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lteTestModelTool

Downlink test model waveform generation

Syntax

  • [waveform,grid,tm] = lteTestModelTool
    example
  • [waveform,grid,tm] = lteTestModelTool(tmn,bw,ncellid,duplexmode)
    example
  • [waveform,grid,tm] = lteTestModelTool(tm)
    example

Description

example

[waveform,grid,tm] = lteTestModelTool starts a user interface for the parameterization and generation of the E-UTRA test model (E-TM) waveforms. The main function outputs can be configured in the user interface or assigned to variables in a function call. The E-TM time-domain waveform, plus associated resource element grid and test model configuration structure are output.

example

[waveform,grid,tm] = lteTestModelTool(tmn,bw,ncellid,duplexmode) accepts inputs for the test model number and channel bandwidth for the generated waveform. Optionally, accepts inputs for the physical cell identity and duplex mode.

example

[waveform,grid,tm] = lteTestModelTool(tm) where a user-defined test model configuration structure is provided as an input.

Examples

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lteTestModelTool

The LTE Downlink E-TM Generator user interface opens. Adjust settings and output varable names as desired.

After you click the Generate waveform button the specifed waveform, resource grid, and configuration variables will be available in the workspace.

Generate a time domain signal, txWaveform, and a 2-dimensional array of the Resource Elements, txGrid, for Test Model TS 36.141 E-TM 2a with 10MHz bandwidth. This is a 256QAM E-TM.

Specify test model number and bandwidth. Generate txWaveform. Plot the txGrid output.

[txWaveform,txGrid,tm] = lteTestModelTool('2a','10MHz');
plot(txGrid,'.')

The plot of all the complex resource element symbols in the frame is dominated by the 256QAM PDSCH constellation.

Generate a time domain signal, txWaveform, and a 2-dimensional array of the Resource Elements, txGrid, for Test Model TS 36.141 E-TM 3.2 with 15MHz bandwidth.

Specify test model number and bandwidth for tmCfg configuration structure and create it. Generate txWaveform. View the waveform with a spectrum anaylzer.

tmn = '3.2';
bw = '15MHz';
tmCfg = lteTestModel(tmn,bw);
[txWaveform,txGrid,tm] = lteTestModelTool(tmCfg);
saScope = dsp.SpectrumAnalyzer('SampleRate', tm.SamplingRate);
saScope(txWaveform)

Related Examples

Input Arguments

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Test model number, specified as a character vector. For more information on these test model numbers, see TS 36.141 [1], Section 6.1.

Example: '3.2'

Data Types: char

Channel bandwidth, specified as a character vector. You can set the nonstandard bandwidths, '9RB','11RB','27RB','45RB','64RB', and '91RB', only when tmn is '1.1'. These nonstandard bandwidths specify custom test models.

Example: '15MHz'

Data Types: char

Physical layer cell identity, specified as a integer. If you do not specify this argument, the default is 1 for standard bandwidths and 10 for non-standard bandwidths.

Example: 1

Data Types: double

Duplex mode of the generated waveform, specified as 'FDD' or 'TDD'. Optional.

Example: 'FDD'

Data Types: char

User-defined test model configuration, specified as a scalar structure. You can use lteTestModel to generate the various tm configuration structures as per TS 36.141, Section 6 [1]. This configuration structure then can be modified as per requirements and used to generate the waveform.

Data Types: struct

Output Arguments

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Generated E-TM time-domain waveform, returned as a T-by-P numeric matrix, where P is the number of antennas and T is the number of time-domain samples. TS 36.141 [1], Section 6 fixes P = 1, making waveform a T-by-1 column vector.

Data Types: double
Complex Number Support: Yes

Resource grid, returned as a 2-D numeric array of resource elements for a number of subframes across a single antenna port. The number of subframes (10 for FDD and 20 for TDD), start from subframe zero, across a single antenna port, as specified in TS 36.141 [1], Section 6.1. Resource grids are populated as described in Data Structures.

Data Types: double
Complex Number Support: Yes

E-UTRA test model (E-TM) configuration, returned as a scalar structure. tm contains the following fields.

