Patent Description:
The present disclosure relates generally to communication systems, and in particular, to techniques of determining a control resource set (CORESET) resource allocation and Demodulation Reference Signal (DMRS) mapping in the CORESET. More particularly, the present invention relates to a method according to the pre-characterizing part of independent claim <NUM> and a corresponding apparatus according to the pre-characterizing part of independent claim <NUM>. Such method and apparatus are disclosed in document <NPL>".

Document <NPL>" discloses that the starting position of a bandwidth part (BWP) could be in any physical resource block (PRB) within the maximum bandwidth supported in radio access network <NUM> (RANI).

The above-mentioned objectives are achieved by a method according to independent claim <NUM> and a corresponding apparatus according to independent claim <NUM>.

The dependent claims define preferred embodiments thereof.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The UE receives a CORESET configuration of a first CORESET, the CORESET configuration indicating a reference location of the first CORESET with reference to a reference point in a frequency domain. The UE further determines resources occupied by the first CORESET in the frequency domain of a carrier based on the reference location and the reference point. The UE performs blind decoding on DCCH resource candidates in a search space carried by the first CORESET to obtain a down-link control channel.

In another aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The UE determines a first down link control channel (DCCH) resource candidate in a first control resource set (CORESET) on a carrier, the first DCCH resource candidate including a first set of resource blocks (RBs). The UE also determines a first sequence of DMRSs that are mapped, starting at a reference point, to resource blocks (RBs) in a predetermined range within the carrier in a frequency domain, the predetermined range containing the first DCCH resource candidate in the frequency domain. The UE further determines, with reference to the reference point in the frequency domain, a first reference location of the first set of RBs. The UE determines, based on the first reference location, a first set of DMRSs from the first sequence of DMRSs, the first set of DMRSs being mapped to the first set of RBs. The UE obtains a channel estimation based on the first set of DMRSs; and The UE performs blind decoding of the first DCCH resource candidate based on the channel estimation.

By way of example, and not limitation, such computer- readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

The base stations <NUM> (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E- UTRAN)) interface with the EPC <NUM> through backhaul links <NUM> (e.g., S1 interface).

There may be overlapping geographic coverage areas <NUM><NUM>. For example, the small cell <NUM>' may have a coverage area <NUM>' that overlaps the coverage area <NUM><NUM> of one or more macro base stations <NUM>. A network that includes both small cell and macro cells may be known as a heterogeneous network. The base stations <NUM> / UEs <NUM> may use spectrum up to Y MHz (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL).

The IP Services <NUM> may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service (PSS), and/or other IP services.

The base station may also be referred to as a gNB, Node B, evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. The base station <NUM> provides an access point to the EPC <NUM> for a UE <NUM>. Examples of UEs <NUM> include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a toaster, or any other similar functioning device. Some of the UEs <NUM> may be referred to as loT devices (e.g., parking meter, gas pump, toaster, vehicles, etc.).

Each spatial stream may then be provided to a different antenna <NUM> via a separate transmitter 218TX. Each transmitter 218TX may modulate an RF carrier with a respective spatial stream for transmission.

At the UE <NUM>, each receiver 254RX receives a signal through its respective antenna <NUM>. Each receiver 254RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor <NUM>.

The memory <NUM> may be referred to as a computer- readable medium.

The spatial streams generated by the TX processor <NUM> may be provided to different antenna <NUM> via separate transmitters 254TX. Each transmitter 254TX may modulate an RF carrier with a respective spatial stream for transmission. Each receiver 218RX receives a signal through its respective antenna <NUM>. Each receiver 218RX recovers information modulated onto an RF carrier and provides the information to a RX processor <NUM>.

The memory <NUM> may be referred to as a computer- readable medium.

NR may utilize OFDM with a cyclic prefix (CP) on the uplink and downlink and may include support for half-duplex operation using time division duplexing (TDD). NR may include Enhanced Mobile Broadband (eMBB) service targeting wide bandwidth (e.g. <NUM> beyond), millimeter wave (mmW) targeting high carrier frequency (e.g. <NUM>), massive MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low latency communications (URLLC) service.

A single component carrier bandwidth of <NUM> may be supported. In one example, NR resource blocks (RBs) may span <NUM> sub-carriers with a sub-carrier bandwidth of <NUM> over a <NUM> duration or a bandwidth of <NUM> over a <NUM> duration. Each radio frame may consist of <NUM> or <NUM> subframes (or NR slots) with a length of <NUM>. Each subframe may indicate a link direction (i.e., DL or UL) for data transmission and the link direction for each subframe may be dynamically switched. Each subframe may include DL/UL data as well as DL/UL control data. UL and DL subframes for NR may be as described in more detail below with respect to <FIG> and <FIG>.

The NR RAN may include a central unit (CU) and distributed units (DUs). A NR BS (e.g., gNB, <NUM> Node B, Node B, transmission reception point (TRP), access point (AP)) may correspond to one or multiple BSs. NR cells can be configured as access cells (ACells) or data only cells (DCells). For example, the RAN (e.g., a central unit or distributed unit) can configure the cells. DCells may be cells used for carrier aggregation or dual connectivity and may not be used for initial access, cell selection/reselection, or handover. In some cases DCells may not transmit synchronization signals (SS) in some cases DCells may transmit SS. NR BSs may transmit downlink signals to UEs indicating the cell type. Based on the cell type indication, the UE may communicate with the NR BS. For example, the UE may determine NR BSs to consider for cell selection, access, handover, and/or measurement based on the indicated cell type.

<FIG> illustrates an example logical architecture <NUM> of a distributed RAN, according to aspects of the present disclosure. The backhaul interface to the next generation core network (NG- CN) <NUM> may terminate at the ANC.

The local architecture of the distributed RAN <NUM> may be used to illustrate fronthaul definition.

According to aspects, a dynamic configuration of split logical functions may be present within the architecture of the distributed RAN <NUM>. The PDCP, RLC, MAC protocol may be adaptably placed at the ANC or TRP.

The C- RU may have distributed deployment.

The DL-centric subframe may also include a common UL portion <NUM>. The common UL portion <NUM> may sometimes be referred to as an UL burst, a common UL burst, and/or various other suitable terms. The common UL portion <NUM> may include feedback information corresponding to various other portions of the DL-centric subframe. For example, the common UL portion <NUM> may include feedback information corresponding to the control portion <NUM>. Non-limiting examples of feedback information may include an ACK signal, a NACK signal, a HARQ indicator, and/or various other suitable types of information. The common UL portion <NUM> may include additional or alternative information, such as information pertaining to random access channel (RACH) procedures, scheduling requests (SRs), and various other suitable types of information.

As illustrated in <FIG>, the end of the DL data portion <NUM> may be separated in time from the beginning of the common UL portion <NUM>. One of ordinary skill in the art will understand that the foregoing is merely one example of a DL-centric subframe and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

<FIG> is a diagram <NUM> showing an example of an UL-centric subframe. The UL-centric subframe may include a control portion <NUM>. The control portion <NUM> may exist in the initial or beginning portion of the UL-centric subframe. The control portion <NUM> in <FIG> may be similar to the control portion <NUM> described above with reference to <FIG>. The UL-centric subframe may also include an UL data portion <NUM>. The UL data portion <NUM> may sometimes be referred to as the pay load of the UL-centric subframe. The UL portion may refer to the communication resources utilized to communicate UL data from the subordinate entity (e.g., UE) to the scheduling entity (e.g., UE or BS). In some configurations, the control portion <NUM> may be a physical DL control channel (PDCCH).

