Adaptive channel estimation method used in multi-carrier communication system

An adaptive channel estimation method utilized in a multicarrier communication system, the multicarrier communication system transmitting a symbol through a plurality of subchannels, the plurality of subchannels comprising a plurality of pilot signal subchannels and a plurality of data signal subchannels, the pilot signal subchannels transmitting a plurality of pilot signals of the symbol, the data signal subchannels transmitting a plurality of data signals of the symbol, the method comprising:

• categorizing each of the subchannels according to a relative position of each of the subchannels with respect to at least one of the pilot signal subchannels and thereby determining a type of each of the subchannels, the categorizing step comprising a step of categorizing the subchannels according to a result of ((n+k) mod 4) and a result of (k mod 3), wherein n is the number of the symbol, k is the number of one of the subchannels, and mod represents modulus function;
• determining channel response(s) of one or more of the pilot signal subchannels with respect to their types;
• and
• estimating channel responses of the data signal subchannels according to the channel response(s) of the one or more of the pilot signal subchannels.

An adaptive channel estimation method utilized in a multicarrier communication system, the multicarrier communication system transmitting a symbol through a plurality of subchannels, the plurality of subchannels comprising a plurality of pilot signal subchannels and a plurality of data signal subchannels, the pilot signal subchannels transmitting a plurality of pilot signals of the symbol, the data signal subchannels transmitting a plurality of data signals of the symbol, the method comprising:

• categorizing each of the subchannels according to a relative position of each of the subchannels with respect to at least one of the pilot signal subchannels, the categorizing step comprising:
• if a kth subchannel is a continual pilot signal subchannel or a scattered pilot signal subchannel:
• categorizing the kth subchannel as a class_1 subchannel if both a (k+3)th subchannel and a (k−9)th subchannel transmit pilot signals;
• categorizing the kth subchannel as a class_2 subchannel if both a (k+6)th subchannel and a (k−6)th subchannel transmit pilot signals;
• and
• categorizing the kth subchannel as a class_3 subchannel if both a (k+9)th subchannel and a (k−3)th subchannel transmit pilot signals;
• and
• if the kth subchannel is a simple data signal subchannel:
• categorizing the kth subchannel as a class_4 subchannel if a (k−1)th subchannel and a (k+2)th subchannel are continual or scattered pilot signal subchannels;
• and
• categorizing the kth subchannel as a class_5 subchannel if a (k−2)th subchannel and a (k+1)th subchannel are continual or scattered pilot signal subchannels;
• determining channel response(s) of one or more of the class_1 through class_3 subchannels;
• and
• estimating channel responses of the data signal subchannels according to the channel response(s) of the one or more of the class_1 through class_3 subchannels.