Read the abstract, see who wrote it and who cites it, and get the citation in APA, MLA, Chicago or Harvard.
About 721 papers for “macrocells”
Thambipillai Srikanthan, Damodaran Radhakrishnan, A.B. Premkumar · DR-NTU (Nanyang Technological University) · 2008
To investigate various techniques such as redundant arithemtic and residue number systems to produce large arithemtic functions in the form of VLSI macrocells capable of process independent reuse in systems incorporating standard on-chip bus sytems.
Cited by 0
Simon R. Saunders, Alejandro Aragón-Zavala · 2024
This chapter introduces methods for predicting the path loss encountered in systems where a high transmitter provides coverage to many locations over a wide area. The measurement-based prediction approach combines the relative simplicity of the semi-empirical methods commonly used in current planning tools with the added assurance of local measurements in producing predictions as close as possible to ‘reality’. The chapter presents comparison of the path loss predictions of most of the models. Broadcasting is typically used to describe the transmission of radio waves intended to reach a wide audience, in a sort of point-to-multipoint approach, usually for TV or radio services. Most broadcasting systems use digital technology. In macrocells, empirical models have been used with great success, but deterministic physical models are being increasingly applied as a means of improving accuracy, based on the use of multiple rooftop diffraction as the key propagation mechanism.
Cited by 0
R. Seetharaman, R. Vijayaragavan · International Journal of Computer Applications · 2012
Femtocells are intelligent cellular access points that support any mobile device using standard cellular air interfaces, such as UMTS, CDMA2000 and LTE. They contain cellular radios that are tightly integrated with the existing macrocell radio network and thus create a seamless experience for mobile users as they move in and out of femtocell coverage, whether on an active call or in standby. Femtocells learn their radio frequency (RF) surroundings and use this information to self-optimize their operation. In particular, femtocells use their RF awareness to control interference between themselves and between femtocells and macrocells. The surest way to increase the system capacity of a wireless link is by getting the transmitter and receiver closer to each other, which creates the dual benefits of higher quality links and more spatial reuse. In a network with nomadic users, this inevitably involves deploying more infrastructure, typically in the form of microcells, hotspots, distributed antennas, or relays In this paper contains the technical view for femtocells, and describe the state-of-the-art on each front. Also describe the technical challenges facing femtocell networks, and give some preliminary ideas for how to overcome them.
Cited by 0Open access
Gao, Zhimin · Library and Archives Canada (Government of Canada) · 1999
Cited by 0
Orlando Arias, Dean Sullivan, Haoqi Shan et al. · 2020
In recent years, we have seen an advent in software attestation defenses targeting embedded systems which aim to detect tampering with a device's running program. With a persistent threat of an increasingly powerful attacker with physical access to the device, attestation approaches have become more rooted into the device's hardware with some approaches even changing the underlying microarchitecture. These drastic changes to the hardware make the proposed defenses hard to apply to new systems. In this paper, we present and evaluate LAHEL as the means to study the implementation and pitfalls of a hardware-based attestation mechanism. We limit LAHEL to utilize existing technologies without demanding any hardware changes. We implement LAHEL as a hardware IP core which interfaces with the CoreSight Debug Architecture available in modern ARM cores. We show how LAHEL can be integrated to system on chip designs allowing for microcontroller vendors to easily add our defense into their products. We present and test our prototype on a Zynq-7000 SoC, evaluating the security of LAHEL against powerful time-of-check-time-of-use (TOCTOU) attacks, while demonstrating improved performance over existing attestation schemes.
Cited by 6
Luca Benini, Luca Macchiarulo, Enrico Macii · 2001
Abstract. PTL represents a viable alternative to standard CMOS for the implementation of specific units in performance-constrained systems. Unfortunately, this design style has not found wide acceptance in the designers ’ community, due to the lack of an established flow for automatic synthesis. In this paper, we present a procedure for constructing area and timing models for PTL macrocells. This is an key step towards the definition of a complete PTL design flow that is currently being pursued. 1
Cited by 0
B. Korte, Hans Jürgen Prömel, Angelika Steger · 2002
The authors report on a design system for the physical layout of ASIC's with macrocells, which has been developed during the last three years in the framework of a research contact with IBM Germany and used successfully in practice. The main idea is to apply a hierarchical placement procedure together with global routing and timing analysis. This technique enables one to guarantee at each step of the placement the routability of the chip as well as the desired timing. The authors sketch some ideas of the design system roughly and report on some practical experience.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Cited by 0
Seokhyun Yoon, Joonyoung Cho · IEICE Transactions on Communications · 2012
The impact of co-channel deployment of femtocells on existing macro-cellular systems is investigated considering the use of techniques to resolve the loud neighbor problem. There are several approaches to this aim, for example, femtocell power control, interference coordination, and opening access to femtocells. Of these, coordinated scheduling, including power control, and their impact will be the main focus of this work. In the context of 3GPP-LTE, we examine under various operational scenarios the performance in terms of the average and 5% worst user throughput, a useful measure of fairness among users, both for femto and macro cells. Although recent studies have shown that co-channel femtocell has a minor impact on the macrocell performance in average sense, a non-negligible percentage of users may lose their opportunity to get satisfactory data service and, hence, we focus more on the 5% worst users.
