Channel Estimation
Yong Soo Cho, Jaekwon Kim, Won Young Yang, Chung G. Kang · 2010
In an OFDM system, the transmitter modulates the message bit sequence into PSK/QAM symbols, performs IFFT on the symbols to convert them into time-domain signals, and sends them out through a (wireless) channel. In general, the channel can be estimated by using a preamble or pilot symbols known to both transmitter and receiver, which employ various interpolation techniques to estimate the channel response of the subcarriers between pilot tones. In general, data signal as well as training signal, or both, can be used for channel estimation. In order to choose the channel estimation technique for the OFDM system under consideration, many different aspects of implementations, including the required performance, computational complexity and time-variation of the channel must be taken into account. This chapter illustrates the channel estimates obtained by using the various types of channel estimation methods with and without DFT technique. Controlled Vocabulary Terms blind equalizers; computational complexity; computer interfaces; discrete Fourier transforms; OFDM