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.
This paper investigates the network function virtualization (NFV)-enabled multicast problem, and proposes a steiner tree-based algorithm to reduce the cost of virtual network function (VNF) deployment and routing. In the algorithm, to minimize the bandwidth consumption, the Steiner tree is constructed by taking all the destination nodes as the terminals. Then a interconnection node of the tree is...
As one of the major radio-frequency impairments in multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system, in-phase and quadrature-phase (IQ) imbalance tends to destroy the reciprocity between uplink and downlink channel based on time-division duplex (TDD) mode and deteriorate system performance. In this paper, a time-domain calibration scheme is proposed to...
With the rapid development of 100Gbit/s technology and its increased commercial applications, various different type of 100G optical transceiver modules have been designed and widely used, which leads to the difficulties of achieving interconnection between 100G switch or router due to their different optical interfaces. On the other hand, in order to increase the port density of 100G switch or router,...
In this paper, massive MIMO measurements are carried out with a Massive MIMO testbed and a multi-antenna mobile terminal. The 8-antennas handset with a dimension of 15cm×7.5cm is used as the mobile station in order to mimic a smartphone. Measurements are successively undergone in a typical indoor scenario. The influence of antenna numbers in the handset on the indoor wireless channel characteristic...
Multiple controllers are connected to each other to construct a scalable SDN (Software Defined Network) control plane, and every switch is connected to a dedicated controller in data plane. The load on controllers changes dynamically in accordance to the services varying in switches; and switches need to be migrated from their master controllers to slave controllers to make the load balanced for SDN...
In this paper, we investigate the downlink of millimeter-wave multi-user massive MIMO systems, and propose a hybrid precoding scheme based on a sub-array architecture to achieve a better compromise between hardware cost and system performance. The proposed precoding scheme performs analog precoding and digital precoding at the transmitter with the generalized sub-array architecture. It implements...
Polar codes has a better bit error rate (BER) performance than low-density parity-check (LDPC) and turbo codes with lower coding and decoding complexity. The polar-coded cooperation can provide significant enhancement of data rate and link reliability. However, simply binary coded cooperation cannot meet the requirements of spectral efficiency. In order to improve the spectral efficiency, this paper...
This paper proposes a symmetric co-prime parallel array (S-CPPA) configuration for two-dimensional direction of arrival (2-D DOA) estimation. Specifically, the S-CPPA consists of a co-prime pair of symmetric uniform linear subarrays (ULAs). By vectorizing the cross-correlation matrix of the received signals, the sum and difference coarrays perspective is developed to obtain a large number of degrees...
Due to the power consumption and hardware implementation cost limitation, hybrid analog and digital precoding is a promising candidate for millimeter wave (mmWave) large-scale multiple-input multiple-output (MIMO) systems. Most of the prior work on hybrid beamforming considers frequency-flat channels. However, in practice, thanks to the large amount of available spectral resource, mmWave communication...
Under the target's sparse prior condition, the sparse signal recovery algorithm based on compressive sensing (CS) theory can improve the imaging resolution of the inverse synthetic aperture radar (ISAR) with limited observation samples. However, traditional sparse signal recovery algorithm has poor robustness under low SNR. In view of this problem, under the two-dimensional (2-D) ISAR signal model,...
In order to reduce the effect of pilot contamination and maximize the system sum rate while guaranteeing the fairness among users, an efficient and fair pilot allocation scheme is proposed for multi-cell massive MIMO systems in this work. The pilot allocation optimization problem is formulated to maximize the sum rate of the system while guaranteeing the fairness among users. A heuristic algorithm,...
Parameters estimation is a crucial and challenging component for Frequency-Hopping (FH) communication. Time-frequency analysis is a valid signal processing tool to estimate parameters of FH signal. However, the existing Time-Frequency analysis methods have several shortcomings such as weak suppression noise interference and feeble concentration of Time-Frequency, resulting in inaccurate parameter...
In this paper, we propose a three-parallel co-prime array (TPCPA) configuration for two-dimensional (2D) direction of arrival (DOA) estimation. TPCPA consists of three co-prime subarrays that have N, 2M and N sensors with inter-element spacing of N, M and N units respectively, where M and N are co-prime integers. Compared with the conventional parallel co-prime array (PCPA) and uniform linear arrays...
The recent spread of mobile networks has paved the way for building a pervasive social networking (PSN) environment, which enables people to access social networking services (SNS) anytime and from anywhere. There have been extensive studies on MANETs (Mobile Ad-hoc NETworks), which use mobile terminals for relaying information. While the feasibility of using them as emergency networks in the aftermath...
In this paper, we propose a systematic design approach of polar codes for multicolor visible light communication (VLC). Owing to the mixed ratio of multicolor light intensities and the interference between different colors, the channel polarization over a multicolor VLC system is markedly different from that over a uniform channel. Our scheme quantifies these different color channels and constructs...
In this paper, we improve the direction finding accuracy for shortwave fixed stations located in imperfect environment. A correction method of direction finding data is proposed based on least square algorithm. Firstly, we establish the mathematical model of the relationship between real azimuthal angles and errors according to the statistical features of direction finding data. Then we design model...
In this paper, we study the problem of secret key generation with one-way communication, where in addition to the rate limited public channel, which can be observed by both Bob and Eve, we add a secure channel, which only connects Alice and Bob. In this model, we do not pose any constraints on the sources, i.e. Bob is not degraded to or less noisy than Eve. We propose an achievability scheme, and...
In ultra-dense cellular networks, research works on enhancing cell edge performance receive considerable attention. Based on interlaced clustering, we propose a heuristic sparse beamforming strategy to improve the cell edge throughput effectively in distributed antenna systems (DASs). In our scheme, each cluster pattern (CP) is divided into several adaptive cells, where all the remote antenna units...
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.