Overlap Add Method(OAM) & Overlap Save Method(OSM)
When the input sequence is too large, the Convolution of the entire signal at a time is time consuming and tedious. So we break the input sequence.It is an efficient way to evaluate the discrete convolution of a very long signal x [ n ].
When an input signal x[n] is given to a Digital FIR filter the methods used to get the output sequence are-OAM and OSM.
The practical implementation of these methods in done in the Lab session. OAM method involves decomposing the input signal and performing linear convolution on each of them individually. The decomposed outputs are then combined together.Similarly OSM method involves decomposing of input.But this method deals with adding some previous values to each decomposed input and then performing circular convolution.
The decomposed outputs are then combined by removing the first few values from each of them to get the result. This procedure is designed into a code and executed to get the output sequence on the computer when user defined input sequence is typed in Lab session.
The delay decreases as the output doesn't require the whole input data sequence at a single instant.
ReplyDeleteThis is a method used for Digital FIR filter
ReplyDeleteCannot be used for IIR filter as input is infinite.
DeleteUsed for longed input sequence.
ReplyDeletedelay is reduced in these methods
ReplyDeleteIt is used for real time signals with very long signal lengths
ReplyDelete