WO2018232753A1

WO2018232753A1 - Transmission of control messages in wireless communication

Info

Publication number: WO2018232753A1
Application number: PCT/CN2017/089843
Authority: WO
Inventors: Shujuan Zhang; Zhaohua Lu; Yu Ngok Li; Bo Gao; Yijian Chen; Chuangxin JIANG
Original assignee: Zte Corporation
Priority date: 2017-06-23
Filing date: 2017-06-23
Publication date: 2018-12-27
Also published as: CN110785943A

Abstract

Methods, systems, and devices are described for implementing beam indication in wireless communication. In one exemplary aspect, a method of wireless communication is disclosed. The method includes receiving a feedback message including one or more indicators from a wireless communication node, wherein each of the one or more indicators indicates a resource corresponding to a reference signal; and transmitting a message that includes a value indicative of at least one indicator selected from the one or more indicators to the wireless communication node.

Description

TRANSMISSION OF CONTROL MESSAGES IN WIRELESS COMMUNICATION

TECHNICAL FIELD

This patent document is directed generally to wireless communications.

BACKGROUND

The mobile communication technologies are moving the world toward an increasingly connected and networked society. In comparison with the existing wireless networks, the next generation systems and wireless communication techniques will need to support a much wider range of use-case characteristics and provide a much more complex range of network access techniques.

SUMMARY OF PARTICULAR EMBODIMENTS

This patent document relates to techniques, systems, and devices for beam indication in wireless communication.

In one exemplary aspect, a method of wireless communication is disclosed. The method includes receiving a feedback message including one or more indicators from a wireless communication node, wherein each of the one or more indicators indicates a resource corresponding to a reference signal； and transmitting a control message that includes a value indicative of at least one indicator selected from the one or more indicators to the wireless communication node.

In another exemplary aspect, a method of wireless communication is disclosed. The method includes transmitting a feedback message including one or more indicators to a wireless communication node, wherein each of the one or more indicators indicates a resource corresponding to a reference signal； receiving a control message that includes a value indicative of at least one indicator selected from the one or more indicators； and performing transmission using the resource indicated by the indicator based on the value.

In another exemplary aspect, a method of wireless communication is disclose. The method includes receiving a feedback message based on a reference signal from a wireless communication node, the feedback message including channel state information of a communication link, and transmitting a message to the wireless communication node to indicate a receipt status of the feedback message.

In another exemplary aspect, a method of wireless communicating is disclosed. The method includes transmitting a feedback message including resource information to a wireless communication node, and receiving a message from the wireless communication node. The message is indicative of a receipt status of the feedback message.

In yet another exemplary aspect, a method of wireless communication is disclosed. The method includes establishing an association between a first reference signal in a time window and a second reference signal； and transmitting or receiving the second reference signal based on the association.

The above and other aspects and their implementations are described in greater detail in the drawings, the description and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a Multiple-input and multiple-output (MIMO) system including m transmitting antennas and n receiving antennas.

FIG. 2 shows an example of beamforming that improves carrier-to-noise interference plus noise ratio (CINR) by matching antenna gain to a specific user entity (UE) position.

FIG. 3 shows an example of beam indication performed by the base station.

FIG. 4 shows an example of a base station transmitting three Channel State Information Reference Signals (CSI-RSs) to a user entity and receiving a corresponding feedback from the user entity.

FIG. 5A shows an example of a base station sending confirmation messages only for the two most recent feedback messages from a UE.

FIG. 5B shows an example of timing order of the feedback messages.

FIG. 6A shows an example of long delay from the time an UE sends its feedback to the time the base station sends a Downlink Control Indicator (DCI) message for beam indication when a mapping is established via Radio Resource Control (RRC) .

FIG. 6B shows an example of short delay from the time an UE sends its feedback to the time the base station sends a DCI message for beam indication when a mapping is established via DCI.

FIG. 7 is a flowchart representation of a wireless communication method.

FIG. 8A shows an example of reference signal with different beams in different time windows.

FIG. 8B shows an example of a window of a Channel State Information Reference Signals (CSI-RS) associated with a reporting setting or a report.

FIG. 9 an example of a wireless communication system where techniques in accordance with one or more embodiments of the present technology can be applied.

FIG. 10 is a block diagram representation of a portion of a radio station.

FIG. 11 is a flowchart representation of a wireless communication method.

FIG. 12 is another flowchart representation of a wireless communication method.

FIG. 13 is another flowchart representation of a wireless communication method.

FIG. 14 is another flowchart representation of a wireless communication method.

FIG. 15 is another flowchart representation of a wireless communication method.

DETAILED DESCRIPTION

The rapid growth of wireless communications and advances in technology is partly to satisfy the demand for greater capacity and higher data rates. Other aspects, such as energy consumption, device cost, spectrum resource allocation, and latency are also factors in the success of future networks.

Multiple-input and multiple-output (MIMO) is a method for multiplying the capacity of a radio link using multiple transmitting and receiving antennas to exploit multipath propagation. FIG. 1 shows an example of a MIMO system including m transmitting antennas 101-1, 101-2, …, 101-m, and n receiving antennas 102-1, 102-2, …, 102-m. The receiver 112 receives signal y that results from input signal vector x from transmitter 110 being multiplied by a transmission matrix H. MIMO has become an essential element of wireless communication standards including IEEE 802.11n (Wi-Fi) , IEEE 802.11ac (Wi-Fi) , HSPA+ (3G) , WiMAX (4G) , and Long Term Evolution (4G LTE) . In particular, enhanced MIMO capabilities has been added to 4G LTE wireless communication systems. For example, the reference signal structure is enhanced to include UE-specific reference signal, such as Demodulation Reference Signal (DMRS) , for demodulation of Physical Downlink Shared Channel (PDSCH) . In addition, Channel State Information Reference Signals (CSI-RSs) allow the UE downlink Channel State Information (CSI) measurement. Recent releases of LTE also improved Downlink Control Indicator (DCI) formats to allow a base station to tell a user entity (UE) that it can assume a quasi-co-location of the antenna ports with respect to Dopper shift, Dopper spread, average delay, and delay spread. Coordinated Multi Point Transmission (CoMP) further allows a transmitting antenna to be physically located on a different base station to achieve MIMO. In 5G New Radio (5G-NR) access technology, MIMO will continue to play an important role.

Under MIMO, the transmitter and the receiver can perform beamforming before or during data transmission. FIG. 2 shows an example of beamforming that improves carrier-to-noise interference plus noise ratio (CINR) by matching antenna gain to a specific UE position. For example, beamforming allows base station gNB1 201 to modify its transmit signals to give the best CINR at the output of the channel in the direction of UE1 203. Similarly, base station gNB2 202, by performing beamforming, can modify its transmit signals to give the best CINR at the output of the channel in the direction of UE2 204.

FIG. 3 shows an example of beam indication performed by the base station. In FIG. 3, base station gNB 301 has twelve beams for transmission. UE 303 has nine beams for reception. The base station gNB 301 sends one or more CSI-RS antenna ports and/or CSI-RS resources to UE 303 to determine which beams it can use for subsequent transmission with UE 303. Each port or each resource may correspond to a particular beam. In this particular example, base station gNB 301 sends twelve coded CSI-RS resources 305-0, 305-1, …, 305-11 representing the twelve beams to UE 303. UE 303 selects three of them among the twelve beams: 305-2, 305-5, and 305-9. It then sends back a feedback message including CSI-RS resources indicators for CSI-RS resources {305-2, 305-5, 305-9} . After base station gNB 301 receives this feedback message, it can select one or more beams of the CSI-RS resources indicators included in the feedback. For example, it may select beam of 305-5 for subsequent transmission. It may also select multiple beams such as beams of 305-2 and 305-5 for subsequent transmission. The base station gNB 301 then informs UE 303 which of the beam indicated by CSI-RS resources among {305-2, 305-5, 305-9} it will use so that UE 303 can use a suitable receiving antenna port/beam for reception.

