What is fade margin & how it is calculated?
Adjacent channel interference fade margin is calculated as the difference between the median signal level and the total adjacent channel interference level, minus the required desired carrier-to-adjacent channel interference level to achieve acceptable performance.
What is a good fade margin?
A fade margin of 10 dB is an absolute minimum. This would only be acceptable for links less than 3 miles or so. Up to 5 miles should have at least a 15 dB fade margin, and links greater than that should be higher. A fade margin of 25 dB is recommended for links greater than 5 miles.
What is fading margin and receiver sensitivity?
Fade Margin is an expression for how much margin – in dB – there is between the received signal strength level and the receiver sensitivity of the radio. The figure below describes the term fade margin. Site A is transmitting with 33dBm (2W) power.
What is the difference between fading and shadowing?
Fading is a significant part of any wireless communication design and is important to model and predict accurately. Large scale shadowing, on the other hand, is very dependent on location with respect to obstacles; its modeling often consists in predicting the likelihood of outage.
How do I increase my fade margin?
First, what is fade margin?
- Increase antenna height to get the antenna above obstacles.
- Select antennas with higher gain.
- Reduce the radio data rate to get better receiver sensitivity.
- Add a repeater between the sites.
Why do we need fading margin?
The level of received power in excess of that required for a specified minimum level of system performance is referred to as the fade margin. So called, because it provides a margin of safety in the event of a temporary attenuation or fading of the received signal power.
What is fading margin in wireless communication?
In telecommunication, the term fade margin (fading margin) has the following meanings: A design allowance that provides for sufficient system gain or sensitivity to accommodate expected fading, for the purpose of ensuring that the required quality of service is maintained.
What are the types of fading?
1.) Large Scale Fading
- a) Path loss. The free space path loss can be expressed as follows.
- b) Shadowing effect. •
- a) Flat fading.
- b) Frequency Selective fading.
- c) Fast fading.
- d) Slow fading.
- Rayleigh fading.
- Rician fading.
What are the main reasons for path losses?
Path loss normally includes propagation losses caused by the natural expansion of the radio wave front in free space (which usually takes the shape of an ever-increasing sphere), absorption losses (sometimes called penetration losses), when the signal passes through media not transparent to electromagnetic waves.
How many types of fading are there?
There are two types of fading viz. large scale fading and small scale fading.
What is fading explain?
In Wireless Communication, fading refers to the attenuation of the transmitted signal power due to various variables during wireless propagation. Fading can cause decline in performance in a wireless communication system because it results in the loss of signal power thus reducing the Signal to Noise Ratio (SNR).
What is short term fading?
The short-term variation is due to multipath fading and can be described by either Rician or Nakagami distribution, and the long-term fading usually follows a log-normal, or gamma distribution. The rates of fading expressed in terms of level crossing rate and average fade duration have been also obtained.
What is “fade margin”?
Fade Margin is an expression for how much margin – in dB – there is between the received signal strength level and the receiver sensitivity of the radio. The figure below describes the term fade margin. Site A is transmitting with 33dBm (2W) power. After the distance to the site B, the signal level has dropped to -100dBm.
What is the fade margin of a radio signal?
The figure below describes the term fade margin. Site A is transmitting with 33dBm (2W) power. After the distance to the site B, the signal level has dropped to -100dBm. This gives a margin of -10 dBm since the receiver sensitivity of the radio at site b is -110 dBm.
What are the different types of small scale fading?
Small scale fading is concerned with rapid fluctuations of received signal strength over very short distance and short time period. Based on multipath delay spread there are two types of small scale fading viz. flat fading and frequency selective fading. These multipath fading types depend on propagation environment. 2.a) Flat fading
What is the difference between fast fading and slow fading?
Fast fading distorts the shape of the baseband pulse. This distortion is linear and creates ISI (Inter Symbol Interference). Adaptive equalization reduces ISI by removing linear distortion induced by channel. Slow fading is result of shadowing by buildings, hills, mountains and other objects over the path.