سؤال حول FM modulation(عاجل ارجوكم)

[CENTER]بسم الله الرحمن الرحيم

عندى بعض الاسئله حول ال FM MODULATION
ارجوا ان تساعدونى فى ايجاد الاجابه

احتاج الى تعريف لل noise

3 types of noise and frequancy range of each of them
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What’s meant by Pre-emphasis and De-emphasis blocks? How they are

connected in the communications systems? and what are their importance?