In this paper a third-order inter-modulation cancellation technique using Pre-Post-Distortion is proposed to design a wideband high linear low-power LNA in deep submicron. The IM3 cancellation is achieved by post-distorting signal inversely after it is pre- distorted in the input trans-conductance stage during amplification process. The operating frequency range of the LNA is 800 MHz–5 GHz. The proposed technique increases input-referred third-order intercept point (IIP3) and input 1 dB Compression point (P-1 dB) to 12–25 dBm and -1.18 dBm, respectively. Post layout simulation results show a noise figure (NF) of 4.1–4.5 dB, gain of 13.7–13.9 dB and S11 lower than -13 dB while consumes 8 mA from 1.2 V supply. The LNA is designed in a 65 nm standard CMOS technology. The layout schematic shows that the LNA occupies 0.150.11 mm2 of silicon area.

We present a new multi-path routing methodology, MLB-routing, that is based on the multinomial logit model, which is well known in the random utility field. The key concept of the study is to set multiple paths from the origin to the destination, and distribute packets in accordance with multinomial logit type probability. Since MLB-routing is pure multi-path routing, it reduces the convergence on some links and increases bandwidth utilization in the network. Unlike existing multi-path routing schemes, which pre-set alternate paths, the proposed method can dynamically distribute packets to every possible path and thus is more efficient. Furthermore, it should be mentioned that this methodology can be implemented as either a link-state protocol or a distance-vector protocol. Therefore, it well supports the existing Internet. Simulations show that this methodology raises network utilization and significantly reduces end-to-end delay and jitter.

This paper presents the development of a sound–specific vibration interface and its evaluation results by playing three commercial games with the interface. The proposed interface complements the pitfalls of existing frequency–based vibration interfaces such as vibrating headsets, mouses, and joysticks. Those interfaces may bring negative user experiences by generating incessant vibrations because they vibrate in response to certain sound frequencies. But the proposed interface which responds to only target sounds can improve user experiences effectively. The hardware and software parts of the interface are described; the structure and the implementation of a wrist pad that delivers vibration are discussed. Furthermore, we explain a sound-matching algorithm that extracts sound characteristics and a GUI-based pattern editor that helps users to design vibration patterns. The results from evaluating the performance show that the success ratio of the sound matching is over 90% at the volume of 20 dB and the delay time is around 400 msec. In the survey about user experiences, the users evaluates that the interface is more than four times effective in improving the reality of game playing than without using the vibration interfaces, and two times than the frequency–based ones.

This paper proposes an active-RC filter that achieves a wide pseudo-continuous bandwidth-tuning range and a wide gain range with fine steps using a novel switched resistor architecture. A channel-selection filter with the proposed resistor bank is designed for a multi-mode mobile-TV receiver with the 6th order Chebyshev-I topology. The bandwidth, 0.5–6 MHz with 5% steps, supports multiple mobile-TV standards with sufficient margins for process and temperature variations. The filter also accomplishes a 30-dB variable gain range with 6-dB steps, and it relaxes the dynamic range requirement of a succeeding programmable gain amplifier. The power consumption of the filter, 3.4–5.0 mW, is adjustable according to the bandwidth and the signal level. The filter was fabricated with on-chip bandwidth-calibration circuitry in 0.18-µm CMOS and occupied 0.81 mm2.

In this letter, the reliabilty of the generalized normal-Laplace (GNL) distribution used for modeling the multiple access interference (MAI) plus noise in time-hopping (TH) binary phase-shift keying (BPSK) ultra-wideband (UWB) systems is evaluated in terms of the probability density function and the BER. The multiple access performance of TH-BPSK UWB systems based on GNL model is analyzed. The average BER performance obtained by using GNL approximation well matches with the exact BER results of TH-BPSK UWB systems. The parameter estimates of GNL distribution based on the moments estimation method is also presented.

This paper presents a new low-dropout (LDO) regulator with low-quiescent, high-drive and fast-transient performance. This is based on a new composite power transistor composed of a shunt feedback class-AB embedded gain stage and the application of dynamic-biasing schemes to both the error amplifier as well as the composite power transistor. The proposed LDO regulator has been simulated and validated using BSIM3 models and GLOBALFOUNDRIES 0.18-µm CMOS process. The simulation results have shown that the LDO regulator consumes 4.7 µA quiescent current at no load, regulating the output at 1 V from a minimum 1.2 V supply. It is able to deliver up to 450 mA load current with a dropout of 200 mV. It can be stabilized using a 4.7 µF output capacitor with a 0.1 Ω ESR resistor. The maximum transient output voltage is 64.6 mV on the basis of a load step change of 450 mA/10 ns under typical condition. The full load transient response is less than 350 ns.

