- Bit rate $ R_b = 25.6 [Mbit/s]$
- Sampling frequency at the input of the receiver: $ f_p = 8 [MHz]$
- Protective spacing between successive OFDM symbols: $ τ = 16 [µs] $
- The combined length of the OFDM symbol and the prefix: $ T_s = 80 [µs]$
1. The number of signal samples per cyclic prefix
So here is the problem because I don't know how can I calculate this number of samples. I can calculate the number of data bits by this formula:
$R_b = B/T $ where T is the total transmission time ($80 [µs]$).
But I want samples, so maybe I should use the time of the cyclic prefix that is $ 16 [µs] $, but what next?
2. The size of the constellation (number of points) on a given sub-channel (assumption: in each sub-channel the same constellation and all sub-channels transmit data)
So I know this equation:
$T_s = N*T_p$
$T_p = 0.000000125 $
But N here equals 640, so 640 = $2^k$, isn't there something wrong?
3. Size N of FFT / IFFT transformation
Isn't this that 640 I have counted above?
4. Provide the effective value of data transmission speed $R_b$ if 64 subchannels in each OFDM symbol are used for transmitting pilots
I don't know how to do this one
5. The number of information bits transmitted in each single OFDM symbol
Should I use this formula (thanks MarcusMuller!)?:
But there is another problem with k (because of 640 = $2^k$)...
Any suggestions? I will be grateful for any help!