A fast algorithm for half-cyclic convolution

The definition of half-cyclic convolution is introduced. It is shown that the computation for cyclic convolution can be carried out based on the half-cyclic convolution, which is more general. The algorithm for half-cyclic convolution then can be used to build an algorithm for cyclic convolution and the fast Fourier transform (FFT), so that some problems in the algorithms for cyclic convolution and the FFT can be solved. An efficient and well-structured algorithm for half-cyclic convolution has been designed, called the Winograd-like algorithm