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Sending broadcast messages is an efficient means of communicating in emergency situations, especially during serious disasters. This paper focuses on the digital audio broadcast (DAB) system. First, several new techniques are reported to enhance the emergency warning message (EWM) receiving and display functionalities for both personal and public DAB terminals. Then, a novel bidirectional communication method between two DAB transmitters is proposed, to enable the communication to and from the disaster area and the outside. Experiments show that the EWM can be correctly sent to the intended DAB terminals within 0.2–3 s, and the existing public light emitting diode screens can be expanded as DAB EWM terminals without affecting their normal functions. The bidirectional multimedia communication between two DAB transmitters is also successfully demonstrated. The proposed techniques expand upon the DAB’s existing functionality, and can benefit more people during emergencies. [ABSTRACT FROM AUTHOR]

Mobile broadcasting services are considered effective methods for emergency alert delivery. Terrestrial digital multimedia broadcasting (T-DMB) offers an emergency alert service called automatic emergency alert service (AEAS). However, the conventional AEAS is inefficient in the aspects of alert service channel, disabled T-DMB receiver, and location-based service. Therefore, this paper proposes a novel signaling method in order to overcome the drawbacks of the AEAS. The presented alert system exploits an additional alert channel, which is multiplexed with the conventional T-DMB channel. This paper also addresses the multiplexing approach, which effectively eliminates the interference between the additional alert channel and the TDMB channel. The simulation results confirm that the proposed signaling method effectively offers the emergency alert services in T-DMB1. [ABSTRACT FROM AUTHOR]

With the emergence of new TV media such as digital cable and satellite, the task of finding one's favorite program among hundreds of channels becomes a time consuming job. Furthermore, the channel zapping time of DTV is much longer than that of analogue one. To relieve the time overhead in channel navigation, this paper presents an intelligent channel navigation scheme for DTV channel selectors. The proposed navigation scheme analyzes each person's previous watching behavior in terms of recency and frequency, and then utilizes this information in the control of the up-down channel selector. Simulation studies show that the proposed scheme reduces the seek distance of the DTV channel navigation system by up to 68.7% under various conditions. [ABSTRACT FROM AUTHOR]

In this paper, an efficient design of dual mode deinterleaver for both IEEE 802.16 and digital video broadcasting (DVB) standards is presented. The paper first proposes a systematic data allocation method for the design of matrix transposer which can be used to realize the block deinterleaver adopted by IEEE 802.16 based on the multi- bank memory architecture. In addition, multiple input/output data can be grouped together in order to further reduce the memory access frequency such that the required number of banks and ports for the memory can be both reduced. Similarly, the multi-bank memory design approach can also be applied for the byte-level convolutional deinterleaver adopted in DVB system by realizing the multiple delay branches as the circular buffer. Finally, these two different deinterleaving standards can be further integrated . into a single design suitable for those dual-mode communication systems. Our implementation results show that the dual mode deinterleaver can run up to 150 Mhz, and consume about 38.5k gates. The same design methodology can also be applied for the design of interleavers. [ABSTRACT FROM AUTHOR]

In this paper, we suggest a synchronization receiver for MIMO-OFDM based mobile broadcasting system. A MIMO-OFDM receiver with algorithms for tracking of residual frequency offset (RFO) and sampling frequency offset (SFO) is designed and simulated. The proposed synchronization and compensation schemes are applied to IEEE 802.16e WiMAX and its performance is investigated by computer simulations in terms of mean square error (MSE) and bit error rate (BER). The proposed RFO and SFO estimator has a fast convergence and a small residual degradation even for high speed mobile station. [ABSTRACT FROM AUTHOR]

A new national standard for Digital Multimedia Broadcasting (DMB) has been announced in Korea to provide high quality digital audio, video, and data broadcasting services to fixed, mobile, and portable receivers. We have developed the world's first DSP/FPGA implementation of the portable DMB receiver, complete with an RF receiver, a 6.4-inch LCD display, and audio/video/data decoders. In this paper, we present the design, implementation, and performance of this portable DMB receiver. First, we provide a brief overview of the DMB system and the audio/video coding tools supported by it, i.e., MPEG-4 BSAC and MPEG-4 Part 10 A VC/H. 264. We discuss the low-power high-performance design of the DMB receiver, focusing particularly on the audio/video decoding parts. Finally, we illustrate the performance of the portable DMB receiver that operates in real-time at the overalifrequency of 25 MHz. [ABSTRACT FROM AUTHOR]

