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Performance evaluation of turbo and space-time turbo coded MC-CDMA downlink in single and multi-cell environments

IEICE TRANSACTIONS ON COMMUNICATIONS 2004年第10期E87B卷 3011-3020页

作者： Tsumura, S Vehkaperä, M Li, ZX Tujkovic, D Juntti, M Osaka Univ Grad Sch Engn Dept Elect Informat Syst & Energy Engn Suita Osaka 5650871 Japan Univ Oulu CWC FIN-90014 Oulu Finland

In this paper, we evaluate the performance of single- and multi-antenna multi-carrier code division multiple access (MC-CDMA) downlink (base station to mobile terminal) systems in single- and multi-cell environments. We first propose a minimum mean square error (MMSE) filter with a Gaussian approximation for a single input single output (SISO) MC-CDMA downlink system. Then, we apply it to a SIMO (single input multiple output) system with a conventional turbo coding. Furthermore, we compare the performance of SISO (1 x 1) and SIMO (1 x 2) MC-CDMA systems with that of a multiple input multiple output (MIMO) (2 x 2) system employing space-time turbo coded modulation (STruCM) in a multi-cell environment with 7 cells by computer simulation. Based on the computer simulation results, it is found that the considered MIMO system can achieve twofold capacity with the same transmission power in the multi-cell environment.

关键词： MC-CDMA MIMO MMSE space-time coding turbo coding

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The effect of the channel reliability factor in the MAP algorithm on turbo code performance in bluetooth systems

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TURKISH JOURNAL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES 2010年第2期18卷 273-279页

作者： Kahveci, Salim Kaya, Ismail Karadeniz Tech Univ Fac Engn Dept Elect & Elect Engn TR-61080 Trabzon Turkey

The effects of the channel reliability factor on the performance of turbo decoders that use a maximum a posteriori probability algorithm are investigated for wireless communication fading channels, such as Bluetooth systems. The channel reliability factor is related to the channel signal-to-noise ratio. For various values of the channel reliability factor, the obtained performance curves of the maximum a posteriori probability algorithm are given for the case of DMx Bluetooth data packets. When the channel reliability factor increases, the bit-error-rate performance of the DMx Bluetooth data packets also increases over fading channels.

关键词： turbo coding MAP algorithm channel reliability factor (L-c) bluetooth

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Comparison of coded orthogonal frequency division multiplexing and multicarrier code division multiple access systems for power line communications

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2004年第9期17卷 889-909页

作者： Katsis, PL Papadopoulos, GD Pavlidou, FN Aristotle Univ Thessaloniki Dept Telecommun Thessaloniki 54124 Greece

Orthogonal frequency division multiplexing (OFDM) and multicarrier code division multiple access (MCCDMA) systems are comparatively evaluated for power line communications (PLC) in a frequency-selective fading environment with additive coloured Gaussian noise which is used to model the actual in-home power line channel. OFDM serves as a benchmark in order to measure the performance of various MC-CDMA systems, since multicarrier modulation systems are considered the best candidate for this kind of channel. Both single-user and multi-user cases are taken into account, making use of the appropriate combiner schemes to take full advantage of each case. System efficiency is enhanced by the application of different coding techniques, a fact which shows that powerful coding can make the difference under such a hostile medium. The impact of block interleaving is investigated, while the simulation examines how different modulation schemes fair under the imposed channel conditions as well. The performance of the system is assessed by the commonly used bit error rate vs signal-to-noise ratio diagrams and there is also a comparison regarding throughput efficiency among all the tested systems. As stated in Section 4, a promising PLC application is attained. Copyright (C) 2004 John Wiley Sons, Ltd.

关键词： power line communications (PLC) orthogonal frequency division multiplexing (OFDM) multicarrier code division multiple access (MC-CDMA) turbo coding interleaving

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A study of turbo decoding with embedded AR channel model for perpendicular recording

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IEEE TRANSACTIONS ON MAGNETICS 2003年第5期39卷 2570-2572页

作者： Nakamura, Y Okamoto, Y Osawa, H Saito, H Muraoka, H Nakamura, Y Ehime Univ Fac Engn Matsuyama Ehime 7908577 Japan Tohoku Univ RIEC Sendai Miyagi 9808577 Japan

turbo decoding with an embedded autoregressive (AR) channel model is studied in an actual perpendicular magnetic recording channel. Performance of the a posteriori probability (APP) decoder is improved by applying an, AR channel model in order to estimate the decoder input sequence. The bit-error-rate (BER) performance,is obtained by read/write experiments using a spin stand with a perpendicular medium and an single-pole-type/giant magnetoresistive (SPT/GMR) head. The results show that our turbo coding and iterative decoding system using an AR channel model improves the BER performance.

