Access Keys:
Skip to content (Access Key - 0)

Agilent Technologies

  

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.