What causes slow fading?
Slow fading can be caused by events such as shadowing, where a large obstruction such as a hill or large building obscures the main signal path between the transmitter and the receiver.
What is channel capacity of fading channel?
The capacity of the fading channel is the sum of the capacities in each fading state weighted by the probability of that state.
What causes channel fading?
Fading occurs due to multiple paths between the transmitter and receiver. For example, two paths between the transmitter and receiver with approximately the same delay and amplitude but opposite phase (180 degree phase shift) will cause the signal amplitude to be essentially zero.
What is the condition for fast fading?
Fast Fading: It occurs mainly due to reflections for surfaces and movement of transmitter or receiver. High doppler spread is observed in the fast fading with Doppler bandwidth comparable to or greater than the bandwidth of the signal and the channel variations are as fast or faster than the signal variations.
What is meant by slow fading channel?
In slow fading channels, the coherence time of the channel is long and encoding can be performed only over a single or a few fading states (e.g., time diversity). While encoding still averages out the randomness of the noise, it may not be possible to fully average out the randomness of the channel.
What is slow fading and fast fading?
Fading refers to variation in signal strength with respect to time as it is received at the antenna from the transmitter at distant end. The variation can be result of communication channel between the transmitter and receiver. The figure depicts both fast fading and slow fading amplitude versus distance curve.
What is channel capacity and bandwidth?
It is measured in bits per second (bps). Channel capacity is a rough value as measuring takes into account only the whole amount of data transferred, but leaves out of account communication quality. Bandwidth can be considered as a subset of channel capacity term.
How can slow fading be minimized?
Explanation: Slow fading can be minimized by using error correcting codes and also by using diversity technique to get additional uncorrelated estimates of a signal.
What is fast and slow fading in wireless communication?
It originates due to effect of mobility. It is result of signal path change due to shadowing and obstructions such as tree or buildings etc. Slow fading refers to changes in signal strength between a transmitter and receiver as the distance between the two changes by a larger distance, well in excess of a wavelength.
Is capacity the same as bandwidth?
Typically, bandwidth is represented in the number of bits, kilobits, megabits or gigabits that can be transmitted in 1 second. Synonymous with capacity, bandwidth describes data transfer rate.
How is channel related to bandwidth?
Communication channels are classified as analog or digital. Bandwidth refers to the data throughput capacity of any communication channel. As bandwidth increases, more information per unit of time can pass through the channel. A simple analogy compares a communication channel to a water pipe.
How does bandwidth affect channel capacity?
Bandwidth can be considered as a subset of channel capacity term. When bandwidth is measured, the maximum volume of information that can be accurately transferred per unit of time is taken into account. For example, channel capacity may be very high, but low signal quality would make bandwidth low as well.
What is fading channel and their characteristics?
Fading. Fast fading refers to the rapid fluctuations in the amplitude, phase or multipath delays of the received signal, due to the interference between multiple versions of the same transmitted signal arriving at the receiver at slightly different times.
What is channel capacity?
The channel capacity, C, is defined to be the maximum rate at which information can be transmitted through a channel. The fundamental theorem of information theory says that at any rate below channel capacity, an error control code can be designed whose probability of error is arbitrarily small.
What will affect channel capacity?
Channel Capacity Channel capacity of the wireless underground channel depends on the soil moisture, operation frequency, and bandwidth of the antenna. Impact of different factors on the channel capacity are shown in the following.
Is capacity and bandwidth the same?
Typically, bandwidth is represented in the number of bits, kilobits, megabits or gigabits that can be transmitted in 1 second. Synonymous with capacity, bandwidth describes data transfer rate. Bandwidth is not a measure of network speed — a common misconception.
What is channel capacity in bandwidth?
Channel capacity is a maximum information rate that a channel can transmit. It is measured in bits per second (bps). Channel capacity is a rough value as measuring takes into account only the whole amount of data transferred, but leaves out of account communication quality.
What is the-outage capacity of a slow fading channel?
If the transmitter encodes data at rate in which case the system is said to be in outage. With a non-zero probability that the channel is in deep fade, the capacity of the slow-fading channel in strict sense is zero. However, it is possible to determine the largest value of . This value is known as the -outage capacity.
What is flat fading in wireless communication?
2.a) Flat fading. The wireless channel is said to be flat fading if it has constant gain and linear phase response over a bandwidth which is greater than the bandwidth of the transmitted signal. In this type of fading all the frequency components of the received signal fluctuate in same proportions simultaneously.
What is the difference between slow fading and encoding?
In slow fading channels, the coherence time of the channel is long and encoding can be performed only over a single or a few fading states (e.g., time diversity). While encoding still averages out the randomness of the noise, it may not be possible to fully average out the randomness of the channel.
What is fast fading in signal processing?
When the signals arrive from all the directions in the plane, fast fading will be observed for all directions of motion. Fast fading occurs when channel impulse response changes very rapidly within the symbol duration.