Research On Compact RF Front-End For Massive Mimo System

With the coming of 4th generation,5th generation has become a research hotspot in the field of mobile communication at home and abroad. As a key technology of 5th generation, massive MIMO technology can not only multiply spectrum efficiency and power efficiency, but also significantly reduce the interference, and its simple and compact transceiver structure can get close to optimal performance.This thesis comes from a research project "Massive MIMO System of Alcatel-Lucent Shanghai Bell", mainly focuses on the design of a 3.5GHz compact receiver for massive MIMO system which will be applied in future 5th generation wireless communication.Combined with specification analysis with several popular RF systems, digital intermediate frequency structure is adopted, TDD duplex system, radio frequency is 3.5GHz and intermediate frequency is 215.04MHz, bandwidth of whole system is 20MHz. Based upon the solution, specification evaluation and link budget simulation is implemented to identify performance allocation and specific realization for individual parts. In addition, the thesis optimizes the design of essential modules and gives solution to system measurement. Upon this, a complete transceiver module is designed and tested.The thesis, finally, presents measurement of noise figure, gain flatness, image rejection ratio, EVM, sensitivity, dynamic range and transceiver switch speed. For this receiver, noise figure is less than 4.5dB, gain flatness is less than 0.45dB, image rejection ratio is more than 38dB, EVM of 20MHz QPSK,16QAM and 64QAM is respectively less than 2.9%,2.3% and 1.9%, EVM of 20MHz TDD-LTE is less than 1.2%, sensitivity is-86dBm, dynamic range is more than 61dB, transceiver switch speed is less than 1.9μs. The measurement presents the RF receiver with excellent performance.