xiaobei liu | Nanyang Technological University (original) (raw)
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Papers by xiaobei liu
IEEE Transactions on Information Forensics and Security, 2012
In this paper, the problem of reconstruction of the feedback polynomial in a linear scrambler is ... more In this paper, the problem of reconstruction of the feedback polynomial in a linear scrambler is studied. Our work contains two parts. In the first part, schemes to improve the performance of an existing reconstruction algorithm are proposed. Simulation results show that both the detection capability and speed of the existing algorithm are significantly improved by using our proposed schemes. In the second part, the reconstruction of linear scramblers in the presence of channel noise is investigated. We consider flipped bits due to noise as well as insertion of bits in the scrambled bit sequence. For both cases, factors which affect the performance of the reconstruction algorithm are discussed.
MILCOM 2015 - 2015 IEEE Military Communications Conference, 2015
IEEE Communications Letters, 2003
A joint source channel coding (JSCC) scheme which exploits bit-level correlation as well as symbo... more A joint source channel coding (JSCC) scheme which exploits bit-level correlation as well as symbol-level correlation efficiently in a source-controlled channel decoding (SCCD) process is proposed and applied to the mixed-excitation linear prediction (MELP) parameters of speech. A modified BCJR algorithm is also proposed for use in the SCCD algorithm. Simulation results show that our proposed scheme performs better than other redundancy-based JSCC schemes such as bit-based SCCD, soft-bit speech decoding (SBSD) and iterative source-channel decoding.
Electronics Letters, 2003
IEEE Communications Letters, 2005
A joint source-channel decoding (JSCD) scheme which exploits the combined a priori information of... more A joint source-channel decoding (JSCD) scheme which exploits the combined a priori information of source and channel in an iterative manner is proposed. A sequence minimum mean-square error (SMMSE) estimator based on bit or symbol error transition probability of the channel with memory is proposed and used in the iterative decoding process. Simulation results show that our proposed scheme leads to significant improvement over the scheme without using the a priori information of the source or channel.
IEEE Communications Letters, 2007
Joint source channel decoding (JSCD) for variable length codes (VLCs) has been shown to be effect... more Joint source channel decoding (JSCD) for variable length codes (VLCs) has been shown to be effective for errorprone channels. In this paper, we propose two schemes to enhance the performance of the existing bit-based JSCD approach for VLCs. Simulation results show that the performance of the decoder can be significantly improved, while the computational complexity is only slightly increased by using our proposed schemes.
IEEE Transactions on Communications, 2007
A simplified parallel step-by-step decoding algorithm is proposed for decoding Reed-Solomon (RS) ... more A simplified parallel step-by-step decoding algorithm is proposed for decoding Reed-Solomon (RS) codes. It uses new method to calculate the determinants of the temporarily changed syndrome matrices, based on the property of these matrices determined in this paper. By using the proposed method, the calculations of the determinants of the temporarily changed syndrome matrices become much simpler and thus the computational complexity of the step-by-step decoding algorithm is significantly reduced.
The paper presents memory-enhanced extensions of minimum mean-squared error (MMSE) decoding for v... more The paper presents memory-enhanced extensions of minimum mean-squared error (MMSE) decoding for vector quantization over noisy channels. We also develop a recursive algorithm for computing the transition probabilities of the Gilbert channel, and illustrate its performance in vector quantization of Gauss-Markov sources under noisy channel conditions. Simulation results indicate that the proposed algorithm enables the implementation of an MMSE decoder with increased robustness to channel errors.
IEEE Transactions on Information Forensics and Security, 2012
In this paper, the problem of reconstruction of the feedback polynomial in a linear scrambler is ... more In this paper, the problem of reconstruction of the feedback polynomial in a linear scrambler is studied. Our work contains two parts. In the first part, schemes to improve the performance of an existing reconstruction algorithm are proposed. Simulation results show that both the detection capability and speed of the existing algorithm are significantly improved by using our proposed schemes. In the second part, the reconstruction of linear scramblers in the presence of channel noise is investigated. We consider flipped bits due to noise as well as insertion of bits in the scrambled bit sequence. For both cases, factors which affect the performance of the reconstruction algorithm are discussed.
MILCOM 2015 - 2015 IEEE Military Communications Conference, 2015
IEEE Communications Letters, 2003
A joint source channel coding (JSCC) scheme which exploits bit-level correlation as well as symbo... more A joint source channel coding (JSCC) scheme which exploits bit-level correlation as well as symbol-level correlation efficiently in a source-controlled channel decoding (SCCD) process is proposed and applied to the mixed-excitation linear prediction (MELP) parameters of speech. A modified BCJR algorithm is also proposed for use in the SCCD algorithm. Simulation results show that our proposed scheme performs better than other redundancy-based JSCC schemes such as bit-based SCCD, soft-bit speech decoding (SBSD) and iterative source-channel decoding.
Electronics Letters, 2003
IEEE Communications Letters, 2005
A joint source-channel decoding (JSCD) scheme which exploits the combined a priori information of... more A joint source-channel decoding (JSCD) scheme which exploits the combined a priori information of source and channel in an iterative manner is proposed. A sequence minimum mean-square error (SMMSE) estimator based on bit or symbol error transition probability of the channel with memory is proposed and used in the iterative decoding process. Simulation results show that our proposed scheme leads to significant improvement over the scheme without using the a priori information of the source or channel.
IEEE Communications Letters, 2007
Joint source channel decoding (JSCD) for variable length codes (VLCs) has been shown to be effect... more Joint source channel decoding (JSCD) for variable length codes (VLCs) has been shown to be effective for errorprone channels. In this paper, we propose two schemes to enhance the performance of the existing bit-based JSCD approach for VLCs. Simulation results show that the performance of the decoder can be significantly improved, while the computational complexity is only slightly increased by using our proposed schemes.
IEEE Transactions on Communications, 2007
A simplified parallel step-by-step decoding algorithm is proposed for decoding Reed-Solomon (RS) ... more A simplified parallel step-by-step decoding algorithm is proposed for decoding Reed-Solomon (RS) codes. It uses new method to calculate the determinants of the temporarily changed syndrome matrices, based on the property of these matrices determined in this paper. By using the proposed method, the calculations of the determinants of the temporarily changed syndrome matrices become much simpler and thus the computational complexity of the step-by-step decoding algorithm is significantly reduced.
The paper presents memory-enhanced extensions of minimum mean-squared error (MMSE) decoding for v... more The paper presents memory-enhanced extensions of minimum mean-squared error (MMSE) decoding for vector quantization over noisy channels. We also develop a recursive algorithm for computing the transition probabilities of the Gilbert channel, and illustrate its performance in vector quantization of Gauss-Markov sources under noisy channel conditions. Simulation results indicate that the proposed algorithm enables the implementation of an MMSE decoder with increased robustness to channel errors.