In this paper, a novel multiple trellis coded orthogonal transmit scheme is proposed to exploit transmit diversity in fading channels. In this scheme, a unique vector from a set of orthogonal vectors is assigned to ea...In this paper, a novel multiple trellis coded orthogonal transmit scheme is proposed to exploit transmit diversity in fading channels. In this scheme, a unique vector from a set of orthogonal vectors is assigned to each transmit antenna. Each of the output symbols from the multiple trellis encoder is multiplied with one of these orthogonal vectors and transmitted from corresponding transmit antennas. By correlating with corresponding orthogonal vectors, the receiver separates symbols transmitted from different transmit antennas. This scheme can be adopted in coherent/differential systems with any number of transmit antennas. It is shown that the proposed scheme encompasses the conventional trellis coded unitary space-time modulation based on the optimal cyclic group codes as a special case. We also propose two better designs over the conventional trellis coded unitary space-time modulation. The first design uses 8 Phase Shift Keying （8-PSK） constellations instead of 16 Phase Shift Keying （16-PSK） constellations in the conventional trellis coded unitary space-time modulation. As a result, the product distance of this new design is much larger than that of the conventional trellis coded unitary space-time modulation. The second design introduces constellations with multiple levels of amplitudes into the design of the multiple trellis coded orthogonal transmit scheme. For both designs, simulations show that multiple trellis coded orthogonal transmit schemes can achieve better performance than the conventional trellis coded unitarv space-time schemes.展开更多
OBJECTIVE: To describe the key systems used for Traditional Chinese Medicine(TCM) classification.METHODS: The TCM classifications used in the International Classification of Diseases-9 Clinical Modification(ICD-9-CM) ...OBJECTIVE: To describe the key systems used for Traditional Chinese Medicine(TCM) classification.METHODS: The TCM classifications used in the International Classification of Diseases-9 Clinical Modification(ICD-9-CM) volume 3, the ICD-10 Procedure Coding System, the International Classification of Health Interventions, and the Medical Subject Headings(Me SH) and Chinese Traditional Medicine and Materia Medica Subject Headings(TCMe SH) thesauruses were compared regarding descriptive terms, structure, and features of TCM interventions.RESULTS: The National Library of Medicine's Me SH thesaurus is ubiquitous. The ICD-9-CM(volume 3),ICD-10 Procedure Coding System, and International Classification of Health Interventions cover insufficient concepts of TCM, and cannot be used directly as classification systems for TCM interventions. In contrast, the TCM contents of the TCMe SH thesaurus are complete, systematic, and detailed, and its hierarchical structure can be used for effective TCM classification.CONCLUSION: TCM classification is very limited and flawed. The Me SH thesaurus helps decrease the detrimental effect of the language barrier. Similarly, the TCMe SH thesaurus can help those without full command of the Mandarin language to access Chinese literature, but the value of searches using TCMe SH could be improved by collaborative working with Information Specialists who are fluent in Mandarin and understand TCM.展开更多
基金Supported by the National Natural Science Foundation of China(No.60390540).
文摘In this paper, a novel multiple trellis coded orthogonal transmit scheme is proposed to exploit transmit diversity in fading channels. In this scheme, a unique vector from a set of orthogonal vectors is assigned to each transmit antenna. Each of the output symbols from the multiple trellis encoder is multiplied with one of these orthogonal vectors and transmitted from corresponding transmit antennas. By correlating with corresponding orthogonal vectors, the receiver separates symbols transmitted from different transmit antennas. This scheme can be adopted in coherent/differential systems with any number of transmit antennas. It is shown that the proposed scheme encompasses the conventional trellis coded unitary space-time modulation based on the optimal cyclic group codes as a special case. We also propose two better designs over the conventional trellis coded unitary space-time modulation. The first design uses 8 Phase Shift Keying （8-PSK） constellations instead of 16 Phase Shift Keying （16-PSK） constellations in the conventional trellis coded unitary space-time modulation. As a result, the product distance of this new design is much larger than that of the conventional trellis coded unitary space-time modulation. The second design introduces constellations with multiple levels of amplitudes into the design of the multiple trellis coded orthogonal transmit scheme. For both designs, simulations show that multiple trellis coded orthogonal transmit schemes can achieve better performance than the conventional trellis coded unitarv space-time schemes.
文摘OBJECTIVE: To describe the key systems used for Traditional Chinese Medicine(TCM) classification.METHODS: The TCM classifications used in the International Classification of Diseases-9 Clinical Modification(ICD-9-CM) volume 3, the ICD-10 Procedure Coding System, the International Classification of Health Interventions, and the Medical Subject Headings(Me SH) and Chinese Traditional Medicine and Materia Medica Subject Headings(TCMe SH) thesauruses were compared regarding descriptive terms, structure, and features of TCM interventions.RESULTS: The National Library of Medicine's Me SH thesaurus is ubiquitous. The ICD-9-CM(volume 3),ICD-10 Procedure Coding System, and International Classification of Health Interventions cover insufficient concepts of TCM, and cannot be used directly as classification systems for TCM interventions. In contrast, the TCM contents of the TCMe SH thesaurus are complete, systematic, and detailed, and its hierarchical structure can be used for effective TCM classification.CONCLUSION: TCM classification is very limited and flawed. The Me SH thesaurus helps decrease the detrimental effect of the language barrier. Similarly, the TCMe SH thesaurus can help those without full command of the Mandarin language to access Chinese literature, but the value of searches using TCMe SH could be improved by collaborative working with Information Specialists who are fluent in Mandarin and understand TCM.
