optic.comm.metrics.calcLLR

calcLLR(rxSymb, σ2, constSymb, bitMap, px)

LLR calculation (circular AGWN channel).

Parameters:

• rxSymb (np.array) – Received symbol sequence.

• σ2 (scalar) – Noise variance.

• constSymb ((M, 1) np.array) – Constellation symbols.

• px ((M, 1) np.array) – Prior symbol probabilities.

• bitMap ((M, log2(M)) np.array) – Bit-to-symbol mapping.

Returns:

LLRs – sequence of calculated LLRs.

Return type:

np.array

References

[1] A. Alvarado, T. Fehenberger, B. Chen, e F. M. J. Willems, “Achievable Information Rates for Fiber Optics: Applications and Computations”, Journal of Lightwave Technology, vol. 36, nº 2, p. 424–439, jan. 2018, doi: 10.1109/JLT.2017.2786351.