This paper presents a technique to mitigate multiple access interference (MAI) in multicarrier code division (MC-CDMA) wireless communications systems. Although under normal circumstances the MC-CDMA system can achieve high spectral efficiency and resistance towards inter symbol (ISI) however when exposed substantial nonlinear distortion issue of MAI manifests. Such results power amplifiers are...

Z-complementary sequence sets (ZCSSs) can be applied to multi-carrier code division multiple access (MC-CDMA) systems as user address codes eliminate multi-path interference and multi-access interference. In this paper, two constructions of ZCSSs are investigated. First all, flexible diverse seed employed generate a large number optimal ZCSSs, which is generalization an existing construction. N...

Spectrum efficiency of CDMA compared with TDMA. CDMA Vs TDMA in travel. Differences between CDMA and TDMA.WCDMA is Wideband CDMA that still uses code division to divide the channels. The most major difference between CDMA and WCDMA is in the group of.Its first of the two part lectures which will cover GSM and CDMA, the. SIM is portable and therefore transferable between mobile stations or your ...

A class of unified multicarrier DS-CDMA (MC DS-CDMA) schemes is defined and its performance is considered over multipath Nakagamim fading channels. The spacing between two adjacent subcarriers of the unified MC DS-CDMA scheme is a variable, allowing us to gain insight into the effects of the spacing on the bit error rate (BER) performance of MC DS-CDMA systems. This unified MC DS-CDMA scheme in...

Multicarrier Code Division Multiple Access Schemes (MC-CDMA) have been recently introduced in existing CDMA based systems to improve security, data transmission rate and to minimize Inter Symbol Interference (ISI). CDMA experiences severe multipath fading which badly affects its performance. By transmitting identical narrowband DirectSequence (DS) waveforms using frequency diversity, in paralle...

Multicarrier Code Division Multiple Access Schemes (MC-CDMA) have been recently introduced in existing CDMA based systems to improve security, data transmission rate and to minimize Inter Symbol Interference (ISI). CDMA experiences severe multipath fading which badly affects its performance. By transmitting identical narrowband DirectSequence (DS) waveforms using frequency diversity, in paralle...

A hybrid pulse interval modulation – code division multiple access (PIM-CDMA) is proposed. Expression for bit error rate (BER) is given. Numerical results presented are compared with hybrid PPM-CDMA and OOK-CDMA schemes. For a low number of users PIM-CDMA achieves similar and marginally lower BER performance compared with PPM-CDMA and OOK-CDMA, respectively. For large number users it offers bet...

Low signal to noise ratio (SNR) channels require careful design of communication systems in order operate reliably such extreme channels. Special measures and techniques must be considered when designing for environments counteract the effect high power. Channel coding is a powerful tool aid against adverse channel conditions including low SNR. Coupling with spreading technique can further stre...

The need for a communication system with higher data rate and mobility grows along information technology development. Combining MC-CDMA the MIMO supporting good transmit diversity technique is promising idea to provide needed system, especially in high conditions. can support ubiquitous communications without affecting achievable BER more capable of high-speed mobility. It integrates benefit b...