In order to achieve terabits-per-second (Tbps) data rates in the sixth-generation (6G) mobile system, wireless communications are required to exploit the abundant spectrum in the millimeter-wave (mmWave) and terahertz (THz) bands. However, high-frequency transmission heavily relies on high beamforming gain to compensate for severe propagation loss. A beam-based system faces a barrier in the process of initial access, where a base station must broadcast synchronization signals and system information to all users within its coverage. Hence, this paper proposes a novel omnidirectional broadcasting scheme for mmWave and THz systems with hybrid beamforming. It provides an instantaneously equal gain over all directions by forming complementary beams over sub-arrays. Numerical results verify that it can achieve omnidirectional coverage with a performance that remarkably outperforms the previous scheme.

翻译：为了在第六代(6G)移动系统中实现千兆赫/秒(Tbps)数据率,需要无线通信来利用毫米波(mmWave)和泰赫兹(THz)波段的丰富频谱,然而,高频传播严重依赖高波束增益来弥补严重的传播损失。以波束为基础的系统在初始访问过程中面临一个障碍,基地台必须在其覆盖范围内向所有用户广播同步信号和系统信息。因此,本文件提议为MmmWave和THz系统提供一个新的全方位直接广播计划,通过在次阵列上形成互补的波束,在所有方向上提供即时等增益。数字结果证实,它能够实现全线覆盖,其性能明显超过前一个方案。