In this letter, we propose a joint active device detection and channel estimation framework based on factor graphs for asynchronous uplink grant-free massive multiple-antenna systems. We then develop the message-scheduling GAMP (MSGAMP) algorithm to perform joint active device detection and channel estimation. In MSGAMP we apply scheduling techniques based on the residual belief propagation (RBP) and the activity user detection (AUD) in which messages are generated using the latest available information. MSGAMP-type schemes show a good performance in terms of activity error rate and normalized mean squared error, requiring a smaller number of iterations for convergence and lower complexity than state-of-the-art techniques.

翻译：在这封信中,我们提出一个联合主动装置探测和频道估计框架,其依据是非同步上行链接无大规模多保险系统系数图,然后我们开发信息排期GAMP(MSGAMP)算法,以进行联合主动装置探测和频道估计。在MSGAMP中,我们应用基于剩余信仰传播(RBP)和活动用户探测(AUD)的列表技术,其中利用现有最新信息生成信息。 MSGAMMP类型计划在活动误差率和普通平均正方差方面表现良好,需要较少的迭代,以达到趋同和复杂性,而不是最先进的技术。