Method and apparatus for modulation and coding scheme table switch
Embodiments of the present disclosure provide method and apparatus for MCS table switch. A method performed by a network device comprises determining that a terminal device supports a first modulation and coding scheme (MCS) and a second MCS. The method further comprises transmitting configuration information regarding a first bandwidth part associated with a first MCS table supporting the first MCS to the terminal device. The method further comprises transmitting configuration information regarding a second bandwidth part associated with a second MCS table supporting the second MCS to the terminal device. The first MCS table is different from the second MCS table.
1 . A method performed by a network device, the method comprising:
determining that a terminal device supports a first modulation and coding scheme (MCS) and a second MCS;
transmitting to the terminal device configuration information regarding a first bandwidth part associated with a first MCS table supporting the first MCS;
transmitting to the terminal device configuration information regarding a second bandwidth part associated with a second MCS table supporting the second MCS, the first MCS table being different from the second MCS table;
determining a power reduction value of the terminal device;
when the power reduction value of the terminal device is greater than the maximum power reduction value related to the first MCS and smaller than the maximum power reduction value related to the second MCS, determining the terminal device as a MCS table switch candidate; and
when the power reduction value of the terminal device is not greater than the maximum power reduction value related to the first MCS, determining the terminal device as a non MCS table switch candidate.
2 . The method of claim 1 , wherein determining the power reduction value of the terminal device comprises:
obtaining a power class of the terminal device;
obtaining a maximum transmitter power value configured to the terminal device;
obtaining a maximum transmitter power value of the terminal device; and
determining the power reduction value of the terminal device based on the power class of the terminal device, the maximum transmitter power value configured to the terminal device and the maximum transmitter power value of the terminal device.
3 . The method of claim 1 , further comprising:
determining channel quality between the network device and the terminal device; and
transmitting a command to the terminal device to switch to the first bandwidth part or the second bandwidth part based on the channel quality between the network device and the terminal device.
4 . The method of claim 3 , wherein transmitting a command to the terminal device to switch to the first bandwidth part or the second bandwidth part based on the channel quality between the network device and the terminal device comprises:
determining that the terminal device is using the second MCS table; and
when the channel quality between the network device and the terminal device falls into at least one first channel quality range that network performance using the first MCS table is higher than network performance using the second MCS table, transmitting the command to the terminal device to switch to the first bandwidth part.
5 . The method of claim 4 , wherein the at least one first channel quality range comprises:
a channel quality corresponding to the second MCS with a lowest spectral efficiency in the second MCS table, a channel quality corresponding to the second MCS with a second lowest spectral efficiency in the second MCS table, and/or
a channel quality corresponding to the first MCS with a highest spectral efficiency in the second MCS table, a channel quality corresponding to the second MCS with a third lowest spectral efficiency in the second MCS table.
6 . The method of claim 3 , wherein transmitting a command to the terminal device to switch to the first bandwidth part or the second bandwidth part based on the channel quality between the network device and the terminal device comprises:
determining that the terminal device is using the first MCS table; and
when the channel quality between the network device and the terminal device falls into at least one second channel quality range that network performance using the second MCS table is higher than network performance using the first MCS table, transmitting a command to the terminal device to switch to the second bandwidth part.
7 . The method of claim 6 , wherein the at least one second channel quality range comprises:
a channel quality corresponding to the first MCS with a highest spectral efficiency in the first MCS table; and/or
a channel quality corresponding to the first MCS with a second highest spectral efficiency in the first MCS table.
8 . The method of claim 3 , wherein the command is transmitted to the terminal device in at least one of:
downlink control information;
medium access control control element; or
a radio resource control message.
9 . The method of claim 3 , wherein the command is transmitted to the terminal device further based on a prohibition timer.
10 . The method of claim 1 , wherein the first MCS comprises 64 Quadrature Amplitude Modulation (QAM) and the second MCS comprises 256 QAM.
11 . A network device, comprising:
a processor; and
a memory coupled to the processor, the memory containing instructions executable by said processor, wherein the network device is operative to:
determine that a terminal device supports a first modulation and coding scheme (MCS) and a second MCS;
transmit configuration information regarding a first bandwidth part associated with a first MCS table supporting the first MCS to the terminal device; and
transmit configuration information regarding a second bandwidth part associated with the second MCS table supporting the second MCS to the terminal device,
the first MCS table being different from the second MCS table;
determine a power reduction value of the terminal device;
when the power reduction value of the terminal device is greater than the maximum power reduction value related to the first MCS and smaller than the maximum power reduction value related to the second MCS, determine the terminal device as a MCS table switch candidate; and
when the power reduction value of the terminal device is not greater than the maximum power reduction value related to the first MCS, determine the terminal device as a non MCS table switch candidate.
12 . The network device according to claim 11 , wherein determining the power reduction value of the terminal device comprises:
obtaining a power class of the terminal device;
obtaining a maximum transmitter power value configured to the terminal device;
obtaining a maximum transmitter power value of the terminal device; and
determining the power reduction value of the terminal device based on the power class of the terminal device, the maximum transmitter power value configured to the terminal device and the maximum transmitter power value of the terminal device.
13 . The network device according to claim 11 , wherein the network device is further operative to:
determine channel quality between the network device and the terminal device; and
transmit a command to the terminal device to switch to the first bandwidth part or the second bandwidth part based on the channel quality between the network device and the terminal device.
14 . The network device according to claim 13 , wherein transmitting a command to the terminal device to switch to the first bandwidth part or the second bandwidth part based on the channel quality between the network device and the terminal device comprises:
determining that the terminal device is using the second MCS table; and
when the channel quality between the network device and the terminal device falls into at least one first channel quality range that network performance using the first MCS table is higher than network performance using the second MCS table, transmitting the command to the terminal device to switch to the first bandwidth part.