Radar Sensing Using Ultra Wideband – Design and Implementation

Ultra-WideBand (UWB) communication systems are usually classified as any communication system whose instantaneous bandwidth is many times greater than the minimum bandwidth required to deliver information. UWB communication is fundamentally different from all other communication techniques because it employs extremely narrow Radio Frequency (RF) pulses to communicate between transmitters and receivers. Utilizing short-duration pulses as the building blocks for communications directly generates a very wide bandwidth and offers several advantages, such as large throughput, covertness, robustness to jamming, and coexistence with current radio services. UWB technology offers a promising solution to the RF spectrum drought by allowing new services to coexist with current radio systems with minimal or no interference. This coexistence brings the advantage of avoiding the expensive spectrum licensing fees that providers of all other radio services must pay. In this chapter, the application of UWB technology in military areas has been summarized. Its wider applications has been evaluated over several leading technology including military technology systems, government sectors, communication systems, surveillance systems, rescuing, logistics entertainment, public transport, and others.

1.1 Impulse Radio (IR) Ultra Wideband (UWB) Communications Ultra wideband (UWB) communication is a fast emerging technology that offers new opportunities such as high data rates, low equipment cost, low power, precise positioning capability and extremely low interference Ghawami (2005). A wide range of possible UWB communication system applications includes radars due to UWB ultra high precision ranging at the centimeter level, wireless personal area networks (WPAN), sensor networks, imaging systems, UWB positioning systems, etc. Yang (2004), Kshetrimayum (2009). From a commercial point of view, the high data rates are the most attractive feature of UWB systems for which speeds of over 100Mb/s have been demonstrated Ghawami (2005). There exist three main types of UWB technologies: impulse radio (IR UWB), direct sequence (DS UWB), and multi-band orthogonal frequency division multiplexing (MB OFDM) Ran (2009). IR UWB communication technique is essentially different from all other communication techniques because it is carrier free and uses for communication between transmitters and receivers very narrow radio frequency (RF) pulses generated from the UWB pulse generator, while traditional transmission systems transmit information by varying the power, frequency, and/or phase of a sinusoidal wave in a modulation process Kshetrimayum (2009), Yao (2007). Consequently, complicated frequency mixers and local oscillators for carrier frequency up and down conversion are not necessary Yao (2007). IR UWB modulation techniques are especially important because the UWB spectrum has been made available by the Federal Communication Commission (FCC) and it can be used with IRs developed to date Lin (2005). Waveforms for IR UWB are designed to obtain a flat frequency response over the bandwidth of the pulse and to avoid a DC component. The large spectrum of a UWB signal may interfere with existing users. In order to keep this interference to the minimum, FCC specifies spectral masks for different applications, i.e. the allowed power output for specific frequencies Ghawami (2005). A contiguous bandwidth of 7.5GHz is available in the frequency interval of (3.1− 10.6)GHz at a maximum power output of −41.3dBm/MHz which is considered as extremely low Ghawami (2005). The power spectral density (PSD) of UWB systems defined as a ratio of the transmitted power P in watts and a signal bandwidth B in hertz is extremely low as compared to other communication systems due to the very wide bandwidth B of short pulses that are typically of nanosecond or picosecond order Ghawami (2005). The selection of the impulse signal type for IR UWB communication system is essential since it determines

This paper presents a wireless video streaming system over Ultra Wide Band (UWB) radio. Wireless video steaming is not a possibility so far due to its high bandwidth requirements and high power consumption. With Ultra Wide Band (UWB), a low power, high speed radio technology standard developed by the WiMedia Alliance; the dream of wireless video streaming become true. By giving the fact of UWB, 480 Mbps with transmission mask of -41 dbm/MHz; the UWB supports uncompressed or lossless compressed video screen size up to SVGA (800x600x24) with 30 frames/second rate. This is an extraordinary achievement concerning wireless video application. This paper will introduce a demonstration system that uses a Nokia 7710 phone as a UWB transmitter and a projector as a UWB receiver. The demonstration is a result of collaboration between Nokia Research Center Helsinki and WiQuest Communications Inc. USA.

Power efficient ultra-wideband based wireless communication for wireless body area network applications

