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Related papers: Grant-Free Random Access in Massive MIMO for Stati…

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Grant-free random access (RA) has been recognized as a promising solution to support massive connectivity due to the removal of the uplink grant request procedures. While most endeavours assume perfect synchronization among users and the…

Signal Processing · Electrical Eng. & Systems 2024-02-29 Xinyu Bian , Yuyi Mao , Jun Zhang

Radio access management plays a vital role in delay and energy consumption of connected devices. The radio access in existing cellular networks is unable to efficiently support massive connectivity, due to its signaling overhead. In this…

Information Theory · Computer Science 2017-09-08 Amin Azari , Petar Popovski , Guowang Miao , Cedomir Stefanovic

Efficient Random Access (RA) is critical for enabling reliable communication in Industrial Internet of Things (IIoT) networks. Herein, we propose a deep reinforcement learning based distributed RA scheme, entitled Neural Network-Based…

Optimization and Control · Mathematics 2024-11-25 Prasoon Raghuwanshi , Onel Luis Alcaraz López , Neelesh B. Mehta , Hirley Alves , Matti Latva-aho

Massive multiple-input multiple-output (MIMO) systems are cellular networks where the base stations (BSs) are equipped with unconventionally many antennas, deployed on co-located or distributed arrays. Huge spatial degrees-of-freedom are…

Information Theory · Computer Science 2015-04-30 Emil Björnson , Michail Matthaiou , Mérouane Debbah

A Cell-Free Massive MIMO (multiple-input multiple-output) system comprises a very large number of distributed access points (APs)which simultaneously serve a much smaller number of users over the same time/frequency resources based on…

Information Theory · Computer Science 2017-01-18 Hien Quoc Ngo , Alexei Ashikhmin , Hong Yang , Erik G. Larsson , Thomas L. Marzetta

Internet of things, supported by machine-to-machine (M2M) communications, is one of the most important applications for future 6th generation (6G) systems. A major challenge facing by 6G is enabling a massive number of M2M devices to access…

Information Theory · Computer Science 2022-09-30 Kan Zheng , Haojun Yang , Xiong Xiong , Jie Mei , Kuan Zhang

Massive number of internet of things (IoT) devices are expected to simultaneously connect to the mMTC and beyond future generations of wireless network, posing severe challenge to aspects such as RACH procedure, user equipment detection and…

Information Theory · Computer Science 2018-05-21 Zhifeng Yuan , Weimin Li , Yuzhou Hu , Xun Yang , Hong Tang , Jianqiang Dai

Tailor-made for massive connectivity and sporadic access, grant-free random access has become a promising candidate access protocol for massive machine-type communications (mMTC). Compared with conventional grant-based protocols, grant-free…

Signal Processing · Electrical Eng. & Systems 2022-10-26 Zhaoji Zhang , Qinghua Guo , Ying Li , Ming Jin , Chongwen Huang

This article considers the massive MIMO unsourced random access problem on a quasi-static Rayleigh fading channel. Given a fixed message length and a prescribed number of channel uses, the objective is to construct a coding scheme that…

Information Theory · Computer Science 2022-03-09 Michail Gkagkos , Krishna R. Narayanan , Jean-Francois Chamberland , Costas N. Georghiades

A multi-cell Fog-Radio Access Network (F-RAN) architecture is considered in which Internet of Things (IoT) devices periodically make noisy observations of a Quantity of Interest (QoI) and transmit using grant-free access in the uplink. The…

Information Theory · Computer Science 2020-01-22 Rahif Kassab , Osvaldo Simeone , Petar Popovski

Massive machine-type communications (mMTC) in 6G requires supporting a massive number of devices with limited resources, posing challenges in efficient random access. Grant-free random access and uplink non-orthogonal multiple access (NOMA)…

Information Theory · Computer Science 2023-06-01 Thushan Sivalingam , Samad Ali , Nurul Huda Mahmood , Nandana Rajatheva , Matti Latva Aho

Existing works on Cell-Free Massive MIMO primarily focus on optimising system throughput and energy efficiency under high-traffic scenarios with only a limited focus on variable user demand as required by higher network layers.…

Signal Processing · Electrical Eng. & Systems 2025-06-10 Robbert Beerten , Vida Ranjbar , Hazem Sallouha , Sofie Pollin

Wireless surveillance, in which untrusted communications links are proactively monitored by legitimate agencies, has started to garner a lot of interest for enhancing the national security. In this paper, we propose a new cell-free massive…

Information Theory · Computer Science 2023-10-17 Zahra Mobini , Hien Quoc Ngo , Michail Matthaiou , Lajos Hanzo

The emerging Internet of Things (IoT) and bidirectional communications in smart grid are expected to improve smart grid capabilities and electricity management. Because of massive number of IoT devices in smart grid, size of the data to be…

Signal Processing · Electrical Eng. & Systems 2021-08-13 Neji Mensi , Danda B. Rawat , Elyes Balti

Most existing studies on joint activity detection and channel estimation for grant-free massive random access (RA) systems assume perfect synchronization among all active users, which is hard to achieve in practice. Therefore, this paper…

Signal Processing · Electrical Eng. & Systems 2023-05-23 Xinyu Bian , Yuyi Mao , Jun Zhang

We consider transmission of system information in a cell-free massive MIMO system, when the transmitting access points do not have any channel state information and the receiving terminal has to estimate the channel based on downlink…

Information Theory · Computer Science 2019-01-29 Marcus Karlsson , Emil Björnson , Erik G. Larsson

The current random access (RA) allocation techniques suffer from congestion and high signaling overhead while serving massive machine type communication (mMTC) applications. To this end, 3GPP introduced the need to use fast uplink grant…

Networking and Internet Architecture · Computer Science 2021-08-24 Eslam Eldeeb , Mohammad Shehab , Hirley Alves

This letter focuses on integrating rate-splitting multiple-access (RSMA) with time-division-duplex Cell-free Massive MIMO (multiple-input multiple-output) for massive machine-type communications. Due to the large number of devices, their…

Signal Processing · Electrical Eng. & Systems 2022-05-06 Anup Mishra , Yijie Mao , Luca Sanguinetti , Bruno Clerckx

Massive multi-input multi-output (MIMO) has evolved along two tracks: cellular and cell-free, each with unique advantages and limitations. The cellular approach suffers from worse user spectral efficiency at cell edges, whereas the…

Information Theory · Computer Science 2025-06-30 Wei Jiang , Hans D. Schotten

A large-scale distributed antenna system that serves the users by coherent joint transmission is called Cell-free Massive MIMO (multiple input multiple output). For a given user set, only a subset of the access points (APs) is likely needed…

Information Theory · Computer Science 2019-11-27 Trinh Van Chien , Emil Björnson , Erik G. Larsson