Although another
Path Constructor needs to be adopted to recover the c-to-v messages
when needed, its area requirement is much smaller than
that of a RAM A. In the forward-backward check node processing,
three rounds of computations are carried out: forward,
backward, and merging. Although the backward processing and
merging can be carried out simultaneously, they need to be overlapped
with the forward processing for the next layer in order to
avoid memory access conflicts and increase the speed