Distance to target is fundamental and very important information in numerous engineering fields. Many distance measurement methods using sound use the time delay of a reflected wave, which is measured in reference to the transmitted wave. This method, however, cannot measure short distances because the transmitted wave, which has not attenuated sufficiently by the time the reflected waves are received, suppresses the reflected waves for short distances. Therefore, we proposed an acoustic distance measurement method based on the interference between the transmitted wave and the reflected waves, which can measure distance in a short range. The proposed method requires a cancellation processing for background components due to the spectrum of the transmitted wave and the transfer function of the measurement system in real environments. We refer to this processing as background components cancellation processing (BGCCP). We proposed BGCCP based on subtraction or whitening. However, the proposed method had a limitation with respect to the transmitted wave or additive noise in real environments. In the present paper, we propose an acoustic distance measurement method based on the new BGCCP. In the new BGCCP, we use the calibration of a real measurement system and the whitening processing of the transmitted wave and introduce the concept of the cepstrum to the proposed method in order to achieve robustness. Although the conventional BGCCP requires the recording of the transmitted wave under the condition without targets, the new BGCCP does not have this requirement. Finally, we confirmed the effectiveness of the proposed method through experiments in real environments. As a result, the proposed method was confirmed to be valid and effective, even in noisy environments.

In this letter, we derive another exact bit error rate (BER) for decode-and-forward (DF) relay systems over Rayleigh fading channels. At first, our focus is on fixed-DF (FDF) relay schemes in which the probability density function (PDF) is derived based on error-events at relay nodes. Some insight into how erroneous detection and transmission at relay nodes affect both the combined signal-to-noise ratio (SNR) and the averaged BER is obtained, and cooperative diversity is observed from the closed-form BER expression. In addition, the developed analytical method is extended to adaptive-DF (ADF) schemes and the exact BER expressions are derived. Simulation results are finally presented to validate the analysis.

This paper presents a grid-based, real-time surface modeling algorithm in which the generation of a precise 3D model is possible by considering the user's intention during the course of the spatial input. In order to create the corresponding model according to the user's input data, plausible candidates of wand traversal patterns of grid edges are defined by considering the sequential and directional characteristics of the wand input. The continuity of the connected polygonal surfaces, including the octree space partitioning, is guaranteed without the extra crack-patching algorithm and the pre-defined patterns. Furthermore, the proposed system was shown to be a suitable and effective surface generation tool for the spatial sketching system. It is not possible to implement the unusual input intention of the 3D spatial sketching system using the conventional Marching Cubes algorithm.

In this paper, side information refinement methods for Wyner-Ziv video codec are presented. In the proposed method, each block of a Wyner-Ziv frame is separated into a predefined number of groups, and these groups are interleaved to be coded. The side information for the first group is generated by the motion compensated temporal interpolation using adjacent key frames only. Then, the side information for remaining groups is gradually refined using the knowledge of the already decoded signal of the current Wyner-Ziv frame. Based on this basic concept, two progressive side information refinement methods are proposed. One is the band-wise side information refinement (BW-SIR) method which is based on transform domain interleaving, while the other is the field-wise side information refinement (FW-SIR) method which is based on pixel domain interleaving. Simulation results show that the proposed methods improve the quality of the side information and rate-distortion performance compared to the conventional side information refinement methods.

In this paper, we deal with the pedestrian detection task in outdoor scenes. Because of the complexity of such scenes, generally used gradient-feature-based detectors do not work well on them. We propose to use sparse 3D depth information as an additional cue to do the detection task, in order to achieve a fast improvement in performance. Our proposed method uses a probabilistic model to integrate image-feature-based classification with sparse depth estimation. Benefiting from the depth estimates, we map the prior distribution of human's actual height onto the image, and update the image-feature-based classification result probabilistically. We have two contributions in this paper: 1) a simplified graphical model which can efficiently integrate depth cue in detection; and 2) a sparse depth estimation method which could provide fast and reliable estimation of depth information. An experiment shows that our method provides a promising enhancement over baseline detector within minimal additional time.

Sender-based message logging (SBML) with checkpointing has its well-known beneficial feature, lowering highly failure-free overhead of synchronous logging with volatile logging at sender's memory. This feature encourages it to be applied into many distributed systems as a low-cost transparent rollback recovery technique. However, the original SBML recovery algorithm may no longer be progressing in some transient communication error cases. This paper proposes a consistent recovery algorithm to solve this problem by piggybacking small log information for unstable messages received on each acknowledgement message for returning the receive sequence number assigned to a message by its receiver. Our algorithm also enables all messages scheduled to be sent, but delayed because of some preceding unstable messages to be actually transmitted out much earlier than the existing ones.

Multiple-attribute based handoff schemes suffer from instability because of the dynamic nature of attributes and the distribution of handoff procedure over candidate networks, resulting in frequent handoffs that degrade the efficiency of resource management. To alleviate such instability, a service-history based scheme was proposed but it has several improper design decisions, e.g. it considers the history factors too optimistically and employs fixed weights that are likely to distort handoff decisions. This letter proposes to improve handoff performance by considering network state along with the service history. It takes into account the network utilization to avoid the optimistic dependency on the history and adaptively determines the weight to the service history in order to adjust its effect on the handoff decision. Simulation results show that the proposed scheme optimizes the number of handoff and the dropping probability when compared with existing schemes.