As shown in FIG. 3, when there are multiple beams between the transmitting end and the receiving end, it is desirable for the base station to indicate to the UE which beam (s) it will use for subsequent transmission so that UE can select the suitable receiving antenna port (s) . The base station can inform the UE by including a CSI-RS Resource Indicator (CRI) in a DCI message to transmit to the UE. However, when the base station has a large amount of available beams, indicating multiple CRIs directly in a DCI increases signaling overhead between the base station and the corresponding UE. Therefore, there remains a need for improved techniques to facilitate more efficient beam indication between a base station and a corresponding UE. This patent document describes techniques that allows a base station to indicate beam usage using a small amount of bits included in a control message, thereby minimizing the impact of beam indication on signaling overhead. The techniques disclosed herein also allow the base station to inform a UE about a reference signal such as CSI-RS that is quasi-co-located with DMRS ports/CSI-RS/SRS ports. Then UE can use the reference signal to get the large-scale properties of the channel of DMRS/CSI-RS/SRS.

Overview

As previously discussed, a base station may perform beamforming with multiple UEs prior to or during data transmission. The base station, or a transmitting antenna physically located on a different base station, may send one or more reference signals that correspond to a plurality of antenna ports to a particular UE. In some embodiments, the base station may send a UE-specific reference signal. The use of UE-specific reference signal improves carrier-to-noise interference plus noise ratio (CINR) by matching antenna gain to a specific UE position. For example, the reference signal can be a CSI-RS that includes up to 16 antenna ports, or other types of downlink RSs. FIG. 4 shows an example of a base station 400 transmitting three CSI-

RSs

401, 402, and 403 to a UE 410 and receiving a corresponding feedback message 404 from UE 410. In this particular example, CSI-RS 1 (401) is associated with an antenna port A, CSI-RS 2 (402) is associated with an antenna port B, and CSI-RS 3 (403) is associated with an antenna port C.

Once UE 410 receives the reference signals, it sends a feedback message 404 to the base station to indicate its preferred beam (s) . The feedback message 404 can include information such as Pre-coding Matrix Indicator (PMI) , Rank Indicator (RI) , and Channel Quality Indicator (CQI) . The feedback message 404 can also include other resources indicators that correspond to a preferred beam. The resources indicators may include CSI-RS resource indicators, CSI-RS resource set indicator, CSI-RS resource setting indicator, antenna port indicator, timing information indicator of the reference signals , time window indicator that may be obtained based on the information of measurement restriction, relative power indicators (RPIs) , or other types of indicators. In this particular example, the feedback message 404 includes a CS-RS resource indicators (CRI) for CSI-RS 2 to indicate that the beam corresponds to CSI-RS 2 is preferable. The feedback message 404 can also include more than one resource indicators when the UE determines that multiple beams are favorable. In some embodiments, the CRI can be obtained from a resource set. The CRI can also be obtained from a resource setting that includes more than two resource sets. For example, the CRI in a resource setting can be defined as follows:

CRI in a resource setting ＝ index of resource set in the resource setting *number of the resources in a resource set + the CRI of the resource in a resource set.

The CRI can also be the logic index of the resource in a resource set and the resource set can select resources from a resource setting.

In some embodiments, a CRI included in the feedback has an association with the DMRS antenna port (s) . In the example shown in FIG. 4, UE 410 reports CRS-RS 2 in its feedback message 404 after determining that the beam corresponding to CS-RS 2 is favorable. In some embodiments, UE 410 may learn from the base station that the antenna port corresponding to CS-RS 2 is a port that is quasi-co-located (QCL) with a DMRS port. For example, CSI-RS 2 is quasi-co-located with an antenna port DMRS used in uplink transmission. The transmitter spatial filter of uplink DMRS/SRS can also be obtained by receiving spatial filter of CSI-RS 2.

After the base station 400 receives the feedback message 404, it can select CSI-RS 2 for subsequent transmission with UE 410. It then sends an indication to inform UE 410 of its beam/antenna port selection. In order to minimize signaling overhead between the base station 400 and UE 410, the base station 400 can include an index value comprising only a few bits, instead of a full CRI, for such indication. In order to do so, both the base station 400 and UE 410 needs to store a mapping between index values and corresponding indicators for the antenna ports.

For example, as shown in Table 1, a mapping between index values and CSI-RS resource indicators can be established. The base station can simply include the index value for the indicator in a message for data transmission. The base station may also include the index value in a message for next stage channel measurement.

Table 1 An example of mapping between index values and indicators

Index

Indicator

0	CSI-RS resource1
1	CSI-RS resource2
2	CSI-RS resource5
3	CSI-RS resource7

In the example shown in Table 1, each of the CSI-RS resource indicators corresponds to an antenna port. The base station can essentially use two bits to indicate which antenna port to be used for subsequent transmission. When the index value is ‘0’ and the index value is included in a message for a data transmission, the UE can receive the DMRS and data using the receiving beam obtained from the receiving beam of CSI-RS resource1. The UE may also get the large-scale properties of DMRS and data derived from the large-scale properties of CSI-RS resource 1. The large-scale properties include one or more of the following properties: delay spread, Doppler spread, Doppler shift, average gain, and average delay. In addition, the UE may get spatial receiver (Rx) parameters which can include one or more following parameters : Angle of Arrival (AoA) , Dominant AoA, average AoA, Power Angular Spectrum (PAS) of AoA, average Angle of Departure (AoD) , Power Azimuth Spectrum (PAS) of AoD, transmit/receive channel correlation, transmit/receive beamforming, and spatial channel correlation etc.

In some embodiments, the UE and the base station can update the association between of the index value and an indicator after it receives a feedback message from UE. For example, the UE and/or the base station can compare the information of the indicator in the feedback message and the information of the indicators stored in the mapping. If the UE and/or the base station find that the information is the same, it can replace the corresponding indicator stored in the mapping with the indicator in the feedback message. The information of the indicators includes one or more following parameters: timing information, an index of a reporting setting associated with the indicator, an index of a link associated with the indicator, an index of a measurement setting associated with the indicator, an index of a resource setting including the resource indicated by the indicator, an index of a resource set including the resource indicated by the indicator, an index of a resource including the resource indicated by the indicator, the channel and/or signal quality information of the resource indicated by the indicator, an ordinal number of the indicator in a set of indicators, the Tx spatial filter, the Rx spatial filter, and the large-scale properties of the resource indicated by the indicator. For example the UE and/or the base station finds that there is a indicator (such as CRI1) associated with report 1 and it receives a feedback message including an indicator (such as CRI6) for report1, then the UE and/or the base station can replace the indicator (such as CRI1) in the mapping with the indicator (such as CRI6) in the new feedback message.

For instance, CSI-RS1 is a non-precoded reference signal that corresponds to multiple antenna ports. The base station can refine CSI-RS1 into a collection of CRIs: {CSI-RS1-1, CSI-RS1-2, …, CSI-RS1-Q} by configuring that there is a QCL assumption between the CSI-RS 1 and the CSI-RS 1-j, j＝1, 2, …Q or there is another association between the CSI-RS 1 and the CSI-RS 1-j, j＝1, 2, …Q. The base station and/or the UE stores a mapping as shown in table 1 prior to receiving the feedback message including the selection results among the CSI-RS 1-j, j＝1, 2, …Q. For example, the base station can update the entries in Table 1 to entries in Table 2 after it receives a feedback message including CSI-RS 1-2 among other CSI-RS 1-j.

