Spectrum Sensing for Cognitive Radio : State-of-the-Art and Recent Advances

Time-efficient cooperative spectrum sensing via analog computation over multiple-access channel

“…By controlling the reporting order of local statistics, the global statistic at the fusion center accumulates faster than the case without order control. More related works can be found in the recent surveys on CSS [26,27] .…”

“…2 Correspondingly, the fusion center decodes each received local statistic separately and finally computes the overall test statistic which in this paper turns out the weighted arithmetic mean of the collected local statistics. The drawback of conventional CSS schemes [26,27] is the large reporting delay, especially when the CRN scales. Code division multiple access (CDMA) and orthogonal frequency division multiple access (OFDMA) can allow SUs to transmit concurrently in the same time slot their local statistics to the fusion center.…”

Discrete time analysis of cognitive radio networks with imperfect sensing and saturated source of secondary users

“…These functions rely on signal processing techniques and are usually known as spectrum sensing algorithms. In the literature, a number of spectrum sensing algorithms have been proposed (see [3,26,27] for an overview). Although it is an important part of the sensing strategy, the spectrum sensing algorithm itself is outside the scope of this paper and its detailed operation is not described by our model.…”

In-band Spectrum Sensing Method Based on Guard Frequency Bandwidth for Cognitive OFDM Systems

“…So, cognitive radio technology [1][2][3][4][5] has been developed to allow unlicensed system (secondary system) to exploit spectrum of licensed system (primary system) opportunistically. Thus the spectrum allocation problem can be solved and the spectrum utilization efficiency could be promoted greatly [6][7][8][9]. OFDM (Orthogonal Frequency Division Multiplexing) is accepted as the most promising technique for next generation wireless communication system.…”