scholarly journals Experimental Interference Robustness Evaluation of IEEE 802.15.4-2015 OQPSK-DSSS and SUN-OFDM Physical Layers for Industrial Communications

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1045 ◽  
Author(s):  
Pere Tuset-Peiró ◽  
Francisco Vázquez-Gallego ◽  
Jonathan Muñoz ◽  
Thomas Watteyne ◽  
Jesus Alonso-Zarate ◽  
...  
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Ieee 802.15.4 ◽  
Physical Layer ◽  
Direct Sequence Spread Spectrum ◽  
Spectrum Efficiency ◽  
Delivery Ratio ◽  
The Sun ◽  
Physical Layers ◽  
The Impact ◽  
Industrial Communications

In this paper, we experimentally evaluate and compare the robustness against interference of the OQPSK-DSSS (Offset Quadrature Phase Shift Keying-Direct Sequence Spread Spectrum) and the SUN-OFDM (Smart Utility Network-Orthogonal Frequency Division Multiplexing) physical layers, as defined in the IEEE 802.15.4-2015 standard. The objective of this study is to provide a comprehensive analysis of the impact that different levels of interference produce on these modulations, in terms of the resulting PDR (Packet Delivery Ratio) and depending on the length of the packet being transmitted. The results show that the SUN-OFDM physical layer provides significant benefits compared to the ubiquitous OQPSK-DSSS in terms of interference robustness, regardless of the interference type and the packet length. Overall, this demonstrates the suitability of choosing the SUN-OFDM physical layer when deploying low-power wireless networks in industrial scenarios, especially taking into consideration the possibility of trading-off robustness and spectrum efficiency depending on the application requirements.

scholarly journals Sparse code multiple access on the generalized frequency division multiplexing

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Guilherme P. Aquino ◽  
Luciano L. Mendes
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Access ◽  
Physical Layer ◽  
Spectrum Efficiency ◽  
Sparse Code ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Time Frequency ◽  
Performance Loss

Abstract Recent advances in the communication systems culminated in a new class of multiple access schemes, named non-orthogonal multiple access (NOMA), where the main goal is to increase the spectrum efficiency by overlapping data from different users in a single time-frequency resource used by the physical layer. NOMA receivers can resolve the interference among data symbols from different users, increasing the overall system spectrum efficiency without introducing symbol error rate (SER) performance loss, which makes this class of multiple access techniques interesting for future mobile communication systems. This paper analyzes one promising NOMA technique, called sparse code multiple access (SCMA), where C users can share U<C time-frequency resources from the physical layer. Initially, the SCMA and orthogonal frequency division multiplexing (OFDM) integration is considered, defining a benchmark for the overall SER performance for the multiple access technique. Furthermore, this paper proposes the SCMA and generalized frequency division multiplexing (GFDM) integration. Since GFDM is a highly flexible non-orthogonal waveform that can mimic several other waveforms as corner cases, it is an interesting candidate for future wireless communication systems. This paper proposes two approaches for combining SCMA and GFDM. The first one combines a soft equalizer, called block expectation propagation (BEP), and a multi-user detection (MUD) scheme based on the sum-product algorithm (SPA). This approach achieves the best SER performance, but with the significant increment of the complexity at the receiver. In the second approach, BEP is integrated with a simplified MUD, which is an original contribution of this paper, aiming for reducing the receiver’s complexity at the cost of SER performance loss. The solutions proposed in this paper show that SCMA-GFDM can be an interesting solution for future mobile networks.

scholarly journals Determinism through Modulation Diversity: Can Combining Multiple IEEE 802.15.4-2015 SUN Modulations Improve Communication Reliability?

2020 ◽  
Author(s):  
Pere Tuset-Peiró ◽  
Ferran Adelantado ◽  
Xavier Vilajosana ◽  
Ruan Delgado Gomes
Keyword(s):  
Ieee 802.15.4 ◽  
Industrial Applications ◽  
Wireless Channel ◽  
Delivery Ratio ◽  
The Sun ◽  
Power Devices ◽  
Trade Data ◽  
Packet Delivery ◽  
Communication Reliability ◽  
Modulation Diversity

The IEEE 802.15.4-2015 standard includes the SUN (Smart Utility Networks) modulations, i.e., SUN-FSK, SUN-OQPSK and SUN-OFDM, which provide long range communications and allow to trade data rate, occupied bandwidth and reliability. However, given the constraints of low-power devices and the challenges of the wireless channel, communication reliability cannot still meet the PDR (Packet Delivery Ratio) requirements of industrial applications, i.e., PDR&gt;99%. Hence, in this paper we evaluate the benefits of improving communication reliability by combining packet transmissions with modulation diversity using multiple IEEE 802.15.4g SUN modulations. The results derived from a real-world deployment show that going from 1 to 3 packet transmissions with the same SUN modulation can increase PDR from 85.0/84.6/71.3% to 94.2/94.1/86.0% using SUN-FSK, SUN-OQPSK and SUN-OFDM, respectively. Combining the same number of packet transmissions with modulation diversity allows to further increase the average PDR to 97.1%, indicating its potential as a tool to help meeting the reliability requirements of industrial applications.

