A multi-antenna broadcast channel scenario is considered where a base station delivers contents to cache-enabled user terminals. A joint design of coded caching (CC) and multigroup multicast beamforming is proposed to benefit from spatial multiplexing gain, improved interference management and the global CC gain, simultaneously. The developed general content delivery strategies utilize the multiantenna multicasting opportunities provided by the CC technique while optimally balancing the detrimental impact of both noise and inter-stream interference from coded messages transmitted in parallel. Flexible resource allocation schemes for CC are introduced where the multicast beamformer design and the receiver complexity are controlled by varying the size of the subset of users served during a given time interval, and the overlap among the multicast messages transmitted in parallel, indicated by parameters $\alpha $ and $\beta $ , respectively. Degrees of freedom (DoF) analysis is provided showing that the DoF only depends on $\alpha $ while it is independent of $\beta $ . The proposed schemes are shown to provide the same degrees-of-freedom at high signal-to-noise ratio (SNR) as the state-of-art methods and, in general, to perform significantly better, especially in the finite SNR regime, than several baseline schemes.

中文翻译：

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编码缓存的多天线干扰管理

考虑多天线广播信道场景，其中基站向启用缓存的用户终端传送内容。提出了编码缓存 (CC) 和多组多播波束成形的联合设计，以同时受益于空间复用增益、改进的干扰管理和全局 CC 增益。开发的通用内容交付策略利用了 CC 技术提供的多天线多播机会，同时最佳地平衡了来自并行传输的编码消息的噪声和流间干扰的不利影响。引入了针对 CC 的灵活资源分配方案，其中通过改变给定时间间隔内服务的用户子集的大小来控制多播波束形成器设计和接收器复杂性， $\alpha $ 和 $\beta $ ， 分别。提供的自由度 (DoF) 分析表明 DoF 仅取决于 $\alpha $ 虽然它独立于 $\beta $ . 所提出的方案显示出在高信噪比 (SNR) 下提供与最先进方法相同的自由度，并且一般而言，性能明显更好，尤其是在有限 SNR 范围内，比几个基线方案。