论文部分内容阅读
一、重新考虑性能测量问题 我们不知道什么可能危害我们,如果我们不考虑数字电视(DTV)和NTSC之间的差异,这将对我们有危害。例如,长时间以来群时延是“需要”的而并非是特别有意义的性能测量之一,因为它基本上只影响信号的彩色分量。NTSC群时延被定在FCC规定的曲线的±0.05ms～±0.1ms范围内。但是,DTV群时延在整个6MHz信道应当是±0.015ms,这是比迄今很少得到注意的规范严格得多的限制性要求。
First, reconsider the issue of performance measurement We do not know what could jeopardize us, which would be harmful to us if we did not consider the differences between digital television (DTV) and NTSC. For example, group delay has been “required” for a long time and is not one of the particularly meaningful performance measures because it basically affects only the color components of the signal. The NTSC group delay is set within ± 0.05ms ~ ± 0.1ms of the curve specified by the FCC. However, the DTV group delay should be ± 0.015 ms across the 6 MHz channel, which is a much more restrictive requirement than the one hitherto little noticed.