scholarly journals Impact of using CSS PHY and RTS/CTS Combined with Frame Concatenation in the IEEE 802.15.4 Non-beacon Enabled Mode Performance

2020 ◽  
Author(s):  
Norberto Barroca ◽  
Luís M. Borges ◽  
Fernando José Velez ◽  
Periklis Chatzimisios
Keyword(s):  
Spread Spectrum ◽  
Ieee 802.15.4 ◽  
Direct Sequence Spread Spectrum ◽  
Bandwidth Efficiency ◽  
Direct Sequence ◽  
Maximum Throughput ◽  
Physical Layers ◽  
Delay Performance ◽  
Minimum Delay ◽  
Throughput And Delay

This paper studies the performance improvement for the nonbeacon-enabled mode of IEEE 802.15.4 originated by the inclusion of the Request-To-Send/Clear-To-Send (RTS/CTS) handshake mechanism combined with frame concatenation. Under IEEE 802.15.4 employing RTS/CTS, the backoff procedure is not repeated for each data frame sent but only for each RTS/CTS set. The throughput and delay performance are mathematically derived for both the Chirp Spread Spectrum and Direct Sequence Spread Spectrum Physical layers for the 2.4 GHz band. The results show that the utilization of RTS/CTS significantly enhances the performance of IEEE 802.15.4 in terms of maximum throughput, minimum delay and bandwidth efficiency.

The Homeland, Imprisoned and Illegal: The Impact of Marginalisation on Views of the Homeland in Kanafānī's and Khalīfa's Work

2019 ◽  
Vol 13 (1) ◽  
pp. 1-18
Author(s):  
Jedidiah Anderson
Keyword(s):  
Affect Theory ◽  
The Sun ◽  
Minor Literature ◽  
War Machine ◽  
Ghassan Kanafani ◽  
The Impact

This paper deals with the concept of Al-Waṭan, or ‘the homeland’, in Arabic in The Shell (Al-Qawqʿa) by Muṣṭafā Khalifa and Men in the Sun (Rijāl fīsh-Shams) by Ghassān Kanafānī. Analysis of how alienation from this concept has affected both Khalifa's and Kanafānī's characters is carried out through the lenses of Deleuze and Guattari's theories of rhizomatic associations and minor literature, as well as through the lens of affect theory. The paper also examines parallels between definitions of Al-Waṭan/the homeland in Ibn Manẓūr's classical dictionary Lisān al-ʿArab and Deleuze and Guattari's concepts of the war machine and the apparatus of capture.

scholarly journals Duty Cycle Control Method Considering Buffer Occupancy for IEEE 802.15.4-Compliant Heterogeneous Wireless Sensor Network

2021 ◽  
Vol 11 (4) ◽  
pp. 1362
Author(s):  
Kohei Tomita ◽  
Nobuyoshi Komuro
Keyword(s):  
Duty Cycle ◽  
Ieee 802.15.4 ◽  
Control Method ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Delivery Ratio ◽  
Buffer Occupancy ◽  
Heterogeneous Wireless Sensor Networks ◽  
Heterogeneous Wireless Sensor Network ◽  
Analytical Expressions

This paper proposes a Duty-Cycle (DC) control method in order to improve the Packet Delivery Ratio (PDR) for IEEE 802.15.4-compliant heterogeneous Wireless Sensor Networks (WSNs). The proposed method controls the DC so that the buffer occupancy of sensor nodes is less than 1 and assigns DC to each sub-network (sub-network means a network consisting of a router node and its subordinate nodes). In order to use the appropriate DC of each sub-network to obtain the high PDR, this paper gives analytical expressions of the buffer occupancy. The simulation results show that the proposed method achieves a reasonable delay and energy consumption while maintaining high PDR.

Mobility aware of WDM-based CMO OFDM communication system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Saad M. Hardan ◽  
Ayad A. Abdulkafi ◽  
Saadi Hamad Thalij ◽  
Sherine S. Jumaah
Keyword(s):  
Wavelength Division Multiplexing ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Light Emitting Diode ◽  
Access Point ◽  
Mobile Users ◽  
Visible Light Communications ◽  
Optical Wireless Communications ◽  
High Data ◽  
The Impact

