This paper proposes and analyzes a downlink multi-antenna multi-user system with rate-splitting multiple access (RSMA) scheme. In this framework, we consider the error probability when the base station (BS) transmits both long and short packet information to multiple cell-edge users. Our approach begins with the beamforming vector analysis, and employs the cumulative distribution functions (CDF) of signal-interference noise ratio (SINR). To map the dependencies of common and private streams of RSMA for the SINR, we adopt a two-dimensional signal constellation, which revealed the relationship between power allocation factors and modulation types. This relationship affects the decision boundaries of the modulation schemes. To evaluate the system performance, exact and asymptotic expressions for the block error rate (BLER) and bit error rate (BER) are derived over Nakagami fading channels. The optimal power allocation coefficient to minimize BLER under varying channel uses is formulated and detected through optimization problem and numerical results. Fairness in BER among all users is considered by accounting for the number of antennas and the adopted power allocation strategy. The advantages of RSMA are further verified through comparisons of BLER/BER with non-orthogonal multiple access (NOMA) systems. These findings underscore the potential of RSMA to significantly enhance reliability. The derived expressions are tractable, validated through comparisons with Monte Carlo simulation results, and offer reduced computational complexity and faster execution compared to the simulation-based outcomes. The results show the closest alignment between simulations and the derived analytical expressions.

This paper investigates the secrecy performance of a hardware-impaired secure rate-splitting multiple access (HIS-RSMA) network in multi-user multiple-input single-output (MISO) Internet of Things (IoT) scenarios over Nakagami-mfading channels. Closed-form expressions for the secrecy capacity (SC) and secrecy outage probability (SOP) are derived and validated through Monte-Carlo simulations. The proposed analytical framework explicitly accounts for the joint effects of non-ideal hardware (NIH), imperfect successive interference cancellation (SIC), and imperfect channel state information (CSI), thereby providing a realistic evaluation of secrecy in IoT networks. Numerical results reveal that NIH has a negligible impact on the secrecy of the common message but significantly degrades the secrecy of private messages at high transmit powers. Moreover, both NIH and imperfect SIC introduce non-vanishing SOP error floors, while imperfect CSI at the eavesdropper can substantially enhance secrecy. The number of transmit antennas and the operating frequency are also shown to critically influence secrecy performance. Overall, the findings highlight that HIS-RSMA is a promising solution for secure and efficient transmission in IoT networks, underscoring the need for joint optimization of transceiver design, antenna configuration, and physical-layer security strategies in beyond fifth-generation (B5G) wireless systems.

This paper considers and analyzes the performance of a non-orthogonal multiple access (NOMA) system using finite-size data packets with the assistance of active reconfigurable intelligent surfaces (ARISs) mounted on an unmanned aerial vehicle (UAV). This work aims to enhance communication efficiency in scenarios that require low latency and high reliability. The exact and asymptotic closed-form expressions for the block error rate (BLER) and average achievable rate (AAR) of the considered UAV-ARIS-NOMA system with short packet communication under imperfect successive interference cancellation (SIC) are derived. The results analysis indicates that the number of reflection elements strongly influences the diversity order. The considered system meets ultra-reliable and low-latency communications (URLLC) demands with 99.999% reliability, and the ARIS model's BLER reduces by 290% compared to the passive RIS (PRIS). Moreover, the gap between the AAR of ARIS and PRIS is up to 40% when configuring eight reflection elements. The system's AAR reaches saturation by adjusting the ARIS amplification factor to three power units. When channel uses exceed 300, the system's transmission rate meets the Shannon rate. Moreover, simulation results are introduced to verify the theoretical analysis and offer insights into optimizing power allocation and UAV altitude to minimize BLER.

This paper proposes a secure wireless system that integrates rate-splitting multiple access (RSMA), intelligent reflecting surfaces (IRS), and full-duplex relaying (FDR) to enhance secrecy performance against multiple colluding eavesdroppers. Closed-form expressions for the secrecy outage probabilities (SOPs) and average secrecy capacities (ASCs) of both common and private messages are derived. Comparative analysis with a baseline RSMA-FDR system (without IRS) demonstrates the benefits of IRS in improving secrecy. Numerical results reveal that RSMA-IRS-FDR achieves superior secrecy performance, with SOPs and ASCs strongly influenced by transmission power, particularly differing between message types. Moreover, the adverse effect of residual self-interference (RSI) is substantially mitigated in the IRS-aided system. The secrecy performance is further enhanced by increasing the number of IRS elements. The study also investigates the impact of key parameters such as power allocation, target secrecy rate, fading order, Wi-Fi frequency, and number of eavesdroppers, offering practical insights for secure RSMA-IRS-FDR system design.

