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The spectrum sharing between radars and communication networks raises attention in recent years. Unlike communication, the radars usually occupy large extent of frequency bandwidth, and have different kinds of missions, which make the spectrum sharing problem more complicated. In this paper, we model the scenario that multiple imaging radars, which are the most common spectrum demanders, working in...
In this paper, we present a method for estimating the signal sources steering vector using an arbitrary planar array with omnidirectional elements. The proposed method improves the initial estimation of the signal steering vector in two steps. In the first step of this algorithm we minimize of the distance between the steering vector and the signal subspace. The second step improves the estimation...
Locally underutilized TV broadcasting spectrum is regarded as white space. Part of the TV frequency band, which is usually referred as 700MHz band, is excellent for radio communications due to its favorable radio propagation characteristic. This spectrum can be used to provide mobile broadband for the rural and mountainous areas effectively. Currently, this 700 MHz band is used exclusively for TV...
In modern electronic countermeasures, in order to interfere the normal work of reconnaissance receiver, the electronic jammer is usually used. For the wideband noise signal emitted by the jammer, the novel direction finding and localization algorithms are presented. In the direction finding(DF) algorithm, the time delay estimation is converted to the frequency estimation. The algorithm is not limited...
An improved algorithm is presented for speech enhancement via sparse representation and ideal binary mask (IBM) methods. In the traditional IBM, the basic idea is to identify voiced components as target signal and label unvoiced ones as interference noise vice versa. However, such voiced and unvoiced components still cannot be well separated in target signal and interference noise. To fully exploit...
A microphone array post-filter design effective in various noise environments is proposed for implementation in a hands-free speech interface. Although various post-filter designs have been studied, few methods have been effective in practical use since different types of sound sources, such as spatially coherent target/interference sources and incoherent background noise, are included in the observation...
Communication between LEO satellites and ground stations is in a complex channel environment, so it is a critical issue for the realization of that direct spread spectrum communication system for fast synchronization. Based on the characteristics of the LEO satellite channel, the paper proposes a selected automatic censoring excluding average (SACEA) method based on the automatic censoring cell average...
This paper addresses two majors problems in today's wireless network using MIMO-OFDM. In fact, the performances of such a network depend on the interference management and on the equalization. These two problems are closely linked to channel estimation algorithms. In this paper, we propose a resource sharing scenario combined with a blind channel estimation algorithm based on fourth order statistics...
Superposed multicarrier transmission scheme is known to improve frequency utilization efficiency when several wireless systems share the same spectrum. To suppress the effect of interference, forward error correction (FEC) metric masking is proposed. In the technique, log-likelihood ratio (LLR) that corresponds to superposed band is set to zero, because received bits that correspond to superposed...
In this work there were reviewed the issues of robustness of frequency estimation of harmonic signal mixed with additive Gaussian noise and chaotic impulse interference by the method of maximum likelihood. There were analyzed estimates obtained by both taking into account and excluding the likelihood function of interference parameters. It was investigated the influence of a priori information about...
We investigate cooperative radar and communications signaling. While each system typically considers the other system a source of interference, by considering the radar and communications operations to be a single joint system, the performance of both systems can, under certain conditions, be improved by the existence of the other. As an initial demonstration, we focus on the radar as relay scenario...
In this paper, we address the multiuser detection problem in the presence of strong interference, mixture of Gaussian and α-stable noises. We initially obtain locally optimal (LO) detection rule for this problem which can almost completely suppress interference effect and combat α-stable noise to some extent using oversampling in the receiver or channel coding in the transmitter. Then, we derive a...
This paper proposes distributed inter-cluster interference management procedures for 1 Coordinated Multi-Point (CoMP) Time Division Duplexing (TDD) cellular networks, in which a set of base stations (BSs), that form a cluster, cooperate in the downlink (DL) and uplink (UL) transmissions to communicate with a group of users while causing interference to users in neighbor clusters. In order to reduce...
This work addresses the problem of estimating the interference temperature in cognitive radio systems. The proposed technique exploits higher order moments of the received signal to achieve accurate estimation of the noise and signal power. Then, the noise power is used for the evaluation of the interference temperature. Performance analysis has been carried out in comparison with the conventional...
The Global Positioning System (GPS) with various commercial and military applications is designed to estimate the location of the specific user or object. It requires at least four satellites to accurately estimate the location. Since GPS signals suffer from various high power interference signals and jammers, we employ efficient interference suppression techniques such as a minimum-variance distortionless-response...
Electromagnetic compatibility (EMC) is the ability of a Radio communication Equipment (RCE) to operate with a desired quality of service in a given Electromagnetic Environment (EME) and not to create harmful interference with other RCE. This paper presents an algorithm which improves the simulation speed of estimating EMC of RCE in a complex EME, based on a stage by stage frequency-energy filtering...
In electronic countermeasures, in order to interfere the normal work of reconnaissance receiver, the noise signal emitted by the jammer is usually used for electromagnetic suppression. Otherwise, the radar signal may be exist in the reality electromagnetic environment. Signals can not be recognized in time domain because of the superposition of interference signal and radar signal. The directions...
In order to monitor the interference in GNSS, the bearings measurement of the interference source is needed. Because the high-order cumulant (HOC) is able to suppress Gaussian nose, a music algorithm based on the Interference Bearings Measurement 4-order cumulant of circle array GNSS is put forward. The MUSIC algorithm based on HOC can be used in GNSS Interference Bearings Measurement to decrease...
A new direction of arrival(DOA) estimator in the presence of interference is presented in this paper. To suppress interference, the oblique projection is constructed with the prior knowledge of interference sources, which is used to filter undesired signals out. After filtering, DOAs of signals are estimated by the improved L1-SVD algorithm, in which the noise power is estimated to solve the optimization...
This paper deals with a cognitive approach used to reduce the co-channel interference arising from the coexistence of an LTE macrocell and an LTE femtocell sharing the same frequency band. Multiple-antennas technology is considered to exploit the angle dimension as a new spectrum opportunity: femtocell acts as a secondary system and inserts nulls in the directions of the UE connected to the macrocell...
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