Search results
Results from the WOW.Com Content Network
In telecommunications, the term channel noise level has the following meanings: The ratio of the noise in the communication channel at any point in a transmission system to an arbitrary level chosen as a reference. [a] [b] The noise power spectral density in the frequency range of interest. The average noise power in the frequency range of ...
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.
English: pdf Version of english wikibook on Communication Systems This file was created with MediaWiki to LaTeX . The LaTeX source code is attached to the PDF file (see imprint).
/ must be used with care on interference-limited channels since additive white noise (with constant noise density ) is assumed, and interference is not always noise-like. In spread spectrum systems (e.g., CDMA), the interference is sufficiently noise-like that it can be represented as and added to the thermal noise to produce the overall ratio
SNR is an important parameter that affects the performance and quality of systems that process or transmit signals, such as communication systems, audio systems, radar systems, imaging systems, and data acquisition systems. A high SNR means that the signal is clear and easy to detect or interpret, while a low SNR means that the signal is ...
In the simple version above, the signal and noise are fully uncorrelated, in which case + is the total power of the received signal and noise together. A generalization of the above equation for the case where the additive noise is not white (or that the / is not constant with frequency over the bandwidth) is obtained by treating the channel as many narrow, independent Gaussian ...
The basic mathematical model for a communication system is the following: Communication with feedback. Here is the formal definition of each element (where the only difference with respect to the nonfeedback capacity is the encoder definition): is the message to be transmitted, taken in an alphabet;
where is the overall noise factor of the subsequent stages. According to the equation, the overall noise factor, , is dominated by the noise factor of the LNA, , if the gain is sufficiently high. The resultant Noise Figure expressed in dB is: