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Communications, Radar and Signal Processing, IEE Proceedings F

Issue 5 • Date August 1987

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Displaying Results 1 - 14 of 14
  • Measurements for telecommunications transmission systems

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    Freely Available from IEEE
  • Circuit structures for high-digit-rate bit error ratio measurements

    Page(s): 434 - 438
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (596 KB)  

    Series-parallel signal generation and processing techniques are identified which may be used to circumvent the speed limitations of available logic devices in realising bit error ratio measurements for high-digit-rate transmission systems. New techniques are proposed which offer advantages in enabling devices to be used near their maximum operating rate while achieving, by virtue of the parallelism inherent in the structures proposed, yet higher data throughout rates. The specific application of these techniques to highspeed line-coded test signal generation and error detection is examined, and the series-parallel generators are shown to be particularly well suited to the economical realisation of mB(m+1)B block-coded test signals. View full abstract»

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  • Fast measurement of bit error rate in digital links

    Page(s): 439 - 447
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    A Gaussian regression algorithm is proposed for reducing bit error rate (BER) measurement time and facilitating, by extrapolation, a bit error probability estimation as a function of the signal/noise ratio. The application of this algorithm is illustrated in two BER measurement methods using noise injection or decision threshold level shifting. The overall performance assessment of a system (error probability as a function of the signal/noise ratio and noise standard deviation in the absence and in the presence of the signal) are thus obtained. View full abstract»

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  • Practical error probability estimation for digital radio systems in the presence of interference and noise of finite crest factor, and prediction of residual error rate

    Page(s): 448 - 453
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (627 KB)  

    The probability of incorrect reception of a transmitted bit under hostile propagation conditions is commonly estimated from bit error ratio measurements performed in the presence of additive white noise and interference. The paper stresses the effects of the finite crest factor of realisable noise sources on the theoretical error probability of digital radio systems. Formulas are presented for calculating this under given combinations of noise, interference and crest factor for common modulation schemes, and are suitable for simple numerical integration on desk-top calculators. Some implications for test equipment design are highlighted. The residual error rate of digital radio systems is so low that it is not practical to measure it directly. However, an estimate can be made by adding sinusoidal interference to produce the carrier/interference ratio (CIR) required to establish a specific error rate, dependent on the amount of residual noise present around the phase states in the constellation employed. View full abstract»

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  • Measurement method for eye opening estimation on digital signals

    Page(s): 454 - 458
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (632 KB)  

    For constructing reliable, high-grade digital transmission networks, exact failure or degradation detection in digital transmission equipment, such as regenerative repeaters, is important. A new measurement for eye opening estimation of equalised signals, called the transmission waveform deflection-type margin (TWDM) measuring method, is proposed. The principles of the method are described and the measurement accuracy in relation to measurement time required is analysed. Experimental results are presented and the measurement method shown to have a wide range of applications. View full abstract»

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  • Error detection in operating digital systems: influence of error distribution

    Page(s): 459 - 463
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    Different statistical distributions of errors (isolated and in bursts) were provoked on digital systems. Binary errors and errors estimated by `coding rule violations¿ were compared for the HDB3 and 4B3T codes. In the case of the HDB3 code, 85% of isolated binary errors are detected. However, only 15% of burst errors are detected. In the case of 4B3T with an asynchronous scrambler, it may be considered that one code error corresponds to 10 binary errors, on average. Results with burst errors are quite different from theoretical evaluation for isolated errors. These results must be considered when evaluating `degraded minutes¿ and `severely errored seconds¿ of CCITT Recommendation G.821 for operating digital systems. View full abstract»

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  • Assessment of timing jitter in digital telecommunications transmission systems

    Page(s): 464 - 473
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    The topics of jitter origin, accumulation and control are vitally important in digital systems and networks, and form an important part of the relevant performance specifications. The principal properties of jitter are summarised and the philosophy behind current international specifications explained. A review of measurement requirements and techniques for testing the jitter performance of digital transmission equipment is given, and the paper concludes with a brief consideration of jitter assessment in systems and networks of the future. View full abstract»

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  • Subscriber loop noise measurements and calibration

