Ultra-wideband (UWB) is a wireless technology specifically for short-range personal area networks (PANs) , and is also a leading technology that is carefully crafted to enable next-generation wireless interconnection of computer peripherals, home appliances, and other mobile devices. With high available bandwidth, UWB will support wireless connections between multiple devices, as well as the transmission of video, audio and other data streams. For example, UWB can transfer the video content of computers or household appliances ( such as video cameras, DVD players or personal video recorders ) to a flat HDTV display without using any cables.
Picture 1 Â Multi-band OFDM band plan
Â
Picture 2 Â Â Universal UWB wireless platform view
How UWB works
UWB transmitters work by sending billions of pulses over a wide gigahertz bandwidth through a few gigahertz bandwidth. The corresponding receiver then converts these pulses into data based on the frequency of similar pulses sent by the transmitter. Specifically, UWB refers to a wireless technology whose spectrum occupies more than 20% of the center frequency or at least 500 MHz of bandwidth.
UWB transmission technology uses pulses to modulate information in a wide spectrum. The pulse width in the time domain determines the occupied bandwidth in the frequency domain.
Problems faced by UWB
UWB faces many challenges in the approval of global regulatory agencies. The United States is currently the only country that allows UWB commercial applications. In different countries and regions around the world, the allocation of UWB spectrum varies greatly. For example, the Japanese government encourages wireless system developers to avoid using multiple narrowbands within the UWB spectrum allocated to radio observatories . Other countries have stipulated similar UWB wireless usage rules.
The advantage of UWB is that it can dynamically turn off subbands and individual audio to comply with the local operating specifications on the specified spectrum, thereby meeting regional management policies. With UWB's flexible spectrum modulation capabilities, once UWB products are put on the market, wireless technology is expected to be legally approved by many countries. Many countries in the Asia-Pacific region have plans to allocate UWB spectrum from the second half of 2004 or 2005. Japan and South Korea will take the lead in following the pace of the FCC . European countries are also expected to allocate this spectrum in the next few years.
Multiband OFDM Alliance (MBOA)
Researchers are currently seeking multi-band orthogonal frequency division multiplexing (OFDM) close to UWB to gain many advantages. This means that the multi-band OFDM method can achieve perfect coexistence with narrow-band systems ( such as 802.11a) , adapt to different regulatory environments, and support future expansion and backward compatibility. With the establishment of the Multi-Band OFDM Alliance (MBOA) , OFDM modulation for each sub-band was added to the original multi-band method in order to develop the best technical solution for UWB .
MBOA in June 2003, co-founded by the most influential consumer electronics, personal computers, home entertainment, digital imaging and semiconductor manufacturers, whose purpose is for the emerging UWB (IEEE 802.15.3a) PHY specification to develop the best technological solutions Programs to support a wide range of applications. To date, the Multiband OFDM Alliance has more than 50 members and supports a single UWB technical solution.
Multi-band OFDM method
In the multi-band OFDM method, the available 7.5 GHz spectrum is divided into multiple 528 MHz bands. This allows selective implementation of frequency bands within a specific frequency range, while leaving the rest of the spectrum idle. The dynamic capability of radio frequency operation in a specific range of the spectrum is very important, and it can well adapt to the regulatory requirements of governments around the world.
The frequency band plan of the MBOA scheme divides the frequency band into four groups of AD , as shown in Figure 1 . Wherein group B (4.9GHz - 6.0 GHz) and group D (8.1GHz -10.6GHz) for later use.
Multiple sets of frequency bands can realize multiple operating modes of multi-band OFDM devices. According to the current multi-band OFDM scheme, Band 1 to Band 3 are used for Mode 1 devices ( required mode ) ; Band 6 to Band 9 are used for Mode 2 ( optional mode ) .
The information transmitted on each frequency band is modulated by OFDM . OFDM distributes data on a large number of carriers divided by precise frequencies. These spaces can provide the technology with "quadrature" capabilities, which can prevent the demodulator from seeing frequencies other than itself.
Multiple advantages of OFDM
The advantages of OFDM include: high spectral efficiency, strong resistance to radio frequency interference, and low multipath distortion rate. By using OFDM modulation technology and multi-band technology, it is easier to use a single RF chain to collect multi-path energy, so that the receiver can resist narrow-band interference without losing sub-band resources or reducing the data rate. These advantages will help turn off individual audio, and use forward error correction coding to more easily recover damaged audio.
