Subcarrier Arrangement in 802.11n/ac 40MHz Channel |

Welcome to my Channel 'Leo's Tech Talk'.
In the 802.11n or 802.11ac wireless communication standard, subcarriers are used in the Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme. OFDM divides the channel into multiple closely spaced orthogonal subcarriers, allowing for efficient data transmission and better handling of multipath interference.
Total Subcarrier allocation for a 40 MHz 802.11n or 802.11ac channel are 128, indexed from -64 t0 63 and constitutes data subcarriers, pilot subcarriers, guard subcarriers and null subcarriers. The subcarrier spacing for a 40MHz 802.11n or 802.11ac channel is 40 MHz/128 = 312.5 kHz.
Subcarrier allocation for a 40 MHz channel:
Total Subcarriers: 128
Data Subcarriers: 108
Pilot Subcarriers: 6
Guard Subcarriers: 11
Null subcarriers: 3