Time locked ... signals

[vjfaisal]

Hi every body


I need to know about time-locked signals .. Why they are called time-locked ? and if possible give examples ....in detail...


hope you all ...will share your knowledge....



regards

 

[albbg]

A time-locked signal is so called because it repeats itself over the time usually after a trigger event. Many physiological signals are time-locked: when a stimuls is given, after some time you will get the response, f.i in terms of a voltage pulse. Since the signal will repeat in the same way after each stimulus, sending a number of N stimuli and summing all the N responses it is possible to increase the S/N ratio. In fact the amplitude of the pulse after the sum of the response to N stimuli will be N times the single pulse amplitude; the noise, instead since it is uncorrelated by definition will increase as sqrt(N). Regards, Alberto