This paper introduces a new Channel Estimation (CE) filter called Polyphase Lowpass-Interpolation (PLI)-filter for downlink coherent Rake-combining in a DSCDMA mobile environment. In this case some UTRA FDD scenarios are taken for showing the feasibility of this approach. It uses known periodically time-multiplexed pilot symbols for interpolating the channel coefficients in between. The idea of...

Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can increase the downlink bit error rate (BER) performance of DS-CDMA beyond that possible with conventional rake combining in a frequency-selective fading channel. FDE requires accurate channel estimation. Recently, we proposed a pilot-assisted channel estimation (CE) based on the MMSE criterion. Using ...

Two kinds of RAKE receiver combining schemes are investigated for a partial parallel interference cancellation (PPIC) technique, including maximal ratio combining (MRC) and minimum mean-squared error (MMSE) combining, in directsequence code-division multiple access (DS-CDMA) ultrawideband (UWB) systems. We use the normalized least meansquared algorithm to approach the MMSE solution for the RAKE...

Overlap frequency-domain equalization (FDE) requires no guard interval (GI) insertion while achieving the frequency diversity gain and hence can be applied to the present cellular systems using direct sequence-code division multiple access (DS-CDMA). It has been confirmed that assuming the ideal channel estimation, overlap FDE can provide almost the same bit error rate (BER) performance as the ...

Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can replace the conventional rake combining while offering significantly improved bit error rate (BER) performance for the downlink DS-CDMA in a frequency-selective fading channel. However, the presence of residual inter-chip-inference (ICI) after FDE produces orthogonality distortion among the spreading...

Karl-Dirk KAMMEYER and Dirk NIKOLAI Univ. of Bremen, Dept. of Telecommunications1 , P.O. Box 33 04 40, D-28334 Bremen, Germany Tel.: ++(49)-421/218-2453, Fax: ++(49)-421/218-3341, E-mail: [email protected] Abstract2: In this paper, we present a novel transmission scheme with application to Direct Sequence Code Division Multiple Access (DSCDMA) combining M -ary orthogonal and PSK modula...

A well-known receiver strategy for direct-sequence code-division multiple-access (DS-CDMA) transmission is iterative soft decision interference cancellation. For calculation of soft estimates used for cancellation, the distribution of residual interference is commonly assumed to be Gaussian. In this paper, we analyze matched filter-based iterative soft decision interference cancellation (MF ISD...

Abstract— The bit error rate (BER) performance of DSCDMA in a frequency-selective fading channel can be significantly improved by the use of frequency-domain equalization (FDE). However, for a small spreading factor SF, the residual inter-chip-inference (ICI) degrades the BER performance. In this paper, we propose an iterative frequency-domain ICI cancellation (FD-ICIC) scheme for DS-CDMA. In t...

A Stochastic Conjugate Gradient Algorithms (SCGA) is proposed for the solving nonlinear optimization problem assodated with the multi-nser constant modulus algorithm (CC-CMA) for DSCDMA receivers in a multi-user environment. The algorithm referred to as the stochastic conjngate gradient CC-CMA (SCGCC-CMA). Simulatious show that the SCGCCCMA algorithm preserves the fast convergence rate of the b...

Currently, a global third generation cellular system based on CDMA is being developed with a wider bandwidth than existing second generation system. The RAKE Receiver instead of completely eliminating multipath uses techniques to effectively utilize multipath to produce the desired signal. This paper proposes interference mitigation by CDMA RAKE receiver with WalshHadamard Sequence for DSCDMA s...