Patent ID: 8149930

Claim:
A radio apparatus for transmitting, in a predetermined period of time, to at least one terminal apparatus each of a plurality of data signals arranged in a time direction by at least one stream, the apparatus comprising: an input unit which inputs the plurality of data signals; a specifying unit which specifies a terminal apparatus to which long training fields (LTFs) respectively assigned to streams of a number greater than that of streams for transmitting the plurality of data signals, are to be transmitted, among terminal apparatuses to which the plurality of data signals inputted in said input unit are to be transmitted; a generation unit which generates packet signals in a manner that: short training fields (STFs), long training fields(LTFs), and control signal are appended to main streams where data signals which are to be transmitted to the terminal apparatus specified by said specifying unit are assigned, and only LTFs are assigned to sub-streams to which no control signals or data signals are assigned, and while the data signals that should be transmitted to the terminal apparatus specified by the specifying unit are assigned to a rear part in the plurality of data signals, and STFs and LTFs respectively assigned to streams corresponding to respective streams of the plurality of data signals in a leading part are appended to a leading part in the plurality of data signals; and a transmitter which transmits a packet signal generated by said generation unit.