In this paper,an efficient unequal error protection(UEP)scheme for online fountain codes is proposed.In the buildup phase,the traversing-selection strategy is proposed to select the most important symbols(MIS).Then,in...In this paper,an efficient unequal error protection(UEP)scheme for online fountain codes is proposed.In the buildup phase,the traversing-selection strategy is proposed to select the most important symbols(MIS).Then,in the completion phase,the weighted-selection strategy is applied to provide low overhead.The performance of the proposed scheme is analyzed and compared with the existing UEP online fountain scheme.Simulation results show that in terms of MIS and the least important symbols(LIS),when the bit error ratio is 10-4,the proposed scheme can achieve 85%and 31.58%overhead reduction,respectively.展开更多
In order to improve the video transmission performance in Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing （MIMO-OFDM） system, a new scheme, which integrates Multiple Description Coding （MD...In order to improve the video transmission performance in Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing （MIMO-OFDM） system, a new scheme, which integrates Multiple Description Coding （MDC）, Low Density Parity Check （LDPC） coding and hybrid space time coding, is proposed in this letter. In particular, a hybrid space time coding algorithm is combined with LDPC codes to perform Unequal Error Protection （UEP） of MDC encoded video streams. Comparing with the UEP transmission with only LDPC codes, the proposed scheme achieves more than ldB gain in terms of Signal to Noise Ratio （SNR） when the Peak Signal to Noise Ratio （PSNR） of reconstructed video is above 30dB.展开更多
在多媒体数据传输中,重要数据对可靠性要求比较高,在较差信道条件下需要更强的保护,为此提出了一种具有不等保护能力的级联型UEP-LT码方案。该方案先对重要比特(More Important Bits,MIB)数据进行预编码,并引入扩展窗技术进行优化设计,...在多媒体数据传输中,重要数据对可靠性要求比较高,在较差信道条件下需要更强的保护,为此提出了一种具有不等保护能力的级联型UEP-LT码方案。该方案先对重要比特(More Important Bits,MIB)数据进行预编码,并引入扩展窗技术进行优化设计,然后利用And-Or树分析法对误码率性能进行分析。仿真结果表明,基于扩展窗的级联型UEP-LT码增强了对MIB数据的保护程度,并且降低了对次重要比特(Less Important Bits,LIB)性能的损失,具有良好的UEP特性。展开更多
To enhance encoding efficiency, an unequal error protection （UEP） broadcast scheme based on one additional feedback is proposed. Different from the equal probability selection for source packets in traditional fount...To enhance encoding efficiency, an unequal error protection （UEP） broadcast scheme based on one additional feedback is proposed. Different from the equal probability selection for source packets in traditional fountain encoding, the proposed scheme calculates the packet loss ratio （PLR） according to the feedback results in systematic broadcast phase （SBP） and then optimizes the selection probability for source packets to guarantee higher level error protection for those source packets with larger PLRs. Thus the amount of unnecessarily redundant encoded packets during encoding broadcast phase （EBP） is decreased significantly. Numerical results show that the proposed scheme can recover 60% more packets than the traditional non-feedback broadcast scheme at the ex- pense of tolerably only one feedback procedure.展开更多
An enhanced scheme is proposed for high code rate low density parity check （LDPC） coded partial incremental redundancy （PIR） hybrid automatic repeat request （HARQ）. It employs the unequal error protection （UEP...An enhanced scheme is proposed for high code rate low density parity check （LDPC） coded partial incremental redundancy （PIR） hybrid automatic repeat request （HARQ）. It employs the unequal error protection （UEP） technique for incremental redundancy bits and uses the constellation rearrangement （CoRe） technique for information bits in retransmissions so as to reduce the reliability variances of all encoded bits after soft combining. Simulation results show that the proposed scheme applies to both regular LDPC and irregular LDPC cases and can efficiently improve frame error rate （FER） performance and throughput performance.展开更多
Stereo video is widely used because it can provide depth information. However, it is difficult to store and transmit stereo video due to the huge data amount. So, high efficient channel encoding algorithm and proper t...Stereo video is widely used because it can provide depth information. However, it is difficult to store and transmit stereo video due to the huge data amount. So, high efficient channel encoding algorithm and proper transmission strategy is needed to deal with the video transmission over limited bandwidth channel. In this paper, unequal error protection (UEP) based on low density parity check (LDPC) code was used to transmit stereo video over wireless channel with limited bandwidth. Different correction level LDPC code was used according to the importance of video stream to reconstruction at the receiver. Simulation result shows that the proposed transmission scheme increases the PSNR of reconstructed image, and improves the subjective effect.展开更多
