Quasi-complementary sequence sets (QCSSs) play an important role in multi-carrier code-division multiple-access (MC-CDMA) systems. They can support more users than perfect complementary MC-CDMA It is desirable to design QCSSs with good parameters that are a trade-off of large set size, small periodic maximum magnitude correlation and alphabet size. The main results construct new infinite famili...

In this paper, based on the concept of Code Division Multiple Access (CDMA), we propose an innovative secret message multiplexing scheme by digital image data hiding. messages distributed for several participants are encoded into a CDMA codeword through and then embedded grayscale image. At receiving side, each intended recipient will be assigned distinct spreading code as key extraction. way, ...

In this paper, we propose a new fast-frequencyhopping code-division multiple-access (FH-CDMA) scheme for wireless communication systems, in which Reed-Solomon (RS) codes are modulated on top of FH-CDMA for supporting higher data rate than conventional M -ary frequency-shiftkeying FH-CDMA (MFSK/FH-CDMA) scheme and our recently proposed prime/FH-CDMA scheme. The performance of the RS/FH-CDMA sche...

Abstract-The main objective of this paper is to compare block transmission system performance analytically for Code Divisional Multiple Access (CDMA) modulations in Generalized Multicarrier environment against linear modulation techniques for both single user and multiuser. The effectivity of GMC-CDMA for multiuser will also be judged for different Direct Sequence CDMA (DS-CDMA) such as MC-CDMA...

A class of generalized multicarrier direct sequence code-division multiple-access (MC DS-CDMA) schemes is defined and its performance is considered over multipath Nakagamifading channels. The spacing between two adjacent subcarriers of the generalized MC DS-CDMA 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 syste...

1 CDMA Concept 4 1.1 Basic Principles of Spread Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1.1 Direct Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1.2 Frequency Hopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.1.3 Time Hopper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.1.4 Hybrid Systems . ....

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...