| The traditional cellular system can be extended to a new generation of multi-hop cellular system with the use of wireless relay. Furthermore, as a new relay technology, network coding is able to guarantee the maximum throughput and utilize the existing network resources to the maximum extent. The new generation cellular system also needs some advanced frequency reuse technologies, such as soft frequency reuse. This paper mainly studies these two technologies.Chapter 2 introduces the related relay technologies. With the characteristics of the radio channel, this chapter focuses on the AF (Amplify and Forward) and DF (Decode and Forward) relay transmission protocol and channel capacity based on the diversity and combining technologies.Chapter 3 studies the system performance of wireless network coding based on opportunistic relay selection. The capacity performance of network coding awareness relay selection is compared with the traditional relay selection in the studied multi-hop cellular systems. Simulation results show that network coding awareness relay selection can provide up to 25% capacity gain compared to the traditional opportunistic relay selection, in addition to increased fairness among the users.Chapter 4 studies the frequency reuse techniques in the new generation cellular system. Firstly, three types of static inter-cell interference coordination techniques are described, which are hard frequency reuse, partial frequency reuse and soft frequency reuse. As a mainstream technology for LTE (Long Term Evolution) frequency planning, soft frequency reuse is discussed in detail in this chapter, which consists of its origin, the frequency reuse factor selection, the basic principle, division guidelines, as well as its advantages. Under a soft frequency reuse scheme, the cell is divided into the central region and the edge region. The two regions are defined with different reuse factor so as to improve the throughput of the cell edge region without sacrificing the overall spectrum utilization. Simulation results are the same to the theoretical results of the soft frequency reuse scheme proposed by Huawei. |
