Upsampling and Downsampling
Abstract
Filtering a signal by upsamping in matlab is able to change the original frequency of the signal by a mutiplying it with an integer, and filtering a signal by downsamping in matlab is able to change the original frequency of the signal by a dividing it by an integer. For example, by using the method above, a pure frequency signal with pitch C can be transfer to #C or bC. However, if the signal C needs to be transfer to D or F, then simply mutiplying or dvivding the original frequency by integer is not going to work. Instead, the original frequency needs to be mutiplied by a fraction number. Thus the goal of this project is to design a Matlab function to mutiply the input signal frequency by a fraction to make a small change of the pitch of the input signal.
