Synchronization of signals in LTE

504 different physical-layer cell ids are composed of 168 different physical-layer cell id groups each of 3 physical layer ids within the group There are – primary synchronization signal – based on a frequency domain Zadoff-Chu sequence indicating the physical layer id, – secondary synchronization signal indicating the physical layer cell id group. The mapping … Read more

How Reference signals Map in LTE?

How Reference signals Map in LTE? For channel estimation different types of reference signals are in use: – Cell specific reference signals. – MBSFN reference signals. – UE specific reference signals CELL-SPECIFIC REFERENCE SIGNALS These signals are transmitted for all non-MBSFN subframes only where subcarrier spacing is 15 kHz. In MBSFN subframes only the first … Read more

Apple and Samsung Get Sales Bans in South Korea

Two Major Mobile Product Company ban on sales by A South Korean court after it ruled that each company had infringed each other’s patents. The Seoul Central Court has imposed a sales ban on several devices as a result: Apple’s Iphone 3GS, Iphone 4 and the original Ipad and Ipad 2 tablets, along with Samsung’s GalaxyS … Read more

How Time structure in LTE?

EUTRAN OFDM symbols have a basic duration of 66.667 ?s. This means up to 2048 complex samples per OFDM symbol in time domain representation. A cyclic prefix is pretended to the symbol. The size of the cyclic prefix can be chosen from three options: Normal prefix for 15 kHz: This is the standard option. It … Read more

Layer and channel relationship in LTE

Layer and channel relationship in LTE The radio interface is composed of different layers in order to set up, reconfigure and release the radio bearer services. The protocol layer is composed of physical layer (layer 1), data link layer (layer2), and the network layer (layer3). In the E-UTRAN layer 2 is divided into two sub-layers: … Read more

MIMO Principles

MIMO is effectively radio antenna technology because multiple antennas are used at the transmitter and receiver to allow a variety of signal paths to transmit the data, with separate paths selected for each antenna so that multiple signal paths can be used. The basic mechanism behind MIMO is linear algebra. If we e.g. transmit N … Read more

QoS Mechanisms in Packet Networks

QoS Mechanisms in Packet Networks There are Three Types of QoS Mechanisms in Packet Networks. Control Plane Mechanisms Data Plane Mechanisms Its Tradeoffs Control Plane Mechanisms Such mechanisms include QoS policy management, signaling, and admission control. QoS policy management is about defining and provisioning the various levels and types of QoS services, as well as … Read more

How Transport Channel Processing in LTE?

How Transport Channel Processing in LTE? Transport channels are block oriented transmission services and transmit one or more transport blocks per transmission time interval (TTI). The TTI is 1 ms (e.g. one sub-frame). Transport blocks may in general have variable size. Typically the number of transport blocks that can be transmitted in a TTI depends … Read more

Physical Channel Types of LTE

Physical Channel Types of LTE The physical layer uses resource blocks to transmit binary coded information in QPKS, 16QAM or 64QAM or OOK modulation form. Physical channels determine how data is processed and then mapped via dynamical scheduling onto resource blocks. Thus physical channels also in EUTRAN represent the available physical resources. Like transport channels, … Read more

Transport Channel Types of LTE

Transport channels are used as the basic transmission service offered by layer 1 to MAC. MAC will use transport channels to multiplex and demultiplex logical channels onto and from them. In contrast to logical channel types, referring to the type of information transmitted, transport channel types are used to indicate the transport characteristics. This means … Read more