One of the enablers for new consumer electronics based products to be accepted in to the market is the availability of inexpensive, flexible and multi-standard chipsets and services. DVB-T, the principal standard for terrestrial broadcast of digital video in Europe, has been extremely successful in leading to governments reconsidering their targets for analogue television broadcast switch-off. To enable one further small step in creating increasingly cost effective chipsets, the ODFM deterministic equalizer has been presented before with its application to DVB-T. This paper, discusses the test set-up of a DVB- T compliant baseband simulation that includes the deterministic equalizer and DVB-T standard propagation channels. This is then followed by a presentation of the found inner and outer Bit Error Rate (BER) results using various modulation levels, coding rates and propagation channels in order to ascertain the actual performance of the deterministic equalizer. [ABSTRACT FROM AUTHOR]

Nowadays, broadcasters deliver ultra-high resolution video to their consumers. This live video is sent to a set-top box for display on a television. However, if one or more users in the home want to view the same video on their personal mobile devices with a lower display resolution and limited processing power, decoding the original ultra-high resolution video would result in stuttering and quickly drain the battery life on these devices. To enable a satisfactory consumer experience, the resolution of the video stream should be adapted to the target mobile device at the set-top box. The aim of this paper is to investigate the performance of different machine learning strategies to arbitrary downsize video pre-encoded with the high efficiency video coding standard (HEVC). These machine learning techniques exploit correlation between input and output coding information to predict the splitting behavior of HEVC coding units. Several machine learning algorithms are optimized. Additionally, both online and offline training strategies are tested. Of the tested algorithms, online-trained random forests achieve the best compression-efficiency with a bit rate increase of 5.4% and an average complexity reduction of 70%1. [ABSTRACT FROM AUTHOR]

Personal Video Recorders provide the facility of recording live broadcast streams thus users can replay their recordings whenever they want. However, during playback of those recorded streams, users are isolated from the live content (e.g., latest news,) in which they might be interested. In this paper, we propose an MPEG-2 Transport Stream compatible method which can inform the user about live content that's in user interest area during playback. The method-specific structures, algorithms and an implementation on a Linux platform are presented in the paper. [ABSTRACT FROM AUTHOR]

The emergency broadcasting system based on T-DMB network have been developed and installed in tunnel environment. This paper describes implementation and field test results of the T-DMB emergency broadcasting system in practical tunnel environment. The developed emergency broadcasting system can execute the on-channel repeating function in common environment. And the system provides emergency broadcasting service in accident or disaster environment to legacy T-DMB receivers. According to the field test results, the smooth operation is evaluated for both emergency broadcasting function and on-channel repeating function with legacy T-DMB receivers1. [ABSTRACT FROM PUBLISHER]

Carrier frequency offset (CFO) synchronization is a crucial issue in the implementation of orthogonal frequency division multiplexing (OFDM) systems. Synchronization is performed in two stages: acquisition and tracking. After a first estimation and correction of the CFO performed in the acquisition stage, there still remains a residual frequency offset (RFO) due to real system conditions. This paper presents two new schemes for RFO tracking affecting a digital video broadcasting (DVB-T) system. Due to the nature of DVB-T, where data transmission is performed continuously, RFO tracking needs to be performed accurately during all the data length in order to correct the ICI and the phase rotation impairment produced by this RFO. Comparisons of the novel algorithms with two previously reported estimators in terms of mean square error (MSE), complexity and speed of convergence are performed. The proposed schemes improve performance and/or speed of convergence compared to the conventional estimators with a reduction of the computational complexity. Furthermore, a combined technique for RFO tracking involving the two new schemes is proposed. This method obtains the best results in terms of accuracy, convergence and complexity. [ABSTRACT FROM AUTHOR]

This paper presents an efficient VLSI architecture and implementation for LDPC decoder used in China Multimedia Mobile Broadcasting (CMMB) systems. An area-efficient layered decoding architecture based on min-sum algorithm is incorporated in the design. A novel split-memory architecture is developed to efficiently handle the weight-2 submatrices that are rarely seen in conventional LDPC decoders. In addition, the check-node processing unit is highly optimized to minimize complexity and computing latency while facilitating a reconfigurable decoding core. The proposed design is implemented using 90 nm CMOS technology with the core area of approximately 4.4 mm² and the standard supply voltage 1.0 V. The decoder can achieve the maximum throughput of 228 Mb/s for rate ½ and 342 Mb/s for rate ¾ at 15 iterations of layered decoding. Therefore, it can be deployed on the CMMB mobile platform. [ABSTRACT FROM AUTHOR]

Digital Video Broadcasting for Handheld (DVB-H) is one of the wireless technologies that provide modern digital television services. The main objective of this paper is to propose a method to evaluate the performance of mobile rebroadcaster in terms of symbol error rate, taking into account antenna effects and the Angle of Arrival statistics. A correction factor is derived from concepts as the Mean Effective Gain, which joined to a closed-form expression for the symbol error probability, allows predictions about the antenna impact on the broadcaster. The quantitative evaluation of the analysis identifies an important SNR reduction from 4 dB to 10 dB, depending on the environment. [ABSTRACT FROM AUTHOR]

