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Communications, Radar and Signal Processing, IEE Proceedings F

Issue 1 • Date February 1987

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Displaying Results 1 - 21 of 21
  • Telephoning on the move¿Dick Tracy to Captain Kirk

    Page(s): 1 - 8
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1684 KB)  

    For Dick Tracy of comic-strip fame and Captain Kirk of `Star Trek¿, voice communication from tiny equipment over vast distances posed no problem, but in the real world of 1986 the situation is much more difficult. Historically, mobile telephone systems using HF, VHF and UHF radio have been developed since the Second World War with military and commercial systems evolving in parallel. Although often the military needs have led the technological developments, more recently civil systems have been taking the lead in many areas. Initially voice communication by mobile radio operated in closed groups of users on an `all-informed¿ basis, but, more recently, connection to the world's telephone network has been possible and incoming calls are automatically routed to mobile subscribers wherever they may be in the system¿a real breakthrough in the concept of personal communication. But can this be extended ultimately to a worldwide system? And can the hardware really approach the convenience available to Dick Tracy and Captain Kirk? The paper considers some of the technical problems to be overcome in terrestial radio systems and touches on the prospects for satellites to play a role in this, but concludes that it will be some time before we can match the facilities available to our fictional heroes. View full abstract»

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  • Effect of sampling offset on Pe performance of partial response systems

    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (381 KB)  

    The paper applies the Gram-Charlier series method to the calculation of the probability of error Pe of partial response (PR) systems. This method allows the exact calculation of error probability including the effects of sampling off-set and additive Gaussian noise. Five classes of precoded PR systems are considered. The results obtained in the method are compared with those obtained with Chernoff bounds. View full abstract»

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  • Pseudoternary partial response FSK

    Page(s): 13 - 19
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (615 KB)  

    We show how to compute the error probability of frequency-shift keying with limiter-discriminator-integrator detection in the presence of narrowband filters in the transmitter and receiver when the symbols are pseudoternary, i.e. they are generated from binary symbols using duobinary, modified duobinary and dicode rules. We show numerical results assuming a Butterworth filter in the receiver with 2, 3 and 4 poles. We optimise the sampling time, frequency deviation, filter bandwidth and threshold setting, and the conclusion is that the duobinary is the best partial response system. However, when compared with an uncoded, binary system the duobinary system is better only when the bandwidth is very small. View full abstract»

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  • Book review: Fast Algorithms for Digital Signal Processing

    Page(s): 19 - 20
    Save to Project icon | PDF file iconPDF (294 KB)  
    Freely Available from IEEE
  • Error rate prediction for NCFSK digital mobile radio systems

    Page(s): 21 - 26
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (702 KB)  

    Error performance analysis for the VHF digital mobile radio system is presented. The binary frequency-shift keying (FSK) system using noncoherent (NC) demodulation, with a limiter/discriminator receiver, is considered. All major error-causing factors, such as signal fading, Gaussian and impulsive noise, are taken into account and the corresponding general expression for the error probability is derived. This expression is then applied to the bit error rate (BER) evaluations for the three adequate receivers, described by the different mathematical models of their impulse responses. The calculated BER values are compared to the results obtained by measurements on the real laboratory models simulating the mobile radio systems considered. In conclusion, the mathematical model for the receiver impulse response yielding the best prediction results, when using the derived expression for the BER calculation, is proposed. View full abstract»

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  • Postdetection diversity using a modified phase-correction loop for digital land mobile radio

    Page(s): 27 - 34
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (800 KB)  

    A postdetection diversity system using a phase-correction loop modified by the inclusion of a differential demodulator (DD) or a frequency demodulator (FD) is described. Binary and quaternary digital modulation for DPSK and digital FM are considered. An analysis considering additive Gaussian noise shows that, although the diversity combiner proposed is inherently the postdetection type, the well known predetection equal-gain combining (EGC) or maximal-ratio combining (MRC) action can be approximately achieved. A unified analysis of bit error rate (BER) is presented for a Rayleigh fading environment, and fairly simple results are obtained. It is shown that the diversity gain of postdetection EGC is about 0.62 dB inferior to that of postdetection MRC when two-branch diversity is employed. View full abstract»

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  • Log-normal clutter cancellation

