By Topic

Broadcasting, IEEE Transactions on

Issue 4 • Date Dec. 1998

Filter Results

Displaying Results 1 - 22 of 22
  • 1998 Index IEEE Transactions on Broadcasting Vol. 44 - Author Index

    Page(s): 553 - 555
    Save to Project icon | Request Permissions | PDF file iconPDF (367 KB)  
    Freely Available from IEEE
  • Subject index

    Page(s): 557 - 562
    Save to Project icon | Request Permissions | PDF file iconPDF (649 KB)  
    Freely Available from IEEE
  • Increasing channel capacity and range on urban optical analog AM-VSB CATV systems

    Page(s): 436 - 444
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (780 KB)  

    It is often desirable to increase the capacity and the covered distance in lightwave TV systems. For doing so, the conventional CATV channel set-usually placed within the 50 to 550 MHz frequency range-may be up-shifted, by means of a subcarrier, to a low microwave frequency range, typically located at 2 GHz. Next, this shifted spectrum directly modulates a laser diode, in the analog AM mode. It is shown that this up-shift procedure may dislodge a number of nonlinear distortion components from the useful TV band. Consequently, the system effective optical modulation index may be increased, allowing for an expansion in the channel capacity or covered distance. This enlarged capacity or distance may compensate for the modest price increase concerning the up-shift equipment. All the performance evaluations presented here were carried out with a rigorous numerical model, and assuming the lightwave systems used the economical AM-VSB format View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A PFD trigger threshold for the co-ordination of BSS(S) and point-to-multipoint terrestrial systems

    Page(s): 449 - 454
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (528 KB)  

    The International Telecommunications Union (ITU) has allocated the frequency band 1452-1492 MHz to the Broadcast Satellite Service Sound, BSS(S), on a shared basis with existing terrestrial services. In order to cover the largest possible area, the BSS(S) providers require as high a power flux density (PFD) as possible. The terrestrial fixed service on the other hand requires a level below which harmful interference will not be caused. A particularly sensitive terrestrial system is the point-to-multipoint digital radio concentrator system (DRCS) used in Australia and many other parts of the world to service rural and remote areas. A probabalistic method for the determination of a PFD trigger threshold is presented along with a recommended PFD trigger level for the co-ordination of the BSS(S) with terrestrial DRCS View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal real-time admission control algorithms for the video-on-demand (VOD) service

    Page(s): 402 - 408
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (696 KB)  

    In order to meet the quality-of-service (QOS) requirements of the VOD (video-on-demand) service, and, on the other hand, to maximize the system throughput (revenue), it is essential that the admission control algorithm be carefully designed. Two new types of admission control schemes for the VOD service are proposed. They are the enhanced strict admission control (ESAC) and the probabilistic admission control (PAC). In the ESAC schemes, we propose to use more statistics (of small amount and easily pre-calculated) than the peak frame size of the stored video information to strictly guarantee the QOS requirement and to achieve potentially much higher throughput. In the PAC schemes, we propose to use similar statistics as used in the ESAC schemes to achieve even higher throughput at the cost of some small and controllable likelihood of lost/overdue data. The admission control problems are formulated as feasibility problems where different systems of simultaneous equations are considered. For each admission control scheme, if the corresponding system of simultaneous equations has a feasible solution, then admit the call request; otherwise, reject the call. Special structures of the systems are identified so as to facilitate the development of optimal real-time admission control algorithms. Efficient optimal algorithms are also proposed to calculate the minimal buffer requirement for a given performance objective View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Video camera system using liquid-crystal polarizing filter to reduce reflected light

    Page(s): 419 - 426
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1464 KB)  

    We have been developed a video camera system using an electrically-controllable liquid crystal polarizing filter for television program production, which can quickly reduce undesirable reflected light from a window pane or watery surface, by automatically judging the polarization state of incident light from the change in video signal intensity. More than 80% of linearly-polarized incident light is removable by this method for all incident polarization angles. The time required for detecting and reducing reflected light is approximately 0.3s in our system. The drastic reduction of polarized light reflected from glass and watery surfaces was demonstrated, and object images obscured by bright reflected light were clearly captured in an instant View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A hierarchical HFC network with QoS guaranteed traffic policy

