Analysis of Channel-Adaptive Packet Transmission Over Fading Channels With Transmit Buffer Management

In this paper, we study the performance of a channel-adaptive packet transmission system over fading channels with a finite transmit buffer. This transmission scheme combines the essential features of two popular communication techniques, namely adaptive modulation and coding (AMC) and automatic repeat request. Our joint design takes into consideration the size limitation and the dynamic variation of the transmit buffer. Specifically, we introduce a novel buffer-assisted mode selection strategy for AMC in addition to the traditional channel-quality-based strategy. We also developed three buffer management schemes. Moreover, we develop a Markov-chain-based analytical framework to investigate the performance, efficiency, and complexity of this transmission system with different mode selection strategies and buffer management schemes. This general framework allows us to derive the accurate analytical expressions for the packet loss, average delay, spectral/power efficiency, and average feedback load of this system over general fading channel. The selected numerical results, together with the related discussion, illustrate the various design tradeoffs.