In this paper, we derive a closed-form bit error rate (BER) solution for equaland nonequal-strength L-path channels considering imperfect channel estimation. The channel model assumes independent paths with Rayleigh fading statistics in a single-cell downlink environment. By using a simple maximum likelihood (ML) estimator, the effects of the channel estimation error due to Doppler shift, resid...

Iterative multi-user detection and time-variant channel estimation in a multi-carrier (MC) code division multiple access (CDMA) uplink requires high computational complexity. This is mainly due to the linear minimum mean square error (MMSE) filters for data detection and time-variant channel estimation. We develop an algorithm based on the Krylov subspace method to solve a linear system with lo...

This paper presents an empirical mode decomposition (EMD) based adaptive filter (AF) for channel estimation in OFDM system.  In this method, length of channel impulse response (CIR) is first approximated using Akaike information criterion (AIC). Then, CIR is estimated using adaptive filter with EMD decomposed IMF of the received OFDM symbol. The correlation and kurtosis measures are used to sel...

In this thesis, channel estimation techniques are studied and investigated for a novel multicarrier modulation scheme, Universal Filtered Multi-Carrier (UFMC). UFMC (a.k.a. UFOFDM) is considered as a candidate for the 5th Generation of wireless communication systems, which aims at replacing OFDM and enhances system robustness and performance in relaxed synchronization condition e.g. time-freque...

Time division duplex multi-carrier code-division multiple-access (TDD/MC-CDMA) exploits the strong correlation between upand downlink channel conditions of the slowly timevarying channels. The TDD mode enables pre-compensation of the channel influence on the uplink signal already at the mobile station based on the channel estimation from the downlink signal. The aim of this paper is to carry ou...

Channel Estimation is a major problem encountered by receiver designers for wireless communications systems. The fading channels encountered by the system are usually time variant for a mobile receiver. Besides, the frequency response of the channel is frequency selective for urban environments where the delay spread is quite large compared to the symbol duration. Estimating the channel is esse...

Linear minimum mean square error (LMMSE) receivers are capable of suppressing multiple access interference and near-far occurrences in a code division multiple access (CDMA) system operating in multipath fading wireless channels. Their relative low complexity makes them suitable for both uplink and downlink receivers. Third generation receivers are mainly based on coherent detection. Carrier fr...

The effect of two different pilot-assisted channel estimation techniques on BER in Multi-Carrier CDMA (MCCDMA) is considered. The first technique involves sending both data and pilot symbols in the same OFDM symbol. The second technique involves sending data and pilot symbols in separate OFDM symbols. In both cases multi-access interference is present. Simulations of both systems in a UMTS mult...

In this paper, we address the problem of carrier frequency offset (CFO) estimation for multipleinput multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. We reconstruct the received signal to form data model with multi-invariance property, and then multiinvariance MUSIC algorithm for CFO estimation is proposed. Our proposed algorithm has the better CFO estimation pe...