nils-herrmann/clean_scirepeval huggingface dataset:
Distributed Signal Compressive Quantization and Parallel Interference Cancellation for Cloud Radio Access Network

The explosive growth of wireless traffic requires revolutionary wireless communication techniques. The cloud radio access network (C-RAN) is a solution to leverage the spatial multiplexing gain by utilizing a number of antennas distributed in a certain area. However, in most of the current literature, due to the limited front-haul capacity, each remote radio head (RRH) can use only a single antenna, and thus the total number of antennas can be utilized are limited. In this work, we propose a distributed baseband signal compressive quantization scheme for the uplink of a multi-antenna C-RAN where each RRH uses multiple antennas. At each RRH, the baseband signals of multiple time instants are embedded into a vector with low dimension using delay-and-add so that more bits can be allocated to each value, and the quantization noise power caused by the front-haul link capacity deficit is reduced. The delay-and-add operation is low complexity that can be realized using basic buffering and adding, and it does not require channel information in the RRHs. Therefore, the low deployment cost feature of C-RAN is preserved. As a result, a large number of antennas can be utilized by deploying a lot of multi-antenna RRHs, which provide rich spatial diversity that assists the detection which happens in the baseband units. In the symbol detection phase, the corresponding weight vectors are designed to detect the symbols from the compressive quantized baseband signal. A parallel interference cancellation algorithm is proposed to further improve the accuracy of the symbol detection. Numerical results show that the proposed scheme is efficient in tackling the front-haul capacity challenge. We also apply the proposed scheme to orthogonal frequency-division multiplexing-based multi-antenna C-RAN, where we find that the system can utilize larger bandwidth with limited front-haul capacity. It facilitates the deployment of C-RAN based on both 4G and 5G wireless communications.
A Scalable Multiuser Framework for Video Over OFDM Networks: Fairness and Efficiency

In this paper, we propose a framework to transmit multiple scalable video programs over downlink multiuser orthogonal frequency division multiplex (OFDM) networks in real time. The framework explores the scalability of the video codec and multidimensional diversity of multiuser OFDM systems to achieve the optimal service objectives subject to constraints on delay and limited system resources. We consider two essential service objectives, namely, the fairness and efficiency. Fairness concerns the video quality deviation among users who subscribe the same quality of service, and efficiency relates to how to attain the highest overall video quality using the available system resources. We formulate the fairness problem as minimizing the maximal end-to-end distortion received among all users and the efficiency problem as minimizing total end-to-end distortion of all users. Fast suboptimal algorithms are proposed to solve the above two optimization problems. The simulation results demonstrated that the proposed fairness algorithm outperforms a time division multiple (TDM) algorithm by 0.5 ~ 3 dB in terms of the worst received video quality among all users. In addition, the proposed framework can achieve a desired tradeoff between fairness and efficiency. For achieving the same average video quality among all users, the proposed framework can provide fairer video quality with 1 ~ 1.8 dB lower PSNR deviation than a TDM algorithm
On the Equivalence of Evolutionary Stable Strategies

Evolutionary game theory (EGT) has been widely adopted in various research fields and recently drawn great attentions in communications and networking. It is considered as an effective tool to analyze how a group of players converges to a stable equilibrium after a period of strategic interactions. Such an equilibrium strategy is defined as the evolutionarily stable strategy (ESS). There are two formal definitions for the ESS, where one of them is a literally mathematical interpretation and the other is a refined Nash equilibrium illustration, and both of them are widely used in the literature. However, the equivalence of these two definitions has not been well investigated. In this letter, we theoretically prove the equivalence of them under some sufficient condition. Moreover, we also show that the sufficient condition is general in communications and networking areas by introducing two examples.
An Adaptive Protocol for Cooperative Communications Achieving Asymptotic Minimum Symbol-Error-Rate

This paper investigates the protocol design issue for cooperation systems in wireless communications. A tight approximate symbol error rate (SER) for such systems is derived and analyzed. Based on such analysis, an optimum power allocation scheme is proposed by optimizing the derived approximate SER subject to fixed transmission rate and total transmit power constraints. Then, a novel adaptive protocol is proposed for cooperative communications based on minimizing the asymptotic SER (i.e. in an averaging sense under high-enough SNR regimes) of such systems. This proposed adaptive protocol is able to achieve the maximum achievable diversity gain available in such systems without sacrificing any transmission rate or the total transmit power, and optimally adapts the number of cooperation partners under the changing environments. Simulation results show that the proposed adaptive protocol provides a lower SER compared with existing protocols. In addition, the proposed adaptive protocol with optimum power allocation can remarkably enhance the SER performance in comparison with the equal power allocation scheme
Defense Against Injecting Traffic Attacks in Wireless Mobile Ad-Hoc Networks

