Design Of Signal Modulation Quality Testing System For DTMB System

DTMB is the mostly used digital television terrestrial broadcasting standard in China,and the quality of the signal modulation is directly related to the performance of DTMB transmission system.Designing a testing system,which can automatically identify the system information of the DTMB signal,and can accurately measure the modulation quality parameters,has a positive significance on the manufacturing,debugging of the digital TV equipment,the promotion and application of the Digital TV industry.The main work of this paper is summarized as follows.1.Analysis and research on the main work to develop the testing system.This paper introduces the processing of the sender based on DTMB standard.Then analyzes the main processing and principle of the DTMB receiver,the characteristics of the DTMB channel,finds that the main work to the design DTMB signal modulation quality testing system is the algorithm design of the DTMB signal synchronization and channel estimation and equalization.2.Research on demodulation synchronization algorithm for DTMB system.This paper analyzes the characteristics of the signal frame structure of DTMB,and designs the identification algorithm of the frame head mode,the symbol synchronization algorithm of DTMB signals,the algorithm of frequency offset estimation and compensation.Finally,verifies the algorithm's effectiveness by simulations.3.Research on channel estimation and equalization in DTMB system.According to the different frame head mode of the DTMB signal,this paper designs different channel estimation and equalization methods,reduces the influence of inter symbol interference in channel estimation,improves channel estimation accuracy,and validates the method by simulation.4.Design of DTMB signal modulation quality testing software.Designs the general framework of software and the function modes,and developes a DTMB signal modulation quality testing software based on synchronization and channel estimation algorithm Finally,specific hardware platform is combined to test the accuracy of the system.