Research And Implementation Of Physical Layer Uplink For TD-SCDMA

TD-SCDMA was proposed by China as one of the international CDMA standard s for3G mobile communication. It has some advantages over WCDMA and CDMA2000:asymmetric frequency band for its TDD technology; flexible frame structure suit able for asymmetric service; higher expected theoretical spectral efficiency; smart ant enna, etc. The paper presents the work that the author has participated in "Design of TD-SCDMA Baseband in SL3000Platform ". In this project, the author was involved in the requirement design of the uplink, the implementation of some modules in DSP, time and space optimization, and debugging tasks. Based on the characteristics of the platform as well as the features of DSP, the whole process of the uplink was designed and optimized, in order to meet the requirements for both the memory and the running time of the DSP kernel.The paper firstly introduces the background and advantages of TD-SCDMA over other3G standards. First the paper presents the frame structure of the TD-SCDMA system, as well as the network architecture and the air interface in the physical layer. Then the transport channel and the physical channel are analyzed, especially the functionalities of the baseband module in the physical layer. Analysis and comparison the advantages and disadvantages of single-core DSP platforms and multi-core DSP platforms, illustrates the advantage of the hardware platform used in the project.Next, the paper describes the hardware environment of the physical layer and two DSP cores of uplink:bsp3core and BBE core. In our design, thinking of the memory size limit in bsp3core, we choose the rate of matching module, physical channel mapping module and so on from the bsp3core transport to the BBE core.Then we addresse the implementation of some of the modules and the optimization of the core modules through time and space optimization, intensive analysis of the encoder and rate-matching optimization. The optimization commands of the hardware platform are also used to optimize the rest of the modules. As for the optimization of storage space, we use application of spatial multiplexing ideas which the last module variable can be used in the next moduleFinally, we summarize the paper and addresses direction of the future work.