A virtual prototype for Bluetooth over ultra wide band system level design

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

A novel method to generate ultra-wideband (UWB) signals based on two differential group delay modules and one Mach-Zehnder Modulator is proposed. Both simulation and experiments verified that the method could generate two kinds of UWB monocycles using low bit-rate non-return-to-zero data source (1Gbps). The monocycles have a fractional bandwidth of 127% at centre frequency 5.5GHz. Keywords: Ultra wideband (UWB), radio-over-fiber (RoF), differential group delay (DGD) 1. INTRODUCTION Ultra-wideband (UWB) is a fast emerging technology for short-range broadband wireless communication such as wireless personal area network and sensor network, etc. The UWB signal occupies wide bandwidth and has low power density, and it has immunity to multi-path fading [1]. As a carrier-free modulation scheme, direct-sequence impulse radio is more cost-effective and simpler compared with multi-band orthogonal frequency scheme. Since UWB is a room-scaled short range wireless communication technique, the wireless networks can operate mainly in indoor environment in standa lone mode. Considering the integration of UWB access networks and fixed wired networks, the combination of UWB-over-fiber technology and fiber-to-the-home (FTTH) technology is a competitive candidate for future wideband access networks [2]. So many all-optical schemes that fit for UWB-over-fiber technology to generate and distribute UWB impulses have been reported recently. Zeng et al. proposed two approaches to generate UWB impulses using one phase modulator (PM), and 25-km single mode fiber (SMF) or FBG to convert phase-modulated light to UWB pulses [3, 4]. Wang and Dong proposed UWB signal generation using cross-gain modulation or cross-phase modulation in semiconductor optical amplifier [5, 6], which requires two laser sources and may increase the system complexity. Chen proposed a scheme based on optical polarization time delay [7]. It is a simple method, but the elect rical signal source needs at least twice bit-rate compared to the carried data. Most of the schemes n eed an electrical Gaussian pulse source, which is comm only composed of a high-speed pulse pattern generator (PPG). This is an expensive construction, for which the PPG should work at least 10 Gbps. Furthermore, if data are carried on the UWB pulses, another modulator should be added to the systems, which increase the system cost and complexity. In this paper, we proposed and experimentally demonstrated a simple method to generate data-carried UWB monocycle pulses based on two differential group delay (DGD) modules and one Mach-Zehnder modulator (MZM). Instead of the data pattern “1000 0000 ”, which has one “1” followed by several “0”s to form the UWB signal, we use electrical non-return-to-zero (NRZ) data. The NRZ data modulate the optical signal in MZM to get an optical binary phase shift keying (BPSK) signal, which is then fed into two cascade DGD module s while the polarization of the light is carefully adjusted

Ultra-wideband (UWB) communications has emerged as a promising technology for high data rate wireless personal area networks (WPANs). In this paper, we address a key issue that impacts the performance of multi-hop, multi-rate UWB-based WPANs, namely joint routing and rate selection. Arbitrary selection of routes (including direct links) and transmission rates along these routes results in unnecessarily long channel reservation time and high blocking rate for prospective reservations, and leads to low network throughput. To remedy this situation, we propose a novel overhearing-aware joint routing and rate selection (ORRS) scheme, which improves the network throughput by exploiting the dependence between the channel reservation time and the multi-rate capability of an UWB system. At the same time, ORRS takes advantage of packet overhearing, a typical characteristic of broadcast communications. For a given source-destination pair, ORRS aims at selecting a path and its transmission rates that achieve the minimum reservation time, leading to low blocking rate for prospective reservations and high network throughput. We show that achieving this goal while simultaneously exploiting packet overhearing and satisfying a target packet delivery probability over the selected route leads to an NP-hard problem. Accordingly, ORRS resorts to approximate solutions (proactive and reactive) to find a near-optimal result with reasonable computational/communication overhead. We further propose other variants that exploit packet overhearing in different ways to improve ORRS performance.

A frequency domain multiple-antenna and channel estimation approach for facilitation of UWB technologies coexistence in heterogeneous WPANs

Ultra-wideband (UWB) communication is a promising technology to provide high data rates with low power consumption in wireless personal area networks. Among the standards adopting the UWB technology, Wireless USB (WUSB) running on the platform of WiMedia aims to provide high-speed wireless connectivity between mobile devices. To support reliable connectivity, data rates should be adapted according to UWB channel states that are time- varying. In this paper, we propose a novel rate adaptation scheme which considers the characteristics of WUSB protocol as well as the time-varying UWB channel. Our proposed scheme uses the channel prediction in a short time scale. Specifically, the channel state of the previous time window is used to determine the data rate of the next time window, assuming the channel similarity between the two successive time windows. Through extensive trace-driven simulations, we show that the proposed rate adaptation scheme outperforms the conventional schemes.