In this paper mathematically studies utilizing finite block length in a full-duplex (FD) relay network with multiple antennas and non-orthogonal multiple access (NOMA). Specifically, the block error rate (BLER) and age-of-information (AoI) of the investigated system with residual self-interference and imperfect successive interference cancellation are derived. Moreover, the power allocation coefficient is optimized to minimize the average BLER and the influences of various parameters on system's performance are examined. We enhance the BLER and AoI performance by employing the maximal-ratio combining and maximal-ratio transmission techniques at multiple antennas of source and destination nodes. Simulation results validate our analytical frameworks. Numerical results indicate that employing multi-antennas for a NOMA system with FD relay gives exceptionally low average BLER that fulfils the targets of high reliability and latency of the wireless systems. Furthermore, the optimal AoI of the investigated system can be achieved by selecting a suitable block length. In particular, the minimum AoI is obtained when SNR = 10 dB and the block length is 300. Also, the average BLER and average AoI of the considered NOMA-FD system outperform conventional orthogonal multiple access and half-duplex (HD) systems. Especially when the block length is less than 250, the AoI of the FD system is reduced by 90% compared to that of the HD system.

This paper analyzes and solves the optimization problem of the performance of a multi-antenna unmanned aerial vehicle (UAV)-aided NOMA multi-user pairing system. Based on the approximation of the Gaussian-Chebyshev quadrature and incomplete Gamma function, we successfully derive the exact and asymptotic closed-form expressions for the block error rate, throughput, and goodput of the system. Moreover, we also provide other metrics such as the latency, reliability, and age of information (AoI). The results indicate that the considered system meets the requirements of ultra-reliable and low-latency communications (URLLC). Particularly, its reliability is higher than 99.99% and latency is less than 1 ms. The optimization of the UAV's altitude, block length, and the number of transmission bits to maximize the throughput and minimize the latency and AoI of the considered system is also studied by using iterative algorithms. Furthermore, we propose an algorithm to optimize the transmission power of UAVs to maximize the system's energy efficiency. The greedy algorithm is used to schedule paired users and achieves better performance compared to the random schedule. Moreover, applying multiple antennas and maximum ratio transmission can significantly improve the latency and AoI performance of the considered system. The accuracy of analytical frameworks is verified by simulation results.

This article proposes an integration of multiple reconfigurable intelligent surfaces (RISs) with a relay to enhance the performance of a low-power wide-area (LPWA) network. Specifically, besides using the traditional relaying approach to assist the transmission between an Internet of Things (IoT) sensor and a gateway, multiple RISs are also utilized to boost the intermediate links between the IoT sensor and the relay and between the relay and the gateway. We mathematically derive the analytical expressions of average outage probability (AOP) and average symbol error probability (ASEP) of this multiple-RIS-relay aided LPWA network over Nakagami-$m$fading channels. The performance of the proposed network is also compared with the performance of the relay-aided LPWA network without using RISs. The analytical results show that the exploitation of RISs can greatly enhances the performance of the LPWA network. Thus, the multiple-RIS-relay aided LPWA network can operate at the high frequency band for long range transmission. Moreover, the effect of various important factors such as the location of the RISs, the Nakagami-$m$parameters, the data transmission rate, and the modulation scheme on the performance of the multiple-RIS-relay aided LPWA network are also investigated in practical scenarios.

In this paper, the performance of a wireless system, which is beneficial from utilization of multiple reconfigurable intelligent surfaces (RISs) and the direct link between the source node and the mobile user, is analyzed. Especially, the effect of transceiver hardware impairments (HIs) are taken into consideration. We successfully derive the outage probability (OP), throughput, achievable data rate (ADR), and symbol error probability (SEP) expressions of this multiple-RIS assisted wireless systems with and without HIs (referred as RIS-HI and RIS-ID system, respectively) over Nakagami-$m$fading channels. The above performance factors are also benchmarked with the case that only a point-to-point (P2P) link without RIS is considered (denotes as as P2P-HI and P2P-ID systems for HI and ideal hardware conditions, respectively). All obtained formulas are verified by Monte-Carlo simulations. It is observed that the RIS-HI system significantly outperforms the P2P-HI system at low transmit power regime, while the performance of the RIS-ID system is always better than that of P2P-ID system. On the other hand, HIs show more severe effect for higher data transmission rates or high modulation orders.

In this paper, we investigate the performance of a full-duplex (FD) relay system where multi-antennas are exploited at source and destination. Unlike previous works, the impacts of imperfect channel state information (I-CSI), transceiver hardware noise (THN), and residual self-interference (RSI) are taken into account. We mathematically derive the exact closed-form expressions of the outage probability (OP), symbol error rate (SER), and ergodic capacity (EC) of the FD relay system with I-CSI, THN, and RSI over Nakagami-$m$fading channels. From the derived expressions, the performance of the considered system under the effects of three negative factors (I-CSI, THN, and RSI) is compared with that system in the case of all ideal factors (perfect channel state information (P-CSI), perfect transceiver hardware (P-TH) and perfect self-interference cancellation (P-SIC)), two ideal factors (P-CSI and P-TH, P-CSI and P-SIC, P-TH and P-SIC), or one ideal factor (P-CSI or P-TH or P-SIC). Numerical results show a strong impact of three negative factors on the OP, SER, and EC of the considered FD relay system, especially when the data transmission rate of the system and signal-to-noise ratio (SNR) are high. In particular, OP, SER, and EC go to the floors in the high SNR regime due to the three negative factors. Therefore, when I-CSI, THNs, and RSI exist in the FD relay system, we should use suitable source and relay transmission power to obtain excellent performance while saving energy consumption. Moreover, when two of the three negative factors are large enough, the remaining factor’s impact becomes weaker and may be neglected in certain circumstances.

