Orthogonal Frequency-Division Multiplexing (OFDM)

This module provides layers and functions to support simulation of OFDM-based systems. The key component is the ResourceGrid that defines how data and pilot symbols are mapped onto a sequence of OFDM symbols with a given FFT size. The resource grid can also define guard and DC carriers which are nulled. In 4G/5G parlance, a ResourceGrid would be a slot.

Once a ResourceGrid is defined, one can use the ResourceGridMapper to map a tensor of complex-valued data symbols onto the resource grid, prior to OFDM modulation using the OFDMModulator or further processing in the frequency domain.

The PilotPattern allows for a fine-grained configuration of how transmitters send pilots for each of their streams or antennas. As the management of pilots in multi-cell MIMO setups can quickly become complicated, the module provides the KroneckerPilotPattern class that automatically generates orthogonal pilot transmissions for all transmitters and streams.

Additionally, the module contains blocks for channel estimation, precoding, equalization, and detection, such as the LSChannelEstimator, the RZFPrecoder, and the LMMSEEqualizer and LinearDetector. These are good starting points for the development of more advanced algorithms and provide robust baselines for benchmarking.