Pseudorandom number generation (PRNG) is the basic security tool for the EPC Gen2 tags. Commercial EPC Gen2 PRNGs have been analyzed obtaining link layer communication data. Evidences have been found that different commercial integrated circuits use the same PRNG algorithm.

In order to eliminate the intersymbol interference as well as the intercarrier interference, a cyclic prefix (CP) is appended to each orthogonal frequency division multiplexing symbol. By using the frequency domain equivalence of the time domain circular convolution in the CP interval, we propose a novel method to estimate the timing offset blindly.

The problems encountered in nonlinear adaptive coding are addressed by employing, for the first time, several kernel adaptive algorithms in the framework of speech coding using backward adaptive differential pulse code modulation technique. Particular attention is focused on the effect of various sparsification techniques on the performance of the resultant algorithms. Results show an average improvement of up to 3.4 dB in the signal-to-noise ratio criterion of the reconstructed speech utilizing kernel methods.

We study downlink beamforming and resource optimisation in multicell multi-input single-output orthogonal frequency division multiple access systems. We propose an efficient suboptimal algorithm using uplink downlink duality.

In this work, a theoretical performance analysis of acknowledgement (ACK)-based and non-acknowledgement (NoACK)-based transmission mechanisms is presented. The evaluation considers both point-to-point and point-to-multipoint models. Extensive simulations show that ACK-based and NoACK-based implementations produce a similar performance on the flooding delay, but with significantly different costs on the energy consumption.

We discuss the amount of energy that can be saved using a cluster-based approach. We propose a novel cluster head selection algorithm by considering the required power level for sending a packet from the cluster node to the cluster head, which is complemented by a prediction mechanism to reduce the number of data transmissions. We implement our cluster-based algorithm on a test bed using the k-nearest-neighbor algorithm and show that it can achieve high accuracy (above 90%).

The binary-symmetric parallel-relay network is studied. It is shown that forwarding relays achieve the capacity when the number of relays is medium to large and that decoding relays achieve the capacity when the number of relays is small.

In this article, the limitations of conventional spectrum sensing at discovering spatial spectrum hole are highlighted and an interference-aware sensing metric is adopted to maximize the spectrum hole utilization for a secondary user. Specifically, we introduce a new degree of freedom, transmit power adaptation, into the issue of interference-aware spectrum sensing and develop a joint optimization problem to maximize the interference-free throughput of the secondary user while satisfying the quality of service constraints of both the primary and secondary transmissions.

We propose the tool support based on the ontology adaptation service quality, and we propose a new approach to automatically assemble dynamic quality and semantic adaptation services. We show by a case study how to easily govern the response time and the quality assembly of mobile applications at runtime.

Sparse sampling of uncoded signals at sampling rates exceeding the Landau rate is well established. We examine sampling of coded signals at sub-Landau rates. Then the Landau condition may be relaxed, and the sampling rate can be lower than the effective bandwidth. Tight bounds on information rates and on signal recovery are derived. When the system is high-dimensional, the required SNR is finite but high, it can be lowered by concentrating the frequency support into a finite number of subbands.

This work provides a novel measurement-based analysis of the tweet arrival traffic process at Twitter. The analysis considers more than one million total tweets collected at 48 different times of the day. We observe a 3.5-tweet/ms average rate with a valley of 2.5 tweets/ms at 10 AM (GMT+1) and a peak at 3 PM (GMT+1) of about 5 tweets/ms. We further model the traffic pattern as a Gaussian process, and we validate such an assumption with multiple normality tests.