如何找到组成离散信号的每个余弦项的系数？

Question

I have a discrete sequence of N real values. Is there a way to find a list of N-1 real numbers x[n] so that this:

with the nth coefficient is x[n], and each element in my original list is y[k], with k representing the index of the element in the list, starting from k=0, is true?

Answer 1

我相信你正在寻找一个离散余弦变换III型，如图所示这里或其倒数。