Device Free Detection in Impulse Radio Ultrawide Bandwidth Systems (original) (raw)
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On the Variance-Based Detection for Impulse Radio UWB Systems
IEEE Transactions on Wireless Communications, 2016
A variance-detection (VD) based impulse radio ultra-wideband (IR-UWB) system has a potential of mitigating narrowband interference (NBI), even in multipath environments. However, as a highly nonlinear system which involves fourth-order multiplications, comprehensive analysis and evaluations of its performances have not been seen so far. In this paper, we address the issues by developing a log-normal random distribution model for the VD-based IR-UWB receiver and deriving the analytical bit-error-rate formulas for the system in both additive white Gaussian noise and CM1 multipath channels with and without NBIs for the first time. Furthermore, through both theoretical analysis and simulations, we show that the presented VD-based receivers can outperform the conventional energydetection based and the fourth-order detection based receivers and have a stronger inherent ability to mitigate destructive performance degradation caused by strong NBIs. This makes the VD-based IR-UWB system a good candidate as a non-coherent IR-UWB receiver for low power and low complexity applications.
Frequency domain detectors for different data-rate short-range UWB communications
IEEE International Symposium on Spread Spectrum Techniques and Applications, 2006
Low and high data-rate applications can be foreseen for future ultra-wideband systems which are based on impulse radio and proper detection schemes have to be designed for the most general scenarios. In this paper, we study the performance of a suitable communication scheme in two different short-range communication scenarios where a base station transmits low or high data-rate flows to several mobile terminals in an indoor environment characterized by severe multipath propagation. The proposed system relies on both the introduction of the cyclic prefix at the transmitter and the use of a frequency domain detector at the receiver. Two different detection strategies based either on the Zero Forcing (ZF) or on the Minimum Mean Square Error (MMSE) criteria have been investigated and compared with the classical RAKE. The results show that the proposed approach is well suited in indoor wireless environment where multipath propagation tends to increase the effects of the interference.
Frequency domain detectors in different short-range ultra-wideband communication scenarios
Eurasip Journal on Wireless Communications and Networking, 2006
We study the performance of an innovative communication scheme for ultra-wideband systems which are based on impulse radio in two different short-range communication scenarios: the proposed system relies on both the introduction of the cyclic prefix at the transmitter and the use of a frequency domain detector at the receiver. Two different detection strategies based either on the zero forcing (ZF) or on the minimum mean square error (MMSE) criteria have been investigated and compared with the classical RAKE, considering two scenarios where a base station transmits with a different data rate to several mobile terminals in an indoor environment characterized by severe multipath propagation. The results show that the MMSE receiver achieves a remarkable performance, especially in the case of highly loaded high data-rate systems. Hence, the proposed approach is well suited for high-throughput applications in indoor wireless environments where multipath propagation tends to increase the effects of the interference.
Low and high data-rate applications can be foreseen for future ultra-wideband systems which are based on impulse radio and proper detection schemes have to be designed for the most general scenarios. In this paper, an innovative frequency domain detection strategy is tested in two different indoor short-range communication scenarios where several mobile terminals transmit low or high data-rate flows to a base station. Both Zero Forcing (ZF) and Minimum Mean Square Error (MMSE) criteria have been investigated and compared with the classical RAKE. The results show that the proposed approach is well suited for the considered scenarios.
Frequency domain detectors for ultra-wideband communications in short-range systems
IEEE Transactions on Communications, 2000
In this paper, we propose an original multiuser detector for high rate short-range impulse radio ultra-wideband systems. The proposed receiver relies on both the introduction of the cyclic prefix at the transmitter and the use of a frequency domain multiuser detector at the receiver. Zero Forcing (ZF) and Minimum Mean Square Error (MMSE) detection strategies have been investigated and compared with the classical RAKE, considering a scenario where several mobile terminals transmits to a base station in an indoor environment characterized by severe multipath propagation. The results show that the MMSE receiver achieves the best performance, irrespective of the number of active terminals.
An Effective Selective Detection Scheme Based on Pulse Repetition for Noncoherent UWB Systems
IEEE Transactions on Circuits and Systems II: Express Briefs, 2008
We propose a selective detection scheme based on pulse repetition considering the bit-error rate (BER) performance and complexity of noncoherent ultra-wide-band (UWB) systems. To take system complexity into account, the proposed scheme transmits the UWB signals by simple pulse repetition at the transmitter, like conventional pulse repetition coding (PRC). However, to effectively improve the BER performance, the proposed scheme performs selective detection by estimating the signal-to-noise ratio of the received pulse-repeated signals at the UWB receiver. Hence, the proposed scheme effectively improves the BER performance of the noncoherent UWB systems without much increasing system complexity, as compared to the conventional PRC.
