Hybrid ARQ (HARQ) in LTE Hybrid ARQ (HARQ) leads to higher efficiency in transmission and error correction. There is one HARQ entity per UE with 8 stop-and-wait processes for each HARQ entity. Both incremental redundancy and chase combining are supported. The number of HARQ retransmissions targeted by the HARQ protocol depends on the network configuration. … Read more
How CQI, PMI and RI reporting by UE in LTE? The UE is requested to send either periodic or a periodic reports concerning • Rank indication (RI) Reports are applicable for closed- and open-loop spatial multiplexing. In case of open-loop TRI=1 corresponds to transmit diversity and TRI>1 to large delay CDD. • Precoding matrix indicator … Read more
Modulation and TB size LTE Modulation Techniques In Long-Term Evolution (LTE) networks, modulation is a fundamental aspect of the physical layer responsible for encoding digital information into analog signals for transmission. LTE employs various modulation schemes to adapt to different channel conditions and maximize data rates. The primary modulation schemes used in LTE include: Quadrature … Read more
Based on DCI formats Resource allocation in LTE Based on DCI formats In LTE Three types of allocation are used: type 0: DCI formats 1, 2, 2A type 1: DCI formats 1, 2, 2A type 2: DCI formats1A, 1B, 1C, 1D One bit in the header is indicating if DCI formats 1, 2, 2A are … Read more
T-Mobile USA Deal with Crown Castle about $2.4 Billion Towers T-Mobile USA has signed a US$2.4 billion deal with Crown Castle that lets the towers operator have sole rights to use and lease out 6,400 of T-Mobile’s towers for the next 28 years. The deal also includes the sale of 800 towers to Crown Castle. … Read more
Power ramping in LTE 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 … Read more
Non-contention vs Contention Access procedure in LTE 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 … Read more
Uplink Power Control Calculation in LTE Transmit power of PUSCH in subframe i is defined by PPUSCH (i) = min{PMAX,10 log10 (MPUSCH (i)) + PO_PUSCH ( j) +α ( j) ⋅ PL + ΔTF (i) + f (i)} [dBm] Pmax: max. allowed power, MPUSCH: number of scheduled RBs, PL: pathless [dB]. ΔTF (i) = 10 … Read more
Downlink Power control in LTE The eNodeB determines the downlink transmit energy per resource element (lte epre). Downlink cell-specific reference-signal (RS) lte epre is constant across the downlink system bandwidth and constant across all subframes until different cell-specific RS power information is received. The downlink RS lte epre is given by the parameter Reference-signal-power provided by higher … Read more
Principle of Power control in LTE 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 … Read more