[论文解读] Fundamental Limits of Communications in Interference Networks-Part I: Basic Structures

Reza Khosravi-Farsani, Farokh Marvasti|arXiv (Cornell University)|Jul 12, 2012

Wireless Communication Security Techniques参考文献 52被引用 11

一句话总结

本文通过将多址接入信道（MAC）、广播信道（BC）、经典干扰信道（CIC）和认知无线电信道（CRC）识别为核心构建模块，建立了一个统一框架，用于分析干扰网络中的基本通信极限。该文采用统一方法推导出新的外 bound，证明了在混合干扰和噪声干扰场景下离散 CIC 的和速率容量，并对一类更强大 CRC 实现了容量区域的完整表征，即使在输入依赖和接收端辅信息条件下也成立。

ABSTRACT

In these series of multi-part papers, a systematic study of fundamental limits of communications in interference networks is established. Here, interference network is referred to as a general single-hop communication scenario with arbitrary number of transmitters and receivers, and also arbitrary distribution of messages among transmitters and receivers. It is shown that the information flow in such networks follows similar derivations from many aspects. This systematic study is launched by considering the basic building blocks in Part I. The Multiple Access Channel (MAC), the Broadcast Channel (BC), the Classical Interference Channel (CIC) and the Cognitive Radio Channel (CRC) are proposed as the main building blocks for all interference networks. First, a brief review of existing results regarding these basic structures is presented. New observations are also presented in this regard. Specifically, it is shown that the well-known strong interference conditions for the two-user CIC do not change if the inputs are dependent. Next, new capacity outer bounds are established for the basic structures with two receivers. These outer bounds are all derived based on a unified framework. By using the derived outer bounds, some new capacity results are proved for the CIC and the CRC; a mixed interference regime is identified for the two-user discrete CIC where the sum-rate capacity is established. Also, a noisy interference regime is derived for the one-sided discrete CIC. For the CRC, a full characterization of the capacity region for a class of more-capable channels is obtained. Moreover, it is shown that the derived outer bounds are useful to study the channels with one-sided receiver side information wherein one of the receivers has access to the non-intended message; capacity bounds are also discussed in details for such scenarios.

研究动机与目标

• 识别并形式化用于分析干扰网络的基本构建模块——MAC、BC、CIC 和 CRC。
• 通过推导容量外 bound 的通用框架，统一分析干扰网络。
• 研究输入依赖性和接收端辅信息对干扰信道容量的影响。
• 在新外 bound 框架下，表征特定类别的干扰信道和认知无线电信道的容量区域。
• 识别新型干扰场景——混合与噪声干扰，其中和速率容量被完全表征。

提出的方法

• 提出一种统一框架，用于推导具有两个接收端的干扰网络容量的外 bound。
• 将统一框架应用于推导 MAC、BC、CIC 和 CRC 结构的新外 bound。
• 利用推导出的外 bound，证明在混合干扰场景下两用户离散 CIC 的和速率容量。
• 为单边离散 CIC 识别出一个噪声干扰场景，其中在特定条件下实现了容量表征。
• 在推导出的 bound 框架下，实现对一类更强大 CRC 的完整容量区域表征。
• 分析具有单边接收端辅信息的信道，其中一接收端观测到非期望信号，推导容量 bound。

实验结果

研究问题

• RQ1 当输入依赖时，两用户 CIC 中的强干扰条件如何变化？
• RQ2 是否可以将统一的外 bound 框架应用于推导基本干扰网络结构的容量极限？
• RQ3 哪些干扰场景（如混合或噪声干扰）允许对离散 CIC 实现完全的和速率容量表征？
• RQ4 在所提框架下，对一类更强大信道的 CRC 容量区域是什么？
• RQ5 接收端对非期望信号的辅信息如何影响干扰网络中的容量 bound？

主要发现

• 即使在输入依赖的情况下，两用户经典干扰信道的强干扰条件保持不变。
• 建立了一个新的外 bound 框架，可实现对 MAC、BC、CIC 和 CRC 结构的容量结果推导。
• 对于两用户离散 CIC，识别出一个混合干扰场景，其中和速率容量被完全表征。
• 为单边离散 CIC 推导出一个噪声干扰场景，其中在特定条件下确立了和速率容量。
• 利用推导出的外 bound，对一类更强大信道的 CRC 实现了容量区域的完全表征。
• 外 bound 被证明在分析具有单边接收端辅信息的信道时有效，可在这些场景下提供紧致的容量 bound。