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[Keyword] peak factor(7hit)

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  • Low-Peak-Factor Pseudo-White-Noise Sequence Set with Optimal Zero-Correlation Zone

    Takafumi HAYASHI  Takao MAEDA  Shigeru KANEMOTO  Shinya MATSUFUJI  

     
    PAPER-Communication Theory and Signals

      Vol:
    E97-A No:12
      Page(s):
    2343-2351

    The present paper introduces a novel method for the construction of sequences that have a zero-correlation zone. For the proposed sequence set, both the cross-correlation function and the side lobe of the autocorrelation function are zero for phase shifts within the zero-correlation zone. The proposed scheme can generate a set of sequences, each of length 16n2, from an arbitrary Hadamard matrix of order n and a set of 4n trigonometric function sequences of length 2n. The proposed construction can generate an optimal sequence set that satisfies, for a given zero-correlation zone and sequence period, the theoretical bound on the number of members. The peak factor of the proposed sequence set is equal to √2.

  • A Class of Two-Dimensional Signal Having a Flat Power Spectrum and a Low Peak Factor

    Takafumi HAYASHI  

     
    PAPER-Digital Signal Processing

      Vol:
    E89-A No:2
      Page(s):
    494-502

    This paper presents a new generative approach for generating two-dimensional signals having both a low peak factor (crest factor) and a flat power spectrum. The flat power spectrum provides zero auto-correlation, except at the zero shift. The proposed method is a generative scheme, not a search method, and produces a two-dimensional signal of size 2(2n1+1)2(2n2+1)2 for an arbitrary pair of positive integers n1 and n2 without any computer search. The peak factor of the proposed signal is equal to the peak factor of a single trigonometric function.

  • A Construction of Low-Peak-Factor Pseudo White Noise

    Takafumi HAYASHI  

     
    LETTER-Digital Signal Processing

      Vol:
    E87-A No:12
      Page(s):
    3429-3432

    A new construction of sequences having both a low peak factor (crest factor) and flat power spectrum is proposed. The flat power spectrum provides zero auto-correlation except for the case of zero shift. The proposed construction is based on a systematic scheme that does not require a search, and affords sequences of length 4n(2n+1) for an arbitrary integer n.

  • A Class of Low-Peak-Factor Pseudo White Noise Sequence

    Takafumi HAYASHI  

     
    PAPER-Theory of Signals

      Vol:
    E87-A No:8
      Page(s):
    1850-1854

    The present report introduces a new construction of sequences having both a low peak factor (crest factor) and a flat power spectrum. Since the proposed sequence has a flat power spectrum, its auto-correlation is zero except for the zero shift. The proposed construction uses a systematic scheme and no search method. The length of the proposed sequence is (2n+1)(4n+1) for an arbitrary integer n. The sequence construction presented herein provides a means for generating various sequences at the lengths required for such applications as system measurement (which requires uncorrelated test signals), and audio signal processing for sound production (for enhancing spatial imagery in stereo signals synthesized from mono sources).

  • The Synthesis of Low-Peak Orthogonal-Base-Set Sequences Using Trigonometric Function Aliasing

    Takafumi HAYASHI  William L. MARTENS  

     
    PAPER-Theory of Signals

      Vol:
    E83-A No:8
      Page(s):
    1513-1522

    This paper presents a new technique for the synthesis of orthogonal-base-set sequences suitable for applications requiring sets of uncorrelated pseudo-white-noise sources. The synthesized sequences (vectors) are orthogonal to each other, and each sequence also has a flat power spectrum and low peak factor. In order to construct the orthogonal-base-set sequences, the new application of ta-sequence (trigonometric function aliasing sequence) introduced in this paper uses Latin-squares and Walsh-Hadamard sequences. The ta-sequence itself is a very new concept, and the method presented here provides the means for generating various orthogonal-base-set sequences at sizes required for such applications as system measurement (needing uncorrelated test signals), pseudo noise synthesis for spread spectrum communication, and audio signal processing (needing synthesis of stereo or multichannel signals from mono sources).

  • The Synthesis of Low-Peak Cross-Correlation Sequences Using Trigonometric Function Aliasing

    Takafumi HAYASHI  William L. MARTENS  

     
    PAPER

      Vol:
    E82-A No:8
      Page(s):
    1402-1411

    This paper presents a new technique for the synthesis of sets of low-peak sequences exhibiting low peak cross correlation. The sequences also have flat power spectra and are suitable for many applications requiring such sets of uncorrelated pseudo-white-noise sources. This is a new application of the ta-sequence (trigonometric function aliasing sequence), which itself is a very new technique that uses the well-known "Reed-Solomon code" or "One coincident code" to generate these sets of low-peak-factor pseudo-white-noise exhibiting low peak cross correlation. The ta sequence method presented here provides the means for generating various sequences at the lengths required for such applications as system measurement (needing uncorrelated test signals), pseudo-noise synthesis (for spread spectrum communication), and audio signal processing for sound production (for enhancing spatial imagery in stereo signals synthesized from mono sources) and sound reproduction (for controlling unwanted interference effects in multiple-loudspeaker arrays).

  • Synthesis of Low Peak-to-Peak Waveforms with Flat Spectra

    Takafumi HAYASHI  

     
    PAPER-Circuit Theory

      Vol:
    E81-A No:9
      Page(s):
    1902-1908

    This paper presents both new analytical and new numerical solutions to the problem of generating waveforms exhibiting a low peak-to-peak factor. One important application of these results is in the generation of pseudo-white noise signals that are commonly uses in multi-frequency measurements. These measurements often require maximum signal-to-noise ratio while maintaining the lowest peak-to-peak excursion. The new synthesis scheme introduced in this paper uses the Discrete Fourier Transform (DFT) to generate pseudo-white noise sequence that theoretically has a minimized peak-to-peak factor, Fp-p. Unlike theoretical works in the literature, the method presented here is based in purely discrete mathematics, and hence is directly applicable to the digital synthesis of signals. With this method the shape of the signal can be controlled with about N parameters given N harmonic components. A different permutation of the same set of offset phases of the "source harmonics" creates an entirely different sequence.