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Communications, Radar and Signal Processing, IEE Proceedings F

Issue 6 • Date October 1985

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Displaying Results 1 - 16 of 16
  • Line code design for digital pulse-position modulation

    Page(s): 441 - 446
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1066 KB)  

    A class of finite-state alternate alphabetic line codes, designated mBL-K, is identified and studied in the context of digital pulse-position modulation (PPM). The influence on code properties of the number of time slots per PPM frame and the number of frames per code word is considered, and a specific 9B2-33 code is identified which is particularly well suited to digital optical-fibre PPM transmission. View full abstract»

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  • An alternative formulation for an optimum beamformer with robustness capability

    Page(s): 447 - 460
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1063 KB)  

    In the paper, an alternative formulation for an optimum beamformer with a robustness capability against directional errors is presented. With this approach, the width of the main beam can be specified and a compromise can be reached between a reasonable signal acceptance angle and the ability of the beamformer to reject directional interferences. Furthermore, based on a partitioned processor interpretation, the new beam-former gives a clue to a way of reducing the complexity of a full processor. View full abstract»

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  • New method for computation of error probability in PSK systems with interference

    Page(s): 461 - 465
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (409 KB)  

    A very efficient technique for the computation of error probability in ASK systems with M = 2 m (m an integer) symbols or QASK systems with M2 symblos in the presence of intersymbols interference was presented by Jenq, Liu and Thomas, and this technique was extended by Jenq to coherent PSK (no phase jitter) with M = 2, 4 and 8 symbols. In the present paper we extend this technique to PSK (phase jitter or misalingnment is possible) with 8 and 16 symbols by deriving lower and upper bounds which are close to each other. View full abstract»

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  • Systolic implementations for deconvolution, DFT and FFT

    Page(s): 466 - 472
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (875 KB)  

    The paper presents a number of systolic configurations for computing deconvolutions and discrete Fourier transformations. Two approaches to deconvolution are considered: a time-domain approach, which is based on a systolic inversion of an associated Toeplitz matrix, generated by a wavefront propagation of the known system response, while the other approach, which is in the frequency domain, utilises systolic discrete Fourier transform (DFT) and fast Fourier transform (FFT) processors. The latter employs a systolic elevator concept, which circumvents the traditional need for global communications in the FFT. Aspects of hardware implementation and speed trade-offs are also discussed. View full abstract»

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  • Bit-level systolic array implementation of the winograd fourier transform algorithm

    Page(s): 473 - 479
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (877 KB)  

    A bit level systolic array system is proposed for the Winograd Fourier transform algorithm. The design uses bit-serial arithmetic and, in common with other systolic arrays, features nearest-neighbour interconnections, regularity and high throughput. The short interconnections in this method contrast favourably with the long interconnections between butterflies required in the FFT. The structure is well suited to VLSI implementations. It is demonstrated how long transforms can be implemented with components designed to perform a short length transform. These components build into longer transforms preserving the regularity and structure of the short length transform design. View full abstract»

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  • Code-division multiplex technique using bridge functions

    Page(s): 480 - 484
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (442 KB)  

    A code-division multiplexing technique using a set of orthogonal functions known as bridge functions as carrier codes has been investigated. These functions are three-valued functions which take the values +1, 0 and ¿¿1. The results of a computer simulation on the performance of the system in additive white Gausian noise are presented, and the system is compared with conventional time-division multiplexing. View full abstract»

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  • Conference report: 6th Symposium on Information Theory in the Benelux (Mierlo, The Netherlands, 23rd¿24th May 1985)

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    Freely Available from IEEE
  • Near-maximum-likelihood detectors for binary signals

    Page(s): 485 - 490
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (777 KB)  