As illustrated in <FIG>, the end of the control portion <NUM> may be separated in time from the beginning of the UL data portion <NUM>. The UL-centric subframe may also include a common UL portion <NUM>. The common UL portion <NUM> in <FIG> may be similar to the common UL portion <NUM> described above with reference to <FIG>. The common UL portion <NUM> may additionally or alternatively include information pertaining to channel quality indicator (CQI), sounding reference signals (SRSs), and various other suitable types of information. One of ordinary skill in the art will understand that the foregoing is merely one example of an UL-centric subframe and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

Channel state information (CSI) reports provide the network with information about the current channel conditions. CSI usually comprises one or more pieces of information: rank indicator (RI), precoder matrix indicator (PMI), channel-quality indicator (CQI), and channel state information reference signal (CSI-RS) resource indicator (CRI).

<FIG> is a diagram <NUM> illustrating communications between a base station <NUM> and UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G and a first technique for CORESET resource allocation. In particular, the base station <NUM> communicates with the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G on a carrier <NUM> in a slot <NUM>. The base station <NUM> may further assign a bandwidth part on the carrier <NUM> to each of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. A bandwidth part may occupy a smaller portion of or all of the bandwidth of the carrier <NUM>. A UE communicates with the base station <NUM> using frequencies within the bandwidth of the assigned bandwidth part. In this example, the UE <NUM>-<NUM> communicates on a bandwidth part <NUM>-<NUM> and the UE <NUM>-<NUM> communicates on a bandwidth part <NUM>-<NUM> with the base station <NUM>.

Further, the base station <NUM> may assign one or more CORESETs in the slot <NUM> to one or more of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. Each CORESET may be a common CORESET and, optionally, an additional CORESET in the control region <NUM>. A common CORESET contains a common search space (CSS) and a UE-specific search space (USS). A CSS is to be accessed by one or more groups of UEs. The base station <NUM> can signal properties of a common CORESET to the UE <NUM>-<NUM> via master information block (MIB) carried by PBCH. The CSS and the USS can be fully or partially overlapped in frequency and time domains for better resource utilization. The base station <NUM> may not configure all of the properties of a common CORESET described infra via MIB if signaling overhead reduction is needed. Some properties, e.g., REG-to-CCE mapping, search space configurations, can be predefined and, therefore, do not need to be signaled. In addition to the USS, the UE-specific DCI can also be transmitted in the CSS of the common CORESET if there are unused resources in the CSS.

An additional CORESET contains either (a) a CSS and a USS or (b) one or more USSes only. The UE <NUM>-<NUM> can be configured to monitor one or more additional CORESETs via RRC signaling after C-RNTI is available. An additional CORESET can have one or more USSes. The base station <NUM> can configure an additional CORESET for cross-carrier scheduling in carrier scheduling with the UE <NUM>-<NUM>. When the UE <NUM>-<NUM> is configured with more than one beam pair link, the UE <NUM>-<NUM> may receive PDCCHs corresponding to different analog beams in an additional CORESET.

In this example, the base station <NUM> assigns a CORESET <NUM> to the UE <NUM>-<NUM> and a CORESET <NUM> to the UE <NUM>-<NUM>.

As described infra, a CORESET may be defined by multiple properties. The base station <NUM> can send a CORESET configuration to each of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. The CORESET configuration specifies one or more properties of a CORESET (e.g., the CORESET <NUM> or the CORESET <NUM>). As described supra, the base station <NUM> signals the CORESET configuration specifying the properties of a common CORESET via MIB and/or a control message such as an RRC message.

In one example, the base station <NUM> signals a CORESET configuration specifying properties of the CORESET <NUM> to the UE <NUM>-<NUM>. In particular, the CORESET configuration may indicate resources allocated to the CORESET <NUM> on the carrier <NUM> in the frequency domain and/or the time domain.

In this example, the CORESET <NUM> occupies one symbol period or a set of contiguous OFDM symbol periods in time domain. The CORESET configuration can indicate the starting symbol period and time duration to specify the time resource allocation of the CORESET <NUM>.

As described infra, the base station <NUM> may employ several techniques to indicate frequency domain resource allocation in the CORESET configuration. In a first technique, the base station <NUM> indicates frequencies of the CORESET <NUM> based on the actual resource block (RB) indexing of the carrier <NUM>. In a symbol period <NUM>, there are NRBMAX RBs spanning across the carrier <NUM>. Each RB contains <NUM> subcarriers in a single symbol period. The NRBMAX RBs are indexed from <NUM> to (NRBMAX- <NUM>) from the lower boundary of the frequency of the carrier <NUM>. Further, the base station <NUM> allocates the frequency resources by an allocation unit that contains <NUM> RBs. Therefore, there are floor(NRBMAX/<NUM>), which is the largest integer that is not greater than NRBMAX/<NUM>, allocation units spanning across the carrier <NUM> in the symbol period <NUM>. In one configuration, in the CORESET configuration of the CORESET <NUM>, the base station <NUM> may use a bitmap having floor(NRBMAX/<NUM>) bits to indicate whether each of the floor(NRBMAX/<NUM>) allocation units is a part of the CORESET <NUM>. In this example, in the bitmap, bits corresponding to allocation unit <NUM> to allocation unit <NUM> as well as bits corresponding to allocation unit <NUM> to allocation unit <NUM> each have a value <NUM>, as those allocation units are not parts of the CORESET <NUM>. Bits corresponding to allocation unit <NUM> to allocation unit <NUM> each have a value <NUM>, as those allocation units are a part of the CORESET <NUM>.

As described supra, the base station <NUM> assigns the CORESET <NUM> to the UE <NUM>-<NUM>. Accordingly, the base station <NUM> sends a CORESET configuration to the UE <NUM>-<NUM> with a bitmap having a bit corresponding to each allocation unit within the allocation unit <NUM> to allocation unit <NUM>. The bits in the bitmap corresponding to the allocation unit <NUM> to allocation unit <NUM> each have a value of <NUM>, while the other bits in the bitmap each have a value of <NUM>.

In another configuration, instead of using a bitmap, the base station <NUM> may use the RB with an index <NUM> as a reference point, and may indicate a reference location of a lower boundary in the frequency domain of the CORESET <NUM>. The reference location is indicated by the number of allocation units away from the reference point. In this example, the reference location of the CORESET <NUM> is <NUM>, as the reference location is <NUM> allocation units away from the reference point. In CORESET configuration may also indicates bandwidth of the CORESET <NUM> by the number of allocation units assigned to the CORESET <NUM>.

When one or more of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G and the base station <NUM> employs this technique on the carrier <NUM>, those UEs have the same RB grid, which is indexed from <NUM> to (NRBMAX- <NUM>).

By employing the first technique, each of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G can determine one or more CORESETs assigned that UE. Subsequently, the UE can perform blind decoding on DCCH resource candidates in a search space carried by a CORESET to obtain a down-link control channel.

