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Full-duplex relays will play a key role in future networks since they increase the system diversity, coverage, and throughput; ideally doubling the spectral efficiency. However, the full duplex operation produces coupling between the transmitter and receiver front ends that drastically reduces the relay performance and it can even turn it unstable. Then, to allow a full duplex operation it is necessary...
Branch prediction has been playing an increasingly important role in improving the performance and energy efficiency for modern microprocessors. The state-of-the-art branch predictors, such as the perceptron and TAGE predictors, leverage novel prediction algorithms to explore longer branch history for higher prediction accuracy. We observe that as the branch history is becoming longer, the efficiency...
The new Binary Offset Carrier (BOC) modulated signals, where the pseudo random noise (PRN) code is multiplied with rectangular subcarriers, split the spectrum symmetrically and reduce interference with existing navigation signals. In spite of these benefits of the Autocorrelation Function (ACF) for BOC signals, e.g. better multipath mitigation and sharper correlation main peak for better tracking...
Adaptive beamforming algorithm performance decreases sharply with the increase of array errors. Beamforming algorithm based on diagonal loading is a simple and effective method for improving robustness. But it is difficult to determine the optimal diagonal loading factor, and the fixed load value does not change with the array error, reduce the loading effect. To solve the above problems, this paper...
This paper presents a weighted least squares algorithm for passive localization using Time Difference of Arrival in multipath scenarios. The algorithm is based on the direct or one-step approach for position estimation using distributed sensors and requires no knowledge about the number of received multipaths, the transmitted signal or the transmit time. Delayed signal paths arriving due to multipath...
In a multiuser MIMO broadcast channel, the rate performance is affected by the multiuser interference when the Channel State Information at the Transmitter (CSIT) is imperfect. To tackle the interference problem, a Rate-Splitting (RS) approach has been proposed recently, which splits one user's message into a common and a private part, and superimposes the common message on top of the private messages...
Time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) has higher spectral efficiency than standard cyclic prefix OFDM (CP- OFDM), which is achieved by using a known pseudorandom noise (PN) sequence to replace the classical CP. However, due to the interference between the PN sequence and the data block, the performance of TDS-OFDM degrades severely over fast fading channels...
In this paper, exact performance analyses of the noncoherent ultra-wideband differential transmitted reference systems are evaluated in the correlated Nakagami-m fading channels via applying the characteristic function (CF) method, where the correlated channel model is derived from the bivariate Nakagami-m distribution. Moreover, the independent Nakagami-m fading channel is considered as a special...
Transform Domain Communication System (TDCS) has been proposed as a new candidate applied in the cognitive radio (CR) environment since it can avoid existing users or jammers intelligently over a given bandwidth. The TDCS achieves noise-like property and orthogonality characteristic by generating a PR phase vector through a random phase coding processing. In this paper, a new implementation of TDCS...
Ultra-wideband (UWB) communication techniques are highly interesting because they seek to rearrange the huge spectrum of UWB for diverse applications. Therefore, UWB is the main technique employed in communication systems for 4G wireless networks. However, several issues in UWB technology, such as interference with various existing civil and military communication systems, require resolution. In this...
This paper considers the scenario when a mix of signals from multiple acoustic sources is received by a microphone array. The problem is to estimate the waveform of the source of interest located in the near field of the array. The considered problem can arise in many applications such as video conferencing, acoustic room surveillance and others, when it is necessary to capture human speech against...
In Compressed Sensing, a real-valued sparse vector has to be reconstructed from an underdetermined system of linear equations. However, in many applications of digital communications the elements of the unknown sparse vector are drawn from a finite set. The standard reconstruction algorithms of Compressed Sensing do not take this knowledge into account, hence, enhanced algorithms are required to achieve...
The desirable characteristics of ultra-wideband (UWB) technology are challenged by formidable sampling frequency, performance degradation in the presence of multi-user interference, and complexity of the receiver due to the channel estimation process. In this paper, a low-rate-sampling technique is used to implement M-ary multiple access UWB communications, in both the detection and channel estimation...
We consider joint adaptive transmit(TX) and receive (RX) beamforming for interference mitigation in array sensing systems. Unlike conventional designs, which only employ adaptive processing for the RX beamforming, we propose a fully adaptive approach that jointly selects the transmit correlation matrix and RX beamformer by maximizing the signal-to-interference-plus-noise ratio (SINR). Due to imprecise...
This paper considers optimal multi-carrier (multiple messages) spread-spectrum (SS) data embedding on linearly-transformed host. We present information-theoretic security analysis for the optimal SS embedding. The security is quantified by both the Kullback-Leibler distance and Bhat-tacharyya distance between the cover and stego probability distributions. The main results of this paper permit to establish...
Virtualization greatly improves resource utilization in IaaS platforms, but it also introduces potential interference between virtual machines (VMs). For example, VMs may suffer from performance degradation, when they are located in one host and compete for sharing physical resources. Thus, how to efficiently monitor and quantify the VMs interference becomes a key challenge for IaaS providers. In...
In many applications such as sensor networks, e-healthcare and environmental monitoring, data is continuously streamed and combined from multiple resources in order to make decisions based on the aggregated data streams. One major concern in these applications is assuring high trustworthiness of the aggregated data stream for correct decision-making. For example, an adversary may compromise a few...
To assess the reliability of marine propulsion shafting, an assessment model is established based on systemlevel stress — strength interference analysis, where the relationship between component failure probability attribute and stress-strength distribution was described. Different from the conventional system reliability estimation method by which system reliability was calculated directly from component...
Due to a wider range of services in future heterogeneous cellular network (HCN), packet transmission delay becomes a more essential performance metric for system design. In this paper, we propose an analytical framework to derive the delay performance of HCN in terms of local delay, by modeling the locations of base stations (BSs) in HCN as superimposed of independent Poisson point processes. In the...
Interferometric methods to obtain the three-dimensional spatial information and the continuous spectral information of a usual polychromatic object simultaneously without using coherent illumination, dispersion elements, or image forming elements (such as lens) have been recently investigated. These methods use interferometric techniques and signal processing only. These methods are based on measurement...
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