31.0 INTRODUCTIONIn recent times, OFDM has become the multicarrier transmission technique of choice for broadband transmission over wireless channels. It has been adopted for several wireless access technologies, such as IEEE 802.11a/g/n, IEEE 802.16, and Digital Video Broadcasting. OFDM is a promising choice for next generation broadband wireless communication systems because of its ability to combat frequency selective fading and its ease of implementation on cheap hardware that can perform FFT and IFFT calculations. Instead of transmitting digital symbols sequentially over a single wideband channel, OFDM divides the channel into many narrowband subcarriers and then simultaneously transmits digital symbols in parallel over these subcarriers. Each subcarrier then appears to a transmitted digital symbol as a flat-fading channel. In a multiuser scenario, a particular subcarrier at a specific instant may appear differently, in
This is the end of the preview.
access the rest of the document.