A novel interference reduction technique in game theory based dynamic spectrum leasing scheme
Gayathri R. Nair, Yamuna K. Moorthy, Sakuntala S. Pillai · 2016
A price based spectrum sharing scheme is considered where a primary user allows certain secondary users to access its unused licensed band opportunistically or with coexistence. While in coexistence, network of multiple users, competing for the same idle spectrum, ends up causing intolerable interferences to the primary receiver. Since PU is of prior importance, any kind of interruption to its transmission is not desirable. Most of the works, tries to employ the same interference management technique in both primary and secondary network. An improved interference alignment technique is proposed which can be implemented in the secondary network itself to reduce the effect of interference created at primary receiver. This will eliminate the burden of having variable filter coefficients at the primary according to the changing number of users in the secondary network. Also, by making use of the orthogonality property of interference alignment filters of SUs, SINR at each secondary receiver is maximized. Since the idle spectrum of PU is a valuable commodity and many users are competing for the same time, there arises conflict among them in taking decisions. The spectrum allocation problem is formulated under Stackelberg game framework. The equilibrium point is found through proposed game theoretic search algorithm using backward induction process and optimal strategies are obtained. The system model is implemented through the proposed block architecture in Matlab. Simulations are carried out to study the proposed system and the performances are verified under various network conditions. An improvement in performance of utility is observed for the proposed method.