ATSC System Research Articles

Artificial Intelligence-Based Adaptive Traffic Signal Control System: A Comprehensive Review

The exponential increase in vehicles, quick urbanization, and rising demand for transportation are straining the world’s road infrastructure today. To have a sustainable transportation system with dynamic traffic volume, an Adaptive Traffic Signal Control system (ATSC) should be contemplated to reduce urban traffic congestion and, thus, help reduce the carbon footprints/emissions of greenhouse gases. With dynamic cleave, the ATSC system can adapt the signal timing settings in real-time according to seasonal and short-term variations in traffic demand, enhancing the effectiveness of traffic operations on urban road networks. This paper provides a comprehensive study on the insights, technical lineaments, and status of various research work in ATSC. In this paper, the ATSC is categorized based on several road intersections (RIs), viz., single-intersection (SI) and multiple-intersection (MI) techniques, viz., Fuzzy Logic (FL), Metaheuristic (MH), Dynamic Programming (DP), Reinforcement Learning (RL), Deep Reinforcement Learning (DRL), and hybrids used for developing Traffic Signal Control (TSC) systems. The findings from this review demonstrate that modern ATSC systems designed using various techniques offer substantial improvements in managing the dynamic density of the traffic flow. There is still a lot of scope to research by increasing the number of RIs while designing the ATSC system to suit real-life applications.

안드로이드 플랫폼에서 모바일 방송 모듈을 위한 시스템 개발

공중파 TV방송의 디지털 전환에 따른 막대한 자금이 투여되는 현 상황에서 지상파 방송의 매체 영향력은 신규의 유료 매체인 디지탈 케이블 TV 및 IPTV로 인해 감소될 가능성이 크기 때문에 신규 신성장 동력으로 모바일 TV시장을 확장이 필요하다. 국내 지상파방송 사업자들이 기존의 DMB사업으로 크게 성과를 보지 못하고 있는 실정에서 ATSC-M/H 기술 도입으로 방송 시스템 공급과 모듈의 수요가 증가할 것이 예상되고 있다. ATSC-M/H는 모바일 서비스를 위한 별도의 주파수 할당이 필요 없고 기존 ATSC 시스템에 간섭을 주지 않으면서 동시방송을 수행할 수 있는데, 안드로이드(Android) 휴대단말기 상에서 미국형 모바일 방송 수신 모듈을 개발하고자 한다. 본 논문은 안드로이드 플랫폼에서 임베디드 시스템이 적용되는 방송 모듈을 휴대 단말기에서 모바일 방송을 볼 수 있는 소프트웨어 모듈을 설계하고자 한다.

A Design of Equalization Digital On-Channel Repeater for Single Frequency Network ATSC System

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper presents a guideline for designing an Equalization Digital On-Channel Repeater (EDOCR) and proposes an efficient method to implement it. The major concerns in the design of an EDOCR are shortening the system delay, maintaining synchronization between a main transmitter and an EDOCR, obtaining high signal to noise ratio (SNR) output, and enabling operation in an environment of adjacent channel interference. The short system delay is achieved adopting a demodulation scheme without an additional lowpass filter to remove harmonics, an intelligent slicer of a trellis decoder with a trace back depth of 1 for equalization, and an equi-ripple filter for the 8-VSB pulse shaping filter. To maintain the synchronization, the frequency offset information extracted from the received signal is reflected on a re-transmitting signal. Distinguished features of the EDOCR are adaptive equalization with the intelligent slicer which corrects symbol errors caused by on-air interface including the signal loopback, and the signal processing scheme which demodulates the received signal to a baseband symbol and re-modulates the symbol. Hence, the EDOCR can produce an exact replica of the main transmitter's signal with high SNR although there may be adjacent channels and input signal is distorted by multipath and noise. Finally, the performance evaluation of the designed EDOCR in both simulation and laboratory tests are presented and implementations of single frequency networks employing EDOCRs are discussed. </para>

The ATSC Transport Layer, Including Program and System Information Protocol (PSIP)

The basic concepts of the transport layer of the ATSC digital television system, including multiplexing, timing, and synchronization, are presented. Constraints on and extensions to the MPEG-2 Systems standard are discussed, including the important extension that adds Program and System Information Protocol (PSIP). Transport related aspects of private data carriage and conditional access are also described.

In-Band Control of PSIP Translation

The ATSC Program and System Information Protocol (PSIP) provides certain information in a digital television (DTV) broadcast stream that helps a DTV receiver correctly identify and tune to the virtual channels in the broadcast stream. In situations where a DTV signal is received and retransmitted, some of the PSIP information may need to be translated in order to accurately reflect the parameters of the new transmission. This paper proposes an in-band control mechanism that uses the broadcast stream itself to carry remote control information to a PSIP translation system in such cases, and it discusses the advantages of this method over others.

Frequency synchronization algorithm robust to pilot distortion in ATSC system

A frequency synchronization algorithm is proposed that is robust to pilot distortion in the ATSC system. Since conventional frequency synchronization algorithms only estimate the frequency offset from the received pilot, synchronization can not be achieved if the pilot is severely distorted. Accordingly, the proposed algorithm compensates most of the frequency offset using the symmetry property of the ATSC signal spectrum. However, because information about the phase offset is unobtainable from the symmetry property, the estimation may still have an offset due to asymmetric channel distortion. To overcome such problems, a second step compensates the remaining frequency and phase offsets using a conventional pilot-based algorithm. As a result, the proposed algorithm increases the estimation range of the frequency offset and can achieve perfect synchronization if the transmitted pilot level is greater than 25 percent of the original level.