Rate adaptation via link-layer feedback for goodput maximization over a time-varying channel

Abstract—We consider adapting the transmission rate to maximize the goodput, i.e., the amount of data transmitted without error, over a continuous Markov flat-fading wireless channel. In particular, we consider schemes in which transmitter channel state is inferred from degraded causal error-rate feedback, such as packet-level ACK/NAKs in an automatic repeat request (ARQ) system. In such schemes, the choice of transmission rate affects not only the subsequent goodput but also the subsequent feedback, implying that the optimal rate schedule is given by a partially observable Markov decision process (POMDP). Because solution of the POMDP is computationally impractical, we consider simple suboptimal greedy rate assignment and show that the optimal scheme would itself be greedy if the errorrate feedback was non-degraded. Furthermore, we show that greedy rate assignment using non-degraded feedback yields a total goodput that upper bounds that of optimal rate assignment using degraded fee...

• Type: Conference
• Year: 2008
• Where: CISS
• Authors: Rohit Aggarwal, Phil Schniter, Can Emre Koksal
• Keywords: CISS 2008, Greedy Rate Assignment, Information Management, Optimal Rate, Transmission Rate