Research Article
Achievable Rate of Multi-relay Cognitive Radio MIMO Channel with Space Alignment
@INPROCEEDINGS{10.1007/978-3-319-24540-9_2, author={Lokman Sboui and Hakim Ghazzai and Zouheir Rezki and Mohamed-Slim Alouini}, title={Achievable Rate of Multi-relay Cognitive Radio MIMO Channel with Space Alignment}, proceedings={Cognitive Radio Oriented Wireless Networks. 10th International Conference, CROWNCOM 2015, Doha, Qatar, April 21--23, 2015, Revised Selected Papers}, proceedings_a={CROWNCOM}, year={2015}, month={10}, keywords={Underlay cognitive radio MIMO space alignment Amplify-and-forward multiple-relay}, doi={10.1007/978-3-319-24540-9_2} }- Lokman Sboui
Hakim Ghazzai
Zouheir Rezki
Mohamed-Slim Alouini
Year: 2015
Achievable Rate of Multi-relay Cognitive Radio MIMO Channel with Space Alignment
CROWNCOM
Springer
DOI: 10.1007/978-3-319-24540-9_2
Abstract
We study the impact of multiple relays on the primary user (PU) and secondary user (SU) rates of underlay MIMO cognitive radio. Both users exploit amplify-and-forward relays to communicate with the destination. A space alignment technique and a special linear precoding and decoding scheme are applied to allow the SU to use the resulting free eigenmodes. In addition, the SU can communicate over the used eigenmodes under the condition of respecting an interference constraint tolerated by the PU. At the destination, a successive interference cancellation (SIC) is performed to estimate the secondary signal. We present the explicit expressions of the optimal PU and SU powers that maximize their achievable rates. In the numerical results, we show that our scheme provides cognitive rate gain even in absence of tolerated interference. In addition, we show that increasing the number of relays enhances the PU and SU rates at low power regime and/or when the relays power is sufficiently high.
