The generalized overlap-add and overlap-save methods using discrete sine and cosine transforms for FIR filtering

We investigate the generalized overlapped and overlap-save methods (GenOLA and GenOLS) using discrete sine and cosine transforms (DSTs and DCTs). Compared to the GenOLA and CenOLS using discrete Fourier Transform (DFT), the merit of the DST and DCT approach is that the filtering can be implemented by real-valued operations. It is shown that the computational complexity can be minimized when the transform size of the DST or DCT is chosen optimally, and a good tradeoff between the computational complexity and system delay can be achieved.