The Design And Implementation Of Uu Interface Protocol In TD-SCDMA System On General Purpose Processor

With rapid rise in today’s mobile internet flow, it has become one of the core issues as how to reduce the base station’s construction, maintenance and upgrade costs and it must be addressed by mobile operators. Radio access network is a kind of assets upon which mobile operators survive; the research of wireless access technology is of great significance for both mobile operators and national broadband mobile communication plan.This paper studies the implementation of TD-SCDMA Uu interface protocol stack in general purpose processor platform on the back ground of new radio access network C-RAN architecture proposed by China Mobile Research Institute.The main work is refer to 3GPP standard protocols, analyzes the demand of TD-SCDMA Uu interface protocol stack on the way of access, data transmission, real-time signal processing; and then, according to demand analysis,deesign a scheme on network layer, data link layer protocol stack signal processing and data transmission as well as physical transmission signal processing; at last, inplement and verify the design scheme in Intel processor. The main contribution is composed of three sections as follows.Firstly, analyses the requirements of the software implementation of TD-SCDMA Uu interface protocol stack. Puts forward the Uu interface protocol stack function and performance requirements, and builds a software radio platform of Intel general purpose processor with a real-time operating system and virtual RRU, refered to C-RAN architecture with distributed RRUH and centralized baseband pool.Secondly, designs and implements Uu interface protocol stack. Based on hard real-time Linux system with Xenomai extensions, protocol stack software system structure design and module division are made, simultaneously, detailed design of major modules and module interfaces is given. According to design scheme, defines module interfaces in detail and implements the key modules, considering the real-time demand of protocol stack.Thirdly, makes engineering verification. Builds test cases in the laboratory environment and tests the main signaling processes, data transmission function, the processing delay of the key modules and bit error ratio respectively. The testing results show that the software protocol stack designed in this paper meets the requirements of TD-SCDMA radio access function, and in the AWGN channel, BER performance difference beteween measured and MATLAB fixed-point simulation is less than 2dB.In this paper, general purpose processor baseband processing capability in the C-RAN framework is verified by the TD-SCDMA software protocol stack. And the research rasults can be used for centralized virtual baseband pool design in the future, and with engineering practical value.