Pulse Modulation
DIGITAL TRANSMISSION
Definition:
Transmittal of digital signals between two or more points in a communications system.
Advantages of Digital Transmission
• Noise immunity
• Ease of processing and combining
• Ease of measuring and evaluating
•
Disadvantages of Digital Transmission
• Requires more bandwidth
• Necessitates encoding and decoding circuitry
• Requires precise time synchronization
• Incompatible with older analog transmission systems
Pulse Modulation
Pulse Modulation consists essentially of sampling analog information signals and then converting those samples into discrete pulses and transporting the pulses from a source to a destination over a physical transmission medium.
Pulse Modulation is a method of modulation that represents information as a train of pulses, wherein one or more characteristics of each pulse change with the input signal's variation.
Methods of Pulse Modulation
• Pulse Width Modulation (PWM)
• Pulse Amplitude Modulation (PAM)
• Pulse Position Modulation (PPM)
Pulse Code Modulation (PCM)
Pulse Width Modulation (PWM)
Sometimes called as Pulse Duration Modulation (PDM) or Pulse Length Modulation (PLM)
In this method, the width of the constant amplitude pulse varies proportionally with the amplitude of the analog signal at time the signal is sampled.
Pulse Position Modulation (PPM)
In this method, the position of a constant-width pulse within a prescribed time slot is varied according to the amplitude of the sample of the analog signal.
Pulse Ampitude Modulation (PAM)
In this method, the amplitude of a constant width, constant-position pulse is varied according to the amplitude of the sample of the analog signal.
Pulse Code Modulation (PCM)
In this method, the analog signal is sampled and then converted to a serial n-bit binary code for transmission. Each code has the same number of bits and requires the same length of time for transmission.
Graph of each Pulse Modulation Method
Uses
Definition:
Transmittal of digital signals between two or more points in a communications system.
Advantages of Digital Transmission
• Noise immunity
• Ease of processing and combining
• Ease of measuring and evaluating
•
Disadvantages of Digital Transmission
• Requires more bandwidth
• Necessitates encoding and decoding circuitry
• Requires precise time synchronization
• Incompatible with older analog transmission systems
Pulse Modulation
Pulse Modulation consists essentially of sampling analog information signals and then converting those samples into discrete pulses and transporting the pulses from a source to a destination over a physical transmission medium.
Pulse Modulation is a method of modulation that represents information as a train of pulses, wherein one or more characteristics of each pulse change with the input signal's variation.
Methods of Pulse Modulation
• Pulse Width Modulation (PWM)
• Pulse Amplitude Modulation (PAM)
• Pulse Position Modulation (PPM)
Pulse Code Modulation (PCM)
Pulse Width Modulation (PWM)
Sometimes called as Pulse Duration Modulation (PDM) or Pulse Length Modulation (PLM)
In this method, the width of the constant amplitude pulse varies proportionally with the amplitude of the analog signal at time the signal is sampled.
Pulse Position Modulation (PPM)
In this method, the position of a constant-width pulse within a prescribed time slot is varied according to the amplitude of the sample of the analog signal.
Pulse Ampitude Modulation (PAM)
In this method, the amplitude of a constant width, constant-position pulse is varied according to the amplitude of the sample of the analog signal.
Pulse Code Modulation (PCM)
In this method, the analog signal is sampled and then converted to a serial n-bit binary code for transmission. Each code has the same number of bits and requires the same length of time for transmission.
Graph of each Pulse Modulation Method
Uses