A Full-Body Wireless Wearable UWB-Based Human Motion Capture and Gait Analysis System - E-Healthcare Systems and Wireless Communications - page 445

Figure 1. A simplified diagrammatic representation of on-body inter-segmental measurements using UWB
radios for the initial and during movement measurements (Shaban 2010; Shaban, El-Nasr et al. 2010)
©2010 IEEE. Reprinted, with permission, from Shaban et al., “Toward a Highly Accurate Ambulatory
System for Clinical Gait Analysis via UWB Radios”, in IEEE publication title: IEEE Transactions on
information technology in Biomedicine, vol. 14, NO. 2, Mar. 2010.

width, since in practice multiple pulses are trans-
mitted per bit (Dardari, Chia-Chin et al. 2008).
Generally, the error-performance and power-
consumption tradeoffs have to be carefully studied
in order to choose a suitable receiver structure, and
the corresponding design parameters that guaran-
tee the achievement of a particular system design
target. For this reason, we developed a framework
for the characterization of error-performance and
power-consumption of UWB receivers (Shaban,
El-Nasr et al. 2009).

on the expected values rather than exact values.
For instance, in our link budget calculation we
assume a path loss = 75.6 dB, where based in
our assumed LOS links the path-loss is expected
to be ≈ 10 dB better than the selected value.
Table 1 summarizes the main link budget design
parameters. Typically, our system is expected to
have a 10 dB performance gain compared to this
value, which corresponds to 20 dB link-margin.
The link budget is summarized in Table 1 for an
effective bit-rate = 90 Kb/s, this value is based on
a system range update-rate = 1 Kb/s.

LINK BUDGET Ranging Ziv-Zakai TOA Lower-

Bound on System Performance

In this section, we calculate the link budget for our
system based on actual design parameters. In our
link and power budget calculations, we choose the
maximum expected values and sometimes even
higher values in order to have an upper bound

The n -th order Gaussian pulse p 0 (t) in terms of
σ T p , and the pulse duration T p , has the

form (Sangyoub 2002):

2

= / 2 π