scholarly journals TDS-OFDM based Digital Television Terrestrial Multimedia Broadcasting Standards

2020 ◽  
Vol 2020 (6) ◽  
pp. 38-49
Author(s):  
Jian Song ◽  
Chao Zhang ◽  
Jintao Wang ◽  
Yonglin Xue ◽  
Changyong Pan ◽  
...  
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
First Generation ◽  
Spectrum Efficiency ◽  
Frame Structure ◽  
Single Frequency ◽  
Digital Television ◽  
Modulation Scheme ◽  
High Definition ◽  
Wide Range ◽  
Digital Terrestrial Television

As the most popularly utilized broadcasting network, digital terrestrial television broadcasting (DTTB) can provide multimedia information coverage for the broad audience in a very efficient way because of its characteristic of wide-range coverage and mobile reception ability. After promulgating the first generation DTTB standard, digital terrestrial/television multimedia broadcasting (DTMB), in 2006, China began to research and develop the next generation DTTB standard, namely DTMB-advanced (DTMB-A), aiming to support higher spectrum efficiency and further improve transmission reliability. In 2019, DTMB-A was accepted by ITU as the second generation international DTTB standard (as System C). Similar to DTMB, time-domain synchronous - orthogonal frequency division multiplexing (TDS-OFDM) based multi-carrier modulation scheme is adopted by DTMB-A. Thanks to the more flexible frame structure, advanced error correction coding and improved constellation mapping, DTMB-A offers 30% higher transmission capacity than DTMB under the same transmission conditions. Thus, DTMB-A can support both fixed and mobile reception more efficiently, and provide users with higher quality services such as ultra-high definition television (UHDTV). This paper first gives details of key technologies at the transmitter of DTMB/DTMB-A and introduce core algorithms at the receiver. Both laboratory test and field trial results will then be provided and analyzed, especially for the application of 4K UHDTV and single frequency network (SFN).

scholarly journals ICI Cancellation in OFDM Systems by Frequency Offset Reduction

2014 ◽  
Vol 513-517 ◽  
pp. 3987-3991
Author(s):  
Naveed Ur Rehman ◽  
Lei Zhang ◽  
Muhammad Zahid Hammad ◽  
Emmanuel Anania Mwangosi
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Video Data ◽  
Modulation Scheme ◽  
Ofdm Systems ◽  
Receiver Side ◽  
High Data ◽  
Redundant Data ◽  
Wide Range

The rapid growth within the field of digital communication during the recent years expanded the need for high-speed data transmission to support a wide range of services such as: video, data and voice in wireless communication systems, etc. Orthogonal frequency division multiplexing (OFDM) and a multicarrier modulation scheme are employed to achieve the high data rates. Since OFDM is very much sensitive to carrier frequency offsets, which cause the Inter-carrier Interference (ICI) leads to mitigation of this ICI is necessary. The objectives of this paper are to, proposed an efficient ICI self-cancellation scheme to mitigate the effect of ICI on OFDM systems. For this purpose, a redundant data is transmitted onto adjacent sub-carriers such that the ICI between adjacent sub-carriers cancels out at the receiver side. One data symbol is modulated into a group of adjacent sub carriers with a group of weighting coefficients. At the receiver side, the received signals are linearly combined on these sub carriers with proposed coefficients. The residual ICI contained in the received signals can then be further reduced. This study provides significant carrier-to-interference power ratio (CIR) improvement, which has been studied theoretically and supported by simulations. Since no channel equalization is required to reduce ICI, so the proposed scheme doesnt increase the system complexity.

