Accurate determination of transport block size for 5G new radio

The data payload from the medium access control layer to the physical layer is referred to as the transport block (TB). In fifth-generation new radio, the TB size is determined by using a formula due to large variations of available resource elements (REs) per resource block (RB). To ensure that a matching TB size can easily be scheduled in the retransmission instance, the reference number of REs is used to determine the TB size. As a result, the actual code rate may be much higher than the target code rate. This degrades the performance of the channel coding and increases the likelihood of the decoding failure. To solve these problems, the authors quantise the number of REs within the scheduled duration that are not available for the data transmission and the demodulation reference signal transmission. The difference between the reference number of REs of the traditional scheme and the quantised number is used to determine the TB size in the proposed scheme. Compared to the traditional scheme, the proposed scheme reduces the difference between the actual code rate and the target code rate.