The 3G LTE uses 3 Quadrature Amplitude Modulations (QAMs) depending on the radio quality. QAM uses both the amplitude and the phase. LTE devices use QPSK, 16QAM and 64QAM to modulate data and control information. The eNodeB supports all of these modulation techniques for the downlink direction. However, 64QAM is optional in the uplink direction. … Read more
LTE parameters Equipment related parameters include the base station, antenna, and terminal. The link budget parameters vary with the base stations, antennas, and terminals of different vendors. These parameters affect the link budget result. As a result, the downlink is unaffected in most scenarios. List of LTE parameters in LTE link Budget LTE Transmit Power LTE Power Combining … Read more
Cell Edge Rate in LTE is simple if it’s High then Coverage Low and if It’s Low then Coverage high similar to Frequency selection. Not clear lets understand in detail. Cell Edge Rate in LTE Similar to other wireless communications systems, such as CDMA2000 EVDO, WiMAX and HSPA, the LTE features a rate layering feature. … Read more
Here I write about what is main work of Acquisition Indicator Channel AICH in 3G There is 2 types main work of AICH Carrying the Acquisition Indicators (AI), SF = 256 There are 16 kinds of Signature to generate AI The Acquisition Indicator Channel (AICH) is a common downlink channel used to control the uplink … 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
Main Work of Primary Common Pilot Channel (PCPICH) in WCDMA is as below. Carrying pre-defined sequence Fixed channel code: Cch, 256, 0, Fixed rate 30Kbps Scrambled by the primary scrambling code Broadcast over the entire cell A phase reference for SCH, Primary CCPCH, AICH, PICH and downlink DPCH, Only one PCPICH per cell The Common … Read more
Here I write Interference Margin in simple word and basic definition of interference margin in LTE. Let understands it. Interference margin accounts for the increase in the terminal noise level caused by the interference from other users. LTE uplink is orthogonal if it is within the same cell so there is no intra-cell interference. However, … Read more
Here I write down one basic idea of Spectrum reframing in LTE and why operators require spectrum reframing for LTE. Operators worldwide are looking forward to new LTE technologies deployment but not every one of them possess brand new spectrum required for LTE deployment. As a result, many networks are expected to perform some level … Read more
Choosing which frequency band to operate a LTE network is one of the most critical decision. Operator has to make when it comes to capacity planning. The frequency propagation and penetration characteristics will determine the number of sites that need to be built in order to cover the designated area chosen by the Operator. This … Read more
Mobile (Portable) and fixed link between the proportion of the budget, there are four major Differences. The first difference between the fixed link will have a higher budget is usually Case-antenna mobile users have more. A second difference is For certain cases the loss of body assumed. The third difference between building / vehicle penetration … Read more