Fig 6 - uploaded by A.s. Dmitriev
Content may be subject to copyright.
Source publication
A flexible chaotic ultra-wideband (UWB) communication system with an adjustable channel spectrum is proposed. Since the chaotic UWB bandwidth (BW) is independent of the data rate, the system band plan can be flexibly organized for various communication environments. The proposed system can overcome the spectral inefficiency and RF power wastage tha...
Context in source publication
Context 1
... of the VCO output is adjusted by controlling the dc offset of the input signal. Since the output frequency of the VCO is determined by the input voltage level, the input signal with dc offset can induce an oscillating frequency shift. During the signal up-conversion at the VCO, amplitude variation is converted to frequency-phase variation. Fig. 6 depicts a mea- sured chaotic signal waveform of the proposed chaotic signal generator at the center frequency of 4 GHz. The chaotic signal exhibits a nonperiodic continuous noise-like waveform in the time ...
Similar publications
During the next years, the number of wireless sensor and communication systems used in cars will increase significantly. The operational frequencies will span from the LF to the MMW range. In particular, Ultra-Wideband (UWB) systems will be introduced, due to the expected low costs of these systems and their technical advantages. This contribution...
Abstract— This paper reviews of high efficiency CMOS class-E power amplifier (PA) in gigahertz (GHz) frequencies range for wireless applications. The study is focused on the challenges in designing class-E PA especially in GHz frequencies range. Problems and limitations in high efficiency class-E PA and the circuits’ topologies are reviewed. Severa...
This paper reviews of single-ended high efficiency CMOS class-E power amplifier (PA) for wireless applications. The study is focused on the challenges in designing class-E PA especially in GHz frequencies range. Problems and limitations in high efficiency class-E PA and the circuits’ topologies are reviewed. Several works on CMOS class-E PA from ye...
This paper represents the design of a low-cost programmable CMOS voltage-to-frequency converter suitable for wireless sensor nodes signal conditioning. Designed in a 0.18μm CMOS technology supplied at 1.8V, it operates for a 0.0-1.6V input voltage with power consumption below 0.41mW. Three different output frequency ranges can be digitally selected...
This paper presents an implementation of an integrated Ultra-wideband (UWB), Binary-Phase Shift Keying (BPSK) Gaussian modulated pulse generator. VCO, multiplier and passive Gaussian filter are the key components. The VCO provides the carrier frequency of 4.1 GHz, the LC Gaussian filter is responsible for the pulse shaping in the baseband. Multiply...
Citations
... In this section, we carry out numerical simulation of the proposed system for different value pairs of the spreading factor β and the number of subcarriers M , i.e., [M, β] = [2,192], [4,96], [8,48], [16,24] being a constant. It means that for a fixed value of α, the system performance is compared in the cases having the same product of the total bandwidth B Σ and bit period T b . ...
... It can be seen that the RSS-MC-DCSK system performs better when M increases and β reduces in the same time. For example at E b /N 0 = 16dB, the BERs for [M, β] = [2,192], [4,96], [8,48], [16,24] in the cases of L = 2 and L = 3 are corresponding to 4.14 · 10 −2 , 1.97 · 10 −2 , 1.12 · 10 −2 , 7.81 · 10 −3 and 2.75 · 10 −2 , 1.08 · 10 −2 , 5.58 · 10 −3 , 4.01 · 10 −3 . ...
This paper proposes a multi-carrier differential chaos-shift keying (MC-DCSK) system using repeated spreading sequence (RSS), namely RSS-MC-DCSK, for chaos-based wireless communications. In the proposed system, instead of transmitting the chaotic spreading sequence on a predefined subcarrier as in conventional MC-DCSK, a DCSK-modulated signal, of which each two-bit duration consisting of reference and data-bearing sequences is sent via this subcarrier. Meanwhile, a repeated spreading sequence is produced by copying the reference sequence of the DCSK-modulated signal to the same and next bit periods. The parallel bit streams are multiplied with this RSS and the resulting signals are then conveyed by corresponding subcarriers. In the receiver, the signal retrieved from the predefined subcarrier is DCSK-demodulated and simultaneously used to recover the repeated spreading sequence. The correlative demodulation is performed for all the signals retrieved from the remaining subcarriers to decode the data. The structure and operation of the proposed system are described. BER performance under a multipath Rayleigh fading channel is theoretically analyzed and then verified by numerical simulations. In addition, the BER performance, energy and spectral efficiencies of RSS-MC-DCSK are evaluated in comparison to those of MC-DCSK.
