| 1. |
What Is Overlap-save Method? |
|
Answer» In this method the data sequence is divided into N point SECTIONS xi(n).Each section contains the last M-1 data points of the PREVIOUS section followed by L new data points to form a data sequence of length N=L+M-1.In CIRCULAR convolution of xi(n) with h(n) the first M-1 points will not AGREE with the linear convolution of xi(n) and h(n) because of aliasing, the remaining points will agree with linear convolution. Hence we discard the first (M-1) points of filtered section xi(n) N h(n). This process is repeated for all sections and the filtered sections are abutted together. In this method the data sequence is divided into N point sections xi(n).Each section contains the last M-1 data points of the previous section followed by L new data points to form a data sequence of length N=L+M-1.In circular convolution of xi(n) with h(n) the first M-1 points will not agree with the linear convolution of xi(n) and h(n) because of aliasing, the remaining points will agree with linear convolution. Hence we discard the first (M-1) points of filtered section xi(n) N h(n). This process is repeated for all sections and the filtered sections are abutted together. |
|