Why is uwb technology suitable for positioning? Let's understand its application scenarios together

UWB Technology Overview

UWB(Ultra Wideband) is a carrierless communications technology that utilizes narrow pulses of non-sinusoidal waves on the nanosecond to microsecond scale to transmit data. By transmitting very low power signals over a wider frequency spectrum.

The uwb technology is a very advanced technology with a wide variety ofpositioning technologyThe development of people have not been satisfied with the need for external tools to assist the positioning system, we are more inclined to senseless positioning, that is, do not need to swipe the card or face recognition, can be automatically located, which is what we are about to introduce to you uwb technology. Its application scenarios are mainly reflected in the senseless unlocking, indoor high-precision navigation and senseless payment and so on several aspects, want to understand in detail friends hurry to the article to take a look together!

UWB technology began as a pulsed communications technology that emerged in the 1960s and was used primarily in military radar, positioning, and low-intercept/low-detection-rate communications systems.In February 2002, the U.S. Federal Communications Commission issued preliminary regulations for the use of spectrum and power by civilian UWB devices.

In this regulation, communication systems with relative bandwidth greater than 0.2 or greater than 500 MHz at any moment of transmission are called UWB systems, and at the same time, UWB technology was approved to be used for civil commodities. China started the preparation of UWB spectrum planning in 2006. After more than 2 years of research, on December 12, 2008, China's own UWB spectrum planning was formally released, including RF indexes of UWB signals, restrictions on application places, equipment approval and other aspects.

Compared with other positioning technologies, UWB has many advantages such as high positioning accuracy, good security, high transmission rate, large system capacity, low power consumption, and strong anti-interference ability.

Why is uwb technology suitable for positioning?

1. The inherent characteristics of UWB mean that it can achieve more accurate indoor positioning and distance measurements than other technologies. the UWB pulse is only 2 nanoseconds wide and is therefore unaffected by reflected signal interference and noise. the edges of the UWB RF pulse are well defined, so that time of arrival and distance can be accurately determined in the presence of the signal reflections and multipath effects common in everyday environments.

2. When using UWB as a solution, the reflected signal does not affect the direct signal. the rise and fall times of IR-UWB signals are shorter than those of standard narrowband signals, making it possible to accurately measure the signal's arrival time. This also helps the UWB signal maintain its integrity and structure in the presence of noise and multipath effects. Even under noisy conditions, the arrival time of a 2ns wide pulsed radio UWB pulse is virtually unaffected.

3. We have experimented with the ToF-based approach using narrowband radio technology. Narrowband signals are very sensitive to multipath, as reflected signals can combine destructively with direct warp signals to generate a signal at the receiver end. This can affect the time at which the signal exceeds the threshold, which is the time used to measure the ToA, thus reducing accuracy.

Characterization of UWB positioning techniques:

Since UWB works on a very different principle compared to conventional communication systems, UWB has the following technical characteristics that are unmatched by conventional communication systems:

The system architecture is relatively simple to implement:

The communication carriers used in current wireless communication technology are continuous airwaves, where the frequency and power of the carrier varies over a range, thus utilizing the carrier's state changes to transmit information. UWB, on the other hand, does not use a carrier wave and transmits data signals by sending nanosecond pulses.The UWB transmitter directly excites the antenna with pulses in a small way and does not require the up-conversion required by conventional transceivers, thus eliminating the need for utility amplifiers and mixers.

Therefore, UWB allows the use of very inexpensive broadband transmitters. Also at the receiver side, UWB receivers are different from conventional receivers in that they do not require IF processing, thus making the implementation of UWB system architecture relatively simple.

High-speed data transfer:

In civilian goods, UWB signals are generally required to be transmitted within a range of 10m, and then according to the modified channel capacity formula, its transmission rate can be up to 500Mbit/ s, which is an ideal modulation technology for personal communication and wireless LAN.UWB uses a very wide frequency bandwidth for high-speed data transmission, and does not individually occupy the already overcrowded frequency resources, but rather shares the frequency bands used by other wireless technologies. UWB uses a very wide frequency bandwidth in exchange for high-speed data transmission, and instead of occupying a separate, already overcrowded frequency resource, it shares the frequency bands used by other wireless technologies.

In military applications, huge spreading gains can be utilized to achieve long range, low interception rate, low detection rate, high security and high speed data transmission.

Low power consumption:

The UWB system uses intermittent pulses to send data, the pulse duration is very short, generally between 0.20ns~1.5ns, there is a very low duty factor, the system power consumption can be very low, the power consumption of the system in high-speed communication is only a few hundred μW~tens of mW.

Civilian UWB devices are typically about 1/100th the power required by traditional cellular phones and about 1/20th the power required by Bluetooth devices. Military UWB radios also have very low power consumption. Therefore, UWB devices have a great advantage over traditional wireless devices in terms of battery life and electromagnetic radiation.

High security:

As a physical layer technology for communication systems has natural security properties. Since UWB signals generally spread the signal energy over a very wide bandwidth, UWB signals are equivalent to white noise signals for general communication systems, and in most cases, the power spectral density of UWB signals is lower than that of natural electronic noise, and it is very difficult to detect the pulse signals from the electronic noise. Detection of impulses from electronic noise is very difficult. The detection of impulses will be even more difficult after pseudo-randomization of impulse parameters by coding.

High multipath resolution:

Since most of the RF signals in conventional wireless communications are continuous or their duration is much larger than the multipath propagation time, the multipath propagation effect limits the communication quality and data transmission rate. Since ultra-wideband radio transmits single-cycle pulses of very short duration and very low duty cycle, the multipath signals are temporally separable.

If multipath pulses are to overlap in time, the multipath transmission path length should be less than the product of the pulse width and propagation speed. Since the pulse multipath signals do not overlap in time, it is easy to separate the multipath component to fully utilize the energy of the transmitted signal. Numerous experiments have shown that multipath environments with multipath fading as deep as 10-30 dB for conventional radio signals have less than 5 dB at most for ultra-wideband radio signals.

The following figure shows a typical wideband and narrowband multipath post-differential plot.

Positioning is precise:

(b) Impulse pulses have high positioning accuracy, and with ultra-wideband radio communications, it is easy to combine positioning and communications, which is difficult to do with conventional radios. Ultra-wideband radio has a very strong penetration ability, can be indoor and underground for accurate positioning, while the GPS positioning system can only work in the visible range of GPS positioning satellites; with GPS to provide absolute geographic location, unlike the ultra-short pulse locator can give relative position, its positioning accuracy can reach the centimeter level, in addition, the ultra-wideband radio locator is cheaper.

What are the application scenarios for uwb?

According to authoritative research reports, UWB positioning technology applications have maintained a high compound annual growth rate every year. Among them, in industrial manufacturing, chemical industry, power plants, underground construction,Warehouse LogisticsIt has been widely used in the fields of public prosecution and justice, hospitals and so on.

UWB positioning related products: