mosabja
Newbie level 5
I want to know how zero passing OFDM in the center can increase sampling rate. I was going through an implementation of OFDM on National instruments PXI hardware.In it a 64 tone OFDM was taken and then 336 zeros were inserted in between and a 400 point FFT was taken. Then the last 100 complex values were inserted in the beginning of every symbol as cyclic prefix. The result was a 500 complex values . With 336 zeroes,64 data values and 100 cyclix prefix values. then many OFDM symbols were grouped together and transmitted
Then the author of the paper wrote that zeros were inserted so that after sampling at a rate of 100 MS/s at the Arbitrary Waveform generator(baseband to IF conversion) the signal of 16 MHz bandwidth would be generated. Then at the receiver the signal was sampled at a rate of 64 MS/s and then decimated by 4 to get 80 complex values per OFDM symbol,64 of data and 16 of cyclic prefix. I dont understand how the signal would carry 16 MHz bandwidth and how the reception and then decimation would yield 80 complex values with 64 data values and 16 cyclic prefix length.
Then the author of the paper wrote that zeros were inserted so that after sampling at a rate of 100 MS/s at the Arbitrary Waveform generator(baseband to IF conversion) the signal of 16 MHz bandwidth would be generated. Then at the receiver the signal was sampled at a rate of 64 MS/s and then decimated by 4 to get 80 complex values per OFDM symbol,64 of data and 16 of cyclic prefix. I dont understand how the signal would carry 16 MHz bandwidth and how the reception and then decimation would yield 80 complex values with 64 data values and 16 cyclic prefix length.
