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IEEE Global Communications Conference

作者： Yi Liu Xiang-Gen Xia Zhiqiang Zhang Hailin Zhang State Key Laboratory of Integrated Service Network Xidian University Department of Electrical and Computer Engineering University of Delaware

ISBN: (纸本)9781479959532

In this paper, we consider two-way full-duplex (FD) relay networks, which allow relaying communications in both directions at the same time and over the same frequency band. We propose a distributed space-time coding scheme, which we call SC-DSTC (Self-Coded Distributed Space-Time coding), where the main idea is to perform convolutional encoding at the relay node and form a distributed linear convolutional space-time code (DLC-STC) together with the direct link. The convolutional code at the relay is realized by using part of the residual loop interference (RLI), which produces an automatic convolutional encoder. The amplifying factor is optimized when the loop channel information is imperfect. Simulation results show that the proposed SC-DSTC scheme can achieve asynchronous full cooperative diversity and is robust to the error of the loop channel information.

关键词： time coding space-time coding differential space-time coding Trunk Node Relay networks FULL DUPLEX convolutional coding Distribute Bidirectional relay

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Error probabilities of frequency-hopped MFSK with self-normalization combining in a fading channel with partial-band interference

Error probabilities of frequency-hopped MFSK with self-norma...

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作者： Michael W. Briske Naval Postgraduate School

学位级别：硕士

Research entails derivation of statistical description of output from an MFSK receiver which uses self-normalization of the output from quadratic detectors. The system uses fast frequency hopping to provide diversity and assumes independent channels for each hop when the signal is recombined. The effects of fading channels are investigated for both Rayleigh and Rician fading channel descriptions. Probability of bit error for the uncoded performance is plotted for various signal-mt-noike ratin.% (SNR) and different levels of diversity versus worst-case partial-band jamming. Analysis for Forward Error Correction coding is included for rate 1/2 and 1/3 convolutional codes and (n, k) Reed-Solomon Block codes. Probability of bit error is plotted for each code with various signal-to-noise ratios and diversity levels I to 4 versus worst-case partial-band jamming.

关键词： MFSK self-normalization receiver Reed-Solomon coding convolutional coding fading path partial-band interference

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IMPROVING ERROR PERFORMANCE IN BANDWIDTH-LIMITED BASEBAND CHANNELS

IMPROVING ERROR PERFORMANCE IN BANDWIDTH-LIMITED BASEBAND CH...

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作者： Juan W. Alfaro Zavala University of Gavle

学位级别：硕士

Channel coding has been largely used for the purpose of improving error performance on a communications system. Typical methods based on added redundancy allow for error detecti and correction, this improvement however comes at a cost of bandwidth. This thesis focuses on channel coding for the bandwidth-limited channel where no bandwidth expansion is allowed. We first discuss the idea of coding for the bandwidth-limited channel as seen from the signal space point of view where the purpose of coding is to maximize the Euclidian distance between constellation points without increasing the total signal power and under the condition that no extra bits can be added. We then see the problem from another angle and identify the tradeoffs related to bandwidth and error performance. This thesis intends to find a simple way of achieving an improvement in error performance for the bandwidth-limited channel without the use of lattice codes or trellis-coded modulation. The proposed system is based on convolutional coding followed by multilevel transmission. It achieved a coding gain of 2 dB on or equivalently, a coding gain of approximately 2.7 dB on without increase in bandwidth. This coding gain is better than that obtained by a more sophisticated lattice code Gosset E 8 at the same error rate.

关键词： Channel coding bandwidth-limited channel band-limited channel error performance BER lattice codes trellis-coded modulation TCM convolutional coding multilevel transmission soft decisions hard decisions MPAM

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Design of a ZigBee Based WSN with Channel coding for Energy and Temperature Monitoring

Design of a ZigBee Based WSN with Channel Coding for Energy ...