Optimizing Broadcast Spectrum through the Planning of Digital Television Network

2021 ◽  
Vol 16 (2) ◽  
pp. 31-40
Author(s):  
A.O Gbenga-Ilori ◽  
O. I. Ladipo
Keyword(s):  
Coverage Probability ◽  
Single Frequency ◽  
Digital Television ◽  
Network Coverage ◽  
Spectrum Utilization ◽  
Single Frequency Network ◽  
Television Network ◽  
Digital Terrestrial Television ◽  
Digital Dividend ◽  
Analogue To Digital

The transition from analogue to digital television promises an enormous digital dividend that can translate to spectrum resource provision for other services. In this work, the size of the spectrum that can be released as dividend after digital switchover in some selected States of Nigeria is estimated. First, the present analogue television (ATV) network coverage is compared with predicted digital terrestrial television (DTTV) network coverage during a simulcast period, and after ATV switch-off. The predicted DTTV network is initially planned with a multi-frequency network (MFN) and analysis showed that DTTV had a 12.5% improvement in spectrum utilization compared to ATV while achieving a better coverage probability of 95.3%. This work predicted further spectrum savings with the use of a single-frequency network (SFN) design for DTTV network planning. The analysis done showed that 87.5% of the ATV spectrum could be saved for other services after the transition to DTTV using SFN. Keywords: Digital television, SFN, MFN, Spectrum, dividend

scholarly journals IMPLEMENTATION OF FPGA-BASED DVB-T2 TRANSMITTER FOR A SECOND GENERATION DIGITAL TERRESTRIAL TELEVISION BROADCASTING SYSTEM

2021 ◽  
Vol 7 (1) ◽  
pp. 30-32
Author(s):  
Nguyen Huy Hoang ◽  
◽  
Tran Van Nghia ◽  
Le Van Ky ◽  
◽  
...  
Keyword(s):  
Channel Coding ◽  
Orthogonal Frequency Division Multiplexing ◽  
Second Generation ◽  
Single Frequency ◽  
System Generator ◽  
Television Broadcasting ◽  
Field Programmable ◽  
Broadcasting System ◽  
Digital Transmitter ◽  
Digital Terrestrial Television

Nowadays, with strong development of Science and Technology, integrated circuits continue to dominate not only in the field of digital information. Over the last several years, Technological television industry has taken huge strides and powerful transformation to meet with government’s policy about digitization of television all over the country in period 2015 – 2020. Stemming from the practical needs of “localization of products” and mastering of technological design of DVB-T2 transmitter (Digital Video Broadcasting – Terrestrial for Second generation), the authors have made an effort to research in algorithm, designed and tested in Field Programmable Gate Array (FPGA) technology. DVB-T2 is mainly aimed to replace the current standard DVB-T. The main motivation of DVB-T2 is to provide broadcasters with more advanced and efficient alternative to DVB-T standards. In DVB-T2 transmitter system, digital audio, video, and other data are compressed into a single signal to be transmitted on a single RF channel, using orthogonal frequency-division multiplexing (OFDM) with concatenated channel coding and interleaving. The higher offered bit rate makes it a suited system for carrying HDTV signals on the terrestrial TV channel. The next generation broadcasting systems should be designed to make full use of spectral resources while providing reliable transmissions in order to enable services like multichannel HDTV (High Definition Television) and innovative data casting services. The efficient usage of the radio spectrum can be achieved by the introduction of Single Frequency Networks (SFN). Digital transmitter DVB-T2 implemented on FPGA using a software Xilinx System Generator for DSP tool and Xilinx ISE Design Suite 14.7. System Generator for DSP is in conjunction on environment MATLAB-Simulink that is capable of simulating the proposed hardware structures that is synthesized and implemented by the programmable elements in Field-programmable Gate Arrays. In this project, adaptative MPEG-TS bitrate converter is designed to allows to increasing or reducing the MPEG TS rate by adding or filtering NULL packets. The entire digital transmitter DVB-T2 is integrated in one chip Xilinx FPGA Kintex-7 XC7K325T-1FFG676. Experimental design on development Kit NetFPGA-1G-CML of Digilent Corporation is performed at design department of technology center of Vietnamese Communications Television Development JSC. Authors are continuing to improve products, put into practical applications to replace the digital terrestrial television broadcasting stations that are being used in Vietnam. The article named “Implementation of FPGA-based DVB-T2 transmitter for a second generation digital terrestrial television broadcasting system” presents the research results, design methods, test results to compare, evaluate the accuracy of algorithm implementation. The results open up new directions for technological television in Vietnam.

