DESIGNING A FIR FILTER:
Following are the steps to design linear phase FIR filters Using Windowing Method.

I. Clearly specify the filter specifications.
Eg: Order = 30;
Sampling Rate = 8000 samples/sec
Cut off Freq. = 400 Hz.

II. Compute the cut-off frequency Wc
Eg: Wc = 2*pie* fc / Fs
= 2*pie* 400/8000
= 0.1*pie

III. Compute the desired Impulse Response h d (n) using particular Window
Eg: b_rect1=fir1 (order, Wc , 'high',boxcar(31));

IV. Convolve input sequence with truncated Impulse Response x (n)*h (n)