Fetches the physical downlink shared channel (PDSCH) EVMs.
Use "carrier<k>" or "subblock<n>/carrier<k>" as the selector string to read results from this function.

Syntax

int32 __stdcall RFmxLTE_ModAccFetchPDSCHEVM(niRFmxInstrHandle instrumentHandle, char selectorString[], float64 timeout, float64 *meanRMSEVM, float64 *meanRMSQPSKEVM, float64 *meanRms16QAMEVM, float64 *meanRms64QAMEVM, float64 *meanRms256QAMEVM)

Parameters

NameDirectionTypeDescription
instrumentHandle[in]niRFmxInstrHandle

This parameter specifies the RFmx session refnum. Instrument Handle In is obtained from the RFmxInstr_Initialize function.

selectorString[in]char

This parameter specifies a Selector String comprising of the signal name, result name, subblock number, and carrier number. If you do not specify the signal name, the default signal instance is used. If you do not specify the result name, the default result instance is used. The default value is "subblock0/carrier0".
Example:
"subblock0/carrier0"
"signal::sig1/subblock0/carrier0"
"result::r1/subblock0/carrier0"
"signal::sig1/result::r1/subblock0/carrier0"
You can use the RFmxLTE Build Carrier String function to build the selector string.

timeout[in]float64

This parameter specifies the timeout for fetching the specified measurement. This value is expressed in seconds. Set this value to an appropriate time, longer than expected for fetching the measurement. A value of -1 specifies that the function waits until the measurement is complete. The default value is 10.

meanRMSEVM[out]float64 *

This parameter returns the mean value of RMS EVMs calculated on PDSCH data symbols over the slots specified by the RFMXLTE_ATTR_MODACC_MEASUREMENT_LENGTH attribute. When you set the RFMXLTE_ATTR_MODACC_EVM_UNIT attribute to Percentage, the measurement is returned in percentage. When you set the ModAcc EVM Unit attribute to dB, the measurement is returned in dB.

meanRMSQPSKEVM[out]float64 *

This parameter returns the mean value of RMS EVMs calculated on all QPSK modulated PDSCH resource blocks over the slots specified by the ModAcc Meas Length attribute. When you set the ModAcc EVM Unit attribute to Percentage, the measurement is returned in percentage. When you set the ModAcc EVM Unit attribute to dB, the measurement is returned in dB.

meanRms16QAMEVM[out]float64 *

This parameter returns the mean value of RMS EVMs calculated on all 16QAM modulated PDSCH resource blocks over the slots specified by the ModAcc Meas Length attribute. When you set the ModAcc EVM Unit attribute to Percentage, the measurement is returned in percentage. When you set the ModAcc EVM Unit attribute to dB, the measurement is returned in dB.

meanRms64QAMEVM[out]float64 *

This parameter returns the mean value of RMS EVMs calculated on all 64QAM modulated PDSCH resource blocks over the slots specified by the ModAcc Meas Length attribute. When you set the ModAcc EVM Unit attribute to Percentage, the measurement is returned in percentage. When you set the ModAcc EVM Unit attribute to dB, the measurement is returned in dB.

meanRms256QAMEVM[out]float64 *

This parameter returns the mean value of RMS EVMs calculated on all 256QAM modulated PDSCH resource blocks over the slots specified by the ModAcc Meas Length attribute. When you set the ModAcc EVM Unit attribute to Percentage, the measurement is returned in percentage. When you set the ModAcc EVM Unit attribute to dB, the measurement is returned in dB.

Returns

Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. Examine the status code from each call to an RFmx function to determine if an error has occurred.

To obtain a text description of the status code and additional information about the error condition, call the RFmxLTE_GetError function.

The general meaning of the status code is as follows:

Value

Meaning

0

Success

Positive Values

Warnings

Negative Values

Errors