Abstract:
The aim of this thesis work is to design a smart antenna based receiver in an
Orthogonal Frequency Division Multiplexing (OFDM) system to improve the
system performance and to reduce the computational complexity. OFDM is a
special form of multi-carrier transmission that promises a higher data rate and
greater resilience to severe signal fading effects at a reasonable level of implementation
complexity. OFDM with multiple receiver antennas combine the different
receiver signals. This type of OFDM system minimizes fading effects and thereby
shows significant improvement in the system performance. However, each of the
receivers has its own Fast Fourier Transform (FFT) Block, so the system complexity
increases by the combination of receiver signals. To reduce the complexity
of the OFDM system, a smart antenna system based Pre-FFT Maximum Ratio
Combiner (MRC) is proposed. In the proposed scheme, only one FFT block is
used instead of multiple FFT blocks in the receiver end. The received signal are
weighted and combined before FFT processing. As a result, the number of FFT
blocks reduces and the computational efficiencyincreases. A mathematical model
of the proposed system is developed and the analytical formulation of Bit Error
Rate (BER), channel capacity and throughput are also presented. Finally, the.
performance of the pre-FFT MRC receiver and single receiver are evaluated and
compared in terms of BER and other parameters. Computer simulation result
shows a significant improvements in Signal-to-Noise.Ratio (SNR) for the proposed
receiver.
