Blind adaptive channel estimation in ofdm systems

Abstract

Abstract:We consider the problem of blind channel estimation in zero padding OFDM systems. For the first time, blind adaptive algorithms are proposed that identify the impulse response of the multipath channel. In particular, we develop RLS and LMS schemes that exhibit rapid convergence combined with low computational complexity and numerical stability. Both versions are obtained by properly modifying the orthogonal iteration method used in Numerical Analysis for the computation of singular vectors. With a number of simulation experiments we demonstrate the satisfactory performance of our adaptive schemes under diverse signaling conditions. Key

BER Analysis of OFDM Receiver Using MMSE Channel Estimation Method with PTS for Different Subblocks

“…The received signal at known pilot locations are then interpolated for estimating the complete channel. Blind channel estimation techniques [15] do not use pilots in order to achieve high spectral efficiency. Non-blind techniques are implemented with high computational complexity and require large amount of data to evaluate the statistics of the channel.…”

“…In OFDM system, the orthogonal property of the subcarriers allows that each subcarrier to be identified as an independent channel. So the received signal is the product of the transmitted signal and frequency response of the channel [15]. The linear MMSE channel estimation algorithm is used to evaluate the BER performance of PAPR reduced OFDM signal using comb-type pilot arrangement.…”

“…The performance measure employed in frequency domain channel estimates is Mean square error (MSE) and it is defined by 2 ( ) ( ) MSE E H k H k    (15) BER performance measure is also used to evaluate the performance of the receiver using MMSE channel estimation method.…”

Blind and semi-blind channel estimation with fast convergence for MIMO-OFDM systems

“…Rossi et al presented the linear MMSE estimation of time-frequency variant channels for MIMO-OFDM systems via the use of two serially concatenated one-dimensional Slepian-basis expansions [24]. Based on the orthogonal iteration techniques, Doukopoulos and Moustakides proposed the blind adaptive subspace channel estimation for the ZP-OFDM systems [25]. We will evaluate the proposed methods using the adaptive channel estimation algorithm [25] in the computer simulations.…”

Frame synchronization, channel estimation scheme and signal compensation using regression method in OFDM systems

“…Both blind channel estimation scheme and data-aided channel estimation scheme are proposed. Blind channel estimation techniques try to estimate the channel information without any knowledge of the transmitted signal [10]. With the data-aided schemes, pilots or training sequences are inserted in the transmitted signal to estimate the channel response [11][12][13][14][15].…”