Distributed Multiuser Sequential Channel Sensing Schemes in Multichannel Cognitive Radio Networks

Abstract

Abstract-Effective spectrum sensing strategies enable cognitive radios (CRs) to identify and opportunistically transmit on under-utilized spectral resources. In this paper, sequential channel sensing problems for single and multiple secondary users (SUs) networks are effectively modeled through finite state Markovian processes. More specifically, a model for single user case is introduced and its performance is validated through analytical analysis. Then, in order to address multiple SUs case, this model is extended to include the modified p-persistent access (MPPA) protocol. Since the scheme utilized experiences a high level of collision among the SUs, to mitigate the problem appropriately, p-persistent random access (PPRA) protocol is considered, which offers higher average throughput for SUs by statistically distributing their loads among all channels. The structure and performance of the proposed schemes are discussed in detail, and a set of illustrative numerical results is presented to validate and compare the performance of the proposed senseaccess strategies.Index Terms-Cognitive radio, spectrum handover, sequential channel sensing, queuing networks, secondary user's throughput.

Achieving Fair Spectrum Allocation and Reduced Spectrum Handoff in Wireless Sensor Networks: Modeling via Biobjective Optimization

“…In this graph, we plot the NLP relaxed and integer solutions using the original objective functions, 1 and 2 in (2) and (3), respectively. The remarkable results are as follows: (i) both the NLP relaxed solutions and integer solutions of 1 and 2 in Ω( 1 , 2 ) are apparently proportional to their respective weights; (ii) the solutions determined by the scalarization method are strictly bounded to each of the single objective solutions; (iii) the integer solutions are very close to the NLP relaxed solutions with the factor of less than 2 for both of the objective functions [14]. Next we measure how fairly the spectrum resources are allocated.…”

“…Moreover, due to the latency caused by spectrum sensing, decision, and handoff procedures, quality degradation is inevitable during spectrum handoff [12]. Hence unnecessary spectrum handoff should be eliminated [13,14].…”

Distributed random sensing order analysis and optimization in cognitive radio systems

“…In this paper, we substantially extend our previous work [15], and investigate the performance of random sensing orders for the SUs. That is, once an SHO is triggered, all the SU create a set of random channels to be sensed.…”

“…However, those proposals cannot be directly applied to a distributed CRNs. For the networks, simple SOs are proposed in [15], wherein the channels are arranged by their indices. Suppose that the SO of the n-th SU is…”

“…Therefore, QoS provisioning for the PUs is not addressed in that study. In [15], the authors exploit a modified p-persistent MAC protocol to set the SOs of the SUs in a distributed manner.…”