[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fj96ZSDNQmtYIjlLuTSa-m-Q_5VMDaFuXdCOcRqi71f8":3},{"answer":4,"createTime":5,"id":6,"options":7,"origin":9,"question":16,"related":17,"source":28,"type":29},[],"2024-06-05 00:14:43",148789959,[8,8,8,8],"",{"count":10,"courseId":11,"courseImg":12,"courseName":13,"workId":14,"workName":15},14,"41867c427fb11b0581f89efd888a6dd1","https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F31fffd9b1ab8ed93a1abd0aec5eb6142.jpg","数字信号处理(2024)","work_33953284","第三章第二次作业","已知x(n)是实序列,x(n)的4点DFT为X(k)=[1,-j,-1,j],则X(4-k)为( )",[18,30,39,48,51,60,69,78,87,92],{"answer":19,"createTime":20,"id":21,"options":22,"question":27,"source":28,"type":29},[],"2024-06-05 00:14:42",148789945,[23,24,25,26],"X(k)=-X(k)","X(k)=-X*(k)","X(k)=X*(-k)","X(k)=X(N-k)","某离散实序列x(n)满足x(n)=x(N-n);则其频域序列X(k)有( )","v1",0,{"answer":31,"createTime":5,"id":32,"options":33,"question":38,"source":28,"type":29},[],148789950,[34,35,36,37],"X((k+l))NRN(k)","X((k-l))NRN(k)","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Feaa64f066e71eec068b247ea05b1f27d.webp\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fa0d21a6ef4c0df7f1efef124815e1ca5.webp\">","已知N点有限长序列X(k)=DFT[x(n)],0≤n,k≤N,则N点DFT[\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F115b3f53fb1920a2be1b240d25ca3ab3.webp\">x(n)]=",{"answer":40,"createTime":5,"id":41,"options":42,"question":47,"source":28,"type":29},[],148789955,[43,44,45,46],"Xep(n)+Xop(n)","Xep(n)+Xop(N-n)","Xep(n)-Xop(n)","Xep(n)-Xop(N-n)","有限长序列x(n)=Xep(n)+Xop(n), 0≤n≤N-1,则X*(N-n)=",{"answer":49,"createTime":5,"id":6,"options":50,"question":16,"source":28,"type":29},[],[8,8,8,8],{"answer":52,"createTime":5,"id":53,"options":54,"question":59,"source":28,"type":29},[],148789964,[55,56,57,58],"共轭对称分量","共轭反对称分量","偶对称分量","奇对称分量","X(k)=XR(k)+jXI(k),0≤k≤N-1,则IDFT[XR(k)]是x(n)的( )",{"answer":61,"createTime":5,"id":62,"options":63,"question":68,"source":28,"type":29},[],148789969,[64,65,66,67],"收敛,等间隔采样","N点有限长,N点等间隔采样","N点有限长,取值","无限长,N点等间隔采样","DFT的物理意义是:一个 的离散序列x(n)的离散傅里叶变换X(k)为x(n)的傅里叶变换X(ejω)在区间[0,2π]上的",{"answer":70,"createTime":5,"id":71,"options":72,"question":77,"source":28,"type":29},[],148789974,[73,74,75,76],"N越大","N越小","N=32","N=64","用DFT对一个32点的离散信号进行谱分析,其谱分辨率决定于谱采样的点数N,即 ,分辨率越高",{"answer":79,"createTime":5,"id":80,"options":81,"question":86,"source":28,"type":29},[],148789979,[82,83,84,85],"N1=3,N2=4","N1=5,N2=4","N1=4,N2=4","N1=5,N2=5","对x1(n) (0≤n≤N1-1 )和x2(n) (0≤n≤N2-1 )进行8点的圆周卷积,其中 的结果不等于线性卷积",{"answer":88,"createTime":5,"id":89,"options":90,"question":91,"source":28,"type":29},[],148789982,[8,8,8,8],"对5点有限长序列[1,3,0,5,2]进行向右1点圆周以为后得到的序列( )",{"answer":93,"createTime":5,"id":94,"options":95,"question":100,"source":28,"type":29},[],148789985,[96,97,98,99],"频谱泄露","时域混叠","频谱混叠","谱间干扰","序列x(n)长度为M,当频率采样点数N<M时,由频率采样X(k)恢复原序列x(n)时会产生( )现象"]