| 摘要 |
<p>PURPOSE:To realize the practical use for the digital process type transmitter of the orthogonal multiple signal by decreasing the necessary digital operation quantity and also omitting the T(clock cycle)/2sec. switching control circuit. CONSTITUTION:The real sample value series with every T sec. and supplied to input ends 12O-122L-1 is converted into the complex sample value series with every T/2sec. and via pre-process circuit 13. The N/4-point dats thus obtained is supplied to 1st offset Fourier reverse converter 17. At the same time, the 1st-half N/4-point data is supplied directly to 2nd offset Fourier reverse converter 17. While for the 2nd-half N/4-point data, those which received the code inversion through inverters 15O-15N/4-1 are supplied to converter 17. The 1st and 2nd polyphase circuits 20 and 21 are formed with N/2-units of complex band band filters to receive the output of converters 16 and 17 each. The output of circuits 20 and 21 receive the frequency offset at post-process circuit 25 to each of the complex signals, and thus only the real number part of the signal is delivered. And these output receive the time-division multiplication to be obtained at output end 28.</p> |
