ieee802.11
Table of Contents
Standards for WiFi communication.
The a
standard dictates using orthogonal frequency division
multiplexing along with quadrature phase shift keying for data and binary phase
shift keying for headers.
- Bandwidth
- 20MHz
- Occupied bandwidth
- 16.6MHz
- Subcarrier spacing
- 312KHz (20MHz/64)
- FFT Size
- 64
- Total subcarriers
- 52 (-26: 26)
- Data subcarriers
- 48
- Pilot subcarriers
- 4 (-21, -7, 7, 21)
- DC subcarrier (0)
- null
1. Frame structure
- Preamble
The preamble consists of data meant to be used for a timing and synch. algorithm like schmidl and cox.
- 10 short training symbols
- used for AGC, timing synchronization and coarse frequency offset.
- 2 long symbols
- equal magnitude on all 52 carriers. Used for channel equalization and fine frequency offset.
- Data
Pilots transmitted on BPSK, data on QPSK.