Systems and methods for constellation superposition
A method for performing constellation superposition by an evolved Node B (eNB) includes determining an admissible data constellation for a second user equipment (UE) based on a data constellation of a first UE. The first UE and the second UE share the same time-frequency resources. The method also includes sending an indication that superposition coded modulation is being employed by the first UE and the second UE. The method further includes sending modulation and coding schemes (MCSs) and/or transmission power percentages used by each of the first UE and the second UE to the other UE.
1. A user equipment (UE) comprising:
physical downlink control channel (PDCCH) receiving circuitry configured to receive a PDCCH with a downlink control information (DCI) format; and
physical downlink shared channel (PDSCH) receiving circuitry configured to receive a PDSCH upon the detection of the PDCCH; wherein
the DCI format has a 5-bit information field and a 2-bit information field in which the 5-bit information field indicates one of at least a first modulation scheme and a second modulation scheme of the UE, the 2-bit information field indicates multiuser superposition transmission (MUST) interference presence and power ratio, and the power ratio is a ratio of power of the UE,
in a case that the 2-bit information field is not set to ‘00’ and the 5-bit information field indicates the first modulation scheme, a first table is used for determining the power ratio, the first table including a value ‘01’ set by the 2-bit information field, a value ‘10’ set by the 2-bit information field, a value ‘11’ set by the 2-bit information field, a first power ratio corresponding to the value ‘01’, a second power ratio corresponding to the value ‘10’, and a third power ratio corresponding to the value ‘11’, and
in a case that the 2-bit information field is not set to ‘00’ and the 5-bit information field indicates the second modulation scheme, a second table is used for determining the power ratio, the second table including the value ‘01’ set by the 2-bit information field, the value ‘10’ set by the 2-bit information field, the value ‘11’ set by the 2-bit information field, a fourth power ratio corresponding to the value ‘01’, a fifth power ratio corresponding to the value ‘10’, and a sixth power ratio corresponding to the value ‘11’, the fourth power ratio being different from the first power ratio, the fifth power ratio being different from the second power ratio, and the sixth power ratio being different from the third power ratio.
2. The UE according to claim 1 , wherein based on the values and the modulation scheme, the UE demodulates the PDSCH as the UE's own received data.
3. The UE according to claim 1 , wherein in a case that the 2-bit information field is set to ‘00’, correspondence between values indicated by the 2-bit information field and power ratios does not depend on the modulation scheme.
4. The UE according to claim 3 , wherein based on the values and the modulation scheme, the UE demodulates the PDSCH as the UE's own received data.
5. The UE according to claim 1 , wherein in a case that the 2-bit information field is set to ‘00’, the UE assumes that MUST interference is not present.
6. An evolved node B (eNB) communicating with a user equipment (UE), the eNB comprising:
physical downlink control channel (PDCCH) transmitting circuitry configured to transmit the PDCCH with a downlink control information (DCI) format; and
physical downlink shared channel (PDSCH) transmitting circuitry configured to transmit a PDSCH; wherein
the DCI format has a 5-bit information field and a 2-bit information field in which the 5-bit information field indicates one of at least a first modulation scheme and a second modulation scheme of the UE, the 2-bit information field indicates multiuser superposition transmission (MUST) interference presence and power ratio, and the power ratio is a ratio of power of the UE,
in a case that the 2-bit information field is not set to ‘00’ and the 5-bit information field indicates the first modulation scheme, a first table is used for determining the power ratio, the first table including a value ‘01’ set by the 2-bit information field, a value ‘10’ set by the 2-bit information field, a value ‘11’ set by the 2-bit information field, a first power ratio corresponding to the value ‘01’, a second power ratio corresponding to the value ‘10’ and a third power ratio corresponding to the value ‘11’, and
in a case that the 2-bit information field is not set to ‘00’ and the 5-bit information field indicates the second modulation scheme, a second table is used for determining the power ratio, the second table including the value ‘01’ set by the 2-bit information field, the value ‘10’ set by the 2-bit information field, the value ‘11’ set by the 2-bit information field, a fourth power ratio corresponding to the value ‘01’, a fifth power ratio corresponding to the value ‘10’ and a sixth power ratio corresponding to the value ‘11’, the fourth power ratio being different from the first power ratio, the fifth power ratio being different from the second power ratio, and the sixth power ratio being different from the third power ratio.
