IEEE Transactions on Communications

Issue 11 • November 1973

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Displaying Results 1 - 25 of 27
  • [Front cover and table of contents]

    Publication Year: 1973, Page(s): 0
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    Freely Available from IEEE
  • Guest editorial

    Publication Year: 1973, Page(s): 1171
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    Freely Available from IEEE
  • 910 MHz Urban Mobile Radio Propagation: Multipath Characteristics in New York City

    Publication Year: 1973, Page(s):1188 - 1194
    Cited by:  Papers (89)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (951 KB)

    Small scale statistics of multipath propagation in a heavily built-up urban mobile radio environment are presented. The statistics cover vehicle travel distances on the order of 30 m along streets. Measuring equipment time delay resolution is about 0.1 μs. In some locations, paths with significant amplitudes are observed with excess delays of 9 to 10 μs. The delay spreads (sqrt{seco... View full abstract»

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  • Some Propagation Experiments Relating Foliage Loss and Diffraction Loss at X-Band and UHF Frequencies

    Publication Year: 1973, Page(s):1198 - 1206
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (675 KB)

    Measurements of signal attenuation were made from a suburban hilltop base station to a mobile vehicle on several streets in the surrounding countryside. Measurements of signal strength were simultaneously made in the winter of 1971 at frequencies of 836 MHz and 11.2 GHz and then repeated in the summer to determine the effects of foliage. The presence of foliage reduced the received signal strength... View full abstract»

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  • Baseband Performance of a Pilot Diversity System with Simulated Rayleigh Fading Signals and Co-Channel Interference

    Publication Year: 1973, Page(s):1248 - 1257
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (967 KB)

    Using simulated Rayleigh-fading FM signals, the baseband performance of a diversity system that uses a separate pilot is studied. The effect of various RF/audio bandwidth expansion ratios is included. These results show an approach to a constant asymptotic baseband SNR for large expansion ratios, with diversity increasing this asymptote by 5 dB in the case of moderate to large interference and/or ... View full abstract»

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  • Increasing Channel Occupancy in Large-Scale Mobile Radio Systems: Dynamic Channel REassignment

    Publication Year: 1973, Page(s):1302 - 1306
    Cited by:  Papers (35)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (542 KB)

    Large-scale mobile radio systems using dynamic channel REassignment switch the channels assigned to some of the calls in progress to maintain a nearly optimum separation between coverage areas simultaneously using the same channel. Dynamic channel REassignment produces a significant increase in channel occupancy. For example, in the systems studied, which have a uniform distribution of their fixed... View full abstract»

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  • [Back cover]

    Publication Year: 1973, Page(s): 0
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    Freely Available from IEEE
  • A Switched Diversity Receiving System for Mobile Radio

    Publication Year: 1973, Page(s):1269 - 1275
    Cited by:  Papers (22)  |  Patents (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    A low cost switched diversity receiving system has been developed for use in UHF-FM mobile radio. The input of a single receiver is switched back and forth between two antennas upon command from a signal level sensing logic circuit. The system has been measured on simulated Rayleigh fading channels and has been found to give a significant improvement to both voice and data signals. View full abstract»

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  • Man-Made Noise in Urban Environments and Transportation Systems: Models and Measurements

    Publication Year: 1973, Page(s):1232 - 1241
    Cited by:  Papers (91)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (952 KB)

    Analytically tractable statistical-physical models of manmade noise environments have been constructed [1]-[3]. These permit quantitative description of the various types of electromagnetic interference appearing in typical radio receivers and, in particular here, for the communication links employed in mobile transportation systems and urban environments generally. This paper presents a summary o... View full abstract»

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  • Methods for Investigation and Simulation of Mobile Data Transmission

    Publication Year: 1973, Page(s):1323 - 1324
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (176 KB)

