Low-density parity check (LDPC) codes of small, realizable size and regular form are analyzed in different multipath fading conditions. The multipath fading conditions vary from uncorrelated channels (with and without channel state information (CSI)) to a correlated land mobile channel at a frequency of 900 MHz. The effects of an external channel interleaver and varying mobile speed in a correl...

With equipping multiple antennas at both transmitter and receiver ends, the signals in the wireless OFDM systems could be transmitted over multipath fading channels for achieving benefits and high flexibility. In this paper, we focus on MIMO-OFDM systems that simultaneously perform channel estimation in order to combat additive noise, and multipath fading. The performance improvement is confirm...

In recent years, there has been considerable interest in the use of CDMA in mobile communications. Bit error rate is one of the most important parameters in the evaluation of CDMA systems. In this paper, we develop a technique to find an accurate approximation to the probability of bit error for asynchronous direct–sequence code division multiple–access (DS/CDMA) systems by modeling the multipl...

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 project studies and identifies the PSK-based digital modulation scheme (BPSK, QPSK or GMSK) that gives the best BER performance in a multipath fading environment using computer simulation (MATLAB). Each PSK-based digital modulation are modeled and simulated under different channel conditions. Subsequently, a comparison study is carried out to obtain the BER performance for each PSK-based t...

It is of great interest to provide high data rate services in wireless communication systems. In order to support such services, it is desirable to extend space-time (ST) coding, originally proposed for known, frequency-nonselective fading channels, to unknown, multipath channels. In this paper, we consider the problem of interference suppression for wireless TDMA (time division multiple access...

OFDM has been proven to be a viable technique to overcome multipath fading in wireless channels. While OFDM systems convert a multipath fading channel into a series of equivalent flat fading channels they lack the inherent diversity available in multipath channels. Theoretically an uncoded OFDM system needs a simple receiver due to ISI free channel, but their performance deteriorates in the pre...

OFDM has been proven to be a viable technique to overcome multipath fading in wireless channels. While OFDM systems convert a multipath fading channel into a series of equivalent flat fading channels they lack the inherent diversity available in multipath channels. Theoretically an uncoded OFDM system needs a simple receiver due to ISI free channel, but their performance deteriorates in the pre...

Blind adaptive equalization with application for Non-Linearly Amplified (NLA) quadrature amplitude modulation (QAM) systems in multipath selective fading channels is presented. With an offset sampling strategy in the receiver, the proposed blind equalization using Constant Modulus Algorithm (CMA) exhibits a fast convergent speed for a family of quadrature modulated systems in NLA and multipath ...

We explore in this paper code division multiple access systems with multiple transmitter and receiver antennae combined with algebraic constellations over a quasi-static multipath fading channel. We first propose a technique to obtain transmit diversity for a single user over quasi-static fading channels by combining algebraic constellations with full spatial diversity and spreading sequences w...