This paper presents the results obtained by two linear multiuser detectors, namely the decorrelating detector and the minimum mean square error (MMSE) one, when the channel is affected by the flat Rayleigh fading and gray images are transmitted through the system. All the users transmit their information with the same power, but the spreading codes are correlated one another. We will investigat...

In this paper, we theoretically study the bit error rate (BER) performance of OFDM systems with MDPSK modulation for subchannels in frequencyselective flat Rician fading and additive white Gaussian noise (AWGN). Both the Rayleigh and Rician fading conditions are considered. The differential detection technique is used to avoid the need of a complex equalization process. Circular prefixes are ad...

The robustness of different interactive schemes for demodulating M-ary orthogonal signaling formats in asynchronous DS-CDMA systems to the synchronization errors is addressed in this paper. The system under study resembles the uplink of an IS-95 system. The channel is assumed to be a time-varing flat Rayleigh-fading channel. Our simulation results show that performance degradation for the consi...

Simple closed-form solutions for the average error rate of several coherent modulation schemes including square M-QAM, DBPSK and QPSK operating over slow flat Rician fading channel are derived. Starting from a novel unified expression of conditional error probability the error rates are analysed using PDF based approach. The derived end expressions composed of infinite series summations of Gaus...

In this work we analyze the evolution of the multiuser-efficiency for the uplink of a coded iterative CDMA receiver with channel estimation in flat Rayleigh fading channels with block fading characteristic. The receiver processing parts are: Multiuser detector implemented as PIC-LMMSE, a bank of single user MAP decoders, and a channel estimator unit which makes use of fed back soft bit values i...

A tutorial study is performed on the capacity of multiple antenna wireless communication systems. Multiple antenna structures can be classified into single-input multiple-outputs (SIMO), multiple-inputs singleoutput (MISO), and multiple-inputs multiple-outputs (MIMO) systems. Assuming that the channel is known at receiver, capacity expressions are provided for each structure, under the conditio...

The objective of this paper is to analyze slow, flat, Rayleigh fading channels in modern digital communication systems having different coherent modulation techniques. Most of the packages can only be used to analyze analog communication systems, but modern systems are, increasingly, digital. Improved many-on-many (IMOM) is a two-dimensional, graphical-oriented, radio frequency modeling tool is...

In this paper we investigate the impact of different equalization techniques for digital communication systems that employ MPSK and MQAM modulation technique to transmit information such as color image over Rayleigh fading AWGN channel. Performance is analyzed in terms of bit error rate by MATLAB simulation. For the simulation of Rayleigh fading channel the different property values such as pat...

This paper presents performance comparison of various modulation techniques in almouti scheme with Rayleigh fading channel. In the comparison, the space time coding has been used. The performance comparison are made on the basis of symbol error rate(SER) performance matrices over Rayleigh fading channel with 16-PSK,QPSK,PAM,16-QAM,64-QAM modulation technique. The comparison results show that in...