Table 2 An example of updating mapping between index values and indicators

Index	Indicator
0	CSI-RS resource1-2
1	CSI-RS resource2
2	CSI-RS resource5
3	CSI-RS resource7

In some embodiments, the base station may choose to send the response when it receives a channel state information from a UE in order to inform UE whether it successfully receives the feedback. The base station can transmit the response only when the feedback satisfies a pre-determined set of criteria. For example, the base station transmits the response only when the feedback includes a indicator, such as one or more following indicators: CSI-RS port indicator, CSI-RS resource indicator, resource set indicator, resource setting indicator, time window indicator, or RPI (Relative power indicator) . In some implementations, the time window indicator can be obtained using the measure restriction information. If the feedback message only includes information such as PMI, CQI, or RI, the base station can remain silent without transmitting the response. The base station may further examine values of the indicators to decide if it should send the response. For example, only when a RPI vector includes zero element, or only when a RPI vector includes an element having a value less than a predetermined threshold, the base station transmits the response. If the base station finds that the RPI vector doesn’t not include zero element, or all the elements it includes have a value larger than a predetermined threshold, the base station can choose not to transmit the response for the feedback message. The UE can update the mapping with the indicator in the feedback message only when the UE receives the response and the response means that the base station has received the feedback message successfully. In some implementations, the UE can perform other actions based on the response.

In some embodiments, the base station may receive a large amount of feedback messages from a UE. For the purpose of minimizing signaling overhead of the response between the base station and the corresponding UE, it is desirable for the base station to limit the number of feedback messages which it sends responses to. FIG. 5A shows an example of a base station sending a DCI message 509 including the response only for the two most

recent feedback messages

506 and 508 from a UE. In FIG. 5A, a base station sends a first DCI message DCI1 (501) at time t0. Subsequently, it receives L (e.g., seven) feedback messages 502-508 from a UE until it sends a DCI message DCI2 (509) . The base station first checks whether the feedback message includes information that satisfies a pre-determined set of criteria. In this particular example,

feedback messages

502, 505, 507 do not contain necessary information that satisfies the predetermined set of criteria to trigger the base station to send a response for the feedback messages. On the other hand, the base station finds that M (e.g., four)

feedback messages

503, 504, 506, and 508 include necessary information. However, in order to control signaling overhead, the base station only includes responses for the N (e.g., two) most

recent feedback messages

506 and 508 in its DCI2 message (509) . The base station then sends DCI2 message (509) at t1. Further, the DCI1 and the DCI2 can be the same type. For example the DCI1 and the DCI2 are both DL-Grant and/or both include beam indication field. The beam indication filed can also be the field indicating a QCL relationship between two reference signals.

Defining Meanings of the Mapping

When a base station receives a small number of feedback messages from a corresponding UE, it is not necessary to assign an additional meaning to the index value (see Table 1 and Table 2) . However, when the corresponding UE sends a large amount of feedback (e.g., in CoMP scenarios) , it is desirable to assign a meaning to the index value to facilitate maintenance of the mapping at both the base station and the UE. Moreover, based on the complexity of the feedback messages, one or more mappings can be stored, each of which accommodates one type of associations between the index values and resource indicators.

In some embodiments, index values can simply indicate an indicator with an timing information. For example, index values can correspond to the transmission or receipt time of the indicator. Table 3 shows an example of mapping ordered by receiving time of the indicator. In this example, the most recently received indicator (e.g., the latest slot) is placed at index 0, while the oldest indicator (e.g., the fourth last slot) is placed at index 3. In some implementation, the UE and the base station can agree upon a predetermined interval (e.g., K_i slots) between each of the feedback messages. For example, feedback message was received at the fourth last slot, n. The next feedback message was received at the third last slot, n+K_i. Subsequent feedback messages were received at the second last slot, n+K_i + K_j, and the latest slot, n+K_i + K_j + K_l. The base station then can send a DCI message including the index value at a later slot. K_i, K_j, and K_l can have same or different values, such as zero or integers larger than zero. In some implementation, the UE and the base station can agree upon an interval between each of the feedback messages and the transmission or receipt time of the index value so long as the interval is larger than a predetermined interval .

Table 3 An example of mapping ordered by receiving time of feedback messages

Index	Index Meaning	Indicator
0	CRI received at the latest slot	CSI-RS resource1
1	CRI received at the second last slot	CSI-RS resource2
2	CRI received at the third last slot	CSI-RS resource5
3	CRI received at the fourth last slot	CSI-RS resource7

As shown in Fig 5B, the base station and the UE both can obtain Table 4 based on criteria given by Table 3. The latest feedback message that includes information satisfying a set of pre-determined criteria was received in slot n1. Its corresponding indicator is placed at index 0. Similarly, the second last qualified feedback message was received in slot n2, and its corresponding indicator is placed at index 2. The oldest qualified feedback message was received at slot n4, and its corresponding indicator is placed at index 3. Similarly, the UE and the base station can agree upon a predetermined interval (e.g., K slots) between each of the feedback message. For example, feedback message was received at the fourth last slot, n4. The next feedback message was received at the third last slot, n3＝n4+K. Subsequent feedback messages were received at the second last slot, n2＝n3+K, and the latest slot, n1＝n2+K. The base station then can send a DCI message including the index value at slot n1+K. K can be zero or an integer larger than zero.

Table 4 Another example of mapping ordered by receiving time of feedback messages

Index

Index Meaning

Indicator

0	CRI received at slot n1	CSI-RS resource6
1	CRI received at slot n2	CSI-RS resource2
2	CRI received at slot n3	CSI-RS resource5
3	CRI received at slot n4	CSI-RS resource7

While the index values in the above examples are ordered by receiving time of feedback messages, it is understood that other types of mapping based on timing information can also be used. The base station and the UE can establish the sample mapping between the index value and the corresponding meaning as shown in first column and the second column of Tables 3-4 using another predetermined rule. The rule can also be communicated between the base station and the UE using a message such as high layer control message before slot n4 or before slot n in which the base station sends a DCI including the index value.

In some embodiments, the index values may indicate an indicator for a report settings. Table 5 shows an example of mapping in which the index values correspond to indicators of various report settings. The base station and the UE can establish the mapping of index value and the Index meaning using a predetermined rule and/or using a message. For example, when UE’s feedback indicator indicates CSI-RS resource 1for report setting 1, the UE and the base station know that the index value “0” is directed to CSI-RS resource1. when UE’s feedback indicator indicates CSI-RS resource 2 for report setting 2, the UE and the base station know that the index value “1” is directed to CSI-RS resource2, and so on. If subsequently, the UE feedbacks indicator indicates CSI-RS resource 6 for report setting 1 (not shown in Table 5) , then the UE and the base station know that the index value “0” is directed to the CSI-RS resource 6. The same indicator for different report setting may correspond to different resource. For example the indicator 1 is corresponding to the resource 1 of resource setting 1 associated with report setting 1 and the indicator 1 is corresponding to the resource 1 of resource setting 2 associated with report setting 2.

Table 5 An example of mapping in which index values mean report settings

Index	Index Meaning	Resource Indicator
0	CRI for report setting 1	CSI-RS resource1
1	CRI for report setting 2	CSI-RS resource2
2	CRI for report setting 3	CSI-RS resource5
3	CRI for report setting 4	CSI-RS resource7

In some embodiments, the index values can be associated to a CRI with a channel quality, such as a reference signal received power (RSRP) value, a reference signal received quality (RSRQ) value, a CQI (channel quality indicator) , or other channel quality values. For example, the UE and base station establish a mapping between the index value and the index meaning as shown in Table 6 using a predetermined rule or via a control message. The UE includes {CRI3, CRI2, CRI5, CRI7} in its feedback message, each of the CRI corresponding to {CSI-RS resource3, CSI-RS resource2, CSI-RS resource5, CSI-RS resource7} respectively. The UE also includes the RSRP value for {CSI-RS resource3, CSI-RS resource2, CSI-RS resource5, CSI-RS resource7} in its feedback message. In this particular example, the RSRP values are {40dB, 20dB, 10dB, 5dB} respectively. Then, based on the corresponding RSRP value, the UE and the base station know that the index value “0” is directed the resource of CSI-RS resource3 as shown in third column of Table 6.

