Showing papers by "Amitava Ghosh published in 2017"

Performance of Dynamic and Static TDD in Self-backhauled mmWave Cellular Networks

Abstract: Initial deployments of millimeter wave (mmWave) cellular networks are likely to be enabled with self-backhauling. In this work, we propose a random spatial model to analyze uplink (UL) and downlink (DL) SINR distribution and mean rates corresponding to different access-backhaul and UL-DL resource allocation schemes in a self-backhauled mmWave cellular network with Poisson point process (PPP) deployment of users and base stations. In particular, we focus on heuristic implementations of static and dynamic time division duplexing (TDD) for access links with synchronized or unsynchronized access-backhaul (SAB or UAB) time splits. We propose PPP approximations to characterize the distribution of the new types of interference encountered with dynamic TDD and UAB. These schemes offer better resource utilization than static TDD and SAB, however potentially higher interference makes their choice non-trivial and the offered gains sensitive to different network parameters, including UL/DL traffic asymmetry, user load per BS or number of slave BSs per master BS. One can harness notable gains from UAB and/or dynamic TDD only if backhaul links are designed to have much larger throughput than the access links.

LTE-M Evolution Towards 5G Massive MTC

Abstract: Massive machine type communication (mMTC) has been identified as an important use case for 5G New Radio wireless technology In 4G Long-Term Evolution (LTE), 3GPP has previously introduced LTE-M for low-power, wide-area networks supporting the Internet of Things Rel-13 specifications for LTE-M were completed in 2016 Rel-14 enhancements were completed in 2017 while Rel-15 enhancements are ongoing and expected to be completed in 2018 In this paper, we provide an overview of LTE-M and describe its evolution in subsequent releases The features of the technology that have specifically been designed for mMTC are discussed In addition, we present evaluations of LTE-M against 5G performance targets and show that mMTC requirements can be satisfied by LTE-M To meet the 5G mMTC requirements, 3-dB power spectral density boosting is used in the downlink In addition, for some requirements, 4 receive antennas at the eNB are required instead of the more typical 2 receive antennas Thus, LTE-M will comprise an important component of 5G New Radio technology

Millimeter Wave Communications for Future Mobile Networks

Abstract: Millimeter wave (mmWave) communications have recently attracted large research interest, since the huge available bandwidth can potentially lead to rates of multiple Gbps (gigabit per second) per user. Though mmWave can be readily used in stationary scenarios such as indoor hotspots or backhaul, it is challenging to use mmWave in mobile networks, where the transmitting/receiving nodes may be moving, channels may have a complicated structure, and the coordination among multiple nodes is difficult. To fully exploit the high potential rates of mmWave in mobile networks, lots of technical problems must be addressed. This paper presents a comprehensive survey of mmWave communications for future mobile networks (5G and beyond). We first summarize the recent channel measurement campaigns and modeling results. Then, we discuss in detail recent progresses in multiple input multiple output (MIMO) transceiver design for mmWave communications. After that, we provide an overview of the solution for multiple access and backhauling, followed by analysis of coverage and connectivity. Finally, the progresses in the standardization and deployment of mmWave for mobile networks are discussed.

Millimeter Wave Communications for Future Mobile Networks (Guest Editorial), Part I

Abstract: For the potential of providing rates of multiple Giga-bps in a single channel, millimeter wave (mmWave) communications have recently attracted substantial research interest. While mmWave technology is already being used in stationary scenarios such as indoor hotspots or backhaul, it is challenging to use mmWave frequencies in mobile networks, where transmitting/receiving nodes may be moving, channels may have a complicated structure, and the coordination among multiple nodes is difficult. To fully exploit the high potential rates of mmWave in mobile networks, many significant technical challenges must be tackled. The main objective of this IEEE JSAC Special Issue on “ Millimeter wave communications for future mobile networks ” is to collect the most recent technical advances in mmWave for future mobile networks. The response from the community to the call has been overwhelming. We received 96 submissions with a call period short than 4 months. Many of the submissions are from the most well known research groups in the field. After a strict review process, we decided to accept 38 papers, which will be published in two issues. The papers were selected based on the technical relevance and merits. Unfortunately, due to space limitations, a number of interesting papers were not selected, despite the merits that they had. We sincerely hope those papers can find other publishing venues.

Performance Analysis of Voice over LTE Using Low-Complexity eMTC Devices

Abstract: The Internet of Things (IoT) is expected to reach a massive scale in the next few years and LTE has introduced a feature in Rel-13 called eMTC to support wide-area connectivity for IoT devices. One important trend for IoT is the integration of voice capability into the devices. However, low-cost, low-complexity IoT User Equipment (UE) typically supports only half-duplex communication and low data rates. In this paper, we compare the performance and coverage of low-complexity eMTC UE with legacy non-eMTC UE for delay-sensitive Voice over LTE (VoLTE) service. It is shown that eMTC UE can provide similar coverage to non-eMTC UE using the same delay and block error rate requirements. If the delay budget or quality of service can be relaxed for eMTC, then eMTC can provide slightly better VoLTE coverage. This allows service operators to support voice capability for IoT devices using existing infrastructure footprint.

Investigation of Non-Orthogonal Multiple Access Techniques for Future Cellular Networks

Abstract: There is an expected explosion in the number of users which will be connected to future wireless networks with the continued expansion of the Internet of Things. New technologies are needed in order to keep up with this connectivity demand. Non-orthogonal multiple access (NOMA) is one technology which seeks to improve spectral efficiency and allow for more connected users. NOMA seeks to overload resources in order to allow more users to access the same time and frequency resource blocks. There have been various proposals on how to realize NOMA in the network, including power domain non-orthogonal multiple access (PD-NOMA), interleave division multiple access(IDMA), and sparse code multiple access (SCMA). This paper investigates these three proposals and simulates them in the uplink setting in order to analyze their performance and compare them. Advantages and disadvantages for each technique are discussed with an emphasis on practical considerations.