Impulse Radio Ultra-wideband Transceiver Research Articles

An IR-UWB Multi-Sensor Approach for Collision Avoidance in Indoor Environments

This article aims to propose new techniques to detect and distinguish humans from moving machines in indoor environments. Although many research efforts have been already dedicated to humans’ indoor detection, most of the work has been focused on counting people and crowd measurement for consumer business applications. Our objective is to develop a reliable approach for humans’ indoor detection and localization aiming at avoiding collisions inside a mixed Industry 4.0 manned and unmanned environment to enhance personal and equipment safety and to prevent unwanted intrusions. An original aspect of our research is that we have worked on the real-time estimation of humans’ and moving machines’ positions while addressing the problems of multipath components and noise clutter detection. A multipulse constant false alarm rate detection algorithm is also proposed for removing the misdetections due to heavy clutter components in the indoor environment. Four impulse radio ultrawideband transceivers are placed in a specific geometry and data fusion is performed to reduce the influence of multipath and noise on the detection process. A convolutional neural network (CNN) is then used to extract the patterns corresponding to a moving machine and humans and classify them accordingly. Experiments have been carried out in two different indoor environments to demonstrate the performance of the proposed algorithms.

An Optimized IR-UWB Communication System with Interference Reduction on a Narrowband System Using Genetic Algorithm

This paper proposed a new impulse radio ultra wideband (IR-UWB) signal to reduce interference on narrowband systems at high usage 5.2 GHz frequency. The combination of 4th and 5th order derivatives of Gaussian pulses were employed to generate the signal so that satisfy the US Federal Communications Commission (FCC) mask. The genetic algorithm technique was used to find the pulse optimized parameters. In this paper, spectrum was optimized by changing the shape factor (sigma) and amplitude of Gaussian pulses so that the transmitted power spectrum density was minimized at a frequency of 5.2 GHz and maximized at the other frequencies from 3.1 to 10.6 GHz according to the FCC mask. The signal was applied in an IR-UWB transceiver system with binary-phase shift keying modulation. The IR-UWB waveform is generated by a programmable digital to analog based circuit. The proposed system was compared with conventional IR-UWB systems at the same condition. The simulation results in multipath channel showed that the proposed system not only reduced interference with the narrowband system, but also this was robust against narrowband interference at 5.2 GHz frequency.

A Fully Integrated Programmable 6.0–8.5-GHz UWB IR Transmitter Front-End for Energy-Harvesting Devices

Ultra-wideband impulse radio transceivers are becoming a key building block for establishing ultralow power wireless sensor networks. However, impulse radio transmitters commonly suffer from a low spectral quality and a coarse frequency tuning resolution, which limits their global applicability. In this article, we present a fully integrated ultralow power impulse radio transmitter front-end (TFE) whose pulse shaping capabilities and integrated output matching network make it globally applicable up to a 4-MHz pulse repetition rate. We demonstrate a digital carrier frequency-tuning method that achieves a 28-MHz resolution over the frequency band of 6.0–8.5 GHz. In addition, we show that the temperature dependence of the TFE’s carrier frequency can be compensated digitally over the industrial temperature range from −40°C to 85 °C. The proposed TFE supports energy-harvesting applications particularly well due to its low leakage power level of 380 nW and a high tolerance to power supply transients during pulse generation. It is demonstrated to operate robustly with low-drive regulators powered by low-quality sources. The TFE is fabricated in a 65-nm CMOS process. It generates 1.8-pJ pulses at a 7.5-GHz carrier frequency while consuming 63 pJ per pulse, corresponding to 2.3% efficiency.