In ad-hoc networks, nodes need to cooperatively forward packets for each other. Without necessary countermeasures, such networks are extremely vulnerable to injecting traffic attacks, especially those launched by insider attackers. Injecting an overwhelming amount of traffic into the network can easily cause network congestion and decrease the network lifetime. In this paper, we focus on those injecting traffic attacks launched by insider attackers. After investigating the possible types of injecting traffic attacks, we have proposed two sets of defense mechanisms to combat such attacks. The first set of defense mechanisms is fully distributed, while the second is centralized with decentralized implementation. The detection performance of the proposed mechanisms has also been formally analyzed. Both theoretical analysis and experimental studies have demonstrated that under the proposed defense mechanisms, there is almost no gain to launch injecting traffic attacks from the attacker's point of view
Primary-Prioritized Markov Approach for Dynamic Spectrum Access

In order to fully utilize the scarce spectrum resources, with the development of cognitive radio technologies, dynamic spectrum access becomes a promising approach to increase the efficiency of spectrum usage. The spectrum access can be designed in an opportunistic way to efficiently and fairly share the spectrum resources among multiple unlicensed users, while not disturbing primary users' spectrum usage. In this paper, we propose a primary-prioritized Markov approach for dynamic spectrum access through modeling the interactions between the primary users and the unlicensed users as continuous- time Markov chains (CTMC). By designing appropriate access probabilities for the unlicensed users, the spectrum dynamics can be captured using CTMC models to optimally coordinate the spectrum access of the unlicensed users so that a good tradeoff can be achieved between the spectrum efficiency and fairness. The simulation results show that the proposed primary-prioritized dynamic spectrum access approach under proportional fairness criterion not only provides fair spectrum sharing among unlicensed users with only small performance degradation compared to the approach maximizing the overall average throughput, but also achieves much higher throughput than CSMA-based random access approaches and the approach achieving max-min fairness.
Optimization of Input Pattern for Semi Non-Intrusive Component Forensics of Digital Cameras

This paper considers the problem of semi non-intrusive component forensics and proposes a methodology to identify the algorithms and parameters employed by various processing modules inside a digital camera. The proposed analysis techniques assume the availability of the camera; and introduce a forensic methodology to estimate the parameters of the color interpolation and white balancing algorithms employed in cameras. We devise testing conditions, and design good input patterns to improve the overall accuracy in parameter estimation. As demonstrated by the results in the paper, the proposed techniques provide a much lower estimation bias and variance compared to non-intrusive analysis. The features obtained from component forensic analysis provide useful evidence for such applications as analyzing technology evolution trend, detecting technology infringement/licensing, protecting intellectual property rights, and determining camera source.
Energy-efficient cooperative transmission over multiuser OFDM networks: who helps whom and how to cooperate

Cooperative transmission has been shown to be able to greatly improve the system performance by exploring the broadcasting nature of wireless channels and cooperation among users. While most existing works concentrate on improving the peer-to-peer link quality, we focus, in this paper, on resource allocation among users such that the system performance can be improved. In this work, two important questions are answered: who should help whom among the distributively located users; and how the users should cooperate to improve the performance. To quantify the questions, a power management problem is formulated over a multiuser OFDM network to minimize the overall system transmit power under the constraint of each user's desired transmission rate. Then, we develop an algorithm to find solutions for a two user case. From the simulation results, the proposed scheme achieves up to 50% overall power saving for the two-user system.
Recursive LS filtering using block Householder transformations

A systolic block Householder transformation is proposed to implement the HT (Householder transformation) on a systolic array as well as to apply it to the RLS algorithm. Since the data are fetched in a block manner, vector operations are in general required for the vectorized array. The approach makes the HT suitable for VLSI implementation as well as applicable to real-time high-throughput applications of modern signal processing.<<ETX>>
The hierarchical timing pair model for multirate DSP applications

The problem of representing timing information associated with functions in a dataflow graph is considered. This information is used for constraint analysis during behavioral synthesis of appropriate architectures for implementing the graph. Conventional models for timing suffer from shortcomings that make it difficult to represent timing information in a hierarchical manner for sequential and multirate systems. Some of these shortcomings are identified, and an alternate timing model that does not have these problems for hardware implementations is provided. We introduce the concept of timing pairs to model delay elements in sequential and multirate circuits and show how this allows us to derive hierarchical timing information for complex circuits. The resulting compact representation of the timing information can be used to streamline system performance analysis. In addition, several analytical results that previously applied only to single rate systems can now be extended to multirate systems. We present an algorithm to compute the timing parameters and have used this to compute timing parameters for a number of benchmark circuits. The results obtained on several ISCAS benchmark circuits as well as several multirate dataflow graphs corresponding to useful signal processing applications are presented. These results show that the new representation model can result in large reductions in the amount of information required to represent timing for hierarchical systems.
Performance analysis for adaptive channel estimation exploiting cyclic prefix in multicarrier modulation systems