关键词： autoregressive (AR) channel model iterative decoding perpendicular magnetic recording signal-dependent noise prediction turbo coding

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Channel estimation and channel tracking for correlated block-fading channels in massive MIMO systems

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Digital Communications and Networks 2018年第2期4卷 138-147页

作者： Suresh Dahiya Arun Kumar Singh Department of Electrical Engineering Indian Institute of Technology Jodhpur Rajasthan 342011 India

This paper presents a channel estimation and tracking method for correlated block-fading channels in massive MIMO wireless cellular systems. In order to conserve resources, the proposed algorithm requires the uplink pilot signal only once, at the start of communication. By utilizing the temporal correlation between consecutive Resource Blocks （RBs） and the error correction capability of turbo codes, the channel matrix in subsequent RBs is estimated at the Base Station （BS） itself using the uplink data of current the RB and the estimated channel matrix of previous the RB. Compared to existing blind estimation methods, the proposed method places fewer limitations on the system settings such as the number of BS antennas, the number of users, and the number of coherent channel usage compared to existing blind estimation methods. Simulation results show that the proposed algorithm provides better performance for a moderate RB size, a high-order of QAM scheme, and a smaller ratio of the number of BS antennas and mobile terminals （N/K）. For a reasonably small N/K （order of 10）, the proposed scheme achieves a lower symbol error probability than the conventional pilot-based estimation approach.

关键词： Massive MIMO Channel estimation Resource block turbo coding Mobile terminal

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Novel Real-Time Decision-Based Carrier Tracking for Software-Defined Radios Using M-ARY QAM Modulation

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INTERNATIONAL JOURNAL OF DECISION SUPPORT SYSTEM TECHNOLOGY 2023年第1期15卷 1-31页

作者： Marriwala, Nikhil Kousalya, Gnana C. Rajasekar, B. Nandhitha, N. M. Gautam, Ashu Sangwan, Aarti Kurukshetra Univ Univ Inst Engn & Technol Kurukshetra Haryana India St Josephs Inst Technol Chennai Tamil Nadu India Sathyabama Inst Sci & Technol Dept Elect & Commun Engn Chennai Tamil Nadu India Sathyabama Inst Sci & Technol Sch Elect & Elect Engn Chennai Tamil Nadu India GD Goenka Univ Sohna India Cent Univ Haryana Mahendergarh India

In this paper, a scalable and real-time decision-based carrier tracking for software defined radio (SDR) for M-ary QAM modulation has been proposed and tested in real-time using the universal software radio peripheral (USRP)-2922. The proposed system provides real-time decision-based carrier tracking for improved efficiency and performance. The real-time transfer of data has been done using the USRP-2922 hardware using the M-ary QAM modulation scheme for data transmission. The novelty of the proposed system is that one can transfer random data (binary bits), text or an image which can be encoded using the desired forward error correction codes (FEC) namely the convolution coding/Viterbi soft decision decoding and the turbo coding/decoding. The proposed novel SDR transceiver system with real-time decision-based carrier tracking shows an improved performance for different parameters such as the bit error rate (BER) and signal to noise ratio (Eb/No).

关键词： Bit Error Rate Convolution coding Decision-Based SDR Carrier Tracking FEC Codes Graphical User Interface M-QAM turbo coding

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Near-Capacity turbo Coded Soft-Decision Aided DAPSK/Star-QAM for Amplify-and-Forward Based Cooperative Communications

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IEEE TRANSACTIONS ON COMMUNICATIONS 2013年第3期61卷 1080-1087页

作者： Liang, Dandan Ng, Soon Xin Hanzo, Lajos Univ Southampton Commun Signal Proc & Control Res Grp Southampton SO17 1BJ Hants England

