Exploiting the Direct Communication Link for Enhancing Effective Capacity Performance of Cognitive Radio Relay Networks

摘要: Nowadays, cognitive radio (CR) is a promising concept to improve the spectrum exploitation. CR has tremendous ability enhance efficiency by allowing secondary users (SUs) access licensed resource which currently not being used primary (PUs). One basic challenge of that paradigm securing quality service (QoS) link transmission while increasing rate links transmission. Cooperative relaying an encouraging technology offers opportunity maximize diversity gain significantly in rapid development growth wireless communication contains networks. On other hand, effective capacity (EC) designed provide maximum constant arrival statistical channels can support satisfying QoS requirements. In this thesis, performance enhancement analysis relay network (CRRN) exploiting direct been investigated Rayleigh fading channel where peak interference power constraint taken into consider. A sharing technique considered thesis restriction applied PUs. Here, SU coexist simultaneously with PU for transmitting data as long certain threshold on receiver overstepped SUs addition, it supposed there are multiple intermediate nodes available transmit their signal destination along Moreover, meet random delay constraint. By providing constraint, be achieved small error probability. Specifically, also acquires closed-form expressions EC CRRN. It evident if and set changed, then changed. verified together higher gains compare non-direct Matlab simulations presented find out theoretical results Monte-Carlo carried these numerical results. Both simulation analytical match very well.