Multicarrier modulation (MCM) has gained growing interest in high-data-rate communications in both wire and wireless environments. The channel estimation is a crucial aspect in MCM systems. In this paper, we first present a novel adaptive channel estimation algorithm exploiting the channel information contained in the cyclic prefix of the MCM system. In simulation, we show that this algorithm outperforms the existing scheme. Then we theoretically analyze the performance of the adaptive algorithm considering both channel noise and decision error. We prove that the algorithm is guaranteed to converge with proper loading. Computer simulation shows that our analytical results are quite close to the simulation.
Distributed State Estimation With Dimension Reduction Preprocessing

System state estimation relies heavily on the measurements. With the advance of sensing technology, the ability to measure is no longer a bottleneck in many systems, and more and more researchers now focus on the rich-information setting, i.e., big data. However, although information never hurts, it does not help unconditionally. How to make the most of it depends on whether we can process the data efficiently. In some systems, the inherent constraint such as the bandwidth and cost makes it necessary to reduce the dimension of the measurement before further processing. The problem that the raw measurements are first preprocessed to reduce size and then used for estimation is addressed in this paper. It is shown that there is a lower bound on the size of the preprocessed data such that if the size is beyond the bound, there exists a closed-form estimator design that the linear minimum mean-square estimation can be obtained. Moreover, we propose an algorithm that is guaranteed to converge to a stationary point to design an estimator in the conditions that the lower bound cannot be reached. Besides convergence, the proposed algorithm guarantees bounded performance loss compared with the global optimal solution under some additional conditions. Finally, simulation results in three different applications are shown to demonstrate the effectiveness of the proposed algorithm.
Efficient architecture and design of an embedded video coding engine

By doubling the accuracy of motion compensation from integer-pel to half-pel, we can significantly improve the coding gain. Therefore, in this paper, we propose a novel COordinate Rotation Digital Computer (CORDIC) architecture for combined design of discrete cosine transform (DCT) and half-pel motion estimation. Unlike the conventional block matching approaches based on interpolated images, our CORDIC design can directly extract motion vectors at half-pel accuracy in the transform domain without interpolation. Compared to the conventional block matching methods with interpolation, our multiplier-free design achieves significant hardware saving and far less data flow. Our emphasis in this paper is on achieving efficient design of video coding engine by minimizing computational units along the data path. Furthermore, we implement the embedded design on a dedicated single chip to demonstrate its performance. The DCT-based nature of our design enables us to efficiently combine both DCT and motion estimation units, which are the two most important components of many multimedia standards consuming more than 80% of computing power for a video coder, into one single component. As a result, we can provide a single chip solution for video coding engine while many conventional designs may require multiple chips. In addition, all multiply-and-add (MAC) operations in plane rotations are replaced by CORDIC processors with simple shift-and-add, which is quite simple and compact to realize while being no slower than the bit serial multipliers widely proposed for VLSI array structures. Based on the test result, our chip can operate at 20 MHz with 0.8-/spl mu/m CMOS technology. Overall, we provide a low-complexity, high throughput solution in this paper for MPEG-1, MPEG-2, and H.263 compatible video codec design.
Peer-to-peer file sharing game using correlated equilibrium

Peer-to-peer (P2P) systems have become more and more popular in nowadays by providing decentralized, self-organizing and fault tolerant file sharing services. As the selfish users do not benefit from providing free service, they tend to download files from other users and yet not to upload for the others, resulting in low system efficiency. In this paper, we propose a correlated equilibrium-based file sharing game to enhance users' performance. We first characterize users' utility with their expected delay. Then, using the correlated equilibrium concept, instead of optimizing their own benefits alone, the users are aware of the best response for them to jointly optimize their strategies together and achieve the correlated equilibrium. Simulation results are presented to demonstrate the efficiency of the proposed scheme.
Design Criteria and Performance Analysis for Distributed Space-Time Coding

