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

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.

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

Journal of Engineering Research ◽

10.36909/jer.10875 ◽

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.

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

Journal of Electrical Engineering ◽

10.2478/jee-2021-0048 ◽

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.

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

Applied Sciences ◽

10.3390/app9020335 ◽

2019 ◽

Vol 9 (2) ◽

pp. 335 ◽

Cited By ~ 3

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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