Base station apparatus, terminal apparatus, and communication method for these apparatuses

A communication method used for a base station apparatus for communicating with a terminal apparatus, the communication method comprising:

• a reception step of receiving a physical uplink shared channel, and a reference signal used to demodulate the physical uplink shared channel;
• and
• a transmission step of transmitting a signal indicating a delivery confirmation for the physical uplink shared channel, wherein
• the physical uplink shared channel includes uplink data bits, identifier bits indicating a terminal apparatus that has transmitted the uplink data bits, first Cyclic Redundancy Check (CRC) bits generated from the identifier bits, and second CRC bits generated from the uplink data bits,
• in the reception step, the first CRC bits are descrambled by using a sequence of the reference signal, and the second CRC bits are descrambled by using an identifier indicating the terminal apparatus,
• in the transmission step, in a case that an error is detected based on the first CRC bits, a first Negative Acknowledgement (NACK) is transmitted by using a control signal associated with the sequence of the reference signal, and
• in a case that an error is detected based on the second CRC bits, a second NACK is transmitted by using a control signal associated with the identifier indicating the terminal apparatus.

A terminal apparatus for communicating with a base station apparatus, terminal apparatus comprising:

• a transmitter configured to transmit a physical uplink shared channel, and a reference signal used to demodulate the physical uplink shared channel;
• and
• a receiver configured to receive a signal indicating a delivery confirmation for the physical uplink shared channel, wherein
• the physical uplink shared channel includes uplink data bits, identifier bits indicating a terminal apparatus that has transmitted the uplink data bits, first Cyclic Redundancy Check (CRC) bits generated from the identifier bits, and second CRC bits generated from the uplink data bits,
• the transmitter scrambles the first CRC bits by using a sequence of the reference signal, and scrambles the second CRC bits by using an identifier indicating the terminal apparatus,
• in a case that the receiver receives a Negative Acknowledgement (NACK) on a control signal associated with the sequence of the reference signal, the receiver interprets that identification of the terminal apparatus has failed,
• in a case that the receiver receives a NACK on a control signal associated with the identifier indicating the terminal apparatus, the receiver interprets that decoding of the uplink data bits has failed, and
• in a case that the receiver receives neither of the control signals within a prescribed period of time, the receiver interprets that the reference signal has not been recognized.

A communication method used for a terminal apparatus for communicating with a base station apparatus, the communication method comprising:

• a transmission step of transmitting a physical uplink shared channel, and a reference signal used to demodulate the physical uplink shared channel;
• and
• a reception step of receiving a signal indicating a delivery confirmation for the physical uplink shared channel, wherein
• the physical uplink shared channel includes uplink data bits, identifier bits indicating a terminal apparatus that has transmitted the uplink data bits, first Cyclic Redundancy Check (CRC) bits generated from the identifier bits, and second CRC bits generated from the uplink data bits,
• in the transmission step, the first CRC bits are scrambled by using a sequence of the reference signal, and the second CRC bits are scrambled by using an identifier indicating the terminal apparatus,
• in the reception step, in a case that a Negative Acknowledgement (NACK) is received on a control signal associated with the sequence of the reference signal, it is interpreted that identification of the terminal apparatus has failed,
• in a case that a NACK(is received on a control signal associated with the identifier indicating the terminal apparatus, it is interpreted that decoding of the uplink data bits has failed, and
• in a case that neither of the control signals is received within a prescribed period of time, it is interpreted that the reference signal has not been recognized.