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Communications, IEEE Transactions on

Issue 3 • Date Mar 1996

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Displaying Results 1 - 17 of 17
  • The Viterbi algorithm for sparse channels

    Publication Year: 1996 , Page(s): 287 - 289
    Cited by:  Papers (32)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (320 KB)  

    This paper presents a reduced complexity Viterbi algorithm for use as sequence estimator for linear intersymbol interference channels with coarsely located coefficients. In particular, the complexity does not depend on the channel impulse response length but only on the number of nonzero coefficients. No approximations are used in the algorithm. We consider a multipath environment producing time s... View full abstract»

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  • Blind equalization and estimation of FIR communications channels using fractional sampling

    Publication Year: 1996 , Page(s): 324 - 336
    Cited by:  Papers (20)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1092 KB)  

    We consider the problem of blind estimation and equalization of digital communication finite impulse response (FIR) channels using fractionally spaced samples. Fractionally sampled data are cyclostationary rather than stationary. The problem is cast into a mathematical framework of parameter estimation for a vector stationary process with single input (information sequence) and multiple outputs, b... View full abstract»

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  • Commonalities of several modulation techniques

    Publication Year: 1996 , Page(s): 298 - 300
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (256 KB)  

    We study commonalities of new bandwidth efficient and power efficient quadrature-quadrature phase shift keying (Q2PSK), constant envelope Q2PSK (CEQ2PSK), rotative QPSK (RQPSK), frequency and phase shift keying (FPSK), expurgated FPSK (E-FPSK), and the well-known orthogonal frequency division multiplexing (OFDM) (or multicarrier modulation) and L-orthogonal (LO) si... View full abstract»

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  • Pilot symbol-assisted detection of CPM schemes operating in fast fading channels

    Publication Year: 1996 , Page(s): 337 - 347
    Cited by:  Papers (29)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1048 KB)  

    We present a coherent detection technique for continuous phase modulation (CPM) operating in the Rayleigh flat fading channel. The technique is based on the idea of inserting periodically data dependent pilot symbols that force the CPM signal to pass through known phase states. This transmission format enables the receiver to extract from the received signal the channel fading gains at regularly s... View full abstract»

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  • Extended hyperbolic congruential frequency hop code: generation and bounds for cross- and auto-ambiguity function

    Publication Year: 1996 , Page(s): 301 - 305
    Cited by:  Papers (19)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (460 KB)  

    We propose a new frequency hop code, called the extended hyperbolic congruential (EHC) code. The properties of the code, determined via hit array analysis, indicate almost ideal cross- and auto-ambiguity characteristics. Furthermore, the code can be defined recursively, enabling a simple hardware implementation. This makes the code attractive for code division multiple access (CDMA) communication ... View full abstract»

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  • Practical constraints in growth of lightwave networks

    Publication Year: 1996 , Page(s): 348 - 355
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (816 KB)  

    The amount of fiber required, propagation delay, and length of the longest link are significant design constraints in spatially large networks. This paper examines these characteristics from the viewpoint of growth and compares basic networks with hierarchical ones in terms of these characteristics. Results show that, when considering growth from three nodes, a star network randomly placed with a ... View full abstract»

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  • Concatenated coding for frequency-hop spread-spectrum with partial-band interference

    Publication Year: 1996 , Page(s): 377 - 387
    Cited by:  Papers (15)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1048 KB)  

    Concatenated coding techniques are applied to slow frequency-hop packet radio communications for channels with partial-band interference. Binary orthogonal signaling (e.g., binary FSK) is employed with noncoherent demodulation, Reed-Solomon codes are employed for the outer code while both block and convolutional codes are considered for the inner code. Hard-decision and soft decision decoding meth... View full abstract»

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  • Optimization of symbol timing recovery for QAM data demodulators

    Publication Year: 1996 , Page(s): 399 - 406
    Cited by:  Papers (30)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (648 KB)  

    This paper describes an effective technique for the optimization of the clock recovery circuit in an all-digital modem for linearly modulated signals. Starting from the concept of prefiltering of the data signal (already pursued by these authors in the context of analog data receivers), it is shown how to design an optimum digital prefilter for the minimization of jitter due to both Gaussian and p... View full abstract»

