The combinatorial core of the OVSF code assignment problem that arises in UMTS is to assign some nodes of a complete binary tree of height h (the code tree) to n simultaneous connections, such that no two assigned nodes (codes) are on the same root-to-leaf path. Each connection requires a code on a specified level. The code can change over time as long as it is still on the same level. We consider the one-step code assignment problem: Given an assignment, move the minimum number of codes to serve a new request. Minn and Siu proposed the so-called DCAalgorithm to solve the problem optimally. We show that DCA does not always return an optimal solution, and that the problem is NP-hard. We give an exact nO(h)-time algorithm, and a polynomial time greedy algorithm that achieves approximation ratio Θ(h). Finally, we consider the online code assignment problem for which we derive several results
标签： combinatorial assignment problem arises
上传时间： 2014-01-19
上传用户：BIBI
with this rar file i am sending five source codes in vhdl for xor gate,xor gate using tristae gate,electronic voting machine,mod 16 counter,jk flip flop.please accept these codes and make me member of this site.so that i can download code from this site also.i really needed codes please accept that as soon as possible.
上传时间： 2013-12-18
上传用户：wcl168881111111
KaOS is a real-time operating system that has been implemented with the basic real-time constraints and it supports dynamic memory module accessing of sd/mmc cards
标签： real-time constraints implemented operating
上传时间： 2013-12-31
上传用户：cuibaigao
KaOS is a real-time operating system that has been implemented with the basic real-time constraints and it supports dynamic memory module accessing of sd/mmc cards
标签： real-time constraints implemented operating
上传时间： 2017-05-24
上传用户：330402686
This book gives a comprehensive overview of the technologies for the advances of mobile radio access networks. The topics covered include linear transmitters, superconducting filters and cryogenic radio frequency (RF) front head, radio over fiber, software radio base stations, mobile terminal positioning, high speed downlink packet access (HSDPA), multiple antenna systems such as smart antennas and multiple input and multiple output (MIMO) systems, orthogonal frequency division multiplexing (OFDM) systems, IP-based radio access networks (RAN), autonomic networks, and ubiquitous networks.
标签： Advances Networks Access Mobile Radio in
上传时间： 2020-05-26
上传用户：shancjb
Over the past few decades, wireless communications and networking have witnessed an unprecedented growth, and have become pervasive much sooner than anyone could have predicted. For example, cellular wireless networks are expected to become the dominant and ubiquitous telecommunication means in the next few decades. The widespread success of cellular and WLAN systems prompts the development of advanced wireless systems to provide access to information services beyond voice such as telecommuting, video conferencing, interactive media, real-time internet gaming, and so on, anytime and anywhere.
标签： Compressive Networks Wireless Sensing for
上传时间： 2020-05-27
上传用户：shancjb
MIMO-OFDM is a key technology for next-generation cellular communications (3GPP-LTE, Mobile WiMAX, IMT-Advanced) as well as wireless LAN (IEEE 802.11a, IEEE 802.11n), wireless PAN (MB-OFDM), and broadcasting (DAB, DVB, DMB). This book provides a comprehensive introduction to the basic theory and practice of wireless channel modeling, OFDM, and MIMO, with MATLAB ? programs to simulate the underlying techniques on MIMO-OFDMsystems.Thisbookisprimarilydesignedforengineersandresearcherswhoare interested in learning various MIMO-OFDM techniques and applying them to wireless communications.
标签： Communications MIMO-OFDM Wireless MATLAB with
上传时间： 2020-05-28
上传用户：shancjb
The family of recent wireless standards included the optional employment of MIMO tyechniques. This was motivated by the observation according to the classic Shannon-Hartley law the achiev- able channel capacity increases logarithmically with the transmit power. By contrast, the MIMO capacity increases linearly with the number of transmit antennas, provided that the number of receive antennas is equal to the number of transmit antennas.
标签： Multi-Functional Near-Capacity Systems MIMO
上传时间： 2020-05-31
上传用户：shancjb
Before delving into the details of orthogonal frequency division multiplexing (OFDM), relevant background material must be presented first. The purpose of this chapter is to provide the necessary building blocks for the development of OFDM principles. Included in this chapter are reviews of stochastic and random process, discrete-time signals and systems, and the Discrete Fourier Transform (DFT). Tooled with the necessary mathematical foundation, we proceed with an overview of digital communication systems and OFDM communication systems. We conclude the chapter with summaries of the OFDM wireless LAN standards currently in existence and a high-level comparison of single carrier systems versus OFDM.
上传时间： 2020-05-31
上传用户：shancjb
Microengineering and Microelectromechanical systems (MEMS) have very few watertight definitions regarding their subjects and technologies. Microengineering can be described as the techniques, technologies, and practices involved in the realization of structures and devices with dimensions on the order of micrometers. MEMS often refer to mechanical devices with dimensions on the order of micrometers fabricated using techniques originating in the integrated circuit (IC) industry, with emphasis on silicon-based structures and integrated microelectronic circuitry. However, the term is now used to refer to a much wider range of microengineered devices and technologies.
标签： Microengineering Interfacing MEMS and
上传时间： 2020-06-06
上传用户：shancjb
