wideband_sir_db#

sionna.sys.wideband_sir_db(coupling_loss, serving: torch.Tensor | None = None, precision: Literal['single', 'double'] | None = None, device: str | None = None) → torch.Tensor[source]#

Computes wideband SIR from coupling losses.

For a serving BS \(b^\star(u)\) selected by minimum coupling loss,

\[b^\star(u) = \arg\min_b \mathrm{CL}_{b,u},\]

the wideband SIR is

\[\mathrm{SIR}^{\mathrm{WB}}_u = \frac{10^{-\mathrm{CL}_{b^\star,u}/10}} {\sum_{b\ne b^\star}10^{-\mathrm{CL}_{b,u}/10}}.\]

The returned value is \(10\log_{10}(\mathrm{SIR}^{\mathrm{WB}}_u)\). Equal BS transmit powers are assumed and therefore cancel.

With equal BS transmit powers and no small-scale fading, this expression is numerically identical to geometry_sir_db(). The separate name is kept because 3GPP TR 38.901 Phase 2 calibration in Section 7.8 of [TR38901V160100] refers to the corresponding quantity as wideband SIR. It verifies the large-scale interference geometry used before evaluating the Phase 2 small-scale fading metrics.

Parameters:

  • coupling_loss – Coupling loss [dB] with shape [..., num_bs].

  • serving (torch.Tensor | None) – Serving BS indices with shape [...]. If None, the serving BS is selected by serving_indices().

  • precision (Literal['single', 'double'] | None) – Precision used for internal calculations and outputs. If set to None, precision is used.

  • device (str | None) – Device for computation. If None, device is used.

Outputs:

sir – Wideband SIR [dB] with shape [...].