Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive a demodulation reference signal (DMRS) configuration that indicates a code-division multiplexing (CDM) group configured for the UE; receive a first indication of an antenna port, included in the CDM group, assigned to the UE for reception of a first set of DMRS transmissions; receive a second indication of whether a second set of DMRS transmissions for another antenna port, included in the CDM group, is present or absent for another UE; and perform channel estimation based at least in part on the first indication of the antenna port and the second indication of whether the second set of DMRS transmissions for the other antenna port is present or absent. Numerous other aspects are provided.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive a demodulation reference signal (DMRS) configuration that indicates a code-division multiplexing (CDM) group configured for the UE; receive a first indication of an antenna port, included in the CDM group, assigned to the UE for reception of a first set of DMRS transmissions; receive a second indication of whether a second set of DMRS transmissions for another antenna port, included in the CDM group, is present or absent for another UE; and perform channel estimation based at least in part on the first indication of the antenna port and the second indication of whether the second set of DMRS transmissions for the other antenna port is present or absent. Numerous other aspects are provided.

Provided are a method by which a terminal performs decoding in a wireless communication system, and a device. According to the present disclosure, provided are a method and a device, which: receive, from a base station through a DMRS symbol, a demodulation reference signal (DMRS) set according to a specific pattern by the base station, wherein the demodulation reference signal is transmitted in a specific antenna port and positioned on one or two time axis symbols, which are the same as at least one other o demodulation reference signal transmitted in another antenna port; and decode data by using the demodulation reference signal.

Provided are a method by which a terminal performs decoding in a wireless communication system, and a device. According to the present disclosure, provided are a method and a device, which: receive, from a base station through a DMRS symbol, a demodulation reference signal (DMRS) set according to a specific pattern by the base station, wherein the demodulation reference signal is transmitted in a specific antenna port and positioned on one or two time axis symbols, which are the same as at least one other o demodulation reference signal transmitted in another antenna port; and decode data by using the demodulation reference signal.

Methods, systems, and devices for the design of symbol-group based spreading schemes are described. An exemplary method for wireless communication includes transmitting, by a terminal, a first spread signal that is generated by spreading a first group of N data symbols using a first set of N sequences, where N is a symbol-group length, L is a spreading length, each of the first set of N sequences is from an orthogonal spreading sequence set that comprises L sequences, and each of the L sequences is of length L. Another exemplary method for wireless communication includes transmitting, by a network node, an indication of a first set of N sequences, and receiving a first spread signal comprising a group of N data symbols spread using the first set of N sequences.

The present disclosure provides a terminal device that allows constraints on user allocation to be prevented and spread codes to be allocated in a scheduler when non-adaptive HARQ is employed using a PHICH. A codeword generator generates code words by encoding data, a layer mapping unit places each CW in one or a plurality of layers, a DMRS generator generates a reference signal for each layer in which a CW is placed by using any resource among a plurality of resources defined by a mutually orthogonal plurality of OCCs, and an ACK/NACK demodulator receives a response signal indicating a retransmission request. When a response signal requesting retransmission of only a CW placed in a plurality of layers is received, the DMRS generator uses each resource having the same OCC among the plurality of resources for the reference signals generated in the corresponding layers.

The present disclosure provides a terminal device that allows constraints on user allocation to be prevented and spread codes to be allocated in a scheduler when non-adaptive HARQ is employed using a PHICH. A codeword generator generates code words by encoding data, a layer mapping unit places each CW in one or a plurality of layers, a DMRS generator generates a reference signal for each layer in which a CW is placed by using any resource among a plurality of resources defined by a mutually orthogonal plurality of OCCs, and an ACK/NACK demodulator receives a response signal indicating a retransmission request. When a response signal requesting retransmission of only a CW placed in a plurality of layers is received, the DMRS generator uses each resource having the same OCC among the plurality of resources for the reference signals generated in the corresponding layers.

Communication is performed by using an uplink control channel of a configuration matching each shortened TTI. A user terminal according to the present invention includes: a transmission section that transmits uplink control information via an uplink control channel by using a shortened TTI configured by a smaller number of symbols than symbols of a normal TTI; and a control section that controls the transmission of the uplink control information, and the control section transmits the uplink control information by using a resource block subjected to frequency hopping between slots in the second TTI, and maps a demodulation reference signal on at least one symbol that configures the slots.

Communication is performed by using an uplink control channel of a configuration matching each shortened TTI. A user terminal according to the present invention includes: a transmission section that transmits uplink control information via an uplink control channel by using a shortened TTI configured by a smaller number of symbols than symbols of a normal TTI; and a control section that controls the transmission of the uplink control information, and the control section transmits the uplink control information by using a resource block subjected to frequency hopping between slots in the second TTI, and maps a demodulation reference signal on at least one symbol that configures the slots.

A repeater generates repetition signals by repeating an uplink signal over a plurality of subframes. If the plurality of subframes do not include a transmission candidate subframe of a sounding reference signal used to measure uplink reception quality, a controller sets a first transmission format to all the plurality of subframes, and if the plurality of subframes include the transmission candidate subframe, the controller sets a second transmission format to all the plurality of subframes. A transmitter transmits the repetition signals using the set transmission format.