    Page(s): 517 - 526
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (892 KB)  

    The rapid growing of the Internet makes multimedia and broadband services closer to the users. For people at home, two typical networks are available to access the Internet: telephone network and CATV network. This paper presents a hierarchical tree-based structure for the hybrid fiber-cable (HFC) network where the traditional HFC network is partitioned into segments. Each segment is coordinated by a central traffic controller (CTC). A reservation-based traffic policy is also proposed for the CTC to schedule the data transmissions within the segment to provide guaranteed QoS, such as constant bit rate (CBR) service and variable bit rate (VBR) service. The CTC also furnishes the bridging function so that local traffic within the controlled segment is filtered to save the network bandwidth. Based on the segmentation concept and filtering function, the bandwidth can be reused efficiently and the system performance is improved significantly. Simulation results indicate that the proposed hierarchical HFC network performs much better than the traditional HFC network in terms of delay, delay jitter and channel utilization. Through the proposed traffic policy, the hierarchical HFC network also offers guaranteed QoS for the users View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Measurements of RF radiation near MW and SW radio broadcast stations

    Page(s): 470 - 477
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (496 KB)  

    Far field measurements of electric and magnetic fields in an area surrounding the MW and SW broadcast stations in Riyadh, Saudi Arabia are presented. Values of the electric fields contribution from each of the MW and SW stations separately are estimated. The variation of the electric field with height in a number of locations is also provided. All measured results are modeled by analytical expressions. They are then discussed and compared with the most up to date radiation safety standards. It is shown that RF radiation from strong MW and SW broadcasting stations could impose significant effects on environment outside the stations. Monitoring of the field levels for such sources should be carried out regularly View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The effect of local minima on the adjustment of complex directional arrays

    Page(s): 507 - 516
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (768 KB)  

    This paper draws an analogy between the mathematics used in linear programming and the physical process of adjusting a complex AM directional array. It reviews a mathematical definition of radiation pattern adjustment error then uses that error to relate the concept of local and global minima to the physical adjustment process. Data from an 8 tower array is used to demonstrate by example how local minima influence the outcome of the adjustment task. The data in this paper emphasize the need for an initial design that accurately predicts the array's operating parameters View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Allocation and scheduling algorithms for IEEE 802.14 and MCNS in hybrid fiber coaxial networks

    Page(s): 427 - 435
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (816 KB)  

    IEEE 802.14 and MCNS (multimedia cable network system) are two standards developed for the hybrid fiber coaxial (HFC) CATV networks. Both standards model an upstream channel as a stream of minislots. But their philosophies on resolving collisions in the shared upstream channel are rather different, where IEEE 802.14 adopts the priority+FIFO first-transmission rule and the n-ary tree retransmission rule, and MCNS adopts the binary exponential backoff algorithm with adjustable window sizes. Both provide reservation access, while IEEE 802.14 and MCNS also support isochronous access and immediate access, respectively. In this paper, we try to prepare a suggestion list for vendors on how to allocate minislots for reservation access and immediate access and how to schedule the reserved bandwidth, which greatly affect the performance of a cable network and are left open by the standards View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance analysis of Viterbi decoder using channel state information in COFDM system

    Page(s): 488 - 496
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (704 KB)  