In this paper, the design of distributed space-time (ST) codes for wireless relay networks is considered. Distributed ST coding (DSTC) can be achieved through node cooperation to emulate a multiple-antenna transmitter. First, the decode-and- forward (DAF) protocol, in which each relay node decodes the symbols received from the source node before retransmission, is considered. An ST code designed to achieve full diversity and maximum coding gain over multiple-input-multiple-output (MIMO) channels is proven to achieve full diversity but not necessarily maximize the coding gain if used with the DAF protocol. Next, the amplify-and-forward (AAF) protocol is considered; each relay node can only perform simple operations, such as linear transformation of the received signal and amplification of the signal before retransmission. An ST code designed to achieve full diversity and maximum coding gain over MIMO channels is proven to achieve full diversity and maximum coding gain if used with the AAF protocol. Next, the design of DSTC that can mitigate the relay node synchronization errors is considered. Most of the previous works on cooperative transmission assume perfect synchronization between the relay nodes, which means that the relays' timings, carrier frequencies, and propagation delays are identical. Perfect synchronization is difficult to achieve among randomly located relay nodes. To simplify the synchronization in the network, a diagonal structure is imposed on the ST code used. The diagonal structure of the code bypasses the perfect synchronization problem by allowing only one relay node to transmit at any time slot. Hence, it is not necessary to synchronize simultaneous "in-phase" transmissions of randomly located relay nodes, which greatly simplifies the synchronization among the relay nodes. The code design criterion for distributed ST codes based on the diagonal structure is derived. This paper shows that the code design criterion maximizes the minimum product distance.
Parallel and Fully-Pinelined Instantaneous Optimal Weight Extraction for Adaptive Beamforming Using Systolic Arrays

Systolic algorithms and architectures for parallel and fully pipelined instantaneous optimal weight extraction for multiple sidelobe canceller (MSC) and minimum variance distortionless response (MVDR) beamformer are presented The proposed systolic parallelogram array processors are parallel and fully pipelined, and they can extract the optimal weights instantaneously without the need for forward or backward substitution. We also show that the square-root-free Givens method can be easily incorporated to improve the throughput rate and speed up the system. As a result these MSC and MVDR systolic array weight extraction system are suitable for real-time very large scale integration (VLSI) implementation in practical radar/sonar system.
Incentive Cooperation Strategies for Peer-to-Peer Live Multimedia Streaming Social Networks

Multimedia social networks have become an emerging research area, in which analysis and modeling of the behavior of users who share multimedia are of ample importance in understanding the impact of human dynamics on multimedia systems. In peer-to-peer live-streaming social networks, users cooperate with each other to provide a distributed, highly scalable and robust platform for live streaming applications. However, every user wishes to use as much bandwidth as possible to receive a high-quality video, while full cooperation cannot be guaranteed. This paper proposes a game-theoretic framework to model user behavior and designs incentive-based strategies to stimulate user cooperation in peer-to-peer live streaming. We first analyze the Nash equilibrium and the Pareto optimality of two-person game and then extend to multiuser case. We also take into consideration selfish users' cheating behavior and malicious users' attacking behavior. Both our analytical and simulation results show that the proposed strategies can effectively stimulate user cooperation, achieve cheat free, attack resistance and help to provide reliable services.
WiSpeed: A Statistical Electromagnetic Approach for Device-Free Indoor Speed Estimation

Due to the severe multipath effect, no satisfactory device-free methods have ever been found for indoor speed estimation problem, especially in non-line-of-sight (LOS) scenarios, where the direct path between the source and observer is blocked. In this paper, we present WiSpeed, a universal low-complexity indoor speed estimation system leveraging radio signals, such as commercial WiFi, LTE, 5G, etc., which can work in both device-free and device-based situations. By exploiting the statistical theory of electromagnetic waves, we establish a link between the autocorrelation function of the physical layer channel state information and the speed of a moving object, which lays the foundation of WiSpeed. WiSpeed differs from the other schemes requiring strong LOS conditions between the source and observer in that it embraces the rich-scattering environment typical for indoors to facilitate highly accurate speed estimation. Moreover, as a calibration-free system, WiSpeed saves the users’ efforts from large-scale training and fine-tuning of system parameters. In addition, WiSpeed could extract the stride length as well as detect abnormal activities such as falling down, a major threat to seniors that leads to a large number of fatalities every year. Extensive experiments show that WiSpeed achieves a mean absolute percentage error of 4.85% for device-free human walking speed estimation and 4.62% for device-based speed estimation, and a detection rate of 95% without false alarms for fall detection.
Full custom VLSI implementation of high-speed 2-D DCT/IDCT chip

Presents a full-custom VLSI design of high-speed 2-D DCT/IDCT processor based on the new class of time-recursive algorithms and architectures which has never been implemented to demonstrate its performance. The authors show that the VLSI implementation of this class of DCT/IDCT algorithms can easily meet the high-speed requirements of HDTV due to its modularity, regularity, local connectivity, and scalability. The design of the 8×8 DCT/IDCT can operate at 50 MHz with a 400 Mbps throughput based on a very conservative estimate under 1.2μ CMOS technology.