| Abstract: | A carrier recovery method of the power spectrum center difference adapting to the mobile channel of the MC CDMA system with serious Doppler shift using double pilots is presented. In the transmitter, two pilots of equal frequency distance to the carrier with one putting on the left position and the other on the right position of the carrier frequency are used. Even if a continuous sine wave is transmitted, the power spectrum is expanded to a Doppler band in the receiver owing to the multi path transmission and the Doppler shift. The pilot spectrum is made to pass through two narrow band filters which are transformed to the base band with local carrier wave in the receiver. The frequency difference between the local carrier and the transmitter carrier is obtained when the difference of the gravity centers of the two pilot spectra is computed. |
