In UL, the UE has no dedicated resources to transmit directly when new data arrived in the buffer from higher layer. It requests resources to transmit them. It receives radio resources. It transmits them. The scheduling request is sent on the Physical Uplink Control Channel (PUCCH). This channel carries radio signaling in uplink: Scheduling … Read more
The DL scheduler is spit into 3 functional parts: 1.The Static Scheduler: Which assigns a fixed amount of Transport Blocks as well as PDCCH and PDSCH resources for the BCCH over the DL-SCH Transport Channel.Those resources are permanently allocated. 2.The Semi-static Scheduler: Which assigns Transport Blocks as well as PDCCH and PDSCH resources for PCCH … Read more
Peak data rate 100Mbps (DL) and 50Mbps (UL) to 20MHz Throughput increased by 3-4 times and 2-3 times for the downlink to uplink from HSDPA Rel6 (DL=14.4Mbps, to use transmitter sites that have been used in UTRA/GERAN Throughput increased by 3-4 times and 2-3 time UL=5.7Mbps) Spectrum efficiency by continuing as for the downlink to … Read more
The PDCCH, Physical Downlink Control Channel, allocates the DL and UL resources. There is one PDCCH per sub-frame. It helps the UE retrieve the transport blocks from the PDSCH: Allocated RB Modulation and Coding Scheme (MCS) Multi-antenna transmission PDCCH Shared between all UE of the cell Each TTI contains an aggregation of PDCCH allowing … Read more
These UE categories are often referred to as UE classes. The low end UE does not support MIMO but the high end UE will support 4×4 MIMO Whatever category a UE belongs to, it has to be capable of receiving transmissions from up to four antenna ports. This is because the system information can be … Read more
How 3G Spectrum Allocation? 3G Spectrum Allocation is different in different country but mainly its all having as per below figure. ITU has allocated 3G Spectrum Allocation 230 MHz frequency for the 3G mobile communication system IMT- 2000: 1885 ~ 2025MHz in the uplink and 2110~ 2200 MHz in the downlink. Of them, the frequency … Read more
One of the advantages of using LTE TDD is that it is possible to dynamically change the up and downlink balance and characteristics to meet the load conditions. In order that this can be achieved in an ordered fashion, a total of seven up / downlink configurations have been set within the LTE standards, in … Read more
In any two-way radio system, the radio pathlosses and the equipment output powers and sensitivities must be taken into account for both directions. This is especially true in a mobile network (e.g. downlink: BS to UE and uplink: UE to BS), where there are different characteristics for the uplink and downlink paths. These include, for … Read more
LTE devices use several modulation techniques to modulate data and control information. These modulation techniques include: QPSK (2 bits per symbol), 16QAM (4 bits per symbol), and 64QAM (6 bits per symbol). All of these modulation techniques are supported in the downlink direction; and all but 64QAM, which is optional, are supported in the uplink … Read more
If some knowledge of the downlink channels of the different transmit antennas, (more specifically some knowledge of the relative channel phases) is available at the transmitter side, multiple transmit antennas can be used to shape the overall antenna beam in the direction of a target receiver. In general, such beamforming can increase the signal-strength at … Read more