Mitigation of Intersymbol Interference with Equalization and Convolution Coding

In mobile radio communications, various phenomena such as multipath wave propagation, time dispersion, and fading introduce errors like Intersymbol interference (ISI), and other distortions into the signals that are transmitted over wireless channel in mobile radio communications. To combat errors, equalization (a sophisticated set of signal processing techniques), convolution coding and other schemes are employed. Equalization process compensates for channel-induced interference whereas convolution coding enable for detection and possible correction of errors in a digital mobile radio communication system. Technical computing is very powerful for simulation and evaluation of error-performance of digital data transmission. This paper gives a brief overview of adaptive equalization and the convolution coding used in mobile communication systems. Suitable algorithms for simulation of these techniques are presented here. The results are obtained using MATLAB functions and derived in the form of scatter plot and constellation of equalized signal along with filtered and ideal signal for QPSK modulation. The results show significant improvement in error-performance of digital data transmission. The analysis can be extended to include different digital modulation schemes and wireless channel characteristics.