Coordinated Multipoint Transmission with Limited Backhaul Data Transfer
Coordinated Multipoint Transmission with Limited Backhaul Data Transfer
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DOI：
10.1109/twc.2013.050613.120825
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发表时间：
2013-05
影响因子：
10.4
通讯作者：
Jian Zhao;Tony Q. S. Quek;Z. Lei
中科院分区：
文献类型：
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作者：
Jian Zhao;Tony Q. S. Quek;Z. Lei
当联合处理技术应用于协调多点（CoMP）下行传输时，每个移动站的用户数据需要通过回程在多个基站之间共享。如果用户数量很大，这种数据交换可能导致巨大的回程信令开销。在本文中，我们考虑了一个具有多天线BSs和单天线用户的多小区CoMP网络。解决了在给定的服务质量和每个基站功率约束下，联合设计发射波束形成器和用户数据分配以最小化回程用户数据传输的问题。我们证明这个问题可以转化为一个0范数最小化问题，这是np困难的。受最近压缩感知研究结果的启发，我们提出了两种算法来解决这个问题。第一种算法是基于重加权的1-范数最小化算法，它解决了一系列凸的0-范数最小化问题。在第二种算法中，我们首先解决联合聚类和波束形成问题的l2范数松弛问题，然后迭代去除最小发射功率对应的链路。第二种算法具有更快的求解速度，并且在一定的假设下也可以半分布式的方式实现。仿真结果表明，这两种算法都能显著减少回程中用户数据的传输。
When the joint processing technique is applied in the coordinated multipoint (CoMP) downlink transmission, the user data for each mobile station needs to be shared among multiple base stations (BSs) via backhaul. If the number of users is large, this data exchange can lead to a huge backhaul signaling overhead. In this paper, we consider a multi-cell CoMP network with multi-antenna BSs and single antenna users. The problem that involves the joint design of transmit beamformers and user data allocation at BSs to minimize the backhaul user data transfer is addressed, which is subject to given quality-of-service and per-BS power constraints. We show that this problem can be cast into an ℓ0-norm minimization problem, which is NP-hard. Inspired by recent results in compressive sensing, we propose two algorithms to tackle it. The first algorithm is based on reweighted ℓ1-norm minimization, which solves a series of convex ℓ0-norm minimization problems. In the second algorithm, we first solve the ℓ2-norm relaxation of the joint clustering and beamforming problem and then iteratively remove the links that correspond to the smallest transmit power. The second algorithm enjoys a faster solution speed and can also be implemented in a semi-distributed manner under certain assumptions. Simulations show that both algorithms can significantly reduce the user data transfer in the backhaul.