D2D Receiver Research Articles

Robust Energy-Efficient Transmission for Wireless-Powered D2D Communication Networks

This paper considers optimal joint time, frequency, and power allocation for energy-efficient device-to-device (D2D) communications in an overlay cellular network, where multiple D2D transmitters communicate with their corresponding D2D receivers while utilizing the energy harvested from a cellular base station (BS). Due to channel estimation error and feedback delays, the channel state information (CSI) available at the transmitters is usually imperfect, which can significantly deteriorate the energy efficiency (EE) of the considered system. To mitigate the impact of imperfect CSI, we formulate a non-convex robust optimization problem for the maximization of the EE (in bits/Joule) of the system while ensuring quality of service (QoS) requirements on the minimum data rata and the minimum amount of harvested energy for cellular and D2D users, respectively. We reveal that the optimal energy-efficient D2D transmission should exhaust all the harvested energy of each D2D transmitter. Exploiting this fact, we propose an efficient iterative algorithm for obtaining the optimal solution. To strike a balance between performance and computational complexity, we further propose a low-complexity suboptimal algorithm. Simulation results show that compared with several baseline schemes, both the proposed optimal and suboptimal algorithms can significantly improve the EE of wireless-powered D2D communications under imperfect CSI. Moreover, the proposed suboptimal algorithm is close-to-optimal when the number of cellular users are small or the channel estimation error is large.

D2D Communication Underlaying Microwave and Millimeter-Wave Cellular Networks Using CIPC

D2D communication is one of the promising technologies to improve network performance through direct wireless communication between users, without, or with limited participation of the base station (BS). In this paper, we investigate the performance of D2D communication underlaying microwave ( μ-wave) and millimeter-wave (mm-wave) cellular networks using stochastic geometry. Rayleigh fading is considered to characterize the μ-wave channels in both links, while the Rician fading is used to characterize the mm-wave channel in the D2D and cellular desired link. The D2D communication is established when the losses between the D2D transmitter and the D2D receiver are lower compared to the losses that exist between the D2D transmitter and the BS receiver. On the other hand, to minimize the interference caused by the coexistence of cellular and D2D communication and increase network performance, the Channel Inversion-Based Power Control (CIPC) is studied. In this way, the Complementary Cumulative Distribution Function (CCDF) for the successful transmission is obtained. Based on the analytical and numerical results, we show an important increase in the probability of successful transmission using the CIPC and considering the channel gains condition to establish the D2D communication compared to the traditional mode in which power control is not used and no conditions are considered to establish the D2D communication.

A Nonlinear MIMO-OFDM Based Full-Duplex Cooperative D2D Communications System

Multiple input multiple output (MIMO) based orthogonal frequency division multiplexing (OFDM) has widely been used in a wireless communications system for its robustness to frequency-selective channels and better spectral efficiency. The introduction of full-duplex (FD) and device-to-device (D2D) communications, which are potential candidates of fifth-generation (5G) and beyond, further improve the spectral efficiency of MIMO-OFDM based systems. This paper proposes a novel MIMO-OFDM based FD Cooperative-D2D (C-D2D) communications system wherein a cellular user (CU) acts as an FD relay to facilitate seamless communications between D2D transmitter and receiver. The complete analytical framework is presented to analyze the end-to-end performance of the proposed system. Specifically, the closed-form expression for symbol error rate (SER) of the proposed system is derived in the presence of multipath Rayleigh fading channel and residual self-interference (RSI) due to the FD mode. Further, the performance of the system is analyzed in the presence of a nonlinear high power amplifier (HPA) which introduces the nonlinear distortion. Finally, simulation results are presented to verify the derived expressions. The results show that there is higher SER in the presence of nonlinear HPA due to nonlinear distortion, which can be reduced by increasing input back off (IBO). The presence of RSI also increases the SER at CU, which is further reduced by employing self-interference cancellation (SIC) techniques. A complete end-to-end analytical framework is designed to compare the performance of the proposed system with the conventional system with linear HPA and no RSI.

