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The investigation of the propagation channel is becoming more and more important in mod-
ern wireless communication. The demand for spectral efficiency motivates exploitation of
all channels that can possibly be used for communications. Nowadays, a common trend for
designing physical layer algorithms is to adapt the transceiving strategy, either by maximizing
the diversity gains or by utilizing the coherence of the channels to improve the signal-to-noise
power ratio.
標簽:
Characterization
propagation
Channel
上傳時間:
2020-05-31
上傳用戶:shancjb
-
Wireless means different things to different people. For this book, it refers
to the radio systems that provide point-to-point, point-to-multipoint, and
Earth-space communications over transmission links that propagate outside
buildings through the lower atmosphere. Wireless systems are being built
that provide data transmission between computers and other devices on
one’s own desk. These are part of the wireless world but not the part where,
except for interference perhaps, the atmosphere has any influence. The intent
of this book is to provide a description of the physical phenomena that can
affect propagation through the atmosphere, present sample measurements
and statistics, and provide models that system designers can use to calculate
their link budgets and estimate the limitations the atmosphere may place on
their design.
標簽:
Communication
propagation
Handbook
Wireless
for
上傳時間:
2020-05-31
上傳用戶:shancjb
-
This edition updates and continues the series of books based on the residential
courses on radiowave propagation organised by the IEE/IET.
The first course was held in 1974, with lectures by H. Page, P. Matthews,
D. Parsons, M.W. Gough, P.A. Watson, E. Hickin, T. Pratt, P. Knight, T.B. Jones,
P.A. Bradley, B. Burgess and H. Rishbeth.
標簽:
propagation
Radiowaves
edition
3rd
of
上傳時間:
2020-05-31
上傳用戶:shancjb
-
Radio propagation measurements and channel modelling continue to be of fundamental importance
to radio system design. As new technology enables dynamic spectrum access and higher data rates,
radio propagation effects such as shadowing, the presence of multipath and frequency dispersion
are the limiting factors in the design of wireless communication systems. While there are several
books covering the topic of radio propagation in various frequency bands, there appears to be no
books on radio propagation measurements, which this book addresses at length.
標簽:
propagation
Measurement
Radio
上傳時間:
2020-06-01
上傳用戶:shancjb
-
One of the prerequisites for the development of telecommunication services is the
understanding of the propagation of the waves, either acoustic, electromagnetic,
radio or light waves, which are used for the transmission of information.
In this work, we shall limit ourselves to the study of radio waves: this term
apply to the electromagnetic waves used in radio communications. Their
frequency spectrum is very broad, and is divided into the following frequency
bands : ELF waves (f < 3 kHz), VLF (3-30 kHz), LF waves (30-300 kHz), MF
waves (300-3000 kHz), HF (3-30 MHz), VHF waves (30-300 MHz), UHF waves
(300-3000 MHz), SHF waves (3-30 GHz), EHF waves (30-300 GHz) and sub-
EHF waves (300-3000 GHz).
標簽:
propagation
Radio
Wave
上傳時間:
2020-06-01
上傳用戶:shancjb
-
The MAX17600–MAX17605 devices are high-speedMOSFET drivers capable of sinking /sourcing 4A peakcurrents. The devices have various inverting and noninvertingpart options that provide greater flexibility incontrolling the MOSFET. The devices have internal logiccircuitry that prevents shoot-through during output-statchanges. The logic inputs are protected against voltagespikes up to +14V, regardless of VDD voltage. propagationdelay time is minimized and matched between the dualchannels. The devices have very fast switching time,combined with short propagation delays (12ns typ),making them ideal for high-frequency circuits. Thedevices operate from a +4V to +14V single powersupply and typically consume 1mA of supply current.The MAX17600/MAX17601 have standard TTLinput logic levels, while the MAX17603 /MAX17604/MAX17605 have CMOS-like high-noise margin (HNM)input logic levels. The MAX17600/MAX17603 are dualinverting input drivers, the MAX17601/MAX17604 aredual noninverting input drivers, and the MAX17602 /MAX17605 devices have one noninverting and oneinverting input. These devices are provided with enablepins (ENA, ENB) for better control of driver operation.
標簽:
17600
MAX
數據資料
上傳時間:
2013-12-20
上傳用戶:zhangxin
-
The PCA9549 provides eight bits of high speed TTL-compatible bus switching controlledby the I2C-bus. The low ON-state resistance of the switch allows connections to be madewith minimal propagation delay. Any individual A to B channel or combination of channelscan be selected via the I2C-bus, determined by the contents of the programmable Controlregister. When the I2C-bus bit is HIGH (logic 1), the switch is on and data can flow fromPort A to Port B, or vice versa. When the I2C-bus bit is LOW (logic 0), the switch is open,creating a high-impedance state between the two ports, which stops the data flow.An active LOW reset input (RESET) allows the PCA9549 to recover from a situationwhere the I2C-bus is stuck in a LOW state. Pulling the RESET pin LOW resets the I2C-busstate machine and causes all the bits to be open, as does the internal power-on resetfunction.
標簽:
switch
Octal
9549
with
上傳時間:
2014-11-22
上傳用戶:xcy122677
-
This a Bayesian ICA algorithm for the linear instantaneous mixing model with additive Gaussian noise [1]. The inference problem is solved by ML-II, i.e. the sources are found by integration over the source posterior and the noise covariance and mixing matrix are found by maximization of the marginal likelihood [1]. The sufficient statistics are estimated by either variational mean field theory with the linear response correction or by adaptive TAP mean field theory [2,3]. The mean field equations are solved by a belief propagation method [4] or sequential iteration. The computational complexity is N M^3, where N is the number of time samples and M the number of sources.
標簽:
instantaneous
algorithm
Bayesian
Gaussian
上傳時間:
2013-12-19
上傳用戶:jjj0202
-
bp神經網絡算法是解決最優化問題的先進算法之一,本論文討論了神經網絡中使用最為廣泛的前饋神經網絡。其網絡權值學習算法中影響最大的就是誤差反向傳播算法(back-propagation簡稱BP算法)。BP算法存在局部極小點,收斂速度慢等缺點。基于優化理論的Levenberg-Marquardt算法忽略了二階項。該文討論當誤差不為零或者不為線性函數即二階項S(W)不能忽略時的Hesse矩陣的近似計算,進而訓練網絡。
標簽:
神經網絡算法
算法
上傳時間:
2015-12-31
上傳用戶:wendy15
-
CLAWPACK is a software package designed to compute numerical solutions to hyperbolic partial differential equations using a wave propagation approach
標簽:
hyperbolic
numerical
solutions
CLAWPACK
上傳時間:
2014-01-03
上傳用戶:woshini123456