MIMO transmission and reception methods and devices
In a wireless transmitting device which performs transmission by an OFDM using a plurality of subcarriers orthogonal to each other, a plurality of preambles to which a plurality of different subcarrier groups selected from a plurality of subcarriers within an OFDM signal band are allocated are transmitted by using a plurality of transmit antennas, and data is transmitted by using the antennas after the preambles are transmitted.
1. A wireless transmitting method of performing transmission by orthogonal frequency division multiplexing (OFDM) using a plurality of subcarriers orthogonal to each other, the method comprising:
transmitting, by using a plurality of transmit antennas, a plurality of preambles formed of a plurality of different subcarrier groups selected from the plurality of subcarriers; and
transmitting data by using the plurality of transmit antennas after the plurality of preambles are transmitted, wherein
transmitting the plurality of preambles includes, if a fading status of a propagation path to a wireless receiving device is short-delay fading, sequentially allocating, to each of the plurality of subcarrier groups of the plurality of preambles, subcarriers selected one by one from the plurality of subcarriers in order of arrangement, and, if a fading status of a propagation path is long-delay fading, allocating, to each of the plurality of subcarrier groups of the plurality of preambles, subcarriers selected from the plurality of subcarriers for each of a plurality of partial bands obtained by dividing a signal band in which the OFDM system is used.
2. The method according to claim 1 , wherein a preamble of the plurality of preambles contains a short preamble, a long preamble, and at least one signal field.
3. The method according to claim 2 , wherein the at least one signal field contains a first signal field based on IEEE 802.11 a.
4. The method according to claim 2 , wherein the at least one signal field contains a first signal field based on IEEE 802.11 a, and a second signal field placed after the first signal field and based on a standard other than IEEE 802.11 a.