Bit-Stream-Arranged Weighted Modulation Scheme for Low Delay Spread Frequency Selective Fading Channels
Summary :
This paper proposes a bit-stream-arranged weighted modulation scheme to improve voice quality in low delay spread frequency selective fading channels. The proposed modulation scheme employs an input bit stream arrangement method that changes the bit stream order for significant bits so that they are not adjacent to each other over time; a mapping method that controls the amplitude of the modulation signals according to the importance of the bits; and modified differential encoding to prevent the error propagation from insignificant to significant bits. Computer simulations clarify that the proposed bit-stream-arranged weighted modulation scheme shows a S/N improvement of 8 dB in an 8-bit linear pulse code modulation (PCM) voice signal compared with the conventional non-weighted π/4-shift quadrature phase shift keying (QPSK) modulation scheme. The proposed scheme also shows 3. 5 dB improvement in a 4-bit adaptive differential pulse code modulation (ADPCM) voice signal. In this case, occurence of 'click noise' in recovered voice signal is halved. Although the proposed scheme increases the peak power of the modulated signals, the non-linearity of the power amplifier is not fatal.
- Publication
- IEICE TRANSACTIONS on Fundamentals Vol.E81-A No.7 pp.1452-1458
- Publication Date
- 1998/07/25
- Publicized
- Online ISSN
- DOI
- Type of Manuscript
- Special Section PAPER (Special Section on Fundamentals of Multi-dimensional Mobile Information Network)
- Category
Authors
Keyword
Latest Issue
Copyrights notice of machine-translated contents
The copyright of the original papers published on this site belongs to IEICE. Unauthorized use of the original or translated papers is prohibited. See IEICE Provisions on Copyright for details.
Cite this
Copy
Kiyoshi KOBAYASHI, Shuji KUBOTA, "Bit-Stream-Arranged Weighted Modulation Scheme for Low Delay Spread Frequency Selective Fading Channels" in IEICE TRANSACTIONS on Fundamentals,
vol. E81-A, no. 7, pp. 1452-1458, July 1998, doi: .
Abstract: This paper proposes a bit-stream-arranged weighted modulation scheme to improve voice quality in low delay spread frequency selective fading channels. The proposed modulation scheme employs an input bit stream arrangement method that changes the bit stream order for significant bits so that they are not adjacent to each other over time; a mapping method that controls the amplitude of the modulation signals according to the importance of the bits; and modified differential encoding to prevent the error propagation from insignificant to significant bits. Computer simulations clarify that the proposed bit-stream-arranged weighted modulation scheme shows a S/N improvement of 8 dB in an 8-bit linear pulse code modulation (PCM) voice signal compared with the conventional non-weighted π/4-shift quadrature phase shift keying (QPSK) modulation scheme. The proposed scheme also shows 3. 5 dB improvement in a 4-bit adaptive differential pulse code modulation (ADPCM) voice signal. In this case, occurence of 'click noise' in recovered voice signal is halved. Although the proposed scheme increases the peak power of the modulated signals, the non-linearity of the power amplifier is not fatal.
URL: https://global.ieice.org/en_transactions/fundamentals/10.1587/e81-a_7_1452/_p
Copy
@ARTICLE{e81-a_7_1452,
author={Kiyoshi KOBAYASHI, Shuji KUBOTA, },
journal={IEICE TRANSACTIONS on Fundamentals},
title={Bit-Stream-Arranged Weighted Modulation Scheme for Low Delay Spread Frequency Selective Fading Channels},
year={1998},
volume={E81-A},
number={7},
pages={1452-1458},
abstract={This paper proposes a bit-stream-arranged weighted modulation scheme to improve voice quality in low delay spread frequency selective fading channels. The proposed modulation scheme employs an input bit stream arrangement method that changes the bit stream order for significant bits so that they are not adjacent to each other over time; a mapping method that controls the amplitude of the modulation signals according to the importance of the bits; and modified differential encoding to prevent the error propagation from insignificant to significant bits. Computer simulations clarify that the proposed bit-stream-arranged weighted modulation scheme shows a S/N improvement of 8 dB in an 8-bit linear pulse code modulation (PCM) voice signal compared with the conventional non-weighted π/4-shift quadrature phase shift keying (QPSK) modulation scheme. The proposed scheme also shows 3. 5 dB improvement in a 4-bit adaptive differential pulse code modulation (ADPCM) voice signal. In this case, occurence of 'click noise' in recovered voice signal is halved. Although the proposed scheme increases the peak power of the modulated signals, the non-linearity of the power amplifier is not fatal.},
keywords={},
doi={},
ISSN={},
month={July},}
Copy
TY - JOUR
TI - Bit-Stream-Arranged Weighted Modulation Scheme for Low Delay Spread Frequency Selective Fading Channels
T2 - IEICE TRANSACTIONS on Fundamentals
SP - 1452
EP - 1458
AU - Kiyoshi KOBAYASHI
AU - Shuji KUBOTA
PY - 1998
DO -
JO - IEICE TRANSACTIONS on Fundamentals
SN -
VL - E81-A
IS - 7
JA - IEICE TRANSACTIONS on Fundamentals
Y1 - July 1998
AB - This paper proposes a bit-stream-arranged weighted modulation scheme to improve voice quality in low delay spread frequency selective fading channels. The proposed modulation scheme employs an input bit stream arrangement method that changes the bit stream order for significant bits so that they are not adjacent to each other over time; a mapping method that controls the amplitude of the modulation signals according to the importance of the bits; and modified differential encoding to prevent the error propagation from insignificant to significant bits. Computer simulations clarify that the proposed bit-stream-arranged weighted modulation scheme shows a S/N improvement of 8 dB in an 8-bit linear pulse code modulation (PCM) voice signal compared with the conventional non-weighted π/4-shift quadrature phase shift keying (QPSK) modulation scheme. The proposed scheme also shows 3. 5 dB improvement in a 4-bit adaptive differential pulse code modulation (ADPCM) voice signal. In this case, occurence of 'click noise' in recovered voice signal is halved. Although the proposed scheme increases the peak power of the modulated signals, the non-linearity of the power amplifier is not fatal.
ER -
English
