The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Using the minimum number of broadcasts to flood information in a vehicle network so that the maximum number of vehicles receives the information is a critical issue. Up to now, no research reports show the relationship between broadcast radius and success rate, the one-hop broadcast efficiency (i.e., the ratio of nodes that successfully received nodes to all nodes within the broadcast range). Determining...
In this paper, we address the direction-of-arrival (DOA) estimation problem of hybrid completely polarized (CP) and partially polarized (PP) source signals with arbitrary polarimetric arrays. Firstly, oblique projection filtering operators, which are insensitive to the state of polarization of signals, are used to separate potential source signals in the spatial domain. Secondly, the DOA estimates...
In recent years, accidents occur frequently because the people number of scenic spots is lack of control. In this paper, a novel real-time people number detection algorithm of scenic spot based on density center clustering (DPBC) is proposed. Taking account of the complexity of the scenic environment, we use the Gauss mixture model (GMM) to suppress the background interference, extract the feature...
This paper proposes a channel estimation algorithm for the High Speed Uplink Packet Access (HSUPA) system supporting the 64-QAM modulation and operating in a high Signal-to-Interference and Noise Ratio (SINR) regime. The algorithm is aimed to overcome limitations of the conventional approach which is based on simple correlation of the received signal with the pilot sequence and has insufficient performance...
The algorithm of reception signals with orthogonal frequency multiplexing (OFDM) in channels with dispersion is considered. The offered algorithm is based on processing "in general" on an interval of dispersion of sequence of counting of the bending-around symbol OFDM for the purpose receiving estimates of maximum likelihood of this sequence with the subsequent formation solutions of rather...
This paper addresses the problem of estimating the Multi-User Multiple Input Multiple Output (MU-MIMO) Channel Quality Indicator (CQI) from the reported Single-User MIMO rank-1 CQI. A hybrid MU-MIMO CQI estimation algorithm is proposed. Proposed algorithm applies a fixed back off offset to compensate the power sharing among co-scheduled users and a dynamic offset for Multi-User (MU) interference....
This paper considers distributed approaches for the downlink of multi-user MIMO interference network where all nodes iteratively and distributedly update their precoders or receive filters. Those include the distributed interference alignment and minimum sum mean-squared error schemes. We analyse these algorithms in presence of effective imperfect channel estimation at each iteration and we present...
The existing works on analyzing/utilizing spectrum whitespace in Cognitive Radio Networks (CRNs) are either empirical studies lacking of theoretical guarantee, or local primary network information based inducing inaccurate analysis and estimation, or overlooking the spectrum whitespace details. Therefore, we propose to systematically analyze the spectrum whitespace in CRNs from a social network perspective...
Filterbank multi-carrier with offset quadrature amplitude modulation (FBMC/OQAM) avoids the usage of the cyclic prefix (CP) by using more localized prototype filters. However, channel estimation in highly frequency selective channels is very challenging, especially for the scattered pilots due to the intrinsic interference leaked from the neighboring symbols. This paper presents a novel pilot design...
Conventional channel estimation algorithms devised for OFDM systems suffer from significant performance degradation in the presence of interference. This paper develops a robust least square (LS) channel estimation scheme with low complexity. The received pilot symbols are first separated into several groups, then each group is divided into two parts. After that, we apply the conventional LS algorithm...
Location sensing of physical objects is critical in many applications. Passive UHF Far-Field Radio Frequency Identification (RFID) technique provides an efficient solution due to its cost efficiency and simple identification procedure. In this paper we study the localization problem using passive UHF RFID systems under multi-reader and antenna conditions. We discuss practical characteristics of a...
This article considers the two-way bidirectional relaying scenario, in which it is crucial to improve the transmission efficiency to make up for the extra hop in the communication. Single-antenna two-way relaying can be implemented through a Self-Interference (SI) cancellation scheme known as Bidirectional Amplification of Throughput (BAT). This paper analyzes the impact that an imperfect cancellation...
RFID has been gaining popularity due to its variety of applications, such as inventory control and localization. One important issue in RFID system is tag identification. In RFID systems, the tag randomly selects a slot to send a Random Number (RN16) packet to contend for identification. Collision happens when multiple tags select the same slot, which makes the RN packet undecodable and thus reduces...
LS-EM algorithm can estimate Gaussian mixture autoregressive model (GMAR) parameter, which is one of the most efficient models for fitting PDF/PSD of non-Gaussian colored processes, especially interference background of detections. But its operation amount is too huge to be applied in real time. A modified LS-EM algorithm (MLS-EM) is proposed, which aborts the unnecessary feedback and coupling link...
In this paper we consider a centralized cross-layer splitting algorithm of a multi-packet reception slotted ALOHA system for contention resolution. In the algorithm, a base station estimates the number of backlogged mobile terminals by using a first-order auto-regressive (AR) model based on the number of packets successfully transmitted over previous contention resolution intervals (CRIs). Estimation...
To be sure that the telecommunication satellite can work well in the complexity electromagnetic environment and electromagnetic jamming, a novel space-borne antenna multi-jamming direction finding and nulling method is presented in the paper. Firstly, single-snapshot DOA estimation algorithm in frequency is presented to estimate the DOAs of multiple interferences, and then nulling algorithm that keep...
The performance of an adaptive interference canceller (AIC) is sensitive to the dasiasignal crosstalkpsila in the reference channel. This paper analyzes the performance of the crosstalk-resistant AIC at first. The transmitting function of the channel of the signal crosstalk in the cosite interference can be estimated approximately, so an additive channel is added at the input of the reference signal...
Ranging process in IEEE 802.16 system provides a number of functionalities such as initial network entry, uplink synchronization, power adjustment, and system coordination. As the introduction of relay network in IEEE 802.16 systems, a new transmission power control algorithm is necessary. Therefore, this paper proposes a novel ranging transmission power control algorithm which reduces the interference...
In this paper, an energy efficient adaptive modulation scheme is proposed for a wireless cognitive radio ad hoc network, where each node is equipped with cognitive radio and the network is an OFDMA system operating on time slots. In each slot, the users with new traffic demand will sense the spectrum and locate the available subcarrier set. Then they choose subcarriers with favorable channel condition...
The multi-access scheme of 802.11 wireless networks imposes difficulties in achieving predictable service quality in multi-hop networks. In such networks, the residual capacity of wireless links should be estimated for resource allocation services such as flow admission control. In this paper, we propose an accurate and non-intrusive method to estimate the residual bandwidth of an 802.11 link. Inputs...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.