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  • Decoding algorithms for noncoherent trellis coded modulation

    Publication Year: 1996 , Page(s): 312 - 323
    Cited by:  Papers (25)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1072 KB)  

    Noncoherent decoding of trellis codes using multiple-symbol overlapped observations was shown previously to achieve close to the coherent performance. Optimal decoding by the Viterbi algorithm for L-symbol observations requires a number of states which grows exponentially with L. Two novel suboptimal algorithms are presented, for which the number of states is the same as the original code, yieldin... View full abstract»

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  • Near-optimum quantization for signal detection

    Publication Year: 1996 , Page(s): 294 - 297
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (296 KB)  

    A heuristic approach to design quantizers for signal detection is presented. Quantizer parameters are obtained that minimize a tight upper bound on the probability of error. This approach is applied to the design of distributed detection systems. Numerical examples are presented to illustrate its near-optimum performance View full abstract»

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  • Cyclostationarity-based signal detection and source location in non-Gaussian noise

    Publication Year: 1996 , Page(s): 368 - 376
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (880 KB)  

    The paper deals with two-sensor interception of cyclostationary signals in the presence of additive non-Gaussian noise. The locally optimum approach is considered as a starting point to derive cyclostationarity-exploiting receiver structures for detecting a weak signal and locating its emission source through time-difference-of-arrival (TDOA) measurements. To obtain analytical information about th... View full abstract»

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  • Error probability calculation for multibeam Rayleigh channels

    Publication Year: 1996 , Page(s): 290 - 293
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (288 KB)  

    The error probability of wide-band signals on multibeam Rayleigh fading channels is calculated in closed form using similarity transformations of Gaussian quadratic forms. It is shown how this approach can be used to calculate the error probability on arbitrary complex Gaussian channels, even when the beams are correlated. As an application example the author considers a wide-band spread-spectrum ... View full abstract»

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  • Performance analysis of a random packet selection policy for multicast switching

    Publication Year: 1996 , Page(s): 388 - 398
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (952 KB)  

    This paper studies a random packet selection policy for multicast switching. An input packet generates a fixed number of primary copies plus a random number of secondary copies. Assuming a constant number of contending packets during a slot, the system is modeled as a discrete time birth process. A difference equation describing the dynamics of this process is derived, the solution of which gives ... View full abstract»

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  • Statistics of companding noise for QAM transmission

    Publication Year: 1996 , Page(s): 306 - 311
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (536 KB)  

    In modern voiceband data communication, the received signal is subject to nonlinear quantization noise due to companding. Under certain conditions, this quantization noise may become dominant and cause serious degradation in performance. In order to design better signal constellations for this environment, it is of interest to characterize this noise. We study the conditional probability density f... View full abstract»

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  • Performance of orthogonal multicarrier CDMA in a multipath fading channel

    Publication Year: 1996 , Page(s): 356 - 367
    Cited by:  Papers (275)  |  Patents (21)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1140 KB)  

    A new multicarrier direct sequence code-division multiple-access (DS-CDMA) system is proposed. Transmitted data bits are serial to parallel converted to a number of parallel branches. On each branch each bit is direct-sequence spread-spectrum (DS-SS) modulated and transmitted using orthogonal carriers. This procedure provides the following advantages: the transmission bandwidth is more efficiently... View full abstract»

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  • Soft information in concatenated codes

    Publication Year: 1996 , Page(s): 284 - 286
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (252 KB)  

    A new soft decision criterion is derived. This is useful in communication systems where the combination of modulation, interleaving, and error correction is used. The new algorithm is attractive to implement since traceback techniques can be used and only a little extra memory is required to obtain the soft information associated with every symbol. Furthermore, the operations involved are not recu... View full abstract»

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  • Class of majority decodable real-number codes

    Publication Year: 1996 , Page(s): 281 - 283
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (276 KB)  

    A majority decoding algorithm for a class of real-number codes is presented. Majority decoding has been a relatively simple and fast decoding technique for codes over finite fields. When applied to decode real-number codes, the robustness of the majority decoding to the presence of background noise, which is usually an annoying problem for existing decoding algorithms for real-number codes, is its... 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.

 

 

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Meet Our Editors

Editor-in-Chief
Robert Schober
University of British Columbia