Sandeep Joshi

Bio: Sandeep Joshi is an academic researcher from Birla Institute of Technology and Science. The author has contributed to research in topics: Fading & Nakagami distribution. The author has an hindex of 6, co-authored 18 publications receiving 105 citations. Previous affiliations of Sandeep Joshi include Indian Institute of Technology Delhi & Shiv Nadar University.

Coverage and Interference in D2D Networks With Poisson Cluster Process

Abstract: In this letter, we present an analytical framework for the coverage probability analysis in a device-to-device (D2D) network with the location of devices modeled as a Poisson cluster process. We consider Nakagami- $m$ fading between the D2D communication links, which provides a more realistic scenario for the performance analysis. We assume a standard singular path loss model and use stochastic geometry as a tool for the interference and coverage probability analysis. Furthermore, we derive a closed form approximate expression and a bound on the coverage probability, and also include the interference-limited case. Numerical results corroborate our analysis.

Analysis of dedicated and shared device-to-device communication in cellular networks over Nakagami-m fading channels

Abstract: Device-to-device (D2D) communication, unlike conventional cellular communication, is described as the direct communication between devices bypassing the network infrastructure. This mode of direct communication, due to its advantages, is being proposed as an integral part of the next generation cellular networks with the additional interference between the users being a challenge. In this study, the authors develop an analytical framework for a D2D-enabled downlink cellular network with Nakagami- m fading between the D2D communication links. The authors derive tractable expressions for the coverage probability of D2D links and cellular users, considering different propagation conditions experienced by D2D and cellular links. Using stochastic geometry, the authors provide the coverage probability analysis for the dedicated network, having orthogonal frequency resource allocation, and for the shared network, where the frequency resources are reused. Furthermore, the authors extend the coverage probability analysis to include interference-limited dedicated and shared networks. Numerical results corroborate their analysis. The authors also derive the expressions for ergodic spectral efficiency of D2D links for both dedicated and shared networks. The results obtained are helpful in understanding the system behaviour and show the dependence of network performance on the system parameters.

Smart Grid Network With D2D Communication and Coherent PLC: Error Analysis

Abstract: In this paper, we consider a hybrid smart grid communication network consisting of power line communication (PLC) at the transmitter side and the device-to-device (D2D) cellular communication on the receiver side which provides last mile connectivity. The PLC channel is assumed to experience Rayleigh fading and is corrupted by impulsive noise, and the D2D communication being a short range communication system, is assumed to experience Nakagami- $m$ fading with additive Gaussian noise. We propose a maximal-ratio combining (MRC) receiver for the considered hybrid smart grid communication system employing binary phase shift keying (BPSK) modulation at the transmitter and derive a closed-form symbol error probability (SEP) expression for the proposed receiver. The interference between the D2D links is assumed to be negligible for the tractability of the error probability analysis. Numerical results demonstrate the optimality of operating the D2D links at lower signal-to-noise ratio (SNR) values to overcome the effect of the impulsive PLC channel by utilizing diversity branches.

Coverage Probability Analysis in a Device-to-Device Network: Interference Functional and Laplace Transform Based Approach

Abstract: In this letter, we provide an interference functional and Laplace transform based analysis using stochastic geometry to evaluate the expectation over the interference, which is further used to derive the coverage probability expressions for device-to-device (D2D) links. We assume a more practically relevant Nakagami- $ {m}$ fading distribution to model fading between the D2D communication links considering interference from both D2D and cellular links. We also derive a bound on the coverage probability, which simplifies the coverage computations at higher values of the fading parameter. Furthermore, the numerical results corroborate the presented coverage analysis.

Cooperative Device-to-Device Relaying Network with Power Line Communications

Abstract: Cooperative device-to-device communication with non- orthogonal multiple access (NOMA) employing additional power line communication technology is an effective way to increase the coverage and spectral efficiency of the next generation hybrid networks. In this paper, we present the outage analysis of a cooperative network with NOMA and decode-and-forward relaying assuming a direct link between the base station and the users. We consider a relaying network consisting of a wireless link for the strong user and the weak user having both wireless and a wired link which is assumed as a power line link. The wireless links are subjected to Nakagami-m fading and the power line link experiences Rayleigh fading. The outage probability expressions for both the strong and the weak users are derived assuming power division NOMA and perfect successive interference cancellation at the receivers. We also derive the optimal value of the NOMA power allocation coefficient minimizing the outage probability at the strong user and obtain the range of the power allocation coefficient between the power line and the wireless link at the weak user. Furthermore, numerical results validate the derived analytical results.

Non-Orthogonal Multiple Access (NOMA) for cellular future radio access

Abstract: Radio access technologies for cellular mobile communications are typically characterized by multiple access schemes, e.g., frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), and OFDMA. In the 4th generation (4G) mobile communication systems such as Long-Term Evolution (LTE) (Au et al., Uplink contention based SCMA for 5G radio access. Globecom Workshops (GC Wkshps), 2014. doi:10.1109/GLOCOMW.2014.7063547) and LTE-Advanced (Baracca et al., IEEE Trans. Commun., 2011. doi:10.1109/TCOMM.2011.121410.090252; Barry et al., Digital Communication, Kluwer, Dordrecht, 2004), standardized by the 3rd Generation Partnership Project (3GPP), orthogonal multiple access based on OFDMA or single carrier (SC)-FDMA is adopted. Orthogonal multiple access was a reasonable choice for achieving good system-level throughput performance with simple single-user detection. However, considering the trend in 5G, achieving significant gains in capacity and system throughput performance is a high priority requirement in view of the recent exponential increase in the volume of mobile traffic. In addition the proposed system should be able to support enhanced delay-sensitive high-volume services such as video streaming and cloud computing. Another high-level target of 5G is reduced cost, higher energy efficiency and robustness against emergencies.

