Digital Signal Processing Tutorial
Operations on Signals
Basic System Properties
Z-Transform
Discrete Fourier Transform
Fast Fourier Transform
Digital Signal Processing Resources
Selected Reading
- DSP - Miscellaneous Signals
- DSP - Classification of DT Signals
- DSP - Classification of CT Signals
- DSP - Basic DT Signals
- DSP - Basic CT Signals
- DSP - Signals-Definition
- DSP - Home
Operations on Signals
- Operations Signals - Convolution
- Operations Signals - Integration
- Operations Signals - Differentiation
- Operations Signals - Reversal
- Operations Signals - Scaling
- Operations Signals - Shifting
Basic System Properties
- DSP - Solved Examples
- DSP - Unstable Systems
- DSP - Stable Systems
- DSP - Time-Variant Systems
- DSP - Time-Invariant Systems
- DSP - Non-Linear Systems
- DSP - Linear Systems
- DSP - Anti-Causal Systems
- DSP - Non-Causal Systems
- DSP - Causal Systems
- DSP - Dynamic Systems
- DSP - Static Systems
Z-Transform
- Z-Transform - Solved Examples
- Z-Transform - Inverse
- Z-Transform - Existence
- Z-Transform - Properties
- Z-Transform - Introduction
Discrete Fourier Transform
- DFT - Solved Examples
- DFT - Discrete Cosine Transform
- DFT - Sectional Convolution
- DFT - Linear Filtering
- DTF - Circular Convolution
- DFT - Time Frequency Transform
- DFT - Introduction
Fast Fourier Transform
Digital Signal Processing Resources
Selected Reading
- Who is Who
- Computer Glossary
- HR Interview Questions
- Effective Resume Writing
- Questions and Answers
- UPSC IAS Exams Notes
DSP - Time-Variant Systems
DSP - Time-Variant Systems
For a time variant system, also, output and input should be delayed by some time constant but the delay at the input should not reflect at the output. All time scapng cases are examples of time variant system. Similarly, when coefficient in the system relationship is a function of time, then also, the system is time variant.
Examples
a) $y(t) = x[cos T]$
If the above signal is first passed through the system and then through the time delay, the output will be $xcos (T-t)$. If it is passed through the time delay first and then through the system, it will be $x(cos T-t)$. As the outputs are not same, the system is time variant.
b) $y(T) = cos T.x(T)$
If the above expression is first passed through the system and then through the time delay, then the output will be $cos(T-t)x(T-t)$. However, if the expression is passed through the time delay first and then through the system, the output will be $cos T.x(T-t)$. As the outputs are not same, clearly the system is time variant.
Advertisements