lte
The major basic concept concerned with the radio path transmission of the GSM system is the burst sequence (simplified as Burst). It is a string of transmission units including more than 100 modulation bits. The burst sequence has a restricted duration and seizes a restricted radio frequency spectrum. They can be described as output from … Read more
Actually, during the communication process, the mobile subscriber talks only 40% of the time and there is not much useful information transmitted during rest of the time. If all the information is transmitted to the network, it will not only be a waste of the system resources but also add more interference to the system. … Read more
To check and correct errors during the transmission, redundancy data and the information calculated from the source data are added to the stream so as to increase the bit rate. For the voice, the length of these codes is 456 bits every 20ms. The bit rate of code stream output from the voice coder is … Read more
Open loop power control together with optional power ramp-up is used during the random access process at the beginning of the connection until more accurate control information is available. Power loss due to transmission distance depends on to the increase of the distance between NodeB and the UE. In such a case, feedback information from another side is not … Read more
Here I write short notes on how to test open loop and close loop testing in lte and what idea behind it. In open loop no any data send back and in closed loop all relevant data available to both side lets check in some detail. Open and close loop testing in LTE: Open loop … Read more
Power control – already being applied in 2nd and 3rd generation networks – has high potential for improvement of the performance of mobile networks. Main benefits are: 1. It can bring down the interference in up- and downlink and hence enhances the capacity of the networks. 2. Additionally it helps to keep down the uplink-power … Read more
RE – groups & CFI – Control Format Indication in LTE is as below. RE – groups In order to support DL control information mapping, RE-groups are defined. Four useful symbols are bundled, useful in the sense that RE’s carrying the cellspecific reference symbols are not available. The one cell-specific RS case is mapped in … Read more
The action of camping on provides access to services. The network provides different levels of service to a UE in either Idle mode or Connected mode. Three levels of services are defined: LIMITED SERVICE: emergency calls on an acceptable cell. Acceptable cell: UE may camp to obtain limited service like emergency call. The minimum set … Read more
Random access procedure is performed for the following five events: • Initial access from RRC_IDLE; • RRC Connection Re-establishment procedure; • Handover; • DL data arrival during RRC_CONNECTED requiring random access procedure; • UL data arrival during RRC_CONNECTED requiring random access procedure; E.g. when UL synchronization status is “non-synchronized” or there are no PUCCH resources for … Read more
LTE RAN provides the physical radio link between the User Equipment (UE) and the Evolved Packet Core (EPC) network. LTE RAN comprises eNodeBs. The eNodeB contains Transmit Receive Duplex Units (TRDUs) or Remote Radio Heads (RRHs) and communicates with the UEs. The eNodeB supports Multiple Input Multiple Output (MIMO). The LTE RAN – eNodeB provides: … Read more