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Joint AIC and ml decoder scheme for a space-time coded DS-CDMA system

IEICE TRANSACTIONS ON COMMUNICATIONS 2003年第8期E86B卷 2512-2516页

作者： Yi, J Lee, JH Seoul Natl Univ Sch Elect Engn & Comp Sci Seoul 151742 South Korea

In this paper, a joint adaptive interference canceller (AIC) and maximum likelihood (ml) decoder scheme is proposed for a space-time coded DS-CDMA system with the difference between arrival times from transmit antennas. As the arrival time difference causes not only ISI and MAT, but also inter-antenna interference, performance degradation in the space-time coded DS-CDMA system is more severe than that of a regular DS-CDMA system with single transmit antenna. To mitigate the effect of the interference during space-time decoding, a joint algorithm for the proposed scheme merges adaptation process of the AIC into a ml decoding algorithm. Performance of the proposed scheme is evaluated for QPSK space-time trellis codes with two transmit antennas. It is shown that the proposed scheme achieves better performance than the conventional ml decoding scheme.

关键词： DS-CDMA space-time code adaptive interference canceller ml decoder

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Iterative MIMO Effective SNR Mapping for ml decoder 82

Iterative MIMO Effective SNR Mapping for ML Decoder

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IEEE 82nd Vehicular Technology Conference (VTC Fall)

作者： Medles, Abdelkader Valadon, Cyril Mediatek Wireless Ltd Bldg 2030Cambourne Business Pk Cambridge CB23 6DW England

ISBN: (纸本)9781479980918

A new performance abstraction method for the Maximum Likelihood decoder (mlD) in the Multiple-Inputs Multiple-Outputs (MIMO) channel is presented. The method is based on a model of the iterative equalize and de-map decoder for MIMO channel and abstracts the performance of the MIMO link into a set of effective Signal-to-Noise power Ratio (SNR) values corresponding to the different streams. The proposed Iterative MIMO Effective SNR (IMES) approach is general and allows for the use of different modulation constellations and independent channel encoding on the MIMO streams. The low complexity IMES technique can be applied to different MIMO configurations and can be combined with existing approaches such as Exponential Effective SNR Mapping (EESM) and Mean Mutual Information per Bit (MMIB) - for link performance abstraction of MIMO OFDM systems. Performance results show that the proposed method delivers accurate performance abstraction across configurations with different numbers of transmit antennas and input constellation modulation orders.

关键词： MIMO ml decoder Effective SNR Link Performance Abstraction OFDM

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Iterative MIMO Effective SNR Mapping for ml decoder

Iterative MIMO Effective SNR Mapping for ML Decoder

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IEEE Vehicular Technology Conference

作者： Abdelkader Medles Cyril Valadon Mediatek Wireless Ltd Building 2030 Cambourne Business Park CB23 6DW Cambridge UK

ISBN: (纸本)9781479980925

A new performance abstraction method for the Maximum Likelihood decoder (mlD) in the Multiple-Inputs Multiple-Outputs (MIMO) channel is presented. The method is based on a model of the iterative equalize and de-map decoder for MIMO channel and abstracts the performance of the MIMO link into a set of effective Signal-to-Noise power Ratio (SNR) values corresponding to the different streams. The proposed Iterative MIMO Effective SNR (IMES) approach is general and allows for the use of different modulation constellations and independent channel encoding on the MIMO streams. The low complexity IMES technique can be applied to different MIMO configurations and can be combined with existing approaches -such as Exponential Effective SNR Mapping (EESM) and Mean Mutual Information per Bit (MMIB) - for link performance abstraction of MIMO OFDM systems. Performance results show that the proposed method delivers accurate performance abstraction across configurations with different numbers of transmit antennas and input constellation modulation orders.

关键词： MIMO ml decoder Effective SNR Link Performance Abstraction OFDM multiple input multiple output systems Orthogonal frequency division multiplexing signal to noise ratios Supernova remnants decoders transmitting antennas Iterative

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Some Connections Between Classical Coding and Network Coding Over Erroneous Cyclic Networks

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IEEE ACCESS 2016年 4卷 5889-5895页

作者： Samadi-Khaftari, Vahid Esmaeili, Morteza Gulliver, Thomas Aaron Isfahan Univ Technol Dept Math Sci Esfahan *** Iran Univ Victoria Dept Elect & Comp Engn Victoria BC V8W 2Y2 Canada

Recently, a framework was given for linear error-correcting network codes (LENCs) over cyclic networks on commutative rings. When the alphabet is considered as a rational power series ring, an LENC is referred to as a convolutional error-correcting network code (CENC). Recently, a metric was introduced for these codes based on the minimum rank distance. In this paper, a new metric is introduced for ring-based LENCs over cyclic networks based on the Hamming distance, which is referred to as the network Hamming distance. Then, some connections between maximum distance separable (MDS) LENCs and classical MDS codes are obtained. Finally, the network Hamming free distance is given for CENCs, which plays the role of the free distance for convolutional codes.

