Smart Antennas for Code Division Multiple Access Systems

Author(s):  
Salman Durrani ◽  
Marek E. Bialkowski

This chapter discusses the use of smart antennas in Code Division Multiple Access (CDMA) systems. First, we give a brief overview of smart antenna classification and techniques and describe the issues that are important to consider when applying these techniques in CDMA systems. These include system architecture, array antennas, channel models, transmitter and receiver strategies, beamforming algorithms, and hybrid (beamforming and diversity) approach. Next, we discuss modeling of smart antennas systems. We present an analytical model providing rapid and accurate assessment of the performance of CDMA systems employing a smart antenna. Next, we discuss a simulation strategy for an adaptive beamforming system. A comparison between the analytical results and the simulation results is performed followed by a suitable discussion.

2013 ◽  
Vol 284-287 ◽  
pp. 2687-2693
Author(s):  
Ing Jiunn Su ◽  
Chiao Chan Huang

In this letter, we present a blind carrier frequency offset (CFO) estimator by exploiting the polynomial rooting technique for multicarrier-code division multiple access (MC-CDMA) systems. Relative high accuracy and low-complexity to the CFO estimation can be achieved by rooting a polynomial. Simulation results are provided for illustrating the effectiveness of the proposed blind polynomial rooting estimator.


Author(s):  
Bouasria Fatima

<p>In this paper our objective focuses on the development of digital transmission techniques in order to solve the problem of Inter-Symbol Interference (ISI) due to multiple paths and the improvement of Multi-Carrier Code Division Multiple Access (MC-CDMA) system performance. The both algorithm: MERRY algorithm (Multicarrier Equalization by Restoration of Redundancy) called TEQ (Time domain EQualizer) and the power allocation method to allocate appropriate power to each user (Water-filling technique (WF)) [1] is used. Finally, the numerical results show that combining Water Filling with TEQ technique allows to reduce the ISI for MC-CDMA systems.</p>


2016 ◽  
Vol 37 (2) ◽  
Author(s):  
N. Alsowaidi ◽  
Tawfig Eltaif ◽  
M. R. Mokhtar

AbstractIn this paper we introduce a successive interference cancellation (SIC) scheme for direct sequence optical code division multiple access (DS-OCDMA) systems using pulse position modulation (PPM). Considering double-padded modified prime code (DPMPC) as a signature sequence code, results show that the system has better performance in terms of both capacity and bit error rate (BER) as compared to the one without cancellation scheme, where the system with SIC scheme can support up to 88 users while the system without SIC scheme can support only 38 users at similar BER=10


2014 ◽  
Vol 8 (5) ◽  
pp. 56 ◽  
Author(s):  
A. Hameed ◽  
Ali Oudah

This paper addresses the key characteristics of interference in wireless networks. Moreover, it considers the impact of interference from Code Division Multiple Access base station to Wideband-Code Division Multiple Access one. A detailed discussion of major interference mitigation techniques in wireless networks, in general, and CDMA and W-CDMA systems, in particular is also imparted on. The techniques and findings in this paper can be easily used in the analyses of other wireless technologies.


1998 ◽  
Vol 08 (10) ◽  
pp. 2047-2059 ◽  
Author(s):  
Tao Yang ◽  
Leon O. Chua

Chaotic digital code-division multiple access ((CD)2MA) systems are new types of communication systems using chaotic carriers. (CD)2MA had found applications in both wireless and other communication systems. In this paper we study the error performance of chaotic digical code-division multiple access ((CD)2MA) systems used in both wireless environment and cable networks. We present first the details of the interleave mode of the (CD)2MA. When a (CD)2MA system works in the interleave mode, each of its transmitters only transmits signals during a portion of the bit duration of the message signal. The total interference level is thus reduced which in turn increases the channel capacity. The relationship between the bit error rate (BER) and the interleave rate is studied in both the synchronous (CD)2MA system used in cable systems, and the asynchronous (CD)2MA system used in wireless environments. Our simulation results show that in a cable system the synchronous (CD)2MA system can support 1.5 times more channel capacity than synchronous CDMA systems, and double the channel capacity of CDMA systems in wireless environments.


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