RIS-Aided Physical Layer Security With Full-Duplex Jamming in Underlay D2D Networks

This paper investigates the physical layer security and data transmission for the underlay device-to-device (D2D) networks, and considers a combination of the reconfigurable intelligent surface (RIS) and full-duplex (FD) jamming receiver for the robustness and security enhancements of the system. In the demonstrated spectrum sharing setup, the total power of the D2D networks is conceived to the transmitter and receiver to transmit a private message and emit the artificial noise (AN) signals. To prevent information leakage, a beamforming design is presented for a multi-antenna FD D2D receiver in order to suppress and inject the AN signals in the direction of legitimate users and eavesdropper, respectively. The statistical characterization of end-to-end RIS-assisted wireless channels is presented, and the achievable ergodic secrecy rate of the system is derived in novel approximate expressions. The numerical and simulation results confirm the accuracy and effectiveness of the proposed analytical framework. The results demonstrate an optimal selection of the D2D power allocations for different number of reflecting elements in terms of achievable ergodic secrecy rates of the system.

Device-to-Device Aided Cooperative Relaying Scheme Exploiting Spatial Modulation: An Interference Free Strategy.

In this paper, a novel interference free dual-hop device-to-device (D2D) aided cooperative relaying strategy (CRS) based on spatial modulation (SM) (termed D2D-CRS-SM) is proposed. In D2D-CRS-SM, two cellular users (e.g., a near user (NU) and a relay-aided far user (FU)) and a pair of D2D transmitter (D)-receivers (D) are served in two time-slots. Two different scenarios are investigated considering information reception criteria at the NU. Irrespective of the scenarios, the base station (BS) exploits SM to map information bits into two sets: modulation bits and antenna index, in phase-1. In the first scenario, the BS maps FU information as the modulation bits and NU information as antenna index, whereas modulation bits correspond to NU information and the antenna index carries FU’s information in scenario-2. The iterative-maximum ratio combining (i-MRC) technique is then used by NU and D to de-map their desired information bits. During phase-2, D also exploits SM to forward FU’s information received from BS and its own information bits to the D2D receiver D. Then, FU and D retrieve their desired information by using i-MRC. Due to exploiting SM in both phases, interference free information reception is possible at each receiving node without allocating any fixed transmit power. The performance of D2D-CRS-SM is studied in terms of bit-error rate and spectral efficiency considering M-ary phase shift keying and quadrature amplitude modulation. Finally, the efficiency of D2D-CRS-SM is demonstrated via the Monte Carlo simulation.

Social-aware spectrum sharing for D2D communication by artificial bee colony optimization

Next-generation cellular networks must handle an increasing demand for data transmission resources, which requires the study of new technologies, such as Device-to-Device (D2D) communications. D2D expands the use of resources from a location perspective, and takes advantage of the geographical proximity of users to perform data transmission at high rates and low propagation delays. On the other hand, the widespread use of social networks establishes the degree of social relations among users and facilitates the efficient management of D2D communication networks. The integration of social networks and D2D communications into 5G networks has posed important challenges (e.g., exploitation of the social relationships of mobile users and management of interference and resources towards a better performance of D2D communications). This article proposes a social-aware Radio Resource Allocation (RRA) optimization solution for D2D communications in 5G networks that considers partial Channel State Information (CSI). A selected-NM Maximum Distance Ratio (MDR) q-bit feedback scheme designed reduces feedback overhead, since each D2D receiver sends only q-bit feedback CSI of N cellular User Equipment (CUE) and M D2D pairs with the largest MDR metric. The RRA problem is solved by an Artificial Bee Colony (ABC) algorithm for the obtaining of number of D2D connections in each evolved NodeB (eNB) and maximization of the system throughput.

On energy efficient secure routing in multi-hop underlay D2D communications for IoT applications

In this paper, a physical layer security based secure routing problem in a multi-hop cognitive radio enabled device-to-device (CRD2D) communication, under the threat of multiple randomly distributed eavesdroppers (EVEs), is studied. Delivery of confidential packets between a given legitimate D2D transmitter–receiver pair is targeted with the aid of multiple intermediate legitimate D2D nodes that share spectrum of a predefined licensed∕primary user for their transmissions as unlicensed∕secondary users and operate on the principle of randomized-and-forward relaying. In view of the energy limitations of the D2D nodes engaged in IoT applications, the secure routing problem aims to maximize the secrecy energy efficiency (SEE) under the constraints of − (i) minimum secrecy rate (ii) minimum signal-to-interference plus noise ratio at any D2D receiver (iii) maximum primary user outage loss in presence of the D2D transmission (iv) maximum retransmission attempts by any D2D nodes. Based on our analysis, an optimal routing algorithm is proposed. Simulation results illustrate the dependence of SEE on various critical system parameters. Further, complexity analysis and implementation issues are also presented for the proposed routing algorithm.

