The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Ultra Wide Band (UWB) is foreseen to support a physical layer in Body Area Networks (BAN). The nature of the channel leads to the spread of the signal energy through the numerous paths from the reflexions in the environment. With such a multipath channel, inter-pulses interference (IPI) may occur if the channel delay spread is longer than the interval between two consecutive pulses. An energy detector...
This paper addresses the robustness of FM-UWB BAN radio to frequency-selective multipath and interference. Examples of the FM-UWB radio performance with IEEE802.15.6 BAN channel models are given. Robustness to interference is demonstrated and interference mitigation solutions at the physical layer of the receiver front-end are presented and illustrated with simulation results.
In this paper a new time domain approach which combines time reversal (TR) and downlink spatial beamforming (BF) is proposed that can result in WB/UWB Interference Mitigation (IM). In order to design the TR filter and the desired beams, the Channel State Information (CSI) between the UWB system and the other wideband (WB) victim users is required. This information is obtained using a hybrid Electromagnetic...
In this work, we propose an interference mitigation technique for ultrawide band (UWB)-impulse radio (IR) systems in the context of cognitive radio (CR). Such technique is based on the design of proper spreading sequences that introduce notch frequencies in both transmitted spectrum and matched filter (MF) receiver. In particular, binary, quaternary and polyphase direct sequence (DS) codes are proposed...
In this paper, a blind method to detect and suppress narrow-band interference (NBI) for multi-band orthogonal frequency-division multiplexing (MB-OFDM) based ultrawideband (UWB) communications is proposed. The method utilizes mean-square-error (MSE) statistics in the frequency domain to detect subcarriers damaged by NBI. Approximating the MSE statistics by a decision-feedback (DF) scheme creates a...
A novel linear blind reduced-rank scheme based on the constrained constant modulus (CCM) design criterion is proposed for interference suppression in direct-sequence ultra-wideband (DS-UWB) systems. The proposed two-stage blind receiver consists of a projection matrix that performs dimensionality reduction and is followed by a reduced-rank filter that produces the output. The projection matrix and...
A novel Narrowband Interference (NBI) suppression scheme using a Soft Limiter (SLM) is proposed for a digital noncoherent receiver in Time-Hopping Pulse Position Modulation Ultra Wideband (TH-PPM-UWB) communications. The NBI suppression is carried out in the analog domain (before the digital processing) via a feedforward structure. The suitability of this NBI suppression concept is confirmed by the...
An ultra-wideband (UWB) system has a frequency bandwidth that overlaps with spectra of many existing narrowband radio systems. As a result, impact of narrowband interference (NBI) becomes a key issue in the development of UWB systems. In this paper, under the IEEE802.15.4a industrial line-of-sight (LOS) channel model, the effects of NBI on the performance of the recently proposed differential code-shifted...
New channel estimation technique is proposed for multiband orthogonal frequency division multiplexing (MB-OFDM) ultra-wideband (UWB) systems. Several steps have been carried out to achieve this purpose. In first step, refined least square (LS) channel estimation is found out by using subspace-based narrowband interference (NBI) estimation method with prilimonary LS channel. In second step, low rank...
Electromagnetic interference can disrupt mobile satellite communications in both military and commercial mobile applications. Not only is this true when a high-power terrestrial source is in close proximity to a mobile satellite receiver, but it can be especially problematic when the vehicle or nearby vehicle has its own onboard interference source that overpowers the desired satellite signal. This...
A sub-band based ultra wideband (SUWB) system is proposed for energy efficient short range wireless communications. The proposed technique divides the bandwidth of 500 MHz into number of sub-bands that may be utilized for higher data rate or higher reliability or multi user access depending on system requirements. The energy efficiency is achieved by reducing the sampling rate requirements and also...
Since the coherent receivers are not feasible to implement low-cost ultra-wideband (UWB) impulse radio (IR) devices featuring extremely low power consumption, energy detector-based (ED-based) noncoherent receivers are more and more frequently chosen. The Pulse Polarity Modulation (PPM) scheme with a threshold compensated receiver is a promising candidate for the implementation of cheap and robust...
Synchronization is a crucial task and big challenge for ultra-wideband (UWB) systems, especially in the presence of inter-symbol interference(ISI) and inter-frame interference (IFI). This paper proposes a blind synchronization and demodulation algorithm that is capable of mitigating ISI and IFI for noncoherent UWB system. Employing a series of codeword matching and averaging operations, the proposal...
We propose a b-bit non-coherent receiver based on a Digital Code Matched Filter (DCMF) for a low data rate Time- Hopping Pulse Position Modulation Ultra Wide Band (TH-PPMUWB) system. The DCMF follows after a high-speed but lowresolution (b-bit, 1 ≤ b ≤ 4) Analog-to-Digital Convertor (ADC) and is employed before the non-coherent detection. It is matched to the user-specific sequence and restricts the...
A sub-band based ultra wideband (SUWB) system is proposed. The technique provides scope for using the ultra wideband bandwidth efficiently by exploiting the available link margin for short range communications. The bandwidth of 500 MHz or more is divided into a fixed number of sub-bands. The data transmission scheme over multiple sub-bands can be designed to achieve higher data rate, higher reliability...
Mitigating inter-symbol interference (ISI) in impulse radio is one of the challenges in achieving the high data rate potential of Ultra Wideband (UWB). Available techniques such as the use of Multiband OFDM and equalizer provide a good solution but they require complex implementation. This letter investigates and expands a newly proposed ISI reduction technique proposed in named "shift window"...
In this paper, we consider blind interference suppression in IR UWB communication system, and the means of a statistical technique called independent component analysis (ICA), taken as a solution for the coexistence of impulse-radio Ultra-wideband (IR-UWB) systems with other wireless systems was studied. Particularly for the evaluation of the system performance, tone, multiton, and partial-band interference...
Pulse position modulation (PPM) is a popularly adopted modulation scheme in the impulse radio based ultra wideband (UWB) systems. In order to shape the spectrum of the signal, a time dither on generated pulses leading to so-called Time Hopping UWB (TH-UWB) is introduced. Although of many advantages, the TH-PPM scheme faces serious challenges which are the cross modulation interference (CMI) and the...
SC-FDE (single-carrier with frequency-domain equalization) together with soft packet combining ARQ techniques (automatic repeat request) was shown to be effective for broadband wireless systems with deep fading effects such as those inherent to shadowing. However, they are not suitable to cope with strong interference effects, especially when the channel remains fixed. In this paper, we consider UWB...
In this paper, we present a new method to generate ultra-wide band (UWB) pulses that not only meet the power spectral constraint of Federal Communications Commission (FCC), but also easily mitigate the multiple narrow-band interferences (NBI) distributed in the UWB band, which is allocated from 3.1 GHz to 10.6 GHz. Especially, this method can be flexibly extended to suppress any wide-band interference...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.