ANALYSIS OF EQUALIZED OFDM IN 3G COMMUNICATION SYSTEMS

Abstract

The goal for the third generation of mobile communications system is to integrate a wide variety of communication services such as high speed data, video and multimedia traffic as well as voice signals. In this situation the OFDM (Orthogonal Frequency Division Multiplexing) communication system is a suitable option for high band width data transmission, by converting the wideband signal into a parallel narrow band signals for parallel transmission. The transmission of these individual narrow band signals are executed with orthogonal frequency carrier. And Under the Universal Mobile Telecommunication System (UMTS) environment the Third Generation (3G) has many advantages such as highly efficient spectrum utilization and variable user data rates. In this paper, we present the bit error probability (BEP) performance analysis of Rayleigh Fading Channel with BPSK and QPSK modulation technique and the linear pilot–assisted channel estimation receiver. Each narrowband OFDM signal suffers from frequency fading and, thus, needs a one-tap equalizer to compensate for the corresponding channel distortion. The Channel estimation is usually needed to compensate for the amplitude and phase distortions associated with a received orthogonal frequency-division multiplexing (OFDM) waveform. This paper also presents a systematic approach for analyzing the bit-error probability (BEP) of equalized OFDM signals in Rayleigh fading. The data is modulated, encoded, spread and transmitted through a frequency selective Rayleigh fading channel.