    This paper deals with two aspects of the investigations of mobile data transmission. The first aspect shows the equipment for measuring and recording of parameters that influence the transmission. The second aspect shows the development of an analog simulation of the data transmission with the possibility of adjusting significant parameters independently. Finally the applicability of the model is ... View full abstract»

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  • The Elevation Angle of Mobile Radio Signal Arrival

    Publication Year: 1973, Page(s):1194 - 1197
    Cited by:  Papers (28)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (440 KB)

    Field measurements of mobile radio signals have shown that signal arrival is concentrated in elevation angles lower than 16°. This suggests use of an omnidirectional antenna with vertical directivity, instead of the usual whip antenna, to increase average signal strength as a further improvement in the advantages of diversity reception. View full abstract»

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  • Single-Receiver Diversity Systems

    Publication Year: 1973, Page(s):1276 - 1280
    Cited by:  Papers (5)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (536 KB)

    Diversity reception techniques can help to combat fast fading in urban areas, and this paper describes some predetection combining systems designed to be compatible with existing standard receivers. Quantitative results show that a worthwhile improvement in quality of reception can be obtained with small numbers of antennas. There are advantages to be gained if, in future receiving systems, the di... View full abstract»

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  • Traffic Engineering of Combined Mobile Telephone and Dispatch Systems

    Publication Year: 1973, Page(s):1307 - 1309
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    If a server group carrying short-holding-time queued traffic at high blocking probability is combined with another server group carrying normal blocked-calls-cleared traffic at low blocking probability, the resulting mixed group will in many cases operate at an intermediate blocking probability. Thus the mixed group provides better service to the queued traffic, while degrading the service of the ... View full abstract»

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  • Spectral and Economic Efficiencies of Land Mobile Radio Systems

    Publication Year: 1973, Page(s):1177 - 1187
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1256 KB)

    A variety of land mobile radio systems are compared by their spectral and economic efficiencies in providing various user services, system types covered are private one-channel, shared repeater one channel, controlled-access one-channel, trunked multichannel, and cellular. Spectral efficiency is defined to be the number of mobile users that can be served per MHz of spectrum in a core urban area, w... View full abstract»

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  • Statistically-Optimum Dynamic Server Assignment in Systems with Interfering Servers

    Publication Year: 1973, Page(s):1287 - 1293
    Cited by:  Papers (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (648 KB)

    Cellular mobile radio systems have been proposed that use many base stations to provide radio service over a large geographical area. In such systems, a stored-program processor assigns radio channels to base stations in real time, under certain interference constraints. The capacity and the queueing characteristics of the overall system are strongly dependent on the processor algorithms that are ... View full abstract»

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  • A Mobile Wide-Band Measurement System for Urban Man-Made Noise

    Publication Year: 1973, Page(s):1224 - 1232
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1096 KB)

    This paper describes in detail the criteria for the design of a mobile laboratory for the characterization and measurement of manmade electromagnetic noise in the urban, suburban, and rural environment. A significant difference from previous similar measurements is the bandwidth of the receiving system, which is here of the order of 1 MHz. A simple model is proposed to describe the impulsive noise... View full abstract»

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  • A Simulation Study of Some Dynamic Channel Assignment Algorithms in a High Capacity Mobile Telecommunications System

    Publication Year: 1973, Page(s):1294 - 1301
    Cited by:  Papers (52)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (568 KB)

    This paper reports the results of an investigation of the increase in traffic capacity in a cellular high capacity mobile telecommunications system attainable with dynamic instead of fixed channel assignment. Three dynamic channel assignment algorithms were studied by simulation using a 21-cell hexagonal array as a representative system layout. Detailed results for each algorithm are presented. Fo... View full abstract»

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  • New Concepts in Spectrum Usage

    Publication Year: 1973, Page(s):1172 - 1176
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (552 KB)

    The author alleges that there is no shortage of radio spectrum, but rather, a shortage of new concepts in spectrum usage. The recent reallocation of additional frequencies to land mobile radio uses (FCC Dockets 18 261 and 18 262) provides new opportunities for innovative approaches, approaches that are free of the constraints of existing rules and regulations, existing manufacturing and engineerin... View full abstract»

