Lives of humans are related to each other. Initially, the most challenging task for a man was to put forth his thoughts. It was impossible to convey one`s thoughts through gestures and body language thus words were invented. Thoughts can be portrayed in the form of words using language, though it is not very efficient; it has become a basic necessity for everyone to use it. But when humans started to explore the world, more knowledge was discovered which was to be shared, and, texts and speech alone became insufficient …show more content…
Our planet started shrinking as the world of communication began to expand. But none of these changed the destiny of humankind as much as what James Clerk Maxwell`s discovery did. Limitations were redefined by electro-magnetic waves; it made wireless communication possible.
2.2 Wireless Communication
EM waves are used by wireless communication to transfer data between two users. Wireless communication is considered as the key element of modern society. Wireless communications have revolutionized the way societies function, from radio and television broadcasting, satellite transmission to now ubiquitous mobile phones. Wireless communication has many more advantages as compared to the earlier successful wired communication: These are because of its portability, flexibility, and coverage.
The freedom a hand-held device like a cell phone offers the user is portability. The ability to add/remove device into existing networks without any changes in hardware is flexibility. Technologies such as cellular radio enable users to move over a large area providing them …show more content…
A channel (free space, buildings, etc.) is used for the propagation of these waves. Various distortions are introduced into the signal during these propagations. The receiver receives this signal is received by the receiver. In order to successfully interpret the message, the receiver needs to know about the nature of discrepancies introduced by the channel. Channel Estimation is the process of evaluating the way a circuit behaves to EM waves.
Wireless communication needs channel estimation to counter the effects of thechannel on the signal. The variations of the channel strength over time and over frequency are the defining characteristics of the wireless channel. There are two types of changes:
1. Large-scale fading, due to path loss of signal as a function of distance and shadowing by large objects such as buildings and