Communication apparatus
A base station apparatus controls an access scheme for each radio resource by using higher layer signaling such that only signals generated by a same type of a signal generation method are multiplexed for each radio resource.
1. A communication apparatus for communicating with a terminal apparatus using a plurality of multiple access schemes, the communication apparatus comprising:
a controller configured to generate a control signal to be sent to the terminal apparatus; and
a receiver configured to receive a signal from the terminal apparatus, wherein:
the control signal is used to identify a communication slot that allows grant-free communication with the terminal apparatus,
the control signal includes at least one of an allocated time interval and a multiple access scheme in the plurality of multiple access schemes used to perform communications between the terminal apparatuses and the communication apparatus,
in a case that the multiple access scheme is Discrete Fourier Transform Spread Orthogonal Frequency-Division Multiplexing (DFT-S-OFDM), either a grant-free communication or a granted communication is selected for an uplink (UL) data transmission, and
in a case that the multiple access scheme is Cyclic-Prefix Orthogonal Frequency-Division Multiplexing (CP-OFDM), both a grant-free communication and a granted communication are performed at a same time in a range of an allowable total transmit power.
2. The communication apparatus of claim 1 , wherein:
in a case that the allocated time interval is equal to or shorter than a predetermined time interval, the grant-free communication is performed for the UL data transmission, and
in a case that the allocated time interval is longer than the predetermined time interval, the granted communication is performed for the UL data transmission.
3. The communication apparatus of claim 1 , wherein:
in a case that the multiple access scheme is CP-OFDM, a non-continuous spectrum allocation is performed, and
a spreading code including zero is used for spreading modulation symbols in at least one of a frequency domain and a time domain.
4. The communication apparatus of claim 3 , wherein a bitmap is configured by radio resource control (RRC) signaling to indicate a rule for performing the non-continuous spectrum allocation.