Spectrum Sharing in Cognitive Radio Work Using Goodput Mathematical Model for Perfect Sensing, Zero Interference and Imperfect Sensing, Non Zero Interference
Festus Kehinde Ojo · International Journal of Wireless Communications and Mobile Computing · 2015
In recent years, there has been increase in the demand for spectrum allocation as wireless communication witness rapid growth on a daily basis. Literatures have established that this spectrum is scarce and more than 70% of the available spectrum is not utilized optimally. This paper proposes a model called Goodput model by which the under-utilized spectrum can be shared effectively between primary users and the secondary users without causing harmful interference between the users and also find solution to the problem of increasing demand for spectrum allocation on an already scarce spectrum. Goodput is a mathematical modeling in which the total amount of primary and secondary data that is successfully delivered per unit time can be used as performance index. Compared to other models, the Goodput model with zero interference, perfect sensing and imperfect Sensing, non-zero interference is used to determine the secondary users that will be able to use unoccupied portion of radio frequency channel of primary users with different values of data probability of arrival. Result shows that, the point of intersection between np and N(1-p) is the optimum point of interference, where n,N,and p are number of secondary users, number of primary users, and Probability of data arrival rate respectively. Below the optimum point of interference (left side of the point), all the secondary users will transmit opportunistically without interference. However, above the optimum point of interference (right side of the point), there will be interference between any secondary users that attempt to transmit.