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Al-Sadeq International Conference on Multidisciplinary in IT and Communication Science and Applications

作者： Hikmat N. Abdullah Tariq M. Salman Haider A. H. Alobaidy College of Information Engineering University of Al-Nahrain Department of Electrical Engineering College of Engineering Al-Mustansiriya University

ISBN: (纸本)9781509032488

This paper has two objectives. First, to design and implement a prototype of WSN for monitoring power as well as temperature in buildings. Second, to evaluate the amount of improvement introduced to the ZigBee transceiver when channel-coding method is used. The results indicated that the use of ZigBee based WSN in electric power monitoring provides flexibility and helps in reducing power consumption. Furthermore, the simulation results show that using convolutional coding (CC) in ZigBee transceiver gives better performance compared to traditional ZigBee transceivers specially at CC of code rate 1/8.

关键词： Wireless Sensor Network (WSN) ZigBee IEEE 802.15.4 convolutional coding Automation Monitoring

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Error probabilities of FFH/BFSK with noise normalization and soft decision Viterbi decoding in a fading channel with partial-band jamming

Error probabilities of FFH/BFSK with noise normalization and...

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作者： Chua, Anthony Y. P. NAVAL POSTGRADUATE SCHOOL

学位级别：硕士

An error probability analysis of a communications link employing convolutional coding with soft decision Viterbi decoding implemented on a fast frequency-hopped, binary frequency-shift keying (FFH/BFSK) spread spectrum system is performed. The signal is transmitted through a frequency non-selective, slowly fading channel with pa1tial-band jamming. Noise nomialization combining is employed at the receiver to alleviate the effects of par'tial-band jamming. The received signal amplitude of each hop is modeled as a Rician process, and each hop is assumed to fade independently. It is found that with the implementation of soft decision Viterbi decoding that the performance of the receiver is improved dramatically when the coded bit energy to partial-band noise power spectral density ratio (Eb/N1) is greater than 10dB. At higher Eb/NI, the asymptotic error improves dramatically and vanes from 105 to 10'" depending on the constraint length (V), number of hops/bit (L), and the strength of the direct signal (012/202). In addition, nearly worst case jamming occurs when lhe jammer uses a full band jamming strategy, even when L: l and there is a very strong direct signal (Q2/203 = I00). Due to non-coherent combining losses, when the hop per bit ratio is increased, there is some degradation at moderate Eb/NI. Furthermore, when a stronger code is used (ie., the constraint length is longer), performance improves, especially for high ED/N, where the asymptotic error is reduced. Finally, soft decision decoding improves performance over hard decision decoding from 4 to 8dB at moderate Eb/N, depending on the code rate and with a much lower asymptotic error at high Eb/N1.

关键词： fast frequency hopping noise normalization convolutional coding

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Mit :: Lcs :: Tm :: Mit-Lcs-Tm-547

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2016年

Mit :: Lcs :: Tm :: Mit-Lcs-Tm-547 by published by

关键词： base station bits burst channel coding coding convolutional convolutional coding gsm gsm system interleaving mit-lcs-tm-547 mobile station modulation radio waves speech tdma tdma frame time slot transmission aspects viterbi viterbi decoder

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Performance Analysis of Dispersed Spectrum Cognitive Radio Systems

Performance Analysis of Dispersed Spectrum Cognitive Radio S...

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作者： Mohammad, Muneer Texas A&M University

Dispersed spectrum cognitive radio systems represent a promising approach to exploit the utilization of spectral resources to full extent. Therefore, the performance analysis of such systems is conducted in this research. The Average symbol error probability of dispersed spectrum cognitive radio systems is derived for two cases: where each channel realization experiences independent and dependent Nakagami-m fading, respectively. In addition, the derivation is extended to include the effects of modulation type and order by considering M-PSK and M-QAM modulation schemes. We then study the impacts of topology on the effective transport capacity performance of ad hoc dispersed spectrum cognitive radio systems where the nodes assume 3- dimensional (3D) configurations. We derive the effective transport capacity considering a cubic grid distribution. In addition, numerical results are presented to demonstrate the effects of topology on the effective transport capacity of ad hoc dispersed cognitive radio systems.

关键词： Dispersed Spectrum Cognitive Radio Frequency Diversity M-QAM M-PSK convolutional coding Adhoc Effective transport capacity Book Thesis

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Research and Implementation of Viterbi Decoding in TD-LTE System

Research and Implementation of Viterbi Decoding in TD-LTE Sy...

