By Topic

Communications, IEEE Transactions on

Issue 7  Part 2 • Date July 1982

Filter Results

Displaying Results 1 - 25 of 50
  • [Front cover and table of contents]

    Publication Year: 1982 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (299 KB)  
    Freely Available from IEEE
  • Guest Editors' Prologue - Special Issue on Transmultiplexers

    Publication Year: 1982 , Page(s): 1457 - 1460
    Save to Project icon | Request Permissions | PDF file iconPDF (486 KB)  
    Freely Available from IEEE
  • On Computational Complexity in Digital Transmultiplexer Filters

    Publication Year: 1982 , Page(s): 1461 - 1465
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (497 KB)  

    The quality standards recommended by the CCITT are the reference for the design of digital transmultiplexer filters. Their impact on filter specifications is analyzed, and expressions are given for the filter order, coefficient, and data word lengths in FIR and IIR approaches. Improvements on the polyphase filter bank design are pointed out, and the method is presented as a hybrid FIR-IIR techniqu... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Digital Two-Rate IIR and Hybrid IIR/FIR Filters for Sampling Rate Conversion

    Publication Year: 1982 , Page(s): 1466 - 1476
    Cited by:  Papers (4)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (982 KB)  

    The paper discusses structures, design methods, and efficiency of digital two-rate filters for sampling rate alteration by integer or rational ratios. Four canoic filter structures are demonstrated: the direct form, the parallel form, the ladder/lattice forms, and a structure based on canonic all-pass sections. In addition, a structure exploiting numerator coefficient symmetry is presented. An ext... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Computationally Efficient Determination of D/A and A/D Noise in Digital Transmultiplexers

    Publication Year: 1982 , Page(s): 1477 - 1482
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (464 KB)  

    Component inaccuracies in the D/A and A/D converters found in digital transmultiplexers introduce noise to the signals being converted. When the imperfections considered include finite impedances of current sources in switched current source R/2R ladders (equivalent to nonzero impedances in switched voltage source converters), the number of computations needed to find the error at ev... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Impact of Some CCITT Recommendations on Transmultiplexer Design

    Publication Year: 1982 , Page(s): 1483 - 1492
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (843 KB)  

    A short description of the transmultiplexer structure is given, and a brief review of some significant CCITT recommendations is presented. The paper briefly explains the influence of these recommendations on the design of the main subblocks of a back-to-back configurated transmultiplexer, the main subblocks being the two baseband filters, the two o2DFT processors and the two chan... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Exploitation of Transmultiplexers in Telecommunication Networks

    Publication Year: 1982 , Page(s): 1493 - 1497
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (581 KB)  

    The functions and exploitation options which make possible and facilitate the introduction of transmultiplexers in existing telecommunication networks are presented and discussed. A few selected cases of interconnection between analog and digital links illustrate the need for convenient alarm processing and adequate operation options. The definition of alarms is detailed and indications are given ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design of a Digital Transmultiplexer Using Standard Low-Power Schottky TTL Logic

    Publication Year: 1982 , Page(s): 1498 - 1505
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (675 KB)  

    The introduction of digital transmission systems and switches in the present analog network necessitates an optimized economical and technical interface solution. To meet these objectives a transmultiplexer, based on digital signal processing, was built. The transmultiplexer converts between two 30-channel primary PCM systems and one 60-channel FDM supergroup, the R2 signaling included. The purpos... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design of FIR Filter Banks for a 24-Channel Transmultiplexer

    Publication Year: 1982 , Page(s): 1506 - 1510
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (578 KB)  

    The design of a bank of FIR bandpass filters for channel filtering and sample rate alteration in a 24-channel transmultiplexer is considered. It is shown that such a filter bank can be realized by the combination of a weighting network and a discrete cosine transform. A minimum phase design is suggested for the low-pass prototype filter in order to solve the long absolute delay problem inherent in... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Digital 60 Channel Transmultiplexer: Algorithm Minimizing Multiplication Rate and Hardware Implementation

