In one or more embodiments, a data processing apparatus is configured to receive data symbols transmitted from one or more endpoint devices. Each of the data symbols is transmitted in a respective temporal position assigned for communication by one of the plurality of endpoints. The data processing apparatus is configured to recover data from two or more transmission(s)/retransmission(s) (of the same data) that are received in error and have different temporal positions. The corresponding data symbols in error are phase-aligned per a common reference point and energy is accumulated therefrom. The data processing apparatus discerns correct data values from the accumulated energy.