Research On The Success Transmission Probability Of Hierarchical Heterogeneous Wireless Networks

With the rapid development of emerging businesses such as intelligent terminals and multimedia, wireless data traffic shows a trend of explosive growth, which puts forward higher requirements in terms of data rate and quality of coverage of the wireless communication networks. Through the way of hierarchical heterogeneous wireless networks where different types of low power nodes (LPNs) can be deployed within the seamless coverage of the conventional macro base stations (MBSs), network performance can be improved. In order to maximize the efficiency of spectrum, the MBSs and the LPNs share the same frequency, and this will lead to serious co-channel interference, which becomes one of the major bottlenecks in the improvement of the network performance. Therefore, in order to effectively optimize the performance of the hierarchical heterogeneous networks, it is indispensable to capture the interference characteristics of the heterogeneous network. That is to say, the interference should be analytically modeled, and the corresponding technology should be considered. Also it is a hot research topic in the wireless academic community. This thesis focuses on the interference characteristics and the performance of hierarchical heterogeneous networks, taking the network characteristics, including topology and fading, as well as the networking techniques, such as multiple antennas, cell association and user scheduling into account. The main contributions are listed as follows:The success transmission probability of signal antenna in hierarchical heterogeneous wireless networks in Nakagami fading channels was investigated. Based on the general Nakagami fading model, spatial poisson point process (PPP) was used to model the spatial distributions of nodes in heterogeneous network. The distribution of signal to interference plus noise (SINR) of each tiers and the success transmission probability of the network were derived with the use of theory of probability and random geometric mathematical tools.Performance Analysis of hierarchical heterogeneous wireless networks based on spatial interference coordination was presented. Different from traditional zero-forced beamforming, a spatial interference coordination scheme was proposed in order to eliminate the inter-tier interference in the downlink heterogeneous network. The system performances in terms of SINR, success transmission probability and area spectral efficiency were analyzed. Also the impact of the antenna number to the performance of the proposed spatial interference coordination scheme and the trade-off between multiplexing and spatial interference coordination with the spatial degrees of freedom were investigated.Research on the service success probability based on cell association and user scheduling was presented. Considering of random BS load, biased cell association and user scheduling, the service success probability of the network was evaluated with the multiple antenna technology under the proposed hierarchical heterogeneous network. The impacts of node density, antenna number and bias factor to the network performance were shown through the simulation results.