comprehensive viva voce ppt
TRANSCRIPT
Comprehensive Viva-Voce
Under the Guidance of Mr.R Kiran Rao, M.Tech Asst.Professor
Presented BySrishti.P
08E31C0489IVth Year, ECE-B
Contents
Analog Communication
Sampling Theorem
Pulse Amplitude Modulation
Pulse Position Modulation
Pulse Width Modulation
Pulse And Digital Circuits High Pass Filter
Low Pass Filter
Attenuator
Clampers
Contents
Electronic Devices And Circuits
Forces ,Fields ,Electric Potential, Intensity.
PN Junction
Different types of Diodes
Rectifiers
Cellular And Mobile Communication
Frequency Management
Set-up Channels
Channel Assignment
Handoff
Analog Communication
Sampling Theorem
“A continuous-time signal may be completely represented in finite samples and recovered back if the sampling frequency is fs> 2fm”
Pulse Amplitude Modulation
Demodulation of PAM
Pulse Position Modulation
Demodulation Of PPM
Pulse Width Modulation
Modulation OF PWM
Demodulation Of PWM
Comparison of PAM ,PPM,PWM
Pulse And Digital Circuits
HIGH PASS RC CIRCUIT
The circuit which attenuates low frequency signals and transmits only high frequency signals is called a high pass circuit.
Sinusoidal Input
Step Input
Ramp Input
Pulse Input
Square-Wave Input
LOW PASS RC CIRCUIT
A low pass RC circuit is a circuit, which transmits only low frequency signals and attenuates or stops high frequency signals.
Sinusoidal Input
Step Voltage Input
Pulse Input
Square Wave Input
ATTANUATORS
A circuit which reduces the amplitude of the input signal is called as the attenuator.
NON-LINEAR WAVE SHAPING
“The process where by the form of a sinusoidal or non-sinusoidal signal is altered by transmitting through a non-linear network is called as non-linear wave shaping”.
CLAMPER CIRCUITS
Clamping is a process of introducing a dc level into a signal.
NEGATIVE DIODE CLAMPER
POSITIVE CLAMPER
Voltage Doubler
Charged Particles
Electronic Devices and Circuits
Field Intensity E
The electric field intensity can be defined as the force per charge on the test charge.
Electric Potential Due to Point Charge
Electric Potential at a point P= work done in bringing a point charge from infinity to point P
Force and Motion in Magnetic Field
The PN junction
Formation of Depletion Layer
Forward Biasing of PN Junction Diode
Reverse Biasing of PN Junction Diode
HALF-WAVE RECTIFIER
FULL WAVE RECTIFIER ( FWR )
Cellular and Mobile CommunicationsFrequency Management
The function of frequency management is to divide the total number of available channels into subsets which can be assigned to each cell either in a fixed fashion or dynamically.
Numbering the channels and Grouping into subsets
• The total number of channels is 666 channels. A channel consists of two frequency channel bandwidths, one in the low band and one in the high band.
• The 666 channels are divided into two groups: block A system and block B system.
• Each block has 333 channels. The 42 set-up channels are assigned as follows: Channels 313-333 block A Channels 334-354 block B
• The number of voice channels for each system 312. Since there are 21 set-up channels for each system
Channel Assignment
In a fixed channel assignment there are two types of channels assigned: set up Channels and Voice Channels.
Set-up channels
There are 21 set-up channels assigned each cell in a K = 4, K=7,or K = 12 frequency-reuse pattern.
Voice channels
One way of dividing the total voice channels into 21 sets. The assignment of certain sets of voice channels in each cell site is based on causing minimum co-channel and adjacent-channel interference.
Fixed Channel Assignment
Adjacent-channel assignment
Channel sharing and borrowing
HANDOFF
Handoff Initiation
Intersystem handoff
Cell site handoff scheme
Dropped calls
The definition of a dropped call is after the call is established but before it is properly terminated. The definition of “the call is established” means that the call is setup completely by the setup channel
The perception of dropped call rate by the subscribers can be higher due to:
1. The subscriber unit not functioning properly (needs repair).
2. The user operating the portable unit in a vehicle (misused).
3. The user not knowing how to get the best reception from a portable unit
(needs education).