Documentation

## Generate LTE Downlink RMC Waveforms

### LTE Downlink RMC Generator Overview

You can use the LTE Downlink RMC Generator app to generate downlink reference measurement channel (RMC) waveforms.

### Open LTE Downlink RMC Generator App

To open the LTE Downlink RMC Generator app, select the APPS tab on the MATLAB desktop and click the following icon.

Alternatively, the LTE Downlink RMC Generator app can be launched from the MATLAB® command window.

### Open LTE Downlink RMC Generator App from Command Line

The LTE Downlink RMC Generator dialog box appears when you execute lteDownlinkRMCGenerator or lteRMCDLTool with no input arguments.

Use this interface to generate the default waveform or adjust default settings prior to waveform generation

### Dialog Box Inputs and Outputs

#### Parameters

In the LTE Downlink RMC Generator dialog box, you can set the following parameters.

Parameter (Equivalent Field)ValuesDescription
Reference channel (RC)

'R.0' (default), 'R.1', 'R.2', 'R.3', 'R.4', 'R.5', 'R.6', 'R.7', 'R.8', 'R.9', 'R.10', 'R.11', 'R.12', 'R.13', 'R.14', 'R.25', 'R.26', 'R.27', 'R.28', 'R.31-3A', 'R.31-4', 'R.43', 'R.44', 'R.45', 'R.45-1', 'R.48', 'R.50', 'R.51', 'R.6-27RB', 'R.12-9RB', 'R.11-45RB'

Reference measurement channel (RMC) number or type, as specified in TS 36.101, Annex A.3.

• To facilitate the transmission of system information blocks (SIB), normally no user data is scheduled on subframe 5. However, 'R.31-3A' and 'R.31-4' are sustained data rate RMCs and have user data in subframe 5.

• 'R.6-27RB', 'R.12-9RB', and 'R.11-45RB' are custom RMCs configured for non-standard bandwidths that maintain the same code rate as the standardized versions defined in TS 36.101, Annex A.3.

The 'R6-27RB', 'R12-9RB', and 'R11-45RB' RC values are custom RMC configured for nonstandard bandwidths, but with the same code rate as the standardized versions.

Duplex mode (DuplexMode)

'FDD' (default), 'TDD'

Duplexing mode, specified as:

• 'FDD' for Frequency Division Duplex or

• 'TDD' for Time Division Duplex

Transmission scheme (TxScheme)

'Port0', 'TxDiversity', 'CDD', 'SpatialMux', 'MultiUser', 'Port5', 'Port7-8', 'Port8', 'Port7-14'.

PDSCH transmission scheme, specified as one of the following options.

Transmission schemeDescription
'Port0'Single antenna port, port 0
'TxDiversity'Transmit diversity
'CDD'Large delay cyclic delay diversity scheme
'SpatialMux'Closed loop spatial multiplexing
'MultiUser'Multi-user MIMO
'Port5'Single-antenna port, port 5
'Port7-8'Single-antenna port, port 7, when NLayers = 1. Dual layer transmission, ports 7 and 8, when NLayers = 2.
'Port8'Single-antenna port, port 8
'Port7-14'Up to eight layer transmission, ports 7–14

Cell identity (NCellID)

Integer from 0 to 503

Physical layer cell identity

RNTI (RNTI)

0 (default), scalar integer

Radio network temporary identifier (RNTI) value (16 bits)

RV sequence (RVSeq)

Integer vector (0,1,2,3), specified as a one or two row matrix (for one or two codewords)

Specifies the sequence of Redundancy Version (RV) indicators for each HARQ process. The number of elements in each row is equal to the number of transmissions in each HARQ process. If RVSeq is a row vector in a two codeword transmission, then the same RV sequence is applied to both codewords.

Rho (dB) (Rho)

0 (default), Numeric scalar

PDSCH resource element power allocation, in dB

OCNG (OCNG)

'Off', 'On'. 'Disable' and 'Enable' are also accepted.