Cited by 1
U. Martin · IEE Proceedings - Radar Sonar and Navigation · 1998
The performance assessment of new mobile radio base station (BS) transceiver concepts with adaptive intelligent antennas requires realistic directional radio channel models. An appropriate model is derived from the results of an extensive uplink sounding campaign performed at 1.9 GHz in a urban macrocell within the City of Frankfurt. In the experiments the wideband sounder RUSK XL was applied for synthetic aperture reception. The directional multipath propagation is characterised by means of delays, directions of arrival (DOA) at the BS antenna array and mean powers of the multipath components. The coupled delay–DOA–power information is determined by an adaptation of the 2-D unitary ESPRIT algorithm. It can be used directly to configure fading simulators for multiple antenna reception which reflect real-world small-area radio channel properties in simulations at the link level. Additionally, probability distribution functions for excess delays, DOAs and mean powers are derived from the measurement results. They are useful for consideration of directional propagation effects in investigations of the cellular system behaviour.
Cited by 85
Ying‐Dar Lin, Hsu-Tung Chien, Hsien-Wen Chang et al. · IEEE Wireless Communications · 2017
To cope with the growth of mobile data traffic in 5G systems, telecom operators have to set up more small cells and macrocells in the same area. However, because of space limitations, it is difficult for each operator to do so, and RAN sharing would thus become mandatory for 5G systems. In this work, RANP is proposed, which will achieve transparent RAN sharing by setting up RANP between a base station to be shared and multiple core networks. Over and above the general one-level proxy architecture, an extended two-level architecture is proposed that will share both small cells and macrocells. According to our emulation results, additional packet processing time of a RANP is about 2 ms, 3.8 percent of the total end-to-end latency. Its impact on throughput is about 3 percent and can be regarded as irrelevant.
Cited by 27
Gaute Lambertsen, L. Zhang, Tomoaki Yamada · 2004
This paper presents a logical macrocell configuration in a microcellular network in which the capacity is larger than a conventional macrocellular network. And the network provides high-bit-rate communications to fast-terminals with smooth soft-handover. The application used in the network is mobile multimedia metropolitan area network (MM-MAN) which offers high-bit-rate IP communications for high-mobility terminals in metropolitan areas. We present a combination of wireless and wired network technologies to implement MM-MAN. Secure virtual private network (VPN) tunnel and seamless continuous services in microcellular network are basic requirements of MM-MAN. Passive optical network (PON) is adopted as the access network to support a great deal of optical network units (ONU) which controls each microcell. To reduce packet loss of high-mobility terminal caused by frequent handovers in the microcells, we configure logical macrocell (LMC). The LMC also makes use of IP packet multicast to support micromobility of the VPN tunnels. Through replacing the traditional macrocells with both microcells and LMC's which aims at fast-moving terminals, we increase the available spectral capacity which can be used to provide up to 80 times increase in bandwidth compared to macrocells, even if 30 % of the users are fast movers.
Cited by 8
Jiing-Yuan Lin, Wen-Zen Shen, Jing-Yang Jou · IEEE Transactions on Very Large Scale Integration (VLSI) Systems · 1999
To characterize the power consumption of a macrocell, a general method involves recording the power consumption of all possible input transition events in the look-up tables. However, though this approach is accurate, the size of the table becomes very large. In this paper, we propose a new power modeling technique that takes advantage of the structural information of a macrocell. In this approach, a subset of primary inputs and internal nodes in the macrocell are selected as the state variables to build a state transition graph (STG). These state variables can model the steady-state transitions completely. Moreover, by selecting the characterization patterns properly, the STG can also model the glitch power in the macrocell accurately. To further simplify the complexity of the STG, an incomplete power modeling technique is presented. Without losing much accuracy, the property of compatible patterns is exploited for a macrocell to further reduce the number of edges in the corresponding STG. Experimental results show that our modeling techniques can provide SPICE-like accuracy, while the size of the look-up table is significantly reduced.