关键词： Linear error-correcting network code commutative ring network Hamming distance ml decoder free distance

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STBC Based decoders for Two-User Interference MIMO Channels

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IEICE TRANSACTIONS ON COMMUNICATIONS 2019年第9期E102B卷 1875-1884页

作者： Yi, Zhiqiang He, Meilin Pan, Peng Wang, Haiquan Hangzhou Dianzi Univ Sch Commun Engn Hangzhou Zhejiang Peoples R China

This paper analyzes the performance of various decoders in a two-user interference channel, and some improved decoders based on enhanced utilization of channel state information at the receiver side are presented. Further, new decoders, namely hierarchical constellation based decoders, are proposed. Simulations show that the improved decoders and the proposed decoders have much better performance than existing decoders. Moreover, the proposed decoders have lower decoding complexity than the traditional maximum likelihood decoder.

关键词： interference channel fading channel ml decoder hierarchical constellation performance analysis

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Evaluation of a Joint Detector Demodulator decoder (JDDD) Performance With Modulation Schemes Specified in the DVB-S2 Standard

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IEEE ACCESS 2019年 7卷 86217-86225页

作者： Chan, Kheong Sann James, Ashish Rahardja, Susanto Nanjing Inst Technol Nanjing 211167 Jiangsu Peoples R China ASTAR I2R Singapore 138632 Singapore Northwestern Polytech Univ Sch Marine Sci & Technol Xian 710072 Shaanxi Peoples R China

With the rapid increase in the growth of digital broadcast technologies, there has been a demand for high data rate, power, and bandwidth efficient transmission, which, today, is aided by the high-performing low-density parity check (LDPC) codes. In this paper, we explore a novel alternative scheme to the LDPC decoder that performs detection, demodulation, and decoding jointly, coined the joint detector demodulator decoder (JDDD). We test the JDDD through simulation using the modulation schemes defined in the DVB-S2 satellite broadcasting standard. The JDDD is a more recently developed algorithm to the sum-product algorithm (SPA) that is used in decoding the LDPC codes. The JDDD is optimal over a modulated additive white Gaussian noise/intersymbol interference (ISI) channel when resources are sufficient, with the main constraint limiting the algorithm being the availability of computing resources. In this paper, we compare the performance of the system using the JDDD against that of the LDPC decoder. The main result is that the JDDD is able to outperform the iterative detector decoder (IDD) at shorter codeword lengths, when resource requirement is smaller, while the increase in computational requirements tends to favor the IDD at longer CWLs.

关键词： Joint detector demodulator decoder map detector-demodulator iterative detector-decoder ml decoder JVDD ISI channel DVB-S2 AWGN LDPC

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Image-adaptive watermarking using maximum likelihood decoder for medical images

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MULTIMEDIA TOOLS AND APPLICATIONS 2018年第8期77卷 10303-10328页

作者： Bhinder, Preeti Singh, Kulbir Jindal, Neeru Thapar Univ Dept Elect & Commun Engn Patiala Punjab India Chitkara Univ Chitkara Univ Inst Engn & Technol Dept Elect & Commun Engn Rajpura India

In this paper, a new medical image-adaptive watermarking technique is proposed in which embedding of the watermark is done in low frequency coefficients for achieving high robustness using an adjustable dynamic strength factor. The low frequency coefficients are modeled using Gaussian distribution to design a Maximum Likelihood (ml) decoder. The decoder recovers the watermark with the help of side information containing the adjustable dynamic strength factor, position of blocks (used for embedding), mean and variances of low frequency coefficients. The method contributes towards a highly flexible and easily adjustable dynamic strength factor for achieving the best imperceptibility with the highest robustness. The validity of the new technique is verified against various attacks and the results are compared with other watermarking schemes. The proposed technique is found to generate better results.

