Research On Transmission Key Techonology And Prototype Verification Of Massive MIMO System

With the rise of the Internet of things and the rich of mobile Internet service types, the data transfer rate and service quality of cellular mobile communication are put forward higher requirements. Due to the privilege of fully exploiting the degrees of freedom in spatial dimension, and therefore obtaining better spectrum efficiency power efficiency, massive MIMO has attracted wide attention at home and abroad, and become one of the most promising wireless transmission technologies in the next generation of wireless communication system. However, massive MIMO system, which install large scale antenna array at base station, not only improve the system performance but also bring unprecedented challenges, such as the design of transmission schemes, the dramatic increase in system hardware complexity and computational complexity and so on. It is a very challenging issue to how to realize massive MIMO prototype system. This thesis will study massive MIMO system, and focus on the transmission scheme and the hardware design of a massive MIMO system.Firstly, we investigate the physical layer technology of massive MIMO, including system model, transmission scheme, uplink and downlink data transfer process, the existing prototyping platforms and so on. Starting from the system model of TDD massive MIMO system for multi-cell multi-user, we analyze the performance gain and the necessity of building massive MIMO prototyping system. Then we focus on illustrating the existing massive MIMO prototyping systems (e.g. Argos and LuMaMi), and transmission schemes (e.g. joint spatial division and multiplexing, JSDM and massive beam-spatial division multiple access, MB-SDMA).Next, this thesis studies both the design of physical layer and system architecture for a massive MIMO prototyping system. As for the physical layer, we begin with the wireless frame format design naturally, and then determine uplink and downlink data transmission processes for our system link-level simulation so that providing theoretical basis for the hardware implementation of subsequent chapters. In the system architecture design, the feasibility analysis of hardware architecture and implementation requirements is performed, and the system test schemes are still provided to assure the feasibility of system architecture.Finally, we pay attention to the function module design and hardware implementation of our massive MIMO prototyping system, such as the OFDM modulation and demodulation module, the base station side data routing and aggregation module, channel estimation and equalization module and etc. After giving system parameters and physical picture of both base station side and mobile station, the measurement results of our established massive MIMO prototyping system are also supplied in this thesis. The results indicate that the massive MIMO prototyping system constructed in this thesis successfully realize the system requirements and can simultaneously support at most twelve users’ real-time uplink video stream transmission.