Interference Management in 5G and Beyond Network: Requirements, Challenges and Future Directions

Abstract: In the modern technological world, wireless communication has taken a massive leap from the conventional communication system to a new radio communication network. The novel concept of Fifth Generation (5G) cellular networks brings a combination of a diversified set of devices and machines with great improvement in a unique way compared to previous technologies. To broaden the user’s experience, 5G technology provides the opportunity to meet the people’s potential necessities for efficient communication. Specifically, researchers have designed a network of small cells with unfamiliar technologies that have never been introduced before. The new network design is an amalgamation of various schemes such as Heterogeneous Network (HetNet), Device-to-Device (D2D) communication, Internet of Things (IoT), Relay Node (RN), Beamforming, Massive Multiple Input Multiple Output (M-MIMO), millimeter-wave (mm-wave), and so on. Also, enhancement in predecessor’s techniques is required so that new radio is compatible with a traditional network. However, the disparate technological models’ design and concurrent practice have created an unacceptable intervention in each other’s signals. These vulnerable interferences have significantly degraded the overall network performance. This review article scrutinizes the issues of interferences observed and studied in different structures and techniques of the 5G and beyond network. The study focuses on the various interference effect in HetNet, RN, D2D, and IoT. Furthermore, as an in-depth literature review, we discuss various types of interferences related to each method by studying the state-of-the-art relevant research in the literature. To provide new insight into interference issue management for the next-generation network, we address and explore various relevant topics in each section that help make the system more robust. Overall, this review article’s goal is to guide all the stakeholders, including students, operators, engineers, and researchers, aiming to explore this promising research theme, comprehend interferences and their types, and related techniques to mitigate them. We also state methodologies proposed by the $3^{\mathrm {rd}}$ Generation Partnership Project (3GPP) and present the promising and feasible research directions toward this challenging topic for the realization of 5G and beyond network.

A Distance-Based Mode Selection Scheme for D2D-Enabled Networks With Mobility

Abstract: In this paper, a new mode selection scheme for device-to-device (D2D)-enabled cellular communications with mobility is proposed and evaluated. The new scheme is based on an average threshold D2D distance between two given users to trigger the D2D mode. Besides, a tractable analytical framework considering relative movement for mode selection in moving D2D scenarios is presented. Under the proposed model, the expressions of the average threshold D2D distance, the probability of using D2D mode, the successful transmission probability, and the minimum D2D mode residence time are derived, which are the key parameters to evaluate the performance of D2D-enabled networks. Monte Carlo simulations are conducted to confirm the analytical results and the advantages of the proposed scheme over previously proposed ones. They show also the importance of studying the dynamic performance of the system in terms of user mobility as articulated in the calculated minimum D2D residence time.

Coverage and Interference in D2D Networks With Poisson Cluster Process

Abstract: In this letter, we present an analytical framework for the coverage probability analysis in a device-to-device (D2D) network with the location of devices modeled as a Poisson cluster process. We consider Nakagami- $m$ fading between the D2D communication links, which provides a more realistic scenario for the performance analysis. We assume a standard singular path loss model and use stochastic geometry as a tool for the interference and coverage probability analysis. Furthermore, we derive a closed form approximate expression and a bound on the coverage probability, and also include the interference-limited case. Numerical results corroborate our analysis.

A Survey on Application of Non-Orthogonal Multiple Access to Different Wireless Networks

Abstract: The fifth generation (5G) wireless systems are anticipated to meet unprecedented capacity and latency requirements. In order to resolve these challenges in 5G, non-orthogonal multiple access (NOMA) is considered as a promising technique due to its ability to enhance spectrum efficiency and user access. As opposed to conventional orthogonal multiple access (OMA) which relies on orthogonal resource sharing, NOMA has a potential of supporting a higher number of users by multiplexing different users in the same resource in a non-orthogonal manner. With advanced receiver techniques, such as successive interference cancellation (SIC), the intra-user interference can be minimized at the NOMA receiver. To date, there are comprehensive surveys on NOMA, which describe the integration of NOMA with different communication technologies and discuss different NOMA classifications. However, the existing literature is scarce in reviewing state-of-the-art applications of NOMA from the perspective of its application to cellular networks (CNs), device-to-device (D2D) communications, and wireless sensor networks (WSNs). Therefore, the purpose of this survey is to fill this gap in knowledge. Specifically, NOMA with its underlying concepts are elaborated in detail. In addition, detailed system model of different NOMA-based wireless networks is presented. Furthermore, irrespective of the underlying spatial topology of the considered NOMA-based wireless network, general analytical expressions are presented to characterize the network performance. Finally, some challenges related to NOMA design are highlighted and potential research directions are pointed out to address these issues.