Time-Division Multiuser MIMO with Statistical Feedback
Time-Division Multiuser MIMO with Statistical Feedback
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DOI：
10.1155/2008/632134
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发表时间：
2008
影响因子：
1.9
通讯作者：
Kai‐Kit Wong;Jia Chen
中科院分区：
文献类型：
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作者：
Kai‐Kit Wong;Jia Chen
本文研究了在块平坦衰落条件下的时分多用户多输入多输出（MIMO）天线系统，该系统对用户进行了单独的中断率概率约束，并且在任意时隙（或块）只有一个用户访问信道。假设有一个下行信道，发射机只知道信道的统计信息，我们的目标是通过联合优化用户的功率分配和分时（即时隙数），使总发射功率最小，以实现用户的停电约束。本文首先推导出所谓的最小功率方程（MPE），求解在给定块数的情况下，单用户MIMO块衰落信道达到给定中断率概率所需的最小发射功率。然后构造一个凸优化问题，该问题可以模拟原问题结构，并允许联合考虑用户的功耗和概率约束，从而给出次优的多用户分时解。最后与MPE结合，为时分多用户MIMO系统提供联合功率分配和分时解决方案。数值结果表明，该方案与全局最优方案的性能基本一致，差异不大。
This paper investigates a time-division multiuser multiple-input multiple-output (MIMO) antenna system in -block flat fading where users are given individual outage rate probability constraints and only one user accesses the channel at any given time slot (or block). Assuming a downlink channel and that the transmitter knows only the statistical information about the channel, our aim is to minimize the overall transmit power for achieving the users' outage constraint by jointly optimizing the power allocation and the time-sharing (i.e., the number of time slots) of the users. This paper first derives the so-called minimum power equation (MPE) to solve for the minimum transmit power required for attaining a given outage rate probability of a single-user MIMO block-fading channel if the number of blocks is predetermined. We then construct a convex optimization problem, which can mimic the original problem structure and permits to jointly consider the power consumption and the probability constraints of the users, to give a suboptimal multiuser time-sharing solution. This is finally combined with the MPE to provide a joint power allocation and time-sharing solution for the time-division multiuser MIMO system. Numerical results demonstrate that the proposed scheme performs nearly the same as the global optimum with inappreciable difference.