<FIG> is a diagram <NUM> illustrating communications between a base station <NUM> and UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G and a second technique for CORESET resource allocation. In particular, the base station <NUM> communicates with the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G on a carrier <NUM> in a slot <NUM>. The base station <NUM> may further assign a bandwidth part on the carrier <NUM> to each of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. A bandwidth part may occupy a smaller portion of or all of the bandwidth of the carrier <NUM>. A UE communicates with the base station <NUM> using frequencies within the bandwidth of the assigned bandwidth part. In this example, the UE <NUM>-<NUM> communicates on a bandwidth part <NUM>-<NUM> and the UE <NUM>-<NUM> communicates on a bandwidth part <NUM>-<NUM> with the base station <NUM>.

Further, the base station <NUM> may assign one or more CORESETs in the slot <NUM> to one or more of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. In this example, the base station <NUM> assigns a CORESET <NUM> to the UE <NUM>-<NUM> and a CORESET <NUM> to the UE <NUM>-<NUM>.

As described infra, a CORESET may be defined by multiple properties. The base station <NUM> can send a CORESET configuration to each of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. The CORESET configuration specifies one or more properties of a CORESET (e.g., the CORESET <NUM> or the CORESET <NUM>).

In a second technique, the base station <NUM> signals a CORESET configuration specifying properties of the CORESET <NUM> to the UE <NUM>-<NUM>. In particular, the CORESET configuration may indicate resources allocated to the CORESET <NUM> on the carrier <NUM> in the frequency domain and/or the time domain.

As described supra, the base station <NUM> may employ several techniques to indicate frequency domain resource allocation in the CORESET configuration. In this second technique, the base station <NUM> indicates frequencies of a CORESET assigned to the UE <NUM>-<NUM> (i.e., the CORESET <NUM>) based on the RB indexing of the bandwidth part assigned to the UE <NUM>-<NUM> (i.e., the bandwidth part <NUM>-<NUM>).

More specifically, in a symbol period <NUM>, there are NRBBWP<NUM>,MAX RBs spanning across the bandwidth part <NUM>-<NUM>. The NRBBWP<NUM>,MAX RBs are indexed from <NUM> to (NRBBWP<NUM>,MAX- <NUM>) from the lower boundary of the frequency of the bandwidth part <NUM>-<NUM>. Therefore, there are floor(NRBBWP<NUM>,MAX/<NUM>), which is the largest integer that is not greater than NRBBWP<NUM>,MAX/<NUM>, allocation units spanning across the bandwidth part <NUM>-<NUM> in the symbol period <NUM>. The RB with index <NUM> is a reference point. In one configuration, in the CORESET configuration of the CORESET <NUM>, the base station <NUM> may use a bitmap having floor(NRBBWP<NUM>,MAX/<NUM>) bits to indicate whether each of the floor(NRBBWP<NUM>,MAX/<NUM>) allocation units is a part of the CORESET <NUM>. In this example, in the bitmap, bits corresponding to allocation unit <NUM> to allocation unit <NUM> as well as bits corresponding to allocation unit <NUM> to allocation unit <NUM> each have a value <NUM>, as those allocation units are not parts of the CORESET <NUM>. Bits corresponding to allocation unit <NUM> to allocation unit <NUM> each have a value <NUM>, as those allocation units are a part of the CORESET <NUM>.

Compared with the first technique, the second technique may have the benefit of lower signaling overhead for resource allocation configuration. By employing the second technique, each of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G can determine one or more CORESETs assigned that UE. Subsequently, the UE can perform blind decoding on DCCH resource candidates in a search space carried by a CORESET to obtain a down-link control channel.

<FIG> is a diagram <NUM> illustrating communications between a base station <NUM> and UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G and a third technique for CORESET resource allocation, which technique is the only one scope of protection of the attached set of claims. In particular, the base station <NUM> communicates with the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G on a carrier <NUM> in a slot <NUM>. Further, the UE <NUM>-<NUM> communicates on a bandwidth part <NUM>-<NUM> and the UE <NUM>-<NUM> communicates on a bandwidth part <NUM>-<NUM> with the base station <NUM>.

In a third technique, the base station <NUM> signals a CORESET configuration specifying properties of the CORESET <NUM> to the UE <NUM>-<NUM>. In particular, the CORESET configuration may indicate resources allocated to the CORESET <NUM> on the carrier <NUM> in the frequency domain and/or the time domain.

As described supra, the base station <NUM> may employ several techniques to indicate frequency domain resource allocation in the CORESET configuration. In this third technique, the base station <NUM> indicates frequencies of a CORESET assigned to the UE <NUM>-<NUM> (i.e., the CORESET <NUM>) based on the RB indexing of the bandwidth part assigned to the UE <NUM>-<NUM> (i.e., the bandwidth part <NUM>-<NUM>) with an offset.

More specifically, as shown in a symbol period <NUM>, there are NRBBWP<NUM>,MAX RBs spanning across the bandwidth part <NUM>-<NUM>. The NRBBWP<NUM>,MAX RBs are indexed from <NUM> to (NRBBWP<NUM>,MAX- <NUM>) from the lower boundary of the frequency of the bandwidth part <NUM>-<NUM>. Therefore, there are floor(NRBBWP<NUM>,MAX/<NUM>) allocation units spanning across the bandwidth part <NUM>-<NUM> in the symbol period <NUM> (and other symbol periods).

Further, with respect to the bandwidth part <NUM>-<NUM>, as shown in a symbol period <NUM>, there are NRBBWP<NUM>,MAX RBs spanning across the bandwidth part <NUM>-<NUM>. The NRBBWP<NUM>,MAX RBs are indexed from <NUM> to (NRBBWP<NUM>,MAX- <NUM>) from the lower boundary of the frequency of the bandwidth part <NUM>-<NUM>. Therefore, there are floor(NRBBWP<NUM>,MAX/<NUM>), which is the largest integer that is not greater thanNRBBWP<NUM>. MAX/<NUM>, allocation units spanning across the bandwidth part <NUM>-<NUM> in the symbol period <NUM> (and other symbol periods).

In accordance with the second technique, the base station <NUM> may assign allocation units for the CORESET <NUM> of the UE <NUM>-<NUM> starting from the RB with index <NUM> in the bandwidth part <NUM>-<NUM>. Therefore, an initial allocation unit <NUM>' contains RBs with indices <NUM>-<NUM> in the bandwidth part <NUM>-<NUM>. Similarly, the base station <NUM> may assign allocation units for the CORESET <NUM> of the UE <NUM>-<NUM> starting from the RB with index <NUM> in the bandwidth part <NUM>-<NUM>. Therefore, an initial allocation unit <NUM> contains RBs with indices <NUM>-<NUM> in the bandwidth part <NUM>-<NUM>. In this example, the RB with an index of <NUM> in the bandwidth part <NUM>-<NUM> has an index of <NUM> in the bandwidth part <NUM>-<NUM>.

