Achievable Error Exponents of One-Way and Two-Way AWGN Channels

Achievable error exponents for the one-way with noisy feedback and two-way AWGN channels are derived transmission of a finite number messages M under almost sure (AS) expected block (EXP) transmit power constraints. In setting feedback, an AS constraint, known linear non-linear passive schemes modified to incorporate constraints in link as well. addition, new active scheme is presented which receiver feeds back most likely pair codewords, transmitter re-transmits these two was originally sent. This outperforms one all channel parameters; others low noise variance. Under EXP achievable exponent generalized any arbitrary but through use simplex codes erasure decoding. setting, each user has its own message send addition (possibly) aiding opposite direction. Two-way regions defined first time both For achievability schemes, or interaction leads gains direction, possibly at expense decrease attained other The relationship between n supported by our strategies explored.