scholarly journals Dynamic Space-Code Multiple Access (DSCMA) System: A Double Interference Cancellation Multiple Access Scheme in Wireless Communications System

10.5772/8501 ◽  
2010 ◽  
Author(s):  
Chee Kyun ◽  
Nor Kamariah ◽  
Borhanuddin Mohd ◽  
Sudhanshu Shekhar
Keyword(s):  
Wireless Communications ◽  
Interference Cancellation ◽  
Multiple Access ◽  
System A ◽  
Access Scheme ◽  
Communications 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 GPU Accelerated PIC and SIC for OFDM-NOMA

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 257 ◽  
Author(s):  
Talgat Manglayev ◽  
Refik Kizilirmak ◽  
Nor Hamid
Keyword(s):  
Interference Cancellation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Access ◽  
Graphics Processing Unit ◽  
Processing Unit ◽  
Parallel Interference Cancellation ◽  
Central Processing ◽  
Fifth Generation ◽  
Access Scheme ◽  
Graphics Processing

Non-orthogonal multiple access (NOMA) is a candidate multiple access scheme for the fifth-generation (5G) cellular networks. In NOMA systems, all users operate at the same frequency and time, which poses a challenge in the decoding process at the receiver side. In this work, the two most popular receiver structures, successive interference cancellation (SIC) and parallel interference cancellation (PIC) receivers, for NOMA reverse channel are implemented on a graphics processing unit (GPU) and compared. Orthogonal frequency division multiplexing (OFDM) is considered. The high computational complexity of interference cancellation receivers undermines the potential deployment of NOMA systems. GPU acceleration, however, challenges this weakness, and our numerical results show speedups of about from 75–220-times as compared to a multi-thread implementation on a central processing unit (CPU). SIC and PIC multi-thread execution time on different platforms reveals the potential of GPU in wireless communications. Furthermore, the successful decoding rates of the SIC and PIC are evaluated and compared in terms of bit error rate.

scholarly journals Collaborative Signal Multiple Access: A Robust Alternative to NOMA Using SIC

2021 ◽  
Author(s):  
Indu Shakya ◽  
Falah Ali
Keyword(s):  
Wireless Communications ◽  
Theoretical Analysis ◽  
Multiple Access ◽  
Numerical Results ◽  
Detection Technique ◽  
Access Scheme ◽  
User Interference

<p>This paper proposed a novel non-orthogonal multiple access scheme called CSMA that addresses some of critical shortcomings of NOMA that are the stumbling blocks for it to be considered an enabling technique for enhancing the capacity of 5G and 6G wireless communications. We provide some radical insights into the design of signals and detection technique for overcoming multi-user interference that makes it implementable in practice. We provide a sound theoretical analysis of its performance and validate the significance of numerical results.</p>

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.

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