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LTE_UL_EVM (Uplink EVM (RCE) Measurement)


Description: Uplink EVM (RCE) Measurement
Library: LTE, Measurement

Parameters
Name Description Default Unit Type Range
RF_Parameters RF parameters for LTE uplink signals Category   string  
RIn source resistance 50 Ohm Ohm int (0,∞)
RTemp temperature - 273.15 Celsius real [- 273.15,∞]
RefFreq internal reference frequency 2500 MHz Hz real (0,∞)
Sensitivity voltage output sensitivity, Vout/Vin 1   real (-∞,∞)
Phase Reference phase in degrees 0.0 deg real (-∞,∞)
GainImbalance gain imbalance in dB Q channel relative to I channel 0.0   real (-∞,∞)
PhaseImbalance phase imbalance in dB Q channel relative to I channel 0.0   real (-∞,∞)
SystemParameters system parameters for LTE uplink signals Category   string  
SpecVersion Specification select from May 08 or Semptember 08: Version_05_08, Version_09_08 Version_09_08   enum  
FrameMode frame mode: FDD, TDD FDD   enum  
TDD_Config downlink and uplink allocations for TDD: Config 0, Config 1, Config 2, Config 3, Config 4, Config 5, Config 6 Config 0   enum  
SpecialSF_Config special subframe configuration for TDD: Config 0, Config 1, Config 2, Config 3, Config 4, Config 5, Config 6, Config 7, Config 8 Config 4   enum  
Bandwidth bandwidth: BW 1.4 MHz, BW 3 MHz, BW 5 MHz, BW 10 MHz, BW 15 MHz, BW 20 MHz BW 5 MHz   enum  
OversamplingOption oversampling ratio option: Ratio 1, Ratio 2, Ratio 4, Ratio 8 Ratio 2   enum  
CyclicPrefix type of cyclic prefix: Normal, Extended Normal   enum  
CellID_Sector the index of cell identity within the physical-layer cell-identity group 0   int [0,2]
CellID_Group the index of cell identity group 0   int [0,167]
n_RNTI radio network temporary identifier 0   int [0,65535]
HalfCarrierShift_Enable whether or not to enable 1/2 subcarrier shifting: NO, YES YES   enum  
IdleInterval idle interval between two consecutive radio frames 0 sec real [0,1.0e-3]
PUSCH_Parameters PUSCH parameters for LTE uplink signals Category   string  
PUCCH_PUSCH PUCCH and PUSCH selection: PUSCH, PUCCH, both PUSCH   enum  
Payload_Config the configuration mode of input data of PUSCH.: MCS index, Transport block size, Code rate Transport block size   enum  
Payload the input payload for PUSCH, the meaning of the input is defined in Payload_Config {2555, 2555, 2555, 2555, 2555, 2555, 2555, 2555, 2555, 2555}   real array  
MappingType the modulation orders for the PUSCH in each subframe. (0:QPSK, 1:16QAM, 2:64QAM) {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}   int array  
CRC_Length Number of parity bits: CRC_24A, CRC_24B, CRC_16, CRC_8 CRC_24A   enum  
RV_Idx Redundancy Version Index 0   int [0, 3]
DFTSwap_Enable PUSCH DFT swap is enable: NO, YES YES   enum  
RB_AllocType RB allocation type: StartRB + NumRBs, RB indices (1D), RB indices (2D) StartRB + NumRBs   enum  
RB_Alloc the RB allocation for PUSCH, in the fomats of [start RB, number of RBs] or[[SF0 start RB, SF0 number of RBs], ..., [SF9 start RB, SF9 number of RBs]] {0, 25}   int array  
GroupHop_Enable whether enable group hopping for DMRS on PUCCH and PUSCH or not: NO, YES NO   enum  
SeqHop_Enable whether enable sequence hopping for DMRS on PUSCH or not: NO, YES NO   enum  
PUSCH_Delta_ss used in determining the sequence-shift pattern for PUSCH 0   int [0,29]
PUSCH_n_DMRS1 used in computing the cyclic shift for PUSCH DMRS 0   int  
PUSCH_n_DMRS2 used in computing the cyclic shift for PUSCH DMRS {0}   int array  
PUCCH_Parameters PUCCH parameters for LTE uplink signals Category   string  
PUCCH_Format PUCCH format: Format 1, Format 1a, Format 1b, Shortened 1a, Shortened 1b, Format 2, Format 2a, Format 2b Format 1   enum  
PUCCH_Delta_shift used to calculate PUCCH cyclic shift Alfa 2   int [1,3]
PUCCH_Delta_offset used to calculate PUCCH cyclic shift Alfa 0   int [0,2]