... The two sequences are correlated at the receiver and the data bit is recovered based on the sign of the correlation value. For the goal of improving communication characteristics, e.g., bit rate, bit error rate, energy or spectral efficiency, and confidentiality in wireless environments, DCSK-based systems have been recently developed, which are based on the combination of DCSK and the other existing wireless techniques, such as Frequency-division multiplexing (FDM), Orthogonal FDM (OFDM), Multiple-input and multiple-output (MIMO), Ultra-wideband, cooperative and cognitive radio, and so on [14][15][16][17][18]. Actually, FDM and OFDM are two basic techniques of multi-carrier modulation (MCM) [19,20]. ...
This paper presents the design of a multi-carrier correlation delay-shift keying (MC-CDSK) system for the operation in wireless environments. In the proposed system, the sum of a chaotic sequence and it delayed version is considered to be a reference sequence and transmitted through a predefined subcarrier. The input data is divided into multiple pairs of bit sub-sequences, where the first and second ones of each pair are spread in the frequency domain by directly multiplying with the chaotic sequence and the delayed version, respectively. The sum of two resulting signals for each pair is then transmitted on a corresponding subcarrier. In the receiving side, the reference sequence retrieved from the predefined subcarrier and the signal retrieved from each of the remaining subcarriers are correlated with the delayed version of the other ones to recover the corresponding bit sub-sequence pair. The recovered pairs are combined to an output data. Schemes for the transmitter and receiver are designed and their operation over a multipath Rayleigh fading channel is described. The system performance is evaluated via theoretical analysis and then verified by numerical simulation. Our findings show that MC-CDSK system can improve communication features, i.e., bit error rate (BER) performance, energy and spectrum efficiency compared to those of the conventional CDSK.
... To overcome these problems, many solutions were proposed and discussed [156], [157], [159]. It was shown in [158] that the estimation problem reduces as an inverse of the product of bandwidth and bit duration. ...
... In [159], a flexible chaotic ultra-wideband (UWB) communication system with an adjustable channel spectrum is proposed to perform in various communication environments. The proposed system can overcome the spectral inefficiency and RF power wastage that is typically observed in conventional methods like the COOK system by utilizing adjustable channel allocations. ...
... On the other hand, the implementation and the proof-of-concept of non-coherent communication systems received more attention because of the chaotic synchronization-free procedures at the receiver side. In [159], a flexible COOK ultra-wideband (UWB) communication system with an adjustable channel spectrum is proposed to perform in various communication environments. The transceiver design that is implemented in CMOS 0.18 µm technology and includes adjustable chaotic signal generation and adaptive detection is shown in Fig 14. ...
Since the early 1990s, a large number of chaos-based communication systems have been proposed exploiting the properties of chaotic waveforms. The motivation lies in the significant advantages provided by this class of non-linear signals. For this aim, many communication schemes and applications have been specially designed for chaos-based communication systems where energy, data rate, and synchronization awareness are considered in most designs. Recently, the major focus, however, has been given to the non-coherent chaos-based systems to benefit from the advantages of chaotic signals and non coherent detection and to avoid the use of chaotic synchronization, which suffers from weak performance in the presence of additive noise. This paper presents a comprehensive survey of the entire wireless radio frequency chaos-based communication systems. First, it outlines the challenges of chaos implementations and synchronization methods, followed by comprehensive literature review and analysis of chaos-based coherent techniques and their applications. In the second part of the survey, we offer a taxonomy of the current literature by focusing on non-coherent detection methods. For each modulation class, this paper categorizes different transmission techniques by elaborating on its modulation, receiver type, data rate, complexity, energy efficiency, multiple access scheme, and performance. In addition, this survey reports on the analysis of tradeoff between different chaos-based communication systems. Finally, several concluding remarks are discussed.
... Recently, there has been research focus on chaotic signals due to their advantageous characteristics that can be used in the field of wireless communications [10][11][12][13][14][15][16][17][18][19]. This is principally associated with the inherent wideband characteristics of these signals, which make them well suited for spread-spectrum modulation systems [11,20,21]. ...
In this paper we design network coding schemes for Differential Chaos Shift
Keying (DCSK) modulation. In this work, non-coherent chaos-based communication
system is used due to its simplicity and robustness to multipath propagation
effects, while dispensing with any channel state information knowledge at the
receiver. We propose a relay network using network coding and DCSK, where we
first present a Physical layer Network Coding (PNC) scheme with two users,
$\mathcal{A}$ and $\mathcal{B}$, sharing the same spreading code and bandwidth,
while synchronously transmitting their signals to the relay node $\mathcal{R}$.
