Research On Channel Estimation Algorithms For OFDM System

Along with development and improvement of society, many researchers pay much attention to developing system of wireless broadband digital communication. In wireless broadband digital communication, Inter-Symbol Interference (ISI) caused by time disperse of radio channel is one of main factors that limit bandwidth of communicated information and system performance of communication. In receiver, Orthogonal Frequency Division Multiplexing (OFDM) system can easily cancel ISI and equalize frequency-selective fading that are both caused by time disperse of radio channel .For this, the research aiming to apply OFDM to system of wireless broadband digital communication had received more and more attention in recent years. In system of wireless broadband digital communication based on OFDM ,receiver must acquire Channel Status Information(CSI) to equalize frequency-selective fading and implement decoding of Space-Time Code(STC). This paper , we summarized multipath and time-varing statistic properties of wireless channel . Based on the these analysis , we investigated the channel estimation methods in block-type and comb-type pilotsarrangements .Furthermore we proposed a new DCT-based channel estimation method for OFDM systems and simulated by computer. Results shows that the proposed algorithms have simpler, better performance and wider application than traditional algorithms.