Shannoni kanali võimsuse teoreem

Intuitively, channel capacity answers the question: how much information can I transmit per unit time reliably despite noise? Shannon showed that the answer depends on three factors: (1) bandwidth B (more bandwidth -> more capacity), (2) signal power S (stronger signal -> more capacity), and (3) noise power N (less noise -> more capacity). The logarithmic trade-off log2(1 + S/N) captures a deep truth: doubling power only increases capacity by 1 bit/s/Hz, a diminishing return. This explains why, despite centuries of communication practice, reliable communication is fundamentally limited until the ratio of signal to noise is sufficiently high. It also motivates sophisticated modulation and coding: they approach capacity asymptotically but never exceed it.