scholarly journals Asynchronous Flipped Grant-Free SCMA for Satellite-Based Internet of Things Communication Networks

2019 ◽  
Vol 9 (2) ◽  
pp. 335 ◽  
Author(s):  
Pengxu Li ◽  
Gaofeng Cui ◽  
Weidong Wang
Keyword(s):  
Internet Of Things ◽  
Communication Networks ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Satellite Communication ◽  
Time Synchronization ◽  
Sliding Window ◽  
Loss Ratio ◽  
Access Scheme ◽  
Code Domain

Sparse code multiple access (SCMA) is a promising code domain non-orthogonal multiple-access scheme which is able to support massive connectivity and grant-free transmission in future satellite-based Internet of Things (IoT) communication networks. Traditional grant-free SCMA is based on time synchronization, which is no longer favorable in such satellite communication networks since the amount of signaling generated to keep all transmitters’ time synchronized is impractical for large networks. Moreover, without centralized codebook assignment, grant-free SCMA suffers from codebook collisions which mean more than one terminal selecting the same codebook being interfered. Motivated by these issues, a novel uplink grant-free asynchronous flipped SCMA scheme named AF-SCMA is proposed in this paper. With the concept of flipped diversity, a specific SCMA-encoded packet is transmitted with its flipped replica together. Successive interference cancellation technique combined with a sliding window is adopted to resolve the packet collisions including codebook collisions at the gateway station. The performance of AF-SCMA is investigated via both mathematical analysis and simulations. Simulation results show that the proposed AF-SCMA provides remarkable performance in terms of throughput and packet loss ratio (PLR), and can benefit from the received signal power unbalance.

scholarly journals Intelligent reflected surfaces assisted code domain non-orthogonal multiple access scheme

2021 ◽  
Vol 72 (5) ◽  
pp. 343-347
Author(s):  
Aasheesh Shukla
Keyword(s):  
Communication Networks ◽  
Information Transfer ◽  
Multiple Access ◽  
Wireless Communication Networks ◽  
Radio Waves ◽  
Reflection And Refraction ◽  
Access Scheme ◽  
Code Domain ◽  
Efficient Code ◽  
Phase Amplitude

Abstract The propagation medium plays a crucial role in any wireless communication networks, the channel between the transmitter and the receiver, deteriorate the quality of the received signal due to the uncontrollable interactions such as scattering, reflection, and refraction in the channel with the surrounding objects. To overcome this challenge, the recent advent of recongurable intelligent surfaces can be helpful, in which the network operators can control the radio waves, eg, the phase, amplitude, frequency, and even polarization, of the impinging signals without the need of complex decoding, encoding, and radio frequency processing operations. On the other hand, few research papers reported an efficient code domain non orthogonal multiple access (NOMA) such as Interleave division multiple access (IDMA) system for wireless information transfer. Persuaded by the capability of this arising RIS technology, the present article is aimed to provide the modified framework of IDMA (code-domain NOMA) communication system based on RIS technology. Simulation results demonstrate that the proposed system achieves better SNR performance than the conventional IDMA framework.

scholarly journals Joint RSMA and IDMA-Based NOMA system for downlink Communication in 5G and Beyond Networks

2020 ◽  
Vol 16 (4) ◽  
pp. 324-329
Author(s):  
Aasheesh Shukla
Keyword(s):  
Communication Networks ◽  
Multiple Access ◽  
Heterogeneous Data ◽  
Broadcast Channels ◽  
Data Traffic ◽  
Access Scheme ◽  
Wide Range ◽  
Rate Splitting ◽  
Code Domain ◽  
Weighted Sum Rate

Future communication networks may encounter various issues in order to facilitate heavy heterogeneous data traffic and large number of users, therefore more advanced multiple access (MA) schemes is required to meet the changing requirements. Recently, a promising physical-layer MA technique has been suggested for multi-antenna broadcast channels, namely Rate Splitting Multiple Access (RSMA). This new scheme has the ability to partially decode the interference and partially treat the remaining interference as noise which makes it to cope with wide range of user deployments and network loads. On the other hand, interleave division multiple access (IDMA) has already been recognized as a potential code domain NOMA (non-orthogonal multiple access) scheme, suitable for 5G and beyond communication network. Hence, in this paper, a new approach of multiple access scheme is proposed to get the grip on new challenges in future communication (6G). The proposed framework consists the joint processing of RSMA and IDMA (code domain NOMA), in which the transmitter involves an IDMA as encoder and allows rate splitting to split the message in two parts i.e. common part and private part, before the actual transmission. The mathematical modeling of proposed system is elaborated in the paper and for simulation purpose the downlink communication scenario has been considered where users faced diverse channel conditions. The weighted sum rate (WSR) performance is evaluated for the proposed scheme which validate the quality of service (QoS) of the joint RS-IDMA system.