Abstract The continued increase in several mobile applications forces to replace existing limited spectrum indoor radio frequency wireless connections with high-speed ones. Visible light communications (VLC) technology has gained prominence in the development of high data rate transmission for fifth-generation networks. In optical wireless communications, light-emitting diode (LED) transmitters are used in applications that desire mobility as LED divergence enables larger coverage. Since each VLC access point covers a small area, handovers of mobile users are inevitable. Wavelength division multiplexing (WDM) can be used in VLC systems to tackle the above issue and to meet the increasing demand for indoor connectivity with high bit rates. In this paper, a new system architecture for WDM with coded modulated optical in orthogonal frequency division multiplexing (OFDM) VLC system in conjunction with red, green, blue, and yellow (RGBY) LEDs is proposed to reduce the impact of random receiver orientation of indoor mobile users over VLC downlink channels and improves the system’s bit-error-rate (BER) performance. Simulation results show that the proposed method is not affected by the user’s mobility and hence it performs better than other approaches, in terms of BER for all scenarios and at all positions. This study reveals that using WDM-OFDM-VLC with RGBY LEDs to construct a VLC system is very promising.

scholarly journals Joint UAV channel modeling and power control for 5G IoT networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Xiuhua Fu ◽  
Tian Ding ◽  
Rongqun Peng ◽  
Cong Liu ◽  
Mohamed Cheriet
Keyword(s):  
Energy Efficiency ◽  
Power Control ◽  
Channel Model ◽  
Path Loss ◽  
Channel Modeling ◽  
Signal Propagation ◽  
Spectrum Efficiency ◽  
Propagation Path ◽  
Control Factor ◽  
The Impact

AbstractThis paper studies the communication problem between UAVs and cellular base stations in a 5G IoT scenario where multiple UAVs work together. We are dedicated to the uplink channel modeling and the performance analysis of the uplink transmission. In the channel model, we consider the impact of 3D distance and multi-UAVs reflection on wireless signal propagation. The 3D distance is used to calculate the path loss, which can better reflect the actual path loss. The power control factor is used to adjust the UAV's uplink transmit power to compensate for different propagation path losses, so as to achieve precise power control. This paper proposes a binary exponential power control algorithm suitable for 5G networked UAV transmitters and presents the entire power control process including the open-loop phase and the closed-loop phase. The effects of power control factors on coverage probability, spectrum efficiency and energy efficiency under different 3D distances are simulated and analyzed. The results show that the optimal power control factor can be found from the point of view of energy efficiency.

Optical OFDM for Downstream Transmission in Long-Reach PON

2014 ◽  
Vol 631-632 ◽  
pp. 860-863 ◽  
Author(s):  
Xiao Xue Gong ◽  
Hui Li ◽  
Peng Chao Han ◽  
Yu Fang Zhou
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Direct Detection ◽  
Dispersion Compensation ◽  
Chromatic Dispersion ◽  
Optical Network ◽  
Digital Signal ◽  
Least Square ◽  
Passive Optical Network ◽  
Spectrum Efficiency ◽  
Flexible Resource

Orthogonal Frequency Division Multiplexing (OFDM) has gained great attention in the next generation Long-Reach Passive Optical Network (LR-PON) due to its high spectrum efficiency, flexible resource allocation and natural compatibility with Digital Signal Processing (DSP)-based implementation. In this paper, we propose and demonstrate a 40Gbit/s direct-detection long reach OFDM-PON system for downstream transmission over 100km standard signal mode fiber (SSMF). By using a simple Least Square (LS) method for the channel estimation, our proposed system achieves high bit rate without the need for chromatic dispersion compensation.

scholarly journals Evaluation of PLC Channel Capacity and ABER Performances for OFDM-Based Two-Hop Relaying Transmission

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Sana Ezzine ◽  
Fatma Abdelkefi ◽  
Jean Pierre Cances ◽  
Vahid Meghdadi ◽  
Ammar Bouallégue
Keyword(s):  
Channel Capacity ◽  
Orthogonal Frequency Division Multiplexing ◽  
Low Cost ◽  
Relay Node ◽  
Destination Node ◽  
Direct Link ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Maximum Ratio Combining ◽  
The Impact

Powerline network is recognized as a favorable infrastructure for Smart Grid to transmit information in the network thanks to its broad coverage and low cost deployment. The existing works are trying to improve and adapt transmission techniques to reduce Powerline Communication (PLC) channel attenuation and exploit the limited bandwidth to support high data rate over long distances. Two-hop relaying BroadBand PLC (BB-PLC) system, in which Orthogonal Frequency Division Multiplexing (OFDM) is used, is considered in this paper. We derive and compare the PLC channel capacity and the end-to-end Average BER (ABER) for OFDM-based direct link (DL) BB-PLC system and for OFDM-based two-hop relaying BB-PLC system for Amplify and Forward (AF) and Decode and Forward (DF) protocols. We analyze the improvements when we consider the direct link in a cooperative communication when the relay node only transmits the correctly decoded signal. Maximum ratio combining is employed at the destination node to detect the transmitted signal. In addition, in this paper, we highlight the impact of the relay location on the channel capacity and ABER for AF and DF transmission protocols. Moreover, an efficient use of the direct link was also investigated in this paper.

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