PUCCH_SF_Alloc which sub frames contain the PUCCH, valid when PUCCH_PUSCH is other than PUSCH {2}   int array [0,9]
PUCCH_NRB2 number of RBs used for transmisstion PUCCH format 2/2a/2b 1   int [0,100]
PUCCH_n1 resources used for transmisstion PUCCH format 1/1a/1b 11   int [0,12*100-1]
PUCCH_n2 resources used for transmission PUCCH format 2/2a/2b 11   int [0,12*PUCCH_NB2-1]
PRACH_Parameters PRACH parameters for LTE uplink signals Category   string  
PRACH_Enable whether or not to enable PRACH: NO, YES NO   enum  
PRACH_Config PRACH configuration index 0   int [0,63]
PRACH_Mapping the PRACH mapping patterns. In FDD, it indicates the subframe number where the preamble starts; in TDD, it indicates the index of preamble mapping pattern in time and frequency {1}   int array [0,9]
PRACH_PrmbleIndex preamble indexes, used to select preamble sequences from 64 preambles available in this cell {0}   int array [0,63]
PRACH_RBOffset PRACH frequency offset, the first RB available for PRACH 0   int [0,94]
PRACH_u logical index of root ZC sequence 0   int [0,837]
PRACH_Ncs cyclic shifts of ZC sequence 0   int [0,15]
PRACH_HS_flag high speed flag: NO, YES NO   enum  
SRS_Parameters SRS parameters for LTE uplink signals Category   string  
SRS_Enable sounding reference symbol is enable: NO, YES NO   enum  
SRS_BW the SRS bandwidth in RB 4   int [4,100]
SRS_SC_Start the start subcarrier of the SRS 0   int [0,12*100-1]
SRS_SF_Config SRS subframe configuration 0   int [0,14]
SRS_CS used in computing the cyclic shift of SRS 0   int [0,7]
PowerParameters power-related parameters Category   string  
PUSCH_PwrOffset the power offset in dB for PUSCH 0   real (-∞, +∞)
PUSCH_RS_PwrOffset the power offset in dB for PUSCH RS 0   real (-∞, +∞)
PUCCH_PwrOffset the power offset in dB for PUCCH 0   real (-∞, +∞)
PUCCH_RS_PwrOffset the power offset in dB for PUCCH RS 0   real (-∞, +∞)
PRACH_PwrOffset the power offset in dB for PRACH 0   real (-∞, +∞)
SRS_PwrOffset the power offset in dB for SRS 0   real (-∞, +∞)
ControlInfoParameters control information parameters for LTE uplink signals Category   string  
RI_NumCodedSyms number of coded RI symbols {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}   int array [0,∞)
CQI_NumCodedSyms number of coded CQI symbols {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}   int array [0,∞)
HARQACK_NumCodedSyms number of coded HARQ-ACK symbols {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}   int array [0,∞)
RxAlgorithmParameters parameters for LTE uplink receiver algorithm Category   string  
IQ_Offset_Correct whether or not to correct IQ offset: NO, YES YES   enum  
PreDownsampling pre-downsampling to 1X symbol rate: NO, YES NO   enum  
Sym_StartPos the start position of the negative offset value to the CP length(without oversampling) to get the OFDM symbol for FFT operation {-3,-3}   int array  
ChEstInterval the interval for channel estimation: PerSlot, PerSubFrame PerSlot   enum  
ChEstimatorMode mode of interpolation algorithm in channel estimator: Linear, MMSE Linear   enum  
SNR SNR in dB. (used by MMSE channel estimator in PUSCH) 15   real (-∞,∞)
Tmax the maximum delay of multi-path channel. (used by MMSE channel estimator in PUSCH) 1.0 usec sec real [0,∞)
Fmax the maximum doppler frequency. (used by MMSE channel estimator in PUSCH) 100 Hz Hz real [0,∞)
DemapperType symbol demodulation type: Hard, Soft Soft   enum  
DemapperMaxLevel the maximum level for soft demapping output when DemapperType is Soft or CSI 1.0   real (0,∞)
TC_Iteration Turbo decoder iteration number 4   int [1,20]
FramesToAverage number of frames that will be averaged if AverageType is RMS (Video) 10   int [1,∞)
DisplayOption display option: Percentage, dB, Percentage_dB Percentage   enum  
MeasurementOption measurement option: Per_PhysicalCh, Per_Subcarrier, Per_PhysicalCh_Subcarrier Per_PhysicalCh   enum  
Pin Inputs
Pin Name Description Signal Type
1 RF_Signal input of RF signal timed


