Simulation of Rayleigh Fading ( Clarke’s Model – sum of sinusoids method)

A multipath fading channel  can be modeled as a FIR (Finite Impulse Response) filter with the following impulse response. $$ h( \tau ; t ) = h_{0}(t) \delta ( \tau – \tau_{0}(t)) + h_{1}(t) \delta ( \tau – \tau_{1}(t)) + . . . + h_{L-1}(t) \delta ( \tau – \tau_{L-1}(t)) $$ where h(τ,t) is the … Read more

Correlative Coding – Modified Duobinary Signaling

Modified Duobinary Signaling is an extension of duobinary signaling. It has the advantage of zero PSD at low frequencies (especially at DC ) that is suitable for channels with poor DC response. It correlates two symbols that are 2T time instants apart, whereas in duobinary signaling, symbols that are 1T apart are correlated. The general … Read more

Correlative coding – Duobinary Signaling

The condition for zero ISI (Inter Symbol Interference) is which states that when sampling a particular symbol (at time instant nT=0), the effect of all other symbols on the current sampled symbol is zero. As discussed in the previous article, one of the practical ways to mitigate ISI is to use partial response signaling technique … Read more

Young’s model for Rayleigh fading

Introduction Young’s fading channel model is a mathematical model used to describe the behavior of a wireless communication channel. It is a type of frequency selective fading channel model that is commonly used to simulate the effects of multipath interference on wireless signals. The model is based on the assumption that the transmitted signal reaches … Read more

Fading channel – complex baseband equivalent models

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

Hard and Soft decision decoding

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