Search results
Results from the WOW.Com Content Network
This led to the adoption of interference alignment in the design of wireless networks. [3] Jafar explained: My research group crystallized the concept of interference alignment and showed that through interference alignment, it is possible for everyone to access half of the total bandwidth free from interference.
One of the causes of intersymbol interference is multipath propagation in which a wireless signal from a transmitter reaches the receiver via multiple paths. The causes of this include reflection (for instance, the signal may bounce off buildings), refraction (such as through the foliage of a tree) and atmospheric effects such as atmospheric ducting and ionospheric reflection.
Fig. 1: Underwater plants in a fish tank, and their inverted images (top) formed by total internal reflection in the water–air surface. In physics, total internal reflection (TIR) is the phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into ...
In communications, the Nyquist ISI criterion describes the conditions which, when satisfied by a communication channel (including responses of transmit and receive filters), result in no intersymbol interference or ISI. It provides a method for constructing band-limited functions to overcome the effects of intersymbol interference.
Telecommunication systems strive to increase the ratio of signal level to noise level in order to effectively transfer data. Noise in telecommunication systems is a product of both internal and external sources to the system. Noise is a random process, characterized by stochastic properties such as its variance, distribution, and spectral density.
Hence, the different senders can have a possible crosstalk or co-channel interference on the signal of each other. The inter-cell interference in cellular wireless communications is an example of an interference channel. In spread-spectrum systems like 3G, interference also occurs inside the cell if non-orthogonal codes are used.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Every signaling system can be characterized along each of the above axes of classification. A few examples: DTMF is an in-band, channel-associated register signaling system. It is not compelled. SS7 (e.g., TUP or ISUP) is an out-of-band, common-channel signaling system that incorporates both line and register signaling.