Products by Application

Video Measurements

Progress in the CATV world today means many things, Digital cable, High Definition video, (DOCSIS) data services (including high speed internet service), and programming on demand. Delivery of these services requires new equipment with improved traffic handling capability to accommodate the increased data rates. In general, digitally modulated, QAM signals will require new Cable Modems, Head-end Cable Modem Termination Systems, and improved Fiber Optic link equipment to transmit these signals over long distances with a minimum of distortion. Verifying the performance of this equipment requires new methods and Noise Based Test Equipment will play an increasing role. For test purposes, the nature of digitally modulated signals is closely emulated by AWGN (Additive White Gaussian Noise). BER-Bit error rate vs. Signal to Noise ratio (Es/No, C/N) is a key performance parameter for any digital communication system. This parameter determines how fast information can be transmitted and received for a given channel condition. The PHY-07 DOCSIS modem interoperability test calls out specific BER vs. C/N performance levels for both 64 QAM and 256 QAM signals. AWGN must be generated and combined with the signal in the correct ratio to properly evaluate BER vs. C/N. The general purpose, UFX7000A series is used for broadband video applications, and the UFX99CA has additional outputs for connection to other test equipment. The UFX 7109, and the UFX 7102, formerly the NC7102 are specified in the CableLabs document in the following link: http://www.cablelabs.com/udcp/downloads/TP-ATP-M-UDCP-I02-070105.pdf