In this paper, the capacity of the Code Division Multiple Access Wireless Local Loop (CDMA WLL) system is analytically derived, and the capacity gain achieved in a CDMA WLL over a cellular mobile environment is calculated. The results show that the CDMA WLL system can support up to 36 % more users than CDMA cellular mobile system. The paper also propose a new approach to increase the reverse li...

In this paper, we analyze capacity and spectrum utilization of spectrally overlaid systems using single-code CDMA (SC-CDMA) and multi-code CDMA (MC-CDMA) techniques according to varying system parameters. The spectrum utilization defined as maximally achievable total throughput in the overlaid systems is compared with that of the un-overlaid systems. Analytical results show that the dominant pa...

For the reception of multicode direct sequence (DS)-CDMA signals, the MMSE frequency domain equalisation is applied instead of RAKE combining. The achievable BER performance in a frequency selective Rayleigh fading channel is evaluated by computer simulation. It is shown by computer simulation that the DS-CDMA with MMSE frequency domain equalisation outperforms the DS-CDMA with RAKE combining a...

We investigate the possible role of optical CDMA (O-CDMA) in future access networks. We begin with a short review of the O-CDMA technique for those unfamiliar with the technology. Next, we investigate in detail those characteristics of O-CDMA that make it an attractive technology for application in metro access networks: fairness, flexibility, simplified network control and management, service ...

Escalating demand of higher data rate in progressive generations for wireless environment involve work towards modification of modulation schemes over air interface. Beginning from TDMA/FDMA/CDMA based 2nd generation to highly complicated Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Interleaved FDMA (IFDMA) and Multicarrier CDMA (MC-CDMA) which are gaining attention for 4G networks. ...

Many recent standards in telecommunications field are based on CDMA spread spectrum transmissions. In this paper, we describe a methodology for top-down design, modeling, and simulation of CDMA transmitter system using hardware description language VHDL-AMS. Details of VHDL-AMS implementation for each elementary block are shown. This paper together with the developed library of CDMA transmitter...

In this contribution, we consider the effect of carrier phase jitter on the performance of uplink OFDMA, uplink multicarrier CDMA (MC-CDMA) and uplink multicarrier direct sequence CDMA (MC-DS-CDMA) systems, assuming orthogonal spreading sequences. For this aim, it is proposed, first to consider a small random jitter, then, to model phase jitter by Gaussian and Rayleigh laws. Theoretical express...

This work is aimed at investigating the use of neural network-based adaptive receivers for synchronous variable bit-rate Multi-Carrier CDMA systems transmitting over low-earth-orbit (LEO) satellite channels. It is known by literature that MC-CDMA techniques are much more resilient with respect to multi-user interference effects in multipath fading channels than single-carrier DS/CDMA ones. More...

Random Packet CDMA: Reducing Delay and Increasing Throughput of WLAN Systems Roland Kempter and Behrouz Farhang-Boroujeny Department of Electrical and Computer Engineering, University of Utah, USA Abstract— We revisit Random Packet Code Division Multiple Access (RP-CDMA), a recently proposed Physical/MAC layer scheme for wireless CDMA networks. We revise earlier results by adopting a more reali...