核心概念
The core message of this paper is to propose an approach to minimize the maximum end-to-end latency in an uplink joint source-channel coding (JSCC) system by jointly optimizing the compression ratio, channel truncation threshold, and resource allocation.
摘要
The paper presents a system model for an uplink JSCC-based communication system, where each device compresses its source data using a JSCC encoder and transmits the encoded symbols to a base station. The base station then decodes the received symbols using a JSCC decoder.
The authors first analyze the relationship between end-to-end latency and task performance, and establish an end-to-end delay model for each device. They then formulate an optimization problem to minimize the maximum end-to-end latency across all devices while ensuring the task performance requirement for each device is met.
The optimization problem is shown to be NP-hard, so the authors transform it into a more tractable form. They derive the closed-form solution for the optimal compression ratio, channel truncation threshold selection, and resource allocation policy. Additionally, a heuristic algorithm with low complexity is proposed to solve the problem.
Simulation results demonstrate that both the proposed optimal algorithm and the heuristic algorithm significantly reduce the end-to-end latency compared to benchmark schemes. The heuristic algorithm achieves nearly the same performance as the optimal solution but with considerably lower computational complexity.
統計資料
The computational cost of the encoder at the local device k is LkCl
k = LkCsHW, where Lk is the number of images to be processed at device k, Cs is the required number of CPU cycles per pixel using the encoder, and HW is the size of the input image.
The transmission delay of device k is given by tt
k = D0ok
Me−gk
Ts
τk, where D0 is the size of the input image, ok is the compression ratio, gk is the channel truncation threshold, τk is the time slot allocated to device k, and Ts is the symbol duration.
The computational latency of decoding the message from device k at the edge is tc
k = LkCd
k
f c
k
, where Cd
k is the computational cost to decode an image at the decoder of device k, and f c
k is the computation resource allocated to decode the message from device k.
引述
"While existing studies have highlighted the advantages of deep learning (DL)-based joint source-channel coding (JSCC) schemes in enhancing transmission efficiency, they often overlook the crucial aspect of resource management during the deployment phase."
"Motivated by these considerations, this paper aims to minimize the maximum end-to-end latency of the uplink transmission from all devices in the system while ensuring task performance."