Results 261 to 270 of about 4,905,659 (296)
Some of the next articles are maybe not open access.
On the performance of massive grant-free NOMA
2017 IEEE 28th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2017Many uplink grant-free non-orthogonal multiple access (NOMA) schemes have been recently proposed to solve the massive access problem of M2M communications. However, little has been done on characterizing the performance bounds for such systems. In this paper, we take a step forward in this direction.
Rana Abbas +3 more
openaire +1 more source
Flexible Multiplexing of Grant-Free URLLC and eMBB in Uplink
2020 IEEE 31st Annual International Symposium on Personal, Indoor and Mobile Radio Communications, 2020The fifth-generation wireless systems shall serve the traffic of various applications that impose different Quality of Service (QoS) requirements. A significant problem is how to efficiently multiplex flows with different QoS requirements having a limited amount of channel resources.
Ilya Gerasin +2 more
openaire +1 more source
An SCMA-Based Grant-Free Access Scheme
2024 IEEE Wireless Communications and Networking Conference (WCNC)This paper elaborates on the idea of building grant-free channel access schemes from non-orthogonal multiple access ones, and proposes an explicit such scheme based on sparse code multiple access (SCMA). In the designed protocol, SCMA codebooks and pilots are chosen by users in a fully uncoordinated fashion, with multiple pilots associated with the ...
Mirri, Alessandro +4 more
openaire +1 more source
Grant-Free Multiple Access Scheme
2018In this chapter, the grant-free multiple access scheme is introduced for a transmission without dynamic scheduling. A few key technical components have been addressed, including the grant-free resource configuration, user equipment activity identification with contention transmission, HARQ procedure and soft-combining, contention resolutions. Numerical
Liqing Zhang, Jianglei Ma
openaire +1 more source
A Novel Analytical Framework for Massive Grant-Free NOMA
IEEE Transactions on Communications, 2019In this paper, we consider a massive grant-free non-orthogonal multiple access (GF-NOMA) scheme, where devices have strict latency requirements and no retransmission opportunities are available. Each device chooses a pilot sequence from a predetermined set as its signature and transmits its selected pilot and data simultaneously.
Rana Abbas +3 more
openaire +1 more source
Grant-free transmissions based on successive interference cancellation in IoT
2023 35th International Teletraffic Congress (ITC-35), 2023Advancements in the physical layer design are pushing towards a major re-design of multiple access schemes for Next Generation Wireless Communication Systems. Hence, we turn towards random multiple access. We use a general model to investigate the interplay between random multiple access protocols and physical layer functions, specifically Successive ...
Abdul Razzaque, Asmad Bin +1 more
openaire +2 more sources
Diversity-Oriented Grant-Free Transmissions for Underwater Wireless Networks
2021 IEEE/CIC International Conference on Communications in China (ICCC Workshops), 2021Grant-free (GF) transmission has received significant interests in the fifth generation (5G), that distributed transmission shows the potential of reducing the latency and overhead. In this paper, we introduce GF transmission into underwater wireless networks, and propose a diversity-oriented transmission scheme over doubly-selective underwater ...
Lei Yan 0010, Xiaoli Ma, Xinbin Li
openaire +1 more source
On receiver diversity for grant-free based machine type communications
Ad Hoc Networks, 2020Abstract Grant-free access schemes are steadily gaining momentum for emerging machine type communications and internet of things applications. Relying on variations of the classical ALOHA protocol to allow a vast population of users share a common channel in an uncoordinated fashion, these solutions have recently been embedded in international ...
Formaggio, Francesco +2 more
openaire +3 more sources
Efficient User Grouping for Grant-Free URLLC
2023 IEEE International Black Sea Conference on Communications and Networking (BlackSeaCom), 2023Artem N. Krasilov +3 more
openaire +1 more source
Activity Detection in Grant-Free Systems
This thesis investigates various methods that aim to solve the activity detection problem in grant free wireless access. First, a grant-free wireless system model is established considering Gaussian and iterative collision-based packing (ICBP) codebooks.openaire +1 more source