已知信号的频谱[tex=2.643x1.357]xVGH50na8B3EKfptmWXbwg==[/tex]如题4-14所示，试求信号[tex=2.286x1.286]I9vHB/dIxHr1f2z1yh63GA==[/tex]。[img=275x156]17d4ffe9a1ad6a2.png[/img]

2022-06-12

已知信号的频谱[tex=2.643x1.357]xVGH50na8B3EKfptmWXbwg==[/tex]如题4-14所示，试求信号[tex=2.286x1.286]I9vHB/dIxHr1f2z1yh63GA==[/tex]。[img=275x156]17d4ffe9a1ad6a2.png[/img]

答案：

将频谱分解成两个矩形波之和[tex=8.714x1.357]EhSybivVkBwPp5n+KhEUQ2alJApcSLDIySUPuXA8ZXd/cgy98UU5TsLkCsLm9IUP[/tex]由于[tex=10.214x2.286]o58cctZNhTyORSZqRPbmJ/rhk9FPTXeAcLd1Bj0nWx8pLK7PI+YVA5iBy6xY6dDezz8LGoY1HylBkJXK7JXRVpr1IHcnJlBjVOQHXjZ7xMCYAa5oo+rNsTz68aW27RrHHYvqTx5caJ2B2ocCBUSc9ac7F5KlXL5VTv6/+7dsFEA=[/tex]所以 [tex=10.643x2.357]MZj3g5XhaIwqbfLjoLNLlY8tVoCl6BvGX7vpsvqZmvcmZuhCVkz4nWpaJoGSN5KWH1f/Z8zwOEjhHbbzPRBjhg==[/tex]

举一反三

内容

0
以4，9，1为为插值节点，求\(\sqrt x \)的lagrange的插值多项式 A: \( {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) + {1 \over {24}}(x - 4)(x - 9)\) B: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) + {1 \over {24}}(x - 4)(x - 9)\) C: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x +1) + {1 \over {24}}(x - 4)(x - 9)\) D: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) - {1 \over {24}}(x - 4)(x - 9)\)
1
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2
某复信号 [tex=1.714x1.357]AphGGQbUXHAeuIs1fgWQNA==[/tex]的频谱如题 4-32 图所示, 试画出以抽样角频率 [tex=3.0x1.0]pBuMIh+924YD+f+YdiwlC5D3YRRSSMJNXaCgCE1DDtE=[/tex] 抽样后信号的频谱。[img=267x253]17d5f410e16b0ba.png[/img]
3
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4
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