Delay line
The term delay line has multiple meanings:
- In telecommunication:
- A delay line is a transmission line, or equivalent device, used to delay a signal.
- A single-input-channel device, such as a single-input sequential logic element, in which the output channel state at a given instant, t, is the same as the input channel state at the instant t−n , where n is a number of time units, i.e., the input sequence undergoes a delay of n time units, such as n femtoseconds, nanoseconds, or microseconds. (Note: The delay line may have additional taps yielding output channels with values less than n.)
- In computing, delay line often refers to delay line memory.
- In digital signal processing, as in telecommunications, a delay line refers to a sequential logic element in which the output state at a given time n (in samples) is the same as the input was at the time n−L. Delay lines are generally expressed as z-L, where L is the length of the delay in samples. A unit delay (a delay of one sample) is therefore expressed as z-1.
An earlier version of this page came from Federal Standard 1037C and from MIL-STD-188.