Histogram equalization is a simple and effective method for contrast enhancement as it can automatically define the intensity transformation function based on statistical characteristics of the image. However, it tends to alter the brightness of the entire image, which it is not suitable for consumer electronic products, where preservation of the original brightness is essential to avoid annoying artifacts. This paper presents a new contrast enhancement method for generalization of the existing bihistogram equalization (BHE) and recursive mean-separate histogram equalization (RMSHE) methods. The proposed method is referred to gain-controllable clipped histogram equalization (GC-CHE) to provide both histogram equalization and brightness preservation. More specifically adaptive contrast enhancement is realized by using clipped histogram equalization with controllable gain. The clipping rate is determined based on the mean brightness, and the clipping threshold is determined based on the clipping rate. The clipping rate is adaptively controlled to enhance the contrast with preserving the mean brightness. It is mathematically proven that the mean brightness of the output image converges to that of the input image with adaptive controlled. Simulation results show that the proposed GC-CHE method outperforms existing histogram-based methods, such as HE, BHE, and RMSHE, in various situations. [ABSTRACT FROM AUTHOR]

Convergence between broadcasting services and telecommunication services and provisioning of rich media services are two major requirements that recent mobile broadcast TV services try to satisfy. Although there exist independent technologies and international standards for each of the requirements, few efforts have been paid for providing solutions supporting these requirements together. In this paper, we present a standard-based implementation for mobile handsets in support of rich media enabled mobile broadcast TV services. [ABSTRACT FROM AUTHOR]

In recent years, advanced data broadcasting services, which provide viewers with multimedia data on digital television, have drawn growing interest. At the same time, there is file-sharing peer-to-peer service on digital television field. However, few studies pay attention to their convergence that is data broadcasting can help peer-to-peer service. This paper studies file-sharing peer-to-peer application among set -top boxes in bidirectional HFC networks. The study proposes the new architecture that using data carousel completes search work in peer-to-peer system. Finally, the experiment demonstrates advantages of the proposed strategy in hybrid peer-to-peer system. [ABSTRACT FROM AUTHOR]

Current satellite digital broadcasting transmission system "ISDB-S " employs digital modulation schemes, BPSK, QPSK, and 8PSK combined with a concatenated code consists of convolution code and Reed- Solomon code. While, in recent years, transmission systems adopted LDPC codes have been developed. Multi-level digital modulation schemes combined with LDPC codes can achieve more efficient transmission. In this paper, we propose a new transmission system employed LDPC, multi-level modulation and advanced TMCC signal. [ABSTRACT FROM AUTHOR]

This paper presents a bidirectional interactive ontents player for Terrestrial Digital Multimedia ~roadcasting (T-DMB). The presented player is capable of ending user requests to a proper return channel server using nformation included in a scene presentation. The player rovides functionality to combine requested data received via ommunication networks with the initially broadcasted ,ontents to present additional information to users. The result a request transmitted back through the broadcasting ietwork can also be presented properly using the presented ilayer'. [ABSTRACT FROM AUTHOR]

Subtitle data carried by MPEG-2 Transport Stream includes texts of dialogs in bitmap graphics format. However, this data is not reachable for the blind audience. In addition, carrying extra compatible data with subtitle packets can be helpful for testing subtitle software automatically and for presenting live content (i.e. latest news or special advertisements). In this paper, we propose a method for converting subtitle data into text format by recognizing characters using neural networks. The converted data can be used for blind television users and testing subtitle software automatically. We also define a new subtitle segment for carrying test comparison data and a new subtitle page for representing live content. We present our implementation on Linux platform. [ABSTRACT FROM AUTHOR]

The interactive media platform(IMP) scheme proposed here provides an efficient solution for interactive digital TV in back-end. The platform actually integrates traditional TV guide system, interactive application execution system and digital video recorder(DVR) system together. The IMP consists of hardware infrastructures and middleware-based system software. This paper addresses a reference solution for interactive digital TV receiver that compliant with DVB-MHP. The architecture of IMP is proposed. The hardware architecture and middleware-based system software architecture are also presented respectively. In broadcast networks, all data including service information and interactive applications are transmitted from front-end to back-end periodically. Thus, broadcast latency is introduced to the platform while receivers processing broadcast data. Considering that broadcast latency has great influences to the platform performance, optimized strategies to reduce such latency while implementing is described in detail. The proposed platform has been implemented and the experimental result shows a good performance. [ABSTRACT FROM AUTHOR]