关键词： Image-adaptive watermarking ml decoder Statistical modeling Steganography Information hiding

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A Novel Algorithm of Tail Biting Convolutional Code decoder for Low Cost Hardware Implementation

A Novel Algorithm of Tail Biting Convolutional Code Decoder ...

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International Symposium on Intelligent Signal Processing and Communication Systems (ISPACS)

作者： Ramdani, Ahmad Zaky Adiono, Trio Inst Teknol Bandung Ctr Microelect Bandung Indonesia

ISBN: (纸本)9781467364997

Tail-biting convolutional codes (TBCC) have been applied in many recent modern communication standards such as LTE and WIMAX. TBCC is a method applied in conventional convolutional code by replacing a fixed zero-tail with tail-biting data constrains to achieve a better coding efficiency. This modification makes the decoding process becomes much more complex. Due to impracticality of the optimum decoding algorithm such as brute force, recently some suboptimum algorithms have been developed but it still leaves a large amount of computation due to the iterative nature wherein the number of iterations depends on the received codeword causes inefficient system for implementation, especially for real time applications. In this paper we offer a new algorithm that is specific to low cost hardware implementation. Low cost criteria are addressed to minimum amount of computation for each decoding process. In addition to causing smaller area consumption, the lack of computing process will also make decoding processing time becomes faster. This algorithm that we call reverse trellis algorithm also offers a fixed amount of computation regardless to the received codeword, thus will not require extra memory consumption as it being on an implementation. Taking a case study on TBCC configuration for LTE, proposed algorithm requires 5712 adding operations and 3008 inverting operations. A significant decrease compared to 286736, adding 143360 inverting for Brute Force and 45079976738816 adding 1099511627776 inverting for all possible fixed tail ml decoder. In the performance of BER, reverse trellis algorithm is able to deliver improved by more than 1 dB compared to direct terminating ml decoder.

关键词： ml decoder tail-biting convolutional code bidirectional decoding low cost implementation

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Algebraic Space Time Coding in a CDMA System over a Rayleigh fading Channel

Algebraic Space Time Coding in a CDMA System over a Rayleigh...

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3rd International Conference on Information and Communication Technologies

作者： Gharsallah, Rahia Bouallegue, Ridha SUPCOM Natl Engn Sch Tunis Tel Lab 6 Tunis Tunisia SUPCOM Natl Engn Sch Sousse Tel Lab 6 Tunis Tunisia

ISBN: (纸本)9781424417513

The originality of this paper consists of combining Code Division Multiple Access (CDMA) technique with Multi Input Multi Output (MIMO) antenna system. The main objective of our contribution is to improve the capacity of the existing DS-CDMA systems by supporting an increased number of users and to achieve good performance in terms of bit error rate. This new communication scheme combining the two techniques benefit from perfect codes by employing a spectrally efficient Algebraic Space Time Coding (ASTC) and spreading spectrum by using CDMA technique equipped with Multi User Detector (MUD) that is near far resistant. In our system each user is distinguished by its spreading code signature and its unique channel impulse response (CIR) transfer function. The MIMO-CDMA system, associated by multi user detector, improves the spectral efficiency of wireless system, combat channel fading and reduce narrowband interference. The resulting is a multi-user CDMA-ASTC solution promising high speed communication for 4G cellular wireless networks. Our study and numerical results show the utility of this new wireless communication;a significant BER versus Signal to Noise Ratio (SNR) was achieved thus Multiple access interference (MAI) is suppressed and so supporting a large number of users.

关键词： Algebraic space time coding (ASTC) DS-CDMA ml decoder MMSE ZF MUD

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New Hardware-Efficient ml detection for Spatial Modulation Scheme

New Hardware-Efficient ML detection for Spatial Modulation S...

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18th IEEE International Symposium on Consumer Electronics (ISCE)

作者： Kim, Hongjoong Kim, Hojun Shang, Yulong Jung, Taejin Chonnam Natl Univ Dept ECE Kwangju South Korea

ISBN: (纸本)9781479945917

In this paper, we propose a new hardware-efficient ml decoding algorithm for a spatial modulation scheme which is basically constructed by serially concatenating maximum-ratio receive combiners with traditional slicers. With respect to complex multiplications, the new algorithm has a greatly reduced decoding complexity compared to the conventional one, especially, for higher-order modulation. This is mainly because the complexity of the slicer is practically negligible without regard to a modulation order.

关键词： Spatial Modulation MIMO MRRC ml decoder

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