QevmResults

Provides methods to fetch and read the Qevm measurement results.

class nirfmxwcdma.qevm_results.QevmResults(signal_obj)[source]

Bases: object

Provides methods to fetch and read the Qevm measurement results.

fetch_constellation_trace(selector_string, timeout, constellation)[source]

Fetches the complex chips of the composite corrected signal for the QEVM measurement.

Parameters:

selector_string (string) –
This parameter specifies a Selector String comprising of the signal name and result name.

Example:

”result::r1”

You can use the build_result_string() method to build the selector string.
timeout (float) – This parameter specifies the time for which the method waits for the measurement to complete. This value is expressed in seconds. A value of -1 specifies that the method waits until the measurement is complete. The default value is 10.
constellation (numpy.complex64) – This parameter returns an array of complex chips of the QPSK corrected signal for the last acquisition. You can use these chips to obtain the constellation diagram.

Returns:

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

int

fetch_evm(selector_string, timeout)[source]

Fetches the mean chip rate error, mean frequency error, mean RMS EVM, maximum peak EVM, mean magnitude error, and mean phase error of the complex chips of the corrected signal for the QEVM measurement.

Parameters:

selector_string (string) –
This parameter specifies a Selector String comprising of result name.

Example:

”result::r1”

You can use the build_result_string() method to build the selector string.
timeout (float) – This parameter specifies the time for which the method waits for the measurement to complete. This value is expressed in seconds. A value of -1 specifies that the method waits until the measurement is complete. The default value is 10.

Returns:

mean_rms_evm (float):

This parameter returns the mean of the RMS EVM values for a QPSK signal. This value is obtained by averaging the RMS EVMs over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute. This value is expressed as a percentage.

The EVM of a chip is the magnitude of the vector difference between the received chip and the ideal chip. The RMS EVM is obtained from all the chips in the measurement interval.

maximum_peak_evm (float):

This parameter returns the maximum value of the peak EVMs for a QPSK signal. This value is expressed as a percentage. This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The EVM of a chip is the magnitude of the vector difference between the received chip and the ideal chip. The peak EVM is obtained from all the chips in the measurement interval.

mean_frequency_error (float):

This parameter returns the mean of the frequency errors for a QPSK signal. This value is expressed in Hz. This value is obtained by the mean of frequency errors obtained over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The frequency error is the estimated difference between the carrier frequency of the received signal and the ideal signal.

mean_magnitude_error (float):

This parameter returns the mean of RMS magnitude errors for a QPSK signal. This value is expressed as a percentage. This value is obtained by averaging the RMS magnitude errors over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The magnitude error of a chip is the difference in the magnitudes of the received chip and the ideal chip. The RMS magnitude error is obtained from all the chips in the measurement interval.

mean_phase_error (float):

This parameter returns the mean of the RMS phase error values for a QPSK signal. This value is expressed as a percentage. This value is obtained by averaging the RMS phase errors obtained over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The phase error of a chip is the difference in the phases of the received chip and the ideal chip. The RMS phase error is obtained from all the chips in the measurement interval.

mean_chip_rate_error (float):

This parameter returns the mean of the chip rate errors for a QPSK signal. This value is expressed in ppm. This value is obtained by averaging the chip rate errors over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The chip rate error is the estimated error between the chip clock rate of the transmitted signal and the chip clock rate at the receiver.

error_code (int):

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (mean_rms_evm, maximum_peak_evm, mean_frequency_error, mean_magnitude_error, mean_phase_error, mean_chip_rate_error, error_code)

fetch_evm_trace(selector_string, timeout, evm)[source]

Fetches the EVM trace for the QEVM measurement.

Parameters:

selector_string (string) –
This parameter specifies a Selector String comprising of the signal name and result name.

Example:

”result::r1”

You can use the build_result_string() method to build the selector string.
timeout (float) – This parameter specifies the time for which the method waits for the measurement to complete. This value is expressed in seconds. A value of -1 specifies that the method waits until the measurement is complete. The default value is 10.
evm (numpy.float32) – This parameter returns the EVM value. This value is expressed as a percentage.

Returns:

x0 (float):: This parameter returns the start time. This value is expressed in seconds.
dx (float):: This parameter returns the chip duration. This value is expressed in seconds.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (x0, dx, error_code)

fetch_iq_impairments(selector_string, timeout)[source]

Fetches the mean and maximum I/Q origin offsets, I/Q gain imbalances, and I/Q quadrature errors for the QEVM measurement.

Parameters:

selector_string (string) –
This parameter specifies a Selector String comprising of the signal name and result name.

Example:

”result::r1”

You can use the build_result_string() method to build the selector string.
timeout (float) – This parameter specifies the time for which the method waits for the measurement to complete. This value is expressed in seconds. A value of -1 specifies that the method waits until the measurement is complete. The default value is 10.

