Method for performing HARQ operation in NoMA based system and apparatus therefor
A method in which a terminal performs a HARQ operation in a NoMA-based system comprises a step of receiving a downlink control information (dci) format comprising a multiple access (MA) signature field for supporting NoMA transmission; a step of receiving downlink data based on a value of the MA signature indicated by the MA signature field; and a step of transmitting an ACK/NACK signal with respect to the downlink data based on a subframe offset value, a frequency offset value, or a sequence index value, which are tied with the indicated value of the MA signature according to a predefined rule, wherein the subframe offset value comprises the subframe offset value between a reception subframe of the downlink data and a downlink HARQ feedback transmission subframe with respect to the downlink data, and wherein the frequency offset value indicates a frequency band used for transmitting the ACK/NACK signal.
1. A method of performing a hybrid automatic repeat request (HARQ) operation by a user equipment (UE) in a non-orthogonal multiple access (NoMA) based system, the method comprising:
receiving a downlink control information (DCI) format including a multiple access (MA) signature field for supporting NoMA transmission;
receiving downlink data based on a value of an MA signature indicated by the MA signature field; and
transmitting an acknowledgement/negative acknowledgement (ACK/NACK) signal for the downlink data based on a subframe offset value, a frequency offset value, or a sequence index value tied to the value of the indicated MA signature according to a predetermined rule,
wherein the subframe offset value comprises a subframe offset value between a subframe in which the downlink data is received and a subframe in which the downlink HARQ feedback for the downlink data is transmitted, and
wherein the frequency offset value indicates a frequency band for transmitting the ACK/NACK signal.
2. The method of claim 1 , wherein the MA signature comprises a codeword index, a codebook index, an interleaver index, a demodulation reference signal index, a spatial dimension, or a power dimension.
3. The method of claim 1 , wherein the ACK/NACK signal is transmitted further based on a number of a control channel element (CCE) on which the MA signature field is transmitted according to the predetermined rule.
4. The method of claim 1 , wherein the ACK/NACK signal is transmitted in the subframe indicated by the subframe offset value tied to the value of the indicated MA signature.
5. The method of claim 1 , wherein the ACK/NACK signal is transmitted in the frequency band indicated by the frequency offset value tied to the value of the indicated MA signature.
6. The method of claim 1 , wherein the ACK/NACK signal is transmitted by applying a sequence corresponding to the sequence index value tied to the value of the indicated MA signature to the ACK/NACK signal.
7. The method of claim 1 , wherein the MA signature field is a 2-bit field.
8. A user equipment (UE) for performing a hybrid automatic repeat request (HARQ) operation in a non-orthogonal multiple access (NoMA) based system, the UE comprising:
a receiver;
a transmitter; and
a processor,
wherein the processor is configured to:
control the receiver to receive a downlink control information (DCI) format including a multiple access (MA) signature field for supporting NoMA transmission and receive downlink data based on a value of an MA signature indicated by the MA signature field; and
perform control to transmit an acknowledgement/negative acknowledgement (ACK/NACK) signal for the downlink data based on a subframe offset value, a frequency offset value, or a sequence index value tied to the value of the indicated MA signature according to a predetermined rule,
wherein the subframe offset value comprises a subframe offset value between a subframe in which the downlink data is received and a subframe in which the downlink HARQ feedback for the downlink data is transmitted, and
wherein the frequency offset value indicates a frequency band for transmitting the ACK/NACK signal.
9. The UE of claim 8 , wherein the MA signature comprises a codeword index, a codebook index, an interleaver index, a demodulation reference signal index, a spatial dimension, or a power dimension.
10. The UE of claim 8 , wherein the processor is configured to control the transmitter to transmit the ACK/NACK signal further based on a number of a control channel element (CCE) on which the MA signature field is transmitted according to the predetermined rule.
11. The UE of claim 8 , wherein the processor is configured to control the transmitter to transmit the ACK/NACK signal in the subframe indicated by the subframe offset value tied to the value of the indicated MA signature.
12. The UE of claim 8 , wherein the processor is configured to control the transmitter to transmit the ACK/NACK signal in the frequency band indicated by the frequency offset value tied to the value of the indicated MA signature.
13. The UE of claim 8 , wherein the processor is configured to:
apply a sequence corresponding to the sequence index value tied to the value of the indicated MA signature to the ACK/NACK signal; and
control the transmitter to transmit the ACK/NACK signal to which the sequence is applied.
14. The UE of claim 8 , wherein the MA signature field is a 2-bit field.