In this paper, a novel high-performance 8k-point fast Fourier transform(DFT) processor architecture for OFDM digital video broadcasting(DVB) is proposed based on a novel radix-8 FFT architecture. Distributed arithmetic(DA) is used to implement the basic 8-point FFTs directly, where the hardware cost of complex multipliers and adders can be greatly reduced. The twiddle multiplications are performed by CORDIC-based twiddle multipliers. The results show that the proposed processor architecture can greatly save the area cost while keeping a high-speed processing speed, which may be attractive for many real-time DVB-T systems. [ABSTRACT FROM AUTHOR]

In this paper, we present a VLSI design of transport processor for an A VS HDTV decoder SoC. The design provides a flexible data flow, which supports both broadcasting service and IPTV service with DVR capability. The design is characterized by two-bus architecture, in which a RISC CPU is used for control of general purpose and some dedicated hardware for accelerating data processing. The common on-chip SRAM is used to store input transport packets and the intermediate result in order to improve system performance and reduce the area. The design is described in Verilog HDL, simulated with VCS simulator, and implemented using 0.18μm CMOS cell library. The circuit costs about 75k equivalent logic gates and the processing capability is up to 90Mbps. [ABSTRACT FROM AUTHOR]

In this paper, we present the architecture of the interactive terrestrial digital multimedia broadcasting (T- DMB) system using the code division multiple access (CDMA) network for the new interactive broadcasting services. We also propose the novel structure of the novel platform based on Wireless Internet Platform for Interoperability (WIPI), which is the standard specifications for the mobile platform in Korea, to co-operate broadcasting and telecommunication. The proposed extended WIPI platform is implemented as an emulator on PC, and an integrated browser which shows multimedia broadcasting data including A V contents and interactive data returned through the telecommunication network, is developed to carry on with it. And then to verify the proposed platform and the interactive mobile broadcasting services, we implemented the integrated receiver as well as the data broadcasting server and the return channel server. Users can get interactive services or more information about broadcasting contents through CDMA network by using the proposed platform. This shows a possibility of new interactive services in digital broadcasting by using mobility of T-DMB and CDMA. [ABSTRACT FROM AUTHOR]

In this paper, we present a single-chip receiver for DVB data broadcasting system, which is designed using the methodology of hardware and software co-design. The hardware part filters out and descrambles the necessary MPEG-2 Transport Stream (TS) packets, then sends them to PC. Some useful peripheral functions such as PCI interface, I²C bus controller and smart card 7816 interface are also developed to provide a cost-effective solution. Meanwhile, multi-protocol decapsulation related to data broadcasting protocol is analyzed and implemented mainly by software. In order to improve the throughput and hardware utilization, we adopt chaining mode direct memory access (DMA) scheme and a double buffer approach both in hardware and in software. Moreover, the parameters of chaining mode DMA and the depth of buffer are further optimized by theoretical analysis. The result indicates the throughput of chaining mode DMA is up to 475.8 Mb/s, which is 24 times as much as non-chaining mode DMA strategy. [ABSTRACT FROM AUTHOR]

For video broadcasting, the harmonic scheme has been reported to have the best performance for the user's waiting time. However, it does not always provide the video data to the users in time. This drawback has been overcome in the cautious harmonic scheme, which is easy to implement, though it requires more bandwidth. The bandwidth is assigned to a video based on its popularity, i.e., for a more popular video, a large amount of bandwidth is required. The popularity of the video changes over a period of time. Therefore, for using the bandwidth efficiently, its allocation to a video should also be adapted according to the popularity of the video, and at the same time, the user services should not get disrupted. In this paper, we propose seamless channel transition for the cautious harmonic scheme. In the proposed seamless cautious harmonic scheme, during the channel transition, the old users do not get disrupted and the new users get the same services as it is provided with the old channels. The seamless cautious harmonic scheme has much better performance for the user's waiting time than that of the seamless staircase scheme. [ABSTRACT FROM AUTHOR]

This paper proposes a DSM-CC carousel caching and management architecture that can support both priority-based scheduling of monitoring threads and caching of carousel objects for a quick launch and download of Xlet. The carousel objects are broadcast cyclically by the transmission policy. Lack of carousel object reception may cause performance deterioration. The data broadcasting middleware should guarantee real-time characteristics such as the processing time in periodic monitoring threads to detect a change in information without a long latency time. Therefore this proposed architecture can improve the predictability of periodic monitoring section filter threads by using the managing the thread pool and scheduling periodic threads. To guarantee fast launch of the data broadcasting application, this paper also proposes the cache control mechanism of DSM-CC data/object carousel. This proposed architecture can accommodate-data broadcasting middleware that uses DSM-CC object carousel mechanisms, such as ACAP, OCAP and MHP. [ABSTRACT FROM AUTHOR]

