Proceedings ArticleDOI
Adaptive modulation system with punctured convolutional code for high quality personal communication systems
Hidehiro Matsuoka,Seiichi Sampei,Norihiko Morinaga,Yukiyoshi Kamio +3 more
- pp 22-26
TLDR
In this article, an adaptive modulation system with a punctured convolutional code for land mobile communications is proposed to achieve high quality, high bit rate, and high spectral efficient data transmission in multipath fading environments.Abstract:
This paper proposes an adaptive modulation system with a punctured convolutional code for land mobile communications to achieve high quality, high bit rate, and high spectral efficient data transmission in multipath fading environments. The proposed system adaptively controls the coding rate of the punctured convolutional code, symbol rate, and modulation level according to the instantaneous fading channel conditions. The performance in fading environments is evaluated theoretically and by computer simulation. The results show that the proposed system can realize higher quality transmission without the degradation in average bit rate compared to conventional adaptive modulation systems.read more
Citations
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Proceedings ArticleDOI
Adaptive modulation system with variable coding rate concatenated code for high quality multi-media communication systems
TL;DR: An adaptive modulation system with a concatenated code (AMS-CC) for land mobile communications to achieve high quality, high bit rate transmission in Rayleigh fading environments is proposed.
Patent
Transceiver apparatus and method for efficient high-speed data retransmission and decoding in a CDMA mobile communication system
TL;DR: In this paper, a method for retransmitting coded bits by a transmitter in response to a retransmission request from a receiver in a mobile communication system which separates coded bits output from an encoder into coded bits with higher priority and coded bit with lower priority, and transmits from the transmitter to the receiver a stream of symbols obtained by symbol mapping the coded bits of the selected sub-packets by a specific modulation technique, with the determined available orthogonal codes.
Journal ArticleDOI
Variable rate adaptive modulation for DS-CDMA
Vincent K. N. Lau,S.V. Maric +1 more
TL;DR: It is found that adaptive coding scheme is relatively robust to shadowing, while fix-rate codes are ineffective in the shadowing environment and is found to be robust to mobile speed, feedback delay, and finite interleaving depth.
Patent
Systems and methods for communicating spread spectrum signals using variable signal constellations
TL;DR: In this article, an error correction encoder that encodes bitstream according to a selected error correction code of a plurality of selectable error correction codes is described. And the spreader includes a variable spreader that spreads the symbol according to an orthogonal spreading code, including at least two spreading codes of different lengths.
Journal ArticleDOI
Channel capacity and error exponents of variable rate adaptive channel coding for Rayleigh fading channels
TL;DR: It is shown that the variable rate scheme can only increase the channel error exponent and the optimal rate control rules are found for Rayleigh fading channels with feedback of channel states.
References
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Journal ArticleDOI
High-Rate Punctured Convolutional Codes for Soft Decision Viterbi Decoding
Y. Yasuda,K. Kashiki,Y. Hirata +2 more
TL;DR: The high-rate punctured codes of rates 2/3 through 13/14 are derived from rate 1/2 specific convolutional codes with maximal free distance based on their bit error rate performances under soft decision Viterbi decoding.
Journal ArticleDOI
Rayleigh fading compensation for QAM in land mobile radio communications
S. Sampei,T. Sunaga +1 more
TL;DR: It is demonstrated by computer simulation and laboratory experiments that the pilot symbol-aided fading compensation can sufficiently compensate for fast varying Rayleigh fading, and 16-QAM gives the highest spectral efficiency in the case of cellular systems.
Journal ArticleDOI
Adaptive trellis-coded multiple-phase-shift keying for Rayleigh fading channels
TL;DR: It is shown that ATCMPSK results in considerable improvement in bit-error-rate (BER) performance of MPSK signals, and gains in the range of 3-20 dB are achieved over conventional fixed rate pragmatic trellis-coded schemes.
Proceedings ArticleDOI
Symbol rate and modulation level controlled adaptive modulation/TDMA/TDD for personal communication systems
TL;DR: Computer simulation confirms that the proposed system can achieve higher bit rate transmission with higher quality in both flat Rayleigh and frequency selective fading environments.
Journal ArticleDOI
The effects of multipath delay spread on timing recovery
TL;DR: In this paper, the authors derived the recovered timing for a squaring timing recovery circuit under multipath radio propagation and derived an expression for the recovery time for coherent and differential detections.