DVBC调制QAM模式ANNEX B分析.pdf

Versatile Digital QAM Modulator WP-STXIIQAM-2.0 White Paper Combined with enhanced DSP blocks, the logic structure of Altera’s Stratix® series and Arria® series FPGAs offer a flexible way to implement the key elements of the Quadrature Amplitude Modulation (QAM) signal-processing path in any region. With their innovative logic structure, enhanced dedicated DSP blocks, and the revolutionary memory blocks, Stratix series and Arria series FPGAs are perfect for cable head-end system designers who want flexibility and speedy time to market. In addition to these advanced features, Altera also provides an extensive set of IP cores and EDA tools to help simplify the design process. Introduction With the advancement of digital entertainment and broadband technology, there are various ways to send digital information to end users such as cable and satellite subscribers. The current digital cable systems deployed around the world use the QAM standard, which defines the input data framing structure, channel forward error encoding, filtering, and QAM mapping. With digital television (DTV), the typical downstream signal uses either a 64- or 256-QAM scheme. The data source is either ATM packets or MPEG2 transport packets (used for DTV applications). The differences in the QAM standards are in the error coding section, which is broken down by Annex A, B, or C. The North American standard uses Annex B