Patent Description:
<CIT> is directed to PDCCH search space design for LTE-A multi-carrier operation.

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for conveying command or allocation information for multiple component carriers (CCs).

For example, base station <NUM> may send DCI with command or allocation information for multiple component carriers (CCs) to configure one or more UEs <NUM> to communicate in the multiple CCs.

The wireless communication network <NUM> may be a New Radio (NR) or <NUM> network. As illustrated in <FIG>, the wireless network <NUM> may include a number of base stations (BSs) <NUM> and other network entities. A BS may be a station that communicates with user equipments (UEs). Each BS <NUM> may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to a coverage area of a Node B (NB) and/or a Node B subsystem serving this coverage area, depending on the context in which the term is used. In NR systems, the term "cell" and next generation NodeB (gNB), new radio base station (NR BS), <NUM> NB, access point (AP), or transmission reception point (TRP) may be interchangeable. In some examples, the base stations may be interconnected to one another and/or to one or more other base stations or network nodes (not shown) in wireless communication network <NUM> through various types of backhaul interfaces, such as a direct physical connection, a wireless connection, a virtual network, or the like using any suitable transport network.

<FIG> illustrates example components of BS <NUM> and UE <NUM> (as depicted in <FIG>), which may be used to implement aspects of the present disclosure. For example, antennas <NUM>, processors <NUM>, <NUM>, <NUM>, and/or controller/processor <NUM> of the UE <NUM> and/or antennas <NUM>, processors <NUM>, <NUM>, <NUM>, and/or controller/processor <NUM> of the BS <NUM> may be used to perform the various techniques and methods described herein.

The SS block may be transmitted up to sixty-four times, for example, with up to sixty-four different beam directions for mmW.

A control resource set (CORESET) for an OFDMA system (e.g., a communications system transmitting PDCCH using OFDMA waveforms) may comprise one or more control resource (e.g., time and frequency resources) sets, configured for conveying PDCCH, within the system bandwidth. Within each CORESET, one or more search spaces (e.g., common search space (CSS), UE-specific search space (USS), etc.) may be defined for a given UE. According to aspects of the present disclosure, a CORESET is a set of time and frequency domain resources, defined in units of resource element groups (REGs). Each REG may comprise a fixed number (e.g., twelve) tones in one symbol period (e.g., a symbol period of a slot), where one tone in one symbol period is referred to as a resource element (RE). A fixed number of REGs may be included in a control channel element (CCE). Sets of CCEs may be used to transmit new radio PDCCHs (NR-PDCCHs), with different numbers of CCEs in the sets used to transmit NR-PDCCHs using differing aggregation levels. Multiple sets of CCEs may be defined as search spaces for UEs, and thus a NodeB or other base station may transmit an NR-PDCCH to a UE by transmitting the NR-PDCCH in a set of CCEs that is defined as a decoding candidate within a search space for the UE, and the UE may receive the NR-PDCCH by searching in search spaces for the UE and decoding the NR-PDCCH transmitted by the NodeB.

Aspects of the present disclosure provide techniques for conveying command and/or allocation information for multiple component carriers (CCs). For example, a network entity (e.g., a gNB) may send a downlink control information (DCI) to schedule transmissions and/or activate search spaces for multiple component carriers (CCs). In some cases, the DCI may carry a command for power adaptation in one or more of the multiple CCS (e.g., a command for the UE to adjust transmission power for transmission from the UE in one or more of the multiple CCs).

In some cases, it may be beneficial to dynamically control what search spaces a UE monitors. For example, for a UE's power saving operation, a BS may dynamically change and indicate the number of search space sets which the UE should monitor for control channel (PDCCH) decoding. Because control channel monitoring is associated with a number of blind decoding, reducing the number of CCs for control channel monitoring can save UE's baseband processing power.

<FIG> illustrates an example of dynamic search space control, in accordance with certain aspects of the present disclosure. In the illustrated example, a primary component carrier (PCC) may contain an anchor search space set, while a secondary component carrier (SCC) contains a non-anchor search space set. In some cases, the Scell search space set may be activated via a MAC-CE, but initially the SCell only contains an inactive search space set.

Rather than activation via a MAC-CE, DCI signaling may be preferred as a method of delivering a search space set activation command due to short latency. Aspects of the present disclosure provide a DCI with a format that may allow for command or allocation information, for example, to convey multi-carrier scheduling and search space activation.

<FIG> illustrates example operations <NUM> for wireless communications by a UE, in accordance with aspects of the present disclosoure. Operations <NUM> may be performed, for example, by a UE <NUM> of <FIG> to receive in process DCI from a base station conveying command or allocation information for communicating in multiple CCs.

According to aspects, the UE may include one or more components as illustrated in <FIG> which may be configured to perform the operations described herein. For example, the antenna <NUM>, demodulator/modulator <NUM>, controller/processor <NUM>, and/or memory <NUM> as illustrated in <FIG> may perform the operations <NUM> of <FIG>.

