公开(公告)号：US3906445A

公开(公告)日：1975-09-16

申请号：US51632574

申请日：1974-10-21

Applicant: MOTOROLA INC

Inventor： BECKMANN ROBERT M ,  LAMB JAMES A ,  NIEGLOS DONALD J ,  REYNOLDS GARY R

IPC: G06F13/00 ,  H04B7/26 ,  H04L1/00 ,  H04L29/12 ,  H04M11/00 ,  H04L1/10 ,  H04L1/06 ,  H04L1/08

CPC classification number: H04L1/00

Abstract: An alphanumeric terminal providing a digital message having a fixed portion consisting of the address of the receiver in sixteen bits, followed by a repeat of the address in sixteen bits, a status indication in four bits, a request in four bits and an acknowledge plus an indication of whether text follows in two bits; and a variable portion consisting of a text message of zero to 384 bits, which fixed and variable portions of the message have parity bits inserted after each digital word and are delayed and interleaved (every other bit) with a similar undelayed message to form a composite message, which composite message is preceded by a pseudo random code of 127 bits. The terminal also includes noise and error detection circuitry, associated with the receiver, which separates the two interleaved messages and compares them for similarity, checks the parity bits for correctness and compares the amplitude of each bit to a predetermined upper and lower level to determine whether the bit is noise or a portion of the signal. From the various noise and error checks the terminal then provides a decision as to whether a digital word is good or bad and, if the digital word is in error and comes within the text portion of the message, an asterisk appears in the visual display so that the operator can mentally determine what the character should be.

Abstract translation: 一个字母数字终端提供数字消息，该数字消息具有由十六位中的接收者的地址组成的固定部分，随后以16比特重复地址，4比特的状态指示，4比特的请求和确认加上 文本是否以两位表示; 以及由零到384位的文本消息组成的可变部分，该消息的固定和可变部分在每个数字字之后插入奇偶校验位，并且以类似的未延迟消息被延迟和交织（每隔一个位）形成复合 消息，哪个复合消息之前是127位的伪随机码。 终端还包括与接收机相关联的噪声和错误检测电路，其分离两个交错消息并将它们进行比较，以便进行相似性，检查奇偶校验位的正确性，并将每个位的幅度与预定的上限和下限进行比较，以确定是否 该位是噪声或信号的一部分。 从各种噪声和错误检查，终端然后提供关于数字字是好是坏的决定，如果数字字错误并且在消息的文本部分内，则在视觉显示中出现星号， 操作者可以精神上确定角色应该是什么。