We show that the main drawback of this design in multipath channels is the high
level of interference in the resultant signal, which severely degrades the
system performance. Hence, in order to address this problem, we propose two
coding schemes, which separate the users' signals in the frequency or the time
domains. We show also in this paper that the performance of the Analog Network
Coding (ANC) with DCSK modulation suffers from the same interference problem as
the PNC scheme. We present the analytical bit error rate performance for
multipath Rayleigh fading channel for the different scenarios and we analyse
these schemes in terms of complexity, throughput and link spectral efficiency.
... The UWB noise radar for through-wall surveillance [3] or netted radar sensor system [4] has been proposed and demonstrated recently. In practice applications, the chaotic circuits are usually adopted to provide the UWB noise signal in the UWB noise radar [5][6][7]. In order to improve the performance of the UWB noise radar, the noise signal with higher bandwidth generated by photonics-assisted techniques was proposed [8][9][10][11][12][13][14][15]. ...
... In order to avoid the interference to the Global Position System (GPS) and the traditional mobile communication systems [20], the Federal Communications Commission (FCC) already stipulated that the UWB signals only work in the range of 3.1-10. 6 GHz, yet some other NB systems whose operated frequency bands locate in this range could not be immune to the interference totally [21]. The implicated NB communication systems include but not limited to the Wireless Fidelity (Wi-Fi) system operating at 5.2 GHz and the C-band satellite communication systems working at 7-8 GHz. ...
A fiber-distributed Ultra-wideband (UWB) noise radar was achieved, which consists of a chaotic UWB noise source based on optoelectronic oscillator (OEO), a fiber-distributed transmission link, a colorless base station (BS), and a cross-correlation processing module. Due to a polarization modulation based microwave photonic filter and an electrical UWB pass-band filter embedded in the feedback loop of the OEO, the power spectrum of chaotic UWB signal could be shaped and notch-filtered to avoid the spectrum-overlay-induced interference to the narrow band signals. Meanwhile, the wavelength-reusing could be implemented in the BS by means of the distributed polarization modulation-to-intensity modulation conversion. The experimental comparison for range finding was carried out as the chaotic UWB signal was notch-filtered at 5.2 GHz and 7.8 GHz or not. Measured results indicate that space resolution with cm-level could be realized after 3-km fiber transmission thanks to the excellent self-correlation property of the UWB noise signal provided by the OEO. The performance deterioration of the radar raised by the energy loss of the notch-filtered noise signal was negligible.
... A chaotic UWB communication system has several advantages such as high spectral efficiency, convenient power control, free cochannel interference, etc., which is considered to be an optional system in the IEEE 802.15.4a standard [27,28]. The chaotic signals are wideband, nonperiodic, and random-like signals, which offer a great many of attractive features. ...
... The decision levels of a comparator are determined by calculating the power distribution of received signals. This demodulation principle is as same as the one of noncoherent chaotic-on-off-keying demodulation scheme [27,28]. ...
... Their gain value is set to G = exp (˛L) in order to compensate for the fiber loss in an amplification period (L is the fiber length). For the chaotic UWB wireless channel, in Ref. [27][28][29], the authors all adopted the additive white Gaussian noise channel and various IEEE 802.15.4a multipath channel models, and mainly considered the additive white Gaussian noise and the multipath effects. Generally, the chaotic UWB wireless system experiences little degradation under the multipath environments. ...
A chaotic ultra-wideband (UWB) over fiber link is proposed and numerically demonstrated. The UWBsignals with steerable and flatted power spectrum are generated in the optical domain based on thechaotic dynamics of an optically injected semiconductor laser with optical feedback. The 2.5 Gb/s on-off keying encoded chaotic UWB signals are error-free transmitted through a 25 km signal-mode (SMF)while the signal to noise ratio (SNR) of the wireless channel was fixed on 20 dB. Without utilizing anydispersion compensation module, the RF spectral of the chaotic UWB signals received by antenna fullycomply with the spectral mask specified by the U.S. Federal Communications Commission (FCC), and theeye opening penalty (EOP) of the demodulated message are smaller than 3 dB. Moreover, we investigatethe dependency of the decoded data EOP on the data bit rate, the fiber transmission distance, and SNR ofthe wireless channel.
... Chaos phenomena with noise like behavior, aperiodic characteristic and significant variation for small initial condition fluctuations are existed widely in nature and can be generated by determined non-linear dynamic systems such as chaotic maps in engineering [7] . Chaos has been originally developed in control and safe communications [8,9] . In recent years, the results of researches on chaos have been successfully applied to radar systems. ...