PN-sequence padding (PNP) TDS-OFDM transmission scheme has recently been proposed as an appealing alternative to the traditional Cyclic Prefix (CP) OFDM technology as it can provide significant improvement in the spectrum efficiency. In this paper, an iterative method is introduced to subtract the PN sequence. padding for the TDS-OFDM systems to mitigate the residual inter symbol interference (ISI) from the imperfect channel estimation, and the inherent channel estimation techniques are also performed to track the channel changes. Results show that this iterative algorithm can effectively remove the impact from the residual ISI on the slow-fading broadcast channels, even in the presence of very large channel delays in the single-frequency simulcast networks (SFN). [ABSTRACT FROM AUTHOR]

Digital video broadcasting-terrestrial (DVB-T) is an important multimedia technology capable of high data-rate transmission. Orthogonal frequency division multiplexing (OFDM) has been the backbone technique in the current DVB-T systems adopted by Europe and Japan. However, since the OFDM system is very sensitive to the frequency synchronization and phase errors, which will induce the intercarrier interference (ICI), the ongoing research has been dedicated to this ICI problem in the presence of the Doppler frequency drift and the fading channels. A means to deal with the ICI problem is called the ICI self-cancellation or polynomial cancellation coding scheme. In this paper, we establish the complete simulation environment for the physical layer of the DVB-T system and then evaluate the effectiveness of the ICI self-cancellation coding scheme compared with the existing convolutional coding scheme for different fading channels and different Doppler frequencies. According to our simulation results, we conclude that the ICI self-cancellation scheme significantly outperforms the convolutional coding scheme which is adopted by the existing DVB-T standard for the AWGN and the frequency non-selective fading channels, but both schemes have the similar performance in the frequency-selective fading channels. [ABSTRACT FROM AUTHOR]

Although the Ungerboeck's TCM (Trellis Coded Modulation) is attractive in terms of high efficiency with low descending data rate by coding and high coding gain, it is difficult to implement To remove this complexity, a pragmatic approach to the TCM, which is realized by employing the defacto convolutional code (constraint length K= 7 and rate 1/2), was proposed. In this paper, a simpler realization of the TCM of rectangle type 2N QAM (N is even number; ≥ 4) by using the pragmatic approach is presented. We will show the convolutional coding and the Viterbi decoding by the decomposition from two-dimensions into each one-dimension independently. By this decomposing, it is possible to apply the pragmatic approach to minimize hardware and cost Therefore it is very useful for 64 QAM or 256 QAM applications such as digital video broadcasting over digital cable TV (ITU-T J.83) and Fixed Wireless Access (IEEE802.16) systems. It can be applied not only to single carrier QAM but also to multi-carrier QAM like OFDM. [ABSTRACT FROM AUTHOR]

MPEG-4 video streaming service is being regarded as a de facto standard service for current mobile multimedia video streaming services such as video conferencing, voice over IP, and even state-of-the-art digital multimedia broadcasting technology. There have been many illegal users who have used copyrighted material without getting permission and/or paying for its use. Therefore, much attention has been paid for Digital Rights Management (DRM) for digital media. We constructed a protection scheme for MPEG-4 video file format, which can be applied, to the video services that are exploiting the MPEG-4 standard In this protection scheme, minimum segments of every Video Object Plane in a MPEG-4 video file could be encrypted with a symmetric cryptography system like a DES (Data Encryption Standard) so that people who have not received permission and/or paid to use the contents would not be able to view them. We applied this scheme to all kinds of MPEG-4 VOP (Video Object Plane) types, that is I-, P-, and B-VOPs respectively. The prototype system was developed for proofing the feasibility of this scheme for hand-held devices and for mobile multimedia service environment. The efficiency of this scheme is reported at the end of this paper. [ABSTRACT FROM AUTHOR]

This paper introduces T-DMB transmission system in Korea based on Eureka-147 DAB and presents a new architecture of transmission system for digital multimedia services. For transmission of the digital multimedia contents in mobile environment by using the existing DAB, we developed a T-DMB processor which performs T-DMB encoding and insertion of the media stream into the existing DAB transmission system. After the implemented T-DMB processor can be connected to the front of the commercial Eureka-147 DAB system, and the performance of the T-DMB system is confirmed through the T-DMB experimental broadcasting in Korea. [ABSTRACT FROM AUTHOR]

The harmonic data broadcasting scheme provides the best user latency. However, it has a drawback of not providing the video data always in time to view. This drawback has been overcome in some schemes. These schemes share common organizational structure to the harmonic scheme and hence may be called its variants. The main variants include cautious, quasi-harmonic, and polyharmonic schemes. The polyharmonic scheme has better performance for user latency in comparison to the cautious and quasi-harmonic schemes. But this scheme works by constraining a user for a fixed delay after receiving his/her request During that delay period, some appropriate portion of the video data is stored in the buffer storage at the client's site and it can be read from the buffer, whenever it is needed. In the polyharmonic scheme, two main parameters constrain its practicability. First, it needs the videos to be divided into the large number of subsegments that increases complexity of management Second, it requires huge amount of storage space at the client's site, increasing thus the cost of the end system. In this paper, the partially prestored harmonic scheme has been proposed, which requires less storage space than the polyharmonic scheme without affecting the user waiting time. Further, the number of subsegments of the video is considerably less, while maintaining the same user latency. [ABSTRACT FROM AUTHOR]