Table 6 An example of mapping of index values associated with channel quality

Index	Index Meaning	Indicator
0	CRI with the best channel quality	CSI-RS resource3
1	CRI with the second best channel quality	CSI-RS resource2
2	CRI with the third best channel quality	CSI-RS resource5
3	CRI with the fourth best channel quality	CSI-RS resource7

Index values can also have compound meanings. For example, in some cases, one feedback message may include one or more resource indicators. The index values can not only indicate the transmission/receipt time of the indicators, but also the order of indicators in a feedback message.

Table 7 shows an example of mapping in which index values show an order of CRIs included in a feedback message, as well as the receiving time of the indicators. The UE and the base station establish the mapping between the index values and the corresponding meanings as shown in Table 7. The order of the slot is determined by the time-domain gap between the slot for the feedback message including CRI and the slot for the DCI message including the index value. For example, feedback message A includes three CRIs: {CSI-RS resource3, CSI-RS resource2, CSI-RS resource 5} . These indicators were received at slot k. Prior to receiving the feedback message A, the base station received another feedback message B at slot k-5. Feedback message B includes one CRI: CSI-RS resource 7. The mapping is arranged accordingly based on the order of CRIs in the feedback messages, and the time when the feedback messages are received.

Table 7 An example of mapping in which index values indicate orders of CRIs

Index	Index Meaning	Indicator
0	First CRI in feedback A received at latest slot	CSI-RS resource3
1	Second CRI in feedback A received at latest slot	CSI-RS resource2
2	Third CRI in feedback A received at latest slot	CSI-RS resource5
3	First CRI in feedback B received at second last slot	CSI-RS resource7

It should be noted that, in the above description, various meanings are provided as examples to facilitate the understanding of the disclosed techniques. It is, however, understood that other meanings, such as various resource settings, measurement settings, or links between various resource settings and report settings, may be used for by the index values to facilitate the maintenance of the mapping. Index values may also have compound meanings to allow the communication nodes to manage the associations between the resource indicators and beams/antenna ports more efficiently.

In some embodiments, index value can be understood as an indicator of a parameter set. The parameter set includes information about the indicator or the feedback message. The information can be used to distinguish one indicator among many indicator feedback by UE in order to facilitate the maintenance of the mapping. The information includes one or more following information: timing information of the resource indicated by the indicator, timing information of the feedback message including the indicator, an index of a reporting setting associated the indicator, an index of a link associated the indicator, an index of a measurement setting associated the indicator, an index of a resource setting including the resource indicated by the indicator, an index of a resource set including the resource indicated by the indicator, an index of a resource including the resource indicated by the indicator, a channel and/or signal quality information of the resource indicated by the indicator, an ordinal number of the indicator in a set of indicators. Above information for the indicator can be configured by the base station when the base station configures the mapping or obtained using a predetermined rule. The UE can get the indicator indicated by the index value based on the information. In particular, in the above examples shown in Tables 3-7, the mapping between the index values and the indicators is established based on CRI. It is, however understood that the mapping between the index values and the indicators can also be established by both the CRIs included in feedback messages and reference signals such as DMRS/CSI-RS/SRS. For example, the CSI-RS resource and/or the CSI-RS port indicated by the indicator have a quasi-co-location relationship with the DMRS when the index value is in a message for data transmission such as DL-Grant. The CSI-RS resource and/or the CSI-RS port indicated by the indicator also can have quasi-co-location relationship with the CSI-RS/SRS when the value index is in a message for triggering a the CSI-RS /SRS for next stage channel measurement. In some embodiments, the compound meaning of the index changes Table 6 to Table 8 as shown below.

Table 8 Another example of mapping of index values associated with channel quality

In the particular example shown in Table 8, if the CRI with the best quality is CRI3 corresponding to CSI-RS resource 3, the UE receives the index value ‘0’ information from the base station and the index value in a message for a data transmission. The UE can receive the DMRS and data using the receiving beam obtained from the receiving beam of CSI-RS resource1. The UE can further obtain the large-scale properties of DMRS and data derivded from the large-scale properties of CSI-RS resource 3. The large-scale properties include one or more following properties: delay spread, Doppler spread, Doppler shift, average gain, and average delay.

In some embodiments, UE can get spatial Rx parameters which include one or more of parameters: AoA, Dominant AoA, average AoA, Power Angular Spectrum (PAS) of AoA, average AoD, PAS of AoD, transmit/receive channel correlation, transmit/receive beamforming, spatial channel correlation etc. In some embodiments, the index values also indicate the association between the Rx spatial filter of the CSI-RS indicated by the indicator and the Rx spatial filter of the DMRS. The UE can get spatial Rx spatial filter of DMRS based on the Rx spatial filter of CSI-RS. The association can also be about the Rx spatial filter of the CSI-RS indicated by the indicator and the Tx spatial filter of the SRS/DMRS of uplink. The UE can get spatial Tx spatial filter of SRS/DMRS of uplink based on the Rx spatial filter of CSI-RS.

Minimizing Delay

In some embodiments, the mapping of index values and corresponding resource indicators can be established via high level signaling, such as Radio Resource Control (RRC) . Table 9 shows an example of mapping established via RRC. Examples shown in Table 1-8 can also be established via RRC message.

Table 9 An example of mapping established via RRC

Index	Index Meaning	Indicator
0	First entry established by RRC	CSI-RS resource1
1	Second entry established by RRC	CSI-RS resource2
2	Third entry established by RRC	CSI-RS resource3
3	Fourth entry established by RRC	CSI-RS resource4
4	Fiveth entry established by RRC	CSI-RS resource5
5	Sixth entry established by RRC	CSI-RS resource6
6	Seventh entry established by RRC	CSI-RS resource7
7	Eighth entry established by RRC	CSI-RS resource8

However, using high level signaling, such as RRC, to establish the mapping may not be very efficient and can introduce additional delay. For example, as shown in FIG. 6A, the delay 601 from the time an UE sends its feedback to the time the base station sends a DCI message for beam indication is long. In order to reduce this delay 601, a large mapping can be established via RRC. However, a large mapping may increase overhead of DCI messaging. For example, the mapping can include a total N CSI-RS resources for beam selection. To effectively indicate N resources in the mapping,

bits is required in the DCI message. When N is a very large number (e.g., 256 or more) , such overhead may not be acceptable.

Alternatively, the mapping can be established via DCI message exchange. Table 10 shows an exemplary mapping established via DCI messaging. Examples shown in Table 1-8 can also be established via DCI messaging. As shown in FIG. 6B, the delay 603 between the feedback and the DCI message from the base station is shorter. The overhead of DCI can also be reduced because the index value is associated with the CRI feedback by UE and the number of beams selected by UE are far fewer than the number of total beams available at the base station. For example, different beams are represented by different CSI-RS resources and/or different CSI-RS antenna port. The total number of beams at the base station is 256, which requires 8 bits as index value for beam indication. The number of beams selected by a UE is usually not larger than 8. Therefore, only 3 bits are required to indicate the corresponding beam in index values.

Table 10 An example of mapping established via DCI

Index	Index Meaning	Resource Indicator
0	First entry established by DCI	CSI-RS resource1
1	Second entry established by DCI	CSI-RS resource2
2	Third entry established by DCI	CSI-RS resource5
3	Fourth entry established by DCI	CSI-RS resource7

Handling Transmission Failures

Sometimes, feedback from a UE may not be transmitted successfully to the base station. In those cases, the base station may still need to indicate which beam/antenna port should be used for subsequent transmission. In some embodiments, the base station may want to indicate a beam/antenna port that is different from what is included in the feedback from the UE. Therefore, it is desirable for the base station and the corresponding UE to include a subset of associations between the index values and the indicator of a resource can be established without UE feedback and another subset of associations is established with UE feedback. For example, as shown in Table 11, the subset of associations without UE feedback is established by a predetermined rule and/or established by a message such as high level control message.

