170 Chapter
7
Figure 7-35. Block diagram of a simple channel model
The main characteristics of the simple channel model are as follows.
Additive white Gaussian noise (AWGN) with power level pn_dBm,
which is specified by the input signal power ps_dBm and the signal-to-
noise ratio s_to_n
_
30
10
0
10
pn dBm
vn
Z , where pn_dBm
ps_dBm s_to_n
1
1
2
2 log(
) cos(2
)
noise
v
vn
x
x , where x1, x2 are uniformly
distributed random numbers (
1,2
1
0
1,
0
x
x
)
For the input signal a delay td can be specified.
Input and output impedances are modeled as ohmic resistances with
default values
0
50
in
out
Z
R
R
Additional characteristics, that were not modeled here, include multi-path
propagation of the signal due to reflection with different delays and damping
factors for different paths, frequency response, nonlinear distortion, etc.
Thus far the model is very general and suited to RF applications as well as to
wired data transmission, where effects like crosstalk and reflection due to
mismatch are predominant.
Summary :
Additive white Gaussian noise (AWGN) with power level pn_dBm, which is specified by the input signal power ps_dBm and the signal-to- noise ratio s_to_n _ 30 10 0 10 pn dBm vn Z , where pn_dBm ps_dBm s_to_n 1 1 2 2 log( ) cos(2 ) noise v vn x x , where x1, x2 are uniformly distributed random numbers ( 1,2 1 0 1, 0 x x ) For the input signal a delay td can be specified.
Tags :
input,noise,model,signal,power,modeled,characteristics,due,pndbm,reflection,simple,channel,ston