Implementation of Orthogonal Frequency Division Multiplexing for SDR using MATLAB

Abstract

Wireless Communication system is the emerging field of research. Users need to do many changes in the hardware to obtain high data rate less latency for less cost. To avoid Inter Symbol Interference (ISI) in a single carrier system, delay time must be very less compared to the symbol period. The data rate is inversely proportional to the symbol period. The low data rate is, due to the long symbol period. System with long symbol period h is not considered as an efficient communication system. The multi carrier system like Frequency Division Multiplexing (FDM) technique, the available bandwidth is used for multi carrier transmission by dividing the total bandwidth to sub bands. To obtain high data rates, the multiple carriers can be placed closely in the spectrum. But due to the less gap between multiple carriers in the spectrum, there is a chance of having Inter Carrier Interference. To avoid this interference guard bands need to be inserted which in turn results in low data rate. This paper focuses on the Orthogonal Frequency Division Multiplexing (OFDM) system implementation for testing purposes and its verification. Most of the stages in a communication system can be replaced by the software. For this process a new system called software defined radio came to exist. SDR is a radio which can be used for signal processing with minimum cost. The main goal is to create an OFDM signal using MATLAB for signal processing, synchronization, equalization, demodulation and detection. The paper also gives the design of an OFDM transmitter and receiver for Software Defined Radio.