    Publication Year: 1982 , Page(s): 1511 - 1519
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (769 KB)  

    A TDM/FDM conversion algorithm for realizing transmultiplexers with an FFT processor and a set of digital subfilters is proposed which provides a significant saving in multiplication rate. In the proposed algorithm in which an FDM signal is directly sampled, the dimension of the FFT processor is reduced by provision of pre- and postprocessing and the multiplication rate in radix-3 is reduced by re... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Per-Channel, Memory-Oriented Transmultiplexer with Logarithmic Processing

    Publication Year: 1982 , Page(s): 1520 - 1527
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (883 KB)  

    This paper describes a memory-oriented design for a digital transmultiplexer which performs conversion between TDM and FDM on a per-channel basis. The processor uses FIR bandpass filters which also perform interpolation (TDM-to-FDM) and decimation (FDM-to-TDM). Hardware efficiency is obtained by implementing the FIR filters in a logarithmic mode, wherein multiplication becomes addition. Conversion... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 24- and 120-Channel Transmultiplexers Built with New Digital Signal Processing LSI's

    Publication Year: 1982 , Page(s): 1528 - 1539
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1265 KB)  

    Two new digital transmultiplexers intended for commercial use have been developed. One transmultiplexer performs a bilateral conversion between two 12-channel FDM group signals and a 24-channel PCM carrier signal. The other mutually connects two 60-channel FDM supergroup signals and five 24-channel or four 30-channel PCM signals. Both exploit a block processing digital SSB-FDM multiplex/demultiple... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Modular Transmultiplexer System Using Custom LSI Devices

    Publication Year: 1982 , Page(s): 1540 - 1551
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1289 KB)  

    The design and operation of a 24- or 60-channel transmultiplexer based on a 12-channel signal processing module (or kernel) is described. The signal processing algorithm employs complex signal processing, and allows very low crosstalk and noise figures to be achieved without excessive group delay. The processing algorithm and the custom LSI devices used in its implementation were developed togethe... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • TDM-FDM Transmultiplexer Using a Digital Signal Processor

    Publication Year: 1982 , Page(s): 1552 - 1559
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (834 KB)  

    This paper describes a complete hardware implementation of a 24 channel transmultiplexer employing a digital signal processor. The algorithm for the TDM-FDM translation adopted here is a modification of the FFT and digital polyphase method. The modification is mainly directed towards the reduction of roundoff noise, so that the wordlength of the processor can be minimized. In this case, 16 bits fo... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Multiple VLSI Signal Processor Realization of a Transmultiplexer

    Publication Year: 1982 , Page(s): 1560 - 1568
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (783 KB)  

    A 12-channel TDM/FDM translator consisting of six VLSI digital signal processors is described. A filter bank which consists of a discrete cosine transform and a polyphase network of 14 filters is realized by three processors and effects the translation each way. One processor provides synchronization between the 96 kHz TDM and 112 kHz FDM signals and performs the cosine transform, and the remainin... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transmultiplexer Design Using All-Pass Filters

    Publication Year: 1982 , Page(s): 1569 - 1574
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (570 KB)  

    A new scheme for a transmultiplexer is described. Using the polyphase network approach a filter bank composed of only all-pass digital filter sections was designed. The use of all-pass filters as basic building blocks is shown to provide a transmultiplexer structure that has low computational requirements, low quantization noise, and high modularity. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transmultiplexers with Either Analog Conversion Circuits, Wave Digital Filters, or SC Filters--A Review

    Publication Year: 1982 , Page(s): 1575 - 1586
    Cited by:  Papers (19)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1264 KB)  

    Since more advanced transmultiplexer concepts have to compete with elementary alternative solutions derived from simple back-to-back connections, they have to aim at high efficiency and robust performance, the latter meaning that they should be quite insensitive against disturbances inherent to the type of technology adopted. Three solutions satisfying these requirements are reviewed, one for a mo... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • DSP-Based Implementation of a Transmultiplexer Using Wave Digital Filters

