Performance Module

The performance module provides performance analysis tools for different modulation and coding schemes.

class spacelink.phy.performance.ErrorMetric(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)[source]

Bases: str, Enum

BER = 'bit error rate'

WER = 'codeword error rate'

FER = 'frame error rate'

PER = 'packet error rate'

class spacelink.phy.performance.ModePerformanceCurve(*, modes: list[LinkMode], metric: ErrorMetric, points: list[tuple[float, float]], ref: str = '')[source]

Bases: BaseModel

Performance characteristics for specific link modes with interpolatable curves.

This class provides methods to convert between Eb/N0 and error rates for given modulation and coding schemes.

Parameters:

modes (list[LinkMode]) – The link mode configurations.
decoder_profile (DecoderProfile) – Configuration for the decoder stages.
metric (ErrorMetric) – Type of error metric (bit error rate, codeword error rate, etc.).
points (list[ErrorCurvePoint]) – List of error rate curve data points for interpolation.
ref (str, optional) – Reference or source of the performance data (default: “”).

modes: list[LinkMode]

metric: ErrorMetric

points: list[tuple[float, float]]

ref: str

classmethod validate_minimum_points(v)[source]

classmethod validate_points_sorted(v)[source]

classmethod validate_error_values_decreasing(v)[source]

__init__(**data)[source]

Create a new model by parsing and validating input data from keyword arguments.

Raises [ValidationError][pydantic_core.ValidationError] if the input data cannot be validated to form a valid model.

self is explicitly positional-only to allow self as a field name.

ebn0_to_error_rate(ebn0)[source]

Find the error rate corresponding to the given Eb/N0.

Parameters:: ebn0 (Decibels) – Energy per bit to noise power spectral density ratio \(E_b/N_0\).
Returns:: Error rate or NaN if the Eb/N0 is outside the range of available performance data. Same shape as ebn0.
Return type:: Dimensionless

error_rate_to_ebn0(error_rate)[source]

Find Eb/N0 required to achieve the target error rate.

Parameters:: error_rate (Dimensionless) – Target error rate.
Returns:: Required Eb/N0 in decibels to achieve the target error rate or NaN if the error rate is outside the range of available performance data. Same shape as error_rate.
Return type:: Decibels

coding_gain(uncoded, error_rate)[source]

Calculate the coding gain relative to an uncoded reference.

The coding gain is the difference in required Eb/N0 between the uncoded and coded systems at the same error rate.

Parameters:

uncoded (ModePerformance) – Performance model for the uncoded reference system. Must use the same error metric as this object.
error_rate (Dimensionless) – Error rate at which to evaluate the coding gain.

Returns:

Coding gain in decibels or NaN if the error rate is outside the range of the available performance data. Same shape as error_rate.

Return type:

Decibels

Raises:

ValueError – If the uncoded model has a different error metric.

model_config: ClassVar[ConfigDict] = {}: Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].

class spacelink.phy.performance.ModePerformanceThreshold(**data)[source]

Bases: BaseModel

Operating point threshold performance for specific link modes.

This class represents performance data with a single operating point threshold, typically used for standards like DVB-S2 where only quasi-error-free (QEF) operating points are published.

Parameters:

modes (list[LinkMode]) – The link mode configurations.
metric (ErrorMetric) – Type of error metric (bit error rate, codeword error rate, etc.).
ebn0 (float) – Eb/N0 threshold in dB for quasi-error-free operation.
error_rate (float) – Error rate at the threshold point (dimensionless).
ref (str, optional) – Reference or source of the performance data (default: “”).

modes: list[LinkMode]

metric: ErrorMetric

ebn0_val: float

error_rate_val: float

ref: str

property ebn0: Annotated[Quantity, Unit('dB(1)')]

Get the Eb/N0 threshold with proper units.

Returns:: Eb/N0 threshold value.
Return type:: Decibels

property error_rate: Annotated[Quantity, Unit(dimensionless)]

Get the error rate threshold with proper units.

Returns:: Error rate threshold value.
Return type:: Dimensionless

check(ebn0)[source]

Check if the given Eb/N0 meets or exceeds the quasi-error-free threshold.

Parameters:: ebn0 (Decibels) – Energy per bit to noise power spectral density ratio \(E_b/N_0\).
Returns:: True where Eb/N0 meets or exceeds the threshold. Scalar if input is scalar, array if input is array.
Return type:: bool or np.ndarray

margin(ebn0)[source]

Calculate the margin (positive) or shortfall (negative) relative to threshold.

Parameters:: ebn0 (Decibels) – Energy per bit to noise power spectral density ratio \(E_b/N_0\).
Returns:: Margin in dB. Positive values indicate the link exceeds the threshold, negative values indicate it falls short. Same shape as ebn0.
Return type:: Decibels

coding_gain(uncoded)[source]

Calculate the coding gain relative to an uncoded threshold.

The coding gain is the difference in required Eb/N0 between the uncoded and coded systems at the threshold error rate.

Parameters:: uncoded (ModePerformanceThreshold) – Threshold specification for the uncoded reference system. Must use the same error metric and have the same error rate threshold as this object.
Returns:: Coding gain in decibels.
Return type:: Decibels
Raises:: ValueError – If the uncoded threshold has a different error metric or error rate.

model_config: ClassVar[ConfigDict] = {}: Configuration for the model, should be a dictionary conforming to [ConfigDict][pydantic.config.ConfigDict].

spacelink.phy.performance.ModePerformance: alias of ModePerformanceCurve