This paper presents a novel multiple access scheme for future mobile communications using Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA) and Code Division Multiple Access (CDMA). The proposed system can support different classes of users each with different data rates and can provide very high spectral and system efficiency for the uplink and downlink. It is abl...

Direct-sequence optical code division multiple access technology is one efficient and simple way to reduce the multiple access interferences that existed in visible light communication system due to its ease implementation by simply turning the light-emitting diodes (LEDs) on and off. To overcome the multi-path effect and non-perfect clock impairment, an optical zero correlation zone code set i...

orthogonal frequency division multiplexing – interleave division multiple access (OFDM-IDMA) have been proposed for beyond third generation (B3G) and fourth generation (4G) communication systems. These system are based on iterative multiuser detection (MUD) techniques. The efficiency of these systems is dependent on the generation of efficient user specific interleavers on the basis of which th...

Multi carrier code division multiple access (MC-CDMA), a strong contender for future mobile communication is a combination of orthogonal frequency division multiplexing (OFDM) and code division multiple access (CDMA). Turbo coding technique can be used for improving the performance of MC-CDMA system in terms of bit error rate (BER). The objective of this work is to form a coding scheme that red...

This paper presents a novel chaotic spreading sequence for multiple input multiple output multi-carrier direct sequence code division multiple access (MIMO MCDS/CDMA) systems. The effect of multiple access interference can be mitigated by choosing the spreading sequences with appropriate cross-correlation properties. The performance of the system is analysed in multiuser scenario with the aid o...

Optical code division multiple access (OCDMA) provides another dimension to multiple access systems, in which each user is assigned a unique code. This allows each subscriber to simultaneously access the medium without any contention. However, simultaneous access of multiple users introduces multiple access interference (MAI) which primarily deteriorates the performance of OCDMA systems. This p...

We address the problem of joint beamforming and multipath channel parameters estimation in Wideband Code Division Multiple Access (WCDMA) communication systems that employ Multiple-Access Interference (MAI) suppression techniques in the uplink (from mobile to base station). Most of the existing schemes rely on time multiplex a training sequence with the user data. In WCDMA, the channel paramete...

A complete complementary/prime/shifted prime (CPS) code family for the optical code-division multiple-access (OCDMA) system is proposed. Based on the ability of complete complementary (CC) code, the multiple-access interference (MAI) can be suppressed and eliminated via spectral amplitude coding (SAC) OCDMA system under asynchronous/synchronous transmission. By utilizing the shifted prime (SP) ...