YILDIRIM BEYAZIT UNIVERSITY EE 305 – TELECOMMUNICATIONS 1 PRELIMINARY MANUAL – 3 – Frequency Modulation Preliminary work:
1) A wiring diagram of TETRA-BB hardware blocks to generate a FM Modulated signal is given in Figure 1.
Figure 1: FM Modulator block diagram & TETRA-BB connections a-) Draw the time domain expression of the output signal of master signals module tuned to 2 kHz for message signal. It provides an sinusoidal output signal with a peak to peak amplitude of 4V (for a time range of 0- 2 ms). b-) Draw the time domain expression of the output signal of an adder module and set to gain parameter (g) of adder to 2. (for a time range of 0 – 2 ms).
c-) Set peak to peak amplitude of the sinßs signal in Function generator to 4V and frequency of signal 50 kHz. Calculate and Draw the time domain expression of output signal of a Function Generator module (for a time range of 0 – 2 ms). d-) In order to compute the frequency spectrum of the generated FM signal, use to Bessel functions and determine serial expression of the modulated signal. e-) Sketch the spectrum of the FM modulated signal. f-) Compute the bandwidth by using Carson Bandwidth Rule and compare with frequency spectrum.