Coding for a Bit-Shift Channel with Applications to Inductively Coupled Channels

In this work, we will consider coding for a bit-shift channel with applications to inductively coupled channels. Inductive coupling is a technique wherein one device (the reader) induces an electrical current in another device (the tag), thereby providing not only power for the tag, but also a communications channel. Most errors in the reader-to-tag channel are due to incorrect timing. In this work, we propose to model the timing errors in the reader-to-tag communications channel by a simple bit-shift channel. We will present optimal single bit-shift error-correcting codes for this simple bit-shift channel that also have large average power. This is important, since the tag gets its entire power from the received signal, and the information should be modulated in a way that maximizes the power transferred to the tag.