Resource Management On User Pairing:from2D To3D-MIMO Systems

With the rapid development of wideband wireless technology, in the past few decades, mobile communication system is head for wider range, high data rate, larger system capacity, multiple services and low expenditure. ITU also formally adopted the long-term evolution-advanced (LTE-A) system and802.16m technical specifications established for issues of international standards future mobile communication systems (IMT-Advanced). Multi-user MIMO (MU-MIMO), transmission through the expansion of space dimensions and exponentially increasing the channel capacity, has been widely adopted by a variety of wireless communication standards.In terms of practical application scenarios, which the channel conditions of different users varies, schemes for multi-user scheduling and resource allocation, has become the key factor to MU-MIMO system performance. Meanwhile, the complexity and feedback overhead can be the cost to many advantages that multi-user MIMO technology brings. Therefore, to achieve the tradeoff among MU-MIMO throuthput, computational complexity and feedback overhead is nessessary. In addition, at this stage MU-MIMO technology mainly use the horizontal DOF to dynamically adjust sending signals, underutilized the freedom of three-dimensional space. Therefore, the tradeoff of2D MU-MIMO and3D-MIMO pairing design are very important topics. Based on this background, this thesis focus on the system performance influence of2D and3D-MIMO user pairing in LTE-A system in on, and based on the channel state information, proposes appropriate tradeoff solution. The main contributions are described as follows:First, this thesis summarizes and evaluates several user pairing schemes in2D MU-MIMO systems. Through the system-level simulations based on the LTE R10configuration and evaluation, each user pairing scheme system performance is evaluated, the various scenarios for each algorithm are summarized for scene, and feasibility analysis is conducted.Secondly, this thesis analyzes the multi-user pairing. The three main reasons affected the overall performance of multi-user systems are:1) low SINR user pairing;2) adaptability of user rank;3) feedback overhead.In the2D scenario, through the analysis of precoding codebook, how the precoding codebook and feedback overhead impact on the system is researched. Meanwhile, the PMI&RI pairing cluster algorithms are proposed. Through simulation, we conclude that:based on the PMI&RI pairing cluster,2D MU-MIMO can achieve tradeoff between feedback overhead and system throughput.Then, this thesis further analyzes pairing schemes in3D-MIMO scenario, first the3D-MIMO channel environment characteristics are analyzed. Based on3D Channel, full dimension of3D MIMO codebook are designed. Based on the3D codebook,3D MU-MIMO users pairing algorithms are proposed. Through system-level simulation, the system performance of3D user pairing is evaluated. Complexity, feedback overhead, pairing proportion is analyzed with respects to the previous2D MU-MIMO user pairing. Simulation results show that the3D-MIMO multi-user pairing can effectively utilize vertical direction spatial degrees of freedom to improve the spectrum efficiency.Finally, a brief summary of this thesis is made and possible future research contents are pointed out.