Are these Digital Signal Processing handwritten notes free?

Yes. Fill in the short form on this page and the PDF downloads right away. There is no fee for the notes.

Are these official university notes?

No. These are original Uncodemy revision notes for Digital Signal Processing. They are not issued or approved by AKTU or any other university, and they are not past papers.

Which syllabus do they follow?

They follow the common B.Tech syllabus for Digital Signal Processing used by most Indian universities, including AKTU and colleges on the AICTE model curriculum. Unit order and depth differ, so match the notes with your own university syllabus.

Should I study Signals and Systems before DSP?

Yes. DSP builds on convolution, the Fourier transform and the Z-transform from Signals and Systems. Revise those notes first if they are weak.

Is filter design included?

Yes. There are separate units for IIR filter design (Butterworth, Chebyshev, impulse invariance and bilinear transform) and FIR filter design using windows.

Digital Signal Processing Handwritten Notes PDF

Key takeaways

Nine units, from DTFT and DFT to decimation and interpolation.
A 4-point DFT and a circular convolution are solved step by step.
Radix-2 FFT is explained with bit reversal and the saving in multiplications.
IIR design by impulse invariance and bilinear transform, and FIR design by windows, are compared.
Original Uncodemy revision notes, not official university notes. Check your own syllabus.

About these handwritten notes

These Digital Signal Processing notes are original Uncodemy revision notes, written in a clean handwritten style so they are quick to read before an exam. They follow the common B.Tech syllabus for Digital Signal Processing (B.Tech ECE and EEE, and GATE EC basics). They are not official university notes and not copied from any textbook or past paper.

Topic order, unit numbers and depth vary between universities, so first place each unit below against your own university syllabus. If your syllabus has a topic that is missing here, add it in the margin from your class notes or textbook. Use these notes for revision after you have studied the topic once in class, not as your only study material. They are short on purpose: the aim is to help you recall the main ideas, formulas and diagrams quickly, so that your exam time goes into writing good answers.

What's inside the Digital Signal Processing notes

The notes start with a short recap of discrete-time systems and then move to transforms and filter design. Each unit has worked examples and a short exam tip.

Unit 1: Introduction. DSP compared with analog processing, and a recap of discrete-time signals and systems.
Unit 2: DTFT. Definition, periodicity and key properties of the discrete-time Fourier transform.
Unit 3: Discrete Fourier Transform (DFT). DFT and IDFT, properties, circular vs linear convolution, and overlap-add and overlap-save for long sequences.
Unit 4: Fast Fourier Transform (FFT). Radix-2 decimation in time and frequency, butterfly diagrams, bit reversal and computational saving.
Unit 5: IIR Filter Design. Butterworth and Chebyshev analog prototypes, impulse invariance, bilinear transformation and frequency warping.
Unit 6: FIR Filter Design. Linear phase, the window method, common windows and an FIR vs IIR comparison.
Unit 7: Filter Structures. Direct form I and II, cascade, parallel and lattice structures.
Unit 8: Finite Word Length Effects. Coefficient quantisation, round-off noise and limit cycles.
Unit 9: Multirate DSP. Decimation, interpolation and their effect on the spectrum.

The last page of the PDF lists the most asked practice questions for the whole subject, so you can test yourself after finishing all the units.

Formulas and solved examples in the PDF

Formula boxes cover the DFT and IDFT, the twiddle factor, FFT multiplication counts, the bilinear mapping s = (2/T)(1 - z⁻¹)/(1 + z⁻¹), pre-warping and window equations. Solved examples include a 4-point DFT, a circular convolution, the FFT saving over direct DFT, and the bit-reversed input order for an 8-point FFT.

How to revise Digital Signal Processing with handwritten notes

Handwritten-style notes work best when you read actively. Keep a pen and a rough notebook beside you, cover the formula or diagram, and try to write it yourself before you look.

Practise one 4-point DFT by hand every revision session. It builds speed for twiddle factor values.
Draw the 8-point DIT butterfly once from memory and check the bit-reversed input order against the notes.
For IIR design, write the full design steps as a checklist: specifications, prewarp, order, poles, analog TF, then digital TF.
Make one table for FIR vs IIR and one for the four types of linear phase FIR filters.

In the last week, read only the formula boxes and exam tips, and solve one numerical or long question per unit from memory. If you study with friends, ask each other to explain one diagram or derivation aloud. Explaining a topic is the fastest way to find the gaps in it.

A short revision plan

If your exam is about a week away, this plan covers every unit in the PDF once and leaves time for practice. Stretch it over two weeks if you are starting from scratch.

Day 1: Introduction, DTFT.
Day 2: Discrete Fourier Transform (DFT), Fast Fourier Transform (FFT).
Day 3: IIR Filter Design, FIR Filter Design.
Day 4: Filter Structures, Finite Word Length Effects.
Day 5: Multirate DSP.
Day 6: Solve the practice questions in the exam focus section below, one per unit, without the notes.
Day 7: Read only the formula boxes and exam tips, redo the numericals you got wrong, and sleep early.

Common mistakes to avoid

Doing circular convolution when the question asks for linear convolution. Zero-pad both sequences to length N1 + N2 - 1 first.
Skipping pre-warping when designing with the bilinear transform. The digital band edges will then be wrong.
Getting the twiddle factor sign wrong in the IDFT. The IDFT uses the positive exponent and a 1/N factor.
Using impulse invariance for a high pass filter. It suffers from aliasing, so the bilinear transform is preferred.

How Digital Signal Processing links to other subjects

Digital Signal Processing builds on Signals and Systems, especially convolution, the Fourier transform and the Z-transform. It leads into image processing, speech and audio processing, digital communication receivers and machine learning on signal data.

Exam focus: high-weightage topics

University papers usually give the most weight to the DFT and its properties, circular convolution, the FFT flow graph, IIR design with the bilinear transform and FIR design with windows. Filter structures are a common short or medium question.

Typical long and numerical questions to practise:

Find the 4-point and 8-point DFT of a sequence.
Find linear convolution using circular convolution with zero padding.
Draw the 8-point radix-2 DIT FFT flow graph and count multiplications.
Compare impulse invariance and bilinear transformation, and explain frequency warping.
Design a Butterworth low pass digital filter using the bilinear transform.
Design a linear phase FIR low pass filter using the Hamming window.

When you write a long answer, start with a one-line definition, draw the diagram or circuit, write the derivation in clear steps and end with the final result and its unit. For numericals, write the formula first, then substitute, so you can still earn step marks if the arithmetic slips.

These are practice questions based on common syllabus topics. They are not verified past papers, and we do not claim any question will appear in your exam. For real previous papers, use your university's official archive.

Who these notes are for

These notes are for B.Tech ECE and EEE students preparing for their Digital Signal Processing semester exam, and for students revising GATE EC basics such as DFT values, circular convolution and FFT counts. They are also a good base for students moving towards audio, image processing or machine learning work, where DSP ideas are used every day.

Download Digital Signal Processing Handwritten Notes PDF