Channel Coefficients and Path Loss

[mish111990]

hi,

im trying to model a rayleigh fading channel with AWGN for a hybrid relay forwarding scheme.

i have generated the channel coefficients then it hit me that I didn't include any measure for the path loss as the signal propagates.

i am using matlab and generated the coefficients (h) and noise using pre-built functions.
(y = h*x + n)

i also have a distance parameter but I don't know how to include the path loss factor as the signal travels from the BS to the MS.

Is path loss already within the coefficients?

 

[albbg]

I don't think your coefficients also include the path losses. They should only take into account the variation of the path loss due to the fading.
As a simple approach, applicable only to pure LOS connections, you can apply the formula PathLoss(dB) = -27.6 + n*log10(f*d) where f=frequency in MHz, d=distance in meters, n=coefficient (20 outdoor, roughly 35 indoor).
For more complex models (urban areas, NLOS, indoor applications) you can refer to the standard COST-231.

 

[mish111990]

thanks for the reply. so by the COST-231 do u mean the COST Hata Model.

Hata Model for Urban Areas - Wikipedia, the free encyclopedia

i notice that the path loss will be in dB. so if i have the snr(dB) at the receiver, do i just subtract the path loss from it provided the snr is calculated using the channel coefficitents?

 

[albbg]

Yes, I ment Okumura-Hata Model.
In a TX-RX system generally you know the transmitter output power Ptx, the gain of the two antennas receiving and trasmitting Gtx and Grx, the total losses in the cable Lc and the sensitivity at receiver side Prx. If no other interfer is present then, in order to receive the signal must be:

Prx > Ptx + Gtx + Grx - Lc - PathLoss all of them in dB

 

[comp04]

Hi,
Can Hata Model be used in wireless sensor actor networks with mobile actors in Urban areas?

 

[robintane]

Hi

Please show me how to include path loss factor to this form : (y = h*x + n)

Thank you

 

[Egens]

hi,

im trying to model a rayleigh fading channel with AWGN for a hybrid relay forwarding scheme.

i have generated the channel coefficients then it hit me that I didn't include any measure for the path loss as the signal propagates.

i am using matlab and generated the coefficients (h) and noise using pre-built functions.
(y = h*x + n)

i also have a distance parameter but I don't know how to include the path loss factor as the signal travels from the BS to the MS.

Is path loss already within the coefficients?

Hi Mish
How did u generate the H and n using inbuilt functions of the mathlab?

- - - Updated - - -

Hi

Please show me how to include path loss factor to this form : (y = h*x + n)

Thank you

Hi Robintane,
I have similar problem. have you got a solution yet?