Path search method, channel estimation method and communication device

A channel estimation method for estimating channel variation using pilot symbols by detecting timings of path components included in a signal received via a multipath propagation path, said method comprising:

• a first path search step detecting the timings of the path components using pilot symbols of a known phase in said signal received via the multipath propagation path;
• a first channel estimation step estimating the channel variation using the pilot symbols of the known phase, after said first path search step;
• a second path search step detecting the timings of the path components using the timings detected in said first path search step, information symbols that are derived from a signal demodulated according to said first channel estimation step, and the pilot symbols of the known phase;
• and
• a second channel estimation step estimating the channel variation using the information symbols that are derived from the signal demodulated according to said first channel estimation step, and the pilot symbols of the known phase, according to the timings detected in said second path search step.

A communication device comprising:

• a path search and channel estimation part configured to carry out a path search and a channel estimation using pilot symbols of a known phase included in a signal received via a multipath propagation path and information symbols;
• and
• a feedback part configured to feed back said information symbols,
• wherein said path search and channel estimation part recursively implements the path search and the channel estimation by repeating processes of implementing a path search using information symbols that are decoded after a channel estimation and the pilot symbols and implementing a channel estimation using the information symbols that are fed back via said feedback part in accordance with a timing detected in said path search and the pilot symbols.