    Page(s): 35 - 42
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (712 KB)  

    The problem of clutter cancellation in a non-Gaussian environment is becoming more and more important in modern high-resolution radars, owing to uncertain clutter statistics. To evaluate the MTI canceller performances, in the paper we examine an intermediate frequency model which gives, in the video frequency, a signal with log-normal (LN) probability density function (PDF). The improvement factor needed to obtain optimum detection performances in a multiclutter environment will be evaluated. View full abstract»

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  • IEE Conference Publication 271

    Save to Project icon | PDF file iconPDF (129 KB)  
    Freely Available from IEEE
  • Rotationally invariant coded PSK signals

    Page(s): 43 - 52
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1320 KB)  

    The paper describes the design of eight new rotationally invariant rate-2/3 and rate-3/4 convolutional codes. The rate-2/3 codes are suitable for 8PSK (8-level PSK) coded signals and are transparent to phase rotations in the received signal carrier phase, that are multiples of ¿¿/2 radians, whereas the rate-3/4 codes are suitable for 16PSK (16-level PSK) coded signals and are transparent to phase rotations that are multiples of ¿¿/4 radians. The new codes are bandwidth-efficient and, when combined with a simple carrier-phase correction system described in the paper, they are able to tolerate the likely carrier-phase changes in the reference carrier of the coherent demodulation process. Thus they avoid the prolonged error bursts that are otherwise caused in the detected data symbols by such phase shifts. Among these codes, two rotationally invariant rate-3/4 codes have been found with minimum free distances equal to those of the optimum but not rotationally invariant codes, having the same rates and constraint lengths. The majority of the codes designed here have asymptotic coding gains which are only up to about 0.5 dB inferior to those of the corresponding optimum but not rotationally invariant codes. Extensive computer simulation tests have been carried out on the various codes studied, and these have confirmed the optimum or near-optimum performances that have been theoretically predicted for these codes. View full abstract»

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  • Angular superresolution with phased array radar: a review of algorithms and operational constraints

    Page(s): 53 - 59
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1161 KB)  

    A number of methods have been suggested to improve spectral or angular resolution. These methods have arisen from quite different fields of application, and are difficult to compare. The paper collects aspects for the application of such methods to the case of angular resolution with a phased array radar. We list the main methods and their properties, and point out constraints for a real radar application. View full abstract»

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  • IEE Conference Publication 268

    Page(s): 59 - 60
    Save to Project icon | PDF file iconPDF (289 KB)  
    Freely Available from IEEE
  • Power spectra of CPFSK waveforms, having nonuniform input PDFs

    Page(s): 61 - 68
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (622 KB)  

    Power spectral density (PSD) analysis is often undertaken assuming equally likely signalling input levels, and hence the different criteria of performance are evaluated with this condition in mind. In practice, however, cases of unequal probabilities of signalling input do arise due to choice of coder, and the study of these conditions is important. Power spectral densities are sensitive to variations in the probability density functions (PDFs), and both these curves and the fractional out-of-band spectra for multilevel FSK are treated in the paper. Different signalling inputs are used for M-ary CPFSK and the newly defined multi-h partial response (MHPR) scheme. The influence of PDFs on creating spectral lines (for timing extraction) is also discussed. View full abstract»

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  • Analysis of transient data in noise

    Page(s): 69 - 78
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1013 KB)  

    A linear prediction method for accurately estimating the parameters of a rational model of transient-type data is presented. This method makes use of the singular value decomposition of an extended-order autocorrelation-like matrix estimate associated with the time series being analysed. The method is first tested on simulated data consisting of three exponentially damped sinusoids of closely spaced frequencies in additive white Gaussian noise. Next, the method is used to analyse nuclear magnetic resonance (NMR) data. View full abstract»

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  • Performance evaluation of packet-switched networks with retransmission due to finite buffers and channel errors

    Page(s): 79 - 84
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (759 KB)  