Operations <NUM> begin at <NUM> by receiving a downlink control information (DCI) having one or more fields for activating search spaces in multiple component carriers (CCs). At <NUM>, the UE monitors the search spaces in the multiple CCs for control channel transmissions.

<FIG> illustrates example operations <NUM> for wireless communications by a network entity (e.g., a base station/gNB), in accordance with aspects of the present disclosoure. Operations <NUM> may be performed, for example, by a base station <NUM> of <FIG> to configure a UE <NUM> for communicating in multiple CCs.

According to aspects, the BS may include one or more components as illustrated in <FIG> which may be configured to perform the operations described herein. For example, the antenna <NUM>, demodulator/modulator <NUM>, controller/processor <NUM>, and/or memory <NUM> as illustrated in <FIG> may perform the operations <NUM> of <FIG>.

Operations <NUM> begin at <NUM> by generating a downlink control information (DCI) having one or more fields to convey command or allocation information for multiple component carriers (CCs). At <NUM>, the network entity transmits the DCI to a user equipment (UE) to configure the UE to communicate in the multiple CCs in accordance with the command or allocation information.

As noted above, a BS may transmit a DCI for multi-carrier scheduling, search space activation, and/or adaptation of transmit power in one of the corresponding multiple carriers. For example, <FIG> illustrates an example DCI format that may be defined for delivering commands and/or allocation information for multiple cells (carriers) simultaneously. Based on a configuration (e.g., sent via RRC signaling), the DCI format may be associated with a set of cells.

As illustrated in <FIG>, the type of DCI used to convey the commands and/or allocation information (e.g., for multi-carrier scheduling, search space activation and/or adaptation of transmit power in one of the corresponding multiple carriers) may contain one or more common information fields and one or more dedicated information fields. The common information fields may carry information that applies to all associated cells. The dedicated information fields may carry information that applies only to a corresponding cell (e.g., each dedicated information field may be mapped to a corresponding cell).

The DCI may be used to deliver SS set activation (and/or transmit power) commands for other cells. For example, the proposed DCI may be transmitted within the anchor search space. The dedicated information fields may contain activation (or de-activation) commands/states for SS sets in other cells. In addition, or as an alternative, the common information fields may contain activation (or de-activation) commands/states for all search space sets in other cells.

There may be various types of activation use cases, which may or may not also involve same carrier (self-scheduling referring to scheduling in a same carrier in which the DCI is sent) or cross-carrier scheduling (referring to scheduling in a carrier different from the carrier in which the DCI is sent).

<FIG> illustrates one example option for search space set activation commands only. As illustrated, a DCI sent in a primary CC (CC0) activates search spaces in multiple CCs (e.g., CC1-CC7). In this example, the DCI is used only for SS set activation, with no scheduling grant for DL/UL data is included in the DCI.

After receiving this type of DCI, UE may send feedback to the BS for confirmation. After a SS set in a cell is activated, that search space may be used to convey PDCCH for scheduling DL/UL data in the same cell.

<FIG> illustrates another example option for search space set activation commands and self-scheduling. As in <FIG>, a DCI sent in CC0 activates search spaces in multiple CCs. In this example, however, the DCI is used for both search space set activation and scheduling DL/UL data. In this example, the scheduling is referred to as self-scheduling since the DL/UL data is scheduled in the same cell that the DCI is transmitted. In this case, HARQ feedback for the scheduled data may be considered as confirmation from UE for receiving the search space set activation command.

<FIG> illustrates another example for search space set activation commands and multi-cell scheduling. As illustrated, in this case, DCI is used for SS set activation and scheduling DL/UL data in all cells for which the DCI activates SS.

In some cases, the scheduling grant may be identical for all cells (and possibly carried in a common information field). On the other hand, the scheduling grant may be different for all cells (and these grants may be carried in corresponding dedicated information fields). In this case, HARQ feedback for the scheduled data may be considered as confirmation from the UE for receiving the search space set activation command.

As illustrated in <FIG>, a DCI may also be used for search space set de-activation. For de-activation, similar DCI types and options as described above with reference to <FIG> may be used. As illustrated, the DCI may deactivate SS in CC1-CC7, while scheduling DL/UL data in CC0.

For example, instructions for performing the operations described herein and illustrated in <FIG> and <FIG>.

Claim 1:
A method of wireless communications by a user equipment, UE (<NUM>) in a New Radio, NR, network (<NUM>), comprising:
receiving (<NUM>) a downlink control information, DCI having one or more fields to convey command or allocation information for multiple component carriers, CCs; and
taking (<NUM>) at least one action with regard to the multiple CCs in accordance with the command or allocation information, wherein:
the one or more fields convey a command to activate search spaces in the multiple CCs; and
taking the action comprises monitoring the search spaces in the multiple CCs for control channel information and wherein the DCI comprises:
one or more common information fields for carrying information that applies to each of the multiple CCs; and
one or more dedicated information fields for carrying information that applies only to a corresponding one of the CCs.