Aug 26, 2013 #1 M mr_byte31 Full Member level 5 Joined Oct 19, 2005 Messages 295 Helped 10 Reputation 20 Reaction score 8 Trophy points 1,298 Activity points 3,241 Hi All, I was trying to make some simple calculations on LTE **broken link removed** lets take 1.4MHz as an example 1.4MHz cell uses FFT with size 128, we all know that the spacing between subcarriers are 15KHz so if we want to calculate the BW from FFT ----> (128-1)*15K = 1.905 MHz which is much bigger than 1.4Mhz i got confused now! any help ?
Hi All, I was trying to make some simple calculations on LTE **broken link removed** lets take 1.4MHz as an example 1.4MHz cell uses FFT with size 128, we all know that the spacing between subcarriers are 15KHz so if we want to calculate the BW from FFT ----> (128-1)*15K = 1.905 MHz which is much bigger than 1.4Mhz i got confused now! any help ?
Aug 26, 2013 #2 FvM Super Moderator Staff member Joined Jan 22, 2008 Messages 53,710 Helped 14,812 Reputation 29,921 Reaction score 14,445 Trophy points 1,393 Location Bochum, Germany Activity points 303,649 Consider the simple fact that FFT size must be a power of two. Part of the result might be discarded.
Consider the simple fact that FFT size must be a power of two. Part of the result might be discarded.
Aug 27, 2013 #3 M mr_byte31 Full Member level 5 Joined Oct 19, 2005 Messages 295 Helped 10 Reputation 20 Reaction score 8 Trophy points 1,298 Activity points 3,241 i know that FFT should be power of 2 , 128 = 2^7 (128-1) = number of spacings between FFT points so lets return back to the calculations , (128-1)*15K = 1.905 MHz is larger than 1.4MHz, do i have probs in my calculations?
i know that FFT should be power of 2 , 128 = 2^7 (128-1) = number of spacings between FFT points so lets return back to the calculations , (128-1)*15K = 1.905 MHz is larger than 1.4MHz, do i have probs in my calculations?