Method and user equipment for transmitting uplink control information
A user equipment (UE) transmits uplink control information (UCI) of 3 bits or more to a base station (BS) after modulating the UCI into 1-bit or 2-bit sub-UCI units. Here, the UE maps each 1-bit or 2-bit sub-UCI unit to one of a plurality of corner constellation points regardless of modulation order of data which is multiplexed with the UCI. The corner constellation points are points having a maximum Euclidean distance from among a plurality of constellation points corresponding to the modulation order.
1. A method for transmitting n-bit uplink control information (UCI) from a user equipment in a wireless communication system, where n is a positive integer equal to or greater than 3, the method comprising:
dividing the n-bit UCI into ceiling (n/2) sub-groups;
encoding each of the sub-groups according to a table having the form:
Q m
Encoded UCI
2
[o n UCI o n+1 UCI o n UCI o n+1 UCI o n+2 UCI o n+2 UCI ]
4
[o n UCI o n+1 UCI x x o n UCI o n+1 UCI x x o n+2 UCI o n+2 UCI x x]
6
[o n UCI o n+1 UCI x x x x o n UCI o n+1 UCI x x x x o n+2 UCI o n+2 UCI x x x x];
and
transmitting the encoded UCI on a physical uplink data channel that carries the UCI,
wherein Q m represents a modulation order of uplink data,
wherein the modulation order is QPSK (Quadrature Phase Shift Keying), 16QAM (16-Quadrature Amplitude Modulation) or 64QAM(64-QAM) when a value of Q m is 2, 4 or 6 respectively,
wherein o n UCI represents the n th bit of a predefined input bit sequence o UCI ,
wherein the o n+2 UCI is equal to (o n UCI +o n+1 UCI ) mod 2, and
wherein ‘x’ represents a placeholder for maximizing Euclidean distance of modulation symbols that carries each of the sub-groups when bits of each of the sub-groups are scrambled.
2. The method according to claim 1 , wherein each of the sub-groups is mapped to one of 4 constellation points that are close to a unit power circle of QPSK and maximize the Euclidean distance among a plurality of constellation points according to the modulation order.
3. The method according to claim 1 , wherein the UCI is ACK/NACK (acknowledgement/negative ACK) or RI (Rank Information).
4. The method according to claim 3 , wherein the UCI with a bit sequence of [o 0 UCI o 1 UCI , . . . , o O UCI −1 UCI ] is divided into sub groups of [{o 0 UCI o 1 UCI }, {o 2 UCI o 3 UCI }, . . . , {o O UCI −1 UCI }] when n is an odd number.
5. The method according to claim 3 , the UCI with a bit sequence of [o 0 UCI o 1 UCI , . . . , o O UCI −1 UCI ] is divided into sub-groups of [{o 0 UCI o 1 UCI }, {o 2 UCI o 3 UCI }, . . . , {o O UCI −1 UCI y}] when n is an odd number, and wherein y represents a predefined bit 0 , 1 or o O UCI −1 UCI .
6. A user equipment for transmitting n-bit uplink control information (UCI) in a wireless communication system, where n is a positive integer equal to or greater than 3, the user equipment comprising:
a transmitter; and
a processor, electrically connected to the transmitter, configured to control the transmitter,
wherein the processor divides the n-bit uplink control information into ceiling(n/2) sub-groups, encodes each of the sub-groups according to a table having the form:
Q m
Encoded UCI
2
[o n UCI o n+1 UCI o n UCI o n+1 UCI o n+2 UCI o n+2 UCI ]
4
[o n UCI o n+1 UCI x x o n UCI o n+1 UCI x x o n+2 UCI o n+2 UCI x x]
6
[o n UCI o n+1 UCI x x x x o n UCI o n+1 UCI x x x x o n+2 UCI o n+2 UCI x x x x],
, and controls the transmitter to transmit encoded UCI on a physical uplink data channel that carries the UCI,
wherein Q m represents a modulation order of uplink data,
wherein the modulation order is QPSK(Quadrature Phase Shift Keying), 16QAM(16-Quadrature Amplitude Modulation) or 64QAM(64-QAM) when a value of Q m is 2, 4 or 6 respectively,
wherein o n UCI represents the n th bit of a predefined input bit sequence o UCI ,
wherein the o n+2 UCI is equal to (o n UCI +o n+1 UCI ) mod 2, and
wherein ‘x’ represents a placeholder for maximizing Euclidean distance of modulation symbols that carries each of the sub-groups when bits of each of the sub-groups are scrambled.
7. The user equipment according to claim 6 , wherein each of the sub-groups is mapped to one of 4 constellation points that are close to a unit power circle of QPSK and maximize the Euclidean distance among a plurality of constellation points according to the modulation order.
8. The user equipment according to claim 6 , wherein the UCI is ACK/NACK(acknowledgement/negative ACK) or RI (Rank Information).
9. The user equipment according to claim 6 , wherein the UCI with a bit sequence of [o 0 UCI o 1 UCI , . . . , o O UCI −1 UCI ] is divided into sub-groups of [{o 0 UCI o 1 UCI }, {o 2 UCI o 3 UCI }, . . . , {o O UCI −1 UCI }] when n is an odd number.
10. The user equipment according to claim 6 , wherein the UCI with a bit sequence of [o 0 UCI o 1 UCI , . . . , o O UCI −1 UCI ] is divided into sub-groups of [{o 0 UCI o 1 UCI }, {o 2 UCI o 3 UCI }, . . . , {o O UCI −1 UCI y}] when n is an odd number, and
wherein y represents a predefined bit 0 , 1 or o O UCI −1 UCI .