Angle of Arrival / Departure#

sl_rtl_aox_array_type#

sl_rtl_aox_array_type

AoX antenna array type.

sl_rtl_aox_switch_pattern_array#

sl_rtl_aox_switch_pattern_array

sl_rtl_aox_switch_pattern_options#

sl_rtl_aox_switch_pattern_options

sl_rtl_aox_mode#

sl_rtl_aox_mode

AoA, AoD (and AoX for backward compatibility) estimator modes.

sl_rtl_aox_constraint_type#

sl_rtl_aox_constraint_type

sl_rtl_aox_switch_pattern_mode#

sl_rtl_aox_switch_pattern_mode

sl_rtl_slib_iq_sample_qa_result_t#

sl_rtl_slib_iq_sample_qa_result_t

sl_rtl_aox_libitem#

typedef void* sl_rtl_aox_libitem

Angle of Arrival / Departure library item.

sl_rtl_aox_antenna_pattern#

typedef void* sl_rtl_aox_antenna_pattern

Angle of Arrival / Departure antenna array radiation pattern.

sl_rtl_aox_init#

enum sl_rtl_error_code sl_rtl_aox_init (sl_rtl_aox_libitem * item)

Initialize the AoX libitem instance.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_deinit#

enum sl_rtl_error_code sl_rtl_aox_deinit (sl_rtl_aox_libitem * item)

Deinitialize a libitem instance of the AoX estimator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_set_num_snapshots#

enum sl_rtl_error_code sl_rtl_aox_set_num_snapshots (sl_rtl_aox_libitem * item, uint32_t num_snapshots)

Set the number of signal snapshots to be used in the angle estimation.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_set_array_type#

enum sl_rtl_error_code sl_rtl_aox_set_array_type (sl_rtl_aox_libitem * item, enum sl_rtl_aox_array_type array_type)

Set the array type used with the estimator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

Set the array type used with the estimator. For example, the array type should be set to SL_RTL_AOX_ARRAY_TYPE_4x4_URA when using the reference 4x4 URA board.

sl_rtl_aox_set_mode#

enum sl_rtl_error_code sl_rtl_aox_set_mode (sl_rtl_aox_libitem * item, enum sl_rtl_aox_mode mode)

Set the estimation mode.

Returns

• SL_RTL_ERROR_SUCCESS if successful

Set the estimation mode. For example, ::SL_RTL_AOX_MODE_BASIC sets medium filtering and estimates both azimuth and elevation. For further description of the modes, see the documentation of sl_rtl_aox_mode.

sl_rtl_aox_calculate_iq_sample_phase_rotation#

enum sl_rtl_error_code sl_rtl_aox_calculate_iq_sample_phase_rotation (sl_rtl_aox_libitem * item, float iq_data_downsampling_factor, float * i_samples, float * q_samples, uint32_t num_samples, float * phase_rotation_out)

Estimate the I/Q-sample phase rotation error in degrees.

Returns

• SL_RTL_ERROR_SUCCESS if successful

Estimate the I/Q-sample phase rotation error caused by switching and CTE frequency error based on I/Q samples from the reference period.

sl_rtl_aox_set_iq_sample_phase_rotation#

enum sl_rtl_error_code sl_rtl_aox_set_iq_sample_phase_rotation (sl_rtl_aox_libitem * item, float phase_rotation)

Set a constant value of I/Q sample phase rotation in degrees.

Returns

• SL_RTL_ERROR_SUCCESS if successful

Set a constant value of I/Q sample phase rotation in degrees. The sample rotation can be used to correct the switching and CTE frequency error. Note

• : This function should be called only after the estimator is created.

sl_rtl_aox_add_constraint#

enum sl_rtl_error_code sl_rtl_aox_add_constraint (sl_rtl_aox_libitem * item, enum sl_rtl_aox_constraint_type constraint_type, float min_value, float max_value)

Add constraints for the estimator. Call before sl_rtl_aox_create_estimator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

For example, constraint for SL_RTL_AOX_CONSTRAINT_TYPE_AZIMUTH with min_value = 0 and max_value = 90 means that the angular range 0 to 90 degrees is excluded from the estimators internal processing range and angle estimated between that range are not considered as valid results. Setting constraints will help ruling out false multipath-detections when the locator is installed nearby a wall or a RF-reflective surface. Note

