Cognitive radios have been facing spectrum sensing challenges due to interference and congestion within the spectrum which have been brought about by the increased number of high data rates devices that use multimedia application as compared to the voice only communication that has been previously in use . This compromises the transmission of the radio waves. Though these radios are in a position to sense the spectrum and identify an idle or unused spectrum, the current sensing techniques are not in a position to perform well in this radio crowded environment. The aim of this paper is to present a systematic review of the available evidence based on literature concerning how to improve spectral utilization in the environment to enable development of sophisticated sensing techniques . In their paper of spectrum sensing algorithm for cognitive radio applications, they focused on cooperative sensing concept . This paper will focus on the sensing method algorithms together with the spectrum measurement techniques used. In their paper they dealt with large scale spectrum measurement study. This paper will also focus on the measurement of channel vacancy duration which will play a big role in the sensing technique . The results obtained from the sensing methods algorithms and measurement of channel vacancy duration will be used to improve the spectral utilization by the cognitive radios. The approaches used in these papers will be compared by determining the relevance of the result to the development of the sophisticated sensing technique
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