Recently, federated learning (FL) has sparked widespread attention as a promising decentralized machine learning approach which provides privacy and low delay. However, communication bottleneck still constitutes an issue, that needs to be resolved for an efficient deployment of FL over wireless networks. In this paper, we aim to minimize the total convergence time of FL, by quantizing the local model parameters prior to uplink transmission. More specifically, the convergence analysis of the FL algorithm with stochastic quantization is firstly presented, which reveals the impact of the quantization error on the convergence rate. Following that, we jointly optimize the computing, communication resources and number of quantization bits, in order to guarantee minimized convergence time across all global rounds, subject to energy and quantization error requirements, which stem from the convergence analysis. The impact of the quantization error on the convergence time is evaluated and the trade-off among model accuracy and timely execution is revealed. Moreover, the proposed method is shown to result in faster convergence in comparison with baseline schemes. Finally, useful insights for the selection of the quantization error tolerance are provided.

本文旨在通过在上传之前对本地模型参数进行量化，最小化联邦学习的总收敛时间，以保证在所有全局轮次中的最小收敛时间。我们利用随机量化对FL算法的收敛性进行了收敛分析，同时综合优化了计算，通讯资源和量化比特数，以保证在所有全局轮次中的最小收敛时间，同时满足能源和量化误差的要求。我们对量化误差对收敛时间的影响进行了评估，并揭示了模型准确性与及时执行之间的平衡。此外，所提出的方法被证明与基线方案相比，可以加速收敛速度，并为量化误差容忍度的选择提供有用的见解。

无线量化联邦学习：一种联合计算和通信设计