Modern 5G wireless cellular networks use massive multiple-input multiple-output (MIMO) technology. This concept entails using an antenna array at a base station to concurrently service many mobile devices that have several antennas on their side. In this field, a significant role is played by the precoding (beamforming) problem. During downlink, an important part of precoding is the power allocation problem that distributes power between transmitted symbols. In this paper, we consider the power allocation problem for a class of precodings that asymptotically work as regularized zero-forcing. Under some realistic assumptions, we simplify the sum spectral efficiency functional and obtain tractable expressions for it. We prove that equal power allocation provides optimum for the simplified functional with total power constraint (TPC). Also, low-complexity algorithms that improve equal power allocation in the case of per-antenna power constraints (PAPC) are proposed. On simulations using Quadriga, the proposed algorithms show a significant gain in sum spectral efficiency while using a similar computing time as the reference solutions.
翻译:现代 5G 无线蜂窝网络使用大规模多投入多输出技术。 这一概念意味着在基地站使用天线阵列, 以同时服务许多有多个天线的移动设备。 在这一领域, 预编码( 光谱化)问题起着重要作用 。 在下行链接中, 预编码的一个重要部分是传输符号之间分配权力的权力分配问题 。 在本文中, 我们考虑的是某类预编码的动力分配问题, 这些预编码是正常化的零力。 根据一些现实的假设, 我们简化总光谱效率功能, 并获得可移植的表达方式 。 我们证明, 等量的电力分配为简化功能提供了最佳的最好条件, 再加上总功率限制( TPC TPC ) 。 另外, 提议了低兼容性算法, 改进对单安纳功率限制( PaPC) 的同等权力分配。 在使用 Quadriga 的模拟中, 拟议的算法显示在使用类似计算时间作为参考解决方案的情况下, 光谱效率的显著增加。