Filters








5,719 Hits in 7.0 sec

Random Access Protocols for Massive MIMO [article]

Elisabeth de Carvalho, Emil Björnson, Jesper H. Sørensen, Petar Popovski, Erik G. Larsson
2017 arXiv   pre-print
This article motivates the need for random access by the devices to pilot sequences used for channel estimation, and shows that Massive MIMO is a main enabler to achieve fast access with high data rates  ...  , and delay-tolerant access with different data rate levels.  ...  The coded pilot sequence has two parts: (1) non-zero symbols used for channel estimation (useful part) and (2) l null symbols used for collision detection and are placed at random positions in the sequence  ... 
arXiv:1606.02080v2 fatcat:kfnr3rdyxbcefkhwljktpeum3y

Performance Analysis of Network Diversity Multiple Access with Sequential Terminal Detection and Non-Orthogonal Training Sequences

Ramiro Samano-Robles
2018 2018 IEEE 87th Vehicular Technology Conference (VTC Spring)  
This paper presents a new approach for terminal presence detection in the family of training-based algorithms for random access called network diversity multiple access (NDMA).  ...  The analysis here presented includes the effects of multiple access interference caused by non orthogonal training sequences and the effect of sequential collision multiplicity estimation.  ...  ACKNOWLEDGMENTS This work was partially supported by National Funds through FCT (Portuguese Foundation for Science and Technology) within the CISTER Research Unit (CEC/04234); also by FCT and the EU ECSEL  ... 
doi:10.1109/vtcspring.2018.8417722 dblp:conf/vtc/Samano-Robles18 fatcat:p4v6x5gvtvfe3nitmo25eltgyq

Stability and Delay of NDMA-MPR Protocol in Rice-Correlated Channels with Co-Channel Interference

Ramiro Sámano-Robles
2019 Technologies  
This paper investigates backlog retransmission strategies for a class of random access protocols with retransmission diversity (i.e., network diversity multiple access or NDMA) combined with multiple-antenna-based  ...  The results suggest that NDMA-MPR can achieve very low values of latency that can guarantee real- or near-real-time performance for multiple access in 5G, even in scenarios with high correlation and moderate  ...  The last epoch shows that two non-backlogged terminals experience a successful collision resolution.  ... 
doi:10.3390/technologies7010022 fatcat:peetzadaczf2ngurkuzzzcu4g4

LTE/LTE-A Random Access for Massive Machine-Type Communications in Smart Cities [article]

Md Shipon Ali, Ekram Hossain, Dong In Kim
2016 arXiv   pre-print
To this end, we propose a novel collision resolution random access model for massive MTC over LTE/LTE-A.  ...  In case of massive random access attempts, the probability of preamble collision drastically increases, thus the performance of LTE/LTE-A random access degrades sharply.  ...  The general algorithm of our proposed CRB-RA model for two different collision thresholds is presented as follows: Algorithm: Collision resolution based random access. 1.  ... 
arXiv:1608.03042v1 fatcat:isf4gsmmcfd25jq46egssonkoe

On the Sum-Rate of Contention Resolution in Massive MIMO with NOMA

Hebert Douglas Pereira, Glauber Brante, Jamil Farhat, Richard Demo Souza, Jose Carlos Marinello, Taufik Abrao
2021 IEEE Access  
INDEX TERMS Massive MIMO, strongest-user collision resolution, non-orthogonal multiple-access.  ...  (SUCRe) protocol is modified to include a non-orthogonal multiple access (NOMA) approach.  ...  when compared to orthogonal multiple access (OMA) [27] .  ... 
doi:10.1109/access.2021.3055579 fatcat:5gldynexpnaivhfvk4z3hx4kse

Non-Orthogonal Random Access (NORA) for 5G Networks [article]

Yanan Liang, Xu Li, Jiayi Zhang, Zhiguo Ding
2017 arXiv   pre-print
Motivated by the key idea of non-orthogonal multiple access, the non-orthogonal random access (NORA) scheme based on successive interference cancellation (SIC) is proposed in this paper to alleviate the  ...  However, the potential large random access (RA) delay calls for a new RA scheme and for a detailed assessment of its performance.  ...  Motivated by the key idea of non-orthogonal multiple access, the non-orthogonal random access (NORA) scheme based on successive interference cancellation (SIC) is proposed in this paper to alleviate the  ... 
arXiv:1705.01235v1 fatcat:kh4vm426gzbmpnoytshmak7nmu

Stability Properties of Network Diversity Multiple Access with Multiple-Antenna Reception and Imperfect Collision Multiplicity Estimation

Ramiro Samano-Robles, Atilio Gameiro
2013 Journal of Computer Networks and Communications  
By using this retransmission diversity approach for collision resolution, NDMA is the family of random access protocols with the highest potential throughput.  ...  of random access protocols.  ...  e estimation of the collision multiplicity can be improved by exploiting the new retransmissions received in subsequent time slots within the collision resolution period.  ... 
doi:10.1155/2013/984956 fatcat:qxomzejs5vbl3eiubmgiyrymm4

Admission Control based Traffic-Agnostic Delay-Constrained Random Access (AC/DC-RA) for M2M Communication [article]

