Signal demapping

An apparatus comprising:

• trainable logic configured to quantize a plurality of receiver configurations said trainable logic including,
• determination logic configured to determine a plurality of available receiver configurations and associate each receiver configuration with a context matrix;
• codebook logic configured to select a quantisation codebook to be used by the trainable logic for the context matrices;
• learning logic configured to learn from a training dataset comprising a plurality of received signal samples relevant to reconstruction of a transmitted message;
• said learning logic being configured to,
• generate, from the training dataset, a set of superposed parameters and context matrices corresponding to the plurality of available receiver configurations and a set of contextual parameters for each context, the contextual parameters being generatable from the superposed parameters by combination with the context matrix associated with each receiver configuration;
• quantize the context matrices according to the quantisation codebook;
• and
• repeat the generation of superposed parameters, context matrices and quantization of context matrices until a stop criterion is met.