Research On Interference Management Technology Of Wireless Communication Network

Interference management is of critical importance in communication net-works due to its great potential in improving the efficiency and reliability of wireless transmissions. With the proliferation of smart devices and explo-sive demands of wireless data traffic, the physical scarcity of spectrum re-sources and the hyper densification of network deployment impose new chal-lenges for the next generation wireless networks. Interference management provides an effective way of solving the above technical difficulties. Cognitive radio networks and MIMO cellular networks are considered as two important paradigms of future wireless networks. In this dissertation, by applying tools from stochastic geometry and information theory, the interference management schemes in large-scale cognitive radio networks and MIMO cellular networks are developed and analyzed.Firstly, two threshold-based interference management schemes are pro-posed for large-scale cognitive radio networks to constrain the cross-interference from the secondary transmitters to the primary receivers. By ap-plying tools from stochastic geometry, the spatial opportunity of cognitive ra-dio networks is analyzed, and the conditional distribution of the active sec-ondary/primary transmitters given a typical primary/secondary receiver at the origin is investigated. With the obtained spatial opportunity and the conditional distribution of the active secondary/primary transmitters, the coverage proba-bilities as well as the spatial throughputs of the primary and secondary net-works under the proposed threshold-based interference management schemes are characterized.Secondly, for large-scale cognitive radio networks, we further propose t-wo carrier sensing based interference management schemes to not only prevent the secondary transmitters from causing harmful interference at the primary receivers but also try to avoid collisions among the concurrent secondary trans-missions. By applying tools from stochastic geometry, the transmission oppor-tunity of the secondary transmitters is analyzed. We then characterize the con-ditional distribution of the active secondary/primary transmitters givn a typical primary/secondary receiver at the origin. With the obtained transmission op-portunity and the conditional distribution of the active secondary/primary trans-mitters, we finally evaluate the coverage probabilities and the spatial through-puts of the primary and secondary networks under the proposed carrier sensing based interference management schemes.Lastly, we characterize the spatially-normalized degrees of freedom of a two-cell, K=3users per cell MIMO cellular networks with M antennas at each user and N antennas at each base-station. Based on the obtained spatially-normalized degrees of freedom values, we address the issue of redundant spa-tial dimensions at the transmitters, receivers, both or neither, investigate the degrees of freedom benefit of MIMO processing, and completely settle the problem of feasibility of linear interference alignment, all under the scenari-o of two-cell M×N MIMO cellular networks with K=3users per cell.