Open AccessEnergy‐efficient cooperative two‐hop amplify‐and‐forward relay protocol in cognitive radio networks
Author(s) -
Cai Caixia,
Qiu Runhe
Publication year - 2016
Publication title -
iet communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.355
H-Index - 62
eISSN - 1751-8636
pISSN - 1751-8628
DOI - 10.1049/iet-com.2016.0058
Subject(s) - relay , computer science , transmission (telecommunications) , computer network , telecommunications link , node (physics) , bit error rate , antenna diversity , cognitive radio , fading , interference (communication) , wireless , channel (broadcasting) , telecommunications , engineering , power (physics) , physics , structural engineering , quantum mechanics
It has been shown that amplify‐and‐forward (AF) transmission is a viable transmission protocol for wireless networks incorporating distributed spatial diversity. However, a drawback of this relatively simple protocol is identified, the destination node is only to combine a part of the signal, while the other part of the signal has been regarded as interference for delay, leading to the lower utilisation of the resource inevitably, which manifests in the bigger noise, lower signal‐to‐noise ratio, and higher bit error rate. A revised AF relay protocol has been proposed for it could fully combine signal and eliminate delay at destination node through caching signal. A multi‐user single‐relay transmission model could demonstrate the superior performance of this protocol, which is in a hotspots region of a cognitive radio network. The closed‐form solution of the channel transmission rate is obtained with the form of matrix multiplication, and it can ensure that even if without any interference cancellation operation it still can improve the transmission rate. Analytical expression of downlink transmission energy efficiency (DLEE) has been derived. Numerical simulation results show that the transmission performances and DLEE have been improved by proposed protocol compared with the conventional AF relay protocol and direct transmission.