Nonorthogonal multiple access systems optimization to ensure maximum fairness to users

Non‐orthogonal multiple access (NOMA) technology is a key technology of the future cellular mobile communication system. It provides services for users under different channel conditions through signal superposition transmission and spectrum multiplexing. Pattern division multiple access (PDMA) is a new NOMA technology based on the overall optimization of multi‐user communication system. Since the performance of PDMA mainly depends on the gain of the pattern matrix, we propose a design scheme of uplink PDMA pattern matrix for ultra‐reliable low latency communication (uRLLC). For the interference between users is a common problem in NOMA system, first, we use poly complementary sequence (PCS) as the spread codebook to spread the PDMA transmission signal and reduce interference. Meanwhile, an uplink power control scheme is proposed. It allocates wireless resources reasonably by jointly considering the interference between users and resource blocks within users (JUR), the corresponding outage probability formula is also derived. Simulation results show that compared with the previous researches, the pattern matrix design scheme and JUR power control scheme proposed in this article have greatly improved the transmission performance. The addition of PCS spread spectrum technology can significantly reduce the block error rate and outage probability.

Section: Introductionmentioning

confidence: 99%

Uplink grant‐free pattern division multiple access transmission scheme by exploiting poly complementary sequence

Sun

et al. 2021

“…NOMA is a developing multiple access method that is a vital player in B5G owing to channel capacity achievements 3‐5 . Various signals are superimposed based on different power levels at the transmitter end maintaining the same time and frequency in a NOMA system, and this is the main aspect that differentiates the NOMA system from existing multiple access systems, such as the orthogonal multiple access (OMA) system 5,6 . Detailed classifications and challenges of NOMA are discussed in Reference 5.…”

Section: Introductionmentioning

confidence: 99%

“…Detailed classifications and challenges of NOMA are discussed in Reference 5. Moreover, a suitable optimization to ensure maximum fairness to the NOMA users in Reference 6. Subsequently, successive interference cancellation (SIC) must be performed to decode individual signals at the receiver 1‐8 .…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, a suitable optimization to ensure maximum fairness to the NOMA users in Reference 6. Subsequently, successive interference cancellation (SIC) must be performed to decode individual signals at the receiver 1‐8 . NOMA may be enforced in a vast field of applications in case of B5G wireless communication system 5,6,9 .…”

Section: Introductionmentioning

confidence: 99%

“…Subsequently, successive interference cancellation (SIC) must be performed to decode individual signals at the receiver 1‐8 . NOMA may be enforced in a vast field of applications in case of B5G wireless communication system 5,6,9 . Cooperative NOMA (CNOMA) is a wide research area that can improve the wireless network system's capacity and reliability of a wireless network by users cooperate relay or dedicated relay 10‐15 .…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Performance analysis of cooperative nonorthogonal multiple access with improved time switching simultaneous wireless information and power transfer protocol

Amin

Shin

2020

In this study, improved time switching (ITS) simultaneous wireless information and power transfer (SWIPT‐ITS) protocol along with cooperative nonorthogonal multiple access (CNOMA) downlink (DL) transmission are integrated (termed as CNOMA‐SWIPT‐ITS) for DL transmission. CNOMA‐SWIPT‐ITS scheme transfers information to the users and performs energy harvesting (EH) for relay operation from cell center user (CCU) to cell edge user (CEU). Furthermore, the scheme transfers different symbols using the time duration of EH at the CCU and performs cooperative relaying (CCU to CEU) to enhance the channel capacity of the users. The performance of CNOMA‐SWIPT‐ITS scheme is measured in terms of ergodic sum capacity and outage probabilities. Finally, simulation and analytical results demonstrate the superiority of the proposed scheme over conventional CNOMA based SWIPT schemes and typical orthogonal multiple access based ITS SWIPT scheme.

Power control scheme for device‐to‐device communication using uplink channel in 5G mm‐Wave network

Sarma

Khuntia

Hazra

2021

Mm-Wave communication ushers next-gen communication to new heights guaranteeing higher speed and throughput. Enabling device-to-device (D2D) communication in next-gen wireless communication is a Herculean task. This is due to introduction of pathloss attenuation by various environmental factors which deteriorates the signal. This article aims to minimize the effect of interference for quality reception of signals for D2D communication and increase system throughput. Thus, a power control scheme is proposed in underlay mode for uplink channel in mm-Wave band. Here, D2D communication takes place through two modes namely, general mode and mm-Wave mode. In presence of large number of proximity D2D users and increasing pathloss attenuation, it switches to mm-Wave mode for communication. The formulated problem is converted to semiconvex form by expressing it into exponential form in Laplace domain. Our final objective is to maximize the energy efficiency (EE) of the proposed system under certain constraints. To reduce complexity of the problem, feasible regions of transmission power is introduced, that is, least and upper bounds which will ensure that power is maintained within a limit guaranteeing better throughput for D2D users. Enhanced EE and outage probability values also depict better performance of proposed system. Finally, fairness index (FI) shows that the proposed scheme yields better performance for the D2D users to communicate in the mm-Wave band. A detailed comparison of FI for the proposed scheme is also done with other existing methods to prove the adequate performance of the proposed method. Simulation results also prove the efficacy of the proposed scheme.