To modify the data rates from 802.11a to 802.11p standards, we need to understand how data rates are calculated in these protocols. The maximum physical data rate is determined by the following formula:
Data Rate = 
Where
: Number of Data Subcarriers (depends on Channel Bandwidth)
: Number of coded bits per OFDM symbol (For 64 QAM,=6 )- R: Coding Rate: 1/2, 2/3, 3/4, 5/6
: OFDM symbol Duration including Guard Time
The key difference between 802.11a and 802.11p lies in the OFDM symbol duration. In 802.11p, the symbol length is doubled to 8μs (compared to 802.11a's 4μs). This change has several implications:
- The subcarrier spacing (scs) is halved (due to inverse proportionality with symbol length)
- The sampling rate is halved because it's determined by the product of FFT length and subcarrier spacing (scs)
For a comparison of parameters between these standards, I recommend referring to Table 4 in:
Arena, F.; Pau, G.; Severino, A. A Review on IEEE 802.11p for Intelligent Transportation Systems. J. Sens. Actuator Netw. 2020, 9, 22. https://doi.org/10.3390/jsan9020022
Hope this helps!