Returns:

mean_iq_origin_offset (float):

This parameter returns the mean of I/Q origin offsets for a QPSK signal. This value is expressed in dB. This value is obtained by averaging the I/Q origin offsets over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The I/Q origin offset is a measure of the DC component present in the I/Q signal being measured.

mean_iq_gain_imbalance (float):

This parameter returns the mean of the I/Q gain imbalances for a QPSK signal. This value is expressed in dB. This value is obtained by the I/Q gain imbalances obtained over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute. The I/Q gain imbalance is the ratio of the magnitude of the I component to the Q component of the I/Q signal being measured. This result is for future use.

mean_iq_quadrature_error (float):

This parameter returns the mean of the I/Q quadrature errors for a QPSK signal. This value is expressed in degrees. This value is obtained by the mean of I/Q quadrature errors obtained over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute. Quadrature error is a measure of the error in the phase between I and Q components of the signal being measured. This result is for future use.

maximum_iq_origin_offset (float):

This parameter returns the maximum I/Q origin offset for a QPSK signal. This value is expressed in dB.

maximum_iq_gain_imbalance (float):

This parameter returns the maximum value of I/Q gain imbalances for a QPSK signal. This value is expressed in dB. This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The I/Q gain imbalance is the ratio of the magnitude of the I component to the Q component of the I/Q signal being measured. This result is for future use.

maximum_iq_quadrature_error (float):

This parameter returns the maximum value of I/Q quadrature errors for a QPSK signal. This value is expressed in degrees. This value is obtained over all averaging iterations.

The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

Quadrature error is a measure of the error in the phase between I and Q components of the signal being measured. This result is for future use.

error_code (int):

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (mean_iq_origin_offset, mean_iq_gain_imbalance, mean_iq_quadrature_error, maximum_iq_origin_offset, maximum_iq_gain_imbalance, maximum_iq_quadrature_error, error_code)

fetch_magnitude_error_trace(selector_string, timeout, magnitude_error)[source]

Fetches the magnitude error trace for the QEVM measurement.

Parameters:

selector_string (string) –
This parameter specifies a Selector String comprising of the signal name and result name.

Example:

”result::r1”

You can use the build_result_string() method to build the selector string.
timeout (float) – This parameter specifies the time for which the method waits for the measurement to complete. This value is expressed in seconds. A value of -1 specifies that the method waits until the measurement is complete. The default value is 10.
magnitude_error (numpy.float32) – This parameter returns the magnitude error values. This value is expressed as a percentage.

Returns:

x0 (float):: This parameter returns the start time. This value is expressed in seconds.
dx (float):: This parameter returns the chip duration. This value is expressed in seconds.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (x0, dx, error_code)

fetch_phase_error_trace(selector_string, timeout, phase_error)[source]

Fetches the phase error trace for the QEVM measurement.

Parameters:

selector_string (string) –
This parameter specifies a Selector String comprising of the signal name and result name.

Example:

”result::r1”

You can use the build_result_string() method to build the selector string.
timeout (float) – This parameter specifies the time for which the method waits for the measurement to complete. This value is expressed in seconds. A value of -1 specifies that the method waits until the measurement is complete. The default value is 10.
phase_error (numpy.float32) – This parameter returns an array of phase error values. This value is expressed in degrees.

Returns:

x0 (float):: This parameter returns the start time. This value is expressed in seconds.
dx (float):: This parameter returns the chip duration. This value is expressed in seconds.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (x0, dx, error_code)

get_maximum_chip_rate_error(selector_string)[source]

Gets the maximum chip rate error value for a QPSK signal. This value is expressed in ppm. This value is obtained over all averaging iterations. The number of acquisitions is specified by the QEVM_AVERAGING_COUNT attribute.

The chip rate error is the estimated error between the chip clock rate of the transmitted signal and the chip clock rate at the receiver.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the maximum chip rate error value for a QPSK signal. This value is expressed in ppm. This value is obtained over all averaging iterations. The number of acquisitions is specified by the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_maximum_frequency_error(selector_string)[source]

Gets the maximum value of the frequency errors for a QPSK signal. This value is expressed in Hz. This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The frequency error is the estimated difference between the carrier frequency of the received signal and the ideal signal.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the maximum value of the frequency errors for a QPSK signal. This value is expressed in Hz. This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_maximum_iq_origin_offset(selector_string)[source]

Gets the maximum value of the I/Q origin offsets for a QPSK signal. This value is expressed in dB.