This paper described a signal processor for the Reed-Solomon (R-S) code using micro-programming. For the purpose of fast encoding and decoding,a formula for detecting two errors is derived, and the Qian search method...This paper described a signal processor for the Reed-Solomon (R-S) code using micro-programming. For the purpose of fast encoding and decoding,a formula for detecting two errors is derived, and the Qian search method for the decoding process is improved. The number of searches is significantly reduced from 256 to 4. At the same time, the circuit is simplified and the speed is increased. For the convenience of programming, a micro-programming compiling package is developed. The package can be used for programming of different formats of R-S code signal processors of DAB, MD and DCC. The software and the hardware can be used for error correcting, error detecting and error compensation of different formats of R-S code.展开更多
The Enhanced Variable Rate Codec (EVRC) is a standard for the Speech Service Option 3 for Wideband Spread Spectrum Digital System, which has been employed in both IS-95 cellular systems and ANSI J-STC-008 PCS (Persona...The Enhanced Variable Rate Codec (EVRC) is a standard for the Speech Service Option 3 for Wideband Spread Spectrum Digital System, which has been employed in both IS-95 cellular systems and ANSI J-STC-008 PCS (Personal Communications Systems). This paper investigated the combination of turbo codes with Unequal Error Protection (UEP) and 16-QAM modulation for EVRC codec of Rate 1 to get power and bandwidth efficient coding scheme. The results show that the UEP system outperforms the Equal Error Protection (EEP) one by 1.45 dB at BER of 10 -5.展开更多
Based on the property that high degree variable nodes within an irregular LowDensity Parity-Check (LDPC) code have more powerful error-correcting capability than that of low degree variable nodes, a group of irregular...Based on the property that high degree variable nodes within an irregular LowDensity Parity-Check (LDPC) code have more powerful error-correcting capability than that of low degree variable nodes, a group of irregular LDPC codes with Unequal Error Protection (UEP)property is designed in this letter. Simulation results show that the transmission quality of the image may be effectively improved with this class of irregular LDPC code.展开更多
为了提高MLC NAND Flash的抗误码性能,该文提出一种基于优化缩短极化码的MLC NAND Flash差错控制方法。优化缩短极化码通过优化删减图样得到,首先通过比特翻转重排序的方式得到基本删减图样,进而选择具有更低信道容量的冻结比特组成优...为了提高MLC NAND Flash的抗误码性能,该文提出一种基于优化缩短极化码的MLC NAND Flash差错控制方法。优化缩短极化码通过优化删减图样得到,首先通过比特翻转重排序的方式得到基本删减图样,进而选择具有更低信道容量的冻结比特组成优化删减图样,使得到的删减比特全为冻结比特,可以显著提高删减算法的纠错性能。同时,根据MLC单元错误的不对称性,采用码率自适应的码字对FLASH中MSB和LSB进行不等错误保护。仿真结果表明:当误帧率为310-时,优化缩短极化码较相同码长的LDPC码和基本缩短极化码分别约有3.72~5.89 d B和1.47~3.49 d B增益;相比基于同一码率的优化缩短极化码方案,不等错误保护的差错控制方案获得约0.25 d B增益。展开更多
基金supported by the National Natural Science Foundation of China(61601147)the Beijing Natural Science Foundation(L182032)。
文摘In this paper,an efficient unequal error protection(UEP)scheme for online fountain codes is proposed.In the buildup phase,the traversing-selection strategy is proposed to select the most important symbols(MIS).Then,in the completion phase,the weighted-selection strategy is applied to provide low overhead.The performance of the proposed scheme is analyzed and compared with the existing UEP online fountain scheme.Simulation results show that in terms of MIS and the least important symbols(LIS),when the bit error ratio is 10-4,the proposed scheme can achieve 85%and 31.58%overhead reduction,respectively.
基金the National Natural Science Foundation of China (No. 60328103).
文摘In order to improve the video transmission performance in Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing （MIMO-OFDM） system, a new scheme, which integrates Multiple Description Coding （MDC）, Low Density Parity Check （LDPC） coding and hybrid space time coding, is proposed in this letter. In particular, a hybrid space time coding algorithm is combined with LDPC codes to perform Unequal Error Protection （UEP） of MDC encoded video streams. Comparing with the UEP transmission with only LDPC codes, the proposed scheme achieves more than ldB gain in terms of Signal to Noise Ratio （SNR） when the Peak Signal to Noise Ratio （PSNR） of reconstructed video is above 30dB.
