PERFORMANCE ANALYSIS OF CODED OFDM FOR DIFFERENT CHANNEL MODELS ON SDR PLATFORM by Ashish Thakur
Abstract
With the tremendous growth in the demand for high-speed reliable wireless communication systems
worldwide, Orthogonal Frequency Division Multiplexing (OFDM) technique holds the promise for
achieving the spectral efficiency and high data capacity requirements for the upcoming wireless standards of the near future. It has other advantages such as its ability to reduce the inter symbol interference (ISI) and to handle the severe channel conditions. It is being widely used for recent wireless communication systems like 5G mobile communication, satellite communication and LTE systems. Coding of OFDM using Forward Error Correction (FEC) codes such as convolution coding helps in the transmission of source code in such a manner that the error probability minimizes over the crowded noisy channel by systematic addition of redundant bits. It reduces the bit error rate, hence improvement in reception. Convolution coding has ability for real time error correction. Along with it, Software Defined Radio platform being recently introduced has provided solutions to implement multiple standards on same platform without any alterations in hardware because it provides the entire signal processing functions at the software. It has provided with flexible, low cost and reliable solutions and also it has ability to incorporate artificial intelligence and to support future devices. Till now, FEC coding of OFDM has been implemented on SDR platform, but the impact of FEC on OFDM performance over both AWGN and fading (Rayleigh and Rician) channels in term of Bit Error Probability has not been studied. So the simulation of Coded OFDM on SDR and its performance under different channel models has been analyzed in this work. In this work via GRC simulations, it has been analyzed that the Coded OFDM has outperformed uncoded OFDM under all the considered channel models. The Coded OFDM with FFT length of 1024 with QAM 256 modulated data has outperformed uncoded OFDM by 6.57% and for Rician and Rayleigh channel, it has improved performance by 3.46% and 6.24% respectively. The systems based on Coded OFDM has better data rates, spectral efficiency and requires lower transmission power as compared to the Uncoded OFDM based systems under the considered channel models.
