Ultra-wideband Transmitter Research Articles

IEEE 802.15.6 WBAN Standard Compliant IR-UWB Time-Hopping PPM Transmitter using SRRC signaling pulse

This paper develops the design of an IEEE 802.15.6 Impulse-Radio (IR) Ultra-Wideband (UWB) transmitter for Wireless Body Area Networks (WBAN) in 180-nm CMOS technology. The transmitter operates at the mandatory data rate of 0.487 Mbps and employs a pulse position controller (PPC) to place the Square Root Raised Cosine (SRRC) pulse for a time-hopping pulse position modulation (TH-PPM) scheme. This transmitter features a novel piece-wise linear approximation (PWLA) approach for generation of SRRC signaling pulse. It is found that the generated PWLA SRRC pulse is fully compliant with the WBAN spectral mask. The proposed PWLA approach has the potential to approximate an arbitrary signaling waveform with a high degree of accuracy and hence should be useful in transceiver realizations.

Area and Power Efficient 3–8.8-GHz IR-UWB Transmitter With Spectrum Tunability

An ultralow-power and low-complexity impulse radio ultrawideband (IR-UWB) transmitter (TX) is fabricated in the low-cost 180-nm United Microelectronics Corporation (UMC) CMOS technology. The TX offers control of the power spectral density (PSD) by using a tunable pulse generator and a controllable switched oscillator. It supports on-off keying (OOK) coding and occupies a total die area of 0.35 mm2. The measured results show the transmitter output amplitude of 130 mVp-p with the pulse width of 1.0 ns, and the PSD with 10-dB bandwidth from 3 to 8.8 GHz. The total dc power consumption is 0.6 mW, corresponding to the energy consumption of 3 pJ/pulse at 200-MHz pulse repetition frequency.

Design of a Planar Transmission Line Balun Based on Novel Phase Inverter

In this paper, a planar ultrawideband (UWB) transmission line balun based on a novel phase inverter is proposed, which consists of three coaxial connector to double-sided parallel-strip line (DSPSL) transitions, a two-section Wilkinson divider, and a phase inverter. In the phase inverter, a 90-degree rotating transition is applied to realize field inversion. It maintains good structural uniformity of the two outputs of the balun and ensures the characteristics of equal energy division and a stable 180-degree phase difference in wide frequency band. Compared with other designs, the proposed balun has the advantages of easy to design, UWB operation, low reflection, equal power division and a stable phase difference. The presented balun works in the 0.52 GHz to 2.32 GHz band, covering 4.46 octaves. The measurements can achieve the reflection, amplitude imbalance and phase imbalance characteristics below -15 dB, ±0.46 dB and ±4 deg, respectively. The designs including the phase inverter and balun are fabricated and measured to verify the performance, and the measurements are found to be in good agreement with the simulations. In addition, the UWB potential of the proposed balun is studied. From an example based on a 1:2 balun, we can conclude that the proposed balun has the potential to work in a wider frequency band within the range of 0.1 GHz to 3GHz.

Modern ultra-wideband communications: recent overview and future prospects

Regarding the modulation schemes and multiple access techniques, modern ultra-wideband (UWB) communication displays unique features in wideband, high-speed data transmission, low-power consumption and high security comparing to other wireless communication systems. We present a general review of historical development, key features and typical applications on UWB, then briefly discuss its recent progress in IEEE standards, application potentials for broadband wireless access and current benefits. Future development on UWB transmission schemes and challenges of system design, are concisely proposed in contrast to those of several other typical communication systems.

EXPERIMENTAL INVESTIGATION OF UWB SIGNAL INTERFERENCE EFFECT BETWEEN UWB COMMUNICATION DEVICE AND VSAT

This paper presents the experimental investigation of the Ultra Wideband (UWB) signal interference effect between commercialized UWB communication device (UCD) and Very Small Aperture Terminal (VSAT). Recent research trend shows increase of interest to make use of UWB signal for Internet of Things (IoT) application. It is expected that IoT devices based on UWB technology increases in the future and can become unattended jammer to other services. The analysis involves two sets of experimental set up: i) UWB communication system is the interference victim from narrow band signal and other UWB transmission and ii) signal radiated from UCD devices using UWB signal interfere to other existing radio communication services which in this case a VSAT. The level of interference is evaluated based on the measured bit error rate (BER), round trip time (RTT) and carrier over noise ratio (C/N). The finding from this paper can be used as a guide for new interference mitigation techniques and spectrum planning purposes.