scholarly journals CSNOMA: Carrier Sense Non-Orthogonal Multiple Access

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5024
Author(s):  
Dong Min Kim ◽  
Seong-Lyun Kim
Keyword(s):  
Interference Cancellation ◽  
Multiple Access ◽  
Random Access ◽  
Cross Layer Design ◽  
Carrier Sense Multiple Access ◽  
Mac Layers ◽  
802.11 Dcf ◽  
Carrier Sense ◽  
Access Scheme ◽  
Multiple Access Protocol

In this paper, we investigate the possibility of the cross-layer design of a distributed random access scheme with considering physical (PHY) and multiple access control (MAC) layers, which utilizes the interference cancellation technique. In this regard, we propose a new multiple access protocol, named carrier sense non-orthogonal multiple access (CSNOMA). We consider the spatially randomly distributed interferers to realistically capture the effect of interference. The proposed protocol shows better area spectral efficiency than carrier sense multiple access (CSMA), as the node density increases. We also present a practical signaling design compatible with IEEE 802.11 DCF mode.

scholarly journals The Application of Power-Domain Non-Orthogonal Multiple Access in Satellite Communication Networks

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 63531-63539 ◽  
Author(s):  
Xiaojuan Yan ◽  
Kang An ◽  
Tao Liang ◽  
Gan Zheng ◽  
Zhiguo Ding ◽  
...  
Keyword(s):  
Communication Networks ◽  
Multiple Access ◽  
Satellite Communication ◽  
Power Domain

scholarly journals Code Domain Non- Orthogonal Multiple Access Schemes for 5G and Beyond Communication Networks: A Review

2021 ◽  
Author(s):  
Aasheesh Shukla ◽  
◽  
Manish Kumar ◽  
Vinay Kumar Deolia ◽  
◽  
...  
Keyword(s):  
Communication Networks ◽  
Multiple Access ◽  
Heterogeneous Data ◽  
Data Traffic ◽  
5G Networks ◽  
Comprehensive Overview ◽  
Power Domain ◽  
Rate Splitting ◽  
Code Domain ◽  
Multiple Access Schemes

Future communication networks may encounter various issues in order to facilitate heavy heterogeneous data traffic and large number of users, therefore more advanced multiple access (MA) schemes are being developed to meet the changing requirements. The research space on making more robust MA scheme is continuously increasing, so it becomes significant to analyze the various schemes to determine the appropriate MA scheme for 5G networks. Therefore, in this paper the comprehensive overview of the most popular and recent MA schemes is presented for 5G networks. This paper mainly classifies the MA techniques in orthogonal MA (OMA) and various types of non-OMA (NOMA) techniques. Specifically, we introduce RSMA (Rate splitting multiple access) and IDMA (interleave division multiple access). Further the close attention is paid to NOMA family, including code-domain NOMA (e.g., SCMA (sparse code multiple access)), power-domain NOMA. Above all, from this exploration, the opportunities and challenges could be notified in MA schemes and further the optimum MA technique can be point out among discussed MA schemes for 5G and beyond communication networks.

scholarly journals Effects of Power Allocation and User Mobility on Non-Orthogonal Multiple Access Using Successive Interference Cancellation

ELKHA ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Khoirun Niamah ◽  
Solichah Larasati ◽  
Raudhatul Jannah
Keyword(s):  
Power Allocation ◽  
High Power ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Successive Interference Cancellation ◽  
Channel Gain ◽  
User Mobility ◽  
Power Domain ◽  
Code Domain

This research based on simulation to show impact of the power allocation on Non-Orthogonal Multiple Access (NOMA) using Successive Interference Cancellation (SIC). NOMA used superposition code (SC) on the transmitter and SIC on the receiver. NOMA has two categories power domain (PD) and code domain (CD). This research based on PD-NOMA simulated for downlink. The number of users who use the same recourse block are divided into two conditions: user with apply SIC and without SIC base on the value of channel gain from each user. Applying SC on the transmitter and SIC on the receiver will cancel of interference. Novelties of this research are the best performance of power allocation and user mobility based on parameter BER and SNR. Allocation of the power transmit based on value of channel gain every user, where user with value of channel gain is low will be allocated high power transmit, and otherwise. The best result performance of BER vs SNR used ratio power transmit 0.45 dB:0.55 dB, BER  get value SNR for 17 dB and  18 dB. The best performance SNR for mobility of user with speed    = 40 km/h value SNR 18 dB for BER . This research has proposed to show impact of power transmit and interference in performance NOMA.

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