4 research outputs found
Optimal Multiplexed Erasure Codes for Streaming Messages with Different Decoding Delays
This paper considers multiplexing two sequences of messages with two
different decoding delays over a packet erasure channel. In each time slot, the
source constructs a packet based on the current and previous messages and
transmits the packet, which may be erased when the packet travels from the
source to the destination. The destination must perfectly recover every source
message in the first sequence subject to a decoding delay and
every source message in the second sequence subject to a shorter decoding delay
. We assume that the channel loss model
introduces a burst erasure of a fixed length on the discrete timeline.
Under this channel loss assumption, the capacity region for the case where
was previously solved. In this paper, we fully
characterize the capacity region for the remaining case . The key step in the achievability proof is achieving the
non-trivial corner point of the capacity region through using a multiplexed
streaming code constructed by superimposing two single-stream codes. The main
idea in the converse proof is obtaining a genie-aided bound when the channel is
subject to a periodic erasure pattern where each period consists of a
length- burst erasure followed by a length- noiseless
duration.Comment: 20 pages, 1 figure, 1 table, presented in part at 2019 IEEE ISI