Transmitting method, transmitting device, receiving method, and receiving device

Abstract

Provided is a transmitting device which can expand a communication range when performing multicast/broadcast communication. The transmitting device includes a plurality of transmission antennas, and includes: a signal processor which generates a first baseband signal by modulating data of a first stream, and a second baseband signal by modulating data of a second stream; and a transmitter which generates, from the first baseband signal, first transmission signals having different directivities, generates, from the second baseband signal, second transmission signals having different directivities, and transmits the first transmission signals and the second transmission signals at a same time. When the transmitter has received, from a terminal, a request to transmit the first stream, the transmitter further generates, from the first baseband signal, third transmission signals which are different from the first transmission signals and have different directivities, and transmits the third transmission signals.

What is claimed is: 
     
         1 . A transmitting device which includes a plurality of transmission antennas, the transmitting device comprising:
 a signal processor which generates a first baseband signal by modulating data of a first stream, and a second baseband signal by modulating data of a second stream; and   a transmitter which generates, from the first baseband signal, a plurality of first transmission signals having different directivities, generates, from the second baseband signal, a plurality of second transmission signals having different directivities, and transmits the plurality of first transmission signals and the plurality of second transmission signals at a same time, wherein   when the transmitter has received, from a terminal, a request to transmit the first stream, the transmitter further generates, from the first baseband signal, a plurality of third transmission signals which are different from the plurality of first transmission signals and have different directivities, and transmits the plurality of third transmission signals.   
     
     
         2 . The transmitting device according to  claim 1 , wherein
 each transmission signal of the plurality of first transmission signals and the plurality of second transmission signals includes a control signal for notifying which one of the data of the first stream and the data of the second stream the transmission signal is for transmitting.   
     
     
         3 . The transmitting device according to  claim 1 , wherein
 each of the plurality of first transmission signals and the plurality of second transmission signals includes a training signal for a receiving device to perform directivity control.   
     
     
         4 . A receiving device which includes a plurality of receiving antennas, the receiving device comprising:
 a receiver which selects at least one first signal and at least one second signal from among a plurality of first signals for transmitting data of a first stream and a plurality of second signals for transmitting data of a second stream, and performs directivity control for receiving the at least one first signal selected and the at least one second signal selected, to receive the at least one first signal and the at least one second signal, the plurality of first signals and the plurality of second signals having different directivities and being transmitted by a transmitting device at a same time;   a signal processor which demodulates the at least one first signal received and the at least one second signal received, and outputs the data of the first stream and the data of the second stream; and   a transmitter which requests the transmitting device to transmit the first stream when the receiver has not received the at least one first signal.   
     
     
         5 . The receiving device according to  claim 4 , wherein
 the receiver selects the at least one first signal and the at least one second signal, based on a control signal included in each of a plurality of signals to be received, the control signal being for notifying which one of the data of the first stream and the data of the second stream the signal is for transmitting.   
     
     
         6 . The receiving device according to  claim 4 , wherein
 the receiver performs the directivity control using a training signal included in each of a plurality of signals to be received.   
     
     
         7 . A transmitting method performed by a transmitting device which includes a plurality of transmission antennas, the transmitting method comprising:
 signal generating processing of generating a first baseband signal by modulating data of a first stream, and a second baseband signal by modulating data of a second stream; and   transmission processing of generating, from the first baseband signal, a plurality of first transmission signals having different directivities, generating, from the second baseband signal, a plurality of second transmission signals having different directivities, and transmitting the plurality of first transmission signals and the plurality of second transmission signals at a same time, wherein   in the transmission processing, when a request to transmit the first stream is received from a terminal, a plurality of third transmission signals which are different from the plurality of first transmission signals and have different directivities are further generated from the first baseband signal and transmitted.   
     
     
         8 . A receiving method performed by a receiving device which includes a plurality of receiving antennas, the receiving method comprising:
 receiving processing of selecting at least one first signal and at least one second signal from among a plurality of first signals for transmitting data of a first stream and a plurality of second signals for transmitting data of a second stream, and performing directivity control for receiving the at least one first signal selected and the at least one second signal selected, to receive the at least one first signal and the at least one second signal, the plurality of first signals and the plurality of second signals having different directivities and being transmitted by a transmitting device at a same time;   signal processing of demodulating the at least one first signal received and the at least one second signal received, and outputting the data of the first stream and the data of the second stream; and   transmission processing of requesting the transmitting device to transmit the first stream when the at least one first signal is not received in the receiving processing.