文摘在多媒体数据传输中,重要数据对可靠性要求比较高,在较差信道条件下需要更强的保护,为此提出了一种具有不等保护能力的级联型UEP-LT码方案。该方案先对重要比特(More Important Bits,MIB)数据进行预编码,并引入扩展窗技术进行优化设计,然后利用And-Or树分析法对误码率性能进行分析。仿真结果表明,基于扩展窗的级联型UEP-LT码增强了对MIB数据的保护程度,并且降低了对次重要比特(Less Important Bits,LIB)性能的损失,具有良好的UEP特性。
基金Supported by China National S&T Major Project(2013ZX03003002003)the National Natural Science Foundation of China(61371075)"111"Project of China(B14010)
文摘To enhance encoding efficiency, an unequal error protection （UEP） broadcast scheme based on one additional feedback is proposed. Different from the equal probability selection for source packets in traditional fountain encoding, the proposed scheme calculates the packet loss ratio （PLR） according to the feedback results in systematic broadcast phase （SBP） and then optimizes the selection probability for source packets to guarantee higher level error protection for those source packets with larger PLRs. Thus the amount of unnecessarily redundant encoded packets during encoding broadcast phase （EBP） is decreased significantly. Numerical results show that the proposed scheme can recover 60% more packets than the traditional non-feedback broadcast scheme at the ex- pense of tolerably only one feedback procedure.
基金Sponsored by the National Natural Science Foundation of China(60502026)
文摘An enhanced scheme is proposed for high code rate low density parity check （LDPC） coded partial incremental redundancy （PIR） hybrid automatic repeat request （HARQ）. It employs the unequal error protection （UEP） technique for incremental redundancy bits and uses the constellation rearrangement （CoRe） technique for information bits in retransmissions so as to reduce the reliability variances of all encoded bits after soft combining. Simulation results show that the proposed scheme applies to both regular LDPC and irregular LDPC cases and can efficiently improve frame error rate （FER） performance and throughput performance.
文摘Stereo video is widely used because it can provide depth information. However, it is difficult to store and transmit stereo video due to the huge data amount. So, high efficient channel encoding algorithm and proper transmission strategy is needed to deal with the video transmission over limited bandwidth channel. In this paper, unequal error protection (UEP) based on low density parity check (LDPC) code was used to transmit stereo video over wireless channel with limited bandwidth. Different correction level LDPC code was used according to the importance of video stream to reconstruction at the receiver. Simulation result shows that the proposed transmission scheme increases the PSNR of reconstructed image, and improves the subjective effect.
文摘This paper described a signal processor for the Reed-Solomon (R-S) code using micro-programming. For the purpose of fast encoding and decoding,a formula for detecting two errors is derived, and the Qian search method for the decoding process is improved. The number of searches is significantly reduced from 256 to 4. At the same time, the circuit is simplified and the speed is increased. For the convenience of programming, a micro-programming compiling package is developed. The package can be used for programming of different formats of R-S code signal processors of DAB, MD and DCC. The software and the hardware can be used for error correcting, error detecting and error compensation of different formats of R-S code.
基金National Natural Science Foundation ofChina( No.6972 5 0 0 1)
文摘The Enhanced Variable Rate Codec (EVRC) is a standard for the Speech Service Option 3 for Wideband Spread Spectrum Digital System, which has been employed in both IS-95 cellular systems and ANSI J-STC-008 PCS (Personal Communications Systems). This paper investigated the combination of turbo codes with Unequal Error Protection (UEP) and 16-QAM modulation for EVRC codec of Rate 1 to get power and bandwidth efficient coding scheme. The results show that the UEP system outperforms the Equal Error Protection (EEP) one by 1.45 dB at BER of 10 -5.
文摘Based on the property that high degree variable nodes within an irregular LowDensity Parity-Check (LDPC) code have more powerful error-correcting capability than that of low degree variable nodes, a group of irregular LDPC codes with Unequal Error Protection (UEP)property is designed in this letter. Simulation results show that the transmission quality of the image may be effectively improved with this class of irregular LDPC code.
文摘为了提高MLC NAND Flash的抗误码性能,该文提出一种基于优化缩短极化码的MLC NAND Flash差错控制方法。优化缩短极化码通过优化删减图样得到,首先通过比特翻转重排序的方式得到基本删减图样,进而选择具有更低信道容量的冻结比特组成优化删减图样,使得到的删减比特全为冻结比特,可以显著提高删减算法的纠错性能。同时,根据MLC单元错误的不对称性,采用码率自适应的码字对FLASH中MSB和LSB进行不等错误保护。仿真结果表明:当误帧率为310-时,优化缩短极化码较相同码长的LDPC码和基本缩短极化码分别约有3.72~5.89 d B和1.47~3.49 d B增益;相比基于同一码率的优化缩短极化码方案,不等错误保护的差错控制方案获得约0.25 d B增益。
