Turbo code has drawn more and more attractions for high data rate transmission these years especially in W CDMA and CDMA2000 of the third generation mobile communications systems. In this paper, the simulation perfor...Turbo code has drawn more and more attractions for high data rate transmission these years especially in W CDMA and CDMA2000 of the third generation mobile communications systems. In this paper, the simulation performance of turbo code under Rayleigh fading channel and additive white Gaussian channels are depicted. Comparison with the performance of convolutional code are made respect to different parameters, such as pilot length, interleaver size, frame length, mobile velocity and data rate, etc. Faithful results are drawn out.展开更多
A novel Joint Source and Channel Decoding (JSCD) scheme for Variable Length Codes (VLCs) concatenated with turbo codes utilizing a new super-trellis decoding algorithm is presented in this letter. The basic idea of ou...A novel Joint Source and Channel Decoding (JSCD) scheme for Variable Length Codes (VLCs) concatenated with turbo codes utilizing a new super-trellis decoding algorithm is presented in this letter. The basic idea of our decoding algorithm is that source a priori information with the form of bit transition probabilities corresponding to the VLC tree can be derived directly from sub-state transitions in new composite-state represented super-trellis. A Maximum Likelihood (ML) decoding algorithm for VLC sequence estimations based on the proposed super-trellis is also described. Simu-lation results show that the new iterative decoding scheme can obtain obvious encoding gain especially for Reversible Variable Length Codes (RVLCs),when compared with the classical separated turbo decoding and the previous joint decoding not considering source statistical characteristics.展开更多
This paper describes a new interleaver construction technique for turbo code.The technique searches as much as possible pseudo-random interleaving patterns under a certain condition using genetic algorithms(GAs).The n...This paper describes a new interleaver construction technique for turbo code.The technique searches as much as possible pseudo-random interleaving patterns under a certain condition using genetic algorithms(GAs).The new interleavers have the superiority of the S-random interleavers and this interleaver construction technique can reduce the time taken to generate pseudo-random interleaving patterns under a certain condition.The results obtained indicate that the new interleavers yield an equal to or better performance than the S-random interleavers.Compared to the S-random interleaver,this design requires a lower level of computational complexity.展开更多
A new method to design interleaver based on Henon chaos model is presented. The designed interleaver is with rather random behavior. Experimental results show that the proposed S-henon interleaver make a magnitude of ...A new method to design interleaver based on Henon chaos model is presented. The designed interleaver is with rather random behavior. Experimental results show that the proposed S-henon interleaver make a magnitude of im provement in bit error rate （BER） performance by 0.4 dB compared with the S-random interleaver for AWGN channel respectively. The S-henon interleaver may be adapted to 3G mobile communication systems.展开更多
The multilevel modulation techniques nf M-Differential Amplitude Phase Shift Keying (DAPSK) have been proposed in combination with Turbo code scheme for digital radio broadcasting bands below 30 MHz radio channel. Com...The multilevel modulation techniques nf M-Differential Amplitude Phase Shift Keying (DAPSK) have been proposed in combination with Turbo code scheme for digital radio broadcasting bands below 30 MHz radio channel. Comparison of this modulation method with channel coding in an Additive White Gaussian Noise (AWGN) and multi-path fading channels has been presented. The analysis provides an iterative decoding of the Turbo code.展开更多
Optimization of mapping rule of bit-interleaved Turbo coded modulation with 16 quadrature amplitude modulation (QAM) is investigated based on different impacts of various encoded bits sequence on Turbo decoding perfor...Optimization of mapping rule of bit-interleaved Turbo coded modulation with 16 quadrature amplitude modulation (QAM) is investigated based on different impacts of various encoded bits sequence on Turbo decoding performance. Furthermore, bit-interleaved in-phase and quadrature phase (I-Q) Turbo coded modulation scheme are designed similarly with I-Q trellis coded modulation (TCM). Through performance evaluation and analysis, it can be seen that the novel mapping rule outperforms traditional one and the I-Q Turbo coded modulation can not achieve good performance as expected. Therefore, there is not obvious advantage in using I-Q method in bit-interleaved Turbo coded modulation.展开更多