7. The eNB according to claim 6 , wherein in a case that the 2-bit information field is set to ‘00’, correspondence between values indicated by the 2-bit information field and power ratios does not depend on the modulation scheme.
8. The eNB according to claim 6 , wherein in a case that the 2-bit information field is set to ‘00’, the eNB does not perform MUST multiplexing.
9. A method for a user equipment (UE), the method comprising:
receiving a physical downlink control channel (PDCCH) with a downlink control information (DCI) format; and
receiving a physical downlink shared channel (PDSCH) upon the detection of the PDCCH; wherein
the DCI format has a 5-bit information field and a 2-bit information field in which the 5-bit information field indicates one of at least a first modulation scheme and a second modulation scheme of the UE, the 2-bit information field indicates multiuser superposition transmission (MUST) interference presence and power ratio, and the power ratio is a ratio of power of the UE,
in a case that the 2-bit information field is not set to ‘00’ and the 5-bit information field indicates the first modulation scheme, a first table is used for determining the power ratio, the first table including a value ‘01’ set by the 2-bit information field, a value ‘10’ set by the 2-bit information field, a value ‘11’ set by the 2-bit information field, a first power ratio corresponding to the value ‘01’, a second power ratio corresponding to the value ‘10’ and a third power ratio corresponding to the value ‘11’, and
in a case that the 2-bit information field is not set to ‘00’ and the 5-bit information field indicates the second modulation scheme, a second table is used for determining the power ratio, the second table including the value ‘01’ set by the 2-bit information field, the value ‘10’ set by the 2-bit information field, the value ‘11’ set by the 2-bit information field, a fourth power ratio corresponding to the value ‘01’, a fifth power ratio corresponding to the value ‘10’ and a sixth power ratio corresponding to the value ‘11’, the fourth power ratio being different from the first power ratio, the fifth power ratio being different from the second power ratio, and the sixth power ratio being different from the third power ratio.
10. The method according to claim 9 , wherein in a case that the 2-bit information field is set to ‘00’, correspondence between values indicated by the 2-bit information field and power ratios does not depend on the modulation scheme.
11. A method for an evolved node B (eNB) communicating with a user equipment (UE), the eNB comprising:
transmitting a physical downlink control channel (PDCCH) with a downlink control information (DCI) format; and
transmitting a physical downlink shared channel (PDSCH) upon the detection of the PDCCH; wherein
the DCI format has a 5-bit information field and a 2-bit information field in which the 5-bit information field indicates one of at least a first modulation scheme and a second modulation scheme of the UE, the 2-bit information field indicates multiuser superposition transmission (MUST) interference presence and power ratio, and the power ratio is a ratio of power of the UE,
in a case that the 2-bit information field is not set to ‘00’ and the 5-bit information field indicates the first modulation scheme, a first table is used for determining the power ratio, the first table including a value ‘01’ set by the 2-bit information field, a value ‘10’ set by the 2-bit information field, a value ‘11’ set by the 2-bit information field, a first power ratio corresponding to the value ‘01’, a second power ratio corresponding to the value ‘10’, and a third power ratio corresponding to the value ‘11’, and
in a case that the 2-bit information field is not set to ‘00’ and the 5-bit information field indicates the second modulation scheme, a second table is used for determining the power ratio, the second table including the value ‘01’ set by the 2-bit information field, the value ‘10’ set by the 2-bit information field, the value ‘11’ set by the 2-bit information field, a fourth power ratio corresponding to the value ‘01’, a fifth power ratio corresponding to the value ‘10’, and a sixth power ratio corresponding to the value ‘11’, the fourth power ratio being different from the first power ratio, the fifth power ratio being different from the second power ratio, and the sixth power ratio being different from the third power ratio.
12. The method according to claim 11 , wherein in a case that the 2-bit information field is set to ‘00’, correspondence between values indicated by the 2-bit information field and power ratios does not depend on the modulation scheme.