An all-digital frequency tunable IR-UWB transmitter with an approximate 15th derivative Gaussian pulse generator

This work presents a new frequency-tunable, OOK–modulated, impulse-radio ultra-wideband (IR-UWB) transmitter, where approximate 15th derivative Gaussian pulses are produced by a monopulse-synthesis pulse generator. The center frequency of our output UWB pulses can be easily adjusted between 4 and 9 GHz by controlling delay time. Thus, the whole UWB frequency band from 3.1 to 10.6 GHz can be covered and utilized. Since the proposed monopulse-synthesis pulse generator already includes a pulse shaping function, RF bandpass filters are not required, thus realizing the extremely low complexity and small circuit area. The proposed IR-UWB transmitter has been implemented and fabricated in a standard 0.18 μm CMOS 1p6m process. The power supply voltage is 1.8 V and the targeted data rate is 31.25 Mbps. Chip measurement results show that the power spectrum density conforms to the FCC spectrum masks, and the peak-to-peak voltage of output UWB pulses is 56 mV. In addition, the core area of the chip is 0.02 mm2, the measured frequency tuning range is 3.1–10.6 GHz, and the measured energy dissipation is only 12.5 pJ/bit. Compared to the state-of-the-art designs in the literature, the chip area and tunable frequency range are improved by at least 33% and 53%, respectively.

Ultra-wide Band Positioning in Sport: How the Relative Height Between the Transmitting and the Receiving Antenna Affects the System Performance

This work presents the performance evaluation of an ultra-wide band (UWB) positioning system for monitoring athletes in sports. Focusing on a five-a-side football scenario, the objective of this paper is to evaluate the performance of the proposed UWB positioning system by considering three different heights of the receiver antenna: 1 m, 1.6 m and 2 m. The system consists of four static UWB receivers placed at the corners of the pitch, while a player is equipped with an UWB transmitter worn on the upper back of the body. The UWB communication link from the on-body transmitter to the receivers can be influenced by the relative height between the transmitting and the receiving antenna. In order to assess the performance of the positioning system, on-field tests have been performed with five players. The players were asked to run at a variable speed while traveling a predefined path inside the pitch. Three metrics have been considered to assess the system performance: the accuracy of the position for each player, the percentage of packets lost by each receiver with respect to the total number of transmitted packets, and the percentage of packets respectively received by one, two, three, and four anchors, with respect to the total number of transmitted packets. The experimental results show that the intermediate height of 1.6 m for the receiver antenna presents the best results: the lowest value of position RMSE (equal to 31 cm), an average of 28% of the lost transmitted packets and an average of 63% of the transmitted packets being received at least by 3 anchors.

103 nm Ultra-Wideband Hybrid Raman/SOA Transmission Over 3 × 100 km SSMF

We report on the ultra-wideband (UWB) transmission of a 103 nm signal over 3 × 100 km of standard single mode fiber (SSMF), a widely-deployed fiber in terrestrial transmission networks. In such UWB systems, nonlinear effects such as stimulated Raman scattering (SRS) must be taken into account in the system design. We characterize the SRS impact in high power regime for this UWB spectrum. We study the evolution of SRS over the bandwidth when tilting the input spectrum to counter the inter-band power transition. We transmit 254 probabilistically constellation shaped (PCS)-64QAM channels over 300 km of SSMF and demonstrate a 107-Tb/s transmission throughput over a continuous 103 nm optical bandwidth using backward Raman pumping and SOA technology.

System-level study on impulse-radio integration-and-fire (IRIF) transceiver

Integrate-and-fire (IFN) model of a biological neuron is an amplitude-to-time conversion technique that encodes information in the time-spacing between action potentials (spikes). In principle, this encoding scheme can be used to modulate signals in an impulse radio ultra wide-band (IR-UWB) transmitter, making it suitable for low-power applications, such as in wireless sensor networks (WSN) and biomedical monitoring. This paper then proposes an architecture based on IFN encoding method applied to a UWB transceiver scenario, referred to herein as impulse-radio integrate-and-fire (IRIF) transceiver, followed by a system-level study to attest its effectiveness. The transmitter is composed of an integrate-and-fire modulator, a digital controller and memory block, followed by a UWB pulse generator and filter. At the receiver side, a low-noise amplifier, a squarer, a low-pass filter and a comparator form an energy-detection receiver. A processor reconstructs the original signal at the receiver, and the quality of the synthesized signal is then verified in terms of effective number of bits (ENOB). Finally, a link budget is performed.

An IR-UWB Transmitter using Pulse Injection

This work presents a new pulse-shaping technique for an impulse-radio ultra-wideband (IR-UWB) transmitter which is intended for RFID tags and wireless sensor applications. The proposed pulse is derived from a rectangular pulse with its side-band energy suppressed in order to satisfy the FCC UWB regulation, in particular at low frequency band (3.1 - 4.8 GHz). To verify its effectiveness, the new pulse generator was designed in a 180-µm CMOS process. The simulation results indicate that the spectrum of the transmitted pulse can be fitted within the FCC UWB spectral mask. The total circuit consumes 926 µW at a 10 MHz pulse repetitive frequency (PRF).

