The paper addresses the blind equalization problem of spread spectrum modulations in the presence of fast time-variant frequency selective channels. The basic assumption of the paper is that the channel response exhibit fast changes. A second goal of the paper is to force the definition of a universal CDMA blind equalization scheme that is capable to perform for DSCDMA or Multi-Carrier CDMA sig...

Wireless communication systems targeting at broadband and mobile data transmissions commonly face the challenge of fading channels which are both time and frequency selective. Therefore, the design of effective equalization and estimation algorithms for such channels becomes a fundamental problem of communication systems. On one hand, multi-carrier transmission systems demonstrate prominent pot...

Multi-carrier code division multiple access (MC-CDMA) is modulation method for high speed data communication. The usage of MIMO MCCDMA can significantly improve the performance of wireless communication system. This paper presents the analysis of Multi Input Multi Output MultiCarrier CDMA system performance for BPSK, QPSK, MSK modulation over AWGN channel and Rayleigh channel. This represents t...

in this paper, for the purpose of investigating horizontal sound propagation, based on the results obtained from practical measurements in the strait of hormoz and available data on sound speed variations at different depths, a comprehensive model for shallow water multipath underwater acoustic channel is presented. mathematical modeling of multipath effect is based on ray theory and the image ...

—In this paper, a new non-coherent chaos-based communication scheme, named orthogonal frequency division multiplexing based different chaos shift keying (OFDM-DCSK), is presented inspired by multi-carrier direct sequence codedivision multiple access (MC-DS-CDMA) system, multi-carrier DCSK (MC-DCSK) system, and channel estimation of OFDM system. In this scheme, all of the occupied subcarriers a...

This paper proposes a channel estimation technique for the dynamic parameter controlled — orthogonal frequency and time division multiple access (DPC-OF/TDMA) systems studied as one of the candidates of the beyond third generation (B3G) systems. In the proposed scheme, the impulse response, which represents the channel state information (CSI) is estimated using carrier interferometry (CI) which...

Abstract: The application of Wiener filtering to the detection of Multi-Carrier Code Division Mult iple Access (MC-CDMA) signals is analyzed. An analytical model is developed to evaluate an MCCDMA system with a very large number of subcarriers. This model is compared with simulations for 8 and 64 subcarriers. Simulation results are also presented on the effect of correlated fading (in the frequ...

In this paper, the channel estimation methods for OFDM systems based on comb-type pilot sub-carrier arrangement are investigated. The channel estimation algorithm based on combtype pilots is divided into pilot signal estimation and channel interpolation. The pilot signal estimation based on LS or MMSE criteria, together with channel interpolation based on piecewise-linear interpolation or piece...

This paper proposes a Multi-Code Multi-Carrier CDMA, best suited for multi-rate services using multicode schemes and multi-carrier services used for high rate transmission as required for the Universal Telecommunication Mobile Systems (UMTS) Long Term Evolution (LTE). The system performance has been analyzed and evaluated by means of signal-to-noise plus interference ratio and bit error rate un...

The multicarrier technique is known since more than 40 years. First practical applications, however, were not considered before 1990 when Bingham’s famous paper appeared which pointed out the great attraction of this idea – especially in the form of the FFT-based ”OFDM” (Orthogonal Frequency Division Multiplexing). Meanwhile, OFDM is applied in the DAB and DVB standard (Digital Audio/Video Broa...