Conditional Access System (CAS) is one of the key techniques in digital television (DTV) broadcast which is used to charge the subscriber for subscribing fee by scrambling the program information. Scrambling algorithm and key distribution are the most important parts for CAS. In this paper, we proposed a new key distribution scheme based on hierarchical access control for conditional access system in digital television broadcast. Our key distribution scheme can greatly reduce the encrypting computation and acquire higher efficiency and security. Moreover, the proposed scheme is more flexible in processing joining and leaving of subscriber, which is very important for service provider to manage the subscriber. [ABSTRACT FROM AUTHOR]

In this paper we analyze the decoding performance of Raptor codes in Broadcast/Multicast delivery systems. Based on the extensive analysis of the statistics of the behavior of the Raptor codes, we introduce an efficient decoding strategy targeting real time applications on embedded systems. Further, we propose a new efficient incremental decoding algorithm. We show that the proposed algorithm performs up to 42% better than the existing algorithm, when implemented in software on an embedded system platform. We also show that when implemented on a dedicated hardware, the proposed algorithm is 19 times better than its software version in terms of throughput and energy consumption. [ABSTRACT FROM AUTHOR]

This paper describes the receiver design of active phased array antenna (APAA) for mobile broadcasting and communications service via satellite. This system was optimally designed with RX-channels on the consideration of minimum size and cost besides electric performances. A dual-band and dual-polarized microstrip 8 ..4 array antenna was designed as a radiator. This antenna had high directivity and wide impedance bandwidth with dual-feeding structures such as the microstrip direct feeding for Band1 and the aperture coupled strip-line feeding structure for Band2. For system minimization, active channel blocks (ACBs) playing the role for signal amplification and phase control were directly combined behind the radiators with band pass filters (BPF). A beam-forming module was designed by 10:4 channel combining structure. Thus, the satellite signal power received from 10 radiators was combined into 4 channels for satellite auto tracking and signal demodulation on vehicles. Finally, to confirm the normal operations of the system, the outdoor communications test in a satellite communication environment was accomplished by the main terminal that provided satellite Internet service. [ABSTRACT FROM AUTHOR]

In time-domain synchronous (TDS) block transmission systems, known symbols are padded in the guard interval between data blocks using some specific patterns. The complexity of channel estimation is relatively high for the time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) system. As a result, original TDS-OFDM is only used for downlink broadcasting. This paper proposes a new frame structure based on TDS block transmission. The proposed frame structure can simplify the channel estimation and support the multiuser scenarios, due to the proposed padding sequence and its specific time and frequency allocation pattern. It supports the variable number of frames in one superframe, which provides the flexibility to combat various channel conditions and maintains the system efficiency. Because of these characters, it can be used in wireless uplink channel as an alternative orthogonal frequency division multiple access (OFDMA) structure. Simulation results show that the performance of the proposed frame structure is almost the same as the conventional OFDMA scheme, but has better spectrum efficiency. Therefore, it is preferred to be used in the return channel of terrestrial broadcasting systems. [ABSTRACT FROM AUTHOR]

In the advanced generalized conservative staircase (AGCS) method, the video segments are arranged in groups. The first group contains first segment, second group contains next two segments, and pth group (p>2) contains 3ª2P-3 number of segments starting with kth segment S,. where k=3ª2p-3+1. Each segment of pth group (p>2) is divided into 3ª2P-3ª+mp+mp-1 subsegments, where mp determines the number of subsegments of a segment in pth group that are transmitted in a time slot. The subsegments are arranged in nip disjoint sets. The first set consists of subsegments Sq+i,2,..., Sq+i,q, Sq+i,q, where q 3ª2P-3 1⩽i⩽q, and zth set (1p) consists of subsegments Sq+i,qª(z-1)+z-1, Sq+i,qª(z-1)+z+1 Sq+i,qªz+z-1. In the AGCS method, an upper bound on mp has been derived to provide continuous data. If larger value of mp than its upper bound is taken, then the method will not provide continuous data. But, increasing the value of mp decreases the bandwidth requirement, which in turn gives better method. In this paper, we discuss a scheme that removes the bound on mp and still provides the continuous video data to users. [ABSTRACT FROM AUTHOR]

