UWB radio module design for wireless sensor networks

In this paper, we describe an impulse-based ultra wideband (UWB) radio system for wireless sensor network (WSN) applications. Different architectures have been studied for base station and sensor nodes. The base station node uses coherent UWB architecture because of the high performance and good sensitivity requirements. However, to meet complexity, power and cost constraints, the sensor module uses a novel non-coherent architecture that can autonomously detect the UWB signals. The radio modules include a transceiver block, a baseband processing unit and a power management block. The transceiver block includes a Gaussian pulse generator, a multiplier, an integrator and timing circuits. For long range applications, a wideband low noise amplifier (LNA) is included in the transceiver of the sensor module, whereas in short range applications it is simply eliminated to further reduce the power consumption. In order to verify the proposed system concept, circuit level implementation is studied using 1.5 V 0.18 μm CMOS technology. Finally, the UWB radio modules have been designed for implementation in liquid-crystal-polymer (LCP) based System-on-Package (SoP) technology for low power, low cost and small size integration. A small low cost, double-slotted, Knight’s helm antenna is embedded in the LCP substrate, which shows stable characterization and a return loss better than ?10 dB over the UWB band.     

UWB wireless sensor networks: UWEN - a practical example

The research topic of sensor networks has been around for some time. With improvements in device size, power consumption, communications, and computing technology, sensor networks are becoming more popular for an ever increasing range of applications. Since 2002, there has been an increased in the popularity of commercial applications based on ultra wideband. This, in turn, has ignited interest in the use of this technology for sensor networks and fuelled research in the area. Impulse-radio-based UWB technology has a number of inherent properties that are well suited to sensor network applications. In particular, UWB systems have potentially low complexity and low cost, have noise-like signal, are resistant to severe multipath and jamming, and have very good time domain resolution allowing for location and tracking applications. This article examines one example of a UWB sensor network for outdoor sport and lifestyle applications.     

A CMOS ultra-wideband impulse radio transceiver for 1-mb/s data communications and /spl plusmn/2.5-cm range finding

A CMOS ultra-wideband impulse radio (UWB-IR) transceiver was developed in 0.18-/spl mu/m CMOS technology. It can be used for 1-Mb/s data communications as well as for precise range finding within an error of /spl plusmn/2.5 cm. The power consumptions of the transmitter and receiver for data communication are 0.7 and 4.0 mW, respectively. When an LNA operates intermittently through bias switching, the power consumption of the transceiver is only 1 mW. The range for data communication is 1 m with BER of 10/sup -3/. For ranging applications, the transmitter can reduce the power to 0.7 /spl mu/W for 1k pulses per second, and the receiver consumes little power. The transceiver design, all-digital transmitter, and intermittent circuit operation at the receiver reduce the power consumption dramatically, which makes the transceiver well suited for applications like sensor networks. The electronic field intensity is lower than 35 /spl mu/V/m, and thus the UWB system can be operated even under the current Japan radio regulations.     

一种适用于无线传感器通信的UWB收发机结构

论文介绍了一种使用低速率超宽带技术实现的适用于无线传感器网络通信的收发机结构,这种结构采用结构简单的IR-UWB(Impulse Radio UWB)方法,能满足无线传感器节点低功耗、低硬件复杂度的要求。这种结构发射机采用SRD(Step Recovery Diode)二极管来产生UWB脉冲信号,接收机则使用结构简单的能量检测方法。     

A Pulse Generator for UWB-IR Based on a Relaxation Oscillator

We propose the adaptation of a well-known relaxation oscillator to produce a modulated Gaussian pulse suitable for ultra-wide-band (UWB) impulse radio (IR). The proposed circuit has low area and low power consumption, can easily be modulated by a digital signal, and requires no special technology options; these features make it suitable for UWB-IR low-cost applications. The circuit behavior is confirmed by simulation and by experimental results on a prototype designed in austriamicrosystems 0.35-mum SiGe-BiCMOS technology.     

