This paper investigates pilot based channel estimation techniques for short code DS-CDMA in a multipath environment. It will be shown that the conventional correlative estimation algorithm is biased and very sensitive to multi-user interference (MUI). Therefore, we suggest two advanced estimation algorithms. The first one eliminates the inherent path cross talk and yields an unbiased estimate w...

In this paper two different channel estimation techniques for a mobile beyond 3G MC-CDMA systems are evaluated. These techniques are the robust MMSE estimation with pre-estimator of autocorrelation channel matrix and the delay profile based estimation. Simulation results, carried out over a realistic propagation channel, compare the proposed channel estimation algorithms, in terms of the mean s...

This paper proposes a new blind adaptive MLSE equalizer for frequency selective mobile radio channels. The proposed equalizer performs channel estimation for each survivor path of the Viterbi algorithm (VA), and restricts the number of symbol candidates for the channel estimation in order to reduce prohibitive complexity. In such channel estimation, autocorrelation matrices of the symbol candid...

Least mean square (LMS) based adaptive algorithms have been attracted much attention since their low computational complexity and robust recovery capability. To exploit the channel sparsity, LMS-based adaptive sparse channel estimation methods, e.g., L1-norm LMS or zero-attracting LMS (sparse LMS or ZA-LMS), reweighted zero attracting LMS (RZA-LMS) and Lp-norm LMS (LP-LMS), have been proposed b...

Multiple transmit-and-receive antennas can be used in orthogonal frequency division multiplexing (OFDM) systems to improve communication quality and capacity. In this paper, we present two techniques to improve the performance and reduce the complexity of channel parameter estimation: optimum training-sequence design and simplified channel estimation. The optimal training sequences not only sim...

In this paper, various channel estimation techniques for iterative receivers are compared for OFDMIDMA system. Pilot –assisted based, semi-blind estimation, blind estimation and Decision –directed channel estimations techniques are considered and there comparisons are presented. The considered estimation techniques differ in terms of complexity, as well as performance. The main contribution of ...

In the next generation mobile communication systems, multiple-input multiple-output (MIMO) multiplexing is a technique indispensable to achieve very high-speed data transmission with a limited bandwidth. In MIMO multiplexing, it is necessary to estimate all channel gains between transmit and receive antennas for signal detection at the receiver. In this paper, we propose minimum mean square err...

A robust sparse least-mean mixture-norm (LMMN) algorithm is proposed, and its performance is appraised in the context of estimating a broadband multi-path wireless channel. The proposed algorithm is implemented via integrating a correntropy-induced metric (CIM) penalty into the conventional LMMN algorithm to modify the basic cost function, which is denoted as the CIM-based LMMN (CIM-LMMN) algor...

A multiple-input multiple-output (MIMO) communication system combined with the orthogonal frequency division multiplexing (OFDM) modulation technique can achieve reliable high data rate transmission over a broadband wireless channel. A main challenge in wireless communication is retrieval of the channel state information and ICI cancellation. The channel estimation and ICI cancellation is estim...