Cited by 4
Peter Kraus, D.A. Mlynski · 1991
A new approach is presented for macrocell placement using an analogy with annealing in solids as the framework for optimization. The proposed method is an iterative improvement scheme which generates a chain of configurations from an initial configuration obtained by force-directed relaxation. It has the ability to avoid being trapped in a local minimum. All geometrical aspects such as shape, size and orientation of the circuit modules are considered simultaneously in each iteration step. Two benchmark examples with 10 and 33 blocks respectively are given to demonstrate the performance of the strategy.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Cited by 0
Zhong Xiu, Rob A. Rutenbar · 2007
Grid-warping is a placement strategy based on a novel physical analogy: rather than move the gates to optimize their location, it elastically deforms a model of the 2-D chip surface on which the gates have been coarsely placed via a standard quadratic solve. Although the original warping idea works well for cell-based placement, it works poorly for mixed-size placements with large, fixed macrocells. The new problem is how to avoid elastically deforming gates into illegal overlaps with these background objects. We develop a new lightweight mechanism called "geometric hashing" which relocates gates to avoid these overlaps, but is efficient enough to embed directly in the nonlinear warping optimization. Results from a new placer (WARP3) running on the ISPD 2005 benchmark suite show both good quality and scalability.
Cited by 7
Somnath Roy Choudhury, Sambhu Nath Pradhan · IEEE Access · 2019
This work presents a unique time-efficient and reliable floorplan algorithm DOTFloor (Diffusion Oriented Time-improved Floorplanner), built around a SA (Simulated Annealing) engine and targeted to optimize the peak on-chip temperature along with the traditional design metrics like chip area and wire length. This paper also proposes a novel heat-diffusion based stochastic thermal model called the FATT (Fast Assumption Technique for Temperature) which provides a fast assumption of the degree of hotness during the optimization process. The incorporation of FATT in DOTFloor results in a significant improvement in the run time of the optimization process. Upon experimentation on MCNC (Microelectronics Center of North Carolina) benchmark circuits with the proposed floorplanner, a good optimization in area, wire length metric and peak on-chip temperature with a significant reduction in execution time have been achieved over the existing floorplanning tool, the HotFloorplan.
Cited by 6Open access
Jean-Marc Conrat, Patrice Pajusco · HAL (Le Centre pour la Communication Scientifique Directe) · 2007
International audience
Cited by 1Open access
P.K. Sancheti, Sachin S. Sapatnekar · IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems · 1996
The problem of designing individual macrocells for a library for low power and high speed is addressed here, and a new technique for optimization using posynomial approximating functions is devised. In the design of each macrocell, optimality in design is critical and highly accurate techniques for measuring the performance are required during optimization. This paper presents methods for accurately estimating the worst-case contribution of the power and delay of a cell to a circuit. The program uses circuit-level simulation to calculate the power dissipation and delay of the cell with the highest accuracy. A rationale for using arbitrary degree posynomial modeling functions for area, delay, and power modeling is presented. The problem is then formulated as a convex programming problem, and a rigorous optimization technique is used to arrive at the optimal macrocell.
Cited by 7
Illa Kolani, Jie Zhang · 2012
MIMO and space-time coding (STC) as signal processing form a system which highly leads to perform the reliability and the capacity of the link of communications. This is achievable if the channel state information (CST) is perfectly known at the transceiver. Often the transceiver is not able to acquire the instantaneous knowledge of the channel state. Yet it can have a partial knowledge or estimation, typically the statistical distribution of the channel. In this paper we present the multi ring scattering channel for wireless communications. The channel is estimated by averaging over multiple ring scattering channels within a cell. As application an analysis of the performance orthogonal space-time block code (OSTBC) is simulated over the channel. It is shown that the performance can significantly reach that of uncorrelated channel.
Cited by 1
Qiaoyang Ye, Mazin Al‐Shalash, Constantine Caramanis et al. · arXiv (Cornell University) · 2013
The rate distribution in heterogeneous networks (HetNets) greatly benefits from load balancing, by which mobile users are pushed onto lightly-loaded small cells despite the resulting loss in SINR. This offloading can be made more aggressive and robust if the macrocells leave a fraction of time/frequency resource blank, which reduces the interference to the offloaded users. We investigate the joint optimization of this technique - referred to in 3GPP as enhanced intercell interference coordination (eICIC) via almost blank subframes (ABSs) - with offloading in this paper. Although the joint cell association and blank resource (BR) problem is nominally combinatorial, by allowing users to associate with multiple base stations (BSs), the problem becomes convex, and upper bounds the performance versus a binary association. We show both theoretically and through simulation that the optimal solution of the relaxed problem still results in an association that is mostly binary. The optimal association differs significantly when the macrocell is on or off; in particular the offloading can be much more aggressive when the resource is left blank by macro BSs. Further, we observe that jointly optimizing the offloading with BR is important. The rate gain for cell edge users (the worst 3-10%) is very large - on the order of 5-10x - versus a naive association strategy without macrocell blanking.
Cited by 32Open access
Francesco Curatelli · Integration · 1991
Cited by 6