Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can provide a better downlink bit error rate (BER) performance of direct sequence code division multiple access (DS-CDMA) than the conventional rake combining in a frequency-selective fading channel. FDE requires accurate channel estimation. Recently, we proposed a pilot-assisted channel estimation based...

pendent of the bit estimation algorithm. The constant minimum variance method (CMVM) is used to suppress interference, We estimate DS-CDMA channel described by Rayleigh fading using a Kalman filter. A Kalman filter is proposed for the time varying channel estimation. The proposed scheme is constructed without hit estimation, that is, neither training sequence nor estimated bit symbol is used fo...

Orthogonal frequency-division multiplexing (OFDM) modulation is a promising technique for achieving the high bit rates required for a wireless multimedia service. In this paper we present differentchannel estimation algorithms for OFDM mobile communication systems based on the use of pilot subcarriers. Specifically we present LS (Least Square),MMSE(Minimum Mean Square Error) and LMS iterative c...

In this paper, chip-level adaptive channel estimation has been explored by using LMS algorithm for wideband CDMA channel estimation. The expression for the optimum step-size is modified for fading channel estimation problem. In addition, a new method is proposed to obtain channel estimates with known pilot symbols which is found to give better results than other methods. For slow fading channel...

In this paper, we propose a spectrally efficient frequencydomain channel estimation scheme suitable for training sequence inserted single-carrier (TS-SC) block transmission using frequency-domain equalization (FDE). The proposed scheme performs the channel estimation in two steps and allows the use of shorter TS (but, longer than the channel length) than the conventional channel estimation sche...

The next generation wireless communications require wideband information transmission with high data rates. Orthogonal frequency division multiplexing (OFDM) is recognized as a promising technique which can efficently overcome the multipath effect and inter symbol interference (ISI) of wideband wireless channels [1]. A dynamic estimation of channel is necessary before the demodulation of OFDM s...

In this paper, we study the performance of block diagonalization (BD) scheme for a downlink multiuser multi-input multi-output (MIMO) system with imperfect channel state information (CSI). At each mobile user, information about the channel is obtained by applying the minimum mean-square-error (MMSE) channel estimation method. The channel state information is fed back to the base station through...

ITERATIVE CHANNEL ESTIMATION TECHNIQUES FOR MULTIPLE INPUT MULTIPLE OUTPUT ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEMS Orthogonal frequency division multiplexing (OFDM) is well-known for its efficient high speed transmission and robustness to frequency-selective fading channels. On the other hand, multiple-input multiple-output (MIMO) antenna systems have the ability to increase capacity...

Various types of noise inherent in the channel estimation process for a fading multipath channel are examined and modeled. Performance degradation due to noisy channel estimation in the adaptive matched filter receiver is analyzed, and some numerical results-contrasting reference-directed and decision-directed channel estimation-are presented for the troposcatter channel.

Abstract Channel estimation algorithms have a key role in signal detection in MIMO-OFDM systems. In this system, the number of channel components which need to be estimated is much more than conventional SISO wireless systems. Consequently, the computational process of channel estimation is highly intensive. In addition, the high performance channel estimation algorithms mostly suffer from high...