Patent ID: 8351463

Claim:
A radio apparatus for transmitting packet signals composed of a plurality of streams, the apparatus comprising: an input unit which inputs a plurality of combinations of a control signal on a data signal and said data signal wherein the combinations contain data signals which are to be assigned respectively to a plurality of streams; a generation unit which generates packet signals in a manner such that while a Legacy-Long Training Field (L-LTF) is being assigned anterior to a control signal contained in a leading combination among the plurality of combinations inputted by said input unit and High Throughput-Long Training Field (HT-LTF) is being assigned posterior to said control signal, a data signal contained in the leading combination is assigned posterior to the HT-LTF, an HT-LTF is appended to at least one of the remaining combinations and the remaining combinations are sequentially assigned, posterior to said data signal; and a transmitter which transmits the packet signals generated by said generation unit, wherein while using as a reference an L-LTF assigned to one of the plurality plurality of streams and applying a cyclic timing shift within L-LTFs respectively assigned to the plurality of streams, said generation unit applies also a timing shift to HT-LTFs respectively assigned to the plurality of streams and control signals respectively assigned to the plurality of streams, wherein while setting an amount of timing shift to different values for the L-LTFs and the HT-LTFs, said generation unit sets an amount of timing shift for a control signal contained in the leading combination to be equal to an amount of timing shift for an L-LTF contained in the leading combination, and amounts of timing shift for control signals contained in the remaining combinations are equal to amounts of timing shift for HT-LTFs contained in the remaining combinations.