Multi-antenna Techniques LTE to improve the downlink performance There are five methods of multiple antennas have been defined for the LTE downlink to improve the performance: Receive diversity at the mobile Transmit diversity using SFBC at the eNB (evolved Node B) MIMO spatial multiplexing at the eNB, for one or two users Cyclic Delay Diversity … Read more
WiMAX antennas, just like the antennas for car radio, cell phone, FM radio, or TV, are designed to optimize performance for a given application. The figure above illustrates the three main types of antennas used in WiMAX deployments. From top to bottom are an omni directional, sector and panel antenna each has a specific function. … Read more
In This article you found Application of Tx diversity modes on UMTS downlink physical channel or in other word transmit diversity mode in UMTS. Transmitter-antenna diversity can be used to generate multi-path diversity in places where it would not otherwise exist. Multi-path diversity is a useful phenomenon, especially if it can be controlled. It can … Read more
Transmit spatial diversity is a newer phenomenon than receive diversity and has become widely implemented only in the early 2000s. Because the signals sent from different transmit antennas interfere with one another, processing is required at both the transmitter and the receiver in order to achieve diversity while removing or at least attenuating the spatial … Read more
The air interface is the radio-based communication link between the mobile station and the active base station. LTE air interface supports high data rates. LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) for downlink transmission to achieve high peak data rates in high spectrum bandwidth. LTE uses Single Carrier Frequency Division Multiple Access (SC-FDMA) for … Read more
Time switching transmit diversity TSTD in UMTS is used only on UMTS SCH channel Time-switched transmit diversity (TSTD) can be applied to the UMTS SCH. Just like Space time block coding based transmit antenna diversity STTD, the support of Time switching transmit diversity is optional in the UMTS UTRAN, but mandatory in the UE. The … Read more
During detailed design, the main task is to determine the exact type and placement of the Antenna, to ensure sufficient coverage to meet the requirements. During this process, the physical properties of the Antenna must be kept in mind, as they may affect the design of the Antenna system. Many indoor Antennas are available with … Read more
Indoor solutions required? First, to analyze whether the macro cell coverage is enough. Even if the macro analysis of the project and the macro network test-drive network has sufficient coverage, additional site survey should confirm that all the target areas are covered and, more importantly, the fact that the dominant server can be found in … Read more
A DAS contains the same active components present in a DAS passive, with the addition of active devices such as amplifiers, repeaters or amplifiers bidirectional (BDAS) to amplify and / or radio signals shipping. This enables an active DAS to cover a much larger area of a passive DAS. Active distribution systems, however, are more … Read more