Compact digital implementation of a non‐coherent IR‐UWB transmitter and receiver

Non-coherent impulse-radio ultra-wideband (IR-UWB) transceivers are attractive candidates for applications where the silicon area and power consumption are relatively limited. This study presents the compact digital architecture design and implementation of a non-coherent IR-UWB transmitter and receiver based on the energy detection scheme, including the synchroniser module. The software models of the designed transceiver are simulated and verified in both floating-point and fixed-point numerical representations. The synthesisable Verilog description of the transmitter and receiver architectures is simulated and verified against their fixed-point simulation model. The transmitter and receiver are implemented in the authors custom-developed field-programmable gate array (FPGA) board. The bit error rate performance of the transmitter and receiver is measured in real-time on the FPGA, utilising an accurate on-chip Gaussian noise generator. The characteristics and implementation results of the transmitter and receiver architecture on the FPGA are presented. An application-specific integrated circuit (ASIC) architecture of the IR-UWB transceiver is estimated to occupy 0.0227 mm 2 and dissipate 760 mW from a 1.0 V supply while operating at 82 MHz in a standard 32 nm complementary metal-oxide-semiconductor technology.

A Time-Based Angle-of-Arrival Sensor Using CMOS IR-UWB Transceivers

In this paper, we present a time-based angle-of-arrival (AoA) sensor using the impulse-radio ultra-wideband (IR-UWB) technology. Arrival angles are estimated using the time difference of the received signal, which is transmitted from a target between two IR-UWB receivers. The most salient feature of this system is high precision angle estimation, which is possible with simple and compact hardware, because its operation is based on a time-based approach. The receiver in the AoA sensor consumes 50 mA at 1.2 V supply voltage and the sensitivity is -61 dBm. The measurement result shows that angle error is lower than ±1°.

A Low-Energy Ultra-Wideband Internet-of-Things Radio System for Multi-Standard Smart-Home Energy Management

This work presents an Internet of Things (IoT) system for home energy management based on a custom-designed Impulse Radio Ultra-Wideband (IR-UWB) transceiver that targets a generic and multi-standard control system. This control system enables the interoperability of heterogeneous devices: it integrates various sensor nodes based on ZigBee, EnOcean and UWB in the same middleware by utilizing an ad-hoc layer as an interface between the hardware and software. The paper presents as a first the design of the IR-UWB transceiver for a portable sensor node integrated with the middleware layer, and also describes the receiver connected to the control system. The custom-designed low-power transmitter on the sensor node is fabricated with 130 nm CMOS technology. It generates a signal with a 1.1 ns pulse width while consuming 39 μW at 1 Mbps. The UWB sensor node with a temperature measurement capability consumes 5.31 mW, which is lower than the power level of state-of-the-art solutions for smart-home applications. The UWB hardware and software layers necessary to interface with the control system are verified in over-the-air measurements in an actual office environment. With the implementation of the presented sensor node and its integration in the energy management system, we demonstrate achievement of the broad flexibility demanded for IoT.

Impulse radio ultra wideband wireless transmission of dopamine concentration levels recorded by fast-scan cyclic voltammetry.

This paper demonstrates the feasibility of utilizing impulse radio ultra wideband (IR-UWB) signaling technique for reliable, wireless transmission of dopamine concentration levels recorded by fast-scan cyclic voltammetry (FSCV) at a carbon-fiber microelectrode (CFM) to address the problem of elevated data rates in high-channel-count neurochemical monitoring. Utilizing an FSCV-sensing chip fabricated in AMS 0.35μm 2P/4M CMOS, a 3-5-GHz, IR-UWB transceiver (TRX) chip fabricated in TSMC 90nm 1P/9M RF CMOS, and two off-chip, miniature, UWB antennae, wireless transfer of pseudo-random binary sequence (PRBS) data at 50Mbps over a distance of <;1m is first shown with bit-error rates (BER) <; 10(-3). Further, IR-UWB wireless transmission of dopamine concentration levels prerecorded with FSCV at a CFM during flow injection analysis (FIA) is also demonstrated with transmitter (TX) power dissipation of only ~4.4μW from 1.2V, representing two orders of magnitude reduction in TX power consumption compared to that of a conventional frequency-shift-keyed (FSK) link operating at ~433MHz.

