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给出一个x(t)和h(t)的值:
>> x=[1 -2 3 -4]
x =
1 -2 3 -4
>> h=[2 2 1 3]
h =
2 2 1 3
卷积:
>> y=conv(x,h)
y =
2 -2 3 -1 -11 5 -12
圆周卷积:
通过help cconv我们可以看到圆周卷积相关
help cconv
cconv Modulo-N circular convolution.
C = cconv(A, B, N) circularly convolves vectors A and B. The resulting
vector is length N. If omitted, N defaults to LENGTH(A)+LENGTH(B)-1.
When N = LENGTH(A)+LENGTH(B)-1, the circular convolution is equivalent
to the linear convolution computed by CONV.
% Example #1: Mod-4 circular convolution
a = [2 1 2 1];
b = [1 2 3 4];
c = cconv(a,b,4)
% Example #2: Circular convolution as a fast linear convolution
a = [1 2 -1 1];
b = [1 1 2 1 2 2 1 1];
c = cconv(a,b,11)
cref = conv(a,b)
% Example #3: Circular cross-correlation
a = [1 2 2 1]+1i;
b = [1 3 4 1]-2*1i;
c = cconv(a,conj(fliplr(b)),7)
cref = xcorr(a,b)
举例:
y=cconv(x,h,4)
y =
-9 3 -9 -1
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