| 摘要 |
Multiple carriers are generated, modulated by data to be transmitted, as sho wn by oscillators (2-5) and modulators (21, 22, 31, 32, etc.) (or using Fourier transform techniques). They follow two paths. One path via adder (81) takes a set of carriers at integer multiples of a windowing frequency (f), where the odd carriers have some reference phase and the even carriers are in phase quadrature. The other path via adder (82) takes a second set of carriers, again at integer multiples of the windowing frequency; here the even carrier s have the reference phase and the odd carriers are in phase quadrature. In th e first path the signal is multiplied at (91) by a windowing function with a period equal to the reciprocal of the windowing frequency, whilst in the second path the signal is multiplied at (92) by a similar function which is time-shifted (by a delay 211) by half of the said period.
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