A cross-layer energy efficiency optimization model for WBAN using IR-UWB transceivers

An energy efficiency optimization model for the IEEE 802.15.6 standard based wireless body area network is described in this paper. Cross-layer approach has been used here by focusing on physical (PHY) and medium access control (MAC) layers taking into account relevant characteristics therein. Studied PHY is based on impulse radio ultra wideband (IR-UWB) signaling with mandatory on---off keying modulation and non-coherent energy detection receiver. The analyzed MAC protocol is slotted Aloha which is used in the contention based mode of the IEEE 802.15.6 std. using IR-UWB PHY. The proposed model can be used to compare the energy efficiency of uncoded and coded transmissions using different Bose---Chaudhuri---Hocquenghem code rates. The model enables joint code rate and packet length optimization in AWGN channel when using the path loss model for hospital scenario, defined by the IEEE P802.15 working group. Results clearly show the most energy efficient code rate and packet length as a function of distance.

A Sub-GHz Mostly Digital Impulse Radio UWB Transceiver for Wireless Body Sensor Networks

This paper presents a mostly digital impulse radio (IR) ultra-wideband (UWB) transceiver for low power wearable and implantable biomedical devices. The UWB transmitter adopts carrier-less all-digital pulse generator with on-off keying (OOK) modulation, and uses an 11-bit Barker code for reliable communication in the frequency range of 0-960 MHz. The receiver is based on auto-threshold detection. The only RF block in the receiver is the low-noise amplifier (LNA), and this LNA operates intermittently for better power efficiency. The timing window for incoming data is provided by a delay locked loop (DLL). This DLL could synchronize the receiver clock to the incoming data. Fabricated in a standard 0.35- μm CMOS technology, the prototype chip achieves energy efficiency of 100 and 600 pJ/pulse for the transmitter and receiver, respectively.

No Communication Nodes Synchronization for a Low Power Consumption MAC Protocol in WSN based on IR-UWB

Synchronization is an important issue in multi hops Wireless Sensor Networks (WSN). Such networks are known by their limited resources of energy, storage, computation, and bandwidth. In addition if the networks entities are deployed with high density, it makes the synchronization mandatory for these networks. Impulse Radio Ultra Wide Band (IR-UWB) technology is a promising solution for this kind of networks due to its various advantages such as its robustness to severe multipath fading even in indoor environments, its low cost, low complexity, and low power consumption. To exploit the specific features of this technology, we need a convenient MAC protocol. WideMac was presented as a new low power consumption MAC protocol designed for WSN using IR-UWB transceivers. Because of the luck of synchronization in this protocol, this paper presents a solution for the synchronization problem especially in the case of no communication between the Network’s nodes. To implement and evaluate the proposed synchronization mechanism, we used MiXiM platform under OMNet++ Simulator.

An Investigation of Total Ionizing Dose Damage on a Pulse Generator Intended for Space-Based Impulse Radio UWB Transceivers

We investigate, for the first time, the effects of total ionizing dose (TID) on a CMOS pulse generator implemented in a SiGe BiCMOS platform, and which is intended for use in space-based impulse radio ultra-wideband transceivers. The pulse generator was fabricated in Jazz Semiconductor's SBC18-H3 SiGe BiCMOS process technology, which combines 250 GHz SiGe HBTs and 180 nm CMOS. Total dose effects were examined using a 10-keV X-ray source. The effects of the TID on the performance of the pulse generator were investigated and a compensation scheme for mitigating these radiation effects is proposed.

