数字电视的测试分析

有线数字电视的测试主要包括两个方面:码流分析测试和QAM分析测试。其中,射频和调制质量关键指标包括MER(调制误差率)、BER(比特误码率)、C/N(载噪比)、Power Level(平均功率)、EVM、星座图等。针对国内目前多数HFC网络中模拟信号和数字信号同时并存传输的技术体制,测试也需要考虑数字和模拟两方面因素。关于双向网络的测试,数字信号发射设备的测试和网络信号传输设备的测试都做了相关介绍。最后介绍了信道功率的测量和数字信号电平的测试。

Digital TV Testing Analysis

This paper firstly discusses the differences between the digital cable television and the analog cable television.Digital cable television testing includes two major aspects:stream testing analysis and QAM testing analysis.The radio frequency modulation and the quality of key indicators include the MER(modulation error rate),BER(bit error rate),C/N(CNR),Power Level(average power),EVM,constellation,and so on.For the majority of the current domestic HFC networks,analog and digital signals' are transmitted at the same time and it needs to consider both the analog and digital factors in the equipment testing.This paper introduces the testing of two-way network,digital signal transmitting equipment and network signal transmitting equipment.Finally it focuses on the measurement of channel power and the test of digital signal level.