Certain aspects of the present disclosure relate to methods and apparatus for phase noise estimation in data symbols for millimeter wave (mmW). A method for wireless communications by a transmitting device is provided. The method generally includes identifying a phase noise metric associated with at least one receiving device; determining a phase noise pilot configuration based, at least in part, on the identified phase noise metric; and providing an indication of the phase noise pilot configuration to the at least one receiving device. A receiving device can receive the phase noise pilots in accordance with the configuration and determine phase noise for a data symbol based on the received phase noise pilots.

A method and apparatus are provided for determining a transmission mode. A method embodiment includes obtaining, by a terminal device, configuration indication information, the configuration indication information comprising one or more of: DMRS indication information, repeated-transmission indication information, or transmission configuration indication information; and determining a transmission mode based on the configuration indication information, the transmission mode is one or more of: a space division multiplexing mode, a frequency division multiplexing mode, or a time division multiplexing mode.

A method and an apparatus for transmitting/receiving a downlink signal in a wireless communication system are provided. Carrier information about a second carrier that is different from a first carrier can be transmitted on the first carrier. Downlink data for UE can be transmitted on the second carrier based on the carrier information. The first carrier is a carrier having a synchronisation signal and a physical broadcast channel, and the second carrier can be a carrier without any synchronisation signals or physical broadcast channels. The first carrier can be operated on a single resource block in a guard frequency that is used in the wireless communication system.

Provided are methods and devices for transmitting/receiving downlink signals in a Wireless communication system. Carrier information is provided to user equipment, the carrier information including cell identifier information which indicates Whether a first cell identifier related to a first carrier operating on one resource block (RB) and a second cell identifier used for a cell-specific reference signal (CRS) on the first carrier are the same or different. If the second cell identifier is the same as the first cell identifier, the user equipment assumes that the number of antenna ports for the CRS on the first carrier is the same as the number of antenna ports for a reference signal defined for NB-IoT (reference signal for NB-IoT, NRS). If the second cell identifier is different from the first cell identifier, the carrier information further includes antenna port number information, and the user equipment assumes that the number of the antenna ports for the CRS is the same as the number of antenna ports based on the antenna port number information.

Techniques are described for wireless communication. A method for wireless communication at a base station includes identifying time resources and frequency resources for narrowband communication in a plurality of subframes, identifying a plurality of user equipment (UE) devices, allocating a first portion of the time resources and the frequency resources to an uplink (UL) channel to carry UL control information, and allocating resources of the UL channel to the identified UE devices. A method for wireless communication at a UE device includes identifying time resources and frequency resources for narrowband communication in a plurality of subframes, receiving an indication of at least a first portion of the time resources and the frequency resources allocated to a UL channel to carry UL control information for the UE device, and transmitting one or both of downlink acknowledgements (ACKs) and downlink non-acknowledgements (NAKs) on the UL channel.

A method and an apparatus for transmitting/receiving a downlink signal in a wireless communication system are provided. Carrier information about a second carrier that is different from a first carrier can be transmitted on the first carrier. Downlink data for UE can be transmitted on the second carrier based on the carrier information. The first carrier is a carrier having a synchronisation signal and a physical broadcast channel, and the second carrier can be a carrier without any synchronisation signals or physical broadcast channels. The first carrier can be operated on a single resource block in a guard frequency that is used in the wireless communication system.

A method and an apparatus for transmitting/receiving a downlink signal in a wireless communication system are provided. Carrier information about a second carrier that is different from a first carrier can be transmitted on the first carrier. Downlink data for UE can be transmitted on the second carrier based on the carrier information. The first carrier is a carrier having a synchronisation signal and a physical broadcast channel, and the second carrier can be a carrier without any synchronisation signals or physical broadcast channels. The first carrier can be operated on a single resource block in a guard frequency that is used in the wireless communication system.

Provided are methods and devices for transmitting/receiving downlink signals in a Wireless communication system. Carrier information is provided to user equipment, the carrier information including cell identifier information which indicates Whether a first cell identifier related to a first carrier operating on one resource block (RB) and a second cell identifier used for a cell-specific reference signal (CRS) on the first carrier are the same or different. If the second cell identifier is the same as the first cell identifier, the user equipment assumes that the number of antenna ports for the CRS on the first carrier is the same as the number of antenna ports for a reference signal defined for NB-IoT (reference signal for NB-IoT, NRS). If the second cell identifier is different from the first cell identifier, the carrier information further includes antenna port number information, and the user equipment assumes that the number of the antenna ports for the CRS is the same as the number of antenna ports based on the antenna port number information.

Provided are methods and devices for transmitting/receiving downlink signals in a narrowband. A user equipment acquires a first cell identifier from a first carrier on which a narrowband synchronization signal (nSS) and a narrowband broadcast channel (nPBCH) are present. Carrier information for a second carrier on which the nSS and the PBCH are not present is provided to a user equipment. The user equipment receives downlink data on the second carrier based on the carrier information and a narrowband reference signal (NB-RS). The NB-RS is received based on the first cell identifier. Each of the first and second carriers operates in one resource block.

Certain aspects of the present disclosure relate to methods and apparatus for phase noise estimation in data symbols for millimeter wave (mmW). A method for wireless communications by a transmitting device is provided. The method generally includes identifying a phase noise metric associated with at least one receiving device; determining a phase noise pilot configuration based, at least in part, on the identified phase noise metric; and providing an indication of the phase noise pilot configuration to the at least one receiving device. A receiving device can receive the phase noise pilots in accordance with the configuration and determine phase noise for a data symbol based on the received phase noise pilots.