0.15-nJ/b 3–5-GHz IR-UWB System With Spectrum Tunable Transmitter and Merged-Correlator Noncoherent Receiver

Carrierless impulse radio ultra-wideband (IR-UWB) radios have attracted significant research interest due to their low system complexity and power consumption. Unfortunately, IR-UWB systems suffer from the difficulty in controlling the transmitted spectral mask because of process, voltage, and temperature variations. In this paper, a monolithic 3-5-GHz IR-UWB transceiver is presented that integrates both amplitude and spectrum tunability, thereby providing adaptable spectral characteristics for different data rate transmission. The noncoherent receiver employs a simplified low-power merged correlator, eliminating the need for a conventional sample-and-hold circuit. After self-correlation, the demodulated data is digitally synchronized with the baseband clock. The 4 mm2 0.13 μm CMOS transmitter and receiver consume 2.2 and 13.2 mW, respectively at the data rate of 100 Mb/s. The measured peak-to-peak transmitted pulse amplitudes are 240, 170, and 115 mV, with a tunable frequency range of 3.2-4.1 GHz. The receiver exhibits a maximum gain of 70 dB, noise figure of 8.6 dB, and the input 1-dB compression point of -28 dBm . With off-chip antennas, the transceiver achieves a bit error rate of 10-3 at a sensitivity of -50 dBm.

A 2-Gb/s 130-nm CMOS RF-Correlation-Based IR-UWB Transceiver Front-End

This paper presents a carrierless RF-correlation-based impulse radio ultra-wideband transceiver (TRX) front-end in a 130-nm CMOS process. Timing synchronization and coherent demodulation are implemented directly in the RF domain, targeting applications such as short-range energy-efficient wireless communication at gigabit/second data rates. The 6-10-GHz band is exploited to achieve higher data rate. Binary phase-shift keying modulated impulse is generated by edge combining the delayed clock signal at a lower frequency of 2 GHz to avoid a more power-hungry phase-locked loop at higher frequency (e.g., 8 GHz). An on-chip pulse shaper inside the pulse generator is designed to provide filtering for an edge-combined signal to comply with the Federal Communications Commission spectrum emission mask. In order to achieve 25-ps delay accuracy and 500-ps delay range for the proposed two-step RF synchronization, a template-based digital delay generation scheme is proposed, which delays the locally generated trigger pulse instead of the wideband pulse itself. Occupying 6.4 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of chip area, the TRX achieves a maximum data rate of 2 Gb/s and a receiver (RX) sensitivity of -64 dBm with a bit error rate of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-5</sup> , while requiring only 51.5 pJ/pulse in the transmitter mode and 72.9 pJ/pulse in the RX mode.

Accurate TOA Estimating UWB-IR Transceiver for Ranging System in Multi-Path Environment

In this work, an ultra-wideband impulse radio (UWB-IR) transceiver with accurate time-of-arrival (TOA) estimation for a ranging/positioning system was developed for wireless sensor network applications. The system uses an impulse radio characterized by a low duty cycle and direct-sequence spreading, which enable very precise ranging and good receiver sensitivity. An algorithm enabling the TOA of the first-path signal to be measured accurately in a multi-path environment with simple, low-power and low cost implementations was proposed. UWB chips with CMOS 0.18-μm technology and UWB transceiver modules performed that the accuracy of the proposed ranging system is 18.5 cm in a closed space.

UWB-IR Wireless Accurate Location System for Sensor Network

An original asynchronous Ultra Wideband — Impulse Radio (UWB-IR) wireless location system for sensor network is developed and evaluated through experiments. The system enables wireless nodes to be located and communicated with simultaneously at low power and low cost. The proposed system does not need system synchronization. Each access point of the proposed location system measures the time difference between two signals' received timing: one is from target node, and the other is from an access point, the position of which is already known. Then the position of the target nodes is calculated by a pseudo Time Difference of Arrival (TDOA) method. We first introduce the system configuration and asynchronous TDOA method adopted in this system. Next, we estimate the received-signal-timing measurement accuracy of UWB-IR signal and evaluate it in experiments using prototype UWB-IR transceivers. Then we estimate the location accuracy by the horizontal dilution of precision (HDOP) metric and show the field trial results of using the prototype UWB-IR location system.