Wireless Sensor Networks (WSNs) are gradually moving toward the adoption of clustered heterogeneous designs, incorporating a mixture of variety kinds of sensor nodes with different radio coverage and battery capacity. Compared with homogeneous networks, heterogeneous networks are able to reduce the initial cost of the network or prolong the network lifetime. The architecture and routing protocol for this type of heterogeneous WSN should be energy aware in order to prolong the lifetime of the network. However, most of the existing clustering methods consider only initial energy of the sensor nodes and ignore the non-uniform energy drainage caused by many-to-one traffic near sink and/or cluster heads in heterogeneous network environment. In this paper, we propose a new clustering method for WSN with heterogeneous node types which selects cluster heads considering not only the transmission power and residual energy of each node but also those of its adjacent nodes. Simulation experiments show that the proposed method increases network lifetime by 80% and 60% more than that of the CC and HEED, respectively.

In this letter, a study on the end-to-end outage performance of dual-hop non-regenerative relaying in the presence of co-channel interference is presented. We assume that both the desired and the interfering signals are subjected to Nakagami-m fading. Exact analytical expressions, as well as tight lower bounds of the end-to-end outage probability, are derived. An asymptotic expression for the outage probability at high values of Signal-to-Interference Ratio is also presented. Furthermore, we also propose the optimal power allocation for high values of Signal-to-Interference Ratio. Extensive numerically evaluation and computer simulation results are presented to verify the validity and the accuracy of the proposed analysis.

In this paper, we study the problem of efficient processing of conjunctive queries in Peer-to-Peer systems based on Distributed Hash Tables (P2P DHT, for short). The basic idea of our approach is to cache the search result for the queries submitted in the past, and to use them to improve the performance of succeeding query processing. More concretely, we propose to adopt Bloom filters as a concrete implementation of such a result cache rather than a list of items used in many conventional schemes. By taking such an approach, the cache size for each conjunctive query becomes as small as the size of each file index. The performance of the proposed scheme is evaluated by simulation. The result of simulation indicates that the proposed scheme is particularly effective when the size of available memory in each peer is bounded by a small value, and when the number of peers is 100, it reduces the amount of data transmissions of previous schemes by 75%.

The past decade has seen a surge of research activities in the fields of mobile computing and wireless communication. In particular, recent technological advances have made portable devices, such as PDA, laptops, and wireless modems to be very compact and affordable. To effectively operate portable devices, energy efficiency and Quality of Service (QoS) provisioning are two primary concerns. Dynamic Voltage Scaling (DVS) is a common method for energy conservation for portable devices. However, due to the amount of data that needs to be dynamically handled in varying time periods, it is difficult to apply conventional DVS techniques to QoS sensitive multimedia applications. In this paper, a new adaptive DVS algorithm is proposed for QoS assurance and energy efficiency. Based on the repeated learning model, the proposed algorithm dynamically schedules multimedia service requests to strike the appropriate performance balance between contradictory requirements. Experimental results clearly indicate the performance of the proposed algorithm over that of existing schemes.

The aim of this study is to realize a simplified gait analysis system using wearable sensors. In this paper, a joint angle measurement method using Kalman filter to correct gyroscope signals from accelerometer signals was examined in measurement of hip, knee and ankle joint angles with a wireless wearable sensor system, in which the sensors were attached on the body without exact positioning. The lower limb joint angles of three healthy subjects were measured during gait with the developed sensor system and a 3D motion measurement system in order to evaluate the measurement accuracy. Then, 10 m walking measurement was performed under different walking speeds with a healthy subject in order to find the usefulness of the system as a simplified gait analysis system. The joint angles were measured with reasonable accuracy, and the system showed joint angle changes that were similar to those shown in a previous report as walking speed changed. It would be necessary to examine the influence of sensor attachment position and method for more stable measurement, and also to study other parameters for gait evaluation.

Detecting distributed anomalies rapidly and accurately is critical for efficient backbone network management. In this letter, we propose a novel anomaly detection method that uses router connection relationships to detect distributed anomalies in the backbone Internet. The proposed method unveils the underlying relationships among abnormal traffic behavior through closed frequent graph mining, which makes the detection effective and scalable.

A low-complexity Reed-Solomon (RS) decoder design based on the modified Euclidean (ME) algorithm proposed by Truong is presented in this paper. Low complexity is achieved by reformulating Truong's ME algorithm using the proposed polynomial manipulation scheme so that a more compact polynomial representation can be derived. Together with the developed folding scheme and simplified boundary cell, the resulting design effectively reduces the hardware complexity while meeting the throughput requirements of optical communication systems. Experimental results demonstrate that the developed RS(255, 239) decoder, implemented in the TSMC 0.18 µm process, can operate at up to 425 MHz and achieve a throughput rate of 3.4 Gbps with a total gate count of 11,759. Compared to related works, the proposed decoder has the lowest area requirement and the smallest area-time complexity.