Use of multiple antennas at both ends of wireless links is the result of the natural progression of more than four decades of evolution of adaptive antenna technology. Recent advances have demonstrated that multiple- input-multiple-output (MIMO) wireless systems can achieve impressive increases in overall system performance.
標簽： Technology System MIMO
上傳時間： 2020-05-28
上傳用戶：shancjb
When we started thinking about writing this book, we had been working together for more than five years on the borderline between propagation and signal processing.Therefore, it is not surprising that this book deals with propagation models and design tools for MIMO wirelesscommunications.Yet, thisbookshouldconstitutemorethanasimplecombination of these two domains. It hopefully conveys our integrated understanding of MIMO, which results from endless controversial discussions on various multi-antenna related issues, as well as various interactions with numerous colleagues. Obviously, this area of technology is so large that it was beyond our aim to cover all aspects in details. Rather, our goal has been to provide researchers, R&D engineers and graduate students with a comprehensive coverage of radio propagation models and space–time coding techniques.
標簽： Communications5 Wireless MIMO
上傳時間： 2020-05-28
上傳用戶：shancjb
An acronym for Multiple-In, Multiple-Out, MIMO communication sends the same data as several signals simultaneously through multiple antennas, while still utilizing a single radio channel. This is a form of antenna diversity, which uses multiple antennas to improve signal quality and strength of an RF link. The data is split into multiple data streams at the transmission point and recombined on the receive side by another MIMO radio configured with the same number of antennas. The receiver is designed to take into account the slight time difference between receptions of each signal, any additional noise or interference, and even lost signals.
標簽： Understanding_the_Basics_of_MIMO
上傳時間： 2020-06-01
上傳用戶：shancjb
The explosion in demand for wireless services experienced over the past 20 years has put significant pressure on system designers to increase the capacity of the systems being deployed. While the spectral resource is very scarce and practically exhausted, the biggest possibilities are predicted to be in the areas of spectral reuse by unlicensed users or in exploiting the spatial dimension of the wireless channels. The former approach is now under intense development and is known as the cogni- tive radio approach (Haykin 2005).
標簽： Multi-Antenna Wireless Channels Modeling
上傳時間： 2020-06-01
上傳用戶：shancjb
In modern societies, the production and trade of goods all around the world is constantly increasing. The latest technological achievements allow the mass-production of millions of items of every kind, which are being exchanged all around the globe with unprecedented rapidity. At the same time, the problem of identifying, classifying and tracking such a growing multitude of objects is con- sequently arising.
標簽： soltions Antenna design RFID tags for
上傳時間： 2020-06-08
上傳用戶：shancjb
We are in the era of ubiquitous computing in which the use and development of Radio Frequency Iden- tification (RFID) is becoming more widespread. RFID systems have three main components: readers, tags, and database. An RFID tag is composed of a small microchip, limited logical functionality, and an antenna. Most common tags are passive and harvest energy from a nearby RFID reader. This energy is used both to energize the chip and send the answer back to the reader request. The tag provides a unique identifier (or an anonymized version of that), which allows the unequivocal identification of the tag holder (i.e. person, animal, or items).
上傳時間： 2020-06-08
上傳用戶：shancjb
If one examines the current literature on GPS receiver design, most of it is quite a bit above the level of the novice. It is taken for granted that the reader is already at a fairly high level of understanding and proceeds from there. This text will be an attempt to take the reader through the concepts and circuits needed to be able to understand how a GPS receiver works from the antenna to the solution of user position.
