Analysis of OFDM System using Pilot Channel Estimation

Orthogonal Frequency Division Multiplexing (OFDM) is multiplexing technology of orthogonal multicarrier, and the channel estimation model based on pilot in OFDM systems is analyzed; Now that, the channel estimation based on pilot needs interpolation, in order to reduce the complexity of the interpolation algorithm, the FFT channel estimation algorithm based on pilot is studied. Because of the direct FFT channel estimation algorithm existing energy spectrum leakage problems, the optimized FFT channel estimation algorithm based on the Hamming windowed function is put forward. A lot of conventional algorithms have tried to cancel the residual frame synchronization error (RFSE), which causes the performance degradation of channel estimation when using interpolation between pilot subcarriers in comb-type pilot-aided OFDM systems. Orthogonal frequency-division multiplexing (OFDM) is a transmission technique that is based on many orthogonal carriers that are transmitted simultaneously. Channel estimation techniques for OFDM systems, based on combtype pilot arrangement, over frequency-selective Rican and time-varying fading channel are investigated. The advantage of comb-type pilot arrangement, in channel estimation, is the ability to track the variation in the channel, which is the main reason for inter-carrier interference modeled as an additive white Gaussian noise, leading to an increase in the noise level.