The present disclosure provides a method and device for multi-antenna transmission in UE and base station. The user equipment receives a first wireless signal at first; then transmits a second wireless signal, and monitors a first signaling in a first sub-time resource pool. Wherein the first wireless signal is transmitted by K antenna port group(s) and the second wireless signal is used to determine the first antenna port group. The first antenna port group is one of the K antenna port group(s). The first sub-time resource pool is reserved to the first antenna port group, or the index of the first antenna port group is used to determine the first sub-time resource pool. One antenna port group includes positive integer number of antenna ports, and the K is a positive integer greater than 1. The disclosure reduces the complexity of blind detection of downlink signaling by the UE.

The present disclosure provides a method and device for multi-antenna transmission in UE and base station. The user equipment receives a first wireless signal at first; then transmits a second wireless signal, and monitors a first signaling in a first sub-time resource pool. Wherein the first wireless signal is transmitted by K antenna port group(s) and the second wireless signal is used to determine the first antenna port group. The first antenna port group is one of the K antenna port group(s). The first sub-time resource pool is reserved to the first antenna port group, or the index of the first antenna port group is used to determine the first sub-time resource pool. One antenna port group includes positive integer number of antenna ports, and the K is a positive integer greater than 1. The disclosure reduces the complexity of blind detection of downlink signaling by the UE.

Example synchronization signal sending and receiving methods and apparatus are described. In one example method, a terminal device determines a target frequency resource. A frequency domain position of the target frequency resource is determined based on a frequency domain position offset and a frequency interval of synchronization channels. The terminal device receives a synchronization signal by using the target frequency resource.

Methods, systems, and devices for wireless communications are described for scheduled communications in which multiple different communication instances are scheduled between a user equipment (UE) and a base station. Different communication parameters for different communication instances may be selected based on reported channel conditions between the UE and the base station. Subsequent to a report of channel conditions results in chanced communication parameters, the UE may blind decode a one or more scheduled communications using multiple candidate sets of decoding hypotheses to identify a first candidate set of decoding parameters that is used for the first scheduled communication. Such techniques provide that communication parameters may be adjusted based on channel conditions, and a UE may decode a communication in the event that the base station does not successfully receive a measurement report and continues transmissions using a prior set of parameters.

Methods, systems, and devices for wireless communications are described. A base station may identify time and frequency resources for a physical downlink shared channel (PDSCH) to be transmitted to a user equipment (UE) in a first transmission time interval (TTI). The base station may transmit configuration information for a control channel search space set in a second TTI. The second TTI may precede the first TTI. The configuration information may include an indication of an absence of a physical downlink control channel (PDCCH) transmission to send in the control channel search space set indicating the identified time and frequency resources for the PDSCH, and a set of time and frequency resources for the control channel search space set. The UE may receive the configuration information and identify the time and frequency resources allocated for the PDSCH in the second TTI, and receive the PDSCH transmission in the second TTI.

Since multiple transmit-receive point (TRP) communications may increase the number of physical downlink control channel (PDCCH) candidates without increasing the number of cells, new limits for multi-TRP communications may be defined. A UE may determine a PDCCH monitoring capability across all downlink serving cells that may account for multiple-TRP cells and for carrier aggregation and dual connectivity using a multiplication factor for serving cells with two control resource set (CORESET) groups, for signaling a number representing PDCCH monitoring capability across all downlink serving cells. Further, the UE may determine limits of a number of serving cells based on the capability and a configuration of serving cells. The UE may determine a total limit and a per cell limit of PDCCH candidates and non-overlapped control channel elements (CCEs) to monitor in a slot for a cell group. The UE may perform blind decoding operations within the limits.

This application provides a synchronization signal sending method and receiving method, and an apparatus. In the method, a base station determines a frequency domain position of a target frequency resource based on a frequency interval of synchronization channels, wherein the frequency interval of synchronization channels is 2.sup.m times a predefined frequency resource of a physical resource block, and m is a preset nonnegative integer. The base station sends a synchronization signal by using the target frequency resource.

The present disclosure provides a method and device for multi-antenna transmission in UE and base station. The user equipment receives a first wireless signal at first; then transmits a second wireless signal, and monitors a first signaling in a first sub-time resource pool. Wherein the first wireless signal is transmitted by K antenna port group(s) and the second wireless signal is used to determine the first antenna port group. The first antenna port group is one of the K antenna port group(s). The first sub-time resource pool is reserved to the first antenna port group, or the index of the first antenna port group is used to determine the first sub-time resource pool. One antenna port group includes positive integer number of antenna ports, and the K is a positive integer greater than 1. The disclosure reduces the complexity of blind detection of downlink signaling by the UE.

Since multiple transmit-receive point (TRP) communications may increase the number of physical downlink control channel (PDCCH) candidates without increasing the number of cells, new limits for multi-TRP communications may be defined. A UE may determine a PDCCH monitoring capability across all downlink serving cells that may account for multiple-TRP cells and for carrier aggregation and dual connectivity using a multiplication factor for serving cells with two control resource set (CORESET) groups, for signaling a number representing PDCCH monitoring capability across all downlink serving cells. Further, the UE may determine limits of a number of serving cells based on the capability and a configuration of serving cells. The UE may determine a total limit and a per cell limit of PDCCH candidates and non-overlapped control channel elements (CCEs) to monitor in a slot for a cell group. The UE may perform blind decoding operations within the limits.

Methods, systems, and devices for wireless communications are described. A base station may identify time and frequency resources for a physical downlink shared channel (PDSCH) to be transmitted to a user equipment (UE) in a first transmission time interval (TTI). The base station may transmit configuration information for a control channel search space set in a second TTI. The second TTI may precede the first TTI. The configuration information may include an indication of an absence of a physical downlink control channel (PDCCH) transmission to send in the control channel search space set indicating the identified time and frequency resources for the PDSCH, and a set of time and frequency resources for the control channel search space set. The UE may receive the configuration information and identify the time and frequency resources allocated for the PDSCH in the second TTI, and receive the PDSCH transmission in the second TTI.