Chaos shows many advantages in radar application. A chaos sampled method is proposed in this paper. Two sampling models are provided. We obtain new chaotic series of noise like phase space structures and sharp autocorrelation functions. The model of chaos-based frequency modulated waveform is then put forward and properties including frequency spectrum, ambiguity function are theoretically analyzed in detail. Additionally, a sufficient condition of chaotic behavior sustaining for this frequency modulation is deduced. We confirm that the sampling method can present much superiority in finding suitable or even perfect chaotic series for frequency modulated radar waveform design, and outstanding performance can be obtained as well when the sufficient condition is satisfied. Numerical simulations mainly based on the Bernoulli chaos validate the theoretical analysis.
... Because the recent RFID is used in various ways in collaboration with mobile communication networks, it needs to be of low cost, low power, and large data capacity. The near field communication (NFC) and the chipless RFID become the promising technology candidates for next generation ID systems [1][2][3]. ...
A new flexible microwave tag system using a frequency-scanning type RFID is proposed with multiple resonators based on defected ground structures (DGSs). The proposed system achieves fully passive tag systems using multiple resonators with a spiral-shaped DGS over a wide frequency range. The resonator implemented on the rear side of a transmission line has the advantages of excellent band notch characteristics as well as bit-error avoidance from the frequency selective reflection. In addition, the tag system is designed on a thin flexible substrate in order to be applicable for amorphous surfaces. The proposed microwave tags have been implemented with wideband antennas at 3–7 GHz on thick and thin flexible substrates. The flexibility of the thin substrate has been evaluated in terms of cognitive capability for various radiuses of curvatures. From the experimental results in an anechoic chamber, the excellent recognition of various multibits identification codes in a wireless transmission environment has been verified.
... Chaos phenomena with properties of pseudorandom behaviour, aperiodic characteristic and significant varying for small initial condition fluctuation are widely existed in nature and can be generated by determined non-linear dynamic systems such as chaotic maps in engineering [1]. The application of chaos is originally developed in control and safe communication systems [2,3]. In recent years, the results of researches on chaos have been successfully applied to radar systems. ...
Chaotic signals show many advantages in the application of radar systems. The technique described in this study focuses on the chaotic behaviour of the chaotic-based frequency- and phase-modulated signals. Chaotic-based frequency- and phase-modulated signals are introduced and analysed. Theoretical analysis points out that the initial chaotic map's phase structure is destroyed by frequency or phase modulation, which may be the direct reason that induces uncertain chaotic behaviours of the modulated signals based on chaos. Furthermore, a sufficient condition for chaotic maps to ensure the chaotic-based frequency-modulated signals remaining chaotic is discussed, and an initial sensitive correlation function for the chaotic-based phase-modulated signals is defined to estimate the possibility of chaotic behaviours remaining. Both theoretical analysis and computer simulation present the uncertain property of chaotic behaviours for chaotic-based signals, which induces better or worse signal performances depending on different chaotic maps and different signal modulation. It is also demonstrated that chaotic behaviours of the modulated signals based on chaos do not certainly provide satisfying performances for radar applications.
... As one type of wideband carriers, chaotic signals can be generated by simple circuits in any frequency band and at arbitrary power level [3]- [6]. Mapping digital information to chaotic signals, one can implement spread spectrum (SS) systems since the bandwidth of a transmitted chaotic signal is much larger than the data rate. ...
... ) is compressed as shown in (9). Clearly, the unit delay amount in the transmitter is changed to as in (10), whereas it was in the original version as in (6). As seen in Fig. 4, the delay implementation of the chaotic pulse cluster signals is performed by a group of delay lines, whose unit delay is . ...
Recently, an ultra-wideband (UWB) system with frequency-modulated differential chaos shift keying (FM-DCSK) modulation has attracted increasing interest for its many distinc- tive superiorities over its conventional counterparts, especially in low-rate and low-power wireless personal area network (WPAN) applications. However, some of its drawbacks, such as low en- ergy efficiency, complex implementation and weak multiaccess capacity, have also been noticed, which restrict its further ac- ceptance and applications. To overcome these problems, an architecture, named single-input and multiple-output (SIMO) FM-DCSK UWB system, is introduced in this paper. With chaotic transmitted signals based on a high-order Walsh function and multiple antennas diversity reception, this paper demonstrates the superiorities of the new system in bit error rate (BER) per- formance as well as in moderation complexity. Furthermore, by transmitting chaotic pulse cluster signals, an improved emission signal structure of the SIMO FM-DCSK UWB system is proposed so as to overcome the delay line implementation constraints and to further enhance the BER performance. Based on this new signal format, a method of combining time division and Walsh function division is introduced into the existing Walsh function division scheme, thereby resolving the inherent obstacle in user capability which was known to be limited by the order of the Walsh function. Index Terms—Chaotic pulse cluster, frequency-modulated differential chaos shift keying (FM-DCSK), single-input mul- tiple-output (SIMO), ultra-wideband (UWB).