A 52-mW 3.1–10.6-GHz Fully Integrated Correlator for IR-UWB Transceivers in 0.18 $\mu\hbox{m}$ CMOS

Correlators play key roles in impulse radio ultrawideband (IR-UWB) transceivers. Multiplier-based correlator performs correlation-type demodulation in addition to select desired UWB signals by correlating incoming pulses with templates. This paper reports design and implementation of a fully integrated low-power broadband multiplier-based correlator for a 3.1-10.6-GHz fullband IR-UWB receiver in 0.18 μm CMOS that consists of a UWB multiplier core, two UWB pulse generators, single-ended-to-differential-ended converter, a first-order <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RC</i> integrator with a 200-MHz bandwidth, and a buffer. Measurement results confirm desired correlation-type demodulation and correlation functions with a conversion gain of 11.03 dB, noise figure of 15.7 dB, very low power consumption of 52 mW and a 1-dB compression point of better than -0.8 dBm over a 7.5-GHz bandwidth.

A VHDL-AMS Simulation Environment for an UWB Impulse Radio Transceiver

Ultrawideband (UWB) communication based on the impulse radio paradigm is becoming increasingly popular. According to the IEEE 802.15 WPAN low rate alternative PHY Task Group 4a, UWB will play a major role in localization applications, due to the high time resolution of UWB signals which allow accurate indirect measurements of distance between transceivers. Key for the successful implementation of UWB transceivers is the level of integration that will be reached, for which a simulation environment that helps take appropriate design decisions is crucial. Owing to this motivation, in this paper we propose a multiresolution UWB simulation environment based on the VHDL-AMS hardware description language, along with a proper methodology which helps tackle the complexity of designing a mixed-signal UWB system-on-chip. We applied the methodology and used the simulation environment for the specification and design of an UWB transceiver based on the energy detection principle. As a by-product, simulation results show the effectiveness of UWB in the so-called ranging application, that is the accurate evaluation of the distance between a couple of transceivers using the two-way-ranging method.

CMOS wideband analogue delay stage

A new second-order all-pass filter with maximum achievable delay-bandwidth-product (DBW) is presented. The proposed circuit will be used as a wideband delay element in impulse radio ultra-wideband transceivers. Benefiting from a simple architecture, the proposed circuit achieves a 60 ps delay across a 10 GHz bandwidth, which is the largest delay ever reported over such a wide bandwidth. In addition, the most noticeable advantage of this delay circuit is the small variation of group delay across a wide frequency range, which means negligibly small phase distortion introduced by the circuit.

A Novel Multi-Antenna Impulse Radio UWB Transceiver for Broadband High-Throughput 4G WLANs

In the last years, a lot of attention has been devoted to both multi-antenna systems with space-time orthogonal block coding (STOBC) and ultra wideband (UWB) transceivers based on impulse-radio (IR) technologies. In this short contribution we anticipate the architecture of a novel transceiver merging both multi-antenna and pulse position modulation (PPM) IR-UWB techniques and then we test the performance in flat-faded application scenarios typical of emerging broadband 4G WLANs. Three main appealing features are retained by the sketched transceiver scheme. First, it allows to equip the UWB receiver with reliable estimates of the (possibly time-varying) underlying multiple-input multiple-output (MIMO) UWB without reducing the overall information throughput conveyed by the system. Second, the performance confirms that the proposed transceiver is able to achieve "full diversity" even at SNRs as low as 1.5-2 dB. As a consequence, the resulting BERs outperform those of current Single-Input Single-Output (SISO) IR-UWB transceivers over two orders of magnitude even at SNR's as low as 3-4 dB. Third, at target BER's below 10/sup -2/ and radiated powers around 250 μW, the coverage ranges allowed by the proposed MIMO IR-UWB scheme typically outperform those of conventional SISO IR-UWB ones of about two orders of magnitude.