g*****d
发帖数: 210 | 1 Hi all,
Lst say a input signal IP with 0~200KHz bw is sampled at fs=16MHz (lets call
it X), then pass through a 1st order CIC decimation filter (R=8, M=1) to
get 2MHz output (lets call it Y).
Let define Δf as shifting the signal to center at f, so
X = IPΔ0 + IPΔ16M + IPΔ32M ...
and sinc is the sinc function without alias
1. What does the Y spectrum now look like ???
Should it be (X* sincΔ0)Δ0 + (X* sincΔ0)Δ2M +(X* sincΔ0)Δ4M ...
or X* sincΔ0 + X* sincΔ2M + X* sincΔ4M ...
2. How | E****d
发帖数: 146 | 2 for question 1, the answer should be the second choice, I think. |
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