TD-SCDMA Channel Coding And Decoding And Implementation Of Digital Intermediate Frequency On C-RAN

With the advent of the mobile Internet era, how to reduce the base station’s construction, maintenance and upgrade costs has become one of the core issues that must be addressed by mobile operators. China Mobile proposed a new wireless access network architecture C-RAN. C-RAN can effectively reduce the cost of network construction and maintenance, and provide users more flexible services.This dissertation referenced C-RAN architecture and 3GPP standard protocol, in terms of the baseband analyzes TD-SCDMA physical layer protocol, build the channel coding and decoding simulation and complete real-time implementation of channel coding and decoding on general purpose processor; in terms of digital IF, it studies the design and simulation of digital up/down converter applied to TD-SCDMA system and complete the implementation of digital up/down converter and real-time interface.Firstly, This dissertation analyzes TD-SCDMA physical layer protocol and C-RAN architecture, studies Viterbi decoding algorithm and Turbo decoding algorithm, designs and implements of the channel coding and decoding modules. In consideration of real-time system requirements and available hardware resources, This dissertation simplifies the decoding algorithm and completes multi-core parallel implementation.Secondly, This dissertation studies the algorithm design of digital up/down converter applied to TD-SCDMA system, simulates the IF design of the overall link, on the basis of simulation convert the simulation into the FPGA processing logic and completes the project implementation.According to the requirement of real-time interface between baseband and digital IF, this dissertation proposes a scheme.Finally, evaluates the system performance. Builds test cases in the laboratory environment and tests the data transmission function, the processing delay of modules, digital IF EVM and real-time interface performance. The results show that the channel coding and decoding modules meet the real-time requirement of TD-SCDMA system; in terms of digital IF, the loopback test shows digital up/down converter EVM is lower than 1%.This dissertation achieved real-time processing of TD-SCDMA channel coding and decoding on a general-purpose processor platform and complete the implementation of digital up/down converter and real-time interface, which verifies the feasibility of signal processing on general purpose processor and provides a reference for design of virtual baseband pool under C-RAN architecture.