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Several regional augmentation GNSS systems (like SBAS) are already fully operational and other are under development with new frequencies and signals on the way. Therefore, it becomes imperative to guarantee for all GNSS users the compatibility, interoperability and interchangeability between all these systems. The goal is to ensure that the user's multi-mode receiver can choose and mix signals from...
The Factored Correlator Model (FCM) is an analytical model for the outputs of a GNSS receiver's correlators. The FCM precludes the need for simulation of the lower-level signal processing stages, significantly increasing simulation speed and considerably decreasing processing and memory requirements, while still keeping a high level of realism. Results for the FCM validation using statistical models...
Due to the large amount of different new applications based on GNSS systems, the issue of interference monitoring is becoming an increasing concern in the satellite navigation community. Threats for GNSS can be classified as unintentional interference, jamming and spoofing. Among them, spoofing is more deceitful because the target receiver might not be able to detect the attack and consequently generate...
Duty cycling is a common method to reduce the energy consumption in wireless sensor nodes. Since all the nodes turn on their radio in a time slot, but only few of them actually exchange messages, energy is wasted. This can be avoided by using a separate wake-up radio. We present a new approach for a wake-up receiver that consumes 2.78 μA of current and integrates a 16 bit address coding for a selective...
Generally, the extended Kalman filter (EKF) is used for sensor fusion in a land vehicle navigation system. However, defects of the first-order linearization of the nonlinear model in the EKF can introduce large estimated errors, and may lead to sub-optimal performance. In order to yield higher accuracy of navigation, in this paper, a novel particle filter (PF) for sensor fusion is proposed and the...
Linear and nonlinear receiver structures based on Minimum Mean Square Error (MMSE) linear combiner are proposed to mitigate the effect of multiuser interference in uplink Direct Sequence overloaded Code Division Multiple Access (DS-CDMA) system. The proposed mitigation algorithm exploits the inherent multi-path diversity and diminishes the effects of both Inter Symbol Interference (ISI) and Multiuser...
In this work, we consider a uni-directional (one way) relay network with a pair of primary transmitter and receiver which are relay-assisted by multiple cognitive radio (CR) terminals. A CR base station is deployed to sense the absence/presence of the primary user based on the received signal-to-noise ratio (SNR) at the fusion center. The primary network utilizes a two-step one-way amplify-and-forward...
Local oscillator is an important device for survival radio system receiver. In this paper, a simple design and flexible configuration, local oscillator using DDS (Direct Digital Frequency Synthesis) technology has been designed and realized. Concerning with double conversion superheterodyne RF Front-End for the receiver, the local oscillator is to generate two channel sinusoidal signals whose frequencies...
Multicasting is a challenging task that facilitates group communication among the nodes using the most efficient strategy to deliver the messages over each link of the network. In spite of significant research achievements in recent years, efficient and extendable multicast routing in Mobile Ad Hoc Networks (MANETs) is still a difficult issue. To enhance performance and to enable scalability we have...
Noncoherent receivers are the practical solutions for impulse radio (IR) ultra-wideband (UWB) systems due to their low-complexity and low-cost implementation. However, this simplicity is achieved at the expense of some performance degradation. In this paper, we propose the utilization of time reversal (TR) technique to improve the performance of a recently presented noncoherent detection scheme, called...
Detection oriented UWB wireless sensor node places several stringent requirements on compatibility, power consumption and implementation cost. The compatibility requirements mandate the digital realization by using high speed analog-to-digital converter (ADC). However, the need of full resolution, extremely high speed ADC contradict to the application demand of low cost and power consumption. Finite-resolution...
This paper proposes an improved implementation of the subspace projection method aiming to minimize the near-far effect that occurs in Global Navigation Satellite System receivers. Our technique does not demand phase estimation of the strong signals, thus being suitable for non-coherent receivers. Simulation results demonstrate the effectiveness and the limitations of the proposed mitigation technique.
This paper analyzes strengths and shortcomings of the existing aids for GNSS receiver development. A new set of tools is presented that provides to the developer debugging and optimization capabilities not supplied so far by existing tools. The proposed tools are simple and therefore very affordable, but never the less they are very functional. The first results are presented from the application...
Low intermediate frequency structure is applied to the receiving process and can solve the existing problems of receiver, such as large volume, high cost, poor expansibility and weak compatibility. On the basis of theoretical analysis and calculation, a kind of low intermediate frequency receiver is designed by using component which bought form market. Simulation is made by using ADS electronic design...
A new approach for the approximation of the channel log-likelihood ratio (LLR) for wireless channels based on Taylor series is proposed. The approximation is applied to the uncorrelated flat Rayleigh fading channel with unknown channel side information at the receiver. It is shown that the proposed approximation greatly simplifies the calculation of channel LLRs, and yet provides results almost identical...
In this paper we examine the use of generalized singular value decomposition (GSVD) for coordinated beamforming in MIMO systems. GSVD facilitates joint decomposition of a class of matrices arising inherently in source-to-2 destination MIMO broadcast scenarios. GSVD allows two channels of suitable dimensionality to be jointly diagonalized, i.e. to be reduced to non-interfering virtual broadcast channels,...
This paper describes a method to mitigate interference when the cyclic prefix (CP) is totally removed for shaped orthogonal frequency division multiplexing (OFDM) signals. The CP is removed to increase system throughput while shaping is applied to increase the spectral efficiency. Samples in the shaping extension are used to restore part of the cyclicity information missing in the ith received symbol...
A comprehensive study based on chip-package co-modeling compares the effects between flip-chip ball-grid-array (FC-BGA) and wire-bond quad-flat-nonlead (WB-QFN) packages on a front-end cascode low-noise amplifier (LNA) in a 2.45 GHz CMOS wireless local area network (WLAN) receiver. In practical applications, the established package models are used to predict the degradation of figure of merit (FOM)...
Multi-carrier code division multiple access (MC-CDMA)has been considered as a strong candidate for next generation wireless communication system due to its excellent performance in multi-path fading channel and simple receiver structure. However, like all the multi-carrier transmission technologies such as OFDM, the inter-carrier interference (ICI) produced by the frequency offset between the transmitter...
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