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Jamming attacks are considered one of the most devastating attacks as they are difficult to prevent and sometimes hard to detect. In this paper we consider the impact of the placement and range of limited-range jammers on ad hoc networks. Limited range jammers are more difficult to detect as they use transmission powers similar to that of regular nodes (or perhaps even smaller transmit powers). The...
Noise has traditionally been suppressed or eliminated in seismic data sets by the use of Fourier analysis filters and, to a lesser degree, nonlinear statistical filters. Although these methods are quite useful under specific conditions, they produce undesirable effects when denoising features of moderate to large amplitude and spatial extent, especially for the low S/N data. In this paper, a new method...
A feedback mechanism of the Page test is proposed in this paper. From the aspects of SNR estimation on square output of the matched filter, normalization, and the gate calculation, the information feedback flow is discussed. A new one-threshold Page test and processing flow that can effectively distinguish between target and interferences by cumulating change process adequately are also proposed....
Bit-interleaved coded modulation with iterative decoding (BICM-ID) is suitable for the next-generation wireless communication systems. BICM-ID is a bandwidth efficient transmission scheme. And the high performance of BICM-ID depends on the interleaver design. This paper focuses on the design of golden based interleaving schemes in BICM-ID systems. It shows that the golden interleaver and the dithered...
In this paper, we present short communication schedules for broadcast, data aggregation, data gathering, and gossiping in multihop wireless networks subject to physical interference. We assume that all communications proceed in synchronous time-slots, each node can transmit at most one packet of fixed size in each time-slot, and all nodes have fixed and equal transmission power. Under mild assumptions,...
A wireless ad hoc network (WANET) is a collection of wireless terminals that communicate with each other without predetermined topology. Since WANET devices are power-limited, network protocols should be designed to prolong the battery lifetime of these devices. In this paper, we propose a cross-layer integration approach for power efficient routing protocol. The proposed cross-layer integration between...
In the paper, to solve the problem that some existing methods of separating the weak signals from mixed chaotic signals have to use certain priori knowledge of chaotic signals such as the inherent properties, a FastICA method based on the negentropy is employed to separate the weak signals from the unknown mixed chaotic signals blindly. According to the maximum nongaussianity which is one of the basic...
The antenna diversity based on log-likelihood ratio (LLR) is a new technology which is better than that based on signal-to-noise ratio (SNR) in performance. In this paper, we derive the expressions of transmit antenna selection schemes based on SLLR and BLLR over MIMO Nakagami channel. The average bit-error rate (BER) performance of M-ary on the correlated fading channel simulated by the Kronecker...
In this paper, we study the channel-aware minimum-latency broadcast scheduling problem using the probabilistic model. We establish an explicit relationship between the tolerated transmission-failure probability and the latency of the corresponding broadcast schedule. Such a tolerated transmission-failure probability is calculated in the strict sense that the failure to receive the message at any single...
The distributed queuing with collision avoidance (DQCA) medium access control (MAC) protocol has been presented in the literature as a high-performance protocol for uplink traffic in WLANs. Previous works regarding DQCA are focused on the operation of a single cell, where no interaction with neighboring sites is considered. In this paper, we define specific handoff functions (channel sensing, discovery...
In this paper, we offer a simple but general framework for analyzing the statistical properties of mobile-to-mobile (M2M) fading channels. Differently from other contributions that can be found in the literature, we are interested in end-to-end performance metrics rather than in simply analyzing the statistical behavior of the so-called product channel. As a consequence, our proposed framework is...
In hybrid automatic repeat request (HARQ) process, a retransmission occurs on the condition that the first transmission failed. Multiple received packets are combined for detection at the receiver. Equivalent noise after combining is not additive Gaussian white noise and not independent on the transmitted signal. Unfortunately, the assumption of zero-mean-Gaussian and independent noise after combining...
To achieve full transmission rate for complex signals, quasi orthogonal space-time block coding has been proposed while sacrificing the full diversity. However, due to complex channel condition its performance needs to be improved via antenna selection (AS). Moreover, to achieve utterly orthogonal performance against OSTBC, quasi-orthogonal STBC can still be improved combining pre-coding and antenna...
We consider a Gaussian multiple-access relay channel with multiple sources, a relay and a destination. We assume that the received signals at the relay and the destination from different nodes are orthogonal. Additionally, we assume that the relay performs an instantaneous mapping to compress all received signals from different sources into one output symbol. We refer to this as analog network coding...
Binaural cue coding, which is a representing low bit-rate coding of multichannel audio, generates large distortion when the audio data have complex spatial image, such as symphony. Such distortion caused by the low frequency resolution of spatial information because BCC quantizes the parameters of localization. In this paper we propose a new coding framework by quantizing the spatial information temporally...
Energy efficiency is a considerable criterion in design of wireless sensor networks. MIMO technology has the potential of supporting a higher data rate under a lower power budget and bit-error-rate, which makes cooperative MIMO in WSNs a popular research topic. This paper investigates a cluster-based time division cooperative MIMO communication system for WSNs. An optimum algorithm for the power and...
In this paper we study the problem of finding capacity-maximizing constellations in BICM for asymptotically low signal-to-noise ratios (SNRs). We base our analysis on the so-called Hadamard transform and on a linear approximation of the BICM capacity for asymptotically low SNRs. We fully characterize the set of constellations, input distributions, and binary labelings that achieve Shannon's limit...
In this paper, we study the diversity-multiplexing tradeoff (DMT) of a novel decode or quantize and forward (DoQF) protocol for the half duplex single relay channel. It is well-known that the so-called dynamic decode and forward (DDF) achieves the multiple-input-single-output (MISO) bound in the range of multiplexing gains r < 0.5. But to the best of our knowledge, no practical coding scheme allows...
We analyze multiuser detection under the assumption that the number of users accessing the channel is unknown by the receiver. Our main goal is to determine the performance loss caused by the need for estimating the identities of active users, which are not known a priori. To prevent a loss of optimality, we assume that identities and data are estimated jointly, rather than in two separate steps....
This paper presents an approach to the construction of low-density parity-check (LDPC) codes based on hyperplanes (mu-flats) of different dimensions in Euclidean geometries. Codes constructed by this method have quasicyclic and irregular structure. The degree distributions of these codes are optimized by the curve fitting approach in the extrinsic information transfer (EXIT) charts. By constraining...
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