RFmxLTE_ModAccFetchEVMLowPerSymbolTrace
- Updated2024-10-14
- 2 minute(s) read
RFmxLTE_ModAccFetchEVMLowPerSymbolTrace
int32 __stdcall RFmxLTE_ModAccFetchEVMLowPerSymbolTrace (niRFmxInstrHandle instrumentHandle, char selectorString[], float64 timeout, float64* x0, float64* dx, float32 EVMLowPerSymbol[], int32 arraySize, int32* actualArraySize);
Purpose
Returns the EVM per symbol trace for all the configured slots. The EVM is obtained by using FFT window position, Delta_C-W/2.
Refer to the LTE Modulation Accuracy (ModAcc) topic for more information.
Use "carrier<k>" or "subblock<n>/carrier<k>" as the selector string to read results from this function.
Parameters
| Input | ||
| Name | Type | Description |
| instrumentHandle | niRFmxInstrHandle | Specifies the instrument session. The RFmx obtains this parameter from the RFmxLTE_Initialize function. |
| selectorString | char[] | 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. Example: "subblock0/carrier0" "signal::sig1/subblock0/carrier0" "result::r1/subblock0/carrier0" "signal::sig1/result::r1/subblock0/carrier0" You can use the RFmxLTE_BuildCarrierString function to build the selector string. |
| timeout | float64 | Specifies the timeout, in seconds, for fetching the specified measurement. 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. |
| arraySize | int32 | Specifies the size of the array. Set the arraySize parameter to 0 to get the size of all the arrays in the actualArraySize parameter. |
| Output | ||
| Name | Type | Description |
| x0 | float64* | Returns the starting OFDM symbol position corresponding to the
RFMXLTE_ATTR_MODACC_MEASUREMENT_OFFSET attribute.
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| dx | float64* | Returns 1 as the value.
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| EVMLowPerSymbol | float32[] | Returns the array of the EVM per symbol trace for all the configured slots. The EVM is obtained by using FFT window position, Delta_C-W/2.
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| actualArraySize | int32* | Returns the actual size of the array, if you pass NULL to all output array parameters, and set the arraySize parameter to 0. |
Return Value
| Name | Type | Description | ||||||||
| status | int32 | 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:
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