• Journal of Communications and Networks
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• v.13 no.2
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• pp.167-174
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• 2011

In this paper, we propose and simulate an efficient interference cancellation scheme with an optimal ordering successive interference cancellation (SIC) algorithm for ultra wideband (UWB)/multiple-input-multiple-output (MIMO) systems in a wireless body area network (WBAN). When there are several wireless communication devices on a human body, multiple access interference (MAI) usually occurs. To mitigate the effect of MAI and achieve additional diversity gain, we utilize SIC with an optimal ordering algorithm. A zero correlation duration (ZCD) code with robust MAI capability is employed as a spread code for UWB systems in a multi-device WBAN environment. The performance of the proposed scheme is evaluated in terms of the bit error rate (BER). Simulation results confirm that the BER performance can be improved significantly if the proposed interference cancellation scheme and the ZCD code are jointly employed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3C
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• pp.304-310
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• 2009

This paper proposes a successive MAP (maximum a posteriori probability) detection scheme with SoIC(soft interference cancellation) to reduce the receiver complexity of hierarchical M-ary QAM system. For the successive MAP detection, modulation symbols generated from the other data streams are treated as Gaussian noise or eliminated as the soft interference according to their priorities. The log-likelihood ratio of the a posteriori probability (LAPRP) of each bit is calculated by the MAP detector with an adjusted noise variance in order to take the elimination and Gaussian assumption effect into account. By separating the detection process into the successive steps, the detection complexity is reduced to increase linearly with the number of bits per hierarchical M-ary QAM symbol. Simulation results show that the proposed detection provides a small performance degradation as compared to the optimal MAP detection.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3276-3292
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• 2015

Relay-assisted D2D communication extends the communication range of the D2D pairs and helps users to form D2D pairs effectively. However, due to the introduction of the multi-hop relaying, the D2D communication has to occupy extra transmission time, which may decrease the efficiency of the communication system. In this paper, we propose a scheme to make node receive D2D signal and BS signal at overlapping time to improve the spectrum efficiency according to ZigZag decoding and successive-interference-cancellation (SIC). In this way, more data can be delivered during the same duration, thus the network throughput can be further improved. Numerical results verify the performance improvement of the proposed scheme when compared with a baseline scheme. Moreover, we expand the proposed scheme from one-hop relay scenario to multi-hop relay scenario.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.432-432
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• 2004

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.428-428
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• 2004

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.10
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• pp.3-10
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• 2015

Application of polar codes to rate-adaptive asymmetric Slepian-Wolf coding is considered. We propose a method of constructing polar codes which supports rate adaptivity. The proposed polar distributed source coding with successive cancellation list decoding performs closer to the Slepian-Wolf bound than the low density parity check accumulate (LDPCA) codes in the same framework.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.550-556
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• 2016

Polar codes are one of the most favorable capacity-achieving codes due to their simple structure and low decoding complexity. However, because of the disappointing decoding performance realized using conventional successive cancellation (SC) decoders, polar codes cannot be used directly in practical applications. In contrast to conventional SC decoders, list SC (SCL) decoders with large list sizes (e.g. 32) achieve performances very close to those of maximum-likelihood (ML) decoders. In SCL decoders with large list sizes, however, hardware increase is a severe problem because an SCL decoder with list size L consists of L copies of an SC decoder. In this paper, we present a low-area SCL decoder architecture that applies the proposed merged processing element-sharing (MPES) algorithm. A merged processing element (MPE) is the basic processing unit in SC decoders, and the required number of MPEs is L(N-1) in conventional SCL decoders. Using the proposed algorithm reduces the number of MPEs by about 70% compared with conventional SCL decoders when the list size is larger than 32.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.61-66
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• 2013

In this paper, we propose an iterative soft dimension reduction based multi-input multi-output (MIMO) detection for coded spatial multiplexing system. In spite of better performance of iterative MIMO detection, its computational complexity gives a significant burden to the receivers. To mitigate this problem, we propose a scheme employing all ordering successive interference cancellation (AOSIC) for hard-decision detection and dimension reduction soft demodulator (DRSD) with iterative decoding for soft-decision detectors, respectively. This scheme can reduce complexity of iterative soft MIMO detection and provide better performance than other conventional detectors.

• International journal of advanced smart convergence
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• v.9 no.2
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• pp.68-75
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• 2020

Non-orthogonal multiple access (NOMA) has gained the significant attention in the fifth generation (5G) mobile communication, which enables the advanced smart convergence of the artificial intelligence (AI), the internet of things (IoT), and many of the state-of-the-art technologies. Recently, correlated superposition coding (SC) has been proposed in NOMA, to achieve the near-perfect successive interference cancellation (SIC) bit-error rate (BER) performance for the stronger channel users, and to mitigate the severe BER performance degradation for the weaker channel users. In the correlated SC NOMA scheme, the stronger channel user BER performance is even better than the perfect SIC BER performance, for some range of the power allocation factor. However, such excessively good BER performance is not good for the user-fairness, i.e., the more power to the weaker channel user and the less power to the stronger channel user, because the excessively good BER performance of the stronger channel user results in the worse BER performance of the weaker channel user. Therefore, in this paper, we propose the power splitting to establish the user-fairness between both users. First, we derive a closed-form expression for the power splitting factor. Then it is shown that in terms of BER performance, the user-fairness is established between the two users. In result, the power splitting scheme could be considered in correlated SC NOMA for the user-fairness.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.447-450
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• 2009

In this paper, binary pulse-antipodal modulation (2PAM) direct-sequence (DS) ultra-wideband (UWB) system is applied to multiple input multiple output (MIMO) system using vertical bell lab layered space-time (V-BLAST) structure to achieve high-data-rate communications over indoor wireless channels. The relationship between antenna dimension and BER performance of 2PAM DS UWB MIMO system is discussed. In the receiver of UWB-MIMO system, various MIMO detection algorithms such as zero-forcing (ZF), ZF-ordered successive interference cancellation (OSIC), minimum-mean-square-error (MMSE), MMSE-OSIC and maximum likelihood (ML) are comparatively studied.