10.5. Orthogonal Frequency Division Multiplexing
A 64-point complex number IFFT/FFT operation forms the modulation mechanism for this 802.11a wireless Ethernet. Among 64 subcarriers, 48 of them are used for BPSK, QPSK, 16) Quadrature Amplitude Modulation (QAM), or 64QAM, 4 of them are used for pilot tone. Complex time domain signals are modulated onto in-phase and quadrature channels of an RF carrier separately. A rate 1/2 convolution code is used for error protection. Rate 2/3 and 3/4 codes are derived through puncturing. An interleaving process is used to randomize subcarrier and bit location distribution among each OFDM symbol.
10.5.1. Summary of 802.11a Standards
The packet format for the OFDM implementation of wireless Ethernet at 5 GHz ...
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