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Broadcasting, IEEE Transactions on

Issue 3 • Date Sept. 2001

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Displaying Results 1 - 13 of 13
  • Commentary - planning factors redux

    Publication Year: 2001
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (6 KB)  

    The concept of planning factors for the Grade A and Grade B service contours for the current analog NTSC television service, described in this paper, were also employed for the establishment of the service parameters developed by the FCC's Advisory Committee on Advanced Television Service (ACATS). There were, of course, several significant differences in the parameters adopted. Because of the perceived "all or nothing" nature of digital signal reception it was decided that only a single service contour would be adopted,-the noise limited contour (NLC)-roughly comparable to the Grade B contour. Also, the new DTV station service areas were designed to "replicate" the existing station's Grade B service with service within the NLC to be determined using the Longley-Rice propagation model. Planning factors are essential in developing a national channel allotment plan for a television service. The factors are, of course, based on location and time statistical distributions and typical home receiving systems. Reception at any specific location may vary from these assumptions, as was the case for NTSC service, which also will be true for the new DTV service. View full abstract»

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  • Multicast routing strategies for zoned VP-based ATM networks

    Publication Year: 2001 , Page(s): 240 - 248
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (514 KB) |  | HTML iconHTML  

    In ATM networks, the concept of virtual path (VP) greatly simplifies cell processing in switches. The virtual channel connection (VCC) can be more quickly and efficiently established by good strategies of resource management. The method of constructing virtual path and the strategies of managing and allocating resources greatly affect the performance of the system operation. We propose a new architecture and the corresponding methods of constructing virtual paths; various methods and strategies, such as bandwidth control, rerouting, resource management, and fault recovery, are studied (Lee and Shie 2000). This paper focuses on multicast routing and analyzes some algorithms for this model. Simulation results show the good performance in bandwidth utilization, blocking probability, and loss probability View full abstract»

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  • Spatial diversity analysis for digital TV systems

    Publication Year: 2001 , Page(s): 198 - 206
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (274 KB) |  | HTML iconHTML  

    Spatial diversity for digital TV systems has been studied using the results of a measurement campaign of the radio channel complex frequency response for two different situations: an outdoor-indoor channel and an indoor-indoor channel. It is shown that the actual improvement of spatial diversity is not only the mean level increase, but the reduction of both the level crossing rate (LCR) and the average fade duration (AFD). The mean level gain is in the range 1.2-3 dB for the indoor-indoor channel and within 1.4-2.9 dB for the outdoor-indoor channel and the LCR/AFD improvement is between 9.5 and 15 dB for both environments. To explain the behavior of the diversity system, high resolution angle of arrival and delay information was obtained. It is concluded that it is the interference of the direct propagation path with the main reflections that causes the received field to follow a standing wave pattern and shapes the spatial diversity gain behavior View full abstract»

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  • Reradiation (echo) analysis of a tapered tower section supporting a side-mounted DTV broadcast antenna and the corresponding azimuth pattern

    Publication Year: 2001 , Page(s): 249 - 258
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (445 KB)  

    Reradiation from a non-vertical obstruction such as a tapered section of a broadcast antenna supporting tower is analyzed. The reradiation takes on the form of a cone, which is symmetrical about the tower leg axis, modified by the reflection coefficient that varies with azimuth. The reradiation is directed either above the horizon where it is lost or below the horizon where it interferes as an echo with the direct radiation. The reradiation has an elevation pattern which is a replica of the transmitting antenna elevation pattern, but is redirected by the nonvertical tower leg. The reradiation combines with the direct radiation to form an azimuth pattern which varies with distance from the broadcast antenna. The reradiation, being an echo, is analyzed for multipath distortion of the VSB pulse. It is shown that the impact on DTV receiver threshold is minimal View full abstract»

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  • DTV coverage and service prediction, measurement and performance indices

    Publication Year: 2001 , Page(s): 207 - 217
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (346 KB) |  | HTML iconHTML  

    It is now clear that methods used to predict the replication of the NTSC service in the United States were idealized and, for the most part, not validated. The need to review the methods and procedures now in use is highlighted by the various field tests conducted in the U.S. and elsewhere. This paper outlines potential improvements in the modeling, methods and procedures now in use for prediction and measurement of the DTV service View full abstract»

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  • 60 GHz band 64 QAM/OFDM terrestrial digital broadcasting signal transmission by using millimeter-wave self-heterodyne system

    Publication Year: 2001 , Page(s): 218 - 227
    Cited by:  Papers (9)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (443 KB) |  | HTML iconHTML  

    This paper describes the first time experimental studies on 60-GHz band transmissions of terrestrial digital broadcasting signals (ISDB-T) with 64-QAM modulations on coded orthogonal frequency division multiplexing (COFDM) format. It has been a very difficult experiment to accomplish because it requires very stable and low phase-noise oscillators in the millimeter-wave band. The use of our proposed millimeter-wave self-heterodyne system, overcame this problem without using a stable oscillator, and provided a bit error rate (BER) of less than 10-6 without any forward error correction. We also discuss the relationship between the carrier-to-noise power ratio and the BER obtained, and demonstrate that the penalty of the required CNR for our experimental system is less than 1 dB compared to the results of a back-to-back BER test View full abstract»

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  • Understanding television's grade A and grade B service contours

    Publication Year: 2001 , Page(s): 309 - 314
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (164 KB) |  | HTML iconHTML  

