Research And Testing For C-RAN System

Today the task of building a radio access network architecture is coming upon us with rapid development of internet and technology. C-RAN is a clean system,which consist of Cooperative radio, Centralized signal processing, and real-time Cloud infrastructure. Through technology of coordination and virtualization, it can reduce the number of server rooms and the consumption of energy, realize resources sharing and dynamic scheduling, also improve spectrum efficiency. In addition, it can also acheive goals of high bandwidth, low cost and flexible running. C-RAN aims at solving the problems brought by the rapid development of internet technology, creating profit and sustainable business in the future.This paper introduces a deep research into the technology in testing the system. First, it talks about the system and other key technologies like dynamic baseband pool and virtualization.Then it analyzes possibility of C-RAN which is based on GPP server.The BBU pool uses General Purpose Processors to build up C-RAN system test platform and carry out management of users and environment through RHEV-M3.1.The relationship between BLER and SNR under different CQI is simulated.In order to check if the channel meets the requirement, with the application of 89600 VSA channel modulation of the idle signal of TD-LTE has been tested.The test includes downlink primary synchronization signal, auxiliary synchronization signal, special reference signal area, downlink broadcast channel, shared channel and indication channel.This paper also analyzed the idle signal of the C-RAN architecture, including the time domain waveform and spectrum characteristics of the idle signal, as well as collect statistics of EVM of downlink channel.it tests performance of the network capacity, latency between the BBU and RRU, and latency and ability of the bandwidth within the BBU, as well as latency and ability of the bandwidth between BBUs.The feasibility of network expansion is tested. In the final,after building up the testing platform, with the Altair UE to test the TD-LTE network in many ways, including ultimate testing, FTP the upstream and downstream flow, and fluency of the streaming media.this paper records statistics about the live migration of baseband resources, redundancy backup, baseband resources triggered by load and the change of power consumption. The result is that the platform is completely qualified.