In this example, in accordance with the second technique, the allocation units assigned in the bandwidth part <NUM>-<NUM> by the base station <NUM> is not assigned with the allocation units assigned in the bandwidth part <NUM>-<NUM>. That is, the boundaries of the allocation units in the bandwidth part <NUM>-<NUM> are not the same as the boundaries of the allocation units in the bandwidth part <NUM>-<NUM>. As such, an allocation unit <NUM>' of the CORESET <NUM> overlaps with both allocation unit <NUM> and allocation unit <NUM> of the CORESET <NUM>. In other words, transmission in RBs of one allocation unit of the CORESET <NUM> may block or interfere with transmission in RBs of two allocation units of the CORESET <NUM>.

In this third technique, the base station <NUM> determines an offset of the lower boundary of the bandwidth part <NUM>-<NUM> with the RB (i.e., the RB with index <NUM> on the carrier <NUM>) that is m allocation units of RBs away from lower boundary of the carrier <NUM> (i.e., the RB with index <NUM> on the carrier <NUM>). m is the smallest integer such that the index on the carrier <NUM> assigned to the RB with index <NUM> in the bandwidth part <NUM>-<NUM> is 6mor is smaller than <NUM>. The offset may be from <NUM> RB to <NUM> RBs. In this example, the RB with index <NUM> in the bandwidth part <NUM>-<NUM> has an index (<NUM>-<NUM>) on the carrier <NUM>. Therefore, the offset associated with the bandwidth part <NUM>-<NUM> is <NUM> RBs. The base station <NUM> adds the offset to the index of the starting RB of an initial allocation unit <NUM> of the bandwidth part <NUM>-<NUM>. That is, according to the third technique, in this example, the initial allocation unit <NUM> starts at the RB with an index of <NUM>, comparing to starting at the RB with an index of <NUM> in accordance with the second technique; the base station <NUM> assigns allocation units for RBs with indices <NUM> to NRBBWP<NUM>,MAX.

Similarly, the base station <NUM> determines an offset of the lower boundary of the bandwidth part <NUM>-<NUM> with the RB with an index <NUM>j on the carrier <NUM>. j is the smallest integer such that the index on the carrier <NUM> assigned to the RB with index <NUM> in the bandwidth part <NUM>-<NUM> is 6j or smaller than 6j, In this example, the RB with index <NUM> in the bandwidth part <NUM>-<NUM> has an index 6jon the carrier <NUM>. Therefore, the offset associated with the bandwidth part <NUM>-<NUM> is <NUM> RB. Accordingly, the base station <NUM> assigns allocation unitsin the bandwidth part <NUM>-<NUM> in accordance with the second technique.

As such, the allocation units assigned in the bandwidth part <NUM>-<NUM> are aligned with the allocation units assigned in the bandwidth part <NUM>-<NUM>.

In one configuration, in the CORESET configuration of the CORESET <NUM>, the base station <NUM> may use a bitmap having floor((NRBBWP<NUM>,MAX- offset)/<NUM>) bits to indicate whether each of the floor((NRBBWP<NUM>,MAX-offset)/<NUM>) allocation units is a part of the CORESET <NUM>. In this example, in the bitmap, bits corresponding to allocation unit <NUM> to allocation unit <NUM> as well as bits corresponding to allocation unit <NUM> to allocation unit <NUM> each have a value <NUM>, as those allocation units are not parts of the CORESET <NUM>. Bits corresponding to allocation unit <NUM> to allocation unit <NUM> each have a value <NUM>, as those allocation units are a part of the CORESET <NUM>.

As described supra, the granularities for a bandwidth parts and a CORESETs are <NUM> RB and <NUM> RBs, respectively. The bandwidth part <NUM>-<NUM> and the bandwidth part <NUM>-<NUM> are allocated in the same carrier <NUM> and configured to the UE <NUM>-<NUM> and the UE <NUM>-<NUM>, respectively. The bandwidth part <NUM>-<NUM> and the bandwidth part <NUM>-<NUM> are partially overlapped and the CORESET <NUM> and the CORESET <NUM> are partially overlapped in physical resources as well.

In the second technique, the frequency bandwidth and the starting RB of a bandwidth part in a carrier is not restricted. Therefore, the RB grids with allocation units of CORESETs in different bandwidth parts may not be aligned. As such, a PDCCH candidate in one CORESET may block more than one PDCCH candidates in the other CORESET, if their search spaces are partially overlapped.

Employing the third technique may reduce the blocking rate. An offset with granularity <NUM> RB can be applied to determine the starting RB indexing of the CORESETs such that the allocation units of different CORESETs are aligned. The offset can be signaled to UE through the higher-layer signaling with the resource allocation of CORESET.

By employing the third technique, each of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G can determine one or more CORESETs assigned that UE. Subsequently, the UE can perform blind decoding on DCCH resource candidates in a search space carried by a CORESET to obtain a down-link control channel.

<FIG> is a diagram <NUM> illustrating communications between a base station <NUM> and UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G and first and second options for DMRS mapping. In particular, the base station <NUM> communicates with the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G on a carrier <NUM> in a slot <NUM>. Further, the UE <NUM>-<NUM> communicates on a bandwidth part <NUM>-<NUM> and the UE <NUM>-<NUM> communicates on a bandwidth part <NUM>-<NUM> with the base station <NUM>.

Further, the base station <NUM> may assign one or more CORESETs in the slot <NUM> to one or more of the UEs <NUM>-<NUM>, <NUM>-<NUM>,. In this example, the base station <NUM> assigns a CORESET <NUM> and a CORESET <NUM> to the UE <NUM>-<NUM>.

The base station <NUM> signals a CORESET configuration specifying properties of the CORESET <NUM> to the UE <NUM>-<NUM>. In particular, the CORESET configuration may indicate resources allocated to the CORESET <NUM> on the carrier <NUM> in the frequency domain and/or the time domain.

After determines the resource allocation of the CORESET <NUM>, the UE <NUM>-<NUM> further determines a DMRS mapping in the CORESET <NUM>. In this first option, the base station <NUM> and the UE <NUM>-<NUM> agrees to use a reference point that is specific and relevant to the CORESET <NUM> to map a DMRS sequence <NUM>. Within a symbol period <NUM>, the CORESET <NUM> ranges in frequency domain from an RB <NUM> having the lowest frequency to an RB <NUM> having the highest frequency. In one example, the reference point is the RB <NUM>. Further, an RB contains <NUM> resource elements indexed from <NUM> to <NUM> on <NUM> subcarriers in a symbol period. In this example, resource elements with indices <NUM>, <NUM>, and <NUM> in each RB of a DCCH resource candidate are mapped with DMRSs.

In this option, the base station <NUM> generates the DMRS sequence <NUM> that can be mapped from the RB <NUM> to the RB <NUM>. But only if an RB in the CORESET is actually a part of a DCCH resource candidate, that RB will actually carry a DMRS from the sequence mapped to that RB.

