Biomedical Engineering Reference
In-Depth Information
Fig. 3.5 Propagation
channels implemented in the
simulations
Propagation
channel 3
Router
Propagation
channel 1
Coordinator
Implantable
sensor node
Propagation
channel 2
Wearable
sensor node
Skin
Table 3.1 Simulation
parameters for in body
propagation channel
Parameter
Value
P
0
;
dB
6.3 dB
a
11.6
n
0.5
d
5 mm/80 mm
l
d = 5 mm:2.7, d = 80 mm:8.2
r
d = 5 mm:5, d = 80 mm:6.6
where X
i
represents lognormal shadowing, a
i
p
;
q
are the multipath gain coefficients,
T
p
represents delay of the pth IR-UWB pulse, s
i
p
;
q
is the delay of the qth multipath
relative to pth pulse arrival time and 'i' refers to the ith realization of the channel.
The average path loss (L) of IR-UWB signals at a distance of d for this model is
given by (
3.3
)[
13
]:
;
L2
¼
20 log
ð
d
Þ
and L
¼
L
1
þ
L
2
4pf
c
c
L1
¼
20 log
ð
3
:
3
Þ
where f
c
¼
p
is the geometric centre frequency of the waveform, f
min
and f
max
are the -10 dB edges of the waveform spectrum, c is the speed of light,
L
1
is the path loss at 1 m distance and d is the distance relative to 1 m reference
point. When the simulations are conducted for the scenario where implanted
sensor nodes directly communicate with the coordinator or router node placed
f
min
f
max