Study on the Impact of Nonlinearity and Noise on the Performance of High-Capacity Broadband Hybrid Raman-EDFA Amplified System

We experimentally demonstrated the transmission of 312 $\times {}$ 35 GBd DP-256QAM over 9 $\times {}$ 70 km spans using hybrid distributed Raman-EDFA (HRE) amplifiers with a continuous 91 nm gain bandwidth. A total throughput of 120 Tbit/s over 630 km is demonstrated, with a net achievable information rate after SD-FEC of 10.99 bit/symbol. An extensive, theoretical investigation of the noise contributions originating from amplifier, transceiver sub-system and fiber nonlinearity were carried out using the Gaussian noise model in the presence of inter-channel stimulated Raman scattering (ISRS GN model). The ISRS GN model accounts for arbitrary, wavelength dependent signal power profiles along fiber spans, which is vital for the modeling of ultra-wideband transmission, particularly for hybrid Raman-amplified links. The analysis serves to quantify the relative noise contributions and explain the performance achieved. It was found that, due to the low noise HRE amplifier and a transmission distance of 630 km, the noise originating from the transceiver sub-system imposed a penalty of 6 dB in SNR. For this system, the transceiver noise is, therefore, the main limitation to the system throughput.

A weighted least squares consideration for IR-UWB radar based device-free object positioning estimation for indoor environment

<p>Impulse Radio Ultra-Wideband (IR-UWB) radar is a type of radar functioning based on UWB transmission technology that uses an exceedingly wide bandwidth low power impulse signal to continuously transmitting and receiving the impulse signal for object detection within a range. To date, most of the proposed Ultra-Wideband (UWB) transmission technology based object positioning estimation systems for indoor environment depends on objects to be attached with an active UWB devices. In certain circumstances, it is ideal to track objects in passive manner without the requirement of any attached tracking devices or device-free object positioning estimation. IR-UWB radar has shown promising utilization in realizing device-free object positioning estimation for indoor environment. With this motivation, in this paper a work on weighted least squares consideration for IR-UWB radar based device-free object positioning estimation for indoor environment is presented.</p>

CNN‐based Tx–Rx distance estimation for UWB system localisation

In this Letter, the authors propose a novel convolutional neural network (CNN)-based estimation of the distance between an ultra-wideband (UWB) transmitter and receiver for a localisation. By exploiting the UWB signal characteristics, such as high-resolution in the time domain, the CNN is designed. The proposed CNN-based method estimates the distance from only the received signals, without signal-to-noise ratio information which is used for the conventional time of arrival (TOA)-based methods. Furthermore, as verified by simulation, the proposed CNN-based method significantly outperforms the conventional TOA-based method with respect to the distance estimation accuracy.

A Stochastic Channel Model for Ultra Wideband In-Body Communication.

For wireless capsule endoscopy, high quality images need to be transmitted from inside the digestive tract to an on-body receiver. Ultra wideband transmission offers the possibility to achieve much larger data rates than achievable with today's technology. To design such an ultra wideband transmission system a comprehensible channel model is needed for simulation of the propagation behavior through the human abdomen. In this paper we present a stochastic channel model, that includes the variation of the radio propagation depending on the location of a receive antenna on the body as well as on the physiological properties of different human body models.

Low‐power low‐data‐rate IR‐UWB transmitter for paediatric apnoea monitoring system

Wireless telemetry has recently become a very important feature for healthcare monitoring and wearable systems. Several factors such as reliability, power budget, and cost impose design constraints for data transmission. Literature reported transmitters characterised by lower energy efficiency for low data rate operations and are not quite suitable for low-power biomedical applications. To overcome these constraints, this paper presents an impulse radio ultra-wideband (IR-UWB) transmitter that implements a heavy duty-cycling approach to achieve low power consumption. The transmitter is designed to be used for a non-invasive wireless respiration monitoring and apnoea detection system for premature infants. The transmitter is designed and fabricated in 130 nm standard CMOS process achieving 9.12 µW of power consumption and 91.2 pJ per pulse at 100 kbps data rate.

An Energy Efficient Multi-User Asynchronous Wireless Transmitter for Biomedical Signal Acquisition.

