On The Single Carrier Frequency Domain Equalization And Realization For TD-SCDMA System

TD-SCDMA standard is one of three international3G standards, which is raised by China independently. Since the standard has been accepted by the International Telecommunication Union (ITU), it has got continuous improvement and development so far. With the rapid development of smart terminals, the demand for telecommunications service is no longer the simple voice communication, but the increasing demand for high rate data services. HSDPA (High Speed Downlink Packet Access) and HSUPA (High Speed Uplink Packet Access) were introduced to TD-SCDMA in R5and R6versions. After several years’development, although LTE is still not in large-scale construction; HSPA has become the highly competitive technology.This thesis first briefly describes the characteristics of wireless channel, as well as some techniques such as joint detection and channel estimation. Based on the algorithms, research was conducted on the single carrier equalization system and DS-CDMA with frequency domain equalization. Frame structure and the wireless channel are recommended by the standard802.16were applied in the simulation. Once the signal has been received, the local UW(Unique Word) and UW in the frame structure were utilized for channel estimation, and then the frequency domain equalization coefficient can be determined. By these two systems’before and after equalization signal analysis and the result of simulation, the linear frequency domain equalization is pretty effective to against the impact of the wireless channel signal.In the thesis, the TD-SCDMA HSDPA simulation platform is constructed based on TS25.222and TS25.223documents. The platform assumes signals are synchronized, combined with the characteristics of the TD-SCDMA system, the midamble code in the TD-SCDMA frame structure was used for channel estimation. The algorithm used in the frequency domain equalization is accordance with the algorithms for the previous two systems. By the simulation, improvement of system performance can be verified.Besides the materials mentioned above, this thesis did some research on the practical implementation of linear frequency domain equalization of the TD-SCDMA to meet the demands of engineering applications. After the simulation, DSP implementation was implemented according to the fixed-point algorithm, and the results of the DSP operation was examined, then comparison between MATLAB floating-point simulation results and the DSP operation results are performed. According to comparison, the practical implementation of linear frequency domain equalization of the TD-SCDMA meets the requirements of practical system regardless the complexity of the system realization and improvement of its performance.