    Page(s): 474 - 480
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    An assessment of subscriber loop copper pairs for digitised data transmission includes capturing the effects of noise such as crosstalk, background noise and impulse noise on the quality of transmission. In the paper we present results of a subscriber loop noise measurement survey conducted within GTE. Calibration for impulse-noise field measurements, which estimate impulse arrival rate ¿¿ and the standard deviation of the impulse amplitude distribution, ¿¿v, are also described. The effect of noise on the performance of a digitised loop is discussed. View full abstract»

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  • Fast measurement of telephone channel phase characteristics. Part 1: Method description

    Page(s): 481 - 486
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (716 KB)  

    A procedure for measuring the frequency shift and phase jitter of telephone data channels in the voice frequency band (300-3400 Hz) is presented. Rather than processing a received signal to obtain the required measurements, the phase is extracted and processed by a `phase filter¿¿. An implementation of the phase filter is described which utilises power-2 coefficients to avoid the need for multiplication. This procedure is based on modern signal processing techniques which allow both simple and fast operation when implemented using a microprocessor. The technique can thus be easily incorporated into a telephone line measuring equipment or communication network monitoring system. Simulation results are given showing the effect of noise on the accuracy of the proposed algorithm, and some methods for the reduction of noise are also described. The trade-offs between the test signal duration and measurement accuracy are also considered. View full abstract»

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  • Fast measurement of telephone channel phase characteristics. Part 2: Method analysis

    Page(s): 487 - 491
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    A fast algorithm for measuring the frequency shift and phase jitter of telephone data channels which uses simple methods for extracting and processing the phase information of a received test signal was described in Part 1. A detailed analysis is now carried out for the Hilbert transformer and phase filter. The Hilbert transformer requires only one delay element, and two additions for each signal sample, and is thus attractive for general phase extraction applications with sinusoidal signals. View full abstract»

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  • Performance of a communications system monitor

    Page(s): 492 - 498
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (870 KB)  

    The paper gives details of the performance and accuracy of the communications system monitor (CSM) which is used in conjunction with the Australian National Satellite System (AUSSAT). The equivalent isotropic radiated power (EIRP), frequency and carrier/noise ratio of all carriers are routinely monitored by the CSM as well as a range of baseband parameters for FM/TV and FDM/FM signals. The CSM capability to measure a number of satellite parameters and obtain remote antenna patterns is described. Details are provided of the accuracy of the CSM as determined during extensive factory testing. The results show that the CSM is a very accurate system for the monitoring of both satellite traffic and satellite transponder parameters. Procedures used for setting up carriers for the testing of the CSM are also included. The results presented are those obtained during extensive factory testing of the system. Following installation of the CSM additional carrier types and measurements have been incorporated in the system. View full abstract»

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  • Integration and testing of an SS-TDMA 120 Mbit/s regenerative repeater for advanced communications satellites at K-band

    Page(s): 499 - 509
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    The paper deals with a test campaign performed on a regenerative repeater with an onboard baseband switching matrix (BBSM), able to set up a satellite-switched, time-division multiple-access (SS-TDMA) system. We first address the optimisation of the transmission channel (filters, TWTA back-off etc. ) on the basis of BER measurements, and then examine some functional tests including a TDMA terminal as a traffic terminal simulator. View full abstract»

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  • Automated microwave testing of spacecraft

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    Preflight evaluation of the performance of the communications subsystem of communications satellites is a rigorous and demanding task. It involves exposing the spacecraft to predicted environments while interspersing performance measurements that evaluate subsystem performance. The International Business Service (IBS) version of the Intelsat VA satellite has more than 1500 different pathways that can be utilised to relay a microwave signal through the satellite. The large number of pathways to be tested adds another degree of complexity to the test programme and creates a critical need for high-speed automated testing. These requirements affected the evolution of the latest generation of microwave automatic test equipment (MATE) in several areas: closed-loop path configuration, user-friendly operator interface, multitasking capability, equipment and peripheral selection, self-test capability, microprocessor-based custom peripherals, and development/reconfiguration cost. The test measurement requirements and the techniques used to implement them are discussed. The requirements have been cost-effectively satisfied in a system that has the flexibility to handle spacecraft requirements. In addition to providing highspeed automated testing, data analysis and display, the system allows for quick reconfiguration and test method restructuring when required for investigation of anomalous performance or introduction of special tests. View full abstract»

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  • IEE Conference Publication 278

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    Freely Available from IEEE

Aims & Scope

The latest version of this title is Radar, Sonar & Navigation, IET.

Full Aims & Scope