The paper presents a novel transmitter architecture for short-range asynchronous wireless communication, applicable to simultaneous multi-user wireless acquisition of biological signals. The analog signal, provided from an analog biosensor, is transformed to time information using an Integral Pulse Frequency Modulator (IPFM) as a Time-Encoding Machine. The IPFM generates a time-encoded unipolar pulse train, maintaining the linear dependence of the output pulse distance on analog input voltage. The system enables continuous acquisition of the signals from multiple sensors in which each transmitter has unique feedback loop delay used for multi-user coding. IPFM pulses trigger the Impulse Radio Ultra-Wideband pulse generator directly, providing two ultra-wideband (UWB) pulses per each IPFM pulse. Due to the lack of internal clock signal and microprocessor-free multi-user coding, the circuitry satisfies the requirements of multi-user coding energy efficiency and size reduction, which are crucial demands in biomedical applications. The proposed Time-Encoded UWB (TE-UWB) transmitter is implemented in 0.18 [Formula: see text] CMOS technology. Measurement results of the IPFM transfer function for input voltage ranging from 0.15 to 1.5 V are presented, providing the dependence of the IPFM pulse time distance on analog input voltage and power consumption dependence on the input voltage level. For continuous monitoring operation, total power consumption of the transmitter circuitry for the maximum input voltage is 10.8 [Formula: see text], while for the lowest input voltage it increases to 40.48[Formula: see text]. The circuit occupies 0.14 [Formula: see text].

Quasi-Optic Transmitter and Receiver Modules Enabling Next-Generation Ultra-Broadband Wireless Links at Carrier-Wave Frequencies Ranging from 60 to 180 GHz

A wireless link using quasi-optic transmitter and receiver modules is demonstrated, enabling carrier wave frequency selection within various millimeter-wave bands from E-band to D-band without changing the modules. The photonics-based transmitter driven by an optical heterodyne source uses an ultra-wideband PIN photodiode transmitter module. The receiver is composed of zero-bias Schottky barrier diode envelope detector, with a minimum of – 30 dBm measured sensitivity leading to a calculated link distance of 15 m. Error-free data transmission also enables real-time HDTV streaming.

A Multiband, Spectrally-Efficient Impulse Radio Transmitter Design with Low-Complexity CMOS Pulse Generator for IEEE 802.15.4a Application

A novel multiband impulse radio ultra-wideband (MB-IR-UWB) transmitter with an energy-efficient and low-complexity pulse generator design technique compliant with the IEEE 802.15.4a standard is investigated in this paper. This transmitter is made up of a new differential narrow triangular pulse generator, a new multiband voltage-controlled oscillator (VCO), an active mixer and a variable-gain power amplifier (PA). It operates at 14 UWB bands and generates an output signal with the duration of 3[Formula: see text]ns, more than 500[Formula: see text]MHz of channel bandwidth and more than 20[Formula: see text]dB of sidelobe suppression, while achieving an average energy efficiency of 51.36 pJ/pulse from 1.4-V supply. Improving spectral flexibility and worldwide compliance is the major contribution brought by this paper to make this circuit as a multifunction wireless device well suited for low-cost, low-power multiband applications.

A Closed-Form Approximation of the Gaussian Noise Model in the Presence of Inter-Channel Stimulated Raman Scattering

An accurate, closed-form expression evaluating the nonlinear interference (NLI) power in coherent optical transmission systems in the presence of inter-channel stimulated Raman scattering (ISRS) is derived. The analytical result enables a rapid estimate of the signal-to-noise ratio (SNR) and avoids the need for integral evaluations and split-step simulations. The formula also provides new insight into the underlying parameter dependence of ISRS on the NLI. The proposed result is applicable for dispersion unmanaged, ultra-wideband transmission systems that use optical bandwidths of up to 15 THz. The accuracy of the closed-form expression is compared to numerical integration of the ISRS Gaussian Noise model and split-step simulations in a point-to-point transmission, as well as in a mesh optical network scenario.

Ultra-Wideband WDM Transmission in S-, C-, and L-Bands Using Signal Power Optimization Scheme

Ultra-wideband (UWB) wavelength division multiplexed (WDM) transmission using high-order modulation formats is one of the key techniques to expand the transmission capacity per optical fiber. For UWB systems, the nonlinear interaction caused by inter-band stimulated Raman scattering (SRS) must be considered. Therefore, we have proposed and demonstrated a scheme to optimize the fiber input powers for UWB transmission systems considering the signal power transition caused by the inter-band SRS. We demonstrated a single-mode capacity of 150.3 Tb/s using the proposed power optimization scheme with 13.6-THz UWB in the S-, C-, and L-bands over 40-km transmission. Spectral efficiency of 11.05 b/s/Hz was achieved with 272-channel 50-GHz spaced WDM signals of 45-GBaud polarization division multiplexed 128 quadrature amplitude modulation.