Hello, The following example from dsprelated.com shows the design of Sinc filter with the following parameters. The link of the example as below; https://www.dsprelated.com/freebooks/sasp/Example_1_Low_Pass_Filtering.html With the Matlab command fftshift the frequency response of the filter is centered at 0 frequency which is 256 the frequency bin. My question is, how can I move the center of this filter from the frequency bin 256 to the frequency bin 150? % Signal parameters: f = [ 440 880 1000 2000 ]; % frequencies M = 256; % signal length Fs = 5000; % sampling rate Filter parameters: L = 257; % filter length fc = 600; % cutoff frequency % Design the filter using the window method: hsupp = (-(L-1)/2:(L-1)/2); hideal = (2*fc/Fs)*sinc(2*fc*hsupp/Fs); h = hamming(L)' .* hideal; % h is our filter % Choose the next power of 2 greater than L+M-1 Nfft = 2^(ceil(log2(L+M-1))); % or 2^nextpow2(L+M-1) plot(abs(fftshift(fft(h,512)))) Thanks in advance! --------------------------------------- Posted through http://www.DSPRelated.com
Shifting the Sinc filter in the frequency domain
Started by ●February 1, 2018
Reply by ●February 1, 20182018-02-01
On 02/01/2018 09:24 AM, runinrainy wrote:> Hello, > > The following example from dsprelated.com shows the design of Sinc filter > with the following parameters. > > The link of the example as below; > https://www.dsprelated.com/freebooks/sasp/Example_1_Low_Pass_Filtering.html > > With the Matlab command fftshift the frequency response of the filter is > centered at 0 frequency which is 256 the frequency bin. > > My question is, how can I move the center of this filter from the > frequency bin 256 to the frequency bin 150? >Translation in the frequency domain is multiplication by a sine wave (for real, symmetric around DC translation) or by a complex exponential (for complex, look Ma I've got twice as wide a datapath translation). -- Rob Gaddi, Highland Technology -- www.highlandtechnology.com Email address domain is currently out of order. See above to fix.