This was a project presentation for the Digital Signal Processing course

1. Recursive Discrete Time Oscillator
with Dynamic Amplitude Control
G.K. Vikram (10115044)
Arka Ghosh (10115024)
Debasmit Das (10115039)

2. TWO ENTITIES
• Recursive Oscillator – It is a numerical
oscillator which can be described by a
recurrence relation.
• Dynamic amplitude control - The control
technique used is Automatic Gain Control. It is
used to encounter accidental instability.

3. Recursive Oscillator
BLOCK DIAGRAM

4. STATE EQUATION
|zI – A | = 0 and |z|=1
Yields the condition of a sustained oscillations -
ad – bc =1 and | a+d | < 2
So these parameters determine whether the oscillator is stable .

5. a=0.5 ,b=-3,c=0.25,d=0.5

7. a=0.5 , b=3, c=0.5 , d=0.6??

8. Calls for Automatic Gain Control
• Gain is tuned according to the amplitude of
the signal
• If signal is weak then gain should be large and
if signal is strong gain should be weak.
• Applications : Radio Sets , Amplifiers
• No Approximation of Gain required

11. REFERENCES
• Clay S. Turner , A Discrete Time Oscillator for a
DSP based Radio
• Clay S. Turner, DSP Tips & Tricks, IEEE Signal
Processing Magazine
• www.google.co.in

12. THANK YOU
SPECIAL THANKS TO DR. P. SUMATHI