In this example, the base station <NUM> configures a PDCCH resource candidate <NUM> including the RBs <NUM>, <NUM>, <NUM> in a symbol period <NUM>. On the other hand, the RB <NUM> is not a part of any DCCH resource candidate. Therefore, although the base station <NUM> generates the DMRS sequence <NUM> whose initial <NUM> DMRSs are mapped to the RB <NUM>, the base station <NUM> does not actually use the resource elements with indices <NUM>, <NUM>, and <NUM> in the RB <NUM> to carry those <NUM> DMRSs. The DMRS sequence <NUM> also contains <NUM> DMRSs mapped to the RBs <NUM>, <NUM>, <NUM>. As the RBs <NUM>, <NUM>, <NUM> are a part of the PDCCH resource candidate <NUM>, the base station <NUM> actually use the resource elements with indices <NUM>, <NUM>, and <NUM> in the RBs <NUM>, <NUM>, <NUM> to carry those <NUM> DMRSs.

Further, the base station <NUM> configures a PDCCH resource candidate <NUM> including the RBs <NUM>, <NUM>, <NUM> in a symbol period <NUM>. On the other hand, the RB <NUM> is not a part of any DCCH resource candidate. Therefore, although the base station <NUM> generates the DMRS sequence <NUM> whose initial <NUM> DMRSs are mapped to the RB <NUM>, the base station <NUM> does not actually use the resource elements with indices <NUM>, <NUM>, and <NUM> in the RB <NUM> to carry those <NUM> DMRSs. The DMRS sequence <NUM> also contains <NUM> DMRSs mapped to the RBs <NUM>, <NUM>, <NUM>. As the RBs <NUM>, <NUM>, <NUM> are a part of the PDCCH resource candidate <NUM>, the base station <NUM> actually use the resource elements with indices <NUM>, <NUM>, and <NUM> in the RBs <NUM>, <NUM>, <NUM> to carry those <NUM> DMRSs.

Correspondingly, after determining the resources of the CORESET <NUM>, the UE <NUM>-<NUM> generates the DMRS sequence <NUM> that can be mapped from the RB <NUM> to the RB <NUM>. The UE <NUM>-<NUM> further determines the RBs <NUM>, <NUM>, <NUM> in the symbol period <NUM> are a part of the PDCCH resource candidate <NUM>. Accordingly, the UE <NUM>-<NUM> measures the signals carried by the resource elements with indices <NUM>, <NUM>, and <NUM> in the RBs <NUM>, <NUM>, <NUM>. The UE <NUM>-<NUM> further performs a channel estimation based on the measured signals in those resource elements and the <NUM> DMRSs from the DMRS sequence <NUM> mapped to those resource elements.

Similarly, the base station <NUM> and the UE <NUM>-<NUM> agrees to use a reference point that is specific and relevant to the CORESET <NUM> to map a DMRS sequence <NUM>. Within a symbol period <NUM>, the CORESET <NUM> ranges in frequency domain from an RB <NUM> having the lowest frequency to an RB <NUM> having the highest frequency. In one example, the reference point is the RB <NUM>.

In this example, the base station <NUM> configures a PDCCH resource candidate <NUM> of the CORESET <NUM> including the RBs <NUM>, <NUM> in the symbol period <NUM>. Accordingly, the base station <NUM> use the resource elements with indices <NUM>, <NUM>, and <NUM> in the RBs <NUM>, <NUM> to carry those <NUM> DMRSs in the DMRS sequence <NUM> mapped to those RBs.

Correspondingly, after determining the resources of the CORESET <NUM>, the UE <NUM>-<NUM> generates the DMRS sequence <NUM> that can be mapped from the RB <NUM> to the RB <NUM>. The UE <NUM>-<NUM> further determines the RBs <NUM>, <NUM> in the symbol period <NUM> are a part of the PDCCH resource candidate <NUM>. Accordingly, the UE <NUM>-<NUM> measures the signals carried by the resource elements with indices <NUM>, <NUM>, and <NUM> in the RBs <NUM>, <NUM>. The UE <NUM>-<NUM> further performs a channel estimation based on the measured signals in those resource elements and the <NUM> DMRSs from the DMRS sequence <NUM> mapped to those resource elements.

The UE complexity in channel estimation process may be higher in this example. The CORESET <NUM> and the CORESET <NUM> are assigned to the same UE and are partially overlapped in the physical resources. The PDCCH resource candidate <NUM> of the CORESET <NUM> and the PDCCH resource candidate <NUM> of the CORESET <NUM> both include the RBs <NUM>, <NUM>. As described supra, the UE <NUM>-<NUM> performs DMRS extraction in channel estimation process for the RBs <NUM>, <NUM> twice, as the DMRSs accompanied with the DCCH resource candidates of different CORESETs have different reference points.

In a second option, the base station <NUM> and the UE <NUM>-<NUM> agrees to use a reference point that is specific and relevant to the bandwidth part <NUM>-<NUM> to map a DMRS sequence <NUM>. Within a symbol period <NUM>, the bandwidth part <NUM>-<NUM> ranges in frequency domain from an RB <NUM> having the lowest frequency to an RB <NUM> having the highest frequency. In one example, the reference point is the RB <NUM>. In particular, this option may be employed when the base station <NUM> signals the CORESET configuration for the CORESET <NUM> and the CORESET configuration for the CORESET <NUM> through MIB or remaining minimum system information (RMSI). During the initial access, the bandwidth part <NUM>-<NUM>, which is the initial active bandwidth part, is defined as frequency location and bandwidth of RMSI CORESET. At the same time, the UE <NUM>-<NUM> has no knowledge of the RB indexing of the initial BWP within the carrier <NUM>. In general, the initial active down-link bandwidth part may be defined as frequency location and bandwidth of RMSI CORESET and numerology of RMSI. PDSCH delivering RMSI are confined within the initial active down-link bandwidth part.

DMRSs from the DMRS sequence <NUM> are mapped to both the PDCCH resource candidate <NUM> of the CORESET <NUM> and the PDCCH resource candidate <NUM> of the CORESET <NUM>. Therefore, the RBs <NUM>, <NUM> carry the same DMRSs for both the PDCCH resource candidate <NUM> and the PDCCH resource candidate <NUM>. Accordingly, the UE <NUM>-<NUM> generates the DMRS sequence <NUM> that can be mapped from the RB <NUM> to the RB <NUM>. The UE <NUM>-<NUM> further determines the RBs <NUM>, <NUM> in the symbol period <NUM> are a part of the PDCCH resource candidate <NUM> and the PDCCH resource candidate <NUM>. Accordingly, the UE <NUM>-<NUM> measures the signals carried by the resource elements with indices <NUM>, <NUM>, and <NUM> in the RBs <NUM>, <NUM>. The UE <NUM>-<NUM> further performs a channel estimation based on the measured signals in those resource elements and the <NUM> DMRSs from the DMRS sequence <NUM> mapped to those resource elements. The results of the channel estimation can be used in blind decoding of both the PDCCH resource candidate <NUM> and the PDCCH resource candidate <NUM>.