• : This function must called before the estimator is created.

sl_rtl_aox_set_sample_rate#

enum sl_rtl_error_code sl_rtl_aox_set_sample_rate (sl_rtl_aox_libitem * item, float sampleRate)

Configure the IQ sampling sample rate for the library.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_set_num_radio_channels#

enum sl_rtl_error_code sl_rtl_aox_set_num_radio_channels (sl_rtl_aox_libitem * item, uint32_t channels)

Configure the number of radio channels.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_iq_sample_qa_configure#

enum sl_rtl_error_code sl_rtl_aox_iq_sample_qa_configure (sl_rtl_aox_libitem * item)

Configure the IQ sample quality analysis.

Returns

• SL_RTL_ERROR_SUCCESS if successful

This function turns the IQ sample quality analysis, which is not done by default.

sl_rtl_aox_iq_sample_qa_get_results#

uint32_t sl_rtl_aox_iq_sample_qa_get_results (sl_rtl_aox_libitem * item)

Get the IQ sample quality analysis overall results.

Returns

• bitmask of found problems, zero indicates that everything is OK

sl_rtl_aox_iq_sample_qa_get_details#

enum sl_rtl_error_code sl_rtl_aox_iq_sample_qa_get_details (sl_rtl_aox_libitem * item, sl_rtl_clib_iq_sample_qa_dataset_t * results, sl_rtl_clib_iq_sample_qa_antenna_data_t * antenna_data)

Get the IQ sample quality analysis detailed results for the latest packet.

Returns

• SL_RTL_ERROR_SUCCESS if successful

Fetch the results for the latest packet.

sl_rtl_aox_iq_sample_qa_get_channel_details#

enum sl_rtl_error_code sl_rtl_aox_iq_sample_qa_get_channel_details (sl_rtl_aox_libitem * item, uint8_t channel, sl_rtl_clib_iq_sample_qa_dataset_t * results, sl_rtl_clib_iq_sample_qa_antenna_data_t * antenna_data)

Get the IQ sample quality analysis detailed results for the requested radio channel.

Returns

• SL_RTL_ERROR_SUCCESS if successful

Fetch the latest results for the given radio channel, which may be other than the latest packet received.

sl_rtl_aox_create_estimator#

enum sl_rtl_error_code sl_rtl_aox_create_estimator (sl_rtl_aox_libitem * item)

Create the estimator after initializing the libitem and setting parameters.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_convert_raw_samples#

enum sl_rtl_error_code sl_rtl_aox_convert_raw_samples (sl_rtl_aox_libitem * item, uint32_t start_offset, float iq_data_downsampling_factor, float * raw_i_samples_in, float * raw_q_samples_in, uint32_t num_raw_samples_in, float ** i_samples_out, float ** q_samples_out, uint32_t num_snapshots_out)

Convert data in RAW IQ-data buffers to downsampled IQ-data buffers.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_calculate_number_of_snapshots#

enum sl_rtl_error_code sl_rtl_aox_calculate_number_of_snapshots (sl_rtl_aox_libitem * item, uint32_t num_raw_samples_in, uint32_t start_offset, float iq_data_downsampling_factor, uint32_t num_channels, uint32_t * num_snapshots_out)

Calculate the number of downsampled snapshots in a RAW IQ-data buffer. Use this function to get the number of snapshots to allocate the i_samples and q_samples buffers for the process-function.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_set_switch_pattern_mode#

enum sl_rtl_error_code sl_rtl_aox_set_switch_pattern_mode (sl_rtl_aox_libitem * item, enum sl_rtl_aox_switch_pattern_mode mode)

Set switch pattern mode. Sets internal mode used by the library. See enum sl_rtl_aox_switch_pattern_mode for detailed description of the modes. If this function isn't called, a default switch pattern of: 0, 1, 2, 3, ..., N-1 will be used, where N is the number of antennas. Call this function at run-time after initializing and creating the estimator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_update_switch_pattern#

enum sl_rtl_error_code sl_rtl_aox_update_switch_pattern (sl_rtl_aox_libitem * item, uint32_t * switch_pattern_in, uint32_t ** switch_pattern_out)

Update switch pattern, which is used by the estimator algorithm. This function must be called before calling the function sl_rtl_aox_process. Call this function at run-time after initializing and creating the estimator.

