User identification for convolutionally/turbo-coded systems and its applications

Motivated by the observation that in some applications, it is highly desirable for the physical layer itself to have a user-identification feature instead of obtaining user identity from the media access control layer, we propose a method to give a convolutionally or turbo-coded system an identity. The user-identification algorithm embeds a periodic identification sequence into the convolutionally coded data sequence in the transmitter, and detects and removes the identification sequence with the assistance from the forward error-correction decoder in the receiver. It does not consume extra transmission bandwidth by tailoring the identification sequences to the codes.