scholarly journals Fixed Reception Performance of FDM-based Transmission System for Advanced ISDB-T

2020 ◽  
Vol 2020 (6) ◽  
pp. 9-20
Author(s):  
Takuya Shitomi ◽  
◽  
Shingo Asakura ◽  
Shogo Kawashima ◽  
Akihiko Sato, ◽  
...  
Keyword(s):  
Channel Coding ◽  
Forward Error Correction ◽  
Transmission System ◽  
Coded Modulation ◽  
Transmission Capacity ◽  
Frame Structure ◽  
Modulation Scheme ◽  
High Spectral Efficiency ◽  
Digital Terrestrial Television ◽  
T System

With the aim of improving the quality and expanding the functions of digital terrestrial television broadcasting services, we have been developing an advanced transmission system that inherits key features of the current Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) system, which employs hierarchical transmission based on frequency division multiplexing (FDM) and a segment structure. The advanced ISDB-T system has a new signal frame structure that enables bandwidth to be flexibly allocated to multiple services for different reception scenarios, such as fixed reception and mobile reception, compared with ISDB-T. By introducing transmission technologies such as the latest forward error correction and modulation scheme, this specification has high spectral efficiency and transmission robustness, i.e., the transmission capacity increases by about 10 Mbps for the same required carrier to noise ratio (CNR) in comparison with the current ISDB-T system, or the required CNR can be reduced by about 7 dB for the same transmission capacity. We describe the channel coding scheme and evaluated the performance of bit-interleaved coded modulation (BICM) in simulations. This paper provides a BICM selection guideline based on the simulation results for fixed reception scenarios toward the practical application of advanced ISDB-T.

scholarly journals Frame Synchronization for the DTMB Systems with the Multiple-Antenna Receivers

2012 ◽  
Vol 6-7 ◽  
pp. 434-438
Author(s):  
Zi Wei Zheng
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Orthogonal Frequency Division Multiplexing ◽  
Wide Band ◽  
Multipath Fading ◽  
Spectrum Efficiency ◽  
Digital Television ◽  
Multiple Antenna ◽  
Frame Synchronization ◽  
Receiver System

Faced with the challenges of modern communication, high data throughput requirements, extensive research has been paid to broadband modulation. The multi-carrier modulation is one of the most important wide band modulation techniques. Orthogonal frequency division multiplexing (OFDM) is an effective blow to the broadcast channel multipath fading and high bit rate transmission multi-carrier modulation technology of wireless channels, it is widely used in modern digital television terrestrial broadcasting (DTTB) system to support performance bandwidth-efficient multimedia services with the aid of inverse fast Fourier transform and fast Fourier transform operation. Multiple-antenna transmitter and receiver technology allows several times to achieve data transmission rates and spectrum efficiency and the use of multiple transmit antennas and multiple receive antennas through spatial processing. The Digital Terrestrial Multimedia Broadcasting (DTMB) system with the multiple-antenna receiver is considered in this paper. Digital Terrestrial Multimedia Broadcasting (DTMB) has three kinds of Frame Head mode with PN420/PN595/PN945 as training sequences for the time domain synchronous OFDM (TDS-OFDM). At the receiver side with multiple antennas, Frame Head mode detection should be done. In this paper, the frame synchronization scheme is proposed for the DTMB systems with the multiple-antenna receiver. System performance studies under different channel situations are used to verify the efficiency of the proposed scheme for the DTMB systems with the multiple-antenna receiver.

