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Localization of Wireless Capsule Endoscope (WCE) inside the small intestine is a very challenging problem, which is very important for the diagnosis of certain diseases. Previous studies have shown that Time-of-Arrival (TOA) localization can be more effective than Received Signal Strength (RSS) based localization. Performance evaluation of TOA-based localization techniques for WCE requires understanding...
One problem in multiuser multiple-input multiple-output (MU-MIMO) systems is that the transmitted signal from a base station to a user is interfered by the signals to other users. MU-MIMO precoding has been proposed as an effective way to solve the problem. However, most existing precoding methods are mainly designed with zero-forcing (ZF) or minimum mean-square-error (MMSE) criterion and the performance...
As an application of interlaced bypass torus (iBT) interconnection networks, a 6D mesh/iBT network has been formed by replacing the 3D torus network in a 6D mesh/torus interconnect (Tofu) with a 3D iBT network, helping further reduce latencies. However, the routing algorithms good for the torus-based systems such as Blue Gene series may deadlock for the new network. This work proposes three deadlock-free...
In this paper, the interference mitigation problem in device-to-device (D2D) communication underlaying cellular networks using fractional frequency reuse (FFR) is studied. For such system, we propose a location based channel reusing scheme in which the D2D users in the inner region have a chance to reuse the channel resources of cellular users in the outer region of neighboring cells, and the D2D...
In this paper, a system based on time-hopping spread spectrum techniques for indoor visible light communications is studied via simulation. A 2-PPM modulation scheme is selected because it yields good results in wireless optical communications. Furthermore, the system allows for selecting the number of pulses per symbol to be transmitted and makes use of an optimum maximum-likelihood receiver for...
This paper analyzes the TCP incast problem in data centers by focusing on the relationships between the TCP throughput and the congestion control window size of TCP. The root causes of the TCP incast problem are explored and the essence of the current methods to smooth the TCP incast is well explained. To verify our analysis, extensive simulations are conducted. The simulation results are in conformity...
The contactless charging system has a wide application range and many advantages for portable consumer electronic products. Wireless power transfer (WPT) includes both the transmitter and the receiver which are in the state of resonance to achieve high efficiency. This paper presents a new multiple overlapping coil transmitter structure which enables the receiver has high efficiency within transmitter...
Efficient utilization of wireless bandwidth is a critical, if not the key, component of the wireless network architectures that balance availability and access. Cognitive Radio Networks (CRNs) are an important part of the solution to this problem. Common control channels (CCCs) for rendezvous in CRNs have limitations such as single point of failure, low scalability, and susceptibility to jamming attacks...
In this research, performance evaluation of timing synchronization on Orthogonal Frequency Division Multiplexing (OFDM) communication system under Additive White Gaussian Noise (AWGN) communication channel is done. The performance evaluation is done by comparing the existing time synchronization algorithms, here will be presented four types of algorithms to calculate the arrival time of OFDM symbol...
Synchronization technology is another key technology expcet for the equalization in SC-FDE, and it influeces the performance of the communication system in a certain degreee. The paper shows the princeple of SC-FDE and propose a synchronization scheme applied in HF communication based on the analysis of timing synchronization and frenquency offest compensation method. At last shows the simulation...
In multipath-assisted indoor navigation and tracking (MINT), explicit use is made of multipath propagation in the ultra-wideband channel. With the help of floorplan information, localization is possible with only one reference node. In this work, we introduce MINT among cooperating users in order to omit the need of any known reference nodes. The received signal is modeled as a combination of deterministic...
This paper compares the power efficiency of multiple 2D, 2.5D and 3D interconnect scenarios, specifically DDR3 with PCB, DDR3 with interposers, LPDDR2(3) with POP, wide I/Os with through-silicon vias (TSVs) and interposers and 32 nm technology CMOS drivers with TSVs and on-chip wires. It was found that DDR3 with PCB is the lowest power efficiency (15.65 mW/Gbps) and custom designed CMOS drivers optimized...
We describe in this paper the solutions adopted to fulfill the MIL-STD-188-110B standard HF modem requirements. We present the designs details of all the blocks of the standard such as channel encoding/decoding, matched filtering, digital modulation/demodulation, synchronization, and equalization. We deal also with channel modeling and provide performance analysis of the developed chain of communication.
This paper presents a model of direct delta-sigma receiver (DDSR) and methodology for theoretical transfer function (TF). The theoretical analysis is carried out by modeling the key elements of the DDSR, including the N-path filter, down-conversion mixer, baseband delta sigma modulator (DSM) and FIRDACs in order to optimize the loop filter coefficients. The contribution of different noise sources...
This paper studies the opportunistic spectrum access (OSA) of secondary users in a large-scale overlay cognitive radio (CR) network. Particularly, a threshold-based protocol is investigated, where the secondary transmitter is allowed to access the spectrum only if the maximum signal power of the received pilots sent from the primary transmitters is lower than a certain threshold. To measure the resulting...
In this paper, we proposes a new minimum distance based precoding scheme for closed-loop quasi-orthogonal spacetime block code (QO-STBC) systems. By utilizing the minimum Euclidean distance maximizing criterion, the proposed scheme attains the near-optimal symbol error performance, while allowing lower feedback overhead. In addition, the proposed scheme still guarantees a simple maximum likelihood...
Inter-Destination Multimedia Synchronization(IDMS) is a key requirement to enable satisfying group shared media experiences. This paper presents the design and simulation of a Distributed Control Scheme (DCS) for IDMS. In this scheme, geographically dispersed receivers exchange(multicast) RTCP reports on their arrival and play out timing for RTP packets, and each one of them uses the collected reports...
Mode Group Diversity Multiplexing (MGDM) is an Optical Multiple-Input-Multiple-Output (O-MIMO) technique that provides larger robustness and capacity for data communication over MultiMode Fiber (MMF). The utility of a MGDM system in terms of capacity expansion gives a major interest in most applications of optical communication. In this paper, we propose a transfer matrix decompositioon of O-MIMO...
Preamble sampling (or low-power listening) is a low-power technique used in wireless networks to allow nodes to check for waiting traffic by periodically waking up from a low-power sleep state. An increasing number of proposals exist in literature to provide static and adaptive solutions to implement preamble sampling. This paper tackles the important question of what is the optimal preamble sampling...
The next generation GNSS radio occultation instrument under development at RUAG Space will take advantage of the new signals of Galileo, GPS, GLONASS, and Compass. The measurement performance is improved as compared to the present instrument generation that operates on the MetOp satellites. A tracking algorithm has been developed which ensures that all signal information throughout the atmosphere...
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