By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is b...By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is based on the cyclic redundancy check( CRC) of the messages in the subframes 2 and 3. The simulation results show that average number of iterations of the proposed strategy is less than that of the standard ET strategy,with nearly no degradation in decoding performance. Besides,the proposed ET strategy can be efficiently implemented in a sequential or parallel manner. Thus,the proposed ET strategy is attractive for practical purposes.展开更多
A novel drop unit for the optical code-division multiple access(OCDMA) based on fiber Bragg gratings and two-dimensional wavelength-time code is studied.The simple OCDMA drop unit can drop a code channel without distu...A novel drop unit for the optical code-division multiple access(OCDMA) based on fiber Bragg gratings and two-dimensional wavelength-time code is studied.The simple OCDMA drop unit can drop a code channel without disturbing the rest code channels.A similar unit for dropping a group of code channels is also proposed.Numerical simulation is given.The system delay can decrease by substituting the electrieal driving optical switch with a specific optical driving.The single channel drop unit can also be the basis for multiple channels drop.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.61271423)
文摘By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is based on the cyclic redundancy check( CRC) of the messages in the subframes 2 and 3. The simulation results show that average number of iterations of the proposed strategy is less than that of the standard ET strategy,with nearly no degradation in decoding performance. Besides,the proposed ET strategy can be efficiently implemented in a sequential or parallel manner. Thus,the proposed ET strategy is attractive for practical purposes.
基金Supported by National Hi-tech863 project(No.2002 AA 311141)
文摘A novel drop unit for the optical code-division multiple access(OCDMA) based on fiber Bragg gratings and two-dimensional wavelength-time code is studied.The simple OCDMA drop unit can drop a code channel without disturbing the rest code channels.A similar unit for dropping a group of code channels is also proposed.Numerical simulation is given.The system delay can decrease by substituting the electrieal driving optical switch with a specific optical driving.The single channel drop unit can also be the basis for multiple channels drop.
基金Supported by the National Natural Science Foundation of China (No. 81603342)the Guangdong Provincial Key Laboratory of Traditional Chinese Medicine Informatization (No. 2021B1212040007)+5 种基金the Guangdong Basic and Applied Basic Re-search Foundation (No. 2022A1515012641No. 2024A1515012948)the Guangdong Provincial Bureau of Traditional Chinese Medi-cine Research Project (No. 20221107)the Guangzhou Science and Technology Projects (No. 2024A03J0154No. 2023B01J1004)the Foshan “Summit Plan” of Building High-Level Hospitals。