Introduction

2018 ◽  
Author(s):  
Anna-Maria Hartmann
Keyword(s):  
Sixteenth Century ◽  
Early Modern ◽  
Literary History ◽  
First Generation ◽  
Early Modern England ◽  
Related Material ◽  
Wide Range ◽  
The World ◽  
Early English

Mythographies were books that collected, explained, and interpreted myth-related material. Extremely popular during the Renaissance, these works appealed to a wide range of readers. While the European mythographies of the sixteenth century have been utilized by scholars, the short, early English mythographies, written from 1577 to 1647, have puzzled critics. The first generation of English mythographers did not, as has been suggested, try to compete with their Italian predecessors. Instead, they made mythographies into rhetorical instruments designed to intervene in topical debates outside the world of classical learning. Because English mythographers brought mythology to bear on a variety of contemporary issues, they unfold a lively and historically well-defined picture of the roles myth was made to play in early modern England. Exploring these mythographies can contribute to previous insights into myth in the Renaissance offered by studies of iconography, literary history, allegory, and myth theory.

scholarly journals Recent Advancements in Polymer/Liposome Assembly for Drug Delivery: From Surface Modifications to Hybrid Vesicles

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1027
Author(s):  
Vincenzo De Leo ◽  
Francesco Milano ◽  
Angela Agostiano ◽  
Lucia Catucci
Keyword(s):  
Drug Delivery ◽  
First Generation ◽  
Phospholipid Bilayer ◽  
Bioactive Molecules ◽  
Systemic Delivery ◽  
Molecular Weights ◽  
Liposome Preparation ◽  
Wide Range ◽  
Liposome Surface

Liposomes are consolidated and attractive biomimetic nanocarriers widely used in the field of drug delivery. The structural versatility of liposomes has been exploited for the development of various carriers for the topical or systemic delivery of drugs and bioactive molecules, with the possibility of increasing their bioavailability and stability, and modulating and directing their release, while limiting the side effects at the same time. Nevertheless, first-generation vesicles suffer from some limitations including physical instability, short in vivo circulation lifetime, reduced payload, uncontrolled release properties, and low targeting abilities. Therefore, liposome preparation technology soon took advantage of the possibility of improving vesicle performance using both natural and synthetic polymers. Polymers can easily be synthesized in a controlled manner over a wide range of molecular weights and in a low dispersity range. Their properties are widely tunable and therefore allow the low chemical versatility typical of lipids to be overcome. Moreover, depending on their structure, polymers can be used to create a simple covering on the liposome surface or to intercalate in the phospholipid bilayer to give rise to real hybrid structures. This review illustrates the main strategies implemented in the field of polymer/liposome assembly for drug delivery, with a look at the most recent publications without neglecting basic concepts for a simple and complete understanding by the reader.

scholarly journals Miniaturized Wideband Loop Antenna Using a Multiple Half-Circular-Ring-Based Loop Structure and Horizontal Slits for Terrestrial DTV and UHD TV Applications

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2916
Author(s):  
Junho Yeo ◽  
Jong-Ig Lee
Keyword(s):  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Circular Ring ◽  
Loop Antenna ◽  
Digital Television ◽  
Loop Structure ◽  
High Definition ◽  
Circular Sector ◽  
Feed Line ◽  
Length Reduction

A miniaturized wideband loop antenna for terrestrial digital television (DTV) and ultra-high definition (UHD) TV applications is proposed. The original wideband loop antenna consists of a square loop, two circular sectors to connect the loop with central feed points, and a 75 ohm coplanar waveguide (CPW) feed line inserted in the lower circular sector. The straight side of the square loop is replaced with a multiple half-circular-ring-based loop structure. Horizontal slits are appended to the two circular sectors in order to further reduce the antenna size. A tapered CPW feed line is also employed in order to improve impedance matching. The experiment results show that the proposed miniaturized loop antenna operates in the 460.7–806.2 MHz frequency band for a voltage standing wave ratio less than two, which fully covers the DTV and UHD TV bands (470–771 MHz). The proposed miniaturized wideband loop antenna has a length reduction of 21.43%, compared to the original loop antenna.

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.

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