Mean Square Error Analysis in Orthogonal Frequency Division Multiplexing Systems for Least Square and Minimum Mean Square Error Channel Estimation

摘要

During the last few decades, the domain of wireless communication has experienced rapid growth. Wireless communication has become a part of almost every area of our lives, from the everyday use of smartphones to wireless applications in healthcare to providing aid during catastrophes. The two most important features for successful exploitation of wireless networks are high data rate and strong reliability. Much research is being conducted in the field of wireless communications to optimize the efficiency of signal transmission by improving bit error rate (BER) of the wireless communication systems. For improving the bit error rate, the inter-carrier interference (ICI) that occurs during the transmission of the signal has to be reduced. The conditions that can cause ICI are residual carrier frequency offset and time variations due to Doppler shift or phase noise. The orthogonality of the received signal is destroyed due to the aforementioned conditions resulting in degradation in the BER performance of the wireless systems.;Due to the need for high rate data transmission and enduring signal loss toward multipath fading and other channel impairments, a new wireless broadband technology has gained popularity: Orthogonal Frequency Division Multiplexing (OFDM). Channel estimation techniques such as least square (LS) and minimum mean square error (MMSE) for the OFDM system are analyzed and executed in this thesis. The performance characteristics of the channel of mean square error (MSE) are examined for binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), and 16 array quadrature amplitude modulation (QAM) schemes over the additive white Gaussian noise (AWGN) and Rayleigh fading channel.