In some embodiments, the base station sends information to the UE to indicate whether the mapping can include at least one association between the index value and the indicator in the feedback message.

The subset of associations established without UE feedback allows the base station to fall back on a set of beams/antenna ports when the base station fails to receive feedback from a UE. This subset also allow the base station to make alternative selections beyond what is provided by the UE feedback.

In some embodiments, the subset of associations established without UE feedback can be maintained in one mapping along with other entries with UE feedback, such as shown in Table 11. In some implementations, this subset can also be placed in a separate mapping. The subset of the index value indicative of the associations established by RRC and/or UE feedback message can be configured by a control signal. For example the control signal informs that the index set of {0～4} is for the associations established by RRC as shown in Table 11.

Table 11 An example of mapping including default entries

Index	Index Meaning	Indicator
0	First entry established by RRC	CSI-RS resource1
1	Second entry established by RRC	CSI-RS resource2
2	Third entry established by RRC	CSI-RS resource5

3	Fourth entry established by RRC	CSI-RS resource7
4	First CRI included in UE feedback	CSI-RS resource3
5	Second CRI included in UE feedback	CSI-RS resource4-6
6	Third CRI included in UE feedback	CSI-RS resource6
7	Reserved	Reserved

Updating the Mapping

When a base station and a corresponding UE exchange feedback and beam indication messages, it is important for them to update the mapping based on information included in the messages. In some cases, the information included in the feedback message may be time-sensitive, thus it is desirable to keep only relevant information from recent feedback messages, thereby reducing the amount of information stored in the mapping.

The mapping (s) can be updated based on the meaning (s) of the index values. For example, in some embodiments, the base station and the UE can simply update the mapping based on time information. The mapping can be updated in a “first-in-first-out” manner. Tables 12-A to 12-C show an example of updating the mapping based on receiving time of the indictors. Table 12-A shows an example of mapping stored by the base station and the corresponding UE at time slot k+3. The mapping is limited to four entries so that the base station can indicate which beam/antenna port to use with two bits.

Table 12-A An example of mapping at time slot k+3

Index	Index Meaning	Indicator
0	CRI received at latest slot (e.g., slot k+3)	CSI-RS resource1
1	CRI received at the second last slot (e.g., slot k+2)	CSI-RS resource2
2	CRI received at the third last slot (e.g., slot k+1)	CSI-RS resource5
3	CRI received at the fourth last slot (e.g., slot k)	CSI-RS resource7

Table 12-B shows an updated table at time slot k+4. The base station receives a new feedback at slot k+4 that includes CSI-RS resource 6. The base station replaces the oldest entry at index 0 (CSI-RS resource1) with CSI-RS resource 6 included in the most recent feedback and push the other CRI stored in the mapping as shown in Table 12-B.

Table 12-B An example of mapping at time slot k+4

Index	Index Meaning	Indicator
0	CRI received at latest slot (e.g., slot k+4)	CSI-RS resource6
1	CRI received at the second last slot (e.g., slot k+3)	CSI-RS resource1
2	CRI received at the third last slot (e.g., slot k+2)	CSI-RS resource2

3

CRI received at the fourth last slot (e.g., slot k+1)

CSI-RS resource5

Alternatively, the entries can also be rearranged, such as shown in Table 12-C, so that the index values correspond to a time order of when the feedback messages are received. In some cases, the base station can check the existing indicators to see if the indicator included in the feedback message has been added to its mapping. If so, the base station may skip updating the mapping.

Table 12-C Another example of mapping at time slot k+4

Index	Index Meaning	Indicator
0	CRI received at slot k+1	CSI-RS resource1
1	CRI received at slot k+2	CSI-RS resource2
2	CRI received at slot k+3	CSI-RS resource3
3	CRI received at slot k+4	CSI-RS resource6

In some embodiments, the base station and the UE can update the mapping based on report settings included in the feedback. Tables 13-A to 13-B show an example of updating the mapping based on report settings. Table 13-A shows an example of mapping stored by the base station and the corresponding UE at time slot k+3. The mapping is limited to four entries, each entry corresponding to a different report setting.

Table 13-A An example of mapping at time slot k+3

Table 13-B shows an updated table at time slot k+4. The base station receives a new feedback for report setting 2 that includes an resource indicator CSI-RS resource3. The base station replaces the original entry for report setting 2 at index 1 (CSI-RS resource 2) with CSI-RS resource 6 included in the most recent feedback.

Table 13-B An example of mapping at time slot k+4

Index	Index Meaning	Resource Indicator
0	CRI for report Setting 1	CSI-RS resource1
1	CRI for report Setting 2	CSI-RS resource3
2	CRI for report Setting 3	CSI-RS resource5
3	CRI for report Setting 4	CSI-RS resource7

It is also important that the mapping stored by the base station is identical to the mapping stored by the UE to ensure correctness of the beam indication. Synchronization of the mappings can be achieved by the base station sending an acknowledgement to the UE to confirm the receipt of a feedback message. For example, a UE sends a feedback message to a base station as a response to a reference signal. After the base station receives the feedback message successfully, it updates its own mapping and sends an acknowledgement (e.g., ACK) to the UE. The acknowledgement can be sent separately or together with the beam indication message. After the UE receives the acknowledgement, it knows that the base station has successfully receives its feedback message and updated the mapping accordingly. The UE can proceed to update its own mapping using the same set of rules and criteria used by the base station. If the feedback message fails to transmit successfully, the base station also sends a message (e.g., NACK) to indicate the transmission failure. The mappings at the base station and the UE remain the same.

Alternatively, a UE can update its mapping before it sends the feedback message to the base station, using the same set of rules and criteria that is used by the base station. However, if the feedback message fails to transmit successfully to the base station, the base station can have a different mapping from the mapping stored on the UE. In order to ensure that the base station and the UE have the same mapping for beam indication, a two-step updating process can be adopted at the UE. For example, as shown in Table 14-A, after receiving one or more reference signals from the base station, the UE includes CSI-RS resource8 in its feedback message as the resource indicator for report setting 1. The base station and the UE add CSI-RS resource8 to a reserved entry for the latest feedback as step one of the two-step updating process, instead of updating entry 4 directly for report setting 1 in its mapping.

Table 14-A An example of mapping at a UE prior to sending the feedback

Index	Index Meaning	Resource Indicator
0	First entry established by RRC	CSI-RS resource1
1	Second entry established by RRC	CSI-RS resource2
2	Third entry established by RRC	CSI-RS resource5
3	Fourth entry established by RRC	CSI-RS resource7
4	CRI for report Setting 1	CSI-RS resource3
5	CRI for report Setting 2	CSI-RS resource4
6	CRI for report Setting 3	CSI-RS resource6
7	Reserved (latest change)	CSI-RS resource8

If the feedback message is transmitted successfully to the base station, the base station can send an acknowledgment to confirm the receipt of the feedback message. The acknowledgement can be sent separately, or be included in the beam indication message. For example, the base station uses an additional bit (set to “1” ) to acknowledge the receipt of the feedback message in the beam indication message. When the UE sees that the base station has received the feedback successfully upon receiving the acknowledgment, it updates the mapping again as the step two of the two-step updating process to replace the entry for report setting 1 with the new CRI, and clear the entry from the reserved entry. Table 14-B shows an example of mapping at the UE after it receives the acknowledgement.

Table 14-B shows an example of mapping at the UE after it receives the acknowledgement.

Index	Index Meaning	Resource Indicator
0	First entry established by RRC	CSI-RS resource1
1	Second entry established by RRC	CSI-RS resource2
2	Third entry established by RRC	CSI-RS resource5
3	Fourth entry established by RRC	CSI-RS resource7
4	CRI for report Setting 1	CSI-RS resource8
5	CRI for report Setting 2	CSI-RS resource4
6	CRI for report Setting 3	CSI-RS resource6
7	Reserved

If the base station does not receive the feedback successfully, it is not aware of the new CRI. In its next beam indication message (e.g., DCI message) , the bit to acknowledge the receipt of the feedback is set to “0” . The UE now understands, upon receiving the beam indication message, that its feedback was not properly received. It may choose to keep CSI-RS resource8 in the reserved entry and resend the same feedback. It may also choose to clear the reserved entry, and send a different feedback message.