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  • A Mobile Radio Single-Frequency "Two-Way" Diversity System Using Adaptive Retransmission from the Base

    Publication Year: 1973, Page(s):1241 - 1247
    Cited by:  Papers (7)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (736 KB)

    This paper describes an adaptive retransmission system capable of providing a UHF (1 GHz) mobile radio channel with "twoway diversity." The system is unique in that all signal processing associated with the diversity combining is done at the base station. A two-branch prototype of the system, without modulation, was field tested to determine its adaptive retransmission performance. These tests ind... View full abstract»

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  • 900 MHz Land Mobile Radio Improved Using Circular Polarization

    Publication Year: 1973, Page(s):1321 - 1323
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB)

    Land mobile systems currently use vertically polarized antennas while trying to solve the problem of small sector signal variations, which are greater for vertical polarization than for either horizontal or circular polarization; This difference in small sector variations is shown from results of tests at 430 MHz. The variations at 900 MHz should be more rapid and have amplitudes at least as great... View full abstract»

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  • Analysis of Radio Paging Errors in Multitransmitter Mobile Systems

    Publication Year: 1973, Page(s):1310 - 1318
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (880 KB)

    Many mobile telephone and personal paging systems require signaling simultaneously from multiple transmitters. This paper analyzes the factors that cause paging errors due to interference when the signaling format consists of audio tones sent simultaneously from two FM transmitters. The factors considered are: drift in carrier and modulation frequencies, and misequalization of land-line amplitude ... View full abstract»

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  • Performance of Feedback and Switch Space Diversity 900 MHz FM Mobile Radio Systems with Rayleigh Fading

    Publication Year: 1973, Page(s):1257 - 1268
    Cited by:  Papers (33)  |  Patents (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (952 KB)

    A theoretical and experimental comparison of performance has been made between two types of predetection switching space diversity mobile radio systems. This comparison was made at a frequency of 840 MHz using simulated Rayleigh fading for a vehicle speed of about 80 mi/h. The switch diversity system was a conventional receiver antenna switching technique with two simulated physically separated re... View full abstract»

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  • The Statistics of the In-Phase Component of the Branch Signal in a Pilot-Derived Maximal Ratio Diversity Combiner

    Publication Year: 1973, Page(s):1319 - 1320
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (200 KB)

    An often-discussed scheme for providing maximal ratio combining in mobile radio is to set the complex branch gain according to the amplitude and phase of a pilot sent with the carrier. The in-phase component of the branch signal in such a system has a simple doubleexponential distribution. These and other relevant statistics are derived. View full abstract»

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  • Switching Plan for a Cellular Mobile Telephone System

    Publication Year: 1973, Page(s):1281 - 1286
    Cited by:  Papers (6)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (632 KB)

    Federal Communication Commission Docket 18 262 allocated a 75-MHz band to the common carriers to implement high capacity mobile telephone systems. The Bell System has proposed a cellular arrangement of low-power transmitters/receivers that permits frequency reuse in a coverage area. This method of achieving spectrum efficiency will require extensive centralized coordination and control to properly... View full abstract»

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  • Statistical Estimation of Mean Signal Strength in a Rayleigh-Fading Environment

    Publication Year: 1973, Page(s):1207 - 1213
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (520 KB)

    A commonly used model for signal fading in many types of communication channels is that the amplitude of the received signal at a given time is a Rayleigh-distributed random variable. In this paper we show how classical statistical techniques may be applied to the problem of estimating the Rayleigh distribution parameter (i.e., the mean), given samples from the distribution. In particular, we firs... View full abstract»

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Aims & Scope

IEEE Transactions on Communications focuses on all telecommunications including telephone, telegraphy, facsimile, and point-to-point television by electromagnetic propagation.

 

 

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Naofal Al-Dhahir
University of Texas at Dallas