    The paper studies three developments of a class of near-maximum-likelihood detection processes derived from a conventional nonlinear (decision feedback) equaliser. The new detectors are suitable for binary signals transmitted over a linear baseband channel introducing severe amplitude distortion. The complexity of the processes is not excessive, and increases approximately linearly with the delay in detection. Thus, a sufficiently large delay in detection can be employed to achieve a near-optimum tolerance to noise when the received signal has been very severely distorted. The paper describes three novel detection processes, and presents the results of computer simulation tests, comparing the tolerances to additive white Gaussian noise of various arrangements of each detector with that of the optimum detector of the given class and that of a conventional nonlinear equaliser. Three different channels are used in the tests and binary signals are transmitted in every case. View full abstract»

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  • Maximum entropy processing of band-limited spectra. Part 1: Noise-free case

    Page(s): 491 - 497
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (657 KB)  

    The maximum entropy method assumes that the spectrum exists up to the Nyquist frequency. For array processing of low-frequency signals, the spectrum often only exists over part of the wavenumber interval. This paper generalises the maximum entropy methods to correctly model this situation. Simulations are included which show the performance of the technique. View full abstract»

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  • Maximum entropy processing of band-limited spectra. Part 2: Recovering a spectrum from noisy measurements

    Page(s): 498 - 504
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (764 KB)  

    The paper presents a maximum entropy technique for recovering a band-limited spectrum from noisy measurements. It is demonstrated that the new technique is capable of forming a good reconstruction of a band-limited spectrum. Simulations are included for both the deterministic case and for sampled covariance matrices. View full abstract»

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  • Book review: Microcomputer Tools for Communications Engineering

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    Freely Available from IEEE
  • Dimensioning technique for meteor-burst communication systems

    Page(s): 505 - 510
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (841 KB)  

    A convenient technique for the analysis of meteor-burst communication systems is presented, and it is shown how the probability densities of burst duration and burst interval can be predicted from the system parameters. The technique is based on an extension of generally accepted theory combined with experimental results, and a set of simple equations is obtained. The theoretical derivations are closely related to the physical phenomena involved. An experimental verification programme was undertaken in September 1982. The measurements made showed good agreement with the predicated values. View full abstract»

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  • Analysis of a multilink system in the presence of noise, cochannel interference and some hardware imperfections

    Page(s): 511 - 516
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (642 KB)  

    The paper presents a further development of the theoretical analysis that has been devoted to the terrestrial or satellite system with Gaussian noise and one cochannel intereference per link. The specific aims of the paper are to simplify the performance analysis of the multilink system by introducing an estimate on the upper and lower bound of the symbol error rate, and to present in analytical form the impact of some imperfections (noise of preamplifier, internal interference of cochannel type, internal noise, jitter produced by the first and second local oscaillators) that exist in each repeater as well as in the receiver of an m -ary CPSK or DCPSK system. It is assumed that the repeater output amplifier is a bandpass hard-limiter type (the BPHL type), and that noise and interference act independently on each link of the system. View full abstract»

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  • Cellular mobile packet radio using multiple-channel CSMA

    Page(s): 517 - 526
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1427 KB)  

    One way to increase frequency spectrum utilisation in a mobile communication system is to divide the geographical region spatially into a number of cells, each of which contains a base station. Each base station is assigned a set of channels, and the users in the neighbourhood of a base station can transmit their messages to the base station. Several protocols governing the access to the base station channels are available. The paper considers multichannel CSMA schemes embedded in a spatially celluar communication environment. Several alternative ways of organising the system resources, layout and protocol are considered. The complexity of the system is progressively increased, culminating in the general case: each base station is assigned a set of Cachannels and users access any one of the k nearest base stations with multichannel CSMA protocol. The performance characteristics of the system¿¿normalised delay against system bandwidth utilisation¿¿are given in terms of the system parameters. The several configurations considered are compared based on the delay, band-width utilisation and interference rejection characteristics. View full abstract»

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  • IEE Colloqium report: IEE Colloquium on Digital Audio Signals in Studio Centres

    Page(s): 526 - 527
    Save to Project icon | PDF file iconPDF (293 KB)  
    Freely Available from IEEE

Aims & Scope

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

Full Aims & Scope