Change data rates in IEEE® 802.11a WLAN Physical Layer simulink model

Hello all,

Here is the link for 802.11a example provided by matlab

http://nl.mathworks.com/help/releases/R2015b/comm/examples/ieee-802-11a-wlan-physical-layer.html

I want to change data rates and some other parameters so that I can check it for 802.11p. Can anyone help me in changing the data rates from 6, 9, 12, 18, 24, 36, 48, and 54 Mb/s to 3, 4.5, 6, 9, 12, 18, 24 and 27 Mb/s ?

Thank You

Answer 1

[Umeshraja]

Hi @Atreyam Sharma

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!