preamble

noun

1. a preliminary introduction to a statute or constitution (usually explaining its purpose)

preamble

verb

1. make a preliminary introduction, usually to a formal document

1. 序文；导言；开场白
A preamble is an introduction that comes before something you say or write.

e.g. The controversy has arisen over the text of the preamble to the unification treaty...
针对统一条约的序文出现了争论。
e.g. 'I would like you to return to the villa as soon as possible,' she said without preamble.
她开门见山地说：“我想让你尽快回到别墅。”

1.

1. 导言：每一个LaTeX文稿都包含导言(preamble)和正文(body)两个部分. 导言是一组命令的集合,它指定整个文稿的全局参数,如页面格式、文本尺 寸、页码、页眉和页脚等. 导言部分必须包含documetclass命令,以指定文档的版式类型,

2. 前同步信号：仿真结果表明:两方案在误比特率(BER)方面性能改善显著,同时还有效降低了前同步信号(preamble)和信道探测信号的长度,对于提高传输速率具有重要意义. 另外,信道编码方式也需要深入研究. 采用信道编码直接降低了有效通信速率,