A message to be transmitted using AM is given by m(t): = 4 cos 400πt + 3 cos 300πt where the unit of time is milliseconds. It is to be sent using a carrier frequency of 30 kHz. a) What is the message bandwidth? b) Sketch its magnitude spectrum, clearly specifying the units used on the frequency axis. c) For a modulation index of 50%, write an explicit time domain expression for the AM signal. d) What is the power efficiency of the AM signal? e) Sketch the magnitude spectrum for the AM signal, again clearly specifying the units used on the frequency axis.

c) An audio signal 10sin 27(2000t) amplitude modulates a carrier 20sin 2π(200000t). i) ii) iii) d) How Sketch the amplitude modulated wave. Determine the modulation index? What is the frequency content of the modulated wave? AM broadenet stations. nodated in a 100 KH

03: The output voltage of a transmitter is given by the following envelope wave form. This voltage is fed to a load (RL= 12). What is the name of the modulator that can be used to generate DSB-AM, and draw the block diagram of this modulator? Then find: (a) The carrier frequency and the message frequency. (b) The double side band frequencies (USB and LSB). (c) The modulation index. (d) The carrier power and power in sidebands. (e) The total power. (f) Write the modulated wave equation at the output of the transmitter. Amplitude 20 volts 40 volts 20 Acti JA see. Go to

An AM carrier wave of frequency f = 1MHz with pack voltage of 20V used to modulated a signal of frequency 1kHz with pack voltage of 10v. Determine i. Modulation index (μ) ii. Frequencies of modulated wave? iii. Bandwidth

1- Indicate the sidebands in the modulated signal spectrum. 2- Calculate Signal-to-noise (SNR) at the input. 3- Select suitable channel model and explain the choice of your selection. NOTE:  The Carrier frequency used in the FM communication system is 43.67 MHz. The other parameters are given in image

Agiven FM signal is e(t) fm = Determine. to Cos [lont+ 8 Son (18²4t)] 1) The Carrier frequency 2) the modulation index 3) The Peak frequency deviction of

A. How many numbers of constellation points exist in phase for 3bit ASK?  B. What happens to the radio wave propagation when the frequency is below critical angle? C. If the mark frequency and space frequency are same then what happens to FSK? D. What is the Carson’s rule? E. What is the Maximum data rate in a minimum channel bandwidth is ? F. What is radio horizon and where is it used? G. What are the phase angle limitations of a BPSK? H. What is the change in channel capacity when two number of bits are increased?

779 @ ۱۰:۲۶ ص Asiacell l. assignment group.. Q/ consider the amplitude modulation wave shown in figure below with a triangular envelope. 1. What is the modulation index? 2. Determine the carrier and information frequencies. 3. Find the suitable value of time constant (RC) for envelope detector. Msec. 2 -2 -4 1comsec AM wave

In the case of FM modulation, when the value of the modulation index (β) is less than 0.5, we can say that the modulation spectrum tends to behave in the case of standard AM. True or false

3 An FM station, following FM broadcast standards, broadcasts at 105MHZ. Determine the modulation index and bandwidth of the transmitted FM signal, if the modulating signal frequency is (a) 150 Hz and (b) 1.5 kHz.