Research On The Data Link Technologies Of 5G Remote RF Unit

The fifth generation mobile communication technology is focused on integrating various mobile communication technologies to form a complete information network.Distributed base station,as the development and evolution of traditional base station model,its core idea is to make the traditional acer base station dived into baseband processing unit(BBU)and rf remot unit(RRU).The BBU and RRU are connected by optical fiber,and the network is flexible.RRU can be used to set up a community,which has important research significance and application value in indoor coverage and road coverage.The main goal of this paper is to design and implement the digital link of the 5G rf remote unit and the transmission from BBU to the antenna.First,it studies the CPRI protocol,and carried out detailed study on frame structure,physical layer,subchannel and start-up process,and determined the feasibility of BBU to RRU data transmission.Then it introduces the development envirroment and hardware platform of RRU digital link,which provides the foundation for later design and implementation.Then,some key technologies in digital link are studied,and the functional modules are designed and divided into various modules,including CPRI interface module,cpri_map module,control module and JESD204B interface module.Finally,the test platform is built to verify the function and performance of digital link.The test results show that the digital link supports the communication between BBU and RRU,and accomplished CPRI interface whose line rate is 9.8304Gbps;the communication between BBU and RRU has achieved PP1S sync;Upstream and Downstream links' rf transceiver switch is real time and programmable;Data can be high-speed transmitted from RRU to the antenna,and digital link's performance achieves the desired design goals.