STM—4帧定位方案的最佳设计

The Optimum Design of STM-4 Frame Alignment

本文根据CCITT建议提出了STM—4帧定位方案的常规设计方法,分析了采用容错技术后改进了的帧定位方案。同时,采用1比特容错还是2比特容错;在帧同步态和失步态可否采用不同长度的帧定位码;以及帧定位码的码型等,也作了具体分析。最后提出了一种STM—4帧定位的优选方案,在不过于增加物理实现难度的前提下,其各项指标均优于CCITT建议。

This paper presents an usual design for STM鈥? frame Alignment as per CCITT proposals. An improved design scheme for the STM鈥? frame alignment by using error tolerance technique is analysed. Some practical technologies, such as using of one bit or two bits as error tolerance, possibility of using different lengths of frame alignment codes in the in-frame and out-of-frame status, and the optimum code pattern for frame alignment are also analysed. Finally, an optimum design scheme for the STM—4 frame alignment without much more additional physical difficulties, is proposed, the performance is much better than the specifications of CCITT recommendations.