ABSTRACT

 This work titled: Effect of Phase Noise in 256-QAM---A Computer-Based Study, -4 is mainly aimed at studying how phase noise affects 256-quadrature amplitude modulation. The other aim is to determine the relationship between the phase noise level density and the Error Rate (that is the rate at which error is occurring between the transmitted signal and the received signal). The last aim is to proffer a technical solution on how the effect of phase noise in 256-QAM can be drastically reduced. In going about the work, experiments were performed for fourteen different frequency offsets. For each frequency offset, the value of the phase noise level density in the Phase Noise block was varied from -20dBcfHz to -120dBcfHz in steps of -20. A model (that is capable of simulating the effect of phase noise in 256-QAM), published in MATLAB 7.1 version was used to carry out these experiments. Little adjustments were made on the model before using it. The results obtained show that as the phase noise level density values decrease, the effect of phase noise in the quadrature amplitude modulated signal also decreases, though not uniformly across the intervals. Again, results show that the rate at which error is occurring between the transmitted signal and the received signal is proportional to the phase noise level density. This work is of benefit to communication companies.