scholarly journals Outage Analysis of Cognitive Communication System Using Opportunistic Relay Selection and Secondary Users as Relays

2021 ◽  
Author(s):  
Hojjat Javadzadeh ◽  
abdulhamid zahedi
Keyword(s):  
Outage Probability ◽  
Communication Systems ◽  
Relay Selection ◽  
Bandwidth Utilization ◽  
Decode And Forward ◽  
Secondary Users ◽  
Idle State ◽  
Primary Users ◽  
Opportunistic Relay Selection ◽  
Outage Analysis

Abstract Efficient bandwidth utilization is significant in new communication systems where secondary users can be used besides of primary users considering interference issues and idle state of primary users. Using secondary users as relays to transmit their own signals in addition to the primary signals can be applied for more reliability of the system where opportunistic relay selection can significantly enhance the performance of the system. The best-condition secondary user is selected as the optimum relay for retransmission of primary/secondary signal. Outage probability is analyzed in this paper based on decode and forward techniques in secondary users while the closed-form statement for outage probability is provided and verified by numerical evaluations.

Interference Modeling and Analysis in Cognitive Radio Networks

2013 ◽  
Vol 4 (4) ◽  
pp. 1-15
Author(s):  
Yanxiao Zhao ◽  
Bighnaraj Panigrahi ◽  
Kazem Sohraby ◽  
Wei Wang
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Cognitive Radio Networks ◽  
Critical Role ◽  
Radio Networks ◽  
Secondary Users ◽  
Idle State ◽  
Modeling And Analysis ◽  
Interference Modeling ◽  
Primary Users

Cognitive radio networks (CRNs) have received considerable attention and viewed as a promising paradigm for future wireless networking. Its major difference from the traditional wireless networks is that secondary users are allowed to access the channel if they pose no harmful interference to primary users. This distinct feature of CRNs has raised an essential and challenging question, i.e., how to accurately estimate interference to the primary users from the secondary users? In addition, spectrum sensing plays a critical role in CRNs. Secondary users have to sense the channel before they transmit. A two-state sensing model is commonly used, which classifies a channel into either busy or idle state. Secondary users can only utilize a channel when it is detected to be in idle state. In this paper, we tackle the estimation of interference at the primary receiver due to concurrently active secondary users. With the spectrum sensing, secondary users are refrained from transmitting once an active user falls into their sensing range. As a result, the maximum number of simultaneously interfering secondary users is bounded, typically ranging from 1 to 4. This significant conclusion considerably simplifies interference modeling in CRNs. The authors present all the cases with possible simultaneously interfering secondary users. Moreover, the authors derive the probability for each case. Extensive simulations are conducted and results validate the effectiveness and accuracy of the proposed approach.

scholarly journals Exact Outage Analysis in Cognitive Two-Way Relay Networks With Opportunistic Relay Selection Under Primary User's Interference

2015 ◽  
Vol 64 (6) ◽  
pp. 2502-2511 ◽  
Author(s):  
Xing Zhang ◽  
Zhenhai Zhang ◽  
Jia Xing ◽  
Rong Yu ◽  
Pengwei Zhang ◽  
...  
Keyword(s):  
Relay Selection ◽  
Relay Networks ◽  
Opportunistic Relay Selection ◽  
Outage Analysis
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