Multiplex communications – Generalized orthogonal or special mathematical techniques – Quadrature carriers
Patent
1994-07-27
1997-10-07
Hsu, Alpus H.
Multiplex communications
Generalized orthogonal or special mathematical techniques
Quadrature carriers
370210, 370343, 370480, 375260, 375340, H04T 1100
Patent
active
056755724
ABSTRACT:
An orthogonal frequency division multiplex (OFDM) modulation apparatus which can transmit just one of single side bands by a simple circuit and an OFDM demodulation apparatus superior in the ratio of the signal power to noise power ratio, wherein a serial/parallel converter converts the input signal from the serial to parallel format, inputs the results to the 1 to N-1 stage of an inverse discrete Fourier transformation (IDFT) circuit, and inputs a fixed value to the other stages (0 stage and N stage to 2N-1 stage). The IDFT circuit is a 2N input IDFT circuit which performs IDFT processing on the input signal converted to the parallel format by the serial/parallel converter and inputs the real number portion of the transformation result to a parallel/serial converter and the imaginary number portion to a parallel/serial converter. The imaginary number portion of the output signal of the IDFT circuit becomes the Hilbert transformation of the real number portion. These output signals are combined by modulation by two orthogonal carrier wave signals of the same frequency so as to take out just a single side band signal of the demodulated signal.
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"Multicarrier Transmission Technique in Cellular Mobile Communications Systems" Reiners et al.; Vehicular Technology, 1994 Conference, pp. 1645-1649.
Hidejima, deceased Yasuhiro
Hidejima, legal representative Takako
Ikeda Yasunari
Frommer William S.
Hsu Alpus H.
Rao Seema S.
Sinderbrand Alvin
Sony Corporation
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