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.

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 signal sending method, a signal receiving method, and a device. The signal sending method includes: generating synchronization signals, where the synchronization signals include a first synchronization signal and a second synchronization signal; and sending the synchronization signals, where the first synchronization signal and the second synchronization signal overlap in time domain, and within a time domain resource in which the first synchronization signal and the second synchronization signal overlap, there is an intersection set between a frequency domain resource corresponding to the first synchronization signal and a frequency domain resource corresponding to the second synchronization signal. In this way, frequency domain resources occupied by the synchronization signals may be reduced, thereby saving frequency domain resources for another data transmission process. In addition, the two synchronization signals may further share a part of the frequency domain resources, thereby improving resource utilization.

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.

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.

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 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.