蜂窝网络中D2D通信的干扰控制技术研究

The device-to-device (D2D) communication, which allows two users in close proximity to communicate directly under the control of cellular wireless network， improves the spectral efficiency and the mobile network coverage owing to resource reuse, and represents a new challenge to both interference controlling and resource scheduling for wireless communication network at the same time. Firstly, in the D2D communication system modeled on the basis of the reuse of cellular resources, a maximizing the system throughput problem is brought forward to optimize the system performance and provide guidance on resource scheduling and reusing strategies. Secondly, the channels statistical characteristics of the cellular users and the D2D links are investigated to derive the achievable ergodic rates of the cellular users and the D2D links expressed in terms of closed forms. Using the results of the investigation, we propose adaptive interference suppression schemes under the impact of the imperfect factors existing in the actual system. Further by considering he full advantages of 3-dimension characteristics of the actual world MIMO channel, the asymptotic characteristics of the achievable rate of the system are analyzed. Along with the emerging of the massive MIMO technology, the adaptive 3-dimension beam-forming scheme will be researched to enhance the performance gains of interference cancellation by exploiting the extra degrees of freedom in the elevation. We believe that the outcomes of this project will provide new theoretical results for the investigation on resource sharing design and interference control, and also support the applications of these techniques in future wireless communication system.

在蜂窝无线通信网络的控制下，邻近用户间建立D2D通信连接，通过无线资源复用提高频谱的空间复用效率，在优化网络覆盖的同时，对无线网络的干扰控制和资源调度也提出了新的挑战。首先，建构直通通信共享无线资源的通信系统模型，提出一个最大化系统速率问题优化系统性能，指导多用户D2D系统的资源调度和复用策略。然后，分析小区用户和D2D用户的信道统计特性，推导出传统波束成形策略进行干扰控制时可达速率的闭式表达式，在实际系统中存在的非理想因素影响下，提出自适应的干扰抑制方案。最后，利用实际MIMO系统无线信道的3D空间特性，在大规模天线技术发展的背景下，分析系统容量的渐近特性，提出自适应的三维波束成形策略，利用垂直维度空间自由度，增强D2D技术中干扰抑制的效果。研究成果将为未来无线通信系统中的资源共享和干扰控制技术研究提供理论和技术支撑。

在蜂窝无线通信网络中引入频谱资源共享的直通D2D通信技术，提高系统频谱效率的同时，也引入了对蜂窝用户通信的干扰。我们的目标是在为蜂窝用户提供服务质量保证的同时，提升D2D链路的性能，基于此，提出了若干棘手的资源共享问题。首先，从干扰抑制的角度出发，提高D2D通信系统频谱效率，联合优化了多用户D2D通信系统容量。我们还发现利用D2D链路对蜂窝用户的干扰，可增强蜂窝用户通信的安全性。在功率受限的约束条件下，优化系统资源共享的效用，提高系统频谱效率、安全性等系统性能。然后，提出了若干有效功率控制策略，优化D2D通信的能量效率。我们还分析了D2D系统资源共享的理论性能，诸如信道容量，可达速率等。在无线通信系统频谱资源有限，功率资源有限等约束条件下，本课题通过适当的干扰控制策略，既保证蜂窝用户的服务质量需求，又优化了D2D链路的性能。