Parameters estimation

Module holding estimators for Bob.

Base

Define abstract class for estimators.

qosst_bob.parameters_estimation.base.complex_to_real(input_data: ndarray) → ndarray

Transform the input data of a complex np array of size n to a real np array of size 2n such that if the input data is [a_1+i*b_1, a_2+i*b_2, …, a_n+i*b_n] then the output array is [a_1, b_1, a_2, b_2, …, a_n, b_n].

Parameters:: input_data (np.ndarray) – the input complex array of size n.
Returns:: the output real array of size 2n.
Return type:: np.ndarray

class qosst_bob.parameters_estimation.base.BaseEstimator

Base abstract estimator.

abstract static estimate(alice_symbols: ndarray, bob_symbols: ndarray, alice_photon_number: float, electronic_symbols: ndarray, electronic_shot_symbols: ndarray) → Tuple[float, float, float]

Estimate the transmittance and excess noise given the symbols of Alice and Bob, symbols for the shot noise and electronic noise and the avarage photon number at Alice’s output.

Transmittance should be here understood as total transmittance hence eta * T.

Parameters:

alice_symbols (np.ndarray) – symbols sent by Alice.
bob_symbols (np.ndarray) – symbols received by Bob, after DSP.
alice_photon_number (float) – average number of photon at Alice’s output.
electronic_symbols (np.ndarray) – electronic noise data after equivalent DSP.
electronic_shot_symbols (np.ndarray) – electronic and shot noise data, after equivalent DSP.

Returns:

tuple containing the transmittance, the excess noise at Bob side and the electronic noise.

Return type:

Tuple[float, float, float]

class qosst_bob.parameters_estimation.base.DefaultEstimator

Default estimator.

static estimate(alice_symbols: ndarray, bob_symbols: ndarray, alice_photon_number: float, electronic_symbols: ndarray, electronic_shot_symbols: ndarray) → Tuple[float, float, float]

Estimate the transmittance, excess noise and electronic noise by using the covariance method.

Parameters:

alice_symbols (np.ndarray) – symbols sent by Alice.
bob_symbols (np.ndarray) – symbols received by Bob, after DSP.
alice_photon_number (float) – average number of photon at Alice’s output.
electronic_symbols (np.ndarray) – electronic noise data after equivalent DSP.
electronic_shot_symbols (np.ndarray) – electronic and shot noise data, after equivalent DSP.

Returns:

tuple containing the transmittance, the excess noise at Bob side and the electronic noise.

Return type:

Tuple[float, float, float]