Signal Processing for Communication Systems
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Keyfocus: Fading channel models for simulation. Learn how fading channels can be modeled as FIR filters for simplified modulation & detection. Rayleigh/Rician fading. Introduction A fading channel is a wireless communication channel in which the quality of the signal fluctuates over time due to changes in the transmission environment. These changes can be caused by … Read more
Central Limit Theorem – What is it ? The central limit theorem (CLT) is a fundamental concept in statistics and probability theory that explains how the sum of independent and identically distributed random variables behaves. The theorem states that as the number of these variables increases, the distribution of their sum tends to become more … Read more
Keywords: maximum likelihood estimation, statistical method, probability distribution, MLE, models, practical applications, finance, economics, natural sciences. Introduction Maximum Likelihood Estimation (MLE) is a statistical method used to estimate the parameters of a probability distribution by finding the set of values that maximize the likelihood function of the observed data. In other words, MLE is a … Read more
Keywords: maximum likelihood decoding, digital communication, data storage, noise, interference, wireless communication systems, optical communication systems, digital storage systems, probability, likelihood estimation, python Introduction Maximum likelihood decoding is a technique used to determine the most likely transmitted message in a digital communication system, based on the received signal and statistical models of noise and interference. … Read more
What are hard and soft decision decoding Hard decision decoding and soft decision decoding are two different methods used for decoding error-correcting codes. With hard decision decoding, the received signal is compared to a set threshold value to determine whether the transmitted bit is a 0 or a 1. This is commonly used in digital … Read more
Its been too long since I posted. For a kick start ,i am continuing the theory on RS coding.Here is a simple Matlab code (which can be found in Matlab Help, posted here with a little bit detailed explanation) for better understanding of RS code %Matlab Code for RS coding and decoding n=7; k=3; % … Read more
The Hamming codes described in the previous articles are suitable for random bit errors in a sequence of transmitted bits. If the communication medium is prone to burst errors (channel errors affecting contiguous blocks of bits) (missing symbols are called erasures ), then Hamming code may not be suitable. For example in CD, DVD and … Read more
Keywords: Hamming code, error-correction code, digital communication, data storage, reliable transmission, computer memory systems, satellite communication systems, single-bit error, two-bit errors. What is a Hamming Code Hamming codes are a class of error-correcting codes that are commonly employed in digital communication and data storage systems to detect and correct errors that may occur during transmission … Read more
Shannon theorem dictates the maximum data rate at which the information can be transmitted over a noisy band-limited channel. The maximum data rate is designated as channel capacity. The concept of channel capacity is discussed first, followed by an in-depth treatment of Shannon’s capacity for various channels. Introduction The main goal of a communication system … Read more
Random Variable: In a “coin-flipping” experiment, the outcome is not known prior to the experiment, that is we cannot predict it with certainty (non-deterministic/stochastic). But we know the all possible outcomes – Head or Tail. Assign real numbers to the all possible events (this is called “sample space”), say “0” to “Head” and “1” to … Read more