A direct detection optical orthogonal frequency division multiplexing(DDO-OFDM)system using turbo codes is built,and the transmission performance comparison between coded system and uncoded system is analyzed.Three de...A direct detection optical orthogonal frequency division multiplexing(DDO-OFDM)system using turbo codes is built,and the transmission performance comparison between coded system and uncoded system is analyzed.Three decoding algorithms,which are Log-maximum a posteriori(MAP),Max-Log-MAP and threshold Max-Log-MAP,are used in the turbo coded system.By comparing three decoding algorithms,the system using Max-Log-MAP algorithm has the best bit error rate(BER)performance.At the transmission distance of 240 km,the uncoded system with transmission rate of 30 Gbit/s can get the BER performance at the degree of 8.93×10-3 with optical signal to noise ratio(OSNR)of24 d B,while the turbo coded system with transmission rate of 50 Gbit/s can achieve it within OSNR of 20 d B.展开更多
timizing the formula, the energy for every bit of the codeword is optimized to achieve the minimum BER at high SNR region. At last, an adjustable parameter is employed to compensate the degrada- tions of BER at low an...timizing the formula, the energy for every bit of the codeword is optimized to achieve the minimum BER at high SNR region. At last, an adjustable parameter is employed to compensate the degrada- tions of BER at low and moderate SNR regions. Case studies indicate that the improvements of BER for turbo codes with short frame size are significant at a wide range of SNR展开更多
In this paper, the authors design a novel chaotic secure communication system, which has high security and good error correcting capability. Firstly, the Henon Chaos Shift Keying (CSK) modulation block is presented. S...In this paper, the authors design a novel chaotic secure communication system, which has high security and good error correcting capability. Firstly, the Henon Chaos Shift Keying (CSK) modulation block is presented. Secondly, chaotic turbo encoder/decoder (hard decision) is introduced. Thirdly, this chaotic secure communication system, which comprises the Henon CSK modulation block and chaotic turbo encoder in a serially concatenated form, is shown. Furthermore, a novel two step encryption scheme is proposed, which is based on the chaotic turbo encoded Henon CSK secure communication system.展开更多
A novel Code-Matched interleaver is proposed which decreases the number of the low weight codewords to improve the performance of the Turbo code. The modified design can adapt more kinds of Turbo codes determined by t...A novel Code-Matched interleaver is proposed which decreases the number of the low weight codewords to improve the performance of the Turbo code. The modified design can adapt more kinds of Turbo codes determined by the generator matrix, while it doesn＇t decrease the bit error rate performance of Turbo codes at moderate to high signal to noise ratio. At the same time, in Rayleigh fading channel, the new Code-Matched interleaver can also debase the error floor.展开更多
In this paper we discuss a novel storage scheme for simultaneous memory access in parallel turbo decoder. The new scheme employs vertex coloring in graph theory. Compared to a similar method that also uses unnatural o...In this paper we discuss a novel storage scheme for simultaneous memory access in parallel turbo decoder. The new scheme employs vertex coloring in graph theory. Compared to a similar method that also uses unnatural order in storage, our scheme requires 25 more memory blocks but allows a simpler configuration for variable sizes of code lengths that can be implemented on-chip. Experiment shows that for a moderate to high decoding throughput （40-100 Mbps）, the hardware cost is still affordable for 3GPP＇s （3rd generation partnership project） interleaver.展开更多
Multiple antenna wireless systems can provide larger channel capacity and enable spatial diversity to combat fading. In this paper we conduct an investigation into the design of coded space-time system obtained by ser...Multiple antenna wireless systems can provide larger channel capacity and enable spatial diversity to combat fading. In this paper we conduct an investigation into the design of coded space-time system obtained by serially concatenating channel code module and space-time code module with an interleaver in between. As an example, the system is constructed by employing low decoding complexity turbo-SPC （single parity check） code as outer module and linear complex field space-time code as inner module, which achieves full diversity and lossless equivalent channel capacity. Simulation results prove that our designed system performs well and it only loses 0.8 dB from multiple-input multiple-output （MIMO） capacity at BER = 10^-5 in the case of information bit length 6048. Compared with turbo code-based systems, it also has lower error floor.展开更多
文摘Turbo code has drawn more and more attractions for high data rate transmission these years especially in W CDMA and CDMA2000 of the third generation mobile communications systems. In this paper, the simulation performance of turbo code under Rayleigh fading channel and additive white Gaussian channels are depicted. Comparison with the performance of convolutional code are made respect to different parameters, such as pilot length, interleaver size, frame length, mobile velocity and data rate, etc. Faithful results are drawn out.