Ultra-wide-band transmitter for low-power wireless body area networks: design and evaluation

The successful realization of a wireless body area network (WBAN) requires innovative solutions to meet the energy consumption budget of the autonomous sensor nodes. The radio interface is a major challenge, since its power consumption must be reduced below 100 /spl mu/W (energy scavenging limit). The emerging ultra-wide-band (UWB) technology shows strong advantages in reaching this target. First, most of the complexity of an UWB system is in the receiver, which is a perfect scenario in the WBAN context. Second, the very little hardware complexity of a UWB transmitter offers the potential for low-cost and highly integrated solutions. Finally, in a pulse-based UWB scheme, the transmitter can be duty-cycled at the pulse rate, thereby reducing the baseline power consumption. We present a low-power UWB transmitter that can be fully integrated in standard CMOS technology. Measured performances of a fully integrated pulse generator are provided, showing the potential of UWB for low power and low cost implementations. Finally, using a WBAN channel model, we present a comparison between our UWB solution and state-of-the-art low-power narrow-band implementations. This paper shows that UWB performs better in the short range due to a reduced baseline power consumption.     

一种基于新型同步算法的脉冲UWB能量检测接收器设计

在RFID和无线传感器网络等应用系统中,脉冲UWB(IR-UWB)技术的低功耗和低成本特点具有很大的优势。为了有效地降低功耗和成本,采用了一种基于能量检测,使用开关键控(OOK)调制的IR-UWB接收器,提出了一种使用能量补偿与自适应门限的新型同步与检测算法,此算法降低了接收器的能耗与硬件复杂度。通过对该接收器的仿真及用FPGA硬件实现,表明此算法降低了同步时的功耗及前导序列长度,提高了传输效率,同时保持了系统性能。测试结果表明此接收器架构能够满足在数据率10Mb/s时,功耗仅为1nJ/bit左右,具有低功耗、低复杂度的特点。     

UWB Direct Chaotic Communication Technology for Low-Rate WPAN Applications

The goal of this paper is to describe the design of an ultrawideband (UWB) system that is optimized for low-complexity, low-power, low-cost, and low-rate wireless personal area network applications. To this aim, we propose a system based on novel direct chaotic communication (DCC) technology, in which a 2-GHz-wide chaotic signal is directly generated into the lower band of the UWB spectrum. Based on this system, two simple modulation schemes, namely, chaotic on-off keying and differential chaos-shift keying, are studied, and the performance of both noncoherent and differential-coherent transceiver architectures is evaluated. Various system design parameters and tradeoffs are discussed throughout the paper, including frequency band plans, data throughput, and system scalability. In particular, the frequency-division multiplexing technique is proposed as a low-cost alternative to achieving simultaneous operating piconets for short-distance applications. The average power consumption for various operating data rates and the technical feasibility of implementing the DCC system as a low-cost integrated circuit are also addressed. Finally, Monte Carlo simulations are performed based on the IEEE 802.15.4a standard channel models to evaluate the performance of the two modulation schemes. In general, both schemes experience little degradation under multipath environments due to the self-inherent wideband characteristic of the chaotic signal.     

Analysis and design of a frequency-hopped spread-spectrumtransceiver for wireless personal communications

Personal communications services (PCS) require low-power radio technologies. One such transceiver architecture employing frequency-hopped spread-spectrum techniques is presented. System features such as antenna diversity with equal-gain combining and sequential hop combining are incorporated into the transceiver design to achieve robust wireless digital data transmission over fading channels. A direct-conversion architecture from radio frequency (RF) to baseband reduces the overall power consumption by eliminating intermediate frequency (IF) components. High-rate frequency hopping with frequency-shift keying (FSK) modulation is implemented using a direct digital frequency synthesis technique. A multiplierless correlation FSK detector, suitable for direct-conversion receivers, has been designed for quadrature noncoherent detection. Robust acquisition algorithms based on energy detection and pattern matching and tracking architectures using digital phase-locked loops are also described for system synchronization. The proposed transceiver is well-suited for low-power PCS applications and other portable wireless communications     

Low-Complexity Ultra-Wide-Band Communications

Low-complexity low-power ultra-wide-band (UWB) radios are required for low data rate (LDR, < 100 kbps) short- range applications. Potential low-power air interface candidates are impulse radio UWB and FM-UWB. The use of simple (noncoherent) radio architectures, a low supply voltage and duty cycling pave the way to low power consumption. Interference mitigation is an important requirement for today's UWB receivers. Processing gain and filtering may be applied in the physical layer, whereas detect and avoid strategies work at MAC level. Constant-envelope FM-UWB uses high modulation index analog FM for spreading. Instantaneous despreading in the receiver, combined with processing gain make this system an interesting option for robust LDR personal area network systems.     

