Computing and Ploting continuous Fourier transform in simulink

How can i compute and plot continuous Fourier transform in simulink without using the fft block? I want to compute the continuous Fourier transform and do some operations on it's spectrum and the compute the inverse Fourier transform after these operations. Operations like filtering, addition and multiplying. Can anyone help?

Answer 1

[Puneet Rana]

You can look at the Spectrum Estimator block in DSP System Toolbox: http://www.mathworks.com/help/dsp/ref/spectrumestimator.html