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
In mobile communications two main categories of antennas used are Omni and Directional antenna here I write about antenna characteristics and use. ANTENNA TYPES Omni directional antenna These antennas are mostly used in rural areas. In all horizontal direction these antennas radiate with equal power. In the vertical plane these antennas radiate uniformly across all … Read more