The undetectability of a wireless covert channel should be benchmarked under noisy channel
with a range of noise SNRs.
They prove that in traditional systems the channel converges to a Gaussian noisy channel
in the limit in the case of almost any jamming signal, and in our new ideal modified system the channel converges to a white Gaussian noisy channel
in the limit in the case of any jamming signal when the processing gain goes to infinity .
Challenges Reason(s) Path loss Geometric spreading/Energy loss Shadowing Random distribution of objects in 3D space Noisy channel
Human made noise/Ambient noise/Other noises Hard channel fading Multipath Inter-Symbol -Interference (ISI) High communication rate in low bandwidth Non-fixed delay Non-fixed speed of carrier wave Doppler shift Non-fixed frequency of carrier wave Challenges Effect(s) Path loss Low bandwidth/Low data rate Shadowing Low bandwidth/Low data rate Noisy channel
Low data rate (Hard detection) Low data rate Hard channel fading (Hard detection) Inter-Symbol -Interference (ISI) Low data rate (Hard detection) Non-fixed delay Low data rate (Hard detection) Doppler shift Low data rate (Hard detection) Table 4.
"Leti's Turbo-FSK receiver performs close to the Shannon limit, which is the maximum rate that data can be transmitted over a given noisy channel
without error, and is geared for low spectral efficiency," said Vincent Berg, head of Leti's Smart Object Communication Laboratory.
Bennett and his coworkers have now shown that it's possible to send these photons through a noisy channel
, which corrupts their quantum states, and still recover useful information.
Due to code redundancy, the main disadvantage of all HARQ schemes is the throughput in less noisy channel
, which is significantly lower than the throughput of pure ARQ.
In regard to the number of samples, the only relationship arises from taking a large number of samples, which increases the consumption as the node keeps in the noisy channel
for too long.
Performance evaluation criteria of RS coded OFDM transmission over noisy channel
. International Journal of Soft Computing and Engineering (IJSCE), 1(3): 24-28.
The signal may be of studio quality or may have been transmitted over a telephone or other noisy channel
(that is, corrupted by additive noise and nonlinear distortions), or can contain speech over music or pure music segments.
The second result is the Channel Coding Theorem, which determines the maximum amount of information that can be sent through a noisy channel
. Efficient coding schemes for use in noisy channels
are implemented by the use of redundancies.