Alternatively, the base station can use the index for the reserved entry to acknowledge the receipt of the feedback without using an additional bit. For example, the base station can include “111” (decimal 7) in its beam indication message. The value of “111” has two meanings. The first meaning is to instruct the UE to receive the DMRS and data using the corresponding CSI-RS resource 8. The second meaning is that the base station has received the latest feedback and updated the mapping accordingly. After receiving the message, the UE understands that the new feedback has been received by the base station. The UE can proceed to the second step of the two-step updating process.

In another example, the base station can implicitly inform UE whether it receive the feedback successfully. For example, the base station and the UE maintain a mapping as shown in Table14-C. A different mapping, as shown in Table 14-D, can be used after the UE send a feedback message including an indicator for report setting 1. The base station can instructs the UE to use the mapping shown in Table 14-D. By instructing so, the base station implicitly informs the UE that the feedback message has been successfully received. The UE now updates the Table 14-C with Table 14-D after receiving this implicit confirmation. Otherwise the UE keeps the current mapping (e.g., Table 14-C) without any changes. In a word, the UE updates the mapping with its feedback message when it receives a response from base station in indicate that the feedback message is transmitted successfully to the base station. Otherwise the UE does not the mapping with its feedback message.

Table 14-C An example of mapping at a UE prior to sending the feedback

Index	Index Meaning	Indicator
0	First entry established by RRC	CSI-RS resource1
1	Second entry established by RRC	CSI-RS resource2
2	Third entry established by RRC	CSI-RS resource5
3	Fourth entry established by RRC	CSI-RS resource7
4	CRI for report Setting 1 (prior to update)	CSI-RS resource3
5	CRI for report Setting 2	CSI-RS resource4
6	CRI for report Setting 3	CSI-RS resource6
7	Reserved	Reserved

Table 14-D An example of mapping at a UE prior to sending the feedback

Index	Index Meaning	Indicator
0	First entry established by RRC	CSI-RS resource1
1	Second entry established by RRC	CSI-RS resource2
2	Third entry established by RRC	CSI-RS resource5
3	Fourth entry established by RRC	CSI-RS resource7
4	CRI for report Setting 1 (post update)	CSI-RS resource8
5	CRI for report Setting 2	CSI-RS resource4
6	CRI for report Setting 3	CSI-RS resource6
7	Reserved	Reserved

It is therefore evident that a method to facilitate wireless communication is disclosed. As shown in FIG. 7, the method 700 includes, at 702, storing associations between multiple values and multiple indicators in a mapping, wherein each association includes a value associated with one or more indicators； at 704, transmitting or receiving a feedback message from a wireless communication node, wherein the message includes one or more indicators； at 706, selecting an association from the mapping based on the feedback message； and, at 708, updating the one or more indicators in the association with the one or more indicators in the feedback message.

In some embodiments , the UE and/or the base station can update the mapping with the indicators in the feedback message only when the feedback message is triggered by a control signal. In some embodiments, the UE sends ACK/NACK in response to the control signal. To the base station and the UE having different mappings, which can be caused by transmission failures of the control signal, the control signal can be a high-level signal such as RRC or MAC-CE signal rather than a DCI signal.

In some embodiments, the UE and or the base station can update the mapping with the information in the PRACH sending from the UE.

Time Information for Changing Reference Signal

In some embodiments, the beam associated with the reference signal may change in a periodic or semi-persistent manner. For example, as shown in FIG. 8A, in time window 1 of CSI-RS (801) , beam 1 (802) is used. The beam associated with the CSI-RS changes to beam 2 (804) in time window 2 of CSI-RS (803) . The beam changes again to beam 3 (806) in time window 3 of CSI-RS (805) . Because the beam associated with reference signal changes over time, the feedback from the UE becomes time-sensitive. It is thus desirable for the base station to specify the relevant timing information of the reference signal (or its corresponding indicator) when it uses the reference signal to inform the beam of DMRS/CSI-RS/SRS.

The base station can establish a quasi-co-location relationship between the CSI-RS reference signal and DMRS/CSI-RS/SRS. For example, there is an QCL assumption between the reference signal corresponds to the CSI-RS port1 and the DMRS. If the base station uses the CSI-RS port 1 without any additional timing information to indicator the beam of DMRS, the beam of DMRS will be fuzzy because the beams at different time windows of the CSI-RS port 1 are different. Therefore, the base station may use a CRI with time window information to inform the beam of DMRS. For example, as shown in Table 15, if the base station includes index value “0” in its message (s) , the UE uses the CSI-RS port 1 in time window 4 to receive the DMRS and the PDSCH. For example the UE should use the same receiving beam used by receive the CSI- RS port1 in time window 4 to receive the DMRS and the PDSCH.

Table 15 An example of mapping based on time windows

Index	Index Meaning
0	Association between CSI-RS port1 received at time window 4 and DMRS of PDSCH
1	Association between CSI-RS port1 received at time window 3 and DMRS of PDSCH
2	Association between CSI-RS port1 received at time window 2 and DMRS of PDSCH
3	Association between CSI-RS port1 received at time window 1 and DMRS of PDSCH

In the example shown in Table 15, the UE may get the large-scale properties of DMRS and data derived from the large-scale properties of CSI-RS port1 of time window 4. The large-scale properties include one or more following properties: delay spread, Doppler spread, Doppler shift, average gain, and average delay. The UE can also get spatial Rx parameters of DMRS based on the spatial Rx parameters of CSI-RS port1 of time window 4 wherein the spatial Rx parameters include one or more of parameters: AoA, Dominant AoA, average AoA, Power Angular Spectrum (PAS) of AoA, average AoD, PAS of AoD, transmit/receive channel correlation, transmit/receive beamforming, spatial channel correlation etc. The UE can further get spatial Rx spatial filter of DMRS based on the Rx spatial filter of CSI-RS of time window 4.

The information of the time window of a CSI-RS port can be configured when the base station configures a CSI-RS resource/CSI-RS resource set/CSI-RS resource setting which includes the CSI-RS port. The information of the time window of a CSI-RS port can also be configured when the base station configures a measurement setting which includes a link between a report setting and a CSI-RS resource setting including the CSI-RS port. The information of the time window of a CSI-RS port can also be configured when the base station configures a link between a report setting and a CSI-RS resource setting including the CSI-RS port. The information of the time window of a CSI-RS port can also be configured when the base station configures a report/report setting which is associated with a CSI-RS resource setting including the CSI-RS port. The information of the time window of a CSI-RS port can include one or more following parameters: the time window boundaries, number of OFDM symbols in a time window, and the number of CSI-RS periods in a time window. In particular, the number of the OFDM symbol can further include the number of OFDM symbol with different subcarrier spacing.

The time window of a CSI-RS port can be determined implicitly by the parameters of the measurement restriction. For example, the measurement restriction can limit the UE to measure the channel base on the CSI-RS (or other reference signal) of one particular time window and report the channel state information obtained on the channel in that time window.

In some embodiments, the time window boundaries can be determined based an instant of a report or report setting. For example, the UE transmits channel state information for a report setting every 10 slots. For each instance of a report, there is a corresponding time window, and the channel state information can be obtained from the CSI-RS in the time window. In some embodiments, the time window boundaries can be determined based on an instant of a channel measurement. For example, the UE measures the channel every 5 slots, for each slot in which UE measures the channel, there is a corresponding time window (for example, from the last slot in which UE measures the channel till the current slot, the duration of corresponding time window is therefore 5 slots) , and the channel state information can be obtained from the CSI-RS in the time window.

