International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 04 Issue: 07 | July -2017
p-ISSN: 2395-0072
www.irjet.net
Performance Evaluation of MC-CDMA for Fixed WiMAX with Equalization Avneet Kaur1, Dr. Vinit Dhaliwal 2 1M.Tech.,
Dept. of ECE, GNDU, RC Jalandhar, Punjab, India Professor, Dept. of ECE, GNDU, RC Jalandhar, Punjab, India ---------------------------------------------------------------------***--------------------------------------------------------------------2Assistant
Abstract - Multi Carrier-Code Division Multiple Access (MC-
higher data rates, it has become difficult for communication engineers to find optimum method to satisfy the needs of the users. Now the new technology has been evolved, known as the 4th generation (4G). WiMAX is a 4G technology. One multiple access technique proposed for the 4G wireless communication is Multi Carrier Code Division Multiple Access (MC-CDMA). MC-CDMA is a new wireless communication technology formulated by combining OFDM and CDMA. Therefore it utilizes the advantages of both the techniques simultaneously. MC-CDMA provides higher data rates. The transmitter and receiver for MC-CDMA system consists of both CDMA and OFDM system. The data signal is converted into parallel subcarriers, modulated converted back into single stream and then transmitted. The data signal first goes through the CDMA transmitter and then it is processed in the OFDM transmitter. On the MC-CDMA receiver the signal first gets through the OFDM receiver and then through the CDMA receiver.
CDMA) is a new RF technology which is becoming prominent in the field of wireless communication. It is providing high speed data rate in new wireless communication systems. MCCDMA is formed by combing two technologies: Orthogonal Frequency Division Multiplexing (OFDM) and Code Division Multiple Access (CDMA). MC-CDMA is used in WiMAX, Long Term Evolution (LTE), and Digital Communications. Since it is a wireless communication system therefore its generated signal will be affected by the characteristics of the wireless channel. In this paper Rayleigh fading channel and Rician fading channel models with SUI channel model parameters have been used for the analysis. The performance analysis of the system is based on Fixed WiMAX, which is a type of WiMAX. The modulation techniques used are BPSK, QPSK and 16-QAM. The objective of this research is to ascertain the performance of the system depending on Bit Error Rate (BER). The simulation and analysis of MC-CDMA system has been done using MATLAB.
1.1 OFDM System
Key Words: Orthogonal frequency division multiplexing (OFDM), WiMAX, SUI channel models, fading channels, bit error rate.
OFDM is a digital Multicarrier Modulation digital transmission technique. It has gained popularity because it has the ability to transmit data at high rates. In OFDM, original data symbols are divided into N sequences and are transmitted over N subcarriers. It is a special form of spectrally efficient technique, which employs densely spaced orthogonal subcarriers and overlapping spectrums. The use of such subcarriers makes OFDM distinguish from conventional FDM (Frequency Division Multiplexing).
1. INTRODUCTION Mobile and data services have been around for a while now since it started in 1970 and late 1980s respectively, and the demand of interference free communication and high speed data is always increasing. Electronics Communication started with analog domain and then digital domain was adopted to improve the performance of communication system. Analog modulation techniques were replaced by digital modulation techniques as for mobile communication and other related communication that were concerned. The first communication system developed was Advanced Mobile Phone Service (AMPS) which was analog. This was the 1st generation. The growing number of users forced the designers to develop new system and it was called the 2nd generation, which is a digital system. 2nd generation (2G) provided new and better services like Short Message Service (SMS), Time Division Multiple Access (TDMA), and Global System for Mobile System (GSM), IS-90 Code Division Multiple Access (CDMA). The next generation, the 3rd generation (3G) gives more services to its users like faster data rates and video services. 3G services are Universal Mobile Telecommunication System (UMTS) and CDMA2000. But with growing number of users and the requirement of
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Fig -1: Block diagram of OFDM system
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