Interference Alignment Based Resource Management in MIMO Cognitive Radio Systems

Konferenz: European Wireless 2014 - 20th European Wireless Conference
14.05.2014 - 16.05.2014 in Barcelona, Spain

Tagungsband: European Wireless 2014

Seiten: 6Sprache: EnglischTyp: PDF

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Mohammed El-Absi; Kaiser, Thomas (Institute of Digital Signal Processing, Duisburg-Essen University, Germany)
Shaat, Musbah (Centre Tecnologic de Telecomunicacions de Catalunya (CTTC), Spain)
Bader, Faouzi (SUPELEC, Rennes, France)

In this paper, interference alignment (IA) is utilized to obtain an efficient and fair resource allocation algorithm in MIMO cognitive radio (CR) systems. In the proposed algorithm, IA enables all secondary users to share the available spectrum without affecting the quality-of-service of the primary system. The considered methodology increases the total degrees-of-freedom of the CR systems and achieves fairness among CR users. An optimal power allocation based on IA is formulated in order to maximize the total sum-rate while keeping the interference introduced to the primary system lower than the prescribed interference threshold. Furthermore, a sub-optimal power allocation scheme is proposed to overcome the high computational complexity of the optimal scheme. Simulations reveal that IA technique achieves significant sum-rate increase of CR systems compared to frequency division multiple access (FDMA) CR systems. Moreover, the sub-optimal algorithm approaches the optimal sum-rate performance.