In some embodiments, the base station can establish, in each of the time windows, boundaries of a CSI-RS time window by a report setting or a port associated with the CSI-RS. For example, as shown in FIG. 8B, an association can be established between window 1 of a CSI-RS and report setting 1 (811) . Similarly, associations can be established between window 2 of the CSI-RS and report setting 2 (812) , as well as between window 3 of the CSI-RS and report setting 3 (813) . In some embodiments, boundaries of the time window are determined based on report instants in a report setting which is associated with CSI-RS reference signal. Similarly, in some embodiments, the base station can establish, in each of the time windows, boundaries of a CSI-RS time window based on one or more of the following parameters associated with the CSI-RS: for example, a measurement setting , ameasurement , or a link.

In some embodiments, the time window is included in a set of time windows. The set of time windows can be ordered by an end time of each of the time windows in the set of the time windows. In some implementations, the set of time windows includes a first time window positioned closest to a transmission time of the second reference signal in a time-domain. The time interval between an end time of the first window and the transmission time of the second reference signal may be larger than a predetermined threshold. The set of time windows also includes a second time window positioned farthest from a transmission time of the second reference signal in a time-domain. The time interval between a start time of the second time window and the transmission time of the second reference signal may be smaller than another predetermined threshold to ensure a proper distance with the first reference signal (e.g., DMRS) .

FIG. 9 shows an example of a wireless communication system where techniques in accordance with one or more embodiments of the present technology can be applied. A wireless communication system 700 can include one or more base stations (BSs) 905a, 905b, one or

more wireless devices

910a, 910b, 910c, 910d, and an access network 925. A

base station

905a, 905b can provide wireless service to

wireless devices

910a, 910b, 910c and 910d in one or more wireless sectors. In some implementations, a

base station

905a, 905b includes directional antennas to produce two or more directional beams to provide wireless coverage in different sectors.

The access network 925 can communicate with one or

more base stations

905a, 905b. In some implementations, the access network 925 includes one or

more base stations

905a, 905b. In some implementations, the access network 925 is in communication with a core network (not shown in FIG. 9) that provides connectivity with other wireless communication systems and wired communication systems. The core network may include one or more service subscription databases to store information related to the subscribed

wireless devices

910a, 910b, 910c and 910d. A first base station 905a can provide wireless service based on a first radio access technology, whereas a second base station 905b can provide wireless service based on a second radio access technology. The

base stations

905a and 905b may be co-located or may be separately installed in the field according to the deployment scenario. The access network 925 can support multiple different radio access technologies.

In some implementations, a wireless communication system can include multiple networks using different wireless technologies. A dual-mode or multi-mode wireless device includes two or more wireless technologies that could be used to connect to different wireless networks.

FIG. 10 is a block diagram representation of a portion of a radio station. A radio station 1005 such as a base station or a wireless device (or UE) can include processor electronics 1010 such as a microprocessor that implements one or more of the wireless techniques presented in this document. The radio station 1005 can include transceiver electronics 1015 to send and/or receive wireless signals over one or more communication interfaces such as antenna 1020. The radio station 1005 can include other communication interfaces for transmitting and receiving data. Radio station 1005 can include one or more memories (not explicitly shown) configured to store information such as data and/or instructions. In some implementations, the processor electronics 1010 can include at least a portion of the transceiver electronics 1015. In some embodiments, at least some of the disclosed techniques, modules or functions are implemented using the radio station 1005.

FIG. 11 is a flowchart representation of a wireless communication method 1100. The method 1100 includes, at 1102, receiving a feedback message including one or more indicators from a wireless communication node, wherein each of the one or more indicators indicates a resource corresponding to a reference signal； and, at 1104, transmitting a control message that includes a value indicative of at least one indicator selected from the one or more indicators to the wireless communication node. In some embodiments, the resource includes a beam for transmission with the wireless communication node.

In some embodiments, the value is indicative of a parameter set. The parameter set includes one or more parameters for the at least one indicator. The one or more parameters include timing information, a parameter of reporting setting, a parameter of a resource setting, a parameter of a resource set, a channel or signal quality of the resource, and an ordinal number of the at least one indicator in a set of indicators from the wireless communication node.

In some embodiments, the value is associated with one or more properties of the reference signal, the one or more properties including: timing information, a reporting setting, a link, a measurement setting, a resource setting, a resource set, a resource, a channel quality, a signal quality, and a channel condition. In some embodiments, the value is associated with an order of the one or more indicators in the feedback message.

In some embodiments, the method further includes obtaining an association between the value and the at least one indicator selected from the one or more indicators in a mapping, wherein the mapping includes a predetermined set of associations between values and indicators based on a message. In some implementations, the method further includes establishing a subset of the predetermined set of associations using high-level-signaling.

In some embodiments, the method further includes updating the mapping based on a comparison of the one or more indicators in the feedback message and the indicators stored in the mapping. In some implementations, the method also includes updating the mapping with at least one indicator from the one or more indicators in the feedback message when transmits a ACK confirm message to the wireless communication node for the feedback message. In some embodiments, the method also includes updating the mapping based on a determination that the feedback message satisfies a predetermined set of criteria.

In some embodiments, the value is also indicative of an association between another reference signal and the reference signal indicated by the indicator.

FIG. 12 is another flowchart representation of a wireless communication method 1200. The method 1200 includes, at 1204, transmitting a feedback message including one or more indicators to a wireless communication node, wherein each of the one or more indicators indicates a resource corresponding to a reference signal； at 1206, receiving a control message that includes a value indicative of at least one indicator selected from the one or more indicators； and, at 1206, performing transmission using the resource indicated by the indicator based on the value. In some embodiments, the resource includes a beam for performing the transmission.

In some embodiments, the value is indicative of a parameter set. The parameter set includes one or more parameters for the at least one indicator. The one or more parameters include timing information, a parameter of reporting setting, a parameter of a resource setting, a parameter of a resource set index, a channel or signal quality of the resource, and an ordinal number of the at least one indicator in a set of indicators from the wireless communication node.

FIG. 13 is another flowchart representation of a wireless communication method 1300. The method 1300 includes, at 1302, receiving a feedback message based on a reference signal from a wireless communication node, the feedback message including channel state information of a communication link； and, at 1304, transmitting a message to the wireless communication node to indicate a receipt status of the feedback message.

In some embodiments, the transmitting of the message is based on a determination that the channel state information satisfies a predetermined set of criteria. In some embodiments, the predetermined set of criteria includes determining that the channel state information includes one or more indicators, the one or more indicators including a reference signal resource indicator, an antenna port indicator, a resource setting indicator, and a relative power indicator. In some implementations, the predetermined set of criteria includes determining that the feedback message is transmitted in a predetermined window. In some embodiments, the feedback message includes one or more indicators, each of the one or more indicators indicating a beam corresponding to the reference signal for data transmission.

FIG. 14 is another flowchart representation of a wireless communication method 1400. The method 1400 includes, at 1402, transmitting a feedback message based on a reference signal to a wireless communication code, the feedback message including channel state information of a communication link； and, at 1404, receiving a message from the wireless communication node, the message indicative of a receipt status of the feedback message. In some embodiments, the channel state information satisfies a predetermined set of criteria. In some embodiments, the feedback message includes one or more indicators, each of the one or more indicators indicating a beam corresponding to the reference signal for data transmission.

FIG. 15 is another flowchart representation of a wireless communication method 1500. The method 1500 includes, at 1502, establishing an association between a first reference signal in a time window and a second reference signal； and, at 1504, transmitting or receiving the second reference signal based on the association. In some embodiments, the association is a Quasi-Co-location relation between the first reference signal in the time window and the second reference signal. In some implementations, the receiver spatial filter of the first reference signal in a time window is same the receiver spatial filter of the second reference signal.