This paper studies the ergodic capacity (EC) of full‐duplex (FD) amplify‐and‐forward (AF) and decode‐and‐forward (DF) relay system with energy harvesting (EH) for vehicle‐to‐vehicle (V2V) communications. Unlike previous works on FD‐EH systems, we consider the case that both relay and destination are mobile vehicles while the source is a static base station. We mathematically derive the exact closed‐form expressions of ECs of both AF and DF protocols of the considered FD‐EH‐V2V relay system over cascade (double) Rayleigh fading. Our numerical results show that the ECs in the case of the V2V communication system are reduced compared to those in the case of stationary nodes. Also, with a specific value of residual self‐interference (RSI), the ECs of the considered FD‐EH‐V2V relay system can be higher or lower than those of half‐duplex‐ (HD‐) EH‐V2V system, depending on the average transmission power of the source. Furthermore, when the transmission power of the source and RSI are fixed, the ECs of the considered system can achieve peak values by using optimal EH time duration. On the other hand, the ECs of both AF and DF protocols reach the capacity floors in the high signal‐to‐noise ratio (SNR) regime due to the RSI impact. Also, the effect of RSI dominates the impact of cascade Rayleigh fading in the high SNR regime. Finally, we validate our analysis approach through Monte‐Carlo simulations.

In this paper, we evaluate the performance of a vehicle-to-vehicle (V2V) system where full-duplex relay (FDR) harvests the energy from source and uses decode-and-forward (DF) protocol to forward data from source to destination. Unlike existing works about FDR systems, we consider the scenario that both relay and destination are moving vehicles, leading to the channel between relay and destination characterized by double (cascade) Rayleigh fading. We successfully obtain the closed-form mathematical expressions of the outage probability (OP) and throughput of the considered energy harvesting- (EH-) FDR-V2V system. Based on these expressions, the system performance is investigated through various scenarios. Numerical results indicate that the performance of the considered system is reduced compared with that of the system over Rayleigh fading channels. We also observe that there is an optimal EH time duration that minimizes the OP and maximizes the throughput. This value depends on the transmission power of source. Furthermore, the OP goes to outage floor faster due to the impact of the residual self-interference (RSI), especially when RSI is high. All analysis results are verified by Monte-Carlo simulations.

In this paper, we analyze the performance of in-band full-duplex (IBFD) relay systems that use the decode-and-forward (DF) protocol at the relay under the impact of imperfect self-interference cancellation and hardware impairments. Three practical relay scenarios are considered in our analysis: (i) there is no direct link from the source to the destination; (ii) there is a direct link, but the signal from the source is considered interference; and (iii) there is a direct link, and the signal from the source is cooperatively combined with that from the relaying path. Specifically, we derive exact and asymptotic expressions for the outage probability (OP) of the IBFD system. Based on the OP, the exact expression for symbol error probability (SEP) is also derived. Moreover, in order to cope with the effect of imperfect self-interference cancellation (SIC) due to the full-duplex mode, we propose optimal and suboptimal power calculation methods for the relay to minimize the OP and SEP. A performance evaluation shows that the IBFD relay system is significantly affected by both imperfect SIC and hardware impairments. However, the optimal power values can help to improve the system performance, significantly.

In this paper, a combination of energy harvesting (EH) and cooperative nonorthogonal multiple access (NOMA) has been proposed for full-duplex (FD) relaying vehicle-to-vehicle (V2V) networks with two destination nodes over a Rayleigh fading channel. Different from previous studies, here both source and relay nodes are supplied with the energy from a power beacon (PB) via RF signals, and then use the harvested energy for transmitting the information. For the extensive performance analysis, the closed-form expressions for the performance indicators, including outage probability (OP) and ergodic capacity of both users, have been derived rigorously. Additionally, the effect of various parameters, such as EH time duration, residual self-interference (RSI) level, and power allocation coefficients, on the system performance has also been investigated. Furthermore, all mathematical analytical results are confirmed by Monte-Carlo simulations, which also demonstrate the optimal value of EH time duration to minimize the OP and maximize the ergodic capacity of the proposed system.

In this paper, we analyze the performance of a full-duplex (FD) amplify-and-forward (AF) relay system with imperfect hardware. Besides the aggregate hardware impairments of the imperfect transceiver, we also consider the impact of residual self-interference (RSI) due to imperfect cancellation at the FD relay node. An analytical framework for analyzing the system performance including exact outage probability (OP), asymptotic OP, and approximate symbol error probability (SEP) is developed. In order to tackle these impacts, we propose an optimal power allocation scheme which can improve the outage performance of the FD relay node, especially at the high signal-to-noise ratio (SNR) regime. Numerical results are presented for various evaluation scenarios and verified using the Monte Carlo simulations.