Disclosed are systems and methods in 5G and 6G, for compensating frequency shifts caused by the relative motion of a transmitter and receiver. For communication between a mobile user device and a base station, protocols can provide that the messages received by the base station comply with a predetermined channel frequency. Further protocols can provide that a mobile user device may transmit and receive messages at the same frequency. For sidelink communication, protocols can provide that peer devices can either transmit or receive at a predetermined channel frequency, greatly assisting reception of the messages.

Systems, methods, and devices can be utilized to selectively connect to a device via extremely high frequency (EHF) radio resources based on the velocity of the device. An example method includes receiving, from a user equipment (UE), a first wireless signal with a first frequency that is less than 30 Gigahertz (GHz). The example method further includes determining a velocity of the UE based on the first wireless signal and determining that the velocity of the UE is less than a threshold velocity. Based on determining that the velocity of the UE is less than the threshold velocity, a second wireless signal is transmitted to the UE with a second frequency that is greater than or equal to 30 GHz.

Systems, methods, and devices can be utilized to selectively connect to a device via extremely high frequency (EHF) radio resources based on the velocity of the device. An example method includes receiving, from a user equipment (UE), a first wireless signal with a first frequency that is less than 30 Gigahertz (GHz). The example method further includes determining a velocity of the UE based on the first wireless signal and determining that the velocity of the UE is less than a threshold velocity. Based on determining that the velocity of the UE is less than the threshold velocity, a second wireless signal is transmitted to the UE with a second frequency that is greater than or equal to 30 GHz.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may retune from a first narrowband carrier to a second narrowband carrier. The UE may determine to retune in one or more symbols of either a first narrowband subframe or a second narrowband subframe based on the number of symbols for the UE to retune and a number of other factors. The other factors may include the start symbol of a downlink channel scheduled in the second narrowband subframe, the number of antenna ports configured for the UE, hybrid automatic repeat request (HARQ) identifier (ID), coding rate or effective coding rate, among others. The UE may determine to retune in the first narrowband subframe, the second narrowband subframe, or in both subframes in order to utilize reference signals transmitted to the UE and reception of all downlink messages scheduled for the UE.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may retune from a first narrowband carrier to a second narrowband carrier. The UE may determine to retune in one or more symbols of either a first narrowband subframe or a second narrowband subframe based on the number of symbols for the UE to retune and a number of other factors. The other factors may include the start symbol of a downlink channel scheduled in the second narrowband subframe, the number of antenna ports configured for the UE, hybrid automatic repeat request (HARQ) identifier (ID), coding rate or effective coding rate, among others. The UE may determine to retune in the first narrowband subframe, the second narrowband subframe, or in both subframes in order to utilize reference signals transmitted to the UE and reception of all downlink messages scheduled for the UE.

A system and method for determining SFN using QCL information is disclosed. In one aspect, a method receiving, by a wireless communication device, a first set of quasi-co-location (QCL) information; receiving, by the wireless communication device, a transmission; and applying, by the wireless communication device, a second set of QCL information based on the first set of QCL information, wherein the second set of QCL information is different from the first set of QCL information.

A system and method for determining SFN using QCL information is disclosed. In one aspect, a method receiving, by a wireless communication device, a first set of quasi-co-location (QCL) information; receiving, by the wireless communication device, a transmission; and applying, by the wireless communication device, a second set of QCL information based on the first set of QCL information, wherein the second set of QCL information is different from the first set of QCL information.

This application provides a phase correction method and a communication apparatus. In the phase correction method, a network device sends a combined signal to a terminal, where the combined signal is obtained by passing a first signal through N channels and combining output signals of the N channels. The terminal determines a precoding matrix based on the combined signal and feeds back the precoding matrix to the network device. The network device estimates a phase error between a plurality of channels of the network device based on the precoding matrix, and corrects phases of the N channels based on the obtained phase error. In the foregoing technical solution, soft correction of phases of N channels of the network device may be implemented by using an air interface feedback of a terminal, so that it can be ensured that the phases of the N channels are consistent.

This application provides a phase correction method and a communication apparatus. In the phase correction method, a network device sends a combined signal to a terminal, where the combined signal is obtained by passing a first signal through N channels and combining output signals of the N channels. The terminal determines a precoding matrix based on the combined signal and feeds back the precoding matrix to the network device. The network device estimates a phase error between a plurality of channels of the network device based on the precoding matrix, and corrects phases of the N channels based on the obtained phase error. In the foregoing technical solution, soft correction of phases of N channels of the network device may be implemented by using an air interface feedback of a terminal, so that it can be ensured that the phases of the N channels are consistent.

Aspects herein describe increasing density of reference signal transmissions in wireless communications. A plurality of reference signal configurations, each indicating resource elements for one or more antenna ports over which reference signals for the one or more antenna ports are scheduled for transmission, can be received. An association configuration indicating an association between at least two antenna ports as having similar channel characteristics can also be received. A plurality of reference signals can be received in the resource elements corresponding to the at least two antenna ports as indicated in the at least two of the plurality of reference signal configurations, which can be used to perform a channel measurement of the similar channel characteristics of channels of the at least two antenna ports over at least a portion of the plurality of reference signals.