Announcing Sionna v0.16

[faycalaa]

Ray tracing

• Splits path tracing and EM field computation through the addition of two methods to Scene: trace_paths() to trace the paths and compute_fields() to compute the corresponding EM fields
• Scene.compute_fields() can now be executed in graph mode
• Adds a feature to use a callable object to compute radio material properties from the intersection points between rays and the scene and the identifiers of the intersected objects
• Adds a feature to use a callable object to compute the scattering patterns
• Adds a feature to define custom colors for radio devices that are used for rendering and preview
• Enables the instantiation of radio materials without loading a scene (PR Forcing a scene to be loaded prior to defining radio materials has a bit of a code smell #216, contribution by @fklement)
• Fixes a bug with diffraction that was creating NaNs in some scenarios (coverage_map occasionally outputs coverage maps with np.nan values in some pixels #201)
• Fixes a bug that occurred when reversing link directions using Paths.reverse_direction
• (Breaking change) Delay normalization is now done across all receive and transmit antennas of each transmitter-receiver pair
• RadioMaterial properties are not defined anymore as tf.Variable but can now be set freely by the user to be either a tf.Variable or a tf.Tensor
• (Breaking change) Removes the flags trainable_relative_permittivity, trainable_conductivity, trainable_scattering_coefficient, and trainable_xpd_coefficient from RadioMaterial
• Transmitter and Receiver position and orientation are not defined anymore as tf.Variable but can be set freely by the user to be either a tf.Variable or a tf.Tensor
• (Breaking change) Removes the flags trainable_position and trainable_orientation from Transmitter and Receiver
• Fixes a bug with paths that were wrongly flagged as LoS in some multi-link scenarios
• Adds a flag to Scene.compute_paths() and Scene.compute_fields() to disable the addition of random phases to scattered paths
• Fixes the link to the simple_reflector Blender file in API documentation
• Speeds-up Scene.preview() by switching to uint8-typed textures for coverage maps
• Better document the difference between edges and wedges (PR chore(docs): document wedge and edge difference #214, contribution by @jeertmans)
• Fixes Is it possible to run sionna rt with multiple GPUs？ #231
• Fixes Issue with apply_doppler ?  #222
• Fixes RadioMaterial has no attribute trainable (occurs when a material is defined after loading from scene xml) #217
• Fixes Ray tracing: error in scene.compute_paths(), if scattering is activated and more than one receiver in the scene #273

FEC

• Fixes a bug in make_systematic() (PR fixed tracking of column swaps and also adjusted column swaps when ma… #236, contribution by @daniel-x)
• Fixes XLA issue in CN update of LDPCBPDecoder (InvalidArgumentError: Exception encountered when calling layer 'model' (type Model). #255)

MISC

• Adds multi-gpu support via tf.distribute to sim_ber()
• Adds target_ber, target_bler and callback to sim_ber() (PR Add min_bler and callback to sim_ber #257, contribution by @nbecker)
• Update requirements: TensorFlow 2.10 – 2.13, Python 3.9 – 3.11 and Ubuntu 22.04 recommended