This paper proposes a radio propagation prediction method that uses point cloud data based on a hybrid of the ray-tracing (RT) method and an effective roughness (ER) model in urban environments for the fifth generation mobile communications system using high frequency bands. The proposed prediction method incorporates propagation characteristics that consider diffuse scattering from surface irregularities. The validity of the proposed method is confirmed by comparisons of measurement and prediction results gained from the proposed method and a conventional RT method based on power delay and angular profiles. From predictions based on the power delay and angular profiles, we find that the proposed method, assuming the roughness of σh=1mm, accurately predicts the propagation characteristics in the 20GHz band for urban line-of-sight environments. The prediction error for the delay spread is 2.1ns to 9.7ns in an urban environment.

Network function virtualization improves the flexibility of infrastructure resource allocation but the application of commodity facilities arouses new challenges for systematic reliability. To meet the carrier-class reliability demanded from the 5G mobile core, several studies have tackled backup schemes for the virtual network function deployment. However, the existing backup schemes usually sacrifice the efficiency of resource allocation and prevent the sharing of infrastructure resources. To solve the dilemma of balancing the high level demands of reliability and resource allocation in mobile networks, this paper proposes an approach for the problem of pooling deployment of virtualized network functions in virtual EPC network. First, taking pooling of VNFs into account, we design a virtual network topology for virtual EPC. Second, a node-splitting algorithm is proposed to make best use of substrate network resources. Finally, we realize the dynamic adjustment of pooling across different domains. Compared to the conventional virtual topology design and mapping method (JTDM), this approach can achieve fine-grained management and overall scheduling of node resources; guarantee systematic reliability and optimize global view of network. It is proven by a network topology instance provided by SNDlib that the approach can reduce total resource cost of the virtual network and increase the ratio of request acceptance while satisfy the high-demand reliability of the system.

In this paper, the recent advances in cooperative distributed antenna transmission (CDAT) are introduced for spatial diversity and multi-user spatial multiplexing in 5G mobile communications network. CDAT is an advanced version of the coordinated multi-point (CoMP) transmission. Space-time block coded transmit diversity (STBC-TD) for spatial diversity and minimum mean square error filtering combined with singular value decomposition (MMSE-SVD) for multi-user spatial multiplexing are described under the presence of co-channel interference from adjacent macro-cells. Blind selected mapping (blind SLM) which requires no side information transmission is introduced in order to suppress the increased peak-to-average signal power ratio (PAPR) of the transmit signals when CDAT is applied. Some computer simulation results are presented to confirm the effectiveness of CDAT techniques.

5G is the next step in the evolution of mobile communication and a key component of the future networked society. It will include the evolution of LTE as well as new non-backwards-compatible technology. With capabilities such as massive system capacity, higher data rates, very low latency and ultra-high reliability, 5G will provide significantly enhanced mobile-broadband experience but also support a wide range of new wireless applications and use cases. Key technology components include operation at higher frequency bands and flexible spectrum usage, advanced multi-antenna/multi-site transmission, lean transmission, access/backhaul integration, and possibility for direct device-to-device communication.