Base station device, radio communication device, and radio communication system
A base station device that includes a controller that notifies a terminal device of first information regarding a signal waveform to be used in downlink communication in an initial connection procedure performed with the terminal device among a first signal waveform and a second signal waveform and performs the downlink communication with the signal waveform to be used based on the first information.
1 . A base station device comprising:
a controller configured to:
notify a terminal device of first information regarding a signal waveform to be used in downlink communication in an initial connection procedure performed with the terminal device among a first signal waveform and a second signal waveform; and
perform the downlink communication in the initial connection procedure with the signal waveform to be used based on the first information,
wherein the first signal waveform includes a multi-carrier signal, and the second signal waveform includes a single-carrier signal.
2 . The base station device according to claim 1 , further comprising:
a first signal waveform transmitter that generates the first signal waveform and transmits the first signal waveform; and
a second signal waveform transmitter that generates the second signal waveform and transmits the second signal waveform, wherein
the second signal waveform transmitter generates the second signal waveform using transform precoding, and
the first signal waveform transmitter generates the first signal waveform without using the transform precoding.
3 . The base station device according to claim 2 , wherein
the second signal waveform transmitter combines signals addressed to a plurality of the terminal devices and performs the transform precoding on the combined signals.
4 . The base station device according to claim 2 , wherein
the second signal waveform transmitter combines signals addressed to one or a plurality of the terminal devices and a broadcast signal, and performs the transform precoding on the combined signals.
5 . The base station device according to claim 2 , wherein
the second signal waveform transmitter performs the transform precoding on signals addressed to a plurality of the terminal devices for each terminal device, and maps the transform-precoded signals of the plurality of terminal devices onto contiguous resources in a frequency domain.
6 . The base station device according to claim 5 , wherein
the second signal waveform transmitter maps the transform-precoded signals of at least one terminal device among the plurality of terminal devices onto non-contiguous resources in the frequency domain.
7 . The base station device according to claim 1 , wherein
the first information includes information regarding the number of transmission layers used in the downlink communication.
8 . The base station device according to claim 1 , wherein
the controller performs downlink communication with the terminal device using one of the first signal waveform and the second signal waveform, and
when switching the one signal waveform to the other of the first signal waveform and the second signal waveform, the controller notifies the terminal device of second information regarding switching of the signal waveform.
9 . The base station device according to claim 1 , wherein
when switching the signal waveform to be used from one of the first signal waveform and the second signal waveform to the other, the controller notifies the terminal device of third information regarding a start timing of using the other signal waveform, and
based on the third information, the controller switches the signal waveform to be used to the other signal waveform at the start timing.
10 . The base station device according to claim 1 , wherein
when switching the signal waveform to be used from one of the first signal waveform and the second signal waveform to the other, the controller notifies the terminal device of fourth information regarding a period in which the other signal waveform is used, and
based on the fourth information, the controller perform downlink communication with the terminal device based on the other signal waveform during at least a part of the period.
11 . The base station device according to claim 10 , wherein
after the period has elapsed, the controller switches the signal waveform used for downlink communication with the terminal device from the other signal waveform to the one signal waveform.
12 . The base station device according to claim 1 , wherein
the controller determines one of the first signal waveform and the second signal waveform as a signal waveform to be used for downlink communication with the terminal device according to at least one of altitude and performance of the base station device, and performs the downlink communication with the terminal device using the one signal waveform.
13 . A terminal device comprising:
a controller configured to:
acquire first information regarding a signal waveform to be used in downlink communication in an initial connection procedure performed with a base station device among a first signal waveform and a second signal waveform; and
perform the downlink communication in the initial connection procedure based on the first information,
wherein the first signal waveform includes a multi-carrier signal, and the second signal waveform includes a single-carrier signal.
14 . The terminal device according to claim 13 , wherein
the first signal waveform is a signal generated using transform precoding, and
the second signal waveform is a signal generated without using the transform precoding.
15 . The terminal device according to claim 13 , further comprising:
a first signal waveform receiver that performs reception processing of the first signal waveform;
a second signal waveform receiver that performs reception processing of the second signal waveform; and
a signal waveform switch configured to:
when performing first processing with the base station device, provide a signal received on downlink from the base station device to one of the first signal waveform receiver and the second signal waveform receiver; and
when performing second processing different from the first processing with the base station device, provide
the signal received on downlink from the base station device to the other of the first signal waveform receiver and the second signal waveform receiver.
16 . The terminal device according to claim 15 , wherein
the first processing includes at least one of:
synchronization signal transmission/reception processing;
transmission/reception processing of at least one of message 2, message 4 and message B in a random access procedure;
control signal transmission/reception processing; and
reference signal transmission/reception processing.
17 . The terminal device according to claim 15 , further comprising:
a first signal waveform receiver that performs reception processing of the first signal waveform;
a second signal waveform receiver that performs reception processing of the second signal waveform; and
a signal waveform switch that provides a signal received on downlink from the base station device to one of the first signal waveform receiver and the second signal waveform receiver, wherein
the controller acquires information regarding transmission timing of uplink communication to the base station device, and
the signal waveform switch determines a signal waveform receiver that provides the received signal from among the first signal waveform receiver and the second signal waveform receiver based on the information regarding the transmission timing.
18 . A radio communication system comprising a base station device and a terminal device, wherein
the base station device includes a first controller configured to notify the terminal device of first information regarding a signal waveform to be used in downlink communication in an initial connection procedure performed with the terminal device among a first signal waveform and a second signal waveform and perform the downlink communication in the initial connection procedure with the signal waveform to be used based on the first information, and
the terminal device includes a second controller configured to acquire the first information from the base station device and perform the downlink communication in the initial connection procedure based on the first information,
wherein the first signal waveform includes a multi-carrier signal, and the second signal waveform includes a single-carrier signal.