# Convolutional coding that payload length does not change

• Consider the possibility that there is a typo in the figure. They are apparently using a $(3,1)$ systematic convolutional code with generator matrix $[1,1+x+x^2, 1+x^2]$ and so the coded UL-PHY-CONTENT should read "$240$ to $528$" or "$240$ to $536$" bits if the trailing tail of 6 bits (caused by the emptying of the code buffer) is included. – Dilip Sarwate Aug 13 at 19:30