Test model configuration, returned as a scalar structure containing information about the OFDM modulated waveform as described in lteOFDMInfo and test model specific configuration parameters as described in lteTestModel. These fields are included in the output structure:

Parameter FieldValuesDescription
TMN

'1.1', '1.2', '2', '2a', '3.1', '3.1a', '3.2', '3.3'

Test model number

BW

'1.4MHz', '3MHz', '5MHz', '10MHz', '15MHz', '20MHz', '9RB', '11RB', '27RB', '45RB', '64RB', '91RB',

Channel bandwidth type, in MHz, returned as a character vector. Non-standard bandwidths, '9RB', '11RB', '27RB', '45RB', '64RB', and '91RB', specify custom test models.

NDLRB

Nonnegative integer

Number of downlink resource blocks. (NRBDL)

CellRefP1

Number of cell-specific reference signal antenna ports. This argument is for informational purposes and is read-only.

NCellID

Integer from 0 to 503

Physical layer cell identity

CyclicPrefix'Normal'

Cyclic prefix length. This argument is for informational purposes and is read-only.

CFI1, 2, or 3

Control format indicator value

Ng

'Sixth', 'Half', 'One', 'Two'

HICH group multiplier

PHICHDuration

'Normal', 'Extended'

PHICH duration

NSubframe

0 (default), nonnegative scalar integer

Subframe number

This argument is for informational purposes and is read-only.
TotSubframes

Nonnegative scalar integer

Total number of subframes to generate

Windowing

Nonnegative scalar integer

Number of time-domain samples over which windowing and overlapping of OFDM symbols is applied

DuplexMode

'FDD' (default), 'TDD'

Duplexing mode, specified as:

  • 'FDD' for Frequency Division Duplex or

  • 'TDD' for Time Division Duplex

CellRSPower

Numeric value

Cell-specific reference symbol power adjustment, in dB

PDSCH

Scalar structure

PDSCH transmission configuration substructure

PSSPower

Numeric value

Primary synchronization signal (PSS) symbol power adjustment, in dB

SSSPower

Numeric value

Secondary synchronization signal (SSS) symbol power adjustment, in dB

PBCHPower

Numeric value

PBCH symbol power adjustment, in dB

PCFICHPower

Numeric value

PCFICH symbol power adjustment, in dB

NAllocatedPDCCHREG

Nonnegative integer

Number of allocated PDCCH REGs. This argument is derived from tmn and bw.

PDCCHPower

Numeric value

PDCCH symbol power adjustment, in dB

PDSCHPowerBoosted

Numeric value

PDSCH symbol power adjustment, in dB, for the boosted physical resource blocks (PRBs)

PDSCHPowerDeboosted

Numeric value

PDSCH symbol power adjustment, in dB, for the de-boosted physical resource blocks (PRBs)

These fields are present only when DuplexMode is set to 'TDD'.
SSC

Integer from 1 to 9

8 (default)

Special subframe configuration (SSC)

SSC enumerates the special subframe configuration. TS 36.211 [2], Section 4.2 specifies the special subframe configurations (lengths of DwPTS, GP, and UpPTS).

TDDConfig

Integer from 1 to 6

3 (default)

Uplink–downlink configuration

TDDConfig enumerates the subframe uplink-downlink configuration to be used in this frame. TS 36.211 [2], Section 4.2 specifies uplink-downlink configurations (uplink, downlink, and special subframe combinations).

AllocatedPRB

Numeric array

Allocated physical resource block list

SamplingRate

Numeric value

Sampling rate of the time-domain waveform

Nfft

Positive integer

Number of fast Fourier transform (FFT) points

PDSCH substructure

The substructure PDSCH relates to the physical channel configuration and contains these fields:

Parameter FieldValuesDescription
NLayers1

Number of transmission layers, returned as 1. This argument is for informational purposes and is read-only.

TxScheme'Port0'

Transmission scheme. The E-TMs have a single antenna port. This argument is for informational purposes and is read-only.

Modulation

Cell array of these one or two character vectors.

('QPSK', '16QAM', '64QAM', '256QAM')

Modulation formats, specifying the modulation formats for boosted and deboosted PRBs. This argument is for informational purposes and is read-only.

Data Types: struct

References

[1] 3GPP TS 36.141. "Base Station (BS) conformance testing." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA). URL: http://www.3gpp.org.

[2] 3GPP TS 36.211. "Physical channels and modulation." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA). URL: http://www.3gpp.org.

Introduced in R2014a

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