Hello, everybody
In the cooperative networks, is the channel coefficient from source to a relay calculated by the equation:
h= sqrt(1 / (D^alpha)) * (1 / sqrt(2)) * (randn + i * randn)
where D is the distance between source to relay in units of meter.
alpha is path loss exponent (normally in the range of 2 and 4)
it depends how each channel behaves between relay and source is distributed. Also type of fading. is it slow fading or fast fading. No of antennas in the source and the realy.
dear sir
In your case you have considered just path loss, we can have fading and multipath, interference impairements, we can say that it will depend on your area and it's up to you to fit it with channel model existing in literature.
Best regards
In cooperative Networks the channel coefficients from source to destination depend upon the path loss and type of fading.
Dear Shan,
Assume you have N transmitters and one receiver.
In the uplink case, where transmitters send to the receiver, there are two general cases:
1) TDMA
2) CDMA
1) In the first case, there is no interference (since each Tx is dedicated a time slot) in which each could transmit alone (i.e. the channel is only dedicated to this transmitter)
Well, in that case you also could choose 2 other models:
1.1) The path loss model. (Your model but without the Gaussian's)
1.2) The Log-Normal Distribution model in which the Log of the 1st model is modelled as Gaussian. This is due to the fact that the environment is rich in multipath and scatterers (thus shadowing).
2) In the second case i.e. CDMA, it may (and usually does) happen that 2 or more transmitters transmit at the same time (i.e. interference). Now, as the name implies, Code Division Multiple Access, lots of codes exist to combat against this type of interference (i.e. Walsh codes, Hadamard Codes, etc..)
Interference and the type of coding is and should be included within the model.
On top of that, you also should include 1.1 or 1.2 ;)
Hope this helps
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