The emerging feature-rich and high-data-rate wireless applications have put increasing demand on radio spectrum. The scarcity of spectrum and the inefficiency in its usage, as caused by the current radio spectrum regulations, necessitate the development of new dynamic spectrum allocation policies to better exploit the existing spectrum. The current spectrum allocation regulations assign specific bands to particular services, and grant licensed band access to licensed users only. Cognitive Radio (CR) will revolutionize the way spectrum is allocated. In a CR network, the intelligent radio part allows unlicensed users (secondary users) to access spectrum bands licensed to primary users, while avoiding interference with them. In this scheme, a secondary user can use spectrum sensing hardware/software to locate spectrum portions with reduced primary user activity or idle spectrum slots, select the best available channel, coordinate access to this channel with other secondary users, and vacate the channel when a primary user needs it. To achieve this, the transceiver in a CR system should have awareness of the radio environment in terms of spectrum usage, power spectral density of transmitted/received signals, and wireless protocol signaling, should be able to adaptively tune system parameters such as transmit power, carrier frequency, and modulation strategy. The transceiver should also be ended with an antenna system that can simultaneously operate over a wide frequency band (sensing) and a chosen narrow band (communication), or operate over an ultra-wide frequency band while possibly blocking signals in a narrow frequency range. Ultra-wideband (UWB) is a transmission technique that uses pulses with a very short time duration across a very large frequency portion of the spectrum. UWB is different from other radio frequency communication techniques in that it does not use RF carriers, but instead employs modulated high frequency pulses of low power with a duration of less than 1 nanosecond. From the perspective of other communication systems, the UWB transmissions are part of the low power background noise. Therefore UWB promises to enable the usage of licensed spectrum without harmful interference to primary communication systems, and can be used as an enabling technology for implementing CR. In this chapter, we offer a general overview of Cognitive Radio and dynamic spectrum access, discuss the advantages of using UWB as an enabling technology for CR, and give

An indoor positioning system (IPS) is a technology employed to locate objects and people within a building scenario using signal processing or other sensory information. Ultra Wide Band (UWB) is a versatile wireless technology that can be employed as an IPS and has shown very good performances. UWB can be used in many scenarios and its effectiveness in through wall detection along with its excellent resolution for person localization is one of the best applications of Impulse Radio (IR) UWB. The main objective of this work is to propose a concept for intelligent radar systems employing UWB augmented by machine learning approaches to not only localize but understand the location of a person or target within a building. Although suitably developed UWB is excellent for obtaining localizing data it does not automatically understand what that location effectively means or where it is thus further methods are required to create meaningful data for end user appreciation. Learning from the huge amount of UWB signal data through Multi Class Support Vector Machine (MC-SVM) architecture enables a truly evolving scheme to both localize targets and identify them in a useful way. Statistical analysis of the experimental results supports the proposed algorithm.

This letter presents an application of multiobjective topology optimization to ultrawideband (UWB) antenna design. The design of UWB antennas is very challenging because it involves multiple design goals including miniaturization, a wide impedance bandwidth, uniform gain variation, and enhanced time-domain pulse preservation. Although topology optimization has been a popular approach for UWB antenna design, a multiobjective version that systematically copes with all the design details is critically lacking, and the early attempts have not been very successful. In this letter, we propose a Pareto-based technique for multiobjective topology optimization, showing that the proposed methodology facilitates the development of a UWB antenna with compact size, a wide bandwidth, uniform gain variation, and high fidelity factors. The optimized UWB antenna occupies a small area of $15 \times 15~\hbox{mm}^2$ , showing excellent impedance matching and stable broadside gains throughout 3.1–10.6 GHz. In addition, the variation of group delay drops dramatically from 0.94 to 0.40 ns, and the fidelity factor is enhanced from around 0.80 to 0.92. The simulated and measured results are exhibited, confirming the validity of multiobjective topology optimization.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation S. Sesha Vidhya, K. G. Shanthi, P. Sivalakshmi, V. Sohith Reddy, V. Likith Varma, V. Dileep Kumar, Y. Prasanth Reddy; Design of UWB wearable microstrip patch antenna for wireless body worn applications. AIP Conference Proceedings 30 January 2023; 2523 (1): 020158. https://doi.org/10.1063/5.0111136 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM) is an efficient approach for Ultra Wideband (UWB) wireless communication applications. However, the high Peak to Average Power Ratio (PAPR) of MB-OFDM UWB signals, limits the power efficiency of the Solid State Power Amplifier (SSPA) due to nonlinear distortion caused by high PAPR. Hence, it is necessary to reduce the PAPR of MB-OFDM UWB signals. In this paper, we used a tunable Pre-Distorter (PD) based on the High Power Amplifier (HPA) characteristics for PAPR reduction of MB-OFDM UWB signals. The PD configuration is self-tuning, i.e., it can automatically readjust itself by tracking changes in the HPA characteristics with very few (typically two) training symbols. Through Computer simulations, the performance of the predistorter is evaluated in comparison with filtering after clipping, and clipping with turbo coding for PAPR reduction. The Bit-Error Rate (BER) is used as performance measure in this evaluation.