Multilevel Differential Amplitude and Phase-Shift Keying (DAPSK) schemes do not require any channel estimation, which results in low complexity. In this treatise we derive the soft-output probability formulas required for a soft-decision based demodulation of high-order DAPSK, in order to facilitate iterative detection by exchanging extrinsic information with an outer turbo Code (TC). Furthermore, when the TC block size is increased, the system operates closer to the channel capacity. Compared to the identical-throughput TC assisted 64-ary Differential Phase-Shift Keying (64-DPSK) scheme, the 4-ring based TC assisted 64-ary DAPSK arrangement has a power-efficiency improvement of 2.3 dB at a bit error rate (BER) of 10(-5). Furthermore, when the TC block size is increased, the system operates closer to the channel capacity. More specifically, when using a TC block length of 400 modulated symbols, the 64 DAPSK (4, 16) scheme is 7.56 dB away from its capacity curve, while it had a reduced gap as low as 2.25 dB, when using a longer TC block length of 40 000 modulated symbols. Finally, as a novel application example, the soft-decision M-DAPSK scheme was incorporated into an Amplify-and-Forward (AF) based cooperative communication system, which attains another 4.5 dB SNR improvement for a TC block length of 40 000 modulated symbols.

关键词： Soft-decision iterative detection DAPSK turbo coding amplify-and-forward (AF) relaying protocol correlated Rayleigh fading channel near-capacity transceivers

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Space-time turbo trellis codes for two, three, and four transmit antennas

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2004年第2期53卷 318-328页

作者： Hong, Y Yuan, JH Chen, Z Vucetic, B Univ New S Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia Univ Sydney Sch Elect & Informat Engn Sydney NSW 2006 Australia

New space-time turbo trellis codes (ST turbo TCs) with 4-phase-shift keying (PSK) and 8-PSK for two, three, and four transmit antennas in slow and fast fading channels are proposed in this paper. The component codes of the space-time turbo schemes are constructed by choosing the feedforward coefficients to maximize the minimum squared Euclidean distance and the feedback coefficients to minimize the iterative decoding threshold. The performance of the proposed ST turbo TCs with various memory orders, transmit antennas, and interleaver structures is evaluated by simulation. It is shown that the new codes achieve better performance than previously designed codes. The impact of antenna correlation and imperfect channel estimation on the code performance is also discussed.

关键词： diversity fading channels space-time (ST) coding trellis codes turbo coding

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Full-rate complex orthogonal space-time block code for multiple antennas

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WIRELESS PERSONAL COMMUNICATIONS 2007年第1期40卷 81-89页

作者： Yu, Xiangbin Xu, Dazhuan Bi, Guangguo Nanjing Univ Aeronaut & Astronaut Informat & Commun Engn Postdoctoral Res Stn Nanjing 210016 Peoples R China Southeast Univ Natl Mobile Commun Res Lab Nanjing 210096 Peoples R China

In this paper, full-rate and complex orthogonal space-time block code (STBC) schemes for multiple antennas are proposed, and turbo code is employed as channel coding to improve the proposed STBC schemes performance further. Compared with full-diversity multiple antennas STBC schemes, the proposed schemes can implement full data rate, partial diversity and a smaller complexity. On the condition of the same system throughput and concatenation of turbo code, the proposed schemes have lower bit error rate (BER) than those low-rate and full-diversity code schemes.

关键词： space-time block codes full rate multiple antennas turbo coding transmit diversity

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Adaptive Wiener-turbo systems with JPEG & bit plane compressions in image transmission

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TURKISH JOURNAL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES 2011年第1期19卷 141-155页

作者： Gose, Ersin Turkish AF Acad Dept Elect Engn TR-34149 Istanbul Turkey

In recent years, for transmission of 2D colored images over the fading channels, a new scheme has been denoted as "adaptive Wiener-turbo systems with JPEG & bit plane compressions" (AW-TSwJBC). In this paper, the performance of AW-TSwJBC is introduced over Rician and Rayleigh fading channels. We benefited from the neighborhood relation of pixels for each color plane by using a new iterative block, the "adaptive Wiener-turbo" scheme, which employs a turbo decoder, JPEG encoder/decoders, and adaptive Wiener filtering. In our approach, we could also alter compression ratios due to the importance of the image to be transferred. Based on the simulation results obtained in this study, AW-TSwJBC can recover high quality JPEG and bit plane compression images from the corresponding corrupted JPEG images at high SNR values for Rician (K = 10 dB) and Rayleigh channels. This shows the feasibility of the AW-TSwJBC approach.

关键词： Color and bit plane slicing fading channels JPEG image compression image transmission turbo coding

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