公开(公告)号：US5001728A

公开(公告)日：1991-03-19

申请号：US235111

申请日：1988-08-23

申请人： Friedrich Fu/ ldner

发明人： Friedrich Fu/ ldner

IPC分类号： H03M5/12 ,  H04H20/34 ,  H04H40/18

CPC分类号： H04H20/34 ,  H03M5/12 ,  H04H40/18 ,  H04H2201/13

摘要： A binary encoded phase modulated signal (biphase signal) is demodulated by determining the period of time (T) elapsing between each two successive jumps in the level of the biphase signal; providing a clock frequency (B) approximately corresponding to the bit rate of the biphase signal with the aid of a clock generator; comparing the clock duration (1/B) of the clock frequency with the period of time (T) between each two jumps in level; and, with the aid of a sample and hold circuit controlled by the clock frequency (B), always ascertaining the logical value of the biphase signal and emitting a signal corresponding to the logical value whenever, immediately prior to a bit period, twice in succession, a value between 1/4 and 3/4 of 1/B is ascertained for the period of time (T), or a value between 3/4 and 5/4 of 1/B is ascertained for the period of time (T). Additionally, a signal characterizing interference can be emitted, or the output can be suppressed, if a value less than 1/4 of 1/B or greater than 5/4 of 1/B is ascertained as the period of time (T). This makes it possible, in the presence of a biphase signal, to recover the original data with high security in a relatively simple manner.

摘要翻译： 二值编码相位调制信号（双相信号）通过确定双相信号电平中每两个连续跳变之间经过的时间（T）来解调; 借助于时钟发生器提供近似对应于双相信号比特率的时钟频率（B）; 将时钟频率的时钟持续时间（1 / B）与每两个跳跃之间的时间段（T）进行比较; 并且借助于由时钟频率（B）控制的采样和保持电路，总是确定双相信号的逻辑值并发出与逻辑值相对应的信号，每当紧接在位周期之前，连续两次 ，确定1 / B的1/4和3/4之间的值（T），或者确定1 / B的3/4和5/4之间的值（T ）。 另外，如果确定小于1 / B的1/4或1 / B的5/4以上的值作为时间段（T），则可以发出表征干扰的信号，或者可以抑制输出。 这使得在存在双相信号的情况下可以以相对简单的方式以高安全性恢复原始数据成为可能。