Patent ID: 7460466

Claim:
A downlink signal constitution method, which is for a downlink of a cellular system using an orthogonal frequency division multiplexing access method, the downlink signal constitution method comprising: (a) coding, interleaving, and symbol-mapping data of a common channel and a control channel, and assigning fundamental pilot symbols, necessary for a demodulation of the common channel and the control channel, to time, frequency, and antenna; (b) receiving data to be transmitted through a traffic channel of each to user, and determining a transmission mode of each user according to the user's moving speed, channel information, and traffic requirement; (c) determining additional pilot symbols, additionally necessary for a demodulation of the traffic channel, according to the transmission mode and moving speed by users; and (d) coding, interleaving, and symbol-mapping the data of the traffic channel according to the transmission mode by users, and assigning the mapped symbols and the additional pilot symbols according to time, frequency, and antenna.