Performance Comparison between Adaptive and Fixed Transmit Power in Underlay Cognitive Radio Networks

Abstract

Abstract-In this paper, we compare the performance in terms of symbol error probability, data rate and power consumption of the use of fixed transmit power (FTP) and adaptive transmit power (ATP) in underlay cognitive radio networks. The use of FTP alleviates the signaling requirements of underlay cognitive radio networks compared to the ATP. Nevertheless, the use of FTP influences the performances of the underlay cognitive radio networks. To study this influence, we consider three relay selection schemes using FTP: opportunistic decode and forward with FTP (O-DF with FTP), opportunistic amplify and forward with FTP (O-AF with FTP) and partial relay selection with FTP (PR with FTP). We compare the performances of these schemes in terms of symbol error probability, data rate and power consumption with three relay selection schemes using ATP: opportunistic decode and forward with ATP (O-DF with ATP), opportunistic amplify and forward with ATP (O-AF with ATP) and partial relay selection with ATP (PR with ATP). We provide exact and/or lower bound expressions of the symbol error probabilities of O-DF, O-AF and PR with FTP. The analytical study for the data rate and the power consumption is also provided. Our comparison study shows that FTP has a positive impact on the data rate and power consumption performance while it deteriorates the symbol error probability performance.Index Terms-Cognitive radio, relaying, fixed transmit power, adaptive transmit power, symbol error probability, data rate, power consumption.

Outage probability analysis of optimal and suboptimal interference aware routing protocols for multihop underlay cognitive radio networks

“…Note that in that case, we have to replace the SNR at relays by signal‐to‐interference‐plus‐noise ratio, which is no longer exponentially distributed, and outage probability computation is not straightforward. Some preliminary results dealing with lower bounds of the symbol error probability in the presence of mutual interference are provided for dual‐hop relaying in . We can say that the derived results in this paper are lower bounds and that the outage probability will be higher in the presence of interference from PT to the relays.…”

Performance Analysis of Cognitive Cooperative Communication System Based on Optimal Relay Selection Scheme

“…2 and Fig. 3 [15]. Let S be the dedicated centralized node that is responsible for collecting, sensing the CSI and selecting the relays.…”

“…For example, it may be a sensor node to measure some data and transmit it to a certain collection point and its processing power is limited by its battery life. In [15] and [16], several relaying schemes were investigated where secondary transmitters (source and relay) use their maximum available power when the primary interference constraint is verified and remain silent otherwise. The authors in [15] and [16] only considered single primary user close to the secondary system.…”

Performance Evaluation of Relay Selection Schemes in Beacon-Assisted Dual-hop Cognitive Radio Wireless Sensor Networks under Impact of Hardware Noises

“…However, in [35], the authors proposed a new PRS scheme, where the relay is selected by using CSIs of the relay-destination links. In [35][36][37][38][39][40], different relay selection schemes in underlay CR networks were reported. Particularly, the authors in [35][36][37] evaluated the performance of the PRS protocols in terms of bit error rate (BER) and outage probability (OP).…”

“…Particularly, the authors in [35][36][37] evaluated the performance of the PRS protocols in terms of bit error rate (BER) and outage probability (OP). In [37][38][39], the cooperative cognitive schemes using the ORS methods were proposed and analyzed.…”