Performance Analysis and BER Comparison of 4x4 MIMO OFDM System over Rayleigh and Rician Fading Channel

Abstract

In modern days, we are using wireless modern communication systems, which require high data rates and more band width efficiencies. The most well-known 4G technology of wireless standard is Long Term Evolution (LTE) which espoused OFDMA (Orthogonal Frequency Division Multiple Access) and MIMO (Multi Input Multi Output) techniques. These techniques are employed on downlink of LTE.A MIMO system uses multiple antennas at both the transmitter and receiver to improve the communication system performance by use of diversity and multiplexing techniques. MIMO system provides higher spectral efficiency, improves the reliability, fading mitigation and improved resistance to interference. Hence analyzing the performance of OFDMA and MIMO using 16-QAM, 64- QAM and QPSK modulation over Rayleigh and Rician fading channels by using BER (Bit error Rate)for the performance evaluation of the LTE system in downlink the proposed system determines the Bit Error Rate of the system for MIMO system applications. For the modulation on message three supported modulation schemes in LTE namely 16-QAM, 64- QAM and QPSK are applied and then with the use of OFDM the information is transmitted over the network where the signal is distorted by the noise addition using the Rayleigh and Rician Fading channel. Then AWGN is added to model the actual scenario of the transmission medium. At the receiver side this signal is received and the OFDM demodulation is performed then as per the received bits the BER is calculated and then the result is compared among the modulation scheme and the bandwidth used for basically two fading channel types namely Rayleigh and Rician Fading channel.