An Effective Frame Synchronization Technique for DRM System

It is envisioned that all broadcasting systems will be digitalized in future. New services and more information require high data rates for broadcasting systems. There are many digital audio broadcasting standards in the world, such as DAB (Digital Audio Broadcasting) in Band III and Band L, DRM (Digital Radio Mondiale)and HD Radio in AM band and FM band. In this paper, we will present a general purpose SDR (Software Defined Radios) platform to realize digital audio broadcasting systems, including transmission and reception. In the platform, we not only can test novel digital technologies but also experiment with different service modes.

The move from analogue to digital HF broadcasting using the Digital Radio Mondiale (DRM) standard poses some problems of transition that have not been present for the transition of other digital broadcasting systems most notably that there is little or no additional spectrum available to support the simulcast period when both analogue and digital transmissions will coexist. This paper explores the possibilities of using the in-built capabilities of the DRM standard to offer a propagation based solution to the lack of spectrum.

Advances in wireless communications have enabled various technologies for wireless digital communication. In the field of digital radio broadcasting, several specifications have been proposed, such as Eureka-147 and digital radio mondiale (DRM). These systems require a new spectrum assignment, which incurs heavy cost due to the depletion of the available spectrum. Therefore, the in-band on-channel (IBOC) system has been developed to work in the same band with the conventional analog radio and to provide digital broadcasting services. This paper discusses the function and algorithm of the high definition (HD) radio frequency modulation (FM) digital radio broadcasting system. Content includes data format allocation, constellation mapping, orthogonal frequency division multiplexing (OFDM) modulation of the transmitter, timing synchronization, OFDM demodulation, integer and fraction carrier frequency (integer carrier frequency offset (ICFO) and fractional CFO (FCFO)) estimation, and channel estimation of the receiver. When we implement this system to the field programmable gate array (FPGA) based on a hardware platform, both theoretical and practical aspects have been considered to accommodate the available hardware resources.

Orthogonal frequency division multiplex-single frequency network (OFDM-SFN) has been widely used in the digital audio broadcasting system (DAB) and the terrestrial digital video broadcasting system (DVB-T) as a scheme of downlink broadcasting service. A novel system structure of single frequency cellular network (SFCN) is proposed by applying OFDM-SFN to conventional cellular systems. Transmitter macrodiversity and receiver selective diversity are adopted in the downlink and the uplink respectively. Theoretical analysis and numerical simulation in comparison with conventional cellular systems demonstrate the performance improvement of the proposed system.

Modern radio-communications have begun the transition process from analog to digital radio-communications and broadcasting. During this transition process, main changes are required in exciter units of transmitters. The architecture of transmitters themselves is the same for both digital and analog broadcasting, but the exciters used for digital broadcasting have to create analog RF exciting signals for the transmitters from the digital data stream. The most common modulation procedure used in digital broadcasting systems is OFDM with QPSK or some kind of QAM keying of sub carriers. Apart from RF signal generation, the exciters are often responsible for control of the whole system, because control data is often included in the digital stream distributed from the broadcast center to the transmitters

From home entertainment we know a number of digital entertainment sources which we cherish. Especially Digital Broadcasting, such as DAB, DVB, HD-Radio and SDARS just to name a few, are entering the automotive market. Premium car manufacturers are offering DAB, DVB-T as well as HD-Radio and SDARS as digital sound broadcasting for their customers. However, a lot of efforts need to be undertaken to get good performance. This paper deals with answering the often asked question, why digital broadcasting systems in vehicular environments do not perform as good as their theoretical performance should intend. With an excessive measurement campaign with a number of premium car manufacturers in Germany, we found three main arguments; a) the digital modulation becomes week in terms of bit-errors with enhanced data rates b) wideband modulation schemes, such as COFDM for example, are fragile in fading environments, especially reactive on frequency selective fading and c) used coding and modulation techniques can cope with single-frequency and single-event interferences well but not with permanent broadband interference, which are often found in EMC signatures in well-equipped luxury cars.