As described supra, the bandwidth part <NUM>-<NUM> and the bandwidth part <NUM>-<NUM> are configured to the UE <NUM>-<NUM> and the UE <NUM>-<NUM>, respectively. And the CORESETs of two UEs may be partially overlapped. In the second option, the reference points of DMRS mapping for the UE <NUM>-<NUM> and the UE <NUM>-<NUM> are starting point of the bandwidth part <NUM>-<NUM> and the bandwidth part <NUM>-<NUM>, respectively. With this option, the overlapped region of the CORESETs may not be used to transmit the (group) common PDCCH intended to both the UE <NUM>-<NUM> and the UE <NUM>-<NUM>, as the DMRSs in the overlapping region for the two UEs are different. From the perspective of network, this may restrict the scheduling flexibility. And the signaling overhead of (group) common information is increased. Further, the UE <NUM>-<NUM> does not know the reference point of the DMRS mapping of the UE <NUM>-<NUM>, as the reference point is BWP-specific. Hence, each of the UE <NUM>-<NUM> and the UE <NUM>-<NUM> may not be able to perform DMRS interference cancellation.

<FIG> is a diagram <NUM> illustrating communications between a base station <NUM> and UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G and a third option for DMRS mapping. In particular, the base station <NUM> communicates with the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G on a carrier <NUM> in a slot <NUM>. Further, the UE <NUM>-<NUM> communicates on a bandwidth part <NUM>-<NUM> and the UE <NUM>-<NUM> communicates on a bandwidth part <NUM>-<NUM> with the base station <NUM>.

After determines the resource allocation of the CORESET <NUM>, the UE <NUM>-<NUM> further determines a DMRS mapping in the CORESET <NUM>.

In a third option, the base station <NUM> and the UE <NUM>-<NUM> agrees to use a reference point that is specific and relevant to the carrier <NUM> to map a DMRS sequence <NUM>. Within a symbol period <NUM>, the carrier <NUM> ranges in frequency domain from an RB <NUM> having the lowest frequency to an RB <NUM> having the highest frequency. In one example, the reference point is the RB <NUM>. In particular, this option may be employed when the base station <NUM> signals the CORESET configuration for the CORESET <NUM> and the CORESET configuration for the CORESET <NUM> through UE-specific Radio Resource Control (RRC) signaling. The actual RB indexing of the carrier <NUM> is provided to the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G through the higher layer configurations. The offset from a common reference point RB with index <NUM> to the lowest RB of the SS block accessed by a UE is configured to the UE at least in RRC connected mode. The UE can deduce the RB indexing of the carrier <NUM> based on the offset. The RB indexing is the same for all UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G within the carrier <NUM>. In this option, the common reference point RB with index <NUM> can be reused as the reference point of DMRS mapping.

In the third option, the reference point for starting mapping a DMRS sequence may be the RB with index <NUM> in the carrier. The reference point may be common to all the UEs sharing a wideband component carrier from the network perspective, regardless of whether they are narrow band, carrier aggregation, or wideband UEs.

In this example, the base station <NUM> configures a PDCCH resource candidate <NUM> including the RBs <NUM>, <NUM>, <NUM> in a symbol period <NUM>. The DMRS sequence <NUM> contains <NUM> DMRSs mapped to the RBs <NUM>, <NUM>, <NUM>. As the RBs <NUM>, <NUM>, <NUM> are a part of the PDCCH resource candidate <NUM>, the base station <NUM> use the resource elements with indices <NUM>, <NUM>, and <NUM> in the RBs <NUM>, <NUM>, <NUM> to carry those <NUM> DMRSs.

Further, the base station <NUM> and the UE <NUM>-<NUM> agrees to use a reference point that is specific and relevant to the carrier <NUM> to map a DMRS sequence <NUM>. In one example, the reference point is the RB <NUM>. The base station <NUM> configures a PDCCH resource candidate <NUM> including the RBs <NUM>, <NUM> in the symbol period <NUM>. The DMRS sequence <NUM> contains <NUM> DMRSs mapped to the RBs <NUM>, <NUM>. As the RBs <NUM>, <NUM> are a part of the PDCCH resource candidate <NUM>, the base station <NUM> use the resource elements with indices <NUM>, <NUM>, and <NUM> in the RBs <NUM>, <NUM> to carry those <NUM> DMRSs.

DMRSs from the DMRS sequence <NUM> are mapped to the PDCCH resource candidate <NUM> of the CORESET <NUM>. DMRSs from the DMRS sequence <NUM> are mapped to the PDCCH resource candidate <NUM> of the CORESET <NUM>. Therefore, the RBs <NUM>, <NUM>, which belongs to the PDCCH resource candidate <NUM> and the PDCCH resource candidate <NUM>, carry the DMRSs for both the PDCCH resource candidate <NUM> and the PDCCH resource candidate <NUM>. The UE <NUM>-<NUM> generates the DMRS sequence <NUM> that can be mapped from the RB <NUM> to the RB <NUM>. The UE <NUM>-<NUM> further determines the RBs <NUM>, <NUM>, <NUM> in the symbol period <NUM> are a part of the PDCCH resource candidate <NUM>. The UE <NUM>-<NUM> measures the signals carried by the resource elements with indices <NUM>, <NUM>, and <NUM> in the RBs <NUM>, <NUM>, <NUM>. Further, the UE <NUM>-<NUM> may also have knowledge of the CORESET <NUM> and the PDCCH resource candidate <NUM> as well as the DMRS sequence <NUM>. Therefore, the UE <NUM>-<NUM> may determine the DMRSs from the DMRS sequence <NUM> that are mapped to the RBs <NUM>, <NUM>.

As such, the UE <NUM>-<NUM> can perform a channel estimation based on the measured signals in the RBs <NUM>, <NUM>, <NUM> and the <NUM> DMRSs from the DMRS sequence <NUM> mapped to the RBs <NUM>, <NUM>, <NUM>. Further, the UE <NUM>-<NUM> can determine the DMRSs from the DMRS sequence <NUM> mapped to the RBs <NUM>, <NUM>. The UE <NUM>-<NUM> can apply interference cancellation based on <NUM> DMRSs mapped to the RBs <NUM>, <NUM>. The results of the channel estimation can be used in blind decoding of the PDCCH resource candidate <NUM>.

In certain configurations, each of the DMRS sequence <NUM>, the DMRS sequence <NUM>, the DMRS sequence <NUM>, the DMRS sequence <NUM>, and the DMRS sequence <NUM> may be generated using the Gold sequence.

In certain configurations, DMRSs may be carried in resource elements other than those with indices <NUM>, <NUM>, and <NUM> in an RB. For example, DMRSs may be carried in resource elements with indices <NUM>, <NUM>, <NUM> in an RB.

<FIG> is a flow chart <NUM> of a method (process) for determining a CORESET and perform blind decoding on the CORESET. The method may be performed by a UE (e.g., the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G, the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G, the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G, the apparatus <NUM>, and the apparatus <NUM>').

At operation <NUM>, the UE receives a CORESET configuration of a first CORESET (e.g., the CORESET <NUM>) on a carrier (e.g., the carrier <NUM>). The CORESET configuration indicates a reference location (e.g., the bitmap in the first technique referring to <FIG>) of the first CORESET with reference to a reference point (e.g., the allocation unit <NUM>) in a frequency domain. At operation <NUM>, the UE determines resources occupied by the first CORESET (e.g., the allocation unit <NUM> to the allocation unit <NUM>) in the frequency domain of the carrier based on the reference location and the reference point. At operation <NUM>, the UE performs blind decoding on DCCH resource candidates in a search space carried by the first CORESET to obtain a down-link control channel.