    The equilibrium behaviour of store-and-forward packet-switched networks is studied under realistic conditions via a network of queues. A network with a general mesh topology is considered. Switching nodes have a finite number of store-and-forward buffers, and communication channels are not perfect. A node-node protocol with positive acknowledgment and retransmission is modelled, and consumes part of the channel buffers. A new approach is employed to obtain buffer overflow probabilities using a truncated multiserver queue with channel buffers being both the servers and the storage places. The developed model accounts explicitly for the acknowledgment delays and interactions among adjacent queues. The principal results are mean buffer size and overflow probability, retransmission probability and the mean delays as functions of the number of buffers, traffic levels and the error rate of data transfer. The developed model is validated by comparison with simulation results. View full abstract»

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  • Multiple criteria for hand-off in cellular mobile radio

    Page(s): 85 - 88
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (542 KB)  

    A cellular hand-off treatment based on cell membership degrees is presented. The proposed method permits the systematic incorporation of a variety of different weight criteria. An example of application is given, and it is shown that the procedure leads to a low number of handoffs without excessive cell coverage overlapping. If one of the criteria is derived from traffic levels, then traffic imbalance may be reduced without recourse to channel borrowing. View full abstract»

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  • New approach to improved detection and tracking performance in track-while-scan radars. Part 1: Introduction and review

    Page(s): 89 - 92
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (591 KB)  

    The paper presents a new approach to improve the detection and tracking performance of a track-while-scan (TWS) radar. The contribution consists of three parts. In Part 1 the scope of various papers in this field is reviewed. In Part 2, a new approach for integrating the detection and tracking functions is presented. It shows how a priori information from the TWS computer can be used to improve detection. A new multitarget tracking algorithm has also been developed. It is specifically oriented towards solving the combinatorial problems in multitarget tracking. In Part 3, analytical derivations are presented for quantitatively assessing, a priori, the performance of a track-while-scan radar system (true track initiation, false track initiation, true track continuation and false track deletion characteristics). Simulation results are also shown. View full abstract»

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  • New approach to improved detection and tracking performance in track-while-scan radars. Part 2: Detection, track initiation and association

    Page(s): 93 - 98
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (909 KB)  

    The paper presents, in three parts, a new approach to improve the detection and tracking performance of a track-while-scan (TWS) radar. Part 1 presents a review of current status. In this part, Part 2, it is shown how the detection can be improved by utilising information from tracker. A new multitarget tracking algorithm, capable of tracking manoeuvring targets in clutter, is then presented. The algorithm is specifically tailored so that the solution to the combinatorial problem presented in a companion paper can be applied. The implementation aspects are discussed and a multiprocessor architecture identified to realise the full potential of the algorithm. Part 3 presents analytical derivations for quantitative assessment of the performance of the TWS radar system. It also shows how the performance can be optimised. View full abstract»

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  • New approach to improved detection and tracking performance in track-while-scan radars. Part 3: Performance prediction, optimisation and testing

    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1704 KB)  

    The paper presents, in three parts, a new approach to improve the detection and tracking performance of a track-while-scan radar. Part 1 presents a review of the current status of the subject. Part 2 details the new approach. It shows how a priori information provided by the tracker can be used to improve detection. It also presents a new multitarget tracking algorithm. In the present Part, analytical derivations are presented for assessing, a priori, the performance of the TWS radar system. True track initiation, false track initiation, true track continuation and false track deletion characteristics have been studied. It indicates how the various thresholds can be chosen by the designer to optimise performance. Simulation results are also presented. View full abstract»

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  • Combinatorial problems in multitarget tracking¿a comprehensive solution

    Page(s): 113 - 118
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (826 KB)  

    The paper presents a new solution to the combinatorial problems that arise when multiple targets are to be tracked simultaneously. In multitarget situations, the correspondence between targets and observations may be lost because of crossing trajectories, close-by targets, false alarms, missed detections etc. The number of data association hypotheses that are feasible and for which probabilities have to be calculated is extremely large in any but the smallest of such problems. We present a new algorithm for locating the N globally best hypotheses using a simple search method instead of extensive enumeration or integer programming methods. View full abstract»

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  • Data Compression and Error Control Techniques and Applications

    Page(s): 118 - 119
    Save to Project icon | PDF file iconPDF (347 KB)  
    Freely Available from IEEE
  • Radar Data Processing, vols. 1 and 2

    Page(s): 119 - 120
    Save to Project icon | PDF file iconPDF (248 KB)  
    Freely Available from IEEE

Aims & Scope

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

Full Aims & Scope