Detection of UWB signal using dirty template approach
Signal, Image and Video Processing, 2013
This paper handles the problem of detecting ultra-wideband signals in the presence of dense multipath channel and ambient noise. To design a low-complexity high-performance signal detection process, the dirty template approach is proposed. We first explain the dirty template technique and its implementation in UWB communication systems. Then, the Neyman-Pearson theorem is applied to derive the UWB signal detector and select the suitable detection threshold values. Finally, the performance of the proposed dirty template detector is evaluated in terms of the detection and false alarm probabilities for different threshold values, signal-to-noise ratio and number of dataaided symbols.
The 15th International Symposium on Wireless Personal Multimedia Communications, 2012
The paper investigates chirp pulse compression as a signal dimension reduction technique in non-coherent Impulse-Radio Ultra-Wideband (IR-UWB) communications. Two common types of non-coherent IR-UWB detection are considered, energy detection of IR-UWB Pulse Position Modulated (PPM) symbols and sample-wise differential detection of Differential Phase Shift Keying (DPSK) IR-UWB symbols, as well as a newly introduced sample-wise differential detection of IR-UWB PPM symbols. A common problem with these low-complexity IR-UWB detection schemes is poor performance when the dimension of the symbol in detection is high, which is usually the case at low data rates and is especially pronounced in interference environments. Chirp pulse compression mitigates this problem by reducing the dimension of the symbol in detection by using a very small fading factor, which also lowers the computational complexity in the case of digital implementation. In the analytic part of the paper, we develop a closed-form expression for the bandwidth and dimension of the signal after the chirp pulse compression, which was lacking before. Furthermore, a closed-form expression of the bit error probability in white noise with the above detection schemes is also given. In the numerical part of the paper, we compare the performance with and without chirp pulse compression of the above modulation/detection pairs in noise and interference environments.
Sample-wise differential detection of Impulse-Radio Ultra-Wideband Pulse Position modulated symbols
2012 6th International Symposium on Medical Information and Communication Technology (ISMICT), 2012
The paper describes technique for differential detection of Impulse Radio Ultra-Wideband (IR-UWB) Pulse Position Modulated (PPM) symbols. An expression for probability of error in noise is derived. The numerical results show the method's performance enhancement compared to the energy detection in noise and considerable performance enhancement in multiuser interference. The method is applicable to the mandatory mode of the IEEE 802.15.6 Body Area Network (BAN) IR-UWB standard.
Optimum multi-user detection in ultra-wideband (UWB) multiple-access communication systems
2003
This paper investigates multiuser detection in multiple-access communicaton systems based on ultrawideband (UWB) technology. As user numbers increase and the bandwidth to pulse repetition frequency (PRF) decreases, multiple-access interference (MAI) is expected to adversely affect system capacity and performance. The paper presents a framework for the design of multiuser detectors and proposes the optimum multiuser detector for UWB. Numerical examples illustrate the performance of the optimum detector versus that of the conventional single-user UWB detector. I. INTRODUCTION Ultra-wideband (UWB) or impulse radio for commercial communication applications is a recent innovation [1, 2, 3, 4]. UWB transmitters employ short carrierless pulses at low power with bandwidths of up to or more than several GHz [1, 2]. The technology has many advantages which stem from its ultra-wideband nature. It not only experiences significantly less fading margins as reported recently in [5, 6, 7]. It also offers extremely fine time-resolution and the possibility of achieving processing gains much larger than those of typical direct-sequence spread-spectrum communication systems [5]. In particular, the absence of a sinusoidal carrier obviates the need for radio frequency (RF) or intermediate frequency (IF) mixers. It is important to note the many challenges of UWB deployment [8, 4]. These include regulatory issues and, in particular, coexistence and interference-related issues with Global Positioning System (GPS) receivers. Potential applications include wireless local area networks (LAN), ranging devices and multiple-access communication systems for short-range or indoor applications [3]. This report considers the application of UWB technology to multiple-access communication systems. The idea of multiple-access communications using UWB (UWB-MA) appears to have been first proposed by Scholtz in [9] with subsequent analyses in [3, 10, 11]. Such systems are conceptually similar to asynchronous code-division multiple-access (CDMA) systems in certain aspects. The