H. Murat Gürsu, Mikhail Vilgelm, Alberto M. Alba, Matteo Berioli, Wolfgang Kellerer
2019 arXiv   pre-print
We achieve this with an admission control decision that uses a novel collision estimation algorithm for active number of arrivals per contention resource.  ...  The solution of this problem demands a delay constrained random access protocol. To this end we propose Admission Control based Traffic Agnostic Delay Constrained Random Access (AC/DC-RA) protocol.  ...  This enables guarantees for traffic agnostic stochastic delay constraints for random access. 2) A novel scalable collision multiplicity estimator is provided that is based on the famous Coupon Collector's  ... 
arXiv:1903.11320v1 fatcat:24tghufrdfczvfk5y5l2ff2jxa

Enabling LTE RACH Collision Multiplicity Detection via Machine Learning [article]

Davide Magrin, Chiara Pielli, Cedomir Stefanovic, Michele Zorzi
2018 arXiv   pre-print
The collision resolution mechanism in the Random Access Channel (RACH) procedure of the Long-Term Evolution (LTE) standard is known to represent a serious bottleneck in case of machine-type traffic.  ...  Most importantly, our scheme can also estimate the collision multiplicity, and thus gather information about how many devices chose the same preamble.  ...  Multiple root sequences are considered in [7] , which proposes a preamble detector able to identify non-orthogonal preambles and suppress the noise rise.  ... 
arXiv:1805.11482v1 fatcat:f4vaosuzbjf63lkxziqevdj6iq

DAC: Distributed Asynchronous Cooperation for Wireless Relay Networks

Xinyu Zhang, Kang G. Shin
2010 2010 Proceedings IEEE INFOCOM  
The receiver then extracts multiple versions of each relayed packet via a collision-resolution algorithm, thus realizing the diversity gain of cooperative communication.  ...  Considering the use of DAC for multiple network flows, we analyze the fundamental tradeoff between the improvement in diversity gain and the reduction in multiplexing opportunities.  ...  , thus allowing for collision resolution at the PHY.  ... 
doi:10.1109/infcom.2010.5461940 dblp:conf/infocom/ZhangS10 fatcat:qur55abxvbh2dd57szpfygvvuy

Massive MIMO for Internet of Things (IoT) Connectivity [article]

Alexandru-Sabin Bana, Elisabeth de Carvalho, Beatriz Soret, Taufik Abrão, José Carlos Marinello, Erik G. Larsson, Petar Popovski
2019 arXiv   pre-print
This paper fills this important gap by identifying the opportunities and challenges in exploiting massive MIMO for IoT connectivity.  ...  In this paper we investigate the applicability of massive MIMO to IoT connectivity.  ...  Another approach of solving the activity detection and collision resolution is the grant-based strongest-user collision resolution (SUCR) protocol described in [14] .  ... 
arXiv:1905.06205v1 fatcat:xqe2z6evhrc27cvtxad5iiko4a

An Intelligent Load Control-Based Random Access Scheme for Space-Based Internet of Things

Changjiang Fei, Bin Jiang, Kun Xu, Lei Wang, Baokang Zhao
2021 Sensors  
Random access is one of the most competitive multiple access schemes for future space-based Internet of Things (S-IoT) due to its support for massive connections and grant-free transmission, as well as  ...  collision.  ...  Non-Orthogonal Multiple Access In order to overcome the above-mentioned problems of orthogonal multiple access, a series of non-orthogonal multiple access (NOMA) schemes have been proposed for massive  ... 
doi:10.3390/s21041040 pmid:33546348 fatcat:z3oc5xmuhfc4vhzhdsoqowlzie

Hashing Backoff: A Collision-Free Wireless Access Method [chapter]

Paul Starzetz, Martin Heusse, Franck Rousseau, Andrzej Duda
2009 Lecture Notes in Computer Science  
In this paper, we propose Hashing Backoff, an access method in which stations select backoff values by means of asymptotically orthogonal hashing functions, so that contending stations converge to a collision-free  ...  This solution is a half-way between TDMA, CDMA, and random access.  ...  Other channel allocation schemes rely on dynamic random access such as the familiar CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) that allows stations to operate in a fully distributed way  ... 
doi:10.1007/978-3-642-01399-7_34 fatcat:cz4masjlrndytkqv2cg7eldw7e

Multichannel random access in OFDMA wireless networks

Young-June Choi, Suho Park, Saewoong Bahk
2006 IEEE Journal on Selected Areas in Communications  
However, traditional random access schemes could result in an excessive amount of access delay.  ...  OFDMA systems are considered promising candidates for implementing next generation wireless communication systems. They provide multiple channels that can be accessed via random access schemes.  ...  Shroff for their invaluable discussions.  ... 
doi:10.1109/jsac.2005.862422 fatcat:53pf2dhribauvgzf6vj5ejmaha

Random Beam-Based Random Access for Low-Latency Device-to-Device Communication Systems

Jung Hoon Lee, Yunjoo Kim, Il-gu Lee
2020 IEEE Access  
In our proposed protocol, the user adopts the orthogonal random beams both for reception and transmission regardless of channel conditions.  ...  Moreover, the user of random beamforming can reduce the computational complexity and time delay for beamforming.  ...  The authors of [13] considered time-division multiple access (TDMA) based satellite networks and proposed random access with a non-orthogonal slotted Aloha protocol.  ... 
doi:10.1109/access.2020.2990448 fatcat:cvdkpegmo5cprhstwldxis4feq
« Previous Showing results 1 — 15 out of 5,719 results