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Cooperative communication, which utilizes neighboring nodes to relay the overhearing information, has been employed as an effective technique to deal with the channel fading and to improve the network performances. And network coding, which combines several packets together for transmission, is very helpful to reduce the redundancy at the network and to increase the overall throughput. Introducing...
This paper presents the analysis on communication range and interference range of the IEEE 802.15.4g Smart Utility Networks (SUN). Firstly, error performance analysis corresponding to different propagation environments based on realistic measurement is conducted. Secondly, the effective communication range of SUN devices in these propagation channels are presented and discussed. Thirdly, in the presence...
In this paper we introduce an efficient decoding method which is based on the dimensionality reduction of the search tree in the sphere decoder for the golden code in a low SNR regime. A codeword of the golden code has four independent m-QAM data symbols, hence, the required complexity of the exhaustive-search decoder is m4. An efficient implementation of the maximum-likelihood decoder for the golden...
This paper presents a study of the Dedicated Short Range Communication (DSRC) Physical Layer in order to determine its reliability for Vehicle-2-Vehicle (V2V) communication under varying Signal-to-Noise Ratio (SNR), vehicle speed, delay spread, and packet lengths. In particular, we focus on computing the expected delay when packets with errors are retransmitted until received correctly. IEEE 802.11a...
It is clearly that mobile ad-hoc networks (MANET) gained the interest of research and market place lastly, and that is due to its wide variety of applications. However, nodes mobility implies rapid topology changes, where a channel aware routing protocol is becoming a necessity to cope with this problem. Many channel aware routing metrics are proposed in the literature, however these routing metrics...
In this paper, the problem of informed-transmitter cooperative MIMO communications is addressed. The informed-transmitter link assumes that the distributed transmit nodes have access to channel state information. The channel state information includes the channel between the transmit and receive antenna arrays and a statistical model for interference impinging upon the receive array. In principle,...
This paper examines the effect of sensor performance on speaker diarisation in meetings and investigates the use of more advanced beamforming techniques, beyond the typically employed delay-sum beamformer, for mitigating the effects of poorer sensor performance. We present superdirective beamforming and investigate how different time difference of arrival (TDOA) smoothing and beamforming techniques...
In this paper, we propose an algorithm for timing synchronization that attains fundamental bounds derived by Weiss and Weinstein. These bounds state that, in addition to improving with time-bandwidth product and signal-to-noise ratio (SNR), timing accuracy also improves as the carrier frequency gets larger, if the SNR is above a threshold. Our algorithm essentially follows the logic of the Weiss-Weinstein...
Although most of the conventional localization algorithms rely on Line of Sight (LOS) conditions, fingerprinting allows positioning in multipath and even in Non-LOS (NLOS) environments. In contrast to the traditional Received Signal Strength (RSS), the Power Delay Profile (PDP) fingerprint may allow positioning on the basis of a single link if the multipath is rich enough. Fingerprinting is a pattern...
In this paper, we present a method of detecting the range and Doppler phase of a point target using multiple antennas. As a key illustrative example, we consider a 4 × 4 system employing a unitary matrix waveform set, e.g., formed from Golay complementary sequences. When a non-negligible Doppler shift is induced by the target motion, the waveform matrix formed from the complementary sequences is no...
This paper proposes a frame loss concealment technique for audio signals, which is designed to overcome the main challenge due to the polyphonic nature of most music signals and is inspired by our recent research on compression of such signals. The underlying idea is to employ a cascade of long term prediction filters (tailored to the periodic components) to circumvent the pitfalls of naive waveform...
The feasibility of compressed sensing (CS) based waveform-reconstruction for data sampled from random equivalent sampling (RES) method is investigated. A novel measurement matrix motivated by the Whittaker-Shannon interpolation formula is proposed for this purpose. Experiments indicate that, for spectrally-sparse signal, the CS reconstructed waveform exhibits significantly higher signal-to-noise ratio...
In contrast to other well-known techniques for spectral analysis such as the discrete Fourier transform or the wavelet transform the constant-Q transform (CQT) matches the center frequencies of its sub-band filters to the frequency scale of western music and accounts for the requirement of frequency-dependent bandwidths. However, it does not possess a strict mathematical inverse. Therefore, we derive...
Time delay as well as error accumulation makes transmission of high-quality streaming media over multi-hop wireless networks more challenging. Since conventional TCP/IP-based protocol drops and retransmits the whole packet once error(s) occur above Physical Layer, which leads to long time delay and low efficiency in transmission, a new protocol for real-time streaming media transmission is proposed...
In this paper, we propose several channel allocation schemes via the Game theoretical approaches for the distributed CR networks. Distinguished from the literature, more important factors are taken into account when designing the potential games for the interweave and underlay CR networks, i.e. the queueing delay, complete inter-system interference and protection of primary users (PUs). Particularly,...
The performance limitation analysis of single-input-single-output (SISO) networked control systems (NCSs) over signal-to-noise ratio (SNR) constrained channel is proposed in this paper. The performance index is measured by the energy of the error variance response between the output of the plant and the reference signal. The performance limitation is obtained by applying H2 square error criterion...
This paper addresses the power assignment problem in multicarrier code-division multiple-access (MC-CDMA) systems. The problem is formulated as finding the correct transmission power to achieve a desired quality of service (QoS), described by an objective signal-to-interference and noise ratio (SINR). First, the model of the MC-CDMA is described, and by considering a matched filter at the receiver,...
A modified superscalar parallelization based phase-locked loop combined with the maximum-likelihood algorithm is proposed. Its high tolerance to laser linewidth is demonstrated both numerically and experimentally.
This paper presents the modeling and design consideration of a time-based ADC architecture that uses VCOs in a high-linearity, 2nd-order noise-shaping delta-sigma ADC. Instead of driving the VCO by a continuous analog signal, which suffers from the nonlinearity problem of the VCO gain, the VCO is driven in an intrinsically linear way, by a time-domain PWM signal. The two discrete levels of the PWM...
Medium Access Control (MAC) scheduler entity forms one of the most important parts of any high speed packet access system like HSDPA or LTE. To the best of our knowledge the LTE MAC schedulers that had been proposed so far constitute of sub-carrier resource scheduling mostly based on single criteria like user throughput, link conditions, buffer constraints or power requirement. The above LTE MAC scheduler...
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