lteTestModelTool

Generate downlink test model waveform

Syntax

lteTestModelTool

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

[waveform,grid,tm] = lteTestModelTool(tm)

Description

lteTestModelTool starts the LTE Waveform Generator app for the parameterization and generation of the E-UTRA test model (E-TM) waveforms.

[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.

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

Examples

Generate Downlink E-TM 2a Waveform

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 Downlink Waveform Using Full E-TM Configuration Structure

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 analyzer.

tmn = '3.2';
bw = '15MHz';
tmCfg = lteTestModel(tmn,bw);

[txWaveform,txGrid,tm] = lteTestModelTool(tmCfg);

saScope = dsp.SpectrumAnalyzer('SampleRate', tm.SamplingRate);
saScope(txWaveform)

Input Arguments

tmn — Test model number

'1.1' | '1.2' | '2' | '2a' | '2b' | '3.1' | '3.1a' | '3.1b' | '3.2' | '3.3'

Test model number, specified as a character vector or string scalar. Use double quotes for string. For more information on these test model numbers, see TS 36.141 [1], Section 6.1.

Example: '3.2'

Data Types: char | string

bw — Channel bandwidth

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

Channel bandwidth, specified as a character vector or string scalar. Use double quotes for string. 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 | string

ncellid — Physical layer cell identity

1 or 10 (default) | optional | integer

Physical layer cell identity, specified as an 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

duplexmode — Duplex mode of the generated waveform

'FDD' (default) | optional | 'TDD'

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

Example: 'FDD'

Data Types: char | string

tm — User-defined test model configuration

scalar structure

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

waveform — Generated E-TM time-domain waveform

numeric matrix

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

grid — Resource grid

2-D numeric array

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 Represent Resource Grids.

Data Types: double
Complex Number Support: Yes

tm — Test model configuration

scalar structure

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 Field	Values	Description
TMN	'1.1', '1.2', '2', '2a', '2b', '3.1', '3.1a', '3.1b' '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. ($$N_{\text{RB}}^{\text{DL}}$$)
CellRefP	1	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.
CFI	1, 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 0 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 Field	Values	Description
NLayers	1	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 one or two character vectors. Valid values of character vectors include: 'QPSK', '16QAM', '64QAM', '256QAM', '1024QAM'	Modulation formats, specifying the modulation formats for boosted and deboosted PRBs. This argument is for informational purposes and is read-only.

Data Types: struct

Compatibility Considerations

This function now opens the LTE Waveform Generator app

Behavior changed in R2019b

In previous releases, the input-free syntaxes of this function opened the LTE Test Model Generator app. Starting in R2019b, input-free calls to this function open the LTE Waveform Generator app for an E-TM waveform.

References

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

[2] 3GPP TS 36.211. “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network. URL: https://www.3gpp.org.