Beam Forming background for LTE

Beam Forming background for LTE Multiple antennas in LTE may also be used to transmit the same signal appropriately weighted for each antenna element such that the effect is to focus the transmitted beam in the direction of the receiver and away from interference, thereby improving the received SINR. The beam-forming weight vector should increase … Read more

How Spatial Multiplexing Matrix Using Two Antenna Ports in LTE

How Spatial Multiplexing Matrix Using Two Antenna Ports in LTE Spatial multiplexing is where multiple independent streams are transmitted across multiple antennas. If the receiver also has multiple antennas, the streams can be separated out using spatial multiplexing. Instead of increasing diversity, multiple antennas in this case are used to increase the data rate or … Read more

What is Basic behind MIMO for LTE

What is Basic behind MIMO for LTE MIMO and other transmit spatial diversity scheme is a newer application than receive diversity and has become widely implemented only in the early 2000s. As the signals sent from different transmit antennas interfere with one another, processing is required at both the transmitter and the receiver in order … Read more

How Normal and Extended Cyclic Prefix in LTE

How Normal and Extended Cyclic Prefix in LTE The key to making OFDM realizable in practice is the use of the FFT algorithm, which has low complexity. In order for the IFFT/FFT to create an ISI-free channel, the channel must appear to provide a circular convolution. Adding cyclic prefix to the transmitted signal to create … Read more

LTE Frame Structure and Resource Block Architecture

LTE Frame Structure and Resource Block Architecture The figure below shows the LTE frame structure under Time division mode (TDD) Type 2 and Frequency Division mode (FDD) Type 1. Differences in LTE Frame Structure Main differences in LTE Frame Structure between the two modes are Frame 0 and frame 5 (always downlink in TDD) Frame … Read more

OFDM and SC-FDMA Fundamental

OFDM and SC-FDMA Fundamental OFDM was selected for the downlink because it can Improved spectral efficiency Reduce ISI effect by multipath Provide better Protection against frequency selective fading OFDM is a scheme that offers good resistance to multipath and is now widely recognized as the method of choice for mitigating multipath for broadband wireless. It … Read more

How MU-MIMO Framework in LTE

How MU-MIMO Framework in LTE MU-MIMO is widely considered a key technology for system capacity improvement in modern wireless networks. In contrast to SU-MIMO, where the spatial multiplexing gain is confined to a single user, MU-MIMO allows multiple users to be co-scheduled on the same time-frequency resources to exploit this gain among two or more … Read more

MIMO Feedback in LTE Rel 8

MIMO Feedback in LTE Rel 8 CSI feedback allows downlink transmission to be adaptively optimized based on the instantaneous DL channel, so that closed loop beamforming and adaptive link adaptation can be enabled to optimize the system performance. The DL reference signal used for CSI measurement is different in Rel-8 and Rel-10. In Rel-8, CSI … Read more

How SU-MIMO Framework in LTE Rel 8

How SU-MIMO Framework in LTE Rel 8 SU-MIMO is one of the key technologies in LTE Rel 8. There are two major operations under SU-MIMO: transmit diversity and spatial multiplexing. Transmit diversity is an efficient way to improve the reliability of a system. Accordingly, it is used in LTE Rel-8 for control channel and data … Read more

Intra RAT HO events in LTE

Intra RAT HO events in LTE Below is the List and How Intra RAT HO events in LTE. Event A1 : Serving becomes better than threshold Event A2 : Serving becomes worse than threshold Event A3 : Neighbor becomes offset better than serving Event A4 : Neighbor becomes better than threshold Event A5 : Serving … Read more