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BAND

  • SPREAD SPECTRUM MODULATION TECHNIQUES -spread spectrum - those modulation methods that are producin

    SPREAD SPECTRUM MODULATION TECHNIQUES -spread spectrum - those modulation methods that are producing a signal whose spectrum is more wider than of the data signal, the occupied frequency BAND being independent by the signal of data BAND. -The signals with spread spectrum of direct sequence type BPSK (BPSK-DS-SS) -The signals with spread spectrum of direct sequence type QPSK – DS–SS - Frequency hopping spread spectrum signals (FH-SS)

    标签: MODULATION TECHNIQUES modulation SPECTRUM

    上传时间: 2017-06-05

    上传用户:lht618

  • Frequency domain characterization of los nonfading indoor wireless LAN channel employing frequency a

    Frequency domain characterization of los nonfading indoor wireless LAN channel employing frequency and polarization diversity in the 63.4 to 65.4GHz BAND

    标签: characterization Frequency employing frequency

    上传时间: 2013-12-22

    上传用户:zhaoq123

  • A basic Fourier transform identity coupled with an iterative convergence algorithm provides a powerf

    A basic Fourier transform identity coupled with an iterative convergence algorithm provides a powerful method to align BAND-limited signals.

    标签: convergence algorithm transform iterative

    上传时间: 2017-08-03

    上传用户:hphh

  • 檔案傳輸協定(FTP)為目前相當普遍與廣泛使用之網路 應用。然而在傳統檔案傳輸協定之設計下

    檔案傳輸協定(FTP)為目前相當普遍與廣泛使用之網路 應用。然而在傳統檔案傳輸協定之設計下,資料 傳輸透過Out-of-BAND(OOB)之機制,意即透過控制頻道(control channel)傳輸指令 ,而實際資料 傳輸則另外透過特定之通訊埠以及TCP連 線,進行 傳送。如此一來 可確保資料 傳輸之可靠與穩定性,但另一方面則會造成傳輸率 (throughput)效能低落 。因此,在本計劃中,我們透過使用SCTP協定並利 用多重串 流 (multi-stream)機制,達到以In-BAND機制達成Out-of-BAND傳輸之相同效果。在本研究之最後亦透過於開放原始碼系統實作並實際量 測,証

    标签: 63799 FTP

    上传时间: 2013-12-10

    上传用户:2467478207

  • dual-BAND microstrip antenna

    一种双频微带天线方案的分析与设计

    标签: antenna

    上传时间: 2015-05-05

    上传用户:puzzle0612

  • 基于频率插值的4.0kbps 语音编码器的性能和设计(英文)

    The 4.0 kbit/s speech codec described in this paper is based on a Frequency Domain Interpolative (FDI) coding technique, which belongs to the class of prototype waveform Interpolation (PWI) coding techniques. The codec also has an integrated voice activity detector (VAD) and a noise reduction capability. The input signal is subjected to LPC analysis and the prediction residual is separated into a slowly evolving waveform (SEW) and a rapidly evolving waveform (REW) components. The SEW magnitude component is quantized using a hierarchical predictive vector quantization approach. The REW magnitude is quantized using a gain and a sub-BAND based shape. SEW and REW phases are derived at the decoder using a phase model, based on a transmitted measure of voice periodicity. The spectral (LSP) parameters are quantized using a combination of scalar and vector quantizers. The 4.0 kbits/s coder has an algorithmic delay of 60 ms and an estimated floating point complexity of 21.5 MIPS. The performance of this coder has been evaluated using in-house MOS tests under various conditions such as background noise. channel errors, self-tandem. and DTX mode of operation, and has been shown to be statistically equivalent to ITU-T (3.729 8 kbps codec across all conditions tested.

    标签: frequency-domain interpolation performance Design kbit_s speech coder based and of

    上传时间: 2018-04-08

    上传用户:kilohorse

  • AD826

    High-Speed, Low-Power Dual Operational Amplifier The AD826 features high output current drive capability of 50 mA min per amp, and is able to drive unlimited capacitive loads. With a low power supply current of 15 mA max for both amplifiers, the AD826 is a true general purpose operational amplifier. The AD826 is ideal for power sensitive applications such as video cameras and portable instrumentation. The AD826 can operate from a single +5 V supply, while still achieving 25 MHz of BAND width. Furthermore the AD826 is fully specified from a single +5 V to ±15 V power supplies. The AD826 excels as an ADC/DAC buffer or active filter in data acquisition systems and achieves a settling time of 70 ns to 0.01%, with a low input offset voltage of 2 mV max. The AD826 is available in small 8-lead plastic mini-DIP and SO packages.

    标签: 826 AD

    上传时间: 2020-04-19

    上传用户:su1254

  • Distributed Antenna Systems

    The rapid growth in mobile communications has led to an increasing demand for wide- BAND high data rate communications services. In recent years, Distributed Antenna Systems (DAS) has emerged as a promising candidate for future (beyond 3G or 4G) mobile communications, as illustrated by projects such as FRAMES and FuTURE. The architecture of DAS inherits and develops the concepts of pico- or micro-cell systems, where multiple distributed antennas or access points (AP) are connected to and con- trolled by a central unit.

    标签: Distributed Antenna Systems

    上传时间: 2020-05-27

    上传用户:shancjb

  • Essentials+of+LTE+and+LTE-A

    The next-generation wireless broadBAND technology is changing the way we work, live, learn, and communicate through effective use of state- of-the-art mobile broadBAND technology. The packet-data-based revolu- tion started around 2000 with the introduction of 1x Evolved Data Only (1xEV-DO) and 1x Evolved Data Voice (1xEV-DV) in 3GPP2 and High Speed Downlink Packet Access (HSDPA) in 3GPP. The wireless broad- BAND fourth-generation technology (4G) is an evolution of the packet- based 3G system and provides a comprehensive evolution of the Universal Mobile Telecommunications System specifications so as to remain competitive with other broadBAND systems such as 802.16e (WiMAX)

    标签: Essentials LTE-A LTE and of

    上传时间: 2020-05-27

    上传用户:shancjb

  • HSDPAHSUPA+for+UMTS+High+Speed+Radio+Access

    The first Third Generation Partnership Project (3GPP) WideBAND Code Division Multiple Access (WCDMA) networks were launched during 2002. By the end of 2005 there were 100 open WCDMA networks and a total of over 150 operators having frequency licenses for WCDMA operation. Currently, the WCDMA networks are deployedinUniversalMobileTelecommunicationsSystem(UMTS)BANDaround2GHz in Europe and Asia including Japan and Korea. WCDMA in America is deployed in the existing 850 and 1900 spectrum allocations while the new 3G BAND at 1700/2100 is expected to be available in the near future. 3GPP has defined the WCDMA operation also for several additional BANDs, which are expected to be taken into use during the coming years.

    标签: HSDPAHSUPA Access Speed Radio UMTS High for

    上传时间: 2020-05-27

    上传用户:shancjb