Outage-Optimal and Suboptimal Power Control for D2D Communications in SWIPT Cellular Networks With Local CSI

In this letter, we consider a downlink cellular network where a cellular user (CU) not only decodes information but also harvests energy. By reusing the spectrum resource of the CU, a device-to-device (D2D) transmitter sends its own signals to a D2D receiver. In order to protect the CU from the interference due to the D2D signals, we propose transmit power control schemes for the D2D transmission without increasing the outage probability of the CU. This is possible since the CU’s information loss due to the D2D signals can be compensated by the CU’s energy harvesting gain from the D2D signals. For asymptotic performance analysis, we provide a lower bound on the D2D outage probability. The numerical results show that the proposed schemes outperform the conventional scheme.

Deep Learning for Selection Between RF and VLC Bands in Device-to-Device Communication

This letter focuses on the selection between radio frequency (RF) and visible light communications (VLC) bands for users exchanging data directly with each other via device-to-device (D2D) communication. We target to maximize the energy efficiency of D2D communication while the outage is minimized. Since the VLC channel can vary quickly due to the possible changes in irradiance and incidence angles, we aim to reach a quick band selection decision in a multi-user scenario based only on the knowledge of the received power and sum interference from all D2D transmitters at the individual D2D receivers. The proposed solution is based on a deep neural network making an initial band selection decision. Then, based on the DNN’s output, a fast heuristic algorithm is proposed to further improve the band selection decision. The results show that the proposal reaches a close-to-optimal performance and outperforms the existing solutions in complexity, outage ratio, and energy efficiency.

Outage performance analysis and resource allocation algorithm for energy harvesting D2D communication system

In this paper, we consider an energy harvesting device-to-device (D2D) communication system, where D2D transmitter can use mode A to directly communicate with D2D receiver or use mode B as a relay to assist cellular communication while communicating with D2D receiver by adopting non-orthogonal multiple access technology. Firstly, the outage probability expression in two modes is derived, and the communication mode is determined according to outage performance. Then, assuming that the full system information is available, the channel allocation and relay selection are completed by Kuhn–Munkres algorithm, and the offline power allocation of D2D users is realized by reinforcement learning. Next, the offline optimization results are taken as the training data set to train the neural network, and the optimal model of the transmission power is obtained. Considering the transmission power constraint, the online power allocation optimization algorithm is further proposed. Numerical results demonstrate the accuracy of derived outage probability, and the proposed resource allocation algorithm can improve the performance of hybrid system.

Deployment Model and Performance Analysis of Clustered D2D Caching Networks Under Cluster-Centric Caching Strategy

Device-to-Device (D2D) communication has become a promising candidate in future cellular networks to improve spectrum efficiency and energy efficiency, while reducing the latency. As the capacity of D2D user equipments (DUEs) increases, it makes DUEs caching possible, and it can offload traffic from macro base stations, perform computation-intensive and latency-critical tasks. In this paper, in-band communication is considered, and the Poisson cluster process is utilized to model and analyze the clustered D2D networks under cluster-centric caching strategy. Firstly, we use the Thomas cluster process to model cellular user equipments (CUEs) and DUEs, and give a deployment scheme of clustered D2D caching networks. Secondly, the aggregated interference of the typical D2D receiver is analyzed in the clustered D2D networks. Then the Laplace transform of the aggregated interference is analyzed, and the expressions of coverage probability, average achievable rate and cache hit probability of the typical D2D receiver are deduced. The simulation results show that we can adjust the path loss exponent, densities of DUEs and CUEs, transmitting power of CUEs, mean of simultaneously active transmitters in each cluster and Zipf exponent to improve the performance of clustered D2D caching networks.