In some embodiments, properties of the time window are configured in at least one parameter set of a plurality of parameter sets. The plurality of parameter sets includes a parameter set of a measurement setting associated with the first reference signal, a parameter set of a link associated with the first reference signal, a parameter set of a report setting associated with the first reference signal, a parameter set of a resource setting including the first reference signal, a parameter set of a resource set including the first reference signal, and a parameter set of a resource including the first reference signal.

In some embodiments, the time window is configured based on one or more properties associated with the first reference signal, the one or more properties including a measurement setting, a link, a report setting, a report, a resource setting, a resource set, and a resource. The time window can also be determined based on one or more properties associated with the first reference signal, the one or more properties including a measurement setting, a link, and a report setting. In some implementations, the method further includes determining boundaries of the time window based on an instant of a report setting associated with the first reference signal.

In some embodiments, the time window is included in a set of time windows. In some implementations, the set of time windows includes a first time window positioned at a first distance in time domain from a transmission time of the second reference signal. A time interval between an end time of the first time window and the transmission or receipt time of the second reference signal is larger than a predetermined threshold and the first distance shorter than distances of other time windows in the set of time windows from the transmission time of the second reference signal. The set of time windows also includes a second time window positioned at a second distance in time domain from a transmission time of the second reference signal in time-domain. A time interval between a start time of the second time window and the transmission or receipt time of the second reference signal is smaller than a predetermined threshold and the second distance longer than distances of other time windows in the set of time windows from the transmission time of the second reference signal.

In some embodiments, the set of time windows includes a predetermined number of time windows and an index of each of the time windows is determined by a start time or an end time of the time window.

In some embodiments, the set of time windows includes a first time window positioned closest to a transmission time of the second reference signal in time-domain and a second time window positioned furthest from the transmission time of the second reference signal in time-domain.

Some of the embodiments described herein are described in the general context of methods or processes, which may be implemented in one embodiment by a computer program product, embodied in a computer-readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM) , Random Access Memory (RAM) , compact discs (CDs) , digital versatile discs (DVD) , etc. Therefore, the computer-readable media can include a non-transitory storage media. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-or processor-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

Some of the disclosed embodiments can be implemented as devices or modules using hardware circuits, software, or combinations thereof. For example, a hardware circuit implementation can include discrete analog and/or digital components that are, for example, integrated as part of a printed circuit board. Alternatively, or additionally, the disclosed components or modules can be implemented as an Application Specific Integrated Circuit (ASIC) and/or as a Field Programmable Gate Array (FPGA) device. Some implementations may additionally or alternatively include a digital signal processor (DSP) that is a specialized microprocessor with an architecture optimized for the operational needs of digital signal processing associated with the disclosed functionalities of this application. Similarly, the various components or sub-components within each module may be implemented in software, hardware or firmware. The connectivity between the modules and/or components within the modules may be provided using any one of the connectivity methods and media that is known in the art, including, but not limited to, communications over the Internet, wired, or wireless networks using the appropriate protocols.

While this patent document contains many specifics, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this patent document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.

Only a few implementations and examples are described and other implementations, enhancements and variations can be made based on what is described and illustrated in this patent document.

Claims

A method of wireless communication, comprising:

receiving a feedback message including one or more indicators from a wireless communication node, wherein each of the one or more indicators indicates a resource corresponding to a reference signal； and

transmitting a control message that includes a value indicative of at least one indicator selected from the one or more indicators to the wireless communication node.
The method of claim 1, wherein the value is indicative of a parameter set, the parameter set including one or more parameters for the at least one indicator.
The method of claim 2, wherein the one or more parameters include timing information, a parameter of reporting setting, a parameter of a resource setting, a parameter of a resource set, a channel or signal quality of the resource, and an ordinal number of the at least one indicator in a set of indicators from the wireless communication node.
The method of claim 1, further comprising:

obtaining an association between the value and the at least one indicator selected from the one or more indicators in a mapping, wherein the mapping includes a predetermined set of associations between values and indicators based on a message.
The method of claim 2, further comprising establishing a subset of the predetermined set of associations using high-level-signaling.
The method of claim 2, further comprising:

updating the mapping based on a comparison of the one or more indicators in the feedback message and the indicators stored in the mapping.
The method of claim 1, wherein the value is indicative of an association between another reference signal and the reference signal indicated by the indicator.
A method of wireless communication, comprising:

transmitting a feedback message including one or more indicators to a wireless communication node, wherein each of the one or more indicators indicates a resource corresponding to a reference signal；

receiving a control message that includes a value indicative of at least one indicator selected from the one or more indicators； and

performing transmission using the resource indicated by the indicator based on the value.
The method of claim 8, wherein the value is indicative of a parameter set, the parameter set including one or more parameters for the at least one indicator.
The method of claim 9, wherein the one or more parameters include timing information, a parameter of reporting setting, a parameter of a resource setting, a parameter of a resource set index, a channel or signal quality of the resource, and an ordinal number of the at least one indicator in a set of indicators from the wireless communication node.
The method of claim 8, further comprising:

obtaining an association between the value and the at least one indicator selected from the one or more indicators in a mapping, wherein the mapping includes a predetermined set of associations between values and indicators based on a message.
The method of claim 11, further comprising establishing a subset of the predetermined set of associations using high-level-signaling.
The method of claim 11, further comprising:

updating the mapping based on a comparison of the one or more indicators in the feedback message and the indicators stored in the mapping.
The method of claim 8, the value is indicative of an association between another reference signal and the reference signal indicated by the indicator.
A method of wireless communication, comprising:

receiving a feedback message based on a reference signal from a wireless communication node, the feedback message including channel state information of a communication link； and

transmitting a message to the wireless communication node to indicate a receipt status of the feedback message.
The method of claim 15, wherein the transmitting of the message is based on a determination that the channel state information satisfies a predetermined set of criteria.
The method of claim 16, wherein the predetermined set of criteria includes determining that the channel state information includes one or more indicators, the one or more indicators including a reference signal resource indicator, an antenna port indicator, a resource setting indicator, and a relative power indicator.
The method of claim 16, wherein the predetermined set of criteria includes determining that the feedback message is transmitted in a predetermined time window.
A method of wireless communication, comprising:

establishing an association between a first reference signal in a time window and a second reference signal； and

transmitting or receiving the second reference signal based on the association.
The method of claim 19, wherein properties of the time window are configured in at least one parameter set of a plurality of parameter sets, the plurality of parameter sets including a parameter set of a measurement setting associated with the first reference signal, a parameter set of a link associated with the first reference signal, a parameter set of a report setting associated with the first reference signal, a parameter set of a resource setting including the first reference signal, a parameter set of a resource set including the first reference signal, and a parameter set of a resource including the first reference signal.
The method of claim 19, further comprising determining boundaries of the time window based on an instant of a report setting associated with the first reference signal.
The method of claim 20, wherein the time window is included in a set of time windows.
The method of claim 22, wherein the set of time windows includes a first time window positioned at a first distance in time domain from a transmission time of the second reference signal, a time interval between an end time of the first time window and the transmission or receipt time of the second reference signal larger than a predetermined threshold and the first distance shorter than distances of other time windows in the set of time windows from the transmission time of the second reference signal.
The method of claim 22, wherein the set of time windows includes a second time window positioned at a second distance in time domain from a transmission time of the second reference signal in time-domain, a time interval between a start time of the second time window and the transmission or receipt time of the second reference signal smaller than a predetermined threshold and the second distance longer than distances of other time windows in the set of time windows from the transmission time of the second reference signal.
The method of claim 22, wherein the set of time windows includes a predetermined number of time windows, wherein an index of each of the time windows is determined by a start time or an end time of the time window.
The method of claim 19, wherein the association is a quasi-co-location relationship.
A wireless communication device configured to carry out the steps of any one of claims 1 through 26.
A non-transitory computer-readable medium having stored thereon computer executable instructions for carrying out the method of any one of claims 1 through 26.