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FM-UWB
FM-UWB is a modulation scheme using double FM: low-modulation index digital FSK followed by high-modulation index analog FM to create a constant envelope UWB signal. FDMA techniques at the subcarrier level may be exploited to accommodate multiple users. The system is intended for low (10–50 kbit/s) and medium (50–250 kbit/s) bit rate, and short-range WPAN systems. The technology, developed at CSEM, is paving the way for true low-power LDR-UWB communication devices. FM-UWB is an optional mode in the IEEE802.15.6 Body Area Network (BAN) standard. See also * UWB Forum * WiMedia Alliance * Wireless Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most ... References * * {{cite web , title=A short range, low data rate, 7.2–7.7 GHz FM-UWB transceiver prototype , website=CSEM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Modulation
Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and Run-length limited#FM: .280.2C1.29 RLL, computing. In Analog signal, analog frequency modulation, such as radio broadcasting, of an audio signal representing voice or music, the instantaneous frequency deviation, i.e. the difference between the frequency of the carrier and its center frequency, has a functional relation to the modulating signal amplitude. Digital data can be encoded and transmitted with a type of frequency modulation known as frequency-shift keying (FSK), in which the instantaneous frequency of the carrier is shifted among a set of frequencies. The frequencies may represent digits, such as '0' and '1'. FSK is widely used in computer modems, such as fax modems, telephone caller ID systems, garage door openers, and other low-frequency transmissions. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra Wideband
Ultra-wideband (UWB, ultra wideband, ultra-wide band and ultraband) is a radio technology that can use a very low energy level for short-range, high-bandwidth communications over a large portion of the radio spectrum. UWB has traditional applications in non-cooperative radar imaging. Most recent applications target sensor data collection, precise locating, and tracking. UWB support started to appear in high-end smartphones 2019. Characteristics Ultra-wideband is a technology for transmitting information across a wide bandwidth (>500 MHz). This allows for the transmission of a large amount of signal energy without interfering with conventional narrowband and carrier wave transmission in the same frequency band. Regulatory limits in many countries allow for this efficient use of radio bandwidth, and enable high-data-rate personal area network (PAN) wireless connectivity, longer-range low-data-rate applications, and the transparent co-existence of radar and imaging systems with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency-shift Keying
Frequency-shift keying (FSK) is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a carrier signal. The technology is used for communication systems such as telemetry, weather balloon radiosondes, caller ID, garage door openers, and low frequency radio transmission in the VLF and ELF bands. The simplest FSK is binary FSK (BFSK). BFSK uses a pair of discrete frequencies to transmit binary (0s and 1s) information. With this scheme, the 1 is called the mark frequency and the 0 is called the space frequency. Modulating and demodulating Reference implementations of FSK modems exist and are documented in detail. The demodulation of a binary FSK signal can be done using the Goertzel algorithm very efficiently, even on low-power microcontrollers. Variations Multiple frequency-shift keying Continuous-phase frequency-shift keying In principle FSK can be implemented by using completely independent free-running oscillat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constant Envelope
Constant envelope is achieved when a sinusoidal waveform reaches equilibrium in a specific system. This happens when negative feedback in a control system, such as in radio automatic gain control or when an amplifier reaches steady state. Steady state, as defined in electrical engineering, occurs after a system becomes settled. To be more specific, control systems are unstable until they reach a steady state. Constant envelope needs to occur for the system to be stable, where there is the least amount of noise and feedback gain has rendered the system steady. Feedback is used to create a feedback signal to control gain, reduce distortion, control output voltage, improve stability or create instability, as in an oscillator. Some examples of constant envelope modulations are as FSK, GFSK, MSK, GMSK and Feher's IJF - All constant envelope modulations allow power amplifiers to operate at or near saturation levels. Although, the power spectrum efficiency of a non-constant amplit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FDMA
