Recommended for undergraduate exam preparation in the Indian education system. For self-learning, industry work, or research, supplement it heavily with a more intuitive text (like Smith or Lyons). Do not pirate it; buy a used copy or the cheap e-book.
This response is structured for students, engineers, and academics looking for a legitimate, high-quality resource on DSP. Full Title: Digital Signal Processing Author: Tarun Kumar Rawat (Generally associated with Oxford University Press, India) Target Audience: Undergraduate (B.Tech/B.E.) and Postgraduate (M.Tech) students in Electronics & Communication Engineering (ECE), Electrical Engineering (EE), and Computer Science (CS). Tarun Kumar Rawat Digital Signal Processing Download
Go to Google Books or Amazon India, search "Digital Signal Processing Tarun Kumar Rawat", and click "Buy E-book" (approx. ₹350-500). Then, download the free MATLAB or Octave software to practice the examples. Recommended for undergraduate exam preparation in the Indian