基金Supported by the National Natural Science Foundation of China (No.90304003, No.60573112, No.60272056)the Foundation Project of China (No.A1320061262).
文摘A novel Joint Source and Channel Decoding (JSCD) scheme for Variable Length Codes (VLCs) concatenated with turbo codes utilizing a new super-trellis decoding algorithm is presented in this letter. The basic idea of our decoding algorithm is that source a priori information with the form of bit transition probabilities corresponding to the VLC tree can be derived directly from sub-state transitions in new composite-state represented super-trellis. A Maximum Likelihood (ML) decoding algorithm for VLC sequence estimations based on the proposed super-trellis is also described. Simu-lation results show that the new iterative decoding scheme can obtain obvious encoding gain especially for Reversible Variable Length Codes (RVLCs),when compared with the classical separated turbo decoding and the previous joint decoding not considering source statistical characteristics.
基金Supported by the National Natural Science Foundation of China(60372057) the Key Open laboratory on Information Science and Engineering of Railway Transportation Ministry of Beijing Jiaotong University of China(KLISAE-0103)
文摘This paper describes a new interleaver construction technique for turbo code.The technique searches as much as possible pseudo-random interleaving patterns under a certain condition using genetic algorithms(GAs).The new interleavers have the superiority of the S-random interleavers and this interleaver construction technique can reduce the time taken to generate pseudo-random interleaving patterns under a certain condition.The results obtained indicate that the new interleavers yield an equal to or better performance than the S-random interleavers.Compared to the S-random interleaver,this design requires a lower level of computational complexity.
基金Supported by the National High Technology Re-search and Development Program of China(2001AA123053)
文摘A new method to design interleaver based on Henon chaos model is presented. The designed interleaver is with rather random behavior. Experimental results show that the proposed S-henon interleaver make a magnitude of im provement in bit error rate （BER） performance by 0.4 dB compared with the S-random interleaver for AWGN channel respectively. The S-henon interleaver may be adapted to 3G mobile communication systems.
基金Supported by the National Natural Science Foundation of China (No.60072013)
文摘The multilevel modulation techniques nf M-Differential Amplitude Phase Shift Keying (DAPSK) have been proposed in combination with Turbo code scheme for digital radio broadcasting bands below 30 MHz radio channel. Comparison of this modulation method with channel coding in an Additive White Gaussian Noise (AWGN) and multi-path fading channels has been presented. The analysis provides an iterative decoding of the Turbo code.
文摘Optimization of mapping rule of bit-interleaved Turbo coded modulation with 16 quadrature amplitude modulation (QAM) is investigated based on different impacts of various encoded bits sequence on Turbo decoding performance. Furthermore, bit-interleaved in-phase and quadrature phase (I-Q) Turbo coded modulation scheme are designed similarly with I-Q trellis coded modulation (TCM). Through performance evaluation and analysis, it can be seen that the novel mapping rule outperforms traditional one and the I-Q Turbo coded modulation can not achieve good performance as expected. Therefore, there is not obvious advantage in using I-Q method in bit-interleaved Turbo coded modulation.