When using a custom pattern in SL_RTL_AOX_SWITCH_PATTERN_MODE_EXTERNAL mode, the pattern in switch_pattern_in must not contain duplicate elements and the antenna indices must be within the range 0 to (number_of_antennas - 1). Number_of_antennas is the amount of antennas in the set array type, for example for the 4x4 URA this is 16 and for the 1x4 ULA this is 4. The length of the switching pattern must be equal to number_of_antennas.

Note: The RF switch pattern indices may be different to the indices required by the RTL algorithm. For example, a 1x4 ULA might use RF controls [12, 13, 14, 15] for switching the antennas 1-4, but the RTL algorithm requires the switch pattern [0, 1, 2, 3]. If the RF controls are switched as [14, 15, 13, 12], the RTL algorithm requires the pattern [2, 3, 1, 0].

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_set_switch_pattern_seed#

enum sl_rtl_error_code sl_rtl_aox_set_switch_pattern_seed (sl_rtl_aox_libitem * item, int32_t seed_value)

Set the random seed for the switch pattern, which is used for the random pattern mode. Call this function at run-time after initializing and creating the estimator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_convert_switch_pattern#

enum sl_rtl_error_code sl_rtl_aox_convert_switch_pattern (sl_rtl_aox_libitem * item, uint32_t array_id, uint32_t options, uint32_t switch_pattern_size_in, uint32_t * switch_pattern_in, uint32_t * switch_pattern_size_out, uint32_t ** switch_pattern_out)

Convert switching pattern from antenna indices to antenna switching pin control logic. Call this function at run-time after initializing and creating the estimator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_reset_estimator#

enum sl_rtl_error_code sl_rtl_aox_reset_estimator (sl_rtl_aox_libitem * item)

Reset estimator state. Calling this function causes the selected aox-mode to start from its initial state. Call this function at run-time after initializing and creating the estimator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_process#

enum sl_rtl_error_code sl_rtl_aox_process (sl_rtl_aox_libitem * item, float ** i_samples, float ** q_samples, float tone_frequency, float * az_out, float * el_out)

Calculate the angle estimate.

Returns

• SL_RTL_ERROR_SUCCESS if successful and SL_RTL_ERROR_ESTIMATION_IN_PROGRESS if estimate is not yet final and more I/Q data needs to be processed.

Calculate the angle estimate from the given I/Q samples captured at the given frequency. Call this function with new I/Q data as many times as indicated by the sl_rtl_aox_mode used by the estimator before the final estimate is output.

sl_rtl_aox_get_latest_aox_standard_deviation#

enum sl_rtl_error_code sl_rtl_aox_get_latest_aox_standard_deviation (sl_rtl_aox_libitem * item, float * az_std_dev, float * el_std_dev)

Get the standard deviation for the latest AoA/AoD-estimate.

Returns

• SL_RTL_ERROR_SUCCESS if successful

Call this function after sl_rtl_aox_process to fetch standard deviation for the latest AoA/AoD-estimate. Positive standard deviations indicate line-of-sight detection and negative values indicate likely non-line-of-sight detection.

sl_rtl_aox_get_latest_aoa_standard_deviation#

static enum sl_rtl_error_code sl_rtl_aox_get_latest_aoa_standard_deviation (sl_rtl_aox_libitem * item, float * az_std_dev, float * el_std_dev)

Kept for backward compatibility

sl_rtl_aox_get_latest_aod_standard_deviation#

static enum sl_rtl_error_code sl_rtl_aox_get_latest_aod_standard_deviation (sl_rtl_aox_libitem * item, float * az_std_dev, float * el_std_dev)

Kept for backward compatibility

sl_rtl_aox_set_expected_direction#

enum sl_rtl_error_code sl_rtl_aox_set_expected_direction (sl_rtl_aox_libitem * item, float expected_az, float expected_el)

Feed the expected angles back to the locator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

The position algorithm has a more complete view of the asset's location. The direction it should be found can be calculated back and fed to the locator, so that it can recover faster when, for example, it has locked to a reflection rather than to the line of sight signal. See also sl_rtl_loc_get_expected_direction().

sl_rtl_aox_set_expected_deviation#

enum sl_rtl_error_code sl_rtl_aox_set_expected_deviation (sl_rtl_aox_libitem * item, float deviation_az, float deviation_el)

