5.7 Design an STS switch for 128 primary TDM signals of the CCITT hierarchy (30 voice channels per input). Blocking should be less than 0.002 and the loading is 0.2 erlang per channel. How many time slot interchange modules are needed? What is the complexity of the switch? Repeat Problem 5.7 for a TST design.

Q4. Consider the QPSK digital modulation scheme (a) What does the abbreviation QPSK stand for? (b) Sketch an I-Q constellation diagram for this modulation scheme. (c) State the number of bits per symbol. (d) If the bit rate that is achieved with this modulation scheme is 128 Mbit s-, what is the baud (symbol) rate?

3. a) What does TDMA stand for? What does it mean? Explain or sketch the concept. b) What is PAM? What does it stand for? Explain or sketch how the modulated signal looks like.

4) Describe cell phone standards and systems such as FDMA(AMPS/TACS), TDMA (GSM/IS-54) and CDMA (IS-95).

Please show a two-terminal general modulation channel model. And for the random parameter channel, what is the main effect on signal transmission?

2. (a), What is the bäsic. limitation of SSB scheme?. How climinated by VSB modulation? is it modulation b) Draw the block diagram of super heterodyne AM réceiver and explain the function of IF amplifier.

c) Draw a block diagram of a typical digital communications system including both transmit and receive paths and describe the nature of the signals generated by each of the blocks. Briefly describe what happens within the Modulator element and explain what is meant by the term 'up-conversion'.

a) What is the advantage of increasing the switching frequency in switching converters (Buck, Boost etc.)and causes disadvantages to arise? b) General characteristics of IGBT and MOSFET, such as the current, voltage and switching frequency they can be producedCompare in terms of values. c) Output current and voltage ripples for a Buck-Boost type power converterWhat variables do (ripples) depend on? Explain.

It's urgent please solve asap.

7+6) This QUESTION FROM DIGITAL COMMUNICATIONS II course.