Frequency-division multiple access (FDMA) is a channel access method used in some multiple-access protocols. FDMA allows multiple users to send data through a single communication channel, such as a coaxial cable or microwave beam, by dividing the bandwidth of the channel into separate non-overlapping frequency sub-channels and allocating each sub-channel to a separate user. Users can send data through a subchannel by modulating it on a carrier wave at the subchannel's frequency. It is used in satellite communication systems and telephone trunklines. FDMA splits the total bandwidth into multiple channels. Each ground station on the earth is allocated a particular frequency group (or a range of frequencies). Within each group, the ground station can allocate different frequencies to individual channels, which are used by different stations connected to that ground station. Before the transmission begins, the transmitting ground station looks for an empty channel within the freq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kbit/s
In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multiples of bits per second (bit/s) and bytes per second (B/s). For example, the data rates of modern residential high-speed Internet connections are commonly expressed in megabits per second (Mbit/s). Standards for unit symbols and prefixes Unit symbol The ISQ symbols for the bit and byte are ''bit'' and ''B'', respectively. In the context of data-rate units, one byte consists of 8 bits, and is synonymous with the unit octet. The abbreviation bps is often used to mean bit/s, so that when a ''1 Mbps'' connection is advertised, it usually means that the maximum achievable bandwidth is 1 Mbit/s (one million bits per second), which is 0.125 MB/s (megabyte per second), or about 0.1192 MiB/s (mebibyte per second). The Institu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swiss Center For Electronics And Microtechnology
The CSEM is a Swiss research and development centre (R&D) active in the fields of precision manufacturing, digitalization, and renewable energy. It follows a public-private not-for-profit partnership model. CSEM develops and transfers technologies that are considered relevant in progressing the Swiss national economy. CSEM is a R&D Center of Science and technology in Switzerland. Organization CSEM’s mission is to develop and transfer technologies to the industrial sector to reinforce the sector’s competitive advantage. It works towards building ties between higher education institutions and partners in Industry, and aims to help entrepreneurs with the creation of start-up companies. CSEM’s headquarters are located in Neuchâtel, Switzerland. It also has three regional research and development centers in the Swiss cities of: Muttenz, Alpnach and Landquart, and an office at the Technopark Zürich. History CSEM was founded in 1984 by The Swiss Federal Council. It w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UWB Forum
The UWB Forum was an industry organization promoting interoperable ultra-wideband (UWB) wireless computer networking products from multiple vendors. It was founded in 2004 and disbanded around 2006. History The UWB Forum was founded in 2004, promoting acronyms such as DS-UWB and CSM. Within the Institute of Electrical and Electronics Engineers, the IEEE_802.15.3a effort attempted to provide a higher speed ultra-wideband enhancement amendment to IEEE 802.15.3 for applications which involved imaging and multimedia. That standardisation attempt failed due to contrasting approaches between the WiMedia Alliance and UWB Forum. On January 19, 2006 IEEE 802.15.3a task group (TG3a) members voted to withdraw the December 2002 project authorization request (PAR) that initiated the development of high data rate wireless standards. The IEEE 802.15.3a did consolidate 23 physical layer specifications into two proposals: multi-band orthogonal frequency-division multiplexing (MB-OFDM), supported ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WiMedia Alliance
The WiMedia Alliance was a non-profit industry trade group that promoted the adoption, regulation, standardization and multi-vendor interoperability of ultra-wideband (UWB) technologies. It existed from about 2002 through 2009. History The Wireless Multimedia Alliance was founded by 2002. The WiMedia Alliance developed reference technical specifications including: * Physical layers and media access control (MAC) layers * Convergence architecture to provide coexistence and fairness including support for multiple applications * A protocol adaptation layer for the Internet Protocol * IP-based application profiles The WiMedia ultra-wideband (UWB) common radio platform incorporated MAC layer and PHY layer specifications based on multi-band orthogonal frequency-division multiplexing (MB-OFDM). It was intended for short-range multimedia file transfers at data rates of 480 Mbit/s and beyond with low power consumption, and operates in the 3.1 to 10.6 GHz UWB spectrum. WiMedia UWB was p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wireless
Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most common wireless technologies use radio waves. With radio waves, intended distances can be short, such as a few meters for Bluetooth or as far as millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of applications of radio ''wireless technology'' include GPS units, garage door openers, wireless computer mouse, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones. Somewhat less common methods of achieving wireless communications involve other electromagnetic phenomena, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