In certain configurations, the reference location is indicated by an integer of allocation units away from the reference point, each of the allocation units including N resource blocks (RBs), N being an integer greater than <NUM>. In certain configurations, N is <NUM>.

In certain configurations, the reference location is indicated by indications (e.g., the bitmap in the first technique referring to <FIG>) of whether each resource block (RB) in the carrier or a bandwidth part of the carrier constitutes the first CORESET. In certain configurations, the CORESET configuration is received through a system information transmission. In certain configurations, the CORESET configuration is received through a Radio Resource Control (RRC) signaling specific to the UE.

In certain configurations, the reference point is a predetermined point (e.g., the allocation unit <NUM>) of the carrier in the frequency domain.

In certain configurations, the reference point is a predetermined point (e.g., the allocation unit <NUM>) of a bandwidth part (e.g., the bandwidth part <NUM>-<NUM>) of the carrier assigned to the UE in the frequency domain.

In certain configurations, the reference point is a point (e.g., the allocation unit <NUM>) at an offset (e.g., <NUM> RBs) from a predetermined point (e.g., RB with index <NUM>) of a bandwidth part (e.g., the bandwidth part <NUM>-<NUM>) of the carrier assigned to the UE in the frequency domain. In certain configurations, the predetermined point is a starting point of the bandwidth part (e.g., the bandwidth part <NUM>-<NUM>). In certain configurations, the reference location is indicated by an integer of allocation units away from the reference point, each of the allocation units including N resource blocks (RBs), N being an integer greater than <NUM>. In certain configurations, the offset is an integer selected from <NUM> to (N-<NUM>) such that a starting point of a second CORESET (e.g., the CORESET <NUM>) is at an integer of allocation units away from the reference point, the second CORESET overlapping with the first CORESET (e.g., the CORESET <NUM>).

<FIG> is a flow chart <NUM> of a method (process) for determining a DMRS sequence mapping. The method may be performed by a UE (e.g., the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G, the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G, the apparatus <NUM>, and the apparatus <NUM>').

At operation <NUM>, the UE receives a first CORESET configuration of a first CORESET (e.g., the CORESET <NUM>) on a carrier (e.g., the carrier <NUM>). At operation <NUM>, the UE determines resources occupied by the first CORESET on the carrier in a frequency domain based on the first CORESET configuration.

At operation <NUM>, the UE determines a first DCCH resource candidate (e.g., the PDCCH resource candidate <NUM>) in the first CORESET, the first DCCH resource candidate including a first set of RBs (e.g., the RBs <NUM>, <NUM>). At operation <NUM>, the UE determines a first sequence of DMRSs (e.g., the DMRS sequence <NUM>, the DMRS sequence <NUM>) that are mapped, starting at a reference point (e.g., the RB <NUM>, the RB <NUM>), to RBs in a predetermined range within the carrier in the frequency domain, the predetermined range containing the first DCCH resource candidate in the frequency domain. At operation <NUM>, the UE determines, with reference to the reference point in the frequency domain, a first reference location of the first set of RBs. At operation <NUM>, the UE determines, based on the first reference location, a first set of DMRSs (e.g., the DMRSs in the RBs <NUM>, <NUM>) from the first sequence of DMRSs, the first set of DMRSs being mapped to the first set of RBs. Subsequently, in certain configurations, the process proceeds to operation <NUM> in <FIG>. In certain configurations, the process proceeds to operation <NUM>.

At operation <NUM>, the UE obtains a channel estimation based on the first set of DMRSs. At operation <NUM>, the UE performs blind decoding of the first DCCH resource candidate based on the channel estimation. At operation <NUM>, the UE determines a second DCCH resource candidate (e.g., the PDCCH resource candidate <NUM>) in a second CORESET (e.g., the CORESET <NUM>) of the UE on the carrier, the second DCCH resource candidate including the first set of RBs (e.g., the RBs <NUM>, <NUM>). At operation <NUM>, the UE preforms blind decoding of the second DCCH resource candidate based on the channel estimation.

In certain configurations, the first reference location is indicated by an integer of RBs away from the reference point. In certain configurations, the reference point is a predetermined point (e.g., the RB <NUM>) of the first CORESET in the frequency domain. In certain configurations, the predetermined range is a range occupied by the first CORESET in the frequency domain. In certain configurations, the reference point is a predetermined point of a bandwidth part of the carrier assigned to the UE in the frequency domain. In certain configurations, the predetermined range is a range occupied by the bandwidth part (e.g., the bandwidth part <NUM>-<NUM>) in the frequency domain. In certain configurations, the first CORESET configuration is received through a system information transmission.

<FIG> is a flow chart <NUM> of a method (process) for determining a DMRS sequence mapping following operation <NUM> in <FIG> in certain configurations. The method may be performed by a UE (e.g., the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G, the UEs <NUM>-<NUM>, <NUM>-<NUM>,. <NUM>-G, the apparatus <NUM>, and the apparatus <NUM>').

In certain configurations, the reference point is a predetermined point (e.g., the RB <NUM>) of a carrier (e.g., the carrier <NUM>) in the frequency domain. The predetermined range is a range occupied by the carrier in the frequency domain. In certain configurations, the first CORESET configuration is received through a Radio Resource Control (RRC) signaling specific to the UE.

At operation <NUM>, UE determines a second DCCH resource candidate (PDCCH resource candidate <NUM>) in a second CORESET (e.g., CORESET <NUM>) on the carrier, the second DCCH resource candidate including the first set of RBs (e.g., the RBs <NUM>, <NUM>), the second CORESET being assigned to a second UE (e.g., the UE <NUM>-<NUM>). At operation <NUM>, the UE determines a second sequence of DMRSs (e.g., the DMRS sequence <NUM>) that are mapped, starting at the reference point, to the RBs in the predetermined range, the second sequence of DMRSs being utilized by the second UE. At operation <NUM>, the UE determines, based on the first reference location, a second set of DMRSs from the second sequence of DMRSs, the second set of DMRSs being mapped to the first set of RBs. The channel estimation is obtained further based on the second set of DMRSs.

At operation <NUM>, the UE obtains a channel estimation based on the first set of DMRSs and the second set of DMRSs. At operation <NUM>, the UE performs blind decoding of the first DCCH resource candidate based on the channel estimation.

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different components/means in an exemplary apparatus <NUM>. The apparatus <NUM> may be a UE. The apparatus <NUM> includes a reception component <NUM>, a CORESET configuration component <NUM>, a DMRS mapping component <NUM>, a blind decoding component <NUM>, and a transmission component <NUM>.

In one aspect, the reception component <NUM> receives a CORESET configuration of a first CORESET (e.g., the CORESET <NUM>) on a carrier (e.g., the carrier <NUM>) from a base station <NUM>. The CORESET configuration indicates a reference location (e.g., the bitmap in the first technique referring to <FIG>) of the first CORESET with reference to a reference point (e.g., the allocation unit <NUM>) in a frequency domain. The CORESET configuration component <NUM> determines resources occupied by the first CORESET (e.g., the allocation unit <NUM> to the allocation unit <NUM>) in the frequency domain of the carrier based on the reference location and the reference point. The blind decoding component <NUM> performs blind decoding on DCCH resource candidates in a search space carried by the first CORESET to obtain a down-link control channel.