    This paper relates to the application method of channel state information (CSI) to the Viterbi (maximum likelihood) decoder in the digital terrestrial television broadcasting system. The proposed Viterbi decoder uses the CSI derived from the pilots inserted in the transmitter of the COFDM (coded orthogonal frequency division multiplexing) system. The CSI is calculated by interpolation using the pilots in the receiver. The active real (I) and imaginary (Q) data after equalization are transferred to the branch metric calculation block that decides the euclidean distance for soft decision decoding and also the estimated CSI values are transferred to the same block. After calculating the euclidean distance for the soft decision decoding, the euclidean distance of the branch metric is multiplied by CSI. To do so, new branch metric values that consider each carrier state information are obtained. We simulated this method in Rayleigh fading defined in the ETSI standard. From the simulation, this method has better performance of about 0.15 dB to 0.7 dB and 2.2 dB to 2.9 dB in the Rayleigh channel than that of conventional soft decision Viterbi decoding with or without a bit interleaver where the constellation is QPSK, l6-QAM and 64-QAM View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Numerical calculation and statistical analysis of MW field intensity on synchronized emitters

    Page(s): 409 - 418
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (820 KB)  

    Usually, there is one MF emitter for an AM station working at one frequency in the metropolis. The authors consider three same-frequency low power AM emitters working on synchronized broadcasting. Previous field measurements in Shanghai have shown that the reception quality of three low power emitters working synchronously was rather better than a single high power emitter. This article proposes the specifications and the statistical rules of a synchronized emitter by means of computer visualization, and presents field intensity maps through calculation, and makes comparisons and analyses the results View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Digital/analogue co-channel protection ratio field measurements

    Page(s): 540 - 546
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB)  

    The digital terrestrial television standard approved by the European Telecommunications Standards Institute (ETSI) using coded orthogonal frequency division multiplexing (COFDM) facilitates the establishment of complex networks including single frequency networks (SFN) and multiple frequency networks (MFN). RTE and other partners of European Union (EU) sponsored projects such as MOTIVATE and VALIDATE have established and tested these networks in order to understand the important parameters of digital networks. Protection ratios are needed in order to plan the coverage of digital networks and minimise interference from co-channel transmitters. This paper describes a network established to field test protection ratios and details the measurements performed. Three co-channel UHF transmitters were installed at RTE mainstations in the Dublin area View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Enhancing satellite broadcasting services using multiresolution modulations

    Page(s): 497 - 506
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (912 KB)  

    In this paper we propose to take advantage of the energy link margin that can exist of satellite connections to enrich the DVB-S services with Web-like interactive services. The exploitation of such a margin is obtained by using multiresolution modulation techniques. The system architecture analysed is asymmetrical, composed of a satellite forward link and a narrowband terrestrial reverse link. ATM is adopted to support different QoS for different types of information delivered. The satellite propagation delay and the traffic and congestion control of ATM suggest to modify the slow start and the congestion avoidance of the TCP. Our approach is based on the combination of a fixed window flow control at the transport layer with the ATM traffic and congestion control. Our analysis shows that the system performance is satisfactory if some bounds of the TCP buffer size are respected and the spacing of the resource management cells is within a given range of values View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A model based approach to fault detection for the reverse path of cable television networks

    Page(s): 478 - 487
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (968 KB)  

    We present a model based method for reliably detecting faults in the reverse path of cable amplifier networks. This method has the advantage over traditional fixed-bound fault detection techniques in that it is able to accurately detect changes in signal behaviour while tracking signal changes due to environmental effects. The resulting method provides an increase in the fault detection sensitivity while simultaneously providing a decrease in the false alarm rate. We have implemented a general approach based an using a modeling engine to capture the reverse pilot signal behaviour of cable television amplifiers. Two modeling specific engines were developed for this purpose. The first one is based on the use of feedforward neural networks; the second one is based on the use of statistical analysis techniques. The resulting fault detection system, when employing either modeling engine, was able to provide good temporal localization of the onset of fault conditions along with a clear indication of the presence of the fault through its duration View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Investigations on bit error performance for video over DAB

    Page(s): 445 - 448
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB)  

    The digital audio broadcasting (DAB) system which was originally designed for high quality audio transmission to mobile receivers is investigated for transmission of compressed digital video and multimedia signals. The bit error performance is considered using various levels of error protection provided by the DAB system. As a result, a net bit rate of about 1.5 Mbit/s can be achieved. With additional error correction coding, a bit error ratio (BER) of less than 10-10 can be realized. This is the requirement for compressed video signals. The SNR per bit is below 16 dB. The results are demonstrated and compared using computer simulations of the complete system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Quality of MPEG2 signal on a simulated digital terrestrial television