Generalized Imperfect D2D Associations in Spectrum-Shared Cellular Networks Under Transmit Power and Interference Constraints

This paper studies imperfect underlay device-to-device (D2D) association in spectrum-shared cellular networks. It addresses important system and design interference constraints, processing load limitations and transmit power constraints at D2D terminals. The paper proposes decentralized schemes for D2D communication between D2D terminals when downlink channel resources can be reused in the D2D network. The D2D transmitters are characterized considering their processing load limitation and allocated transmit power constraints. Moreover, the downlink channels that can be reused in the D2D network are quantified while meeting interference constraints imposed by the primary cellular network. Two schemes to identify reusable channels, which vary in terms of their efficiency, communication overhead requirement and implementation complexity, are described. Moreover, two D2D association schemes, namely the simultaneous and sequential D2D associations, are proposed and both aim to concurrently maximize the desired link quality and minimize the effect of interference effect at D2D receivers. Generalized analytical results that are applicable for various imperfect association scenarios are presented. The findings are applicable for any D2D channel models and performance metrics. They provide insights into various imperfect underlay D2D association scenarios under the practical system and design constraints.

Robust Resource Allocation With Power Outage Guarantees for Energy Harvesting Aided Device-to-Device Communication

This paper studies the robust resource allocation to improve the robustness against the channel state information (CSI) uncertainties for energy harvesting (EH)-aided device-to-device (D2D) communication underlaying cellular network. In this network, EH-aided D2D transmitters can reuse the uplink cellular sub-channels to perform transmission to the desired D2D receivers. Assuming the link gains in the interference channels are uncertain, we formulate the robust resource allocation problem with a view to maximizing the sum-rate of the D2D links while guaranteeing the power outage Quality-of-Service (QoS) requirements and interference constraints. In doing so, both deterministic and statistical uncertainty model are adopted to specify the CSI uncertainties. This resulting robust problem is essentially non-convex and intractable in its original form. Therefore, we firstly utilize the worst-case approach and chance constraint approach to find its tractable and convex forms. Then, via employing the Lagrangian dual method, we derive the semi-closed expression for the power allocation and two rules for assigning sub-channels. Based on the theoretical results, a distributed subgradient-based iterative algorithm is developed to achieve the optimally robust resource allocation. Finally, an in-depth simulation is conducted to verify the effectiveness of the proposed algorithm and evaluate the effect of CSI uncertainties and power outage QoS requirement on the sum-rate of the D2D links.

Performance Analysis and Optimization of Cooperative Full-Duplex D2D Communication Underlaying Cellular Networks

This paper investigates the cooperative full-duplex device-to-device (D2D) communication underlaying a cellular network, where the cellular user (CU) acts as a full-duplex relay to assist the D2D communication. To simultaneously support D2D relaying and uplink transmission, superposition coding and successive interference cancellation are adopted at the CU and the D2D receiver, respectively. The achievable rate region and joint outage probability are derived to characterize the performance of the considered system. In consideration of the fairness between the cellular uplink and the D2D link, an optimal power allocation scheme is proposed to maximize the minimum achievable rate of them. Besides, by analyzing the upper bound of the joint outage probability, we study a suboptimal power allocation to improve the outage performance. The simulation results confirm the theoretical analysis and the advantages of the proposed power allocation schemes.

Exploiting NOMA in D2D assisted full-duplex cooperative relaying

This paper proposes a device-to-device (D2D) enabling cellular full-duplex (FD) cooperative (DFC) protocol using non-orthogonal multiple access (NOMA) called DFC-NOMA, where an FD relay acting D2D transmitter assists in relaying a NOMA far user’s signal and transmits a D2D receiver’s signal simultaneously. The ergodic capacity, outage probability, and diversity order of DFC-NOMA are theoretically investigated under the assumption of both perfect and imperfect interference cancellation. The theoretical analysis is then validated by simulations. Both analysis and simulation results demonstrate the performance gain of DFC-NOMA over conventional FD cooperative NOMA and existing D2D aided FD NOMA.

Quality of Service Provisioning for D2D Users in Heterogeneous Networks

This paper investigates power allocation for D2D communications in a Heterogeneous Network (HetNet) which includes a macro cell and pico cells, whereas femto cells are distributed inside. The objective is to minimize the total power consumption of D2D transmitter while satisfying a set of Quality of Service in D2D receivers and cellular users communication interference. To this end, we first obtain expression for the formula of signal to interference plus noise ratio (SINR) and spectral efficiency of each D2D receiver. Then, an optimization problem is formulated to minimize the total transmit power of D2D transmitters subject to QoS constraints. It is shown that this optimization problem is linear programming and it can be solved in polynomial time with standard tools. In addition, the maximization value of D2D pair transmission rates are determined with fixed cellular users parameters.