There is able to be critical performance impairment because satellite digital broadcasting system such as DVB-S2 is sensitive to heavy rain environment. This feature of the satellite channel does not only make users be able to give inconvenient broadcasting service but they cannot see the service. Spread spectrum technique is the new proposal which can overcome those problems that are generated due to rain attenuation. Applying spread spectrum to DVB-S2 system, we examine how effective the technique is in the broadcast system. Assuming that signal power and channel bandwidth are same in the proposed system and the original system, the reason why spread spectrum technique is effective in heavy rain environment will be demonstrated. And using computer simulation, the performance improvement is shown.

As an effective technique for combating multipath fading and for high-bit-rate transmission over wireless channels, orthogonal frequency division multiplexing is extensively used in modern digital television terrestrial broadcasting systems to support high performance bandwidth-efficient multimedia services. Accurate channel estimation is important for the application of simple channel equalization for the broadband multi-carrier orthogonal frequency division multiplexing systems and the accuracy of the channel estimation is crucial to the performance of the overall orthogonal frequency division multiplexing system in terms of the symbol error rate. In this paper, a robust channel estimation scheme is proposed for the receiver of the time domain synchronous orthogonal frequency division multiplexing based Chinese digital television terrestrial broadcasting systems. Simulations under different channel situations show that the proposed channel estimation scheme can also effectively solve the phase noise problem existing at the receiver and verify the efficiency of the proposed scheme.

Next-generation digital broadcasting system transmits the DASH segment files. Delays and inefficient use of resources are the major challenges in the transmission of DASH segment files in broadcasting systems. Because the size of DASH segment files varies even though the files have the same quality, and broadcasting systems uses the fixed resource. Delay is an important problem in broadcasting systems because these are real-time systems. Therefore, next-generation digital broadcasting systems should minimize delays and use resource efficiently. This paper proposes a transmission model that can analyze delays as well as efficient use of resources.

이 논문에서는 계층변조를 적용하는 AT-DMB (advanced terrestrial digital multimedia broadcasting) 시스템에 적용할 수 있는 블라인드등화 기법을 제시하고 그 성능을 살펴본다. AT-DMB 시스템은 기존 T-DMB의 DQPSK (differential quadrature phase-shift keying) 신호와 역방향 호환성을 보장하고 더 높은 데이터 전송률을 지원하기 위해 16-QAM (quadrature amplitude modulation) 계층변조 방식을 적용한다. 이 결과 SNR (signal to noise ratio)에 따라 기존 T-DMB 심볼과 추가된 심볼은 서로 다른 판정오율 (decision error rate)을 가진다. 따라서 판정한 신호로부터 채널을 추정할 때 판정오율이 낮은 선순위 심볼과 판정오율이 높은 후순위 심볼의 신뢰도에 따라 다른 가중치를 줌으로써 판정치의 전체적인 신뢰도를 향상시킬 수 있다. 이 논문에서는 계층변조에 따른 비트 오율(bit error rate) 성능의 악화정도를 분석하고, 모의실험을 통해 판정신호의 신뢰도에 따라 가중치를 주는 제안방식이 가중치를 주지 않은 경우에 비해 비트 오율 성능이 향상됨을 확인하였다. In this paper, we propose a blind equalization method for advanced terrestrial digital multimedia broadcasting (AT-DMB) systems which use hierarchical modulation. The AT-DMB system adopts hierarchical 16-ary quadrature amplitude modulation (16-QAM) to ensure backward-compatibly with the differential quadrature phase shift keying (DQPSK) signal of the legacy terrestrial digital multimedia broadcasting (T-DMB) systems and to support higher transmission rate. Due to the hierarchical modulation, the conventional T-DMB signal and the additional signal have different error rate at same signal to noise ratio (SNR). By weighting the decided symbols differently according to the reliability of the symbols, i.e., high priority symbol with low error rate and low priority symbol with high error rate, we can improve the channel estimation accuracy. In this paper, we analyze SNR loss by hierarchical modulation and confirm it through simulations. Moreover, through simulations, we verify that the proposed weighting method improve BER compared to the no-weighting method.

