With the increasing growth in the wireless communication systems, the bandwidth requirement is also continuously increasing, and the increasing demands make the wireless communication resources more and more scarce. Cognitive radio technology facilitates an effective solution for bandwidth scarcity through a process of dynamic and opportunistic spectrum sharing over heterogeneous wireless networks. However, the fundamental goal of the 5G communication system based network is to offer extended coverage, a very high data transfer rate, massive connectivity with minimum latency as performance metrics of 5G communication system. To achieve these requirements, the 5G systems exploit the spectrum range from 30Ghz to 300GHz. This paper presents various aspects of theoretical background that relate the research insights of cognitive radio technology, spectrum sharing, and 5G communication system. The inferring of the research evolution and trends in the domain of the collaborative study of spectrum sensing, cognitive radio, and 5G provides future research directions based on the research gap analysis