School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, China

Huawei Technologies Duesseldorf GmbH Munich Research Center, Munich, Germany

School of Engineering and Informatics, University of Sussex, Brighton, U.K.

Department of Mathematics and Statistics, University of West Florida, Pensacola, FL, USA

School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Ave, Singapore

Department of Informatics, University of Oslo, Oslo, Norway