    Publication Year: 1982 , Page(s): 1587 - 1597
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (957 KB)  

    The multistep single-path multiplier-free conversion scheme proposed by Fettweis satisfies the requirement of robustness and seems to be attractive for transmultiplexers. This paper describes the implementation of a transmultiplexer based on this method using digital signal processors (DSP's). Since most of the currently available or proposed DSP's have sum-of -products type arithmetic units with ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Modular Approach to a Digital 60-Channel Transmultiplexer Using Directional Filters

    Publication Year: 1982 , Page(s): 1598 - 1613
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1288 KB)  

    A multistep transmultiplexer approach with a single-way modulation scheme applying minimum phase wave digital directional or transversal filter is proposed. Furthermore, the impact of signaling, pilots, and spectral shaping at the PCM end is investigated. The main merits of this approach are, at a moderate level of computational complexity, its absolute stability, the low basic group delay, and it... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transmultiplexer Realization with Multistage Filtering

    Publication Year: 1982 , Page(s): 1614 - 1622
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (733 KB)  

    Starting from the general principle of frequency shifting a 4 kHz bandwidth digital filter to perform the TDM-FDM conversion, a new decomposition of the filter is introduced. This decomposition allows for the use of a DFT of much lower dimension than the number of channels to be multiplexed, together with a few modulators (multipliers) working at the highest bit rate, and a tree configuration of f... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Analytic Signal Approach for Transmultiplexers: Theory and Design

    Publication Year: 1982 , Page(s): 1623 - 1628
    Cited by:  Papers (9)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (661 KB)  

    A new non-FFT approach to transmultiplexer implementation is presented, based on the theory of the baseband analytic signal and on its successive allocation in the FDM format by appropriate digital interpolation and filtering. The method allows wide transition bandwidths to the filters, avoids the use of any product modulator, and leads to a channel-by-channel structure. As a design example, the a... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Efficient and Modular Transmultiplexer Design

    Publication Year: 1982 , Page(s): 1629 - 1641
    Cited by:  Papers (9)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1042 KB)  

    A new transmultiplexer design is presented in which reliability is achieved by adopting a tree structure. A working principle based upon analytic signals results in a modular structure. The usage of FIR filters designed to have coefficients which are sums of a limited and prescribed number of powers of two together with an efficient, low-sensitivity interpolating structure results in a very effici... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transmultiplexer Via Spread-Spectrum Modulation

    Publication Year: 1982 , Page(s): 1642 - 1655
    Cited by:  Papers (2)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (897 KB)  

    A new scheme is derived for the digital TDM-FDM conversion (transmultiplexer) of N voice channels. In the complex version it simply consists of 1) a polyphase filter and 2) a modulator with carrier W2Nt2=exp(jt2/2N) where t is the normalized discrete time, both working at the rate of the TDM (or FDM) flux. T... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Study of Acknowledgment Schemes in a Star Multiaccess Network

    Publication Year: 1982 , Page(s): 1657 - 1667
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (905 KB)  

    In distributed random access communication, collision occurs when two or more transmissions overlap in time. After a transmission a user should know whether his attempt was successful so that he can decide his next action. Acknowledgments are commonly used to indicate whether a transmission is successful. The authors study the effect of acknowledgments on the performance of a star broadcast networ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Line Code Design for High-Capacity Baseband Digital Transmission Systems

    Publication Year: 1982 , Page(s): 1668 - 1678
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1122 KB)  

    A simple model for the intersymbol interference due to a low-frequency cutoff channel is presented. The model is used to develop a computationally efficient and accurate method for computing symbol error probability for alphabetically line-encoded sequences transmitted over this channel. The model is also used to design alphabetic line codes that minimize the symbol error probability. A method is ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

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
Robert Schober
University of British Columbia