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Electronics and Communication Analog Electronics Difficulty: Medium

The spread spectrum communication techniques are used in one of the following multiple access methods in satellite communication: Match List-I (Boolean logic function) with List-II (Inverse of function) and select the correct answer using the options given below the lists: List-I List-II a. $${\text{ab}} + {\text{bc}} + {\text{ca}} + {\text{abc}}$$ 1. $$\overline {\text{a}} \left( {\overline {\text{b}} + \overline {\text{c}} } \right)$$ b. $${\text{ab}} + \overline {\text{a}} \overline {\text{b}} $$ 2. $$\overline {\text{a}} \overline {\text{b}} + \overline {\text{b}} \overline {\text{c}} + \overline {\text{a}} \overline {\text{c}} $$ c. $${\text{a}} + {\text{bc}}$$ 3. $$\left( {{\text{a}} \oplus {\text{b}}} \right){\text{c}}$$ d. $$\left( {\overline {\text{a}} + \overline {\text{b}} + \overline {\text{c}} } \right)\left( {{\text{a}} + \overline {\text{b}} + \overline {\text{c}} } \right)\left( {\overline {\text{a}} + \overline {\text{b}} + {\text{c}}} \right)$$ 4. $${\text{abc}} + \overline {\text{a}} {\text{bc}} + {\text{ab}}\overline {\text{c}} $$ A source generates one of the five symbols s 1 , s 2 , s 3 , s 4 and s 5 once in every $$\frac{1}{{60}}$$ second. The symbols are assumed to be independent and occur with probabilities $$\frac{1}{4},\,\frac{1}{4},\,\frac{1}{4},\,\frac{1}{8}\& \frac{1}{8}.$$ The average information rate of the source in bits/second is: Indicate which of the following circuits could not demodulate SSB: The complex envelope of the bandpass signal $$x\left( t \right) = \sqrt 2 \left( {{{\sin \left( {{{\pi t} \over 5}} \right)} \over {{{\pi t} \over 5}}}} \right)\sin \left( {\pi t - {\pi \over 4}} \right),$$ centered about $$f = {1 \over 2}Hz,$$ is