Method and apparatus for transmitting uplink signal in wireless communication system
The present invention relates to a wireless communication system and, more specifically, to a method and an apparatus for transmitting an uplink signal. The method for transmitting an uplink signal from a terminal in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: receiving configuration information about candidates in a parameter set for a reference signal for physical uplink shared channel (PUSCH) modulation; receiving information indicating a specific set among the candidates in the parameter set; and generating a sequence of the reference signal using the specific set and transmitting the generated reference signal to a base station, wherein the information indicating the specific set may have a maximum value of the minimum distance between a circular shift index of the reference signal generated by a terminal using the specific set and a circular shift index of a reference signal generated by another terminal using the specific set.
1. A method of transmitting, by a user equipment (UE), an uplink signal in a wireless access system, the method comprising:
receiving configuration information regarding a plurality of parameter set candidates related to a reference signal for demodulation of a physical uplink shared channel (PUSCH);
receiving downlink control information (DCI) including a predetermined field set to a specific index from among a plurality of indices, the specific index indicating a specific cyclic shift (CS) set from among a plurality of CS sets, a specific orthogonal cover code (OCC) set from among a plurality of OCC sets and a specific parameter set from among the plurality of parameter set candidates;
generating a sequence of the reference signal using the specific CS set, the specific OCC set and the specific parameter set and transmitting the generated reference signal sequence to a base station (BS),
wherein the plurality of parameter set candidates have a mapping relation to the plurality of CS sets and the plurality of OCC sets such that a minimum distance between CS parameters for a layer in CS sets to which a same parameter set candidate among the plurality of parameter set candidates is mapped is maximized, and
wherein the specific parameter set includes information on each of:
a virtual cell ID (VCI) used for the generation of the reference signal sequence,
an offset parameter Δ ss between a sequence shift pattern of a physical uplink control channel (PUCCH) demodulation reference signal (DMRS) and a sequence shift pattern of the PUSCH DMRS,
an initial value c init CSH of a pseudo-random sequence which determines a cyclic shift hopping pattern of the PUSCH DMRS, a first CS parameter n DMRS (1) used to determine a CS index for the reference signal, and
an offset Δn DMRS used to determine the CS index.
2. The method according to claim 1 , wherein the predetermined field is a demodulation reference signal (DMRS) cyclic shift (CS) and orthogonal cover code (OCC) field.
3. The method according to claim 1 , wherein whether the predetermined field indicates the specific parameter set is configured by a higher layer.
4. The method according to claim 1 , wherein the information regarding the plurality of parameter set candidates is UE-specifically or UE-group-specifically signaled by a higher layer.
5. The method according to claim 1 , wherein the specific parameter set is independently configured per layer of the UE.
6. The method according to claim 1 , wherein the UE is paired with another UE for multiple user MIMO (MU-MIMO).
7. The method according to claim 1 , wherein the reference signal is transmitted on one SC-FDMA (single carrier frequency division multiple access) symbol in a slot in which the PUSCH is transmitted.
8. A user equipment (UE) of transmitting an uplink signal, comprising:
a receiver;
a transmitter; and
a processor configured to:
receive configuration information regarding a plurality of parameter set candidates related to a reference signal for demodulation of a physical uplink shared channel (PUSCH) via the receiver,
receive downlink control information (DCI) including a predetermined field set to a specific index from among a plurality of indices, the specific index indicating a specific cyclic shift (CS) set from among a plurality of CS sets, a specific orthogonal cover code (OCC) set from among a plurality of OCC sets and a specific parameter set from among the plurality of parameter set candidates via the receiver,
generate a sequence of the reference signal using the specific CS set, the specific OCC set and the specific parameter set, and
transmit the generated reference signal sequence to a BS via the transmitter,
wherein the plurality of parameter set candidates have a mapping relation to the plurality of CS sets and the plurality of OCC sets such that a minimum distance between CS parameters for a layer in CS sets to which a same parameter set candidate among the plurality of parameter set candidates is mapped is maximized, and
wherein the specific parameter set includes information on each of:
a virtual cell ID (VCI) used for the generation of the reference signal sequence,
an offset parameter Δ ss between a sequence shift pattern of a physical uplink control channel (PUCCH) demodulation reference signal (DMRS) and a sequence shift pattern of the PUSCH DMRS,
an initial value c init CSH of a pseudo-random sequence which determines a cyclic shift hopping pattern of the PUSCH DMRS, a first CS parameter n DMRS (1) used to determine a CS index for the reference signal, and
an offset Δn DMRS used to determine the CS index.
9. The method according to claim 1 , wherein each of the plurality of OCC sets includes OCCs applied to the reference signal for up to 4 layers.
10. The method according to claim 1 , wherein each of the plurality of CS sets includes second CS parameters for up to 4 layers used for determining the CS value for the reference signal.
11. The user equipment according to claim 8 , wherein the predetermined field is a demodulation reference signal (DMRS) cyclic shift (CS) and orthogonal cover code (OCC) field.
12. The user equipment according to claim 8 , wherein whether the predetermined field indicates the specific parameter set is configured by a higher layer.
13. The user equipment according to claim 8 , wherein the information regarding the plurality of parameter set candidates is UE-specifically or UE-group-specifically signaled by a higher layer.
14. The user equipment according to claim 8 , wherein the specific parameter set is independently configured per layer of the UE.
15. The user equipment according to claim 8 , wherein the UE is paired with another UE for multiple user MIMO (MU-MIMO).
16. The user equipment according to claim 8 , wherein the reference signal is transmitted on one SC-FDMA (single carrier frequency division multiple access) symbol in a slot in which the PUSCH is transmitted.
17. The user equipment according to claim 8 , wherein each of the plurality of OCC sets includes OCCs applied to the reference signal for up to 4 layers.
18. The user equipment according to claim 8 , wherein each of the plurality of CS sets includes second CS parameters for up to 4 layers used for determining the CS value for the reference signal.