Ultra-wide band (UWB) ground wave (GW) is a novel means of communications for use with distributed networked sensors at sea. Although multiple distributed sensor systems are in development, the communications method for these systems has yet to be fully realized. The buoys that relay the sensor information have several key features: they must be small enough so they are not highly noticeable and do not pose a navigation hazard; they must be cheap enough to be expendable; they must be able to run on limited battery power; the communications link must be at a great enough distance so that fewer buoys are needed; and they must deal with multipath from the sea surface. Ultra-wide band ground wave will address many of these issues. UWB is being developed commercially at 3-10 GHz. UWB requires low power and the transmitters are extremely easy to implement making the system inexpensive and small. UWB provides low probability of detection and interception. However commercial UWB operates at very short distances. Implementing UWB Ground Wave instead of commercial-band UWB will extend the communication range between buoys up to 10 miles. The distributed sensors will transmit to a central buoy for data relay via satellite or communicate directly to a submarine, UUV or surface ship antenna. This project is currently being funded by Office of Naval Research (ONR) 313. The project commenced in October 2005.

This paper presents a brief review and recent development of ultra-wideband (UWB) filters for microwave UWB radio system (from 3.1 to 10.6 GHz) using broadside-coupled structures. Design considerations and requirements for such UWB filters to meet the UWB regulation are described. Several recently developed UWB filters, including full FCC UWB bandpass filter, UWB lowpass filter, notch-band implemented UWB bandpass filter for avoiding interference, and a super UWB filter with wider bandwidth than conventional UWB system are demonstrated.

Ultra-wideband (UWB) is an alternative wireless communications technology that offers high bandwidth wireless communications without the constraints of spectrum allocation. Fundamentally different from conventional radio frequency communications, UWB relies on a series of narrow, precisely timed pulses to transmit digital data. Transmitters and receivers that use UWB can be much simpler to build than their conventional counterparts, resulting in lower cost and higher power efficiency. Moreover, the inherent properties of UWB emissions allow them to potentially coexist with conventional wireless systems on a noninterfering basis. In April 2002, the Federal Communications Commission (FCC) released UWB emission masks and introduced the concept of coexistence with traditional and protected radio services in the frequency spectrum, which allows the operation of UWB systems mainly in the 3.1 to 10.6 GHz band, limiting the power level emission to -41dBm/MHz. Within the power limit allowed under the current FCC regulations, Ultra-wideband can not only carry huge amounts of data over a shortto- medium distance at very low power (this range can be extended by using ad-hoc or mesh networks), but it also has the ability to carry signals through doors and other obstacles that tend to reflect signals at more limited bandwidths and a higher power (Reed, 2005). At higher power levels, UWB signals can travel to significantly greater ranges. In March 2005, the FCC granted the waiver request, filed by the multiband Orthogonal Frequency Division Multiplexing (OFDM) alliance (MBOA), in which it approved the change in measurement for the all UWB technologies (neutral approach) (Barret, 2005). The FCC’s waiver grants effectively removes the previous transmit power penalties for both frequency-hopping (OFDM) and gated UWB technologies (TH and DS). Hence, they are allowed to transmit at higher power levels and then become idle for some time, as long as they meet the limits for average power density. This new rules allow those technologies to achieve up to four times better performance and double the range.

The inter-vehicles communication is becoming increasingly mandatory to improve the road safety and to allow a better transport management. The concept behind an intelligent vehicle consists in equipping this vehicle with an optimum number of sensors, in order to perceive the environment surrounding it and to ensure an automatic guidance control and the communication with the infrastructure and other vehicles. Among the most often used tools for this objective, we can cite the embedded radar. Moreover, the Ultra Wide Band (UWB) communication systems are under fast development and undergo progressive implementation. The principle of UWB technology is to transmit rather low power, carrier-less, signals occupying a very broad spectrum [1]. The spectral concentration of radiated power is thus extremely low, so that the other systems perceive UWB ones like background noise. In this article, a road radar based on UWB technology is studied. The proposed device allows, in a road environment, good resolution and increased precision for detection and localization of obstacles.

One of the main advantages of ultra wide band (UWB) systems is the extreme time resolution due to the huge bandwidth of several GHz. This allows the distinction between many different propagation paths in multipath environments and thus transmits with very low power. In order to benefit from the advantages of UWB, accurate estimations of the current channel realization are necessary. We derive theoretical boundaries for pulse transmission for the expected BER, the accuracy of the channel estimation and the interaction between these two problems. As an example, the popular time-hopping pulse-position-modulation UWB (TH-PPM UWB) is used to show the trade-off between information and channel estimation.

Today's medical implants communicate with each other over radio, typically using standards such as MICS. However, in order to reduce power consumption and improve datarates, we need to explore better standards. Ultra wide band radios (UWB) are known to be low power. While studies on UWB radios for on-body implants exists, no study exists which explains the effect of UWB for in-body medical implants. This paper shows that Ultra wideband (UWB) can be a feasible solution for in-body medical implants in certain cases. We present a model to compute path loss inside human body tissues, for frequencies in the UWB standard, a study that has not been done so far. Furthermore, we extend this model to include reflection losses. We will show from our study that UWB is an excellent option for short-distance inter-implant communication and combined in- and on-body communications.