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3GPPFDD_EVM_NonSyn



Description: 3GPP FDD EVM measurement
Library: 3GPPFDD, Measurement
Class: SDF3GPPFDD_EVM_NonSyn
Derived From: 3GPPFDD_MeasBase

Parameters

Name

Description

Default

Unit

Type

Range

SpecVersion

version of specifications: Version_03_00, Version_12_00, Version_03_02

Version_12_00

 

enum

 

LinkDir

link direction: Downlink, Uplink

Uplink

 

enum

 

SlotFormat

slot format

0

 

int

ScrambleCode

index of scramble code

0

 

int

[0:512] for downlink;
[0, 16777215] for uplink

Scramble

scramble code type: LONG, SHORT

LONG

 

enum

 

ScrambleOffset

scramble code offset

0

 

int

[0:15]

ScrambleType

scramble code type: normal, right, left

normal

 

enum

 

SpreadCode

index of spread code

0

 

int

[0:SF-1];
SF can be set by SlotFormat or equal to SpreadFactor;
SF is 256 if for CPICH, PICH or uplink DPCCH

SampleRate

sample rate

8

 

int

[1:256]

StartSlot

number of slot to be ignored

0

 

int

[0, ∞)

SlotNum

slot number

1

 

int

[1:15]

Correlator

correlator method: Coherent, NonCoherent

Coherent

 

enum

 

SCH

switch for SCH: SCH_On, SCH_Off

SCH_On

 

enum

 

CPICH

switch for CPICH: CPICH_On, CPICH_Off

CPICH_Off

 

enum

 

EVMValue

EVM value expression options: EVM_Ratio, EVM_Percent

EVM_Percent

 

enum

 

Correct_IQ_Offset

switch for IQ offset correction: Yes, No

Yes

 

enum

 

DUT_DelayBound

DUT delay bound

.00001 sec

sec

real

[0:(400.0/3840000)]

† [0:5] for uplink DPCCH;

[0:16] for downlink DPCH;

[0:17] for downlink SCCPCH;

[0:5] for uplink PCPCH (Ver 03_00);

[0:2] for uplink PCPCH (Ver 12_00);

[0:1] for uplink PCPCH (Ver 03_02);

Uplink DPCCH spread factor is 256;

Spread Factor is 512 when down link DPCH SlotFormat is 0 and 1;

Spread Factor is 256 when down link DPCH SlotFormat is 2, 3, 4, 5, 6, and 7;

Spread Factor is 128 when down link DPCH SlotFormat is 8, 9, 10, and 11;

Spread Factor is 64 when down link DPCH SlotFormat is 12;

Spread Factor is 32 when down link DPCH SlotFormat is 13;

Spread Factor is 16 when down link DPCH SlotFormat is 14;

Spread Factor is 8 when down link DPCH SlotFormat is 15;

Spread Factor is 4 when down link DPCH SlotFormat is 16;

Pin Inputs

Pin

Name

Description

Signal Type

1

test

tested signals

complex

2

ref

reference signals

complex

Notes/Equations
  1. This subnetwork model measures EVM that is used to evaluate modulation accuracy. The schematic for this subnetwork is shown in the following figure.

    3GPPFDD_EVM_NonSyn Schematic
    In the 2003C release, 3GPPFDD_EVM_NonSyn provides a new method for EVM measurement compared to 3GPPFDD_EVM.
    To measure EVM, the reference signal and test signal must be fully time-aligned. 3GPPFDD_EVM reference and test signals are synchronized using the spreading code. Because the EVM value relies on the synchronization performance, if the test signal is severely impaired the EVM calculation may be erroneous.
    3GPPFDD_EVM_NonSyn uses the spreading code to synchronize the reference signals only. The noise-free reference signal can be accurately aligned at the slot boundary.
    The EVM is calculated by probing the minimum differences between the reference signals (aligned at slot boundary) and test signals (not aligned at slot boundary) over a window size that is determined by DUT_DelayBound. The EVM is the minimum when the test and reference signals are fully aligned.
    This method is very robust against impairments imposed on test signals. The simulation time is linearly proportional to the EVM probing window size (determined by DUT_DelayBound). The simulation time is approximately 30 seconds for a window size of 128, in a P4/1.7G 512M PC (powered by ADS 2003C and MS Windows 2000).
  2. The 3GPP system chip rate is 3.84 Mcps. The BS_Tx_EVM.dsn design demonstrates the use of this model in File > Example Project > WCDMA3G > WCDMA3G_BS_Tx_prj; this project is discussed in Base Station Transmitter Design Examples.

References
  1. 3GPP Technical Specification TS 34.121 V3.8.0, Terminal Conformance Specification, Radio Transmission and Reception (FDD), March 2003, Release 1999.

    http://www.3gpp.org/ftp/Specs/2002-03/R1999/34_series/34121-380.zip

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