This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The I/Q Origin Offset is the amount of DC component present in the I/Q signal being measured.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the maximum value of the I/Q origin offsets for a QPSK signal. This value is expressed in dB.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_maximum_magnitude_error(selector_string)[source]

Gets the maximum value of the RMS magnitude errors for a QPSK signal. This value is expressed as a percentage. This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The magnitude error of a chip is the difference in the magnitudes of the received chip and the ideal chip. The RMS magnitude error is obtained from all the chips in the measurement interval.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the maximum value of the RMS magnitude errors for a QPSK signal. This value is expressed as a percentage. This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_maximum_peak_evm(selector_string)[source]

Gets the maximum value of the peak EVMs for a QPSK signal. This value is expressed as a percentage. This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The EVM of a chip is the magnitude of the vector difference between the received chip and the ideal chip. The peak EVM is obtained from all the chips in the measurement interval.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the maximum value of the peak EVMs for a QPSK signal. This value is expressed as a percentage. This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_maximum_phase_error(selector_string)[source]

Gets the maximum value of the RMS phase errors for a QPSK signal. This value is expressed in degrees. This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The phase error of a chip is the difference in the phases of the received chip and the ideal chip. The RMS phase error is obtained from all the chips in the measurement interval.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the maximum value of the RMS phase errors for a QPSK signal. This value is expressed in degrees. This value is obtained over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_maximum_rms_evm(selector_string)[source]

Gets the maximum value of the RMS EVMs for a QPSK signal. This value is expressed as a percentage. This value is obtained over all averaging iterations.

The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The EVM of a chip is the magnitude of the vector difference between the received chip and the ideal chip. The RMS EVM is obtained from all the chips in the measurement interval.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the maximum value of the RMS EVMs for a QPSK signal. This value is expressed as a percentage. This value is obtained over all averaging iterations.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_mean_chip_rate_error(selector_string)[source]

Gets the mean of the chip rate errors for a QPSK signal. This value is expressed in ppm. This value is obtained by averaging the chip rate errors over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The chip rate error is the estimated error between the chip clock rate of the transmitted signal and the chip clock rate at the receiver.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the mean of the chip rate errors for a QPSK signal. This value is expressed in ppm. This value is obtained by averaging the chip rate errors over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_mean_frequency_error(selector_string)[source]

Gets the mean of the frequency errors for a QPSK signal. This value is expressed in Hz. This value is obtained by the mean of frequency errors obtained over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The frequency error is the estimated difference between the carrier frequency of the received signal and the ideal signal.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the mean of the frequency errors for a QPSK signal. This value is expressed in Hz. This value is obtained by the mean of frequency errors obtained over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_mean_iq_origin_offset(selector_string)[source]

Gets the mean of I/Q origin offsets for a QPSK signal. This value is expressed in dB. This value is obtained by averaging the I/Q origin offsets over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The I/Q origin offset is a measure of the DC component present in the I/Q signal being measured.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the mean of I/Q origin offsets for a QPSK signal. This value is expressed in dB. This value is obtained by averaging the I/Q origin offsets over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_mean_magnitude_error(selector_string)[source]

Gets the mean of RMS magnitude errors for a QPSK signal. This value is expressed as a percentage. This value is obtained by averaging the RMS magnitude errors over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The magnitude error of a chip is the difference in the magnitudes of the received chip and the ideal chip. The RMS magnitude error is obtained from all the chips in the measurement interval.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the mean of RMS magnitude errors for a QPSK signal. This value is expressed as a percentage. This value is obtained by averaging the RMS magnitude errors over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_mean_peak_evm(selector_string)[source]

Gets the mean of peak EVMs for a QPSK signal. This value is expressed as a percentage. This value is obtained by averaging the peak EVMs over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The EVM of a chip is the magnitude of the vector difference between the received chip and the ideal chip. The peak EVM is obtained from all the chips in the measurement interval.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the mean of peak EVMs for a QPSK signal. This value is expressed as a percentage. This value is obtained by averaging the peak EVMs over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_mean_phase_error(selector_string)[source]

Gets the mean of the RMS phase error values for a QPSK signal. This value is expressed as a percentage. This value is obtained by averaging the RMS phase errors obtained over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The phase error of a chip is the difference in the phases of the received chip and the ideal chip. The RMS phase error is obtained from all the chips in the measurement interval.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the mean of the RMS phase error values for a QPSK signal. This value is expressed as a percentage. This value is obtained by averaging the RMS phase errors obtained over all averaging acquisitions. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_mean_rms_evm(selector_string)[source]

Gets the mean of the RMS EVM values for a QPSK signal. This value is expressed as a percentage. This value is obtained by averaging the RMS EVMs over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.

The EVM of a chip is the magnitude of the vector difference between the received chip and the ideal chip. The RMS EVM is obtained from all the chips in the measurement interval.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):: Returns the mean of the RMS EVM values for a QPSK signal. This value is expressed as a percentage. This value is obtained by averaging the RMS EVMs over all averaging iterations. The number of acquisitions is specified by the value of the QEVM_AVERAGING_COUNT attribute.
error_code (int):: Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)