User Manual

8-VSB Modulator - DM8-R
The DM8-R 8-VSB modulator accepts an ATSC-compliant SMPTE 310M
digital bit stream. To modulate to the 8-VSB standard, the digital data
stream is first randomized and then forward error corrected (FEC)
through Reed-Solomon encoding, data field interleaving and trellis
coding. The FEC signal processing minimizes data errors in the digital
bit stream and reduces the chance of burst errors, while significantly
improving the system coding gain. The data is then equalized,
processed through pulse shaping filters and modulated to the 8-VSB
signal (centered at 44 MHz) utilizing Quadrature Vector Modulation
techniques. A crystal controlled oscillator provides excellent stability
and performance.
Front panel LEDs provide a quick indication of operating status and
performance of the modulator. In addition, a 9-pin serial port is provided
for the configuration of the digital linear and nonlinear pre-correctors.