In order to deliver video streams efficiently over WiFi to many thousands of consumer handheld devices, broadcast protocols must be employed. In this mode of operation the received video quality can deteriorate rapidly as a result of high application layer packet loss which occurs because MAC frame retransmission cannot be used. In this paper we develop a robust video delivery solution for broadcast transmission over 802.11a/g. Using a cross-layer WiFi simulator in combination with an accurate time-correlated fading channel the received video quality is evaluated for broadcast H.264 video sequences. Application layer cross-packet forward error correction is then used together with error concealment at the video client. Furthermore, the application of an external packet interleaver is considered. Combining a block size of two hundred packets (which introduces a 4.8 second delay) and an application layer FEC code rate of 0.75 our results demonstrate that video can be successfully broadcast over WiFi to many thousands of handheld terminals at large-scale spectator events. [ABSTRACT FROM AUTHOR]

This paper aims to combine adaptive modulation and coding with layered video coding to improve the quality of video services to users experiencing differing radio conditions, in the context of broadcast and multicast standards such as MBMS and BCMCS. We propose an optimal radio resource allocation algorithm which maximizes a general performance metric for a video session in polynomial time. We show that system-wide optimal resource allocation can be obtained by combining our algorithm with a simple two-step decomposition of the system. In some configurations frequent re-allocations of resource are required, so we also present a sub-optimal allocation algorithm which runs in near linear time. Simulation results show better video quality than existing resource allocation schemes over a range of conditions, and also suggest that the difference between the performance of optimal and sub-optimal solutions is less than 3%. [ABSTRACT FROM AUTHOR]

OFDMA is regarded as a promising solution for improving the performance of interactive wireless broadcasting systems. Recently, to enhance the performance of OFDMA systems, MIMO techniques have been investigated, and the OFDMA systems have been extended to MIMO architectures. Although transmit diversity is clearly advantageous on OFDMA uplink system in interactive broadcasting, it may not be possible that practical OFDMA system of wireless interactive broadcasting have more than two antennas due to size, cost, or hardware limitations. Cooperative diversity techniques are proposed to overcome the limitations. Cooperative networks aim to utilize the available terminals as a collection of distributed antennas for the transmission of signals from one end of the network to the other. Therefore, this paper focuses on design and performance evaluation of MIMO-OFDMA uplink system with cooperative diversity for wireless interactive broadcasting. For high-rate and reliable transmission, efficient transmission codes are proposed for two transmission cases (one-sided transmission case and two-sided transmission case). And, we present our investigations of the effects of line-of-sight. In the wireless communication environment, line-of-sight is very important to improve the system performance. Under the condition of utilizing the line-of-sight of cooperative partner, the performance of a terminal without line-of-sight can be improved. Taking into account the effects of utilizing line-of-sight of cooperative partner, the BER performance is investigated for a MIMO-OFDMA uplink scenario. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present the concept for the development of an entirely speech-based user interface for a digital radio in combination with the possibility to specifically search for audio and data content. On the basis of a Digital Audio Broadcasting DAB device the embedded system utilizes a multichannel receiver with the possibility of simultaneously monitoring a variety of information sources with the purpose to generate spoken replies to verbal user requests. Furthermore, the system embraces an audio repository storing speech-based content elements to diminish the volatile property of broadcast content and to enable a memory function.' [ABSTRACT FROM AUTHOR]

This paper describes a highly efficient transmission system for digital broadcasting redistribution services using IPTV technique. For basic requirements of IF redistribution services, we propose highly efficient compression scheme, SI (Service Information) multicasting scheme and a robust IF transmission scheme. A prototype system is implemented based on the proposed scheme, and its performance is evaluated. [ABSTRACT FROM AUTHOR]

Digital Multimedia Broadcasting (DMB) is one of burgeoning communication technologies, which can provide audio, video, and data services to mobile terminals using broadcasting infrastructures. Data services in Terrestrial—Digital Multimedia Broadcasting (T-DMB) inherently have the disadvantage of retransmitting a lot of data unnecessarily for reliability. This paper proposes a novel optimized transmission policy using segment size and repetition number variability, which maximizes the object-level throughput as well as improves reliability. The theoretical modeling and simulation results demonstrate that our policy provides a throughput gain over the conventional protocol. [ABSTRACT FROM AUTHOR]

This paper presents an investigation into improving the channel estimation scheme and reducing the effects of symbol timing misalignment when the Digital Video Broadcasting-Return Channel through Terrestrial (D VB-RCT) is used as return path model. Under Orthogonal Frequency Division Multiple Access (OFDMA) which uses the modulation scheme of DVB-RCT, appropriate symbol length of Constant-Amplitude Zero-Autocorrelation (CAZAC) sequences as a preamble could be utilized in accordance with the number of transmitting antenna and channel condition. However, because its capability of channel estimation is limited by the number of transmitting antennas and multipath components to maintain the orthogonality, we propose more flexible preamble design called extended-GAZAC (E-CAZAC). Also, taking into account the effect of multiple access interference (MAI) introduced by a symbol timing misalignment, the bit error rate (BER) and throughput performance are investigated for a typical OFDMA uplink scenario. [ABSTRACT FROM AUTHOR]

