Decentralized Beamformer Design with Limited Multi-Cell Cooperation for Interference Channel of Cognitive Radio Networks
Decentralized Beamformer Design with Limited Multi-Cell Cooperation for Interference Channel of Cognitive Radio Networks
复制标题
DOI：
10.1109/twc.2013.071913.121996
复制
发表时间：
2013-07
影响因子：
10.4
通讯作者：
Young-Jin Kim;Moon-Gun Song;Yong-Sang Cho;G. Im
中科院分区：
文献类型：
--
作者：
Young-Jin Kim;Moon-Gun Song;Yong-Sang Cho;G. Im
在基于频谱共享的认知无线电网络中，多个次系统可以接入许可频谱以更好地利用稀缺的无线电资源。当多个次发射机共处一地时，次用户（SU）的加权和速率主要受到小区间干扰（ICI）的限制。在有限的协作条件下，提出了一种基于对偶分解的分布式波束赋形算法。为了最大化SU的加权和速率，所提出的分散式算法有效地减轻了ICI的不希望的泄漏功率限制在每个次级发射机。由于在实际应用中，信道信息在发射端并不是完全已知的，因此我们还设计了一种分散的鲁棒波束形成器。为了有效地设计鲁棒波束形成器，一个凸问题，制定了半定松弛。仿真结果表明，该算法在具有理想信道状态信息（P-CSI）的情况下，通过限制非期望的泄漏功率，有效地最大化了加权和速率性能。对于具有小误差界的不完美CSI，所提出的鲁棒波束形成器接近P-CSI情况下的性能，而不会对主用户造成有害干扰。
In spectrum-sharing-based cognitive radio networks, multiple secondary systems can access a licensed spectrum to better utilize scarce radio resources. When the multiple secondary transmitters are co-located, the weighted sum-rate of the secondary users (SUs) is mainly limited by the inter-cell interference (ICI). With limited cooperation among co-located secondary transmitters, we propose an algorithm for decentralized beamforming with power allocation via dual decomposition. To maximize the weighted sum-rate of the SUs, the proposed decentralized algorithm efficiently mitigates the ICI by the undesired leakage power limitation at each secondary transmitter. Because the channel information is not perfectly known at the transmitter in practical applications, we also develop a decentralized robust beamformer. To efficiently design the robust beamformer, a convex problem is formulated by semi-definite relaxation. Simulation results show that the proposed algorithm with perfect channel state information (P-CSI) efficiently maximizes the weighted sum-rate performance by the undesired leakage power limitation. For an imperfect CSI with a small error bound, the proposed robust beamformer approaches the performance of a P-CSI case, without causing harmful interference to the primary user.