Patent ID: 7643570

Claim:
A wireless communication system for transmitting and receiving frames comprising basic pilot symbols used in propagation path estimation, control symbols conveying control information necessary for data channel demodulation, and data symbols conveying information bits, wherein a transmission device comprises: a pilot addition decision portion for deciding whether to add pilot symbols which are separate from basic pilot symbols, to frames; a control symbol generation portion for generating control symbols comprising information related to additional pilot symbols; a frame assembly portion for assembling frames to which said pilot symbols are added according to said pilot addition decision; and a transmission portion for transmitting the frames; and a reception device comprises: a control symbol demodulation portion for demodulating control symbols included in the received frames, and judges whether or not additional pilot symbols are included in the received frames based on the control symbol information; a propagation path estimation portion for estimating propagation path using the additional pilot symbols when the additional pilot symbols are included in the received frame; and a data symbol demodulation portion for demodulating data symbols based on the propagation path estimation value, wherein said transmission device comprises a propagation path information output portion, which acquires and outputs propagation path information relating to the state of the propagation path between the reception device and the transmission device, and said pilot addition decision portion decides on whether said pilot symbols are to be added, and on the number of additional pilot symbols, based on the propagation path information, and wherein said transmission device comprises a motion velocity acquisition portion which acquires the motion velocity of the reception device, and said pilot addition decision portion decides whether to arrange the additional pilot symbols in dispersed positions in a data symbol area and positions of the additional pilot symbols, according to the motion velocity of the reception device.