Transmission apparatus, receiving apparatus, and radio communication method

摘要

A transmission apparatus includes (N+1) or more transmission antennas. A first receiving apparatus detects N or fewer transmission antennas from a received signal. A second receiving apparatus detects more than N transmission antennas from a received signal. The transmission apparatus uses a first radio resource for outputting a known signal from each of transmission antennas and uses a second radio resource for outputting a known signal from at least one of the transmission antennas. A timing difference between the first and second radio resources is smaller than or equal to a first determined difference and a frequency difference therebetween is smaller than or equal to a second determined difference. The first receiving apparatus estimates a channel state based on the known signal outputted on the first radio resource. The second receiving apparatus estimates a channel state based on the known signals outputted on the first and second radio resources.

主权项

1. A transmission apparatus for performing radio communication with a first type of receiving apparatus which can detect not more than N transmission antennas from a received signal and a second type of receiving apparatus which can detect more than N transmission antennas from a received signal, where N is an integer greater than or equal to one, the transmission apparatus comprising:
(N+1) or more transmission antennas including a first transmission antenna and a second transmission antenna; and a control section which assigns a radio resource to a signal outputted from each of the (N+1) or more transmission antennas, wherein: the control section exercises control so as to use a first radio resource for outputting known signals α0 and α1 used by the first type of receiving apparatus and the second type of receiving apparatus from the first transmission antenna and the second transmission antenna and to use a second radio resource for outputting known signals β0 and β1 used by the second type of receiving apparatus from the first transmission antenna and the second transmission antenna, respectively; and a timing difference between the first radio resource and the second radio resource is smaller than or equal to a first determined difference and a frequency difference between the first radio resource and the second radio resource is smaller than or equal to a second determined difference, wherein the known signal α0 outputted from the first transmission antenna, the known signal α1 outputted from the second transmission antenna, the known signal β0 outputted from the first transmission antenna, and the known signal β1 outputted from the second transmission antenna satisfy β0=α1* and β1=−α0*, where * indicates a complex conjugate operation.