Terminal and radio communication method
A terminal according to one aspect of the present disclosure includes: a control section that assumes that a frequency domain orthogonal cover code (FD-OCC) having a sequence length of a number larger than two is applied to a demodulation reference signal mapped to a pair of resource elements the number of which is greater than two and that are being different in frequency; and a transmitting/receiving section that performs transmission processing or reception processing of the demodulation reference signal, based on the FD-OCC. According to one aspect of the present disclosure, even when there are terminals according to different releases, each of the terminals can appropriately perform communication.
1. A terminal comprising:
a processor that,
if receiving configuration information of a demodulation reference signal (DMRS) having a greater number of configurable ports than a given number, applies a frequency domain orthogonal cover code (FD-OCC) having a sequence length of a number greater than two to a first DMRS, the first DMRS being mapped to first resource elements having mutually different frequencies, a number of the first resource elements being the number greater than two, and
if not receiving the configuration information, applies an FD-OCC having a sequence length of two to a second DMRS, the second DMRS being mapped to second resource elements having mutually different frequencies, a number of the second resource elements being the number greater than two; and
a transmitter that transmits the first DMRS or the second DMRS.
2. The terminal according to claim 1 , wherein if receiving the configuration information, the processor applies the FD-OCC having the sequence length of the number greater than two to the first DMRS that is mapped to the first resource elements across a plurality of physical resource blocks.
3. The terminal according to claim 1 , wherein if receiving the configuration information, the processor maps the first DMRS to a subcarrier k,
wherein when the first DMRS corresponds to DMRS configuration type 1, k=8n+2k′+Δ (n=0, 1, . . . ; k′=0, 1, 2, 3), and
when the first DMRS corresponds to DMRS configuration type 2, k=12n+k′+Δ (n=0, 1, . . . ; k′=0, 1) or k=12n+k′+Δ+4 (n=0, 1, . . . ; k′=2, 3).
4. The terminal according to claim 1 , wherein a sequence of the FD-OCC having the sequence length of the number greater than two is any one of {+1, +1, +1, +1}, {+1, −1, +1, −1}, {+1, +j, −1, −j}, and {+1, −j, −1, +j}.
5. The terminal according to claim 2 , wherein if receiving the configuration information, the processor maps the first DMRS to a subcarrier k,
wherein when the first DMRS corresponds to DMRS configuration type 1, k=8n+2k′+Δ (n=0, 1, . . . ; k′=0, 1, 2, 3), and
when the first DMRS corresponds to DMRS configuration type 2, k=12n+k′+Δ (n=0, 1, . . . ; k′=0, 1) or k=12n+k′+Δ+4 (n=0, 1, . . . ; k′=2, 3).
6. The terminal according to claim 2 , wherein a sequence of the FD-OCC having the sequence length of the number greater than two is any one of {+1, +1, +1, +1}, {+1, −1, +1, −1}, {+1, +j, −1, −j}, and {+1, −j, −1, −Fj}.
7. The terminal according to claim 3 , wherein a sequence of the FD-OCC having the sequence length of the number greater than two is any one of {+1, +1, +1, +1}, {+1, −1, +1, −1}, {+1, +j, −1, −j}, and {+1, −j, −1, −Fj}.
8. A radio communication method for a terminal, comprising:
in response to configuration information of a demodulation reference signal (DMRS) having a greater number of configurable ports than a given number being received, applying a frequency domain orthogonal cover code (FD-OCC) having a sequence length of a number greater than two to a first DMRS, the first DMRS being mapped to first resource elements having mutually different frequencies, a number of the first resource elements being the number greater than two, and
in response to the configuration information being not received, applying an FD-OCC having a sequence length of two to a second DMRS, the second DMRS being mapped to second resource elements having mutually different frequencies, a number of the second resource elements being the number greater than two; and
transmitting the first DMRS or the second DMRS.
9. A base station comprising:
a receiver that,
if configuration information of a demodulation reference signal (DMRS) having a greater number of configurable ports than a given number is transmitted to a terminal, receives a first DMRS that is:
mapped to first resource elements having mutually different frequencies, a number of the first resource elements being a number greater than two, and
transmitted upon a frequency domain orthogonal cover code (FD-OCC) having a sequence length of the number greater than two being applied to the first DMRS, and
if the configuration information is not transmitted to the terminal, receives a second DMRS that is:
mapped to second resource elements having mutually different frequencies, a number of the second resource elements being the number greater than two, and
transmitted upon an FD-OCC having a sequence length of two being applied to the second DMRS; and
a processor that controls a reception process of the first DMRS or the second DMRS.
10. A system comprising a terminal and a base station, wherein
the terminal comprises:
a processor that,
if receiving configuration information of a demodulation reference signal (DMRS) having a greater number of configurable ports than a given number, applies a frequency domain orthogonal cover code (FD-OCC) having a sequence length of a number greater than two to a first DMRS, the first DMRS being mapped to first resource elements having mutually different frequencies, a number of the first resource elements being the number greater than two, and
if not receiving the configuration information, applies an FD-OCC having a sequence length of two to a second DMRS, the second DMRS being mapped to second resource elements having mutually different frequencies, a number of the second resource elements being the number greater than two; and
a transmitter that transmits the first DMRS or the second DMRS, and
the base station comprises:
a receiver that receives the first DMRS or the second DMRS.