Notes/Equations
  1. This subnetwork performs EVM measurement on LTE uplink signal. The schematic of this subnetwork is shown in the following figure.
    Schematic of LTE_UL_EVM
  2. The QAM_Demod, TimedIQToCx and LTE_UL_Receiver function as the LTE uplink RF receiver, and LTE_UL_EVM_Sink performs the EVM measurement on the output signal from the LTE_UL_Receiver, which is the LTE uplink baseband receiver.
  3. The EVM is defined as the RMS value of the error vector difference between the ideal reference signal and the measured signal. Before calculating the EVM the measured waveform is corrected by the sample timing offset and RF frequency offset. Then the IQ origin offset shall be removed from the measured waveform. The measured waveform is further modified by selecting the absolute phase and absolute amplitude of the Tx chain. The EVM result is defined after the front-end IDFT as the square root of the ratio of the mean error vector power to the mean reference power expressed as a %. Its generic form can be written as follows:

    si: measured signal
    ri: ideal reference signal
  4. The basic EVM measurement interval is defined over one slot in the time domain. The formula described above is converted to

    where N is the number of data symbols within one slot.
  5. The accumulated average EVM is also provided, which is defined as follows:

    where M is the number of frames over which the averaging is performed which equals FramesToAverage.
  6. The EVM window of length W is centered
    • for bandwidths 15MHz and 20MHz, on the time interval determined by the measured cyclic prefix minus 16 samples of the considered SC-FDMA symbol for symbol 0 for normal CP, i.e. the first 16 samples of the CP should not be taken into account for this step; for other bandwidths, on the measured cyclic prefix of the considered SC-FDMA symbol for symbol 0 for normal CP.
    • on the measured cyclic prefix of the considered SC-FDMA symbol for symbol 1 to 6 for normal CP and for symbol 0 to 5 for extended CP.
  7. The EVM window length W affects the measured EVM, and is expressed as a function of the configured cyclic prefix length. Table F.5.3-1 and Table F.5.4-1 [1] specify the EVM window length at channel bandwidths 1.4, 3, 5, 10, 15,20MHz, for normal CP and extended CP respectively.
  8. The EVM requirements should be tested against the maximum of the RMS average at the window W extremities of the EVM measurements as defined in Section F.6 [1]. This is done in the dds LTE_UL_TxEVM.dds.
  9. If DisplayOption = Percentage, the EVM measurement results will be provided in percentage; if DisplayOption = dB, the EVM measurement results will be provided in dB; and if DisplayOption = Percentage_dB, the EVM measurement results in percentage and dB are both provided.
  10. If MeasurementOption = Per_PhysicalCh, the EVM measurement results for PUSCH on a slot basis is provided; If MeasurementOption = Per_Subcarrier, the EVM measurement results for PUSCH on each allocated subcarrier is provided; and if MeasurementOption = Per_PhysicalCh_Subcarrier, the EVM measurement results on each slot and occupied subcarrier are both provided.
  11. The constellation of the data symbols of the first frame is provided.
Parameter Details

RF Parameters Details:

System Parameters Details:

PUSCH Parameters Details:

PUCCH Parameters Details:

PRACH Parameters Details:

SRS Parameters Details:

Power Parameters Details:

Control Information Parameters Details:

Rx Algorithm Parameters Details:

EVM parameters Details:

  • FramesToAverage: number of frames that will be averaged.
  • DisplayOption: display option of the EVM measurement results, it can be selected as Percentage, dB and Percentage_dB.
  • MeasurementOption: option of EVM measurement, it can be selected as Per_PhysicalCh, Per_Subcarrier and Per_PhysicalCh_Subcarrier.
References
  1. 3GPP TS 36.101 v8.3.0, "User Equipments (UE) radio transmission and reception", Sept. 2008.
  2. 3GPP TS 36.211 v8.4.0, "Physical Channels and Modulation", Sept. 2008.
  3. TR 25.814 "Physical layer aspects for evolved Universal Terrestrial Radio Access (UTRA),", V7.0.0, June 2006.