A Low Power Interference Robust IR-UWB Transceiver SoC for WBAN Applications - Ultra-Wideband and 60 GHz Communications for Biomedical Applications - page 24

Fig. 1 Application scenario of wireless body area network (WBAN) technology in personal
healthcare
etc. are acquired by individual sensors attached to the human body. The data are
combined at the wireless sensor node and transmitted through the WBAN wireless
link to a portable personal base-station which can be installed in a smart phone. The
data can be further transferred to a remote healthcare center for detailed analysis and
diagnosis by medical professionals. Benefiting from technology advances in biomed-
ical sensor, wireless communication, and integrated circuits, the WBAN technology
helps to develop miniaturized, lightweight, ultra-low power physiological healthcare
surveillance and monitoring devices, for the improvement of human lives [ 3 - 5 ].
Among all kinds of wireless communication systems suitable for WBAN ap-
plications, impulse radio ultra-wideband (IR-UWB) is well known for its unique
low-power and high data-rate merits [ 6 ]. In an IR-UWB system, information is en-
coded in a very narrow pulse of a few nanoseconds, which only occupies a small
fraction of the symbol period. Exploiting the low duty cycle of IR-UWB signal-
ing, the transceiver can achieve low power operation with high energy efficiency.
Noncoherent energy detector (ED) can be employed in the IR-UWB receiver, which
eliminates power consuming local oscillator and carrier synchronization blocks. The
simplified receiver architecture also leads to power reduction and faster turn on time.
Therefore, IR-UWB has been chosen by IEEE 802.15.6 task group as one of the
physical layer solution for high data rate WBAN system [ 7 ].
In a noncoherent ED receiver, the energy of the received signal is measured and
compared to an appropriately selected threshold to determine the presence of a sig-
nal. For an additive white Gaussian noise (AWGN) channel and completely unknown
signal parameters, ED provides the optimal detection performance [ 8 ]. However, the
performance of the conventional ED is sensitive to the narrowband interferences
(NBI). The strong signals from other existing narrow-band wireless communica-
tion systems can saturate the high-gain IR-UWB RF front-end and ED. The major