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SRI RAMAKRISHNA ENGINEERING COLLEGE
[Educational Service: SNR Sons Charitable Trust]
[Autonomous Institution, Reaccredited by NAAC with ‘A+’ Grade]
[Approved by AICTE and Permanently Affiliated to Anna University, Chennai]
[ISO 9001:2015 Certified and all eligible programmes Accredited by NBA]
Vattamalaipalayam, N.G.G.O. Colony Post, Coimbatore – 641 022.
DEPARTMENT OF SCIENCE AND HUMANITIES
(MATHEMATICS)
Dr.R.Kasthuri
Associate Professor
Department of Mathematics
Sri Ramakrishna Engineering College
Role of Probability in Signal
Processing & Wireless
Communication
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•The Core Problem: Real-world signals and transmission channels are inherently
corrupted by random, unpredictable variations.
•Probability Models: We use probability distributions to capture this randomness,
turning unpredictable physical phenomena into quantifiable mathematical models.
• Key Definitions:
PDF (Probability Density Function): Defines the likelihood of a continuous
random variable (e.g., noise voltage, signal phase).
PMF (Probability Mass Function): Defines the likelihood of a discrete random variable
(e.g., digital bits, number of users).
CDF (Cumulative Distribution Function): The probability that a random variable
takes a value less than or equal to a specific value.
Overview & Core Concepts
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Geometric Distribution- Discrete Time Failure,
Retransmission and Search Dynamics.
• Models the number of discrete, independent Bernoulli trials (0 or 1)
required to achieve the first success.
• Retransmission Mechanics: Forms the exact foundation for ARQ
(Automatic Repeat reQuest) protocols by predicting how many
packet transmission attempts it takes to bypass channel noise.
• Directly calculates the exact battery power depletion of remote IoT sensors by
mapping the number of random-access channel attempts needed to establish a
connection.
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Gaussian (Normal) Distribution-
Modeling Thermal Noise & System Interference
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Uniform distribution-Role in Signal Processing and Wireless Communication
• Uniform distributions are useful for modeling random signals and
errors where all values in a particular range are equally likely.
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Exponential distribution-Role in Signal Processing and Wireless
Communication
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