In another aspect, the reception component <NUM> receives a first CORESET configuration of a first CORESET (e.g., the CORESET <NUM>) on a carrier (e.g., the carrier <NUM>) from the base station <NUM>. The CORESET configuration component <NUM> determines resources occupied by the first CORESET on the carrier in a frequency domain based on the first CORESET configuration.

The CORESET configuration component <NUM> determines a first DCCH resource candidate (e.g., the PDCCH resource candidate <NUM>) in the first CORESET, the first DCCH resource candidate including a first set of RBs (e.g., the RBs <NUM>, <NUM>). The DMRS mapping component <NUM> determines a first sequence of DMRSs (e.g., the DMRS sequence <NUM>, the DMRS sequence <NUM>) that are mapped, starting at a reference point (e.g., the RB <NUM>, the RB <NUM>), to RBs in a predetermined range within the carrier in the frequency domain, the predetermined range containing the first DCCH resource candidate in the frequency domain. The DMRS mapping component <NUM> determines, with reference to the reference point in the frequency domain, a first reference location of the first set of RBs. The DMRS mapping component <NUM> determines, based on the first reference location, a first set of DMRSs (e.g., the DMRSs in the RBs <NUM>, <NUM>) from the first sequence of DMRSs, the first set of DMRSs being mapped to the first set of RBs.

In certain configurations, the blind decoding component <NUM> obtains a channel estimation based on the first set of DMRSs. The blind decoding component <NUM> performs blind decoding of the first DCCH resource candidate based on the channel estimation. The CORESET configuration component <NUM> determines a second DCCH resource candidate (e.g., the PDCCH resource candidate <NUM>) in a second CORESET (e.g., the CORESET <NUM>) of the UE on the carrier, the second DCCH resource candidate including the first set of RBs (e.g., the RBs <NUM>, <NUM>). The blind decoding component <NUM> preforms blind decoding of the second DCCH resource candidate based on the channel estimation.

The CORESET configuration component <NUM> determines a second DCCH resource candidate (PDCCH resource candidate <NUM>) in a second CORESET (e.g., CORESET <NUM>) on the carrier, the second DCCH resource candidate including the first set of RBs (e.g., the RBs <NUM>, <NUM>), the second CORESET being assigned to a second UE (e.g., the UE <NUM>-<NUM>). The DMRS mapping component <NUM> determines a second sequence of DMRSs (e.g., the DMRS sequence <NUM>) that are mapped, starting at the reference point, to the RBs in the predetermined range, the second sequence of DMRSs being utilized by the second UE. The DMRS mapping component <NUM> determines, based on the first reference location, a second set of DMRSs from the second sequence of DMRSs, the second set of DMRSs being mapped to the first set of RBs. The channel estimation is obtained further based on the second set of DMRSs.

The blind decoding component <NUM> obtains a channel estimation based on the first set of DMRSs and the second set of DMRSs. The blind decoding component <NUM> performs blind decoding of the first DCCH resource candidate based on the channel estimation.

<FIG> is a diagram <NUM> illustrating an example of a hardware implementation for an apparatus <NUM>' employing a processing system <NUM>. The apparatus <NUM>' may be a UE. The processing system <NUM> may be implemented with a bus architecture, represented generally by a bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> links together various circuits including one or more processors and/or hardware components, represented by one or more processors <NUM>, the reception component <NUM>, the CORESET configuration component <NUM>, the DMRS mapping component <NUM>, the blind decoding component <NUM>, the transmission component <NUM>, and a computer-readable medium / memory <NUM>. The bus <NUM> may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, etc..

The processing system <NUM> may be coupled to a transceiver <NUM>, which may be one or more of the transceivers <NUM>. The transceiver <NUM> is coupled to one or more antennas <NUM>, which may be the communication antennas <NUM>.

The transceiver <NUM> provides a means for communicating with various other apparatus over a transmission medium. The transceiver <NUM> receives a signal from the one or more antennas <NUM>, extracts information from the received signal, and provides the extracted information to the processing system <NUM>, specifically the reception component <NUM>. In addition, the transceiver <NUM> receives information from the processing system <NUM>, specifically the transmission component <NUM>, and based on the received information, generates a signal to be applied to the one or more antennas <NUM>.

The processing system <NUM> includes one or more processors <NUM> coupled to a computer-readable medium / memory <NUM>. The one or more processors <NUM> are responsible for general processing, including the execution of software stored on the computer-readable medium / memory <NUM>. The software, when executed by the one or more processors <NUM>, causes the processing system <NUM> to perform the various functions described supra for any particular apparatus. The computer-readable medium / memory <NUM> may also be used for storing data that is manipulated by the one or more processors <NUM> when executing software. The processing system <NUM> further includes at least one of the reception component <NUM>, the CORESET configuration component <NUM>, the DMRS mapping component <NUM>, the blind decoding component <NUM>, and the transmission component <NUM>. The components may be software components running in the one or more processors <NUM>, resident/stored in the computer readable medium / memory <NUM>, one or more hardware components coupled to the one or more processors <NUM>, or some combination thereof. The processing system <NUM> may be a component of the UE <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>, the RX processor <NUM>, and the communication processor <NUM>.

In one configuration, the apparatus <NUM>/apparatus <NUM>' for wireless communication includes means for performing each of the operations of <FIG>.

As described supra, the processing system <NUM> may include the TX Processor <NUM>, the RX Processor <NUM>, and the communication processor <NUM>. As such, in one configuration, the aforementioned means may be the TX Processor <NUM>, the RX Processor <NUM>, and the communication processor <NUM> configured to perform the functions recited by the aforementioned means.

Claim 1:
A method of wireless communication of a user equipment, in the following also referred to as UE, comprising:
determining a first down link control channel, in the following also referred to as DCCH, resource candidate in a first control resource set, in the following also referred to as CORESET, on a carrier, the first DCCH resource candidate including a first set of resource blocks, in the following also referred to as RBs, (<NUM>);
determining a first sequence of Demodulation Reference Signals, in the following also referred to as DMRSs, that are mapped, starting at a reference point, to RBs in a predetermined range within the carrier in a frequency domain, the predetermined range containing the first DCCH resource candidate in the frequency domain (<NUM>);
determining, with reference to the reference point in the frequency domain, a first reference location of the first set of RBs as the lower boundary in the frequency domain of the first set of RBs (<NUM>);
determining, based on the first reference location, a first set of DMRSs from the first sequence of DMRSs, the first set of DMRSs being mapped to the first set of RBs (<NUM>);
obtaining a channel estimation based on the first set of DMRSs (<NUM>); and
performing blind decoding of the first DCCH resource candidate based on the channel estimation (<NUM>);
characterized in that
the reference point is an allocation unit at an offset of RBs from a predetermined point of a bandwidth part of the carrier assigned to the UE in the frequency domain, which offset is received at the UE through higher-layer signaling with a resource allocation of the first CORESET;
the predetermined point is a starting point of the bandwidth part; and
the first reference location is indicated by an integer of allocation units away from the reference point, each of the allocation units including N RBs, N being an integer greater than <NUM>.