The problem of estimating propagation delays of the orthogonal modulated signals in asynchronous DS-CDMA system over fading channels is treated 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. The shortcoming of the sliding correlator as the standard method of code acquisition is examined and ...

Abstract – In this work we consider the problem of locating a known periodically embedded synchronization pattern in random data, which is subject to flat fading and additive white Gaussian noise. We derive the maximum likelihood rule and its high-SNR approximation for the case of noncoherent demodulation and show experimental results for the slow-fading Rayleigh channel. It is shown that the w...

Interleaving enhances the quality of digital transmission over the radio fading channel. This enhancement comes at the cost of introducing additional time-delay, memory space requirements, and system complexity. This paper describes commonly used interleaving techniques. It addresses the realization and performance of a convolutional interleaver that cuts down time-delay and memory space increa...

We consider a single input single output (SISO) flat Rayleigh block fading channel with L blocks. This model arises when the coherent time of the channel is much longer than one symbol interval (such as GSM, IS54-TDMA) [1], or in cooperative systems where partner mobiles help the original node transmit parts of the codeword [2]. For the block fading channel, the averaged pairwise error probabil...

Jakes model for frequency flat fading processes in mobile radio systems is extended to allow for better modelling of a space-time Rayleigh fading multiple-input multiple-output (MIMO) channel. A conventional four transmit and two receive (4,2) MIMO radio channel is analysed, and a ring of scatterers model is used to find the fading channel distortions. A base station antenna spacing for appropr...

Low Complexity Channel Models for Approximating Flat Rayleigh Fading in Network Simulations. (August 2003) Jeffrey Michael McDougall, B.S., Texas A&M University; M.S., Johns Hopkins University Chair of Advisory Committee: Dr. Scott L. Miller The intricate dependency of networking protocols upon the performance of the wireless channel motivates the investigation of network channel approximations...

ABSTRACT This paper analyzes a CDMA system with a continuous uniform source, a scalar quantizer, and a hard decision block channel coder, under the constraint of fixed total bandwidth. The system employs a linear, minimum mean-square-error (MMSE) receiver for interference suppression. We study the performance for both additive white Gaussian noise (AWGN) and flat Rayleigh fading channels. The a...

Pilot Symbol Assisted Modulation (PSAM) channel estimation techniques over Rayleigh fading channels have been analysed in recent years. Fluctuations in the Rayleigh fading channel gain degrades the performance of any modulation scheme. This paper develops and analyses a PSAM Polynomial interpolation technique based on Least Square (LS ) approximations to estimate the Channel State Information (...

In this paper, modulation classification of digitally modulated signals is done using Linear Discriminant Analysis (LDA) under the influence of additive white guassian noise (AWGN) as well as the channel effect such as fading. The modulations considered for the classification purpose are PSK 2 to 64, FSK 2to 64 and QAM 2 to 64. The channels considered throughout the simulations are AWGN, Raylei...