MRC expert - SNR and BER question - need answer

MRC expert

hi all,,

for non identical branch, there are snr for each branch so total snr is summation for all snr in each branch.

what about BER, is it all summation for all BER in each branch, or it is the mean of all branch, or min. BER or what?

i hope to tel me ASAP

thanks

Re: MRC expert

any one help >>>>>>>>>>>>

Re: MRC expert

matlab1983 said:

hi all,,

for non identical branch, there are snr for each branch so total snr is summation for all snr in each branch.

what about BER, is it all summation for all BER in each branch, or it is the mean of all branch, or min. BER or what?

i hope to tel me ASAP

thanks

Click to expand...

If the branches are independent, then the BER is the multiplication of the BER of all branches. For the special case where all branches are independent and indentically distributed, the BER will be \[P^L(E)\], where \[L\] is the number of branches, and \[P(E)\] is the probability of error in each branch.

Re: MRC expert

hi, you can find the BER formulas of MRC in professor Goldsmith "wireless communication" page 199

MRC expert

so in i.n.d ?


do you have paper for this case ?

Added after 2 minutes:

daer insatiable


equation 7.20 for i.id case,
i need for i.n.d ?

Added after 1 hours 13 minutes:

matlab1983 said:

so in i.n.d ?


do you have paper for this case ?

Added after 2 minutes:

daer insatiable


equation 7.20 for i.id case,
i need for i.n.d ?

Click to expand...

Added after 3 hours 14 minutes:

please

i need paper or equation to find total probability of all branches in Rayleigh channel with i.n.d in MRC



since the total SNR is summation for all branches , what about total BER ?


thanks

Added after 34 seconds:

please

i need paper or equation to find total probability of all branches in Rayleigh channel with i.n.d in MRC



since the total SNR is summation for all branches , what about total BER ?


thanks

Re: MRC expert

hi
here is the google book address and you can find the formula you want in there

https://books.google.com/books?id=n...--DsCA&sa=X&oi=book_result&ct=result&resnum=4

Re: MRC expert

Suppose we have \[L\] independent not necessarily identically distributed fading channels between the transmitter and receiver. Employing MRC at the receiver side, the total SNR can be written as:

\[\gamma_{eq}=\gamma_1+\gamma_2+\ldots+\gamma_L\]

where \[\gamma_l=\frac{|h_l|^2\,P_S}{N_{0,l}}\] is the instantaneous SNR of branch l, \[\{h_l\}_{l=1}^L\] defined as independent complex Guanssian Random Variables (RV) with zero-mean, and variance \[\Omega_l/2=E[|h_l|^2]/2\] per dimension, which gives us the case of independent not necessarilly identically distributed Rayleigh fading channels.

Since the branches are independent, then the Moment Generating Function (MGF) of the equivalent SNR equals the multiplication of the (MGF) of all branches. Mathematically:

\[\mathcal{M}_{\gamma_{eq}}(s)=\prod_{l=1}^L \mathcal{M}_{\gamma_l}(s)\]

Then use the MGF-based approach to evaluate the SER or BER for the modulation format use choose.

Regards