Queue length aware power control for delay‐ constrained communication over fading channels

Abstract

In this paper, we study efficient power control schemes for delay sensitive communication over fading channels. Our objective is to find a power control law that optimizes the link layer performance, specifically, minimizes the packet drop probability, subject to a long-term average power constraint.We assume the buffer at the transmitter is finite; hence packet drop happens when the buffer is full.The fading channel under our study has a continuous state, e.g., Rayleigh fading. Since the channel state space is continuous, dynamic programming is not applicable for power control. In this paper, we propose a sub-optimal power control law based on a parametric approach. The proposed power control scheme tries to minimize the packet drop probability by considering the queue length, i.e., reducing the probability of those queue-length states that will cause full buffer. Simulation results show that our proposed power control scheme reduces the packet drop probability by one or two orders of magnitude, compared to the time domain water filling and the truncated channel inversion power control.

Capacity–Delay–Error Boundaries: A Composable Model of Sources and Systems

“…A Poisson process with mean rate λ has probability mass function p N (n, t) = e −λt (λt) n /n!. By insertion into (20) we derive…”

“…A related concept, the delay-limited capacity [18], compensates fluctuations of the fading process using power control to achieve a constant transmission rate. Subsequent works implement power control subject to additional buffering constraints [19], [20]. Recently, the impact of finite blocklength codes on the variability of the capacity is investigated in [21]- [23].…”

Delay-Sensitive Communication Over Fading Channels: Queueing Behavior and Code Parameter Selection

“…We emphasize that the block fading models adopted in many existing studies [2], [3], [4], [13], [16] do not consider the per-symbol correlation and do not allow for a consistent comparison of the performance associated with different block lengths. In block-fading models, varying the block length also implicitly changes the fading process.…”

“…While a number of recent contributions address the tradeoffs between average power, throughput and delay [1], [2], [3], [4], [5], [6], many of these articles make idealized assumptions about the performance of coded transmissions. These assumptions may be reasonable for long codewords, but they are hard to justify for low-latency communication over channels with memory.…”

“…For instance, advanced power-control policies can be tailored to the needs of various applications [12], [13], [1], [3], [14], [6], [15]. Still, such policies usually disregard coding issues by considering a power threshold for reliable transmission.…”