In this paper, the effects of multipath fading and shadowing over the propagation channel are observed through the performance analysis of switch and stay selection combining (SSC) technique. The short term fading (multipath fading) in conjunction with the long term fading (shadowing) are both modeled by Generalized-K (KG) distribution. The proposed system is considered as interference-limited ...

Suppression of multiuser interference (MUI) and mitigation of multipath effects constitute major challenges in the design of thirdgeneration wireless mobile systems. Most wideband and multicarrier uplink CDMA schemes suppress MUI statistically in the presence of unknown multipath. For fading resistance, they all rely on transmitor receivediversity and multichannel equalization based on bandwidt...

We compare single user digital multi-carrier spread spectrum (MC-SS) modulation with direct sequence (DS) SS (with a modified implementation) in the presence of narrowband interference (NBI) and multipath fading. We derive closed-form expressions for the symbol error probability for both the linear MMSE receiver as well as the conventional matched-filter receiver under different scenarios: addi...

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.

Iterative algorithms are an attractive approach to approximating optimal, but high-complexity, joint channel estimation and decoding receivers for communication systems. We present a unified approach based on factor graphs for deriving iterative message-passing receiver algorithms for channel estimation and decoding. For many common channels, it is easy to find simple graphical models that lead...

A blind joint estimator for multipath diversity and PN code timing error is proposed in this paper for direct-sequence spread-spectrum signaling on a frequency-selective fading channel. In the multipath diversity combiner, a modi ed known modulus adaptive (KMA) algorithm is used to cope with time-varyingmultipath e ects and to perform multipath diversity combining in the blind mode. In the code...

| Diversity techniques provide a powerful approach to combat fading. Due to the presence of multipath and Doppler shifts, the mobile wireless channel inherently provides diversity that can be exploited using appropriate signaling and reception. While existing CDMA systems exploit only multipath diversity using spread-spectrum signaling, we develop signaling and reception schemes that exploit jo...

This paper investigates the prediction of single input single output (SISO) narrowband multipath fading channels for mobile-to-mobile wireless communications. Using a statistical model for mobile to mobile urban and suburban channels, we derive a parametrized model and utilize the ESPRIT algorithm to extract the effective Doppler frequencies from noisy channel estimates. The parameter estimates...

A Generalized Frequency Hopping (GFH) OFDMA system is developed in this paper as a structured long code DS-CDMA system in order to bridge frequency hopped multi-carrier transmissions with long code DS-CDMA. Through judicious code design, multiuser interference is eliminated deterministically in the presence of unknown frequency-selective multipath channels. Thanks to frequency hopping, no singl...