Summary form only given. Convergence of communication and computing technologies is rapidly changing the requirement of wireless devices. While wireless wide area network (WWAN) based on cellular radios was evolving, a new set of wireless LAN networks which are fundamentally different from cellular networks emerged. Devices for applications in the wireless LAN networks (WLAN), wireless personal area networks (WPAN) and wireless metro area networks (WMAN) are being deployed in increasing numbers. Bluetooth and Ultra Wideband (UWB) technologies have been introduced for high-bandwidth wireless connectivity in personal area networks. Location identification technologies like GPS are getting integrated with wireless products as well. There is no doubt that tomorrowpsilas network environment will be extremely heterogeneous.

Ultra-Wideband (UWB) transmission is a promising technology for high speed wireless networks such as wireless personal area networks (WPANs). The detection of UWB signals is a key issue for system performance and capacity. In this paper, we propose a novel signal detection technique for multiple access UWB systems. Our approach is based on an overcomplete dictionary signal representation as well as the concept of successive interference cancellation for multi-user detection. We introduce the algorithm for multiple access UWB signal detection, and present guidelines to generate overcomplete dictionaries for the detection of signals in noise. The proposed detection algorithm for multiple access UWB systems can eliminate noise as well as multi-user interference (MUI). Signal detection is achieved by solving an l 1 norm minimization problem, which can be calculated using low complexity linear programming algorithms.

Ultra-wide-band (UWB) is expected to enable highspeed short-range wireless connectivity of numerous devices in the consumer application space. It is also a very promising candidate technology for medical applications. However, a good understanding of the performance of the technology in the medical application environment is essential. In this paper, we present the results of the study on the effects of human body interfering with (blocking) the UWB radio signal, focusing on the performance of the WiMedia UWB technology for medical applications. The study includes channel measurements, modeling and performance evaluation using the channel models. The impact of human blockages on the wireless link is studied via system simulations for different UWB configurations, including the standard WiMedia UWB system with single receive (RX) antenna, (co-located) receive antenna selection system, and the (separately-located) device selection system. Link margin analysis is also performed to quantitatively evaluate the link robustness of different UWB setups against human blockages.

To improve the performance of the ultra-wideband (UWB) system against multiple interferences existed in wireless personal area network (WPAN), such as narrowband interference (NBI), multiple-access interference (MAI), and multipath interference (MI), we present an orthogonal complementary code (OCC)-based UWB system with modified chirp waveforms. Considering the time–frequency characteristics of the chirp functions and the principle of NBI suppression, we first propose the modified linear and nonlinear chirp function-based flexible UWB pulses to suppress the multiple NBIs. Furthermore, with the implementation of OCC spread modulation, the modified chirp waveform-based UWB system is presented to effectively alleviate the influence of the MAI and MI. Simulation results and analysis validate the efficiency of the modified chirp pulse-based OCC-UWB system in the suppression of NBIs, MAI, and MI.

A compact microstrip patch antenna for ultra-wideband (UWB) applications is proposed. The antenna has a frequency bandwidth of 3.03GHz (4.73GHz–7.76GHz). The microstrip antenna has a planar geometry and consists of two patches, a circular radiating patch and a circular ring shaped parasitic patch. The design was simulated with the help of IE3D v.14 software and the different parameters of the patch antenna were computed. Results show that the proposed antenna has promising characteristics for UWB applications such as Wireless Personal Area Network (WPAN), microwave imaging for detecting tumors and cancers, home networking etc.

The explosive growth of the Internet over the last decade has led to an increasing demand for high-speed, ubiquitous Internet access. Broadband wireless technologies are increasingly gaining popularity by the successful global deployment of the wireless personal area networks (Bluetooth-IEEE 802.15.1), wireless local area networks (WiFi- IEEE 802.lln), and wireless metropolitan area networks (WiMAX- IEEE 802.16). New ICT and e-Learning strategies and advances in wireless standards and technologies- particularly in the areas of Bluetooth, WiFi (wireless fidelity), WiMAX (worldwide interoperability for microwave access) and mobile computing can help to bridge the digital divide in education and research. Using open broadband Wireless technologies and implementing mobile computing architectures, one can overcome the challenges of ground, infrastructure, and finance to increase access; deploy broadband quickly and cost-effectively to areas currently not served; and extend the benefits of digital revolution to previously unreachable populations. These technologies aim to provide low-cost, high-performance Wireless access to residential and business applications. As technology evolves to address portable and mobile applications, the required features and performance of the system will increase. Evolution toward the phase called "full mobility" provides incremental support for low latency, low packet loss and real-time handoff of subscriber terminals operating at high speeds. This paper presents the analogy of promising wireless technologies on different frequencies: Bluetooth, WiFi, and WiMAX. This paper is organised into four parts: part I describes the functionality and usage of Bluetooth in the wireless personal area networks, part II presents the WiFi- IEEE 802.1 In strategies for users considering higher-bandwidth alternatives to existing wireless personal area networks, part III discusses how the WiMAX is used as a current standard for Wireless data transmission technology, which is optimized to deliver high, bursty data rates to mobile subscribers, and to support real-time multimedia and Voice over IP (VoIP) applications, and part-TV explores how these emerging Wireless technologies differ from one another.