OFDMA channel noise generator

Number of subframes (TotSubframes)

Nonnegative scalar integer

Total number of subframes to generate

Number of codewords (NCodewords)

1, 2

Number of PDSCH codewords to use in PDSCH transmission

PMI set (PMISet)

Integer vector with element values from 0 to 15.

Precoder matrix indication (PMI) set. It can contain either a single value, corresponding to single PMI mode, or multiple values, corresponding to multiple or subband PMI mode. The number of values depends on CellRefP, transmission layers and TxScheme. For more information about setting PMI parameters, see ltePMIInfo.

Number of HARQ processes (NHARQProcesses)

1, 2, 3, 4, 5, 6, 7, or 8

Number of HARQ processes per component carrier

Windowing (samples) (Windowing)

Nonnegative scalar integer

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

Waveform output variable

Variable name, beginning with an alphabetical character and containing alphanumeric characters

Waveform output variable name. When you click , a new variable with this name is created in the MATLAB workspace.

Resource grid output variable

Variable name, beginning with an alphabetical character and containing alphanumeric characters

Resource grid output variable name. When you click , a new variable with this name is created in the MATLAB workspace.

RMC configuration output variable

Variable name, beginning with an alphabetical character and containing alphanumeric characters

RMC configuration output parameter structure name. When you click , a new variable with this name is created in the MATLAB workspace.

#### RMC Parameter Summary

The LTE Downlink RMC Generator dialog box displays the following RMC parameters.

Parameter (Equivalent Field)ValuesDescription
Number of downlink resource blocks (NDLRB)

Scalar integer from 6 to 110

Number of downlink resource blocks. (${N}_{\text{RB}}^{\text{DL}}$)

Transmit antenna ports (CellRefP)

1, 2, 4

Number of cell-specific reference signal (CRS) antenna ports

Modulation (Modulation)

'QPSK', '16QAM', '64QAM'

Modulation type

Transmission layers (NLayers)

1 (default), 2, 3, 4, 5, 6, 7, 8

Number of transmission layers.

Total info bits per frame per codeword

Positive scalar integer

Total transport block capacity per frame per codeword

#### Codeword Input Data

In the LTE Downlink RMC Generator dialog box, you can set the following input data for codewords. These input data are equivalent to elements of the trdata cell array in the lteRMCDLTool function.

Input DataValuesDescription
Transport info bit stream (codeword 1)

User defined, External file

Information bits to transmit on PDSCH for codeword 1.

Transport info bit stream (codeword 2)

User defined, External file

Information bits to transmit on PDSCH for codeword 2.

For each input, you can select one of the following options from the drop-down menu.

• User defined — Select this option to specify the information bits as a vector of zeros and ones or a variable name. Either enter in the vector manually, or specify the name of an existing variable in the MATLAB workspace. Each vector contains the information bits stream to be coded across the duration of the generation, which represents multiple concatenated transport blocks. Internally, these vectors are looped if the number of bits required across all subframes of the generation exceeds the length of the vectors provided. This feature allows you to enter a short pattern, such as [1;0;0;1], that is repeated as the input to the transport coding.

• External file — Select this option to specify a MAT-file in which the variable that you want to use as input data is stored. When you click , the Select Files dialog box opens. Select the file that contains the input data, and click . The Import Wizard dialog box opens. Select the variable in this file that contains the information bits, and click .

### Examples

#### Generate RMC R.12 Waveform

This example shows how to generate a time-domain signal, waveform, and a 3-D array of the resource elements, grid, for the RMC R.12, as specified in TS 36.101.

Open the LTE Downlink RMC Generator app. Select the APPS tab on the MATLAB desktop and click the following icon.

The LTE Downlink RMC Generator dialog box opens.

From the RC drop-down list, choose R.12.

For Waveform output variable, enter waveform.

For Resource grid output variable, enter grid.

For RMC configuration output variable, enter rmcCfg. The dialog box now appears as shown in the following figure.

Click the button. The variables waveform, grid, and rmcCfg now appear in the MATLAB Workspace Browser.

## References

[1] 3GPP TS 36.101. “User Equipment (UE) Radio Transmission and Reception.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA). URL: http://www.3gpp.org.