info

Provide dimensioning information for OFDM modulator

Description

example

infostruct = info(ofdmmod) returns the input, pilot, and output data dimensions for the specified OFDM modulator System object™.

Examples

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Determine the OFDM modulator data dimensions by using the info method.

Construct an OFDM modulator System object™ with user-specified pilot indices, insert a DC null, and specify two transmit antennas.

hMod = comm.OFDMModulator('NumGuardBandCarriers',[4;3], ...
    'PilotInputPort',true, ...
    'PilotCarrierIndices',cat(3,[12; 26; 40; 54], ...
    [11; 25; 39; 53]), ...
    'InsertDCNull',true, ...
    'NumTransmitAntennas',2);

Use the info method to find the modulator input data, pilot input data, and output data sizes.

info(hMod)
ans = struct with fields:
     DataInputSize: [48 1 2]
    PilotInputSize: [4 1 2]
        OutputSize: [80 2]

Input Arguments

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OFDM modulator, specified as a comm.OFDMModulator System object.

Output Arguments

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Dimensions of structure for OFDM modulator, returned as a structure containing these fields.

System object.

Dimensions of input data, returned as a 3-D array of numeric values. The dimensions of this field are Ndata-by-Nsym, where Ndata is the number of data subcarriers such that Ndata = NFFTNleftGNrightGNDCNullNpilotNcustNull.

For variable definitions, see Variable Definitions.

Dimensions of the pilot input array, returned as a 3-D array of numeric values. The output dimensions of this field are Npilot-by-Nsym-by-Nt.

Dimensions of the modulator output data, returned as a 3-D array of numeric values. The dimensions of this field are ((NFFT + NCPNsym)-by-Nt.

For variable definitions, see Variable Definitions.

Data Types: struct

More About

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List of Variables

The variables mentioned in this table are defined in this table:

Variable Definitions

VariableDescription
NFFTNumber of subcarriers
NleftGNumber of subcarriers in the left guard band
NrightGNumber of subcarriers in the right guard band
NDCNullNumber of subcarriers in the DC null (either 0 or 1)
NpilotNumber of pilot subcarriers
NcustNullNumber of subcarriers used for custom nulls (applies only when the PilotCarrierIndices property of input ofdmmod is a 3-D array)
NtNumber of transmit antennas
NCPLength of cyclic prefix.

See Also

Functions

Objects

Introduced in R2014a