Technology for a transmitter operable to perform data transmissions using low density parity check (LDPC) codes is disclosed. The transmitter can determine soft buffer information (Nsoft) for a receiver. The transmitter can determine a soft buffer partition per HARQ process (NIR) for the UE. The transmitter can obtain, for a transport block, a number of code block segments (C). The transmitter can select a shift size value (z). The transmitter can determine an amount of soft buffer available for the code block segments (Ncb) based on NIR, C, and z. The transmitter can encode the code block segments based on an LDPC coding scheme to obtain encoded parity bits. The transmitter can select a subset of the encoded parity bits based on the determined amount of soft buffer associated with the code block segments.