The throughput of WPAN (Wireless Personal Area Network) based on Bluetooth was decided by the interference of Bluetooth piconets in the network. The interference was decided by the hamming correlation of Bluetooth FH (Frequency Hopping) selected sequence. In order to improve the WPAN throughput, the WPAN model and data packet collision model were built and the relations about WPAN throughput, the maximum hamming correlation of FH selected sequence, the numbers of Bluetooth piconets and the SNR of channel were analyzed. The functions of WPAN throughput were deduced. After analyzing the performance of Bluetooth FH selected sequence, the original algorithm was replaced by the AES (Advanced Encryption Standard) algorithm. The theoretical analysis proved that the AES FH sequences selected algorithm could improve the WPAN throughput. The simulation results proved the theoretical analysis. The test result with ARM926EJs SoC (System on Chip) + RF (Radio Frequency) chip nRF2401 and CSR's Bluecore4 Bluetooth module got the same conclusion. All of these could prove that the AES algorithm can improve the WPAN throughput efficiently.

In this paper, a multi-hop range conflict-free resource reservation scheme for UWB (Ultra Wide Band) WPAN (Wireless Personal Area Network) with D-MAC (Distributed Medium Access Control) is proposed. Unlike the centralized IEEE 802.15.3 MAC, the D-MAC UWB specified by WiMedia Alliance supports DRP (Distributed Reservation Protocol) mechanism which makes all devices be self-organized and removes the SOP (Simultaneous Operating Piconet) problem, i.e., packet collisions between overlapped piconets in the centralized IEEE 802.15.3 MAC. However, since each device's mobility perspective in multi-hop environment has not been taken into account in the current WiMedia D-MAC, it may cause a "mobile" hidden node problem. In addition, once a DRP conflict occurs due to the mobile hidden node problem, only one of the DRP reservations involved in that DRP conflict maintains the reserved MASs, while the other DRP reservations must be terminated and DRP negotiations for them have to be re-started although only a few MASs are overlapped. Such DRP termination and renegotiation time delays due to the DRP conflicts can be a critical problem to the mobile devices transceiving real-time QoS traffic streams. Therefore, we propose a mechanism to prevent and resolve multi-hop range DRP conflicts due to each device's mobility in D-MAC environment and demonstrate its guaranteed Seamless QoS and prioritized real-time QoS performances via numerical analyses.

Certified Wireless Universal Serial Bus (WUSB) is one of different varieties of Wimedia standard for distributed medium access control (MAC) protocol for ultra wide band (UWB) communications in the wireless personal area network (WPAN). To the best of our knowledge, no technical contributions exist in the open literature at present simulating WUSB and its performance. In this paper, we investigated the performance of the WUSB standards and compared it to the Wimedia Standard using NS-2. The study showed that WUSB can achieve better throughput and more accurate timing control of device activity than using the standard facilities of the WiMedia MAC. Our paper also addressed protocol extensions and improvement to the original WUSB standard to support better Quality of Service (QoS) by adding priority, adaptive packet loss technique and adding backup host selection to prevent mobility failures.

Wireless personal area networks (WPANs) are becoming a popular way of networking computer equipments in the home and office. In order to support differentiated quality-of-service (QoS) in WPANs, the ECMA-368 prioritized contention access (PCA) protocol allocates multiple access categories (ACs) with different priorities, inter-frame spaces, and contention window sizes. This paper presents an improved medium access control (MAC) scheme to enhance the QoS of WPANs based on the idea of using the different increasing functions for each AC to enlarge the size of contention window in the case of transmission collision. The performance of this improved scheme under multimedia applications is extensively investigated and compared with the original ECMA-368 PCA using the well-known network simulator NS-2. The results show that this scheme is able to achieve higher throughput and medium utilization than the original ECMA-368 PCA. Moreover, it provides a good prioritization level between multiple ACs.