From Wikipedia, we know that in signal processing, a signal is a function that conveys information about a phenomenon. In the transmission of information, a signal can be audio, video, image and other human cognitive representations. In the information theory, these representations could be encoded into signals and then these signals can be transmitted through channel. During the transmission in the channel, there is some noises which could lower the quality of transmission. A certain level of redundancy helps in ensuring that most of codes could reach decoder. The next step is that the decoder of the receiver will decode the codes. The “original” information will be rebuilt after decode process.
Why the signal-code-transmission model is not a description of meaning? In my opinion, the first reason is that humans don’t interact with this transmission process directly. It’s our cognitive representations that are encoded, transmitted and decoded in this process. With the codes only, we can’t understand its meaning, which is different from any other agencies in society and culture. Second, this model’s function is achieved by machines and machines’ work even plays a more important role than the meaning they carry. If the encoder, channel and decoder don’t work well, the information will be distorted.
The reason why the information theory is essential for everything electronic and digital is that they rely on information theory to achieve their meaning. The electronic and digital devices need to receive signal to perform some functions, especially the smarter electronic digital devices, like computer and mobile phone. Different devices’ cooperation depends on the information theory. Code is a common language in these devices. By the encode-decode process, code could be transported in channels to different devices. It’s safe to say that the information theory makes electronic and digital devices more powerful.
In my perspective, the information theory serves as an auxiliary in human social meaning system. It surely enhances our ability in transmission and representation of the cognitive issues. However, does it improve our meaning in the these signals? No. Even worse, the noise might damage codes during the transmission in channel. Another reason is that humans don’t use code to communicate with each other directly. Therefore, this theory actually helps a lot in transmission, but it could not be used to expand our sign and symbol systems.
Martin Irvine, Introduction to the Technical Theory of Information (read first)
Luciano Floridi, Information: A Very Short Introduction. Oxford, UK: Oxford University Press, 2010. Read Chapters 1-4. Excerpts.