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

点击翻译按钮获取中文摘要

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.