    Page(s): 381 - 391
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1292 KB)  

    The monitoring of the quality of service in digital television networks needs instruments to assess automatically the perceived quality of audio and video components of an MPEG2 signal. In order to improve the knowledge of the impact of the impairments on the final service, and to validate the algorithms that will be implemented in the quality evaluation instruments, a general simulation chain has been designed and developed. This paper presents the simulations performed as well as the analysis and the synthesis of the obtained results View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal video placement for hierarchical video-on-demand systems

    Page(s): 392 - 401
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (788 KB)  

    We have been implementing a VOD system over ATM networks based on a hierarchical three-level network architecture. One of the most important design problems is how to organize video programs stored at different level of servers. In this paper, we propose an optimal video placement strategy which gives the optimal number of video copies should be stored at each level of server such that the cost function can be minimized while a lower bound of the request rejection probability for each video is guaranteed. Our major contribution is that we model the time-variant request arrivals as a non-homogeneous Poisson process View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Class-F power amplifiers with reduced conduction angles

    Page(s): 455 - 459
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (200 KB)  

    This paper determines the characteristics of class-F power amplifiers (PAs) with “class-C” conduction angles (current flow for less than half of the RF cycle). Analyses are conducted for both clipped-sinusoidal (classical class-C) and rectangular current waveforms. It is not possible to define the voltage and current waveforms arbitrarily if the production or sinking of power at the harmonic frequencies is to be avoided. As a result, only a few cases are of practical interest. In these cases, the conduction angle is set to null a specific harmonic in the current. The nulled harmonic is then used to flatten the bottom of the voltage waveform, resulting in increased efficiency and increased power output View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multipath channel characteristics using spectral analysis of the signal power density

    Page(s): 527 - 539
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (704 KB)  

    This paper introduces a concept to quantify the indirect signals in a multipath environment. By definition multipath occurs when a wave propagates to a point in space via different paths. The multipath is caused by reflection of the direct wave off objects such as buildings, towers, hills, and vehicles. A technique was developed in which the power density from a mobile receiver is recorded over time. By examination of the Fourier transform of the power density the number of indirect fields can be calculated as well as the reflection coefficient for each indirect field. The theory for this technique is developed and the limitations of the technique are noted. A few specific case studies were examined using the theory developed in this technique View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • General balance power analysis of HFHPTA with (M,N)-composite signals

    Page(s): 547 - 552
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (464 KB)  

    A general balance power analysis of HF high-power tuned amplifiers (HFHPTA) with composite drive and output signal obtained by injection of an N-harmonic signal into an M-harmonic carrier signal, is presented. M and N are positive integers where M<N and M, generally speaking, may not divide N. The valve model used in an HF amplifier is assumed to be linear. The central idea is in finding the signal parameters of an (M,N)-composite signal possessing flattened extremums. Such composite signals serve as a starting point for general balance power analysis of linear HFHPTA. It is shown that the usage of (M,N)-composite signals with flattened extremums in general balance power analysis of HFHPTA either provides almost optimal operating conditions with less than 10% error (for M<N<5) or the optimal operating conditions in all other cases View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the RLSA antenna optimum design for DBS reception

    Page(s): 460 - 469
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (916 KB)  

    An optimal design for the RLSA (radial line slot array) antenna useful for DBS reception is presented. Classical geometries and structures given in the literature are first used. It is found that in some cases these are not suitable. So, optimization techniques by using the right objective functions have been applied. Two different methods were developed and three antennas were designed. Numerical results and comparisons with other similar antennas give the advantages of our design View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

IEEE Transactions on Broadcasting covers the field of broadcast technology, including the production, distribution, transmission, and propagation aspects of broadcasting.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Yiyan Wu
Communications Research Ctr Canada