This textbook introduces the transmission of digital signals over disturbed channels, emphasizing an intuitive and mathematically grounded explanation of baseband transmission. It recaps essential fundamentals of signal and system theory and explores functional interdependencies in baseband transmission to advance the understanding of baseband transmission concepts. The wired transmission using copper cable is highlighted as an important transmission technique. The copper cable?s transmission characteristics are described using classical electrical engineering and system theory methods. Baseband techniques are applied to the transmission over the linearly distorting channel copper cable, with discussions on filtering and equalization. The textbook includes detailed derivations, numerical examples, solved exercises and various illustrations.