[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fbuWFqoLGmPUxnLo4HHfyCvBru8CTewVJlNcST1d0nOs":3},{"answer":4,"createTime":5,"id":6,"options":7,"origin":12,"question":16,"related":17,"source":27,"type":46},[],"2026-05-19 12:49:17",377544551,[8,9,10,11],"4","5","6","3",{"courseId":13,"courseImg":14,"courseName":15},"53e1d2ef4961cca8eea3e23969ad2cb9","https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F03a579384a6dc297c89809b582fcc767.png","默认课程","In the FFT operation flow chart of decimation-in-time with \u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F847d3ed5e456dab358628395cbcd122f.png\">, ( ) stages of butterfly operation are needed from\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fe1f9adf229f6193b63cccc32b46b8cea.png\">to\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Ff04bffd0d50d71de762446d39c0fc823.png\">",[18,29,38,47,56,65,74,83,92,101],{"answer":19,"createTime":5,"id":20,"options":21,"question":26,"source":27,"type":28},[],377544542,[22,23,24,25],"\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F31d7270531e523b2f81d978c0451f2c0.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F2d297e57571d0afeafb0c30f16793b89.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F54ad568343bd73413aacc0b9e3c639a6.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Faad45840a62ee53567a9cdc1bbf3735b.png\">","To calculate DFT by FFT algorithm, the number of complex multiplication is ( ), and the number of complex addition is ( )","v1",1,{"answer":30,"createTime":5,"id":31,"options":32,"question":37,"source":27,"type":28},[],377544543,[33,34,35,36],"Overlap -add","Overlap -subtract","Overlap -division","Overlap- save","The ways that DFT calculates linear convolution by FFT algorithm are( )",{"answer":39,"createTime":5,"id":40,"options":41,"question":45,"source":27,"type":46},[],377544544,[42,43,44],"Input","Output","Input and output","Generally, the ( ) sequence of decimation-in-time Radix- 2FFT is rearranged in Bit-reversed Order",0,{"answer":48,"createTime":5,"id":49,"options":50,"question":55,"source":27,"type":46},[],377544545,[51,52,53,54],"\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F322609aae59ff4b124f9a2e24de4fa8a.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F7caa53f9529bfd32eee773290c3e0772.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F83574a935c5b1bcbe60b27b763f3b49a.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Ff579dedf31e1db04f6ed87195ca95480.png\">","The number of complex multiplications to calculate the N-point DFT directly is proportional to ( )",{"answer":57,"createTime":5,"id":58,"options":59,"question":64,"source":27,"type":46},[],377544546,[60,61,62,63],"1.05s","1.5s","2.05s","1.0s","Supposed that the time of a complex multiplication is \u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fd67a9145fd7012b845ded8a15362f758.png\">, and assuming that the total time of DFT operation is determined by the time of calculating all multiplications, then the time of calculating a 1024-point DFT directly is ( )",{"answer":66,"createTime":5,"id":67,"options":68,"question":73,"source":27,"type":46},[],377544547,[69,70,71,72],"Spectrum leakage","Time domain aliasing","Spectrum aliasing","Inter-spectrum interference","The length of the sequence \u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fe1f9adf229f6193b63cccc32b46b8cea.png\">is \u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fce04d84526571d74abc3ca1c629d45e9.png\">, sampling points \u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F665c4a1b5ecd5830dcb332751d048734.png\"> in frequency domain, When reconstruct the original sequence using these frequency domain samples \u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Ff04bffd0d50d71de762446d39c0fc823.png\">, which problem will occur ? ( )",{"answer":75,"createTime":5,"id":76,"options":77,"question":82,"source":27,"type":46},[],377544548,[78,79,80,81],"256","256×256","256×255","128×8","How many complex multiplications are needed to calculate 256-point DFT of sequence \u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fe1f9adf229f6193b63cccc32b46b8cea.png\">? ( )",{"answer":84,"createTime":5,"id":85,"options":86,"question":91,"source":27,"type":46},[],377544549,[87,88,89,90],"decimation-in- frequency","decimation-in-time","Both A and B are right","Both A and B are wrong","As shown in figure, the symbol of operation flow graph is butterfly graph of ( ) Radix-2 FFT algorithm.\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F569c2285a7a0ed25708bd59256f0568d.png\">",{"answer":93,"createTime":5,"id":94,"options":95,"question":100,"source":27,"type":46},[],377544550,[96,97,98,99],"1 and 2","1 and 1","2 and 1","2 and 2","Regardless of the particularity of some rotation factors, generally, the number of complex multiplications and complex additions required for a butterfly operation of a Radix-2 FFT algorithm are ( ) respectively",{"answer":102,"createTime":5,"id":6,"options":103,"question":16,"source":27,"type":46},[],[8,9,10,11]]