large channel capacity of UBW signals on the signal-to-noise ratio (SNR) allows them to thrive in noisy environments. Carrier-free signal The capability of UWB technology to directly modulate data in the form of pulses during transmission significantly minimises hardware requirements for incorporating this technology into smart home systems. Moreover, this capability results in lower implementation costs given that UWB does not require advanced equipment such as equalisers, frequency mixers, shaping filters, and digital to analogue converters.
of adequate solutions for overall energy management in smart homes, depending on customer requirements. Other smart home applications will be explored later in this article. Table 1 compares some existing wireless connection standards, alongside UWB. The table shows that UWB offers the lowest energy per bit and the highest maximum bit rate. Moreover, UWB is widely associated with high data rates, low power consumption, and wide bandwidth. Other key characteristics of the ultra- wideband technology include large channel capacity, carrier-free signalling, innovative modulation techniques, and resistance to multipath fading and jamming [3] .
to create pulses and minimise interference in UWB signals. While PPM shifts the pulses in the time domain to result in small time duration pulses (approximately 1ns), CDMA and OFDMA prevent the possible interception of signals by nearby users and eliminate signal interference, respectively. Resistance to multipath fading and jamming The wide bandwidth of a UWB signal makes it resistant to multipath fading, which is a common occurrence in narrowband signals. Moreover, unlike narrowband signals that jamming devices can easily block, these devices cannot completely block UWB signals. Benefits of UWB UWB is beneficial in smart home applications for access control, real-time location systems (RTLS), device tracking, indoor navigation, point-and-trigger control, etc [4] . UWB can track the exact locations of smart home users when they enter or exit their homes, allowing them instant and hands-free access after verifying their security credentials. This wireless tracking capability of the technology makes it ideal for access control in smart home systems. Incorporating UWB technology into smart home systems allows
Technical specifications of UWB
Standard Energy per bit (nJ/bit)
Maximum bit rate (Mb/s)
Maximum range (m)
ZigBee
296
0.25
75
Bluetooth 34
1
15
Wi-Fi UWB
130
54
100
5
100
10
Table 1: Comparison of Various Wireless Standards. Credit: Khajenasiri et al. (2015)
Large channel capacity The US Federal Communications Commission (FCC) describes any signal with a bandwidth of over 500MHz as an ultra-wideband signal. The independence of the
Modulation techniques
UWB uses Pulse Position Modulation (PPM), Code-Division Multiple Access (CDMA), and Orthogonal Frequency Division Multiplexing (OFDM) techniques
we get technical
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