基金supported by the National Natural Science Foundation of China(No.61107052)the Tianjin Natural Science Foundation of China(No.11JCYBJC0010)the Tianjin Youth Foundation of China(No.13JCQNJC01800)
文摘A direct detection optical orthogonal frequency division multiplexing(DDO-OFDM)system using turbo codes is built,and the transmission performance comparison between coded system and uncoded system is analyzed.Three decoding algorithms,which are Log-maximum a posteriori(MAP),Max-Log-MAP and threshold Max-Log-MAP,are used in the turbo coded system.By comparing three decoding algorithms,the system using Max-Log-MAP algorithm has the best bit error rate(BER)performance.At the transmission distance of 240 km,the uncoded system with transmission rate of 30 Gbit/s can get the BER performance at the degree of 8.93×10-3 with optical signal to noise ratio(OSNR)of24 d B,while the turbo coded system with transmission rate of 50 Gbit/s can achieve it within OSNR of 20 d B.
基金Supported by the National High Technology Research and Development Programme of China(No.2014AA01A705)the National Natural Science Foundation of China(U1204607)
文摘timizing the formula, the energy for every bit of the codeword is optimized to achieve the minimum BER at high SNR region. At last, an adjustable parameter is employed to compensate the degrada- tions of BER at low and moderate SNR regions. Case studies indicate that the improvements of BER for turbo codes with short frame size are significant at a wide range of SNR
文摘In this paper, the authors design a novel chaotic secure communication system, which has high security and good error correcting capability. Firstly, the Henon Chaos Shift Keying (CSK) modulation block is presented. Secondly, chaotic turbo encoder/decoder (hard decision) is introduced. Thirdly, this chaotic secure communication system, which comprises the Henon CSK modulation block and chaotic turbo encoder in a serially concatenated form, is shown. Furthermore, a novel two step encryption scheme is proposed, which is based on the chaotic turbo encoded Henon CSK secure communication system.
文摘A novel Code-Matched interleaver is proposed which decreases the number of the low weight codewords to improve the performance of the Turbo code. The modified design can adapt more kinds of Turbo codes determined by the generator matrix, while it doesn＇t decrease the bit error rate performance of Turbo codes at moderate to high signal to noise ratio. At the same time, in Rayleigh fading channel, the new Code-Matched interleaver can also debase the error floor.
基金supported by the National High-Technology Research and Development Program of China （Grant No.2003AA123310）, and the National Natural Science Foundation of China （Grant Nos.60332030, 60572157）
文摘In this paper we discuss a novel storage scheme for simultaneous memory access in parallel turbo decoder. The new scheme employs vertex coloring in graph theory. Compared to a similar method that also uses unnatural order in storage, our scheme requires 25 more memory blocks but allows a simpler configuration for variable sizes of code lengths that can be implemented on-chip. Experiment shows that for a moderate to high decoding throughput （40-100 Mbps）, the hardware cost is still affordable for 3GPP＇s （3rd generation partnership project） interleaver.
基金supported by the National Natural Science Foundation of China （Grant Nos.60332030, 60572157）, and the National High-TechnologY Research and Development of China （Grant No.863-2003AA123310）
文摘Multiple antenna wireless systems can provide larger channel capacity and enable spatial diversity to combat fading. In this paper we conduct an investigation into the design of coded space-time system obtained by serially concatenating channel code module and space-time code module with an interleaver in between. As an example, the system is constructed by employing low decoding complexity turbo-SPC （single parity check） code as outer module and linear complex field space-time code as inner module, which achieves full diversity and lossless equivalent channel capacity. Simulation results prove that our designed system performs well and it only loses 0.8 dB from multiple-input multiple-output （MIMO） capacity at BER = 10^-5 in the case of information bit length 6048. Compared with turbo code-based systems, it also has lower error floor.
