signal decimation

makris

Can anybody tell a few good sources for 1dimentional signal decimation? Either books or URLs?

I know how to use the "decimate" function in matlab thus perform decimation, but my goal is to code a function in matlab (or C) to perform the same process. That is why I need the theory behind decimation.

Thanks

ravi_bm_87

i don't know your application but in decimation filtering and down sampling is perform in a paralle way . suppose if we down sample first and then we will filter with low pass filter we have to face alising while if we do filtering first then down sample then also it its useless as we have to spend a lots of memory to store the FIR data so what we do is every time when we delay signal by one sample,we down sample it and multiply it with FIR coeeficient in this way we acchieve both the things

y(n)=[N-1]\sum[i=1]h(i)*X(Mn-i);

i know its a bit confussing but try to google