Although this will increase the complexity of the wireless design, it is important to point out that the key signal processing block in OFDM (FFT / IFFT) indicates that 50k gates are required , which only accounts for a small part of the total chip area. In addition, this function can be integrated into deep sub-micron CMOS processes to extend Moore's Law to achieve most of the receive path functions.
The total silicon die area of ​​the PHY solution is expected to be 4.9 square millimeters for Mode 1 (3- band ) devices , and 3.0 square millimeters and 1.9 square millimeters for the analog / RF part 1 and digital part, respectively . These are expected to use 90- nanometer CMOS technology nodes in 2004 , and the digital part of the PHY is expected to require 295K gates. In essence, the manufacture of multi-band OFDM UWB wireless technology itself will become increasingly simple, and will take full advantage of the advantages brought by Moore's Law.
UWB application
The concept of UWB wireless has penetrated into many different applications and industries, and has become a recognized "universal UWB wireless platform". Together with the fusion layer, UWB wireless has become the basic transmission mechanism for different applications, some of which currently only support wired connections. Some of the more important applications running on the universal UWB platform include Universal Serial Bus (USB) , IEEE 1394 , next-generation Bluetooth, and Universal Plug and Play (UpnP)-see Figure 2 .
This concept has brought many potential applications and created the first high-speed wireless interconnection. This article is not intended to provide a comprehensive introduction to all possible usage models, but to analyze the core capabilities of the technology in depth.
For wireless computer peripheral connections, UWB technology provides comprehensive performance and ease of use unmatched by other interconnect options today. At present, wired USB occupies a large share in the computer platform cable interconnection market. However, users have put forward higher requirements on the convenience and ease of use of cables. By getting rid of the cable between the peripherals and the computer, and providing the wired USB connection performance that users expect , UWB has become increasingly important in the computer peripherals interconnect market. A typical application of UWB is to wirelessly connect mobile devices ( such as portable media players (PMP)) and content resources ( such as personal computers, laptops, or external hard disks (HDD)) . Once authenticated and authorized, the device and personal computer can batch transfer video files to PMP for later enjoyment.
Closely related to computer connection is the wireless multimedia connection of home audio-visual equipment. The ease of use of wireless connections and data transmission performance in such devices are key factors. For example, wireless connectivity is an ideal choice for wall-mounted plasma displays, because users do not want to see the connection cable to the STB for aesthetic reasons . Another mode of use is the ability to load DVDs and wirelessly transmit video content to digital televisions (DTV) . The characteristic of this usage mode is the ability to transmit data stream content to multiple devices at the same time. This will support the picture-in-picture function, or browse the same or different content on multiple visual devices.
Fusion equipment requirements
The home appliance category also requires key fusion equipment for use in computer environments and entertainment center clusters. Portable home audio and video equipment, such as DV camcorders, digital cameras, portable MP3 audio players, and emerging personal video players, will all become backup forces for the early UWB mainstream market. The reason is that the market's unique needs for these devices, and UWB can meet these needs.
Fusion equipment requirements
The home appliance category also requires key fusion equipment for use in computer environments and entertainment center clusters. Portable home audio and video equipment, such as DV camcorders, digital cameras, portable MP3 audio players, and emerging personal video players, will all become backup forces for the early UWB mainstream market. The reason is that the market's unique needs for these devices, and UWB can meet these needs. Â
These requirements include high-speed data transmission of multimedia content, short-range transmission to other devices, low power consumption due to limited battery capacity, low complexity and low-cost requirements due to market price pressure, and alternative options for wired connections. The expected usage mode is to transfer the video content in the digital camera to other display devices ( such as DTV) for playback. Another example is to enjoy photos from a user's digital camera (DSC) on a large display .
Conclusion
UWB is a very promising wireless interconnection technology for computer peripherals, home appliances and other mobile devices. Researchers and engineers are working to deploy UWB technology in the near future . With the standardization of the universal UWB development platform, manufacturers in the computer, mobile device and home appliance markets will be able to choose UWB as the physical layer to take full advantage of the low energy consumption and high bandwidth advantages brought by the technology.
Hengstar designs and develops various industrial LCD displays for industrial control systems. There are multiple installation methods including: desktop installation, universal VESA mount, panel mount, flush mount and rack mount, making our monitors suitable for different types of industrial control and factory automation.
Industrial Monitors,Industrial Touch Monitor,Industrial Lcd Monitor,Industrial Touch Screen Monitor
Shenzhen Hengstar Technology Co., Ltd. , https://www.angeltondal.com