What is meant by pre-emphasis and de-emphasis?
Answer Posted / debopam banerjee
PRE-EMPHASIS :-
In an FM system the higher frequencies contribute more to
the noise than the lower frequencies. Because of this all FM
systems adopt a system of preemphasis where the higher
frequencies are increased in amplitude before being used to
modulate the carrier. The transfer function sketched above
is used for a preemphasis circuit for FM signals in the FM
band. The Time T = 75µs. For FM systems in the FM band m ~ 5
resulting in a S/N improvement of 19dB. With preemphasis
this can be increased by 4dB for a total of 23dB.
DE-EMPHASIS :-
At the receiver the higher frequencies must be deemphasised
in order to get back the origunal baseband signal. The
transfer function of the deemphasis circuit is shown above.
| Is This Answer Correct ? | 94 Yes | 25 No |
Post New Answer View All Answers
For what a triggering circuit is provided in a cro?
Define mean life of a carrier.
what is reconfiguration of E1
working and uses of current transformer?
Why temperature coefficient of resistance of a semiconductor is negative?
Explain to find resistivity?
Pls send Syllabus of Jr.Eng grade2 electronics e.n.no 02/2008 & model qustions to my id amarlalmeppurath@yahoo.com
What is rfid in developing stage?
I had completed my diploma in electronics and communication. Currently am working with a pvt. ltd. (with two years of experiences) company which makes panel using plc, VFD(drivers) and scada monitoring system. so should i get supervisor licence for my supervisor post???
Explain how to identify how many states the ripple counter is having by looking at the figure as it can also have some invalid states?
Why should you chosen this job
at the time of doing second year which course can we study..? and where we should study...?
What is the gauss`s law?
what happen when the rectifier circuit is connect with the tube light?
What are the differences between voltage and current controlled devices?