標簽： Fundamentals_of_Global_Positionin g_System
上傳時間： 2020-06-09
上傳用戶：shancjb
USB_MICRO USB_MNI USB扁口座 TF卡槽 SOIC8 LQFP32芯片ALTIUM 庫（3D PCB封裝庫）, 3D封裝，已在項目中使用，可以做為你的設計參考。詳細列表如下：Component Count : 94Component Name-----------------------------------------------32165032-8MHZAMS1117ANT2AntennaBATbuzzerCapCAP-0805CAP-3216CD32Crystal Oscillator 3225HC-06KEY-2PINLED-0603LQFP-100LQFP32LQFP44LQFP44 10X10_LLQFP44 10X10_MLQFP44 10X10_NLQFP48LQFP48 7X7_LLQFP48 7X7_MLQFP48 7X7_NLQFP64 10x10_LLQFP64 10x10_MLQFP64 10x10_NMagMOTONRF24L01NRF24L01-modeOLED-0.96-PIN7QFN20_4X4QFN24_4X4QFN32_5X5remoteRES-0603RFX2401CRPSG90SH1.0mm-4PINSH1.0MM-5PINSH1.0mm-6PINSMA-ANTSMA/DO-214SOIC-8SOP16SOT-23-3SOT-23-5SOT-89SOT-223SPL06-001STM32F030C8T6STM32F030F4P6STM32F103C8T6straight-1x2pinstraight-1x2pin - duplicatestraight-1x2pin - duplicate1straight-1x3pinstraight-1x3pin - duplicatestraight-1x3pin - duplicate1straight-1x4pinstraight-1x4pin - duplicatestraight-1x5pinstraight-1x8pinstraight-1x8pin - duplicatestraight-2x2pinstraight-2x3pinstraight-2x4pinstraight-2x5pinSW-NO/OFF-PIN3SW-SMD1SW-SMD2SWITCH-DIP-6*6*7SX1308TF-CARDTO-263-5TP4056USBUSB_MICROUSB_MNI_BUSB-MICRO-1winding_1x2pinwinding_1x3pinwinding_1x4pinwinding_1x5pinwinding_1x8pinwinding_2x2pinwinding_2x3pinwinding_2x4pinwinding_2x5pinXTAL-5070/SMDXTAL-QC49/SMD
標簽： usb
上傳時間： 2021-12-02
上傳用戶：aben
解讀 5G 八大關鍵技術 【摘要】5G 不是一次革命，5G 是 4G 的延續，我相信 5G 在核心網部分不會有太 大的變動，5G 的關鍵技術集中在無線部分。 在進入主題之前，我覺得首先應該弄清楚一個問題：為什么需要 5G？不是因 為通信工程師們突然想改變世界，而炮制了一個 5G。是因為先有了需求，才有了 5G。什么需求？ 未來的網絡將會面對：1000 倍的數據容量增長，10 到 100 倍的無線設備連接， 10 到 100 倍的用戶速率需求，10 倍長的電池續航時間需求等等。坦白的講，4G 網絡無法滿足這些需求，所以 5G 就必須登場。 但是，5G 不是一次革命。5G 是 4G 的延續，我相信 5G 在核心網部分不會有 太大的變動，5G 的關鍵技術集中在無線部分。雖然 5G 最終將采用何種技術，目前 還沒有定論。不過，綜合各大高端論壇討論的焦點，我今天收集了 8 大關鍵技術。 當然，應該遠不止這些。 1.非正交多址接入技術 （Non-Orthogonal Multiple Access,NOMA） 我們知道 3G 采用直接序列碼分多址（Direct Sequence CDMA ，DS-CDMA） 技術，手機接收端使用 Rake 接收器，由于其非正交特性，就得使用快速功率控制 （Fast transmission power control ，TPC)來解決手機和小區之間的遠-近問題。 而 4G 網絡則采用正交頻分多址（
標簽： 5G
上傳時間： 2022-02-25
上傳用戶：20125101110
v> 目前最常見的藍牙天線有偶極天線（dipole antenna）,倒 F 型天線（planar inverted F anternna）、曲流線型天線（meander line antenna）、微小型陶瓷天線（ceramic antenna）、液晶 聚合體天線（lcp）和棒狀天線（2.4G 頻率專用）等。由于這些具有近似全向性的輻射場型 以及結構簡單、制作成本低的優點，所以非常適合嵌入藍牙技術裝置使用。
上傳時間： 2022-03-11
上傳用戶：
