Transmission device, reception device, communication system, and communication method

A terminal device configured to communicate with a base station device, said terminal device comprising:

• reception circuitry configured to receive from the base station device a physical downlink shared channel, a reference signal for demodulation of the physical downlink shared channel, and a control information which includes 3-bit information, the 3-bit information indicating at least one port, one or less scrambling identity and a number of layers,
• wherein, in a case that two codewords are mapped to the physical downlink shared channel,
• among a first value to an eighth value indicated by the 3-bit information, the third value to the eighth value indicate that the number of layers is from 3 to 8 respectively, and the first value and the second value indicate that the number of layers is equal to 2, and
• the first value indicates that the scrambling identity for the reference signal is equal to 0 and the second value indicates that the scrambling identity is equal to 1.

A method used at a base station device which is configured to communicate with a terminal device, the method comprising:

• generating, by control information generation circuitry, control information including 3-bit information, the 3-bit information indicating at least one port, one or less scrambling identity and a number of layers, and
• transmitting, by transmit circuitry, a physical downlink shared channel, a reference signal for demodulation of the physical downlink shared channel, and the control information,
• wherein, in a case that two codewords are mapped to the physical downlink shared channel,
• among a first value to an eighth value indicated by the 3-bit information, the third value to the eighth value indicate that the number of layers is from 3 to 8 respectively, and the first value and the second value indicate that the number of layers is equal to 2, and
• the first value indicates that the scrambling identity for the reference signal is equal to 0 and the second value indicates that the scrambling identity is equal to 1.

A method used at a terminal device which is configured to communicate with a base station device, the method comprising:

• receiving, by reception circuitry, a physical downlink shared channel, a reference signal for demodulation of the physical downlink shared channel, and a control information including 3-bit information, the 3-bit information indicating at least one port, one or less scrambling identity and a number of layers,
• wherein, in a case that two codewords are mapped to the physical downlink shared channel,
• among a first value to an eighth value indicated by the 3-bit information, the third value to the eighth value indicate that the number of layers is from 3 to 8 respectively, and the first value and the second value indicate that the number of layers is equal to 2, and
• the first value indicates that the scrambling identity for the reference signal is equal to 0 and the second value indicates that the scrambling identity is equal to 1.