Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive configuration information for a plurality of carriers, wherein a number of carriers, of the plurality of carriers, exceeds a threshold associated with a monitoring capability of the UE, wherein the monitoring capability is for span-based monitoring of the plurality of carriers, wherein a distribution of at least one of a plurality of non-overlapped control channel elements (CCEs) or a plurality of blind decodes satisfies a per-span capability of the UE, wherein the distribution is among a plurality of sets of carriers, and wherein each set of carriers of the plurality of sets of carriers is associated with a respective subcarrier spacing and a respective span configuration. The UE may receive communications on the plurality of carriers in accordance with the distribution. Numerous other aspects are described.

A method and device for timing alignment are disclosed. The method includes widening spectra of two signals for timing misalignment estimation; performing cross-correlation between the two spectrum-widened signals; and estimating the timing misalignment between the two signals according to a result of the cross-correlation. Therefore, an accurate time alignment result will be obtained with low complexity. Furthermore, it will be appropriate for all types of signals including separated multi-carrier signals.

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.

The present disclosure includes example downlink signal sending methods, downlink signal receiving methods, and devices. In one example method a transmit end device indicates position information of at least one of a first signal or a second signal in time domain based on a position relationship between the first signal and the second signal in at least one of frequency domain or time domain. The transmit end device can then send a frame including the first signal and the second signal. In embodiments of the present invention, position information of a synchronization signal in time domain can be indicated, and sending of a single-symbol synchronization signal is also supported.

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.

The present invention provides a signal sending apparatus, a signal detection apparatus, a signal sending and detection system, a signal sending method, and a signal detection method. The apparatus determines a time unit that is in each time window and that is used to transmit a synchronization signal, and transmits the synchronization signal in the determined time unit in each time window. Therefore, a synchronization signal is always located in a time unit that has a fixed location in each time window, so that a device at a receive end needs to perform detection only in a fixed time unit in each time window, thereby reducing complexity of designing and detecting the synchronization signal.

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.

Communication systems and methods in accordance with various embodiments of the invention utilize modulation on zeros. Carrier frequency offsets (CFO) can result in an unknown rotation of all zeros of a received signal's z-transform. Therefore, a binary MOCZ scheme (BMOCZ) can be utilized in which the modulated binary data is encoded using a cycling register code (e.g. CPC or ACPC), enabling receivers to determine cyclic shifts in the BMOCZ symbol resulting from a CFO. Receivers in accordance with several embodiments of the invention include decoders capable of decoding information bits from received discrete-time baseband signals by: estimating a timing offset for the received signal; determining a plurality of zeros of a z-transform of the received symbol; identifying zeros from the plurality of zeros that encode received bits by correcting fractional rotations resulting from the CFO; and decoding information bits based upon the received bits using a cycling register code.

The present invention concerns a system for the blind demodulation of a linearly modulated digital telecommunication signal and comprising modules allowing the estimation, monitoring of the temporal variations and corrections in the value of the phases, amplitudes, frequencies, time offsets and a set of compensation filters of the propagation channel, characterized in that it comprises at least one hardware or hardware and firmware architecture comprising memories and one or more processing units for implementing a network of specific calculation blocks connected to each other, including a block for the blind synchronization of the signal allowing the estimation, monitoring and compensation of the delay of the signal and also making it possible to adapt the processing rate of the downstream chain (of the demodulation system) to the reduced cadence of one sample per symbol, a first block incorporates at least one module making it possible to estimate at least one of the parameters of the observed signals in order to subsequently evaluate the other parameters of the observed signals, by other calculation blocks of the network, at least a second specialized calculation block incorporates a decision module in order to calculate an error signal and retro-propagate the calculated errors to each of the preceding residual blocks.

Methods, systems, and devices for wireless communications are described that provide for multiple-input multiple-output (MIMO) transmissions of control information using downlink control channel resources, such as physical downlink control channel (PDCCH) resources. The MIMO transmissions may provide control channel transmissions to multiple UEs using the same time-frequency resources. A base station may use a subset of control channel monitoring entities for MIMO control channel transmissions, and another subset of control channel monitoring candidates for non-MIMO control channel transmissions. Control channel monitoring entities for MIMO transmissions may be defined separately from non-MIMO or legacy control channel candidates.