Slide title In CAPITALS 50 pt Slide subtitle 32 pt POWER CONTROL UMTS Seminar
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential Principles The two main capabilities of Power Control in a WCDMA system are as follows: –To maintain the quality of connections (including common channels needed, for example, for call access) –To minimize the transmitted power in both uplink and downlink
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential Key Characteristics Control channel power setting (DL only, Fixed) – Setting of the output power for CPICH, P-CCPCH, S- CCPCH, SCH, PICH, AICH Open loop power control (Subject to power control) – Power control during random access# (UL) – DL DPDCH/DPCCH setting (and DL ramping) – DL power drift prevention (mitigation of power drift during SHO) – UL DPDCH/DPCCH setting Inner loop power control – Fast power regulation towards a SIRtarget Outer loop power control – Regulation of SIRtarget towards desired BLER
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential Control Channel Power Setting PCPICH_POWER = dBm (default = 30.0) For the common control channels below the power is relative the CPICH –MAX_FACH1_POWER = dB, (1.8) –MAX_FACH2_POWER = dB, (1.5) –BCH_POWER = dB, (-3.1) –P_SCH_POWER = dB, (-1.8) –S_SCH_POWER = dB, (-3.5) –AICH_POWER = dB, (-6.0) –PICH_POWER = dB (-7.0) –PCH_POWER = dB (-0.4)
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential Radio Link Setup, RAB Establishment Soft Handover, Power Balancing Compressed Mode, Inter-Frequency Handover Power Control on Dedicated Channels
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential UL Power Control Overview
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential The power of the first preamble is controlled by UL open loop PC, as well as the ramping step, the preamble threshold and “the number of retransmission attempts” Power Ramping on RACH
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential Initial Power Setting on DL DPCCH/DPDCH Initial DL DPDCH power at call setup –This is done in the RNC and the result is transferred to the RBS –The algorithm uses SF, measure Ec/I0 on PCPICH, transmitted power on PCPICH and the service requirements (SIRDPDCH_init) as input –PDL_DPDCH = PPCPICH + (SIRDPDCHinit - (Ec/ No)PCPICH) + Cbackoff -10log(SFDL_DPDCH/2) Initial DL DPCCH power –PDL_DPCCH_TFCI = PDL_DPDCH + PO1 –PDL_DPCCH_TPC = PDL_DPDCH + PO2 –PDL_DPCCH_PILOT = PDL_DPDCH + PO3
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential The initial uplink power in DPCCH is determined according to equation (8). This provides reliable setup of the radio link, while avoiding excessive power, which causes unnecessary interference Uplink Power Control
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential SIRest Outer loop control SIRtarget TPC = up/down The UL inner loop power control should keep the estimated SIR of a radio link set at the SIRtarget UL inner power control algorithm controls simultaneously the power of the DPCCH and its associated DPDCH by increasing/decreasing the power in steps of 1 dB (the same adjustment for both DPCCH and DPDCH) according to SIRest >= SIRtarget TPC = “down” SIRest < SIRtarget TPC = “up” UL Inner Loop Power Control SIRest in RBS (on pilot) TPC sent to UE
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential SIRtarget only within certain limits i.e. SIR_MIN ≤ SIRtarget ≤ SIR_MAX A jump regulator is choosing algorithm 0 i.e. ULOUTERLOOPREGULATOR=0 If CRC=OK then the SIRtarget is lowered by UL_SIR_STEP/UP_DOWN_RATIO If CRC=NG then the SIRtarget is increased by UL_SIR_STEP UL outer loop power control
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential Transport block number Jump Regulator Example SIRtarget CRC = NG SIRtarget = [-0/(1x199) + 1/1] dB =5.9 dB SIRtarget = [-1/(1x199) + 0/1] dB =5.895 dB CRC = OK ulInitSirTarget (speech = 4.9 dB) Will continue to drop until another CRC = NG is detected
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential RBS RNC Outer Loop updating of SIRtarget Iub SIRtarget = 4.9 dB Jump regulator Result CRC NG => dB SIRtarget = 5.9 dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB CRC OK => dB SIRtarget = 5.8 dB Resolution of signaling is limited to 0.1 dB
Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Confidential