  In this paper, we investigate the impact of coding on the Age of Information
(AoI) in a two-user broadcast symbol erasure channel with feedback. We assume
each update consists of $K$ symbols and the source is able to broadcast one
symbol in each time slot. Due to random channel noise, the intended symbol at
each user will be erased according to an independent and identically
distributed (i.i.d.) Bernoulli process. A user is able to successfully decode
an update if it accumulates sufficient information and successfully decodes the
$K$ symbols of the update. Assuming prefect feedback information at the source
right after the transmission of each symbol, our objective is to design an
adaptive coding scheme to achieve small AoI at both users. We propose a novel
coding scheme to judiciously combine symbols from different updates together,
and analyze the AoI at both users. Compared with a baseline greedy scheme, the
proposed adaptive coding scheme improves the AoI at the weak user by orders of
magnitude without compromising the AoI at the strong user.