基于SOC的单芯片无线收发系统设计

在无线收发系统电路结构的基础上,分析了基于片上系统(SOC)的单芯片无线电通信最重要的收发部分的设计原理。给出了单芯片无线电的基本结构及电路实现的若干组成部分(混频器、低噪音放大器和功率放大器等)的解决方案。利用单芯片无线电体积小、低功耗、成本低和可靠性高的优点,在无线传感器网络、蓝牙技术与无限局域网(WLAN)方面具有广泛的应用。     

A 750 Mb/s, 12 pJ/b, 6-to-10 GHz CMOS IR-UWB Transmitter With Embedded On-Chip Antenna

This paper presents a novel impulse radio based ultra-wideband transmitter. The transmitter is designed in 0.18 mum CMOS process realizing extremely low complexity and low power. It exploits the 6-to-10 GHz band to generate short duration bi-phase modulated UWB pulses with a center frequency of 8 GHz. No additional RF filtering circuits are required since the pulse generator circuit itself has the functionality of pulse shaping. Generated pulses comply with the FCC spectral emission mask. Measured results show that the transmitter consumes 12 pJ/b to achieve a maximum pulse repetition rate of 750 Mb/s. An optional embedded on-chip antenna and a power amplifier operating in 6-10 GHz band are also designed and investigated as a future low cost solution for very short distance IR-UWB communications.     

一种基于OFDM的新型低功耗RF收发器设计

为实现低功耗信号传输,提出一种基于OFDM的IEEE 802.15.4g低功耗无线电频率（RF）收发器。该新型RF收发器电路由Tx BBA（基带模拟）、片上RF开关前端、Rx BBA及锁相环（PLL）构成,采用0.18?m CMOS技术制作,满足了IEEE 802.15.4g OFDM系统低功耗信号传输的需要。实际测试结果显示,相比传统的RF收发器,提出的RF收发器具有较低的功耗和良好的灵敏度,当电源电压为1.8 V时,Tx模式下会消耗14.7mA,Rx模式下会消耗15.7mA。     

FM-UWB for Communications and Radar in Medical Applications

UWB technology is a useful and safe new technology in the area of wireless body area network. There are many advantages of using UWB as a communication standard for biomedical applications. Due to very low radiated power (−41.3 dBm/MHz), low power consumption, good coexistence with the other existing instruments, Robustness to interference and multipath. Moreover, one specific UWB technology, namely Frequency Modulated (FM)-UWB, has also an important advantage, which make it even more convenient for medical applications, such as simple low cost design (FM, no receive LO, no carrier synchronization as in IR-UWB). UWB technology has been also proposed radar applications such as: Non-Invasive Heart and Respiration Rate Monitoring; Detection of Cardiac Arrhythmias; Detection of Pathological Respiratory Patterns, particularly in Sudden Infant Death Syndrome (SIDS) and Sleep Apnea; Multi-Patient Monitoring; Detection and Non-Invasive Imaging of Breast Tumors. However, pulsed radar are mainly used for these applications. The main issue that is addressed in this paper is the integration of sensing and communication using FM-UWB and radar technology so that a single device can be obtained for two different operational mode. We have show that FM-UWB as radar can meet the requirements of typical biomedical applications such as Non-Invasive Heart and Respiration Rate Monitoring. Advantages and challenges of this integration are shown. Future perspectives of this novel activity will be drawn.     

