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Broadcasting, IEEE Transactions on

Issue 2 • Date Jun 1993

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Displaying Results 1 - 8 of 8
  • Performance of π/4 SQAM in a hard-limited channel in the presence of AWGN

    Publication Year: 1993 , Page(s): 301 - 306
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (420 KB)  

    A strategy that reduces the spectral spreading when an ideal hard-limiter is used as a first approximation to a fully saturated power amplifier is presented. This strategy combines superposed quadrature amplitude modulation (SQAM) filtering with the π/4-shift quadrature phase-shift keying (QPSK) digital transmission format adopted for the first generation of US digital cellular systems. Simulation results showed that this π/4 SQAM filtering strategy increased capacity by 35% in comparison to hard-limited π/4 QPSK. Using computer-aided design, a receive filter that would limit the degradation of E b/N0 to less than 1.4 dB at a bit error rate of Pe=10-4 was selected View full abstract»

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  • F-QPSK-a superior modulation technique for mobile and personal communications

    Publication Year: 1993 , Page(s): 288 - 294
    Cited by:  Papers (26)  |  Patents (17)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (464 KB)  

    A brief review of the principles and properties of F-QPSK (quadrature phase shift keying) modulation is given. Its spectral efficiency is compared with that of Gaussian minimum-shift keying (GMSK) using adjacent channel interference (ACI) as a parameter. It is established that in a noncellular environment, hardlimited F-QPSK has a spectral efficiency of 1.42 b/s/Hz, which is up to 51% more spectrally efficient than GMSK BT=0.5 for ACI=20 dB. F-QPSK's BER performance in AWGN and Rayleigh fading channels is shown to be superior to that of GMSK. The spectral efficiency of the modulations in cellular/microcellular environments where frequency is reused in geographically separate cells to achieve higher capacity is compared. It is shown that the application of F-QPSK in such environment would leads to a 95% increase of system capacity compared to GMSK. It is concluded that the power and spectrally efficient F-QPSK make it an excellent candidate for future high-capacity personal communication system (PCS) networks View full abstract»

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  • Measuring peak/average power ratio of the Zenith/AT&T DSC-HDTV signal with a vector signal analyzer

    Publication Year: 1993 , Page(s): 255 - 264
    Cited by:  Papers (3)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (828 KB)  

    The different power measurement techniques used for NTSC (peak envelope power) and HDTV (average power and peak-to-average power ratio) are described. A brief description of a digital data transmission system is included to show why the HDTV signal is noiselike in nature and how it can be measured. A new type of RF analyzer with the ability to statistically measure peak-to-average power ratio is presented. The Zenith/AT&T digital spectrum compatible high definition television (DSC-HDTV) data transmission system is currently one of the systems being evaluated for the consideration as a US broadcast standard. Examples of signal measurement for this system are provided View full abstract»

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  • Pilot tone aided coherent GMSK systems for sound/data mobile broadcasting

    Publication Year: 1993 , Page(s): 295 - 300
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (404 KB)  

    A Gaussian minimum-shift keying (GMSK) modem with built-in fade canceler is proposed narrowband mobile digital broadcasting systems. The proposed scheme combines DC suppressing line code and high-pass filters to create a spectral null at the carrier frequency of the transmit GMSK signal spectrum. This enables an unmodulated carrier pilot tone to be transmitted with the digital broadcast signal without mutual interference. In the receiver, the recovered pilot is used to coherently demodulate the received signal without phase ambiguity. The pilot can be also be used to track and cancel out the random phase noise induced by fast fading. The scheme is applied to a 16 kb/s BT=0.25 GMSK signal with Bv=800 Hz, and its performance over a fast Rayleigh fading channel is investigated using computer simulation. The results demonstrates that the proposed coherent modem is capable of significantly outperforming conventional differential detection in fast fading environments such as a broadcasting channel for mobile reception View full abstract»

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  • Switching considerations to combat spectral pollution in TDMA for satellite broadcasting

    Publication Year: 1993 , Page(s): 282 - 287
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (292 KB)  

    A better switching technique for combating spectral pollution i.e. spectral spreading of burst time-division multiple access (TDMA) digital FM and π/4-QPSK (quadrature phase-shift keying) systems, is proposed. The effects of rectangular, linear, and raised cosine ramp on/off switching are examined for two prototypes using both hardware experimental methods and computer simulation for different gating rates, duty cycles, roll-off factors of transmitter filter and ramp on/off times. The measures results agree with the computer simulation results and indicate that the adjacent channel interference (ACI) caused by the burst operating in TDMA π/4-QPSK is significantly reduced by raised cosine switching in comparison with other types of switching View full abstract»

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  • A new 8-14 channel coding for D-3 format VTR

    Publication Year: 1993 , Page(s): 265 - 272
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (568 KB)  

    An 8-14 channel coding method suitable for high density recording for digital VTRs was developed. Using this coding, an 8-b data word is transformed into 14-b code word, assuming that the distance between magnetic polarity transitions is two to seven channel bits, the maximum absolute of the DSV (digital sum variation) is seven. The code has a minimum recorded wavelength 14% longer and a required bandwidth 12.5% narrower than those of S-NRZ and M2 codes. Since it is a run-length-limited block code, it provides simplified recording and reproduction equalization, azimuth and overwrite recording, no error propagation to any other word, and error detection. The signals encoded by applying this method as well as S-NRZ and M2 to 64-Mb/s M-sequence data were recorded and reproduced using metal particle tape and a Sendust laminated sputtered type head. The results show that the reproduced SNR of 8-14 channel coding was 2.8 dB higher than those of S-NRZ and M2 View full abstract»

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  • Using elevated radials in conjunction with deteriorated buried-radial ground systems

    Publication Year: 1993 , Page(s): 249 - 254
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (364 KB)  

    Computer-modeling exercises performed indicate that it is possible to add a group of four elevated radials to a pre-existing conventional AM-broadcast vertical monopole antenna system in order to restore performance to its original level (or better) in situations where the buried-radial ground system has been damaged. A wide variety of different configurations for the elevated radials are examined, including variations in orientation, length, and height above ground. It is stressed that extensive outdoor testing should be performed in order to verify these computer predictions. The computer software used is the Numerical Electromagnetics Code View full abstract»

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  • Pattern synthesis with a feed network consisting of lossy transmission line sections

    Publication Year: 1993 , Page(s): 273 - 281
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (488 KB)  

    A method for feeding the elements of an antenna array with a lossy transmission line section is presented. Four examples showing the applicability of the method are given. The behavior of the system in a frequency band around the design frequency is studied. Besides changes of physical length, changes in the frequency bandwidth of the antennas are observed 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