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A single-user state-dependent channel with mismatched decoding is considered. Several setups are studied, which differ by the manner in which the state information is available to the encoder (causally or non-causally), and by whether or not the decoder is cognizant of the state sequence. We present achievable rates for these channels based on random coding and random binning and we also observe special...
In this paper, a cooperative spectrum sharing protocol with quality-of-service (QoS) support for both of the primary and secondary systems is proposed. Specifically, the secondary system gains primary spectrum access by allocating a fraction of its power to forward the primary signal helping the primary system achieve the target rate, and meanwhile exploits the remaining power to transmit its own...
Estimation of the electromagnetic field strength—intensity as well as polarization—is required to achieve accurate near real time modeling and prediction of high frequency (HF) channel response. We develop a novel approach for calculating these estimates using a combination of Delaunay triangulations and modified Gaussian ray bundles. This method allows for field intensity estimates at single-point...
Conference lecture rooms are considered as an indoor environment for research with indoor localization that faces different challenges. In this paper, we design an indoor localization system in such a complex environment focus on machine learning algorithms with a large scale data. In this system, users can get information where a specified people locate in. Our system has two main sections: system...
Interference between frequency hopping (FH) systems sharing the same frequency band can decrease the communication performance. The decrease can be severe, especially for systems on the same platform or in the vicinity of each other. Interference can stem both from sharing the same frequency channel momentarily or from adjacent channels. It is shown that a devastating high error floor can appear when...
We consider the problem of angle-of-arrival (AoA) estimation of a RF transmitter using a mobile receiver. We develop a method very similar to synthetic aperture radar which is compatible with cellular technology. By considering the successive packets received along the receiver trajectory, we implicitly create a virtual MIMO array, which allows us to utilize conventional MIMO theory for AoA estimation...
We propose a method for tracking a moving receiver using RF messages broadcasted from opportunistic beacons. The beacons are not required to be synchronized with each other or with the receiver. By measuring the time-of- arrival (TOA) of the RF messages transmitted from the beacons at different locations along the receiver's trajectory, the receiver is able to track its own location, velocity and...
It is well recognized in the literature that the performance of the hybrid automatic repeat request (HARQ) transmission can be improved by adapting the transmission parameters through exploiting extra information from the receiver over the feedback channel. This introduces new degrees of freedom for a more flexible per-link optimized transmission. This paper proposes a framework considering the practical...
Timing-based indoor positioning requires synchronization of the anchors that are distributed in space. Many synchronization techniques have been proposed, but implementing them in practice is extremely challenging, especially for networks with a large number of anchors. In this paper, a new synchronization-free localization model for timing-based indoor positioning is proposed. This scheme employs...
The explosive detection via NQR is based on presence of 14N as all explosives usually contain nitrogen. The detected nitrogen nuclei contained in explosives and other nitrogen containing materials gives different frequencies and also different explosives have their own NQR frequencies, explosives can be detected and uniquely identified by 14N NQR frequency. A Review on research and development in...
This paper presents a simple and cost effective method for radio tomographic imaging (RTI) using extremely resource constrained devices. The idea is to measure and analyse packet loss rates under various power levels and obtain images of objects in an interested area. We have implemented an experimental prototype for the RTI system using extremely resource constrained devices and results show that...
The problem of estimating receiver-sender node positions from measured receiver-sender distances is a key issue in different applications such as microphone array calibration, radio antenna array calibration, mapping and positioning using ultra-wideband and mapping and positioning using round-trip-time measurements between mobile phones and Wi-Fi-units. Thanks to recent research in this area we have...
In this paper, we present the design and implementation of a high precision Indoor Positioning System (IPS), with average accuracy within 0.5 meter and 90% of positioning errors smaller than 0.9m in three trial environments. The transmitter continuously transmitted periodic PN code and the multiple receivers at fixed locations performed signal acquisition, tracking, and position calculation. Several...
To understand the utilization of clinical resources and improve the efficiency of healthcare, it is often necessary to accurately locate patients and doctors in a healthcare facility. However, existing tracking methods, such as GPS, Wi-Fi and RFID, have technological drawbacks or impose significant costs, thus limiting their applications in many clinical environments, especially those with indoor...
This paper describes an ultra-wideband (UWB) transmitter architecture for secure proximity communication. The transmitter achieves high security by utilizing a pseudorandom scrambling method for both frequency hopping in frequency domain and pulse position modulation (PPM) in time domain. In addition, the low transmitted power of −70dBm/MHz not only makes it difficult for other receivers to detect...
This paper proposes an indoor positioning system based on the iBeacon framework. The proposed positioning scheme is a path loss method which uses the coordinate of transmitters in estimating the receiver's coordinate. To effectively reduce the measurement error due to reflected waves, we introduce a technique to represent the region at which the receiver is likely to exist by using the superposition...
In this paper we implement a turbo based Overlay Cognitive radio Z-channel with Trellis shaping, where the primary and cognitive users transmits and receives concurrently, utilizing the same spectrum. We ensure that bit error rate (BER) performance of the Primary does not degrade even in the presence of cognitive user. We derive bit error rate BER curves for both users, and show significant improvement...
In order to analyze the electromagnetic compatibility of communication system, a test method based on symbol error rate (SER) is proposed, then the experimental system was built. The influence of in-band electromagnetic interference on communication system was studied, and the mechanism was got. The results indicate that for the same frequency interference, the SER increase slowly in the front 2 dBm...
This paper presents the theoretical approach in developing the estimator equations for estimating distance and unknown channel parameters of indoor environment based on the received signal strength (RSS) method in Wireless Sensor Networks. The estimator equations are derived by manipulating the lognormal propagation model via maximum likelihood estimation method. In this paper, the path loss exponent...
Transmission over wireless channel is challenging. As such, different application required different signal processing approach of radio system. So, a highly reconfigurable radio system is on great demand as the traditional fixed and embedded radio system are not viable to cater the needs for frequently change requirements of wireless communication. A software defined radio or better known as an SDR,...
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