Background: It is a common fact that the rapid development of technology influenced many aspects of the world, including mass communication. Television, as the most popular and familiar broadcast media in Indonesia, has experienced several changes due to the presence of advanced technology. One of the significant transformations is the transition from analog to digital broadcasting systems. The new era of digital broadcasting could improve the performance and quality of digital television itself. Purpose: This recent study aimed to obtain an overview of the realization carried out by one of the local private broadcasting institutions in Banten, JPM TV. Methods: Using a qualitative case study along with in-depth interviews and observation as data collection techniques, this study examines JPM TV from various aspects in realizing digital TV broadcasts in Banten Province. Results: The study’s findings highlighted that JPM TV strives to realize digital broadcasting by gradually replacing equipment with tools that support digital broadcasting and elements of human resources trained and prepared with special internal and external training. JPM TV also collaborated with LPPM (Mix Broadcasting Organizing Agency), namely Mix Metro TV. The ongoing process is coordinated with the government. Obstacles faced during the migration process are the socioeconomic conditions of the people who have not been able to support the digital broadcasting process, which is characterized by the difficulty of obtaining digital broadcasting at relatively low prices; besides that, it is also necessary to increase the capacity of Human Resources (HR) so that television shows are more comfortable to watch. Implications: One of the implications is that the government must innovate to provide incentives that can stimulate the readiness of the digital broadcasting ecosystem.

The theoretical analysis of a digital satellite broadcasting system in the presence of phase noise is performed. An effective technique to design the carrier recovery circuit is also presented based on the analyzed loop parameters, such as degradation loss due to phase noise, average time to cycle slip, and carrier signal acquisition time. It is possible to design a system providing the optimal service and satisfying service requirements for a digital satellite broadcasting system. In this paper, the carrier recovery loop that provides optimal performance in the presence of phase noise exhibits the parameters of 0.707 for damping factor and 40 kHz for noise bandwidth. The designed phase-locked loop indicates a performance of 0.26 dB for impairment due to phase noise at 10/sup -3/ BER, 3.88/spl times/10/sup 6/ hours for average time to cycle slip, and 34 msec for carrier signal acquisition time. The carrier acquisition time of the designed carrier recovery circuit is in accordance with the analyzed result.

In this paper, we present the design, implementation and validation of a cable terminal platform for high speedy transmission. The simulator is implemented on a personal computer to validate performance. The proposed simulation system has designed for 400 Mbps down streaming service of terminal platform for digital cable broadcasting system. The proposed simulation conducts FTP file service using TCP/IP protocols based on cable broadcasting system

A public process has been in place in the United States for six years to establish an HDTV terrestrial broadcasting standard. The process, having moved through a planning phase, a competition phase, and an examination phase, has now entered a cooperation phase. Remarkable progress has been made/spl minus/a testament to the process. During 1994 the American digital HDTV terrestrial broadcasting system will be tested, fully documented, and recommended to the FCC for adoption.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The discussion of mobile multimedia broadcasting technologies and service implementation in this chapter is limited to the broadcasting network based scheme can be received by portable or hand-held devices with a small screen. Similar to DTTB systems, digital mobile multimedia broadcasting systems are designed for high-data-throughput (to support multiple low-data-rate services) transmission through wireless channels (VHF/UHF bands in terrestrial, S- or L-band for satellite networks). The chapter summarizes the features of DVB-H, Advanced Television Systems Committee (ATSC)-M/H, China Multimedia Mobile Broadcasting (CMMB), and the new released DVB Next Generation Broadcasting System to Handheld (NGH) standards with the focus on the technical merits of reliable transmission under wireless, mobile environment and the robust reception using the portable or hand-held devices. ATSC-Mobile/Handheld (ATSC-M/H) is the standard for the DTV mobile transmission developed by the ATSC in 2007. The ATSC-M/H system shares the same RF channel of the traditional ATSC broadcast services.