Feed the expected angle deviations back to the locator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

Report expected deviations calculated by the position algorithm back to the locator so that angles are calculated more accurately taking in account the correctness of the expected directions. If sl_rtl_aox_set_expected_direction() is called but this function is not called, the algorithm will use default values for the expected deviations. See also sl_rtl_loc_get_expected_deviation() and sl_rtl_aox_set_expected_direction().

sl_rtl_aox_clear_expected_direction#

enum sl_rtl_error_code sl_rtl_aox_clear_expected_direction (sl_rtl_aox_libitem * item)

Clear the expected directions and deviations from the locator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

See also sl_rtl_aox_set_expected_direction() and sl_rtl_aox_set_expected_deviation().

sl_rtl_aox_enable_spectrum#

enum sl_rtl_error_code sl_rtl_aox_enable_spectrum (sl_rtl_aox_libitem * item, bool enable)

Enable or disable outputting the pseudospectrum. This function should be called before creating the estimator.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_get_spectrum_size#

enum sl_rtl_error_code sl_rtl_aox_get_spectrum_size (sl_rtl_aox_libitem * item, uint32_t * rows, uint32_t * cols)

Get the size of the pseudospectrum. This function should be called after calling the AoX process function.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_get_polarization_spectrum_size#

enum sl_rtl_error_code sl_rtl_aox_get_polarization_spectrum_size (sl_rtl_aox_libitem * item, uint32_t * rows, uint32_t * cols)

Get the size of the polarization pseudospectrum. This function should be called after calling the AoX process function.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_get_spectrum#

enum sl_rtl_error_code sl_rtl_aox_get_spectrum (sl_rtl_aox_libitem * item, float ** spectrum_out)

Get the pseudospectrum. Memory for the output spectrum must be allocated by the user, the size of the rows and columns are given by sl_rtl_aox_get_spectrum_size().

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_get_polarization_spectrum#

enum sl_rtl_error_code sl_rtl_aox_get_polarization_spectrum (sl_rtl_aox_libitem * item, float ** spectrum_out)

Get the polarization spectrum. Memory for the output spectrum must be allocated by the user, the size of the rows and columns are given by sl_rtl_aox_get_polarization_spectrum_size().

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_antenna_pattern_init#

enum sl_rtl_error_code sl_rtl_aox_antenna_pattern_init (sl_rtl_aox_antenna_pattern * pattern, enum sl_rtl_aox_array_type array_type)

Initialize the antenna radiation pattern item for the given array board. The antenna pattern item can be shared by multiple different estimators.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_set_antenna_pattern#

enum sl_rtl_error_code sl_rtl_aox_set_antenna_pattern (sl_rtl_aox_libitem * item, sl_rtl_aox_antenna_pattern * pattern)

Set the given estimator to use the given antenna radiation pattern in the model. The same antenna pattern can be shared between multiple estimators. The antenna pattern can be cleared for an estimator by setting it to NULL. The estimator will then use the default model. Note

• : This function should be called only after the estimator is created.

Returns

• SL_RTL_ERROR_SUCCESS if successful

sl_rtl_aox_antenna_pattern_deinit#

enum sl_rtl_error_code sl_rtl_aox_antenna_pattern_deinit (sl_rtl_aox_antenna_pattern * pattern)

Deinitialize the antenna radiation pattern item.

Returns

• SL_RTL_ERROR_SUCCESS if successful

SL_RTL_AOX_IQ_SAMPLE_QA_ALL_OK#

#define SL_RTL_AOX_IQ_SAMPLE_QA_ALL_OK

0

SL_RTL_AOX_IQ_SAMPLE_QA_FAILURE#

#define SL_RTL_AOX_IQ_SAMPLE_QA_FAILURE

0xffffffff

SL_RTL_AOX_IQ_SAMPLE_QA_CLEAR_BIT#

#define SL_RTL_AOX_IQ_SAMPLE_QA_CLEAR_BIT

(code, bit)

SL_RTL_AOX_IQ_SAMPLE_QA_SET_BIT#

#define SL_RTL_AOX_IQ_SAMPLE_QA_SET_BIT

(code, bit)

SL_RTL_AOX_IQ_SAMPLE_QA_IS_SET#

#define SL_RTL_AOX_IQ_SAMPLE_QA_IS_SET

(code, bit)