The present disclosure provides a method and a device in a User Equipment (UE) and a base station for wireless communications. A UE receives first information, the first information being used for indicating M DCI blind decoding(s); monitors a first-type radio signal respectively on each of S sub-band(s) in a first time-domain resource; and performs at most M1 DCI blind decoding(s) of the M DCI blind decoding(s) on the S sub-band(s) in the first time-domain resource. Herein, the first-type radio signal detected on the S sub-band(s) is used for determining the M1 DCI blind decoding(s) out of the M DCI blind decoding(s). The above method allows the base station to make dynamic adjustments to the UE's blind decoding on PDCCH resources according to LBT results, ensuring that sufficient PDCCH resources are available and not too many PDSCH resources are preempted, and that excessive blind decodings can be avoided.

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.

A transmission method is provided for a communication system in which communications using a plurality of communication methods having different transmission parameters are performed at the same frequency (in frequency bands that at least partially overlap with each other). The transmission method includes: generating a first symbol group that includes a control symbol for causing a communication partner apparatus to recognize that communication using a first communication method is to be performed and a second symbol group that includes a data symbol for the first communication method; transmitting the first symbol group at a first transmit power; and transmitting the second symbol group at a second transmit power that is smaller than the first transmit power.

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 a monitoring capability for a first control resource set (CORESET) group and a second CORESET group. 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 for the first CORESET group and for the second CORESET group. The UE may perform blind decoding operations within the limits.

Systems and methods for canceling carrier frequency offset (CFO) and sampling frequency offset (SFO) in a radio receive chain are disclosed. In one embodiment, a method is disclosed, comprising: receiving a sub-frame via a radio receive chain in a time domain; performing per-user filtering on the sub-frame to obtain a signal for a particular user; obtaining a CFO correction signal; adding the CFO correction signal in the time domain to perform a CFO correction step on the signal for the particular user; performing an FFT on the output of the CFO correction step to obtain samples in a frequency domain; adding an SFO correction signal in the frequency domain to perform an SFO correction to the output of FFT step; and demodulating the output of SFO correction step, thereby performing CFO and SFO correction while reducing inter-carrier interference (ICI).

A method by which a terminal receives downlink control information in a wireless communication system includes: receiving a reference signal for a control channel by a search space set in a control resource set; and receiving downlink control information of the control channel on the basis of the reference signal. The search space includes a plurality of control channel candidates respectively corresponding to one or at least two CCEs according to an aggregation level, the one or at least two CCEs respectively include a plurality of REGs, and the terminal performs blind detection for each of the plurality of control channel candidates, and it can be assumed that a reference signal for a predetermined control channel candidate, for which blind detection is currently being performed, is mapped to a first REG firstly located in a time domain among REGs included in the predetermined control channel candidate.

The present invention discloses a method and device for receiving a downlink control channel according to various embodiments. A method and device are disclosed, the method for receiving a downlink control channel according to an aspect of the present invention includes: a step for receiving a subframe including a downlink control region; and a step for performing blind decoding on a search space in the downlink control region, wherein the search space includes a plurality of PDCCH candidates which correspond to respective aggregation levels and include control channel elements (CCEs), and each of the plurality of PDCCH candidates overlaps at least one PDCCH candidate.

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. Further, the UE may determine a limit of a number of serving cells based on the capability and a configuration of serving cells. The UE may determine a total limit of PDCCH candidates and non-overlapped control channel elements (CCEs) to monitor in a slot for a cell group and a per cell limit single TRP cells and for multiple TRP cells based on the limit of the number of serving cells. Alternatively, the limits may be defined per control resource set (CORESET) group.

Phase variations between a transmitter (TX) waveform and a receiver (RX) waveform produced by a TX Phase-Locked-Loop (PLL) and a RX PLL, respectively, is a source of error in processing delay calibration used, e.g., in Round Trip Time (RTT) estimation. While a TX waveform and a RX waveform have a constant phase delay while in steady state conditions, during transient times, e.g., at start up or reset, the phase delay may vary by as much as 180, which at baseband frequencies of 50 MHz, introduces a random delay variations of as much as 10 nsec, which is undesirable for fine position estimation using RTT. The phase delay variation between the TX waveform and RX waveform may be reduced or eliminated using a phase correction signal generated using the output signals of the TX PLL and RX PLL.

Phase variations between a transmitter (TX) waveform and a receiver (RX) waveform produced by a TX Phase-Locked-Loop (PLL) and a RX PLL, respectively, is a source of error in processing delay calibration used, e.g., in Round Trip Time (RTT) estimation. While a TX waveform and a RX waveform have a constant phase delay while in steady state conditions, during transient times, e.g., at start up or reset, the phase delay may vary by as much as 180, which at baseband frequencies of 50 MHz, introduces a random delay variations of as much as 10 nsec, which is undesirable for fine position estimation using RTT. The phase delay variation between the TX waveform and RX waveform may be reduced or eliminated using a phase correction signal generated using the output signals of the TX PLL and RX PLL.