A Study On Antenna Hopping - 1780 Words

antenna hopping. In a system using antenna hopping, two or more transmit antennas are used interchangeably to achieve a diversity effect. Antenna hopping attracted attention from 1990s and comparatively in expansive way of achieving a transmit diversity gain in system such as GSM. The principle goal of MIMO technology is to improve either the quality (BER) or the data rate of the communication by means of adequate signal processing techniques at both ends of the system. The capacity can increase linearly with the number of antennas when using MIMO system. MIMO can obtain both multiplexing gain and diversity gain thus significantly increasing the system capacity as well as improving the reliability of the wireless link. Having high spectral†¦show more content†¦STCs necessitate the transmission of multiple redundant copies of data so that there is possibility of receiving some copies of data through some are lost due to deep fading to enhance reliability of the data transmission. STCs are two types namely space–time trellis codes (STTCs) and space-time block codes (STBCs). STTC has been inaugurated as a coding technique that promises full diversity and considerable coding 5 gain but decoding complexity is very high. To avoid this, STBCs have been proposed by the effort work of Alamouti for transmit diversity and later Vahid Tarokh, Hamid Jafarkhani and Robert Calderbank made their contributions.[1-3]. This code gives better second order diversity when used with a single receive antenna and fourth order diversity when used with two antennas at the receiver side. But, it is only half rate, because it only transmits two symbols using the two time slots and two transmit antenna. 1.2 LITERATURE REVIEW [1]S. M. Alamouti, describes a simple two-branch transmit diversity scheme. Using two transmit antenna and one receive antenna, the new transmit antenna provides the same diversity order as maximal-ratio receiver combining (MRRC) with one transmit and two receive antennas. The scheme easily be generated to two transmit antenna and M receive antenna to provide a diversity order of 2M. This scheme does not require any bandwidth expansion any feedback from the receiver to theShow MoreRelatedRadio Network Performance For Indoor Cellular Systems1163 Words   |  5 Pageswireless deployment is presented that meets indoor capacity need and provides good indoor coverage. Antenna hopping is done, which transmits information continuously on different antennas. The Radio Resource management problem in a novel Indoor Base Station (IBS) system is worked out. It can be found that the capacity of the centralized radio network controller is four times the capacity of distributed antennas system. 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The GSM study group aimed to provide the followings through the GSM: ââ€" ª Improved spectrum efficiency. ââ€" ª International roaming. ââ€" ª Low-cost mobile sets and base stations (BSs) ââ€" ª High-quality speech ââ€" ª Compatibility with Integrated Services DigitalRead MoreScada5426 Words   |  22 Pagesas shown in the table below (Figure 4): Figure 4: Nine-component approach to analyzing operational and functional requirements of a SCADA system 4.5.1 Mission The mission defines the reason for the existence of the particular SCADA system under study. In any organization, business systems dictate policy and procedures relevant to the control and monitoring of the process; conceptually, these reside above the Master Station. Similarly, the sensors and actuators directly act upon the physical objectsRead MoreCrossing the Chasm76808 Words   |  308 Pagesimportance of evidence and the necessity to document its sources. 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