Let m1(t) and m2(t) be two message signals and let x1(t) and x2(t) be the corresponding modulated version. Which among the following statements is/are correct?
1
When the combined message signal m1(t) and m2(t) DSB modulates a carrier Ac cos 2πfct, the result is the sum of the DSB amplitude modulated signals x1(t) and x2(t)
2
When the combined message signal m1(t) and m2(t) DSB modulates a carrier Ac cos 2πfct, the result cannot be the sum of the DSB amplitude modulated signals x1(t) and x2(t)
3
When the combined message signal m1(t) and m2(t) frequency modulates a carrier, the modulated signal is equal to the sum of x1(t) and x2(t).
4
When the combined message signal m1(t) and m2(t) frequency modulates a carrier, the modulated signal cannot be equal to the sum of x1(t) and x2(t).