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2017 IEEE 第2届先进信息技术,电子与自动化控制国际会议(IAEAC 2017)

作者： Li Li-fu Li Hai-wen Li Hong-liang Gu Yong-jun Chongqing Communication Institute Zhengzhou Information Science and Technology Institute

The Viterbi algorithms of the tail biting convolutional code in TD-LTE system is introduced. Aiming at the decoding commons for the convolutional codes of TD-LTE system, this paper presents an impleme

ISBN: (纸本)9781467389808

关键词： Tail biting convolutional code Soft-decision Viterbi decoding Viterbi decoding soft decision convolutional coding Viterbi algorithm DEcoding Simulation results

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Concatenated coding scheme with variable coding gain

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Electronics and Communications in Japan (Part III: Fundamental Electronic Science) 1993年第3期76卷 91-104页

作者： Kojima, Toshiharu Fujimura, Akinori Miyake, Makoto Fujino, Tadashi Yoshida, Hideo Yamagishi, Atsuhiro Communication Systems Laboratory Mitsubishi Electric Corporation Kamakura 247 Japan Computer and Information Systems Laboratory Mitsubishi Electric Corporation Kamakura 247 Japan

The concatenated coding scheme using convolutional coding with Viterbi decoding for inner code and Reed‐Solomon (RS) code for outer codes is an attractive scheme that can achieve a coding gain larger than that of the convolutional coding with the Viterbi decoding scheme. Hence, it has attracted attention in a wide range of fields in satellite communications from space communications to digital image transmission systems. This paper presents the configuration and characteristics of a newly developed concatenated coding scheme with variable coding gain. This scheme enables selection of a coding gain considering the signal processing time of coding and decoding by enabling selection of: 1) the block length of the RS code (and its error‐correction capability);2) the depth of interleaving combining the inner and outer code by a single codec. In addition, in this scheme, a new synchronization word detection method was developed and employed. In this method, nonlinear conversion is applied to soft decision demodulated data to synchronize the RS codeword and interleaving. It has been confirmed by numerical calculations that this synchronization word detection method has characteristics further improved over those of the conventional soft decision synchronization word detection method which is superior to the hard decision method. An experimental system was developed and the field test via Ka‐band satellite of communication satellite No. 3 (CS‐3) was performed, and the tradeoff relationships between the coding/decoding signal processing time and coding gain have been clarified quantitatively. Copyright © 1993 Wiley Periodicals, Inc., A Wiley Company

关键词： Concatenated code convolutional coding Reed‐Solomon code synchronization word detection Viterbi decoding

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convolutional coded generalized nonlinear CPM

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 1998年第8期81卷 42-50页

作者： Shinoi, K Wibisono, G Sasase, I Keio Univ Dept Elect Engn Yokohama Kanagawa 223 Japan

Continuous phase modulation (CPM) is known for its attractive spectral properties. Furthermore, CPM has the property that the modulation signal maintains a Constant envelope, so CPM is effective for satellite communications. Recently, generalized nonlinear CPM (GNCPM), which can achieve a larger minimum Euclidean distance than ordinary CPM, was introduced. In this paper, we propose a convolutional coded GNCPM to improve the bit error rate (BER) performance of uncoded GNCPM without expanding bandwidth. Combination CPM with convolutional coding causes an increased number of phase trajectory patterns which can cause the bandwidth expansion. Therefore, in our proposed model, to control the bandwidth, we pay attention to the phase trajectory pattern which is already owned by:uncoded GNCPM and change the modulation index approximately, depending on the input symbols, to keep the number of phase trajectory patterns the same as in uncoded GNCPM. First, we consider the most suitable assignment of the modulation index which can increase the Euclidean distances without bandwidth expansion. Next, we theoretically derive the upper bound on the error event probability of the proposed model in additive white Gauss lan noise (AWGN). The performance of the proposed convolutional GNCPM, obtained by computer simulation, shows that the proposed model can improve BER performance without bandwidth expansion. (C) 1998 Scripta Technica.

关键词： continuous phase modulation convolutional coding modulation index minimum Euclidean distance

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