    The Grade A and Grade B service contours of a television broadcast station are used for a host of administrative purposes by the FCC including the regulation of CATV systems. Additionally, the contours are used by most stations for promotional and marketing purposes. The numerical values associated with these contours represent levels of field strength; consequently, assumptions were made in their determination as to noise limitation, the antenna gain, and transmission-line loss of the receiving system. Also, consideration was given to the subjective nature of the picture quality and the statistical variation of the field strength with time and location. The nature of these variables is discussed and the assumed values are tabulated in a format suitable for easy understanding and for analysis of possible future changes View full abstract»

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  • A method to determine the detuning reactance for unused elements in directional arrays

    Publication Year: 2001 , Page(s): 259 - 262
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (73 KB) |  | HTML iconHTML  

    This paper provides insight into the basics of radiation from unused elements in MF broadcast directional arrays. It then sets forth the criteria for suppressing that radiation and suggests a method for meeting those criteria. Component values are determined by post processing the NEC output file. Numerical examples demonstrate both the simple and complex cases. Some limitations to practical applications are identified and areas for further study are mentioned View full abstract»

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  • BER computation of 4/M-QAM hierarchical constellations

    Publication Year: 2001 , Page(s): 228 - 239
    Cited by:  Papers (42)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (341 KB) |  | HTML iconHTML  

    Hierarchical constellations offer a different degree of protection to the transmitted messages according to their relative importance. As such they found interesting application in digital video broadcasting systems as well as wireless multimedia services. Although a great deal of attention has been devoted in the literature to the study of the bit error rate (BER) performance of uniform quadrature amplitude modulation (QAM) constellations, very few results were published on the BER performance of hierarchical QAM constellations. Indeed the only available expressions "leading-term" approximate BER expressions for 4/16-QAM and 4/64-QAM. We obtain exact and generic expressions in M for the BER of the 4/M-QAM (square and rectangular) constellations over additive white Gaussian noise (AWGN) and fading channels. For the AWGN case, these expressions are in the form of a weighted sum of complementary error functions and are solely dependent on the constellation size M, the carrier-to-noise ratio, and a constellation parameter which controls the relative message importance. Because of their generic nature, these new expressions readily allow numerical evaluation for various cases of practical interest. In particular numerical results show that the leading-term approximation gives significantly optimistic BER values at low carrier-to-noise ratio (CNR) in particular over Rayleigh fading channels but is quite accurate in the high CNR region View full abstract»

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  • Adjacent and co-channel interference from direct sequence spread spectrum systems on analog PAL

    Publication Year: 2001 , Page(s): 297 - 307
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (402 KB) |  | HTML iconHTML  

    This paper presents extensive results of a laboratory test held to examine the conditions under which analog PAL-G and spread spectrum systems can share spectrum. RF TV protection ratios for adjacent and co-channel spread spectrum interference are derived. For the PAL signal two different received levels, giving undistorted baseband SNR 42 and 37 dB respectively, are examined. Different spread spectrum RF bandwidths and carrier frequency offsets between the analog and digital signal are also included in the experiments. Results for all possible interference conditions and cases are presented in tables and 3-D charts View full abstract»

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  • Using elevated radials with grounded towers

    Publication Year: 2001 , Page(s): 292 - 296
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (97 KB) |  | HTML iconHTML  

    This paper describes a technique in which elevated horizontal radials are used in combination with a grounded quarter-wave tower to construct an AM-broadcast transmit antenna. Computer analysis indicates that the radiation efficiency of these antennas can be within one decibel of that of a conventional base-insulated 1/4-wave tower with an extensive buried-radial ground system View full abstract»

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  • MF AM antenna radiation pattern verification method by near field measurements

    Publication Year: 2001 , Page(s): 285 - 291
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (335 KB) |  | HTML iconHTML  

    No other component of a broadcast system offers as many options in terms of performance and efficiency as the antenna system. The radiation pattern of a MF (medium frequency) antenna is one of the major characteristics to describe the performance of the system. To optimize the reach and effectiveness of broadcast antennas and to prove regulatory compliance it is essential to know their radiation pattern for a given operating environment. Consequently it is of great interest for the broadcaster to verify the specified patterns on the installed antenna system. A tried and trusted method is to fly a helicopter or a plane carrying special recording equipment to perform far field measurements over the site. Besides being costly, this is not always possible. In this article, ground based methods where the calculated radiation patterns are verified by near field measurements are presented. This method provides good results with less expenditure compared to the above mentioned airborne far field measurements View full abstract»

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  • Short medium frequency AM antennas

    Publication Year: 2001 , Page(s): 263 - 284
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (768 KB) |  | HTML iconHTML  

    Short antennas have again attracted broadcaster attention. These kinds of antennas have been used since the 1920s. At that time it was the logical antenna as a new application of this service after more than twenty years of telegraphic transmissions. Telegraphic transmissions were the most important radio communication service at that time, and because of the long range needed the lowest frequencies as possible were employed. For this reason very short antennas were used even if their size was enormous. Top loaded monopoles were very popular and this technique was employed for broadcast use before the vertical transmitting mast exhaustive study was carried on in the thirties. Nowadays a short antenna would be useful for low power applications and specially to be mounted on building tops. Of course this kind of antennas is not intended to replace the optimum monopoles or vertical dipole where maximum efficiency, maximum gain and antifading properties were achieved after exhaustive studies and after long experience theoretically and practically achieved. CFAs, short monopoles, short dipoles and short folded monopoles have been analyzed from the theoretical and practical point of view in order to choose the simplest and most efficient. model to fulfill downtown stringent requirements View full abstract»

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Aims & Scope

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

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Editor-in-Chief
Yiyan Wu
Communications Research Ctr Canada