Multiaccess Communication via a Broadcast Approach Adapted to the Multiuser Channel
Multiaccess Communication via a Broadcast Approach Adapted to the Multiuser Channel
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DOI：
10.1109/tcomm.2018.2809733
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发表时间：
2018-08-01
影响因子：
8.3
通讯作者：
Tajer, Ali
中科院分区：
文献类型：
--
作者：
Kazemi, Samia;Tajer, Ali
介绍了一种在慢衰落信道上实现多址通信的广播策略，该策略中信道状态信息仅为接收端所知。在这种策略中，发射机将其信息流分成多个独立的信息流，每个信息流适合于特定的实际信道实现。所提出的策略和现有的主要区别是，在现有的方法中，每个发射机适应其传输策略只对接收机的直接信道的衰落过程，因此，直接采用单用户策略先前设计的单用户信道。然而，每个用户对网络范围度量的贡献（例如，总速率容量）不仅取决于用户到接收机的直接信道，而且还取决于其它信道的质量。在此前提下，本文提出了一种替代的广播策略，其中发射机调整其传输的组合状态产生的所有用户的信道。这导致每个发射机生成更大数量的信息流，并且接收机采用不同的解码策略。建立了一个可实现的速率区域和一个捕获不同信息层速率之间的折衷的外边界，并且示出了可实现的速率区域包含了基于将广播方法适应于单用户信道而获得的现有已知容量区域。
A broadcast strategy for multiple access communication over slowly fading channels is introduced, in which the channel state information is known to only the receiver. In this strategy, the transmitters split their information streams into multiple independent information streams, each adapted to a specific actual channel realization. The major distinction between the proposed strategy and the existing ones is that in the existing approaches, each transmitter adapts its transmission strategy only to the fading process of its direct channel to the receiver, hence, directly adopting a single-user strategy previously designed for the single-user channels. However, the contribution of each user to a network-wide measure (e.g., sum-rate capacity) depends not only on the user's direct channel to the receiver, but also on the qualities of other channels. Driven by this premise, this paper proposes an alternative broadcast strategy in which the transmitters adapt their transmissions to the combined states resulting from all users' channels. This leads to generating a larger number of information streams by each transmitter and adopting a different decoding strategy by the receiver. An achievable rate region and an outer bound that capture the tradeoff among the rates of different information layers are established, and it is shown that the achievable rate region subsumes the existing known capacity regions obtained based on adapting the broadcast approach to the single-user channels.