On the Spectral Efficiency of Full-Duplex Small Cell Wireless Systems
On the Spectral Efficiency of Full-Duplex Small Cell Wireless Systems
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DOI：
10.1109/twc.2014.2334610
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发表时间：
2014-09-01
影响因子：
10.4
通讯作者：
Latva-aho, Matti
中科院分区：
文献类型：
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作者：
Dan Nguyen;Le-Nam Tran;Latva-aho, Matti
我们研究了全双工小小区无线系统的频谱效率，其中具有全双工能力的基站（BS）被设计为在相同的系统资源上向/从多个半双工用户发送/接收数据。设计这样的系统的主要障碍是由于BS处的自干扰和用户之间的同信道干扰。因此，我们考虑一个联合波束形成器的设计，以最大限度地提高频谱效率受到一定的功率约束。首先将设计问题转化为秩约束优化问题，然后应用秩松弛法。然而，放松的问题仍然是非凸的，因此，很难找到最优解。在这里，我们提出了两个可证明收敛的算法，以获得次优解。基于Frank-Wolfe算法的概念，在第一个算法的每次迭代中，我们通过行列式最大化程序来近似设计问题。第二种方法是建立在序贯参数凸逼近方法，它允许我们将放松的问题转化为一个半定规划在每次迭代。在小小区设置下的大量数值实验表明，与半双工系统相比，采用所提出的算法的全双工系统可以实现大的增益。
We investigate the spectral efficiency of full-duplex small cell wireless systems, in which a full-duplex capable base station (BS) is designed to send/receive data to/from multiple half-duplex users on the same system resources. The major hurdle for designing such systems is due to the self-interference at the BS and co-channel interference among users. Hence, we consider a joint beamformer design to maximize the spectral efficiency subject to certain power constraints. The design problem is first formulated as a rank-constrained optimization problem, and the rank relaxation method is then applied. However, the relaxed problem is still nonconvex, and thus, optimal solutions are hard to find. Herein, we propose two provably convergent algorithms to obtain suboptimal solutions. Based on the concept of the Frank-Wolfe algorithm, we approximate the design problem by a determinant maximization program in each iteration of the first algorithm. The second method is built upon the sequential parametric convex approximation method, which allows us to transform the relaxed problem into a semidefinite program in each iteration. Extensive numerical experiments under small cell setups illustrate that the full-duplex system with the proposed algorithms can achieve a large gain over the half-duplex system.