CogWave BlindOFDMA is an orthogonal frequency division multiplexing
(OFDM)-based waveform with a spectrum sensing block based on energy
detection to determine the best sub-channel for transmission. Multiple
users are handled by orthogonal frequency division multiple access
(OFDMA) and full-duplex is enabled either by time division duplexing
(TDD) or frequency division duplexing (FDD). A complete OFDM blind
receiver which does not require the use of pilot symbols is used for
time, frequency, and phase offset estimation as well as channel
estimation. Based on channel and noise estimation, adaptive modulation
is used to improve the link throughput. Cyclic redundancy check (CRC)
and forward error correction (FEC) are used to detect and correct errors
within a frame's preamble and postamble.