Channel and Data Analysis System for Digital TV Broadcasting Using Modified Hilbert Transform

To analyze reception environments of ATSC Digital TV, CIR (Channel Impulse Response) analysis systems are widely applied. The receiving performances of conventional CIR analysis systems are not as good as those of commercial state-of-the-art receivers. There are difficulties in measuring and analyzing reception problems caused by multi-path interferences. To solve these problems, commercial DTV chip sets embedded CIR analysis system is proposed. Generally, commercial chip sets provide baseband (In-phase) channel data and field or segment sync data. For more precise analysis of measured I channel data, it is necessary to extract Q (quadrature) channel data components as well. This paper presents the technical requirements of CIR analysis system for DTV. In order to satisfy such requirements and measure more accurate magnitude and phase of CIR, a method to derive the quadrature data from the measured in-phase channel data is proposed. The proposed channel analysis system is implemented with a commercial DTV chip set and expedites the data analysis for use on DTV field test vehicles. Computer simulation and laboratory test results are provided to demonstrate the performance of the proposed channel analysis system.