A Research Of Coordinated Multi-Point Transmission Technology In LTE-A Heterogeneous Network

With the rapid development of mobile Internet, Indoor, wireless hotspots and low-speed will become more important application scenarios in the age of mobile Internet. The network based on Macro e NB has been difficult to meet demands. Therefore, Het Net emerges as the times require.Het Net can significantly improve the system throughput and spectrum efficiency, but it will introduce more complex interference at the same time. Het Net is the current challenge and future direction. An important feature of LTE-Advanced is to support the Het Nets, and the future of 5G networks will also be ultra-dense Het Nets.The core issues of this paper are to optimize the system performance and improve spectral efficiency and energy efficiency through resource allocation. Around the core issues, this paper did research on 4 points:(1) In order to improve the performance of cell edge users, this paper applied Co MP into Het Nets. Results of simulation on the ICI and the status of cooperation in Het Nets show that increasing the number of Pico e NB or expanding the range of Picocell, will reduce the load of Macro e NB, but also enhance the interference of overall system.(2) In order to improve the spectral efficiency of JT-Co MP, this paper studied on joint transmission scheme Co MP-MU-MIMO, and regarded Co MP-MU-MIMO as MIMO. Eliminate inter-user interference by precoding, and compare the performance of different user pairing algorithms.(3) In order to optimize the performance of the system, this paper studied on the resource allocation of collaborative users under PBPC(Per Base Station Power Constraints). This paper considered three kinds of power allocation policy: maximum the system sum capacity, equal power allocation and maximum user rate allocation.(4) Finally, this paper studied on resource allocation and performance optimization of non-Co MP users. Most users in the system only need a service base station, which largely determines the overall performance of the system.Ultra-dense Het Net is the trend of mobile communication, and the interference problem in Het Nets will increasingly prominent. It’s significant to apply Co MP into Het Nets to improve the performance of edge users through dynamic resource allocation.