毫米波MIMO系统基于块对角化的混合预编码算法

在毫米波大规模多输入多输出(multiple-input multiple-output， MIMO)系统中，传统的数字预编码器需要给每一个天线配置一条独立的射频(radio frequency， RF)链路，这将会大大增加系统的成本和功耗，通过混合预编码可以有效地解决射频链路受限的问题。目前，混合预编码的研究大多都是针对多用户单天线场景，没有考虑到用户端配置多根天线的情况，为了消除多用户间干扰，增加系统的频谱效率，提出一种针对多用户多天线场景的混合预编码算法。在模拟端，通过基于矩阵迭代算法和模拟矩阵集合设计方法进行求解。在基带端，采用块对角化技术(block diagonalization，BD)消除多用户之间的干扰。仿真结果表明，所提出的多用户混合预编码算法相较于传统的块对角化混合预编码算法具有更好的性能表现，且更接近于纯数字预编码算法。

Hybrid precoding algorithm based on block diagonalization for millimeter wave MIMO systems

In millimeter-wave large-scale multiple-input multiple-output (MIMO) systems, traditional digital precoders need to be configured with an independent radio frequency (RF) link for each antenna. The cost and power consumption of the system are greatly increased, and the problem of limited RF link can be effectively solved by the hybrid precoding. At present, most of the research on hybrid precoding is carried out in a multi-user single-antenna scenario. It does not take into account the situation where multiple antennas are configured at the user end. In order to eliminate inter-user interference and increase the spectrum efficiency of the system, this paper proposes a hybrid precoding algorithm for multi-user multi-antenna scenarios. On the simulation side, the solution is solved by a matrix iterative algorithm and an analog matrix set design method. At the baseband end, block diagonalization(BD) is used to eliminate interference between multiple users. The simulation results show that the multi-user hybrid precoding algorithm proposed in this paper has better performance than the traditional block diagonal hybrid precoding algorithm, and is closer to the pure digital precoding algorithm.