Performance assessment of STBC-OFDM system using different transforms over LOS and NLOS channel

Abstract

Modern day users demand a robust communication that too an elevated data rate. These expectations can only be fulfilled by a hybrid combination of multiplexing techniques likes of orthogonal frequency division multiplexing (OFDM) and multiple input multiple output (MIMO) antenna systems. OFDM methodology takes care of elevated data rate requirements whereas MIMO facilitate the enhanced reliability, low bit error rate (BER) and higher spectral efficiency characteristics. The performance of conventional MIMO-OFDM system can further be enhanced by utilizing various transforms like fractional Fourier transform (FrFT) or discrete wavelet transform (DWT) in place of traditional fast Fourier transform (FFT) in OFDM. A comprehensive analysis of bit error rate (BER) and spectral efficiency for conventional MIMO-OFDM system based on FFT, FrFT, and DWT has been presented in this paper. The simulated outcome shows a significant reduction in BER and improvement in spectral efficiency in the DWT-based MIMO-OFDM system.