([0 20000 -2 2]); subplot(2,2,2); psd(h,data1,'fs',fs),title('基带信号功率谱密度'); subplot(2,2,3); plot(demodata1),title('解调信号'); axis([0 20000 -2 2]); subplot(2,2,4); psd(h,demodata1,'fs',fs),title('解调信号功率谱密度'); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % 通过高斯信道 figure(3) subplot(2,2,1); plot(s1),title('调制信号(Awgn)'); axis([0 500 -5 5]); subplot(2,2,2); psd(h,s1,'fs',fs),title('调制信号功率谱密度(Awgn)'); subplot(2,2,3); plot(s111),title('高斯噪声'); axis([0 2000 -5 5]); subplot(2,2,4); psd(h,s11,'fs',fs),title('高斯噪声功率谱密度'); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %高斯信道下qpsk信号的理论曲线与仿真曲线 figure(4) subplot(1,2,1); for i=1:nb/2 plot(idata(i),qdata(i),'r+'),title('QPSK信号星座图(Awgn)');hold on; axis([-2 2 -2 2]); plot(Awgn_ichsum(i),Awgn_qchsum(i),'*');hold on; legend('理论值(发射端)','实际值(接收端)'); end subplot(1,2,2) semilogy(SNRindB2,theo_err_awgn_prb,'r'),title('误码率曲线');hold on; semilogy(SNRindB1,smld_bit_awgn_err_prb,'r*');hold on; xlabel('Eb/No');ylabel('BER'); legend('理论AWGN','仿真AWGN');
路过贵校,好多妹子^_^ 周六来贾汪参加考试,公交上站断了腿打车到你们学校附近打印准考证(楼主忘记了😂)顺便吃晚饭,发现你们学校妹子好多真是贾汪一道亮丽的风景线
明天考科目二,好紧张 今天去模拟效果也不怎么好,好紧张啊
新人求助 哪位学长学姐,师哥师姐,有广告鉴赏的论文啊,要求是2000字,关于一个视频广告的分析,任何广告都可以,在此谢谢了,求助攻啊
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