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METHOD FOR PARALLEL MULTI-FREQUENCY TRANSMISSION OF DIGITAL INFORMATION USING COMBINED MULTI-POSITION FREQUENCY AND PHASE MODULATION IN FREQUENCY SUBCHANNELS
METHOD FOR PARALLEL MULTI-FREQUENCY TRANSMISSION OF DIGITAL INFORMATION USING COMBINED MULTI-POSITION FREQUENCY AND PHASE MODULATION IN FREQUENCY SUBCHANNELS
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机译:频率子信道中多位置频率与相位调制相结合的数字信息并行多频率传输方法
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摘要
FIELD: radio engineering, communication.;SUBSTANCE: invention relates to digital communication engineering and can be used for the multi-frequency transmission of digital information via communication links. The transmission method includes the combination of digital multi-frequency and multi-position phase modulation of OFDM subcarriers, the number of which is equal to N, divided for modulation into clusters (groups) of L subcarriers. In each cluster, multi-frequency modulation symbols are transmitted by selecting R from L subcarriers, of which P are then phase-modulated, while R-P subcarriers remain unmodulated. At the receiving side, after the selection of quadrature subcarrier components in the OFDM circuit, demodulation is performed in two steps: first, multi-frequency modulation symbols are incoherently demodulated by determining R subcarriers; at the second step, using reference oscillations generated from the quadrature components of the modulated R-P subcarriers, P phase-modulated subcarriers are coherently demodulated.;EFFECT: high spectral efficiency and noise-immunity of the methods for the multi-frequency transmission of digital information, which do not require the inclusion, in the transmitted signal, of special training signals or pilot tones for channel state estimation.;6 dwg
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