Digital multimedia broadcasting (DMB) is a reliable multi-service system for mobile and portable receivers. DMB system allows interference-free reception under the conditions of multipath propagation and transmission errors using coded orthogonal frequency division multiplexing modulation (COFDM) and unequal error protection (UEP) scheme. For error correction of portable DMB receivers, punctured convolutional code and viterbi decoder is developed but it needs lots of computations for real-time operation. So, it is desired to design a high speed and low-power hardware scheme for viterbi decoder. This paper proposes a combined add-compare-select (ACS) and path metric normalization (PMN) unit using pre-computation technique for DMB system. The proposed PMN unit reduces the critical path by applying fixed value selection algorithm using the comparison tree properties. We also propose an ACS structure using the decomposition and pre-computation technique for reducing the complexity of the adder, comparator and multiplexer. Simulation results shows that area, gate delay and power consumption are reduced about 3.78 %, 23.80 %, and 12.22 %, respectively. [ABSTRACT FROM AUTHOR]

This paper presents an Interactive Terrestrial Digital Multimedia Broadcasting (T-DMB) Player. Interactive T-DMB contents consist of the main AV streams and additional data streams such as BIFS (Binary Format for Scene) streams, OD streams, and image streams. In order to properly play interactive T-DMB contents, presented player includes BIFS Decoder, BIFS Manager and JPEG Decoder modules. The implementation of the interactive player and its capabilities are presented along with usage examples. [ABSTRACT FROM AUTHOR]

Data Broadcasting service is an essential part of the digital broadcasting and provides diverse services by exploiting underlying digital transmission technology. Thus various middleware standards for data broadcasting have been established by international organizations such as MHP of DVB, DASE and ACAP of ATSC and BML of ARIB. On the other hand, these multiple incompatible middlewares result in complicated problems, i.e. extra cost for redundant application development, duplicated middleware implementation and interchange problem of data contents over different middleware specifications. By suggesting one of a solution to this engineering problem, this paper proposes an integrated data broadcasting architecture based on the component-based approach. Through the precise comparison and analysis of each middleware standards, we identifying the characteristics of each middleware and integrate the core component of data broadcasting in the design, thus our architecture can be flexibly compatible with various standards. We expect that this integration can solve the preceding problems by the proposed architecture. [ABSTRACT FROM AUTHOR]

The staircase broadcasting scheme has optimal performance for the buffer storage and the disk transfer rate. However, this scheme sometime fails to provide the video data to the users in time. This limitation has been overcome in the conservative staircase scheme developed recently. In this scheme, the video segments are downloaded and stored at the client's site in their entirely before they are required for viewing. It does overcome the non-delivery of the video data to the users in time, but at the cost of extra resources. In this paper, we propose a new scheme named as generalized conservative staircase scheme, which requires less amount of resources and does not suffer from the problem of non-delivery of video data. The proposed scheme requires less amount of bandwidth by downloading the video data at slower rate. Thus this scheme has better performance for the viewer's waiting time and requires less amount of buffer storage and the disk transfer rate as compared to the conservative staircase scheme. [ABSTRACT FROM AUTHOR]

This paper presents a new economic and effective TPEG (transport protocol experts group) application for location based service (LBS) that can be provided in terrestrial-digital multimedia broadcasting (T-DMB) transmission system. We propose a novel point-of-interest (POI) application interoperable with TPEG protocol, and introduce the POI data server/client and the DMB receiver with TPEG decoder implemented by using the proposed protocol. The stability and effectiveness of the proposed protocol is verified through the experimental broadcasting, and the pilot service using the commercial T-DMB network is being provided successfully. [ABSTRACT FROM AUTHOR]

Nowadays, the progression of digital broadcasting has been toward establishing a user-friendly TV watching environment through personalized broadcasting services. In the consumer domain, video content filtering enables personalized broadcasting service in which a TV viewer obtains desired scenes even from live broadcasts which can not possess metadata. In this paper, therefore, we propose a new real-time content filtering system for live broadcasts which can be applied to TV terminals such as the set-top box and personal video recorder. Based on the proposed filtering, the TV viewer can watch not only favorite broadcasts of a main channel, but also get desired scenes from live broadcasts of other channels simultaneously. The usefulness of the proposed broadcasting content filtering is verified with sport videos on a test-bed broadcasting system. [ABSTRACT FROM AUTHOR]