CCECE 2004- CCGEI 2004, Niagara Falls, May/mai 2004
0-7803-8253-6/04/$17.00 ©2004 IEEE
CDMA BASED WIRELESS TRANSCEIVER SYSTEM
MATLAB SIMULATION AND FPGA IMPLEMENTATION
Zohaib Mahtab, Suhaib Jalis Ahmed, Syed Sameem Hussain, Sarwar Hasan
Dept. of Computer & Information Systems Engg., N.E.D University of Engg. & Tech. Karachi
{zohaib.online,suhaibj, sameem.hussain, server_hasan}@gmail.com
Abstract
Code Division Multiple Access (CDMA) has become
the technology of choice for the current and future
generation of wireless systems. We have implemented the
CDMA IS-95 based Wireless Transceiver System using
Matlab Simulink v 7.0. The entire system is implemented
using the Xilinx System Generator Block v6.3.
Even though the CDMA IS-95 system is already
implemented in Simulink and is provided as a demo,
there is no way of converting it into real Hardware.
Using Xilinx System Generator we have made our
implementation capable of being translated into any of
the HDL codes. This can be then mapped onto
appropriate FPGA easily. We have used the hardware
co-simulation feature of the Xilinx System generator to
create a library of the basic building blocks of the IS-95
system. This library can be used for implementing to
create the various channels that are the part of the
CDMA system.
Keywords: CDMA, CRC, Convolutional, Interleaver, PN
Sequence, Walsh codes, Viterbi decoder.
1. INTRODUCTION
Code Division Multiple Access (CDMA) has become
the technology of choice for the current and future
generation of wireless systems. IS-95 based CDMA
systems developed by TIA have been widely deployed in
the U.S. and around the world [1]. The IS-95-A design
provides superior multiple-access capabilities, in addition
to a number of other desirable attributes for wireless
cellular service. These attributes include optimum
subscriber station power management, universal
frequency reuse, soft handoff, and enablement of the use
of optimum receiver structures for time-varying
multipath fading channels [1]. We assume that the reader
has some familiarity with CDMA principles and the IS-
95-A standard, in particular.
Simulink, which runs in MATLAB, is an interactive
tool for modeling, simulating, and analyzing dynamical
systems. The Xilinx System Generator [8], a high-
performance design tool, runs as part of Simulink. The
System Generator elements bundled as the Xilinx
Blockset appear in the Simulink library browser. It
provides some basic block for system design. The
Bottom-Up approach for the system development is used,
wherein we have divided the sub-modules of the system
into the basic leaf blocks, so that they can be mapped
with the provided library blocks.
This paper is organized as follows. In section 2
System Architecture is explained. Section 3 deals with
the implementation of the whole architecture. Synthesis
and the results are discussed in Section 4. Finally the
paper is concluded in section 5.
2. SYSTEM ARCHITECTURE
In this section the complete system architecture has
been discussed.