Ternary data transmission system
First Claim
1. A data transmission system comprising:
- a source of data signal in ternary form having a high level, a low level, and an intermediate level, the data signal having a bit time period equal to the minimum duration of each level;
the high and low levels representing a first binary value and the intermediate level representing a second binary value, the data signal following an encoding rule in which the data signal assumes different levels for successive occurrences of the first binary value separated by an odd number of bit time periods and assumes the same level for successive occurrences of the first binary value separated by zero or an even number of bit time periods;
means having a high pass characteristic for transmitting the data signal to a remote point;
means at the remote point for receiving the data signal;
means for deriving a ternary change representative signal equal to the received data signal minus a delayed version thereof; and
means for controlling the peak amplitude of the change representative signal to maintain a constant average value thereof.
4 Assignments
0 Petitions
Accused Products
Abstract
A source of a duobinary data signal is connected to a remote point by a coupling network having a high pass characteristic and transmission line. The data signal received at the remote point is subtracted from a delayed version thereof to derive the change representative signal, which is utilized at the remote point to regenerate and/or detect code violations of the data signal. Preferably, the received data signal is subtracted from a version thereof delayed by one bit time period. Circuitry generates an indication of a violation when, after assuming one extreme level in a given bit time period, the change representative signal again assumes the same level before assuming the other extreme level during a bit time period separated by an odd number of bit time periods from the given bit time period. Circuitry may also convert the change representative signal back to the duobinary data signal. Specifically, a three-state reversible binary counter is stepped up one state each time the change representative signal assumes its high level, is stepped down one state each time the change representative signal assumes its low level, and remains unchanged in state each time the change representative signal assumes its intermediate level.
45 Citations
16 Claims
-
1. A data transmission system comprising:
-
a source of data signal in ternary form having a high level, a low level, and an intermediate level, the data signal having a bit time period equal to the minimum duration of each level;
the high and low levels representing a first binary value and the intermediate level representing a second binary value, the data signal following an encoding rule in which the data signal assumes different levels for successive occurrences of the first binary value separated by an odd number of bit time periods and assumes the same level for successive occurrences of the first binary value separated by zero or an even number of bit time periods;means having a high pass characteristic for transmitting the data signal to a remote point; means at the remote point for receiving the data signal; means for deriving a ternary change representative signal equal to the received data signal minus a delayed version thereof; and means for controlling the peak amplitude of the change representative signal to maintain a constant average value thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. A data transmission system comprising:
-
a source of data signal in ternary form having a high level, a low level, and an intermediate level, the data signal having a bit time period equal to the minimum duration of each level;
the high and low levels representing a first binary value and the intermediate level representing a second binary value, the data signal following an encoding rule in which the data signal assumes different levels for successive occurrences of the first binary value separated by an odd number of bit time periods and assumes the same level for successive occurrences of the first binary value separated by zero or an even number of bit time periods;means having a high pass characteristic for transmitting the data signal to a remote point; means at the remote point for receiving the data signal; means for producing a ternary change representative signal equal to the difference of the received data signal subtracted from a delayed version thereof; means for controlling the peak amplitude of the change representative signal to maintain the change representative signal at a constant average value.
-
Specification