Based On The Sparse Sparse Decomposition Algorithm Ofdm System Channel Estimation,

With the development of mobile communication technology, therequirements of People for Communication are getting higher and higher.Tohigh-quality, high-speed and multi-business,it requires the development of hightechnology. Orthogonal frequency division multiplexing (OFDM) as a keytechnology in the fourth generation mobile communication technology becauseit has Strong anti-interference, faster data transmission and high bandwidthefficiency.In wireless communications, Transmission is necessary throughvarious paths, that is the channel.In the receiving system,OFDM systemdemodulator need to know the channel information, which must be carried outchannel estimation. The accurate channel estimation is directly related toOFDM system demodulate the correct data rate, that is, the quality ofcommunications, Channel estimation is a key technology in the wireless mobilecommunication. In wireless communications, there is a kind of sparse channel,such as Ultra-fast Wideband channel, the traditional channel is estimated thatmethod did not use sparse channel sparse nature, Sparse channel of theestimated performance is poor,Thereforce study new methods for OFDMsystem of sparse channel estimation is necessary.At First the sparse channel model are established on the basis of theintroduction of wireless channel characteristics, specifically the principle of theOFDM system and the traditional channel estimation methods. Secondly, thesparsity of the sparse channel, in the sparse decomposition algorithm, Iintroduce the principle of the MP and SAMP algorithms and implementationsteps. Compared these two algorithms, Sparsity adaptive matching pursuit(SAMP) algorithm is adaptive to recover the original signal without knowingthe total number of taps, Traditional channel estimation assume that the channeltaps are known, the actual mobile communication sparse path is unknown, thenthe SAMP algorithm is suitable for wireless sparse channel estimation.Finally,based on the merits of the sparse decomposition algorith and the traditional channel estimation method of least squares (LS), a combination of bothproduces a new method for the SAMP-LS algorithm, the new method andseveral other methods are used in the OFDM system of sparse channelestimatemation in the experimental simulation. The simulation results show thatthe sparse decomposition algorithm used for the sparse channel estimatemationis effective, zero-tap of sparse channel is estimated by traditional LS estimated,not only resulting in calculation complexity, but also estimated effect ispoor.Three algorithms are used for OFDM system of sparse channel estimationand simulation results show that the performance of SAMP-LS algorithm in thesparse channel estimation is better than the other two algorithms.