A 3.1 to 5 GHz CMOS Transceiver for DS‐UWB Systems

This paper presents a direct‐conversion CMOS transceiver for fully digital DS‐UWB systems. The transceiver includes all of the radio building blocks, such as a T/R switch, a low noise amplifier, an I/Q demodulator, a low pass filter, a variable gain amplifier as a receiver, the same receiver blocks as a transmitter including a phase‐locked loop (PLL), and a voltage controlled oscillator (VCO). A single‐ended‐to‐differential converter is implemented in the down‐conversion mixer and a differential‐to‐single‐ended converter is implemented in the driver amplifier stage. The chip is fabricated on a 9.0 mm² die using standard 0.18 µm CMOS technology and a 64‐pin MicroLead Frame package. Experimental results show the total current consumption is 143 mA including the PLL and VCO. The chip has a 3.5 dB receiver gain flatness at the 660 MHz bandwidth. These results indicate that the architecture and circuits are adaptable to the implementation of a wideband, low‐power, and high‐speed wireless personal area network.     

UWB-based sensor networks for localization in mining environments

Wireless sensor networks (WSN) have attached a great attention in the last few years. WSN offer several advantages over the traditional sensor networks, such as elimination of costly wires, security and larger area coverage. In the last few years, there has been great interest commercial applications based on Ultra Wideband (UWB). It has potentially low complexity, low cost and an excellent time domain resolution which facilitates location and tracking applications. Therefore, UWB provide a good combination of high performance with low complexity for WSN applications. Localization has attracted considerable attention in many fields. Accurate estimation of an individual location can be a difficult task, producing ambiguous results particularly in harsh environment. In this paper, we focus on feasibility study (via simulation and measurements) of using UWB based-WNS as future solution for localization in underground mines.     

On the Performance of UWB-IR With Interleaved Coding Modulation and Polarity Randomization on AWGN and Multipath Fading Channels

One of the main challenges in designing high-data-rate ultrawideband impulse radio (UWB-IR) systems is their sensitivity to intersymbol and interpulse interferences, which may significantly degrade the performance. This paper deals with new methods of protection against errors for UWB-IR systems operating in severe multipath interference-prone environments. The proposed and investigated techniques include interleaved coding modulation and polarity randomization applied in combination with superorthogonal convolutional coding or frame repetition. The performance of high-data-rate (125 Mb/s) coded UWB-IR systems is evaluated on the additive white Gaussian noise and realistic UWB channels that have recently been proposed by the IEEE. Our UWB-IR system incorporates a differential autocorrelation receiver, allowing for a simple hardware architecture. Through theoretical analysis of the bit error rate (BER) and the use of Monte Carlo simulations, we demonstrate that the application of the proposed methods may lead to significant performance improvements.      

Intermittent Operation Control Scheme for Reducing Power Consumption of UWB-IR Receiver

A low power ultra-wideband impulse radio (UWB-IR) receiver was developed in 0.18-mum CMOS. All circuits of the receiver AFE operate intermittently with a sampling clock of an analog-digital converter (ADC). The sampling rate of the ADC is equal to the pulse repetition frequency of the received signals. Power consumption of the receiver AFE is reduced by 60% using a developed intermittent operation scheme without degrading of receiver sensitivity. As a result, the power consumption of the receiver AFE is 38 mW. The receiver has a data rate of 258 kb/s over a distance of 52 m and of 10.7 Mb/s over a distance of 14 m.     

A CMOS IR-UWB Transceiver Design for Contact-Less Chip Testing Applications

This paper presents a novel CMOS impulse radio (IR) ultra-wide-band (UWB) transceiver system design for future contact-less chip testing applications using inductive magnetic coupling as wireless interconnect. The proposed architecture is composed of a simple and robust design of a Gaussian monocycle impulse generator at the transmitter, a wideband short-range on-chip transformer for data transmission, and a g_m-boosted common-gate low-noise amplifier in the UWB receiver path. SpectreRF post-layout simulation with a 90-nm CMOS technology shows that the transceiver operates up to a 5 Gb/s data rate, and consumes a total of 9 mW under a 1-V power supply.     

UWB雷达芯片的研究现状与发展

超宽带(UWB)系统具有高传输速率、低功耗、探测精度高、穿透性强、安全性高等优势,在军事、雷达、生物探测、短距通信及室内室外高精度定位等场景有着广泛的应用.并且随着半导体技术的发展,基于CMOS的UWB雷达芯片成为研究热点.国内外众多学者及商业公司提出各具优势的UWB芯片及系统.该文从UWB系统、UWB芯片架构中关键电...