---In this paper we present an improved and robustchannel estimation algorithm for OFDM mobile communication systems based on the use of pilot subcarriers.Specifically we present an iterative channel estimation technique to improve the performance of channel estimators.In iterative receiver structures,soft information becomes available after the decoding stage.This information is used to enhanc...

In this paper to improve the channel estimation accuracy in OFDM system , channel state information is required for signal detection at receiver and its accuracy affects the overall performance of system and it is essential to improve the channel estimation for more reliable communications. This paper addresses channel estimation based on time-domain channel statistics, using a general model LS...

Channel estimation is necessary for coherent detection in orthogonal frequency division multiplexing (OFDM) receivers. For accurate estimation, known pilot symbols are sent with data symbols at the transmitter. In general, these pilot symbols are placed with a regular pattern in two-dimensional (2-D) time-frequency grid. In a static additive Gaussian noisy channel, the channel estimation perfor...

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

In this paper, three approaches for channel estimation method are proposed and analyzed for third generation (3G) Wideband Code Division Multiple Access (W-CDMA) communication systems. The down link (DL) channel estimation schemes researched are to use time multiplexed pilot data symbols, code multiplexed common pilot channel (CPICH) , and to combine the channel estimate results )om these two a...

The channel estimation techniques for OFDM systems based on pilot arrangement are investigated. The channel estimation based on comb type pilot arrangement is studied through different algorithms for both estimating channel at pilot frequencies and interpolating the channel. The estimation of channel at pilot frequencies is based on LS and LMS while the channel interpolation is done using linea...

Accurate alignment and vertical channel instability play an important role in the strap-down inertial navigation system (SINS), especially in the case that precise navigation has to be achieved over long periods of time. Due to poor initialization as well as the cumulative errors of low-cost inertial measurement units (IMUs), initial alignment is not sufficient to achieve required navigation ac...

The principle objective of this work is to enhance the knowledge about channel estimation and to compare the existing channel estimation techniques under different channel conditions. Normally the received signal is corrupted by the channel (Multipath, ISI). The estimation of a time-varying multipath fading channel is a difficult task for the receiver. Its performance can be improved if an appr...

This paper is concerned with the estimation of state trajectory of linear discrete time dynamic systems subject to parametric uncertainty over the compound erasure channel that uses feedback channel intermittently. For this combined system and channel, using the data processing inequality and a robust version of the Shannon lower bound, a necessary condition on channel capacity for estimation o...