During the past decade, many wireless communication techniques have been developedto achievevariousgoals suchas higherdata rate,morerobustlink quality, and higher number of users in a given bandwidth. For wireless communication systems, depending on the availability of a feedback link, two approaches can be considered: namely open and closed loop. Open loop communication system that does not exploit the channel knowledge at the Transmitter is now well understood from both a theoretical and practical point of view.
標(biāo)簽： Communication Strategies Feedback Wireless for
上傳時間： 2020-05-27
上傳用戶：shancjb
OSCILLATORS are key building blocks in integrated transceivers. In wired and wireless communication terminals, the receiver front-end selects, amplifies and converts the desired high-frequency signal to baseband. At baseband the signal can then be converted into the digital domain for further data processing and demodula- tion. The Transmitter front-end converts an analog baseband signal to a suitable high- frequency signal that can be transmitted over the wired or wireless channel.
標(biāo)簽： High-Frequency Oscillator Design
上傳時間： 2020-05-27
上傳用戶：shancjb
In order to improve the spectral efficiency in wireless communications, multiple antennas are employed at both Transmitter and receiver sides, where the resulting system is referred to as the multiple-input multiple-output (MIMO) system. In MIMO systems, it is usually requiredto detect signals jointly as multiple signals are transmitted through multiple signal paths between the Transmitter and the receiver. This joint detection becomes the MIMO detection.
標(biāo)簽： Complexity Detection MIMO Low
上傳時間： 2020-05-27
上傳用戶：shancjb
Many wireless communications channels consist of multiple signal paths from the Transmitter to receiver. This multiplicity of paths leads to a phenomenon known as multipath fading. The multiple paths are caused by the presence of objects in the physical environment that, through the mechanisms of propagation, alter the path of radiated energy. These objects are referred to as scatterers. In the past, researchers often looked at ways to mitigate multipath scattering, such as in diversity systems. Multiple-input, multiple-output (MIMO) systems, on the other hand, use multipath diversity to their advantage; a MIMO system has the ability to translate increased spatial diversity into increased channel capacity.
標(biāo)簽： Multiple-Output Multiple-Input Channel Models
上傳時間： 2020-05-31
上傳用戶：shancjb
By inventing the wireless Transmitter or radio in 1897, the Italian physicist Tomaso Guglielmo Marconi added a new dimension to the world of communications. This enabled the transmission of the human voice through space without wires. For this epoch-making invention, this illustrious scientist was honored with the Nobel Prize for Physics in 1909. Even today, students of wireless or radio technology remember this distinguished physicist with reverence. A new era began in Radio Communications.
標(biāo)簽： Radio Frequency Modulation
上傳時間： 2020-06-01
上傳用戶：shancjb
A wireless communication network can be viewed as a collection of nodes, located in some domain, which can in turn be Transmitters or receivers (depending on the network considered, nodes may be mobile users, base stations in a cellular network, access points of a WiFi mesh etc.). At a given time, several nodes transmit simultaneously, each toward its own receiver. Each Transmitter–receiver pair requires its own wireless link. The signal received from the link Transmitter may be jammed by the signals received from the other Transmitters. Even in the simplest model where the signal power radiated from a point decays in an isotropic way with Euclidean distance, the geometry of the locations of the nodes plays a key role since it determines the signal to interference and noise ratio (SINR) at each receiver and hence the possibility of establishing simultaneously this collection of links at a given bit rate. The interference seen by a receiver is the sum of the signal powers received from all Transmitters, except its own Transmitter.
標(biāo)簽： Stochastic Geometry Networks Wireless Volume and II
上傳時間： 2020-06-01
上傳用戶：shancjb
Wavelength division multiplexing (WDM) refers to a multiplexing and transmission scheme in optical telecommunications fibers where different wavelengths, typically emitted by several lasers, are modulated independently (i.e., they carry independent information from the Transmitters to the receivers). These wavelengths are then multiplexed in the Transmitter by means of passive WDM filters, and likewise they are separated or demultiplexed in the receiver by means of the same filters or coherent detection that usually involves a tunable local oscillator (laser).
標(biāo)簽： Multiplexing Wavelength Division
上傳時間： 2020-06-01
上傳用戶：shancjb
Universival Asychronous Receiver/Transmitter（通用異步串行口），UART 是一種較為通用的數(shù)據(jù)傳輸?shù)姆椒ǎ碨tart Bit＋Data＋Check＋StopBit），而COM 口中Rx、Tx 的數(shù)據(jù)格式即為UART。UART 和RS232是兩種異步數(shù)據(jù)傳輸標(biāo)準(zhǔn).計算機(jī)中的COM1和COM2都是RS232串行通信標(biāo)準(zhǔn)接口。當(dāng)Uart 接口連到PC 機(jī)上時，需要接RS232電平轉(zhuǎn)換電路。
上傳時間： 2021-11-30
上傳用戶：
近距電能傳輸——高效安全近距電能傳輸一般基于電磁感應(yīng)原理進(jìn)行。在此技術(shù)基礎(chǔ)上，當(dāng)接收器鄰近發(fā)射器時才會進(jìn)行電能傳輸。電磁感應(yīng)技術(shù)的歷史長達(dá)百年，多年米一直應(yīng)用于各類電子產(chǎn)品中—如此普及全因其簡單、高效以及安全技術(shù)概覽以下將為你簡要介紹無線電能傳輸技術(shù)。System Overview(Communication)Receiver sends messagesTo provide control information to the TransmitterBy load modulation on the power signaTransmitter receives messagesTo receive control information frorn the recelverBy de-modulation of the reflected loadPower Pick Up( Receiver)Secondary coil (L Serial resonance capacitor (C) for efficient power transfer Parallel resonance capacitor(C, )for detection purposes Rectifier: full bridge(diode, or switched)+ capacitor Output switch for(dis)connecting the loadReceiver modulates load by Switching modulation resistor(R,n),or Switching modulation capacitor(Ca)Transmitter de-modulates reflected load by Sensing pnmary coil curent (p)and/o Sensing primary coil voltage (V,
上傳時間： 2022-03-31
上傳用戶：
基于TMS320F28335的超聲波流量計硬件原理圖+軟件源碼本文以TMS320F28335 處理器為核心，設(shè)計一種用于管道流量測量的超聲波流量計。系統(tǒng)硬件由核心板，超聲波發(fā)射和接收電路，切換電路，超聲換能器，基于ADS805 的高速信號采集電路，人機(jī)交互以及電源等模塊構(gòu)成。采用時差法進(jìn)行管道流量測量，時差測量采用SCOT 加權(quán)的廣義互相關(guān)時延估計算法。本論文設(shè)計的超聲波流量計具有測量速度快、準(zhǔn)確性好、成本低等優(yōu)點(diǎn)。關(guān)鍵字：C2000，超聲波，流量，廣義互相關(guān)算法AbstractA kind of ultrasonic flowmeter using for the pipe flow measurement is designed based onTMS320F28335 in this paper. The system hardware consists of the following parts: the core board,ultrasonic signal Transmitter and receiver circuits, switch circuit, ultrasonic transducer, signalacquisition circuit based on ADS805, human-computer interaction module and power supplymodule, etc. The system use the method of time difference for pipeline flow measurement and thetime difference is calculated by the time-delay algorithm of SCOT weighted generalizedcross-correlation. The ultrasonic flowmeter has the features of high testing speed, high precisionand low cost, etc.Keywords: C2000,Ultrasonic, Flow, Generalized Cross-Correlation Algorithm
標(biāo)簽： tms320f28335 超聲波流量計
上傳時間： 2022-05-06
上傳用戶：
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