Generalized degrees of freedom and approximate characterization of the capacity region of the interfering multiple-access channel with feedback

在现代无线通信系统中，存在将信息从接收器传输到发射器的可能性，这称为反馈。在这个计划中的项目中，研究了反馈对蜂窝系统中的典型场景(以下称为干扰多址信道(IMAC))的影响。既要考虑确定性模型，也要考虑高斯模型。该项目的目标是根据IMAC的可实现速率区域来表征性能的基本极限。为此，信息论和信号处理的新方法和工具被应用、发展和结合，这证明了对反馈系统研究中长期悬而未决的问题的重新审视。在这些新工具中，人们可以命名确定性模型，而非对称信令和干扰对齐是用于表征/增加网络频谱效率的新方法。信息论观点应揭示，在什么条件下，通过考虑带宽限制和信号处理方面的必要努力，可以实现数据速率方面的净反馈增益。计划中的调查将以一个具体的例子为动力，该例子清楚地表明，通过反馈可以显著提高绩效。

In modern wireless communication systems, there exists the possibility of transferring information from the receivers to the transmitters which is referred to as feedback. In this planned project, the impact of feedback on a typical scenario in cellular systems, denoted henceforth as the interfering multiple access channel (IMAC), is studied. Both deterministic and Gaussian models are to be considered. The objective of the project is the characterization of fundamental limits of performance in terms of achievable rate regions for the IMAC. To this end, new methods and tools from information theory and signal processing are applied, developed, and combined, which justify a renewed examination of longstanding open problems in the research on feedback systems. Among these new tools one can name the deterministic model, while asymmetric signaling and interference alignment are new methods which are used to characterize/increase the spectral efficiency of a network. The information theoretic perspective shall reveal, under which conditions a net feedback gain in terms of data rate can be achieved by taking into account bandwidth constraints and the necessary effort in terms of signal processing. The planned investigation will be motivated by a concrete example, which clearly shows that significant performance improvement can be obtained from feedback.