Weighted Sum Energy Efficiency Maximization of Device-to-Device groups underlaying NOMA cellular network

The problem of Weighted Sum Energy Efficiency (WSEE) Maximization of Device-to-Device (D2D) groups with underlaid Non-Orthogonal Multiple Access (NOMA) cellular network is investigated in this paper. In the novel network model, transmitters in each of the D2D groups will be able to communicate with multiple D2D receivers in the same spectral sub-band via NOMA protocol. Similarly, Base Station (BS) also communicates with multiple Cellular Users (CUs) via NOMA strategy. Power allocation for this hybrid network is presented in this paper. Optimization problem is formulated as WSEE Maximization of the D2D groups. This framework is suitable for energy-crunch devices, where the nodes can have different energy efficiency requirements. Further, to meet Quality of Service (QoS), rate constraints are imposed on all the receivers in the network. The optimization problem is challenging because of its non-convex sum-of-ratios form. So, it is first converted into an equivalent convex form. Subsequently, a successive convex approximation based algorithm is used to obtain optimal power distribution. The proposed power allocation algorithm is shown to be convergent and the simulation results closely match with the optimal values at all Signal-to-Noise Ratio (SNR) values.

Joint Mode Selection and Resource Allocation for D2D-Enabled NOMA Cellular Networks

The 5G cellular network employs non-orthogonal multiple access (NOMA) to enhance network connectivity and capacity, and device-to-device (D2D) communications to improve spectrum efficiency. However, the underlay D2D communications may destroy the execution condition for the successive interference cancellation (SIC) decoding of NOMA cellular networks by introducing the extra interference, which degrades the cellular transmission reliability. Thus, we develop the interlay mode as a special D2D mode for NOMA system, which enables the power domain multiplexing of the D2D pair and cellular users to eliminate the strong interference between them by the SIC decoding. When D2D pair conducts the selection between the interlay mode and underlay mode, the SIC decoding constraint should be satisfied at both D2D receiver and NOMA base station. In order to maximize the system sum rate while meeting the SIC decoding constraint, we propose a joint D2D mode selection and resource allocation scheme with interlay mode, which can be formulated as a combinatorial optimization problem. To tackle the combinatorial nature of mode selection and spectrum assignment, we first prove that the original problem can be reformulated as a maximum weight clique problem, and then propose a graph-based algorithm by applying branch-and-bound method to obtain its optimal solution. Finally, simulation results are provided to demonstrate that the interlay mode along with the proposed algorithms can coordinate D2D communications and NOMA cellular network to significantly improve the system sum rate and the D2D access rate.

Multiple device-to-device users underlaying downlink cellular networks with superposition coding

Device-to-Device (D2D) communications has been proposed to provide high data rate service via direct transmissions between devices. Cooperation between the cellular user (CU) and the D2D user can be achieved using superposition coding, where the D2D transmitter (DT) allocates some of its transmission power to forward the CU’s traffic, and transmits to its own D2D receiver (DR) with the remaining power. The sum rate of the cellular and D2D networks in existing schemes are limited by allowing only a single pair of D2D users underlaying the cellular network. In this paper, we propose several new spectrum access policies involving multiple D2D pairs. Despite the additional interference, it is shown that both the CU and the individual D2D users’ achievable rates can be improved simultaneously by adjusting the power allocation factor in the superposition coding, resulting in a significant gain in the sum rate when the number of D2D pairs are below a threshold. This threshold is quantified using second order approximations for the average achievable rates for both the CU and the individual D2D users for different policies.

Performance Analysis and Resource Allocation for Cooperative D2D Communication in Cellular Networks With Multiple D2D Pairs

In this letter, we investigate cooperative device-to-device (D2D) communication in an uplink cellular network, where D2D users act as relays for cellular users. We derive the outage probability of a cellular user and the average achievable rate from a D2D transmitter to a D2D receiver in analytic form. We obtain optimal spectrum and power allocation to maximize the total average achievable rate under the outage probability constraint. The validity of the analysis is verified by computer simulations.