Transmitting reference signal information

Abstract

A wireless communication method comprises allocating a plurality of transmission resources to a third reference signal according to a subcarrier index of a first reference signal and a predefined order of a third, first and second reference signals; and using the third reference signal according to the plurality of transmission resources. The plurality of transmission resources comprises a plurality of subcarriers distributed on one or more orthogonal frequency division multiplexing symbols.

Description

Technical Field

[0001] This document relates to systems, devices, and techniques for wireless communications. Background Art

[0002] Efforts are currently underway to define the next generation of wireless communication networks to provide greater deployment flexibility, support for a wide range of devices and services, and different techniques for efficient use of bandwidth. To better utilize bandwidth, techniques such as utilizing multiple antennas for transmission and / or reception are also being used. Summary of the invention

[0003] Techniques for communicating and using timing information associated with wireless communication networks are described herein.

[0004] In one exemplary aspect, a wireless communication method is disclosed. The method includes allocating a plurality of transmission resources to a first reference signal based on a subcarrier index of the first reference signal and a predefined order of the third reference signal, the first reference signal, and the second reference signal. The method also includes using the third reference signal based on a plurality of transmission resources. The plurality of transmission resources include a plurality of subcarriers distributed on one or more orthogonal frequency division multiplexing symbols.

[0005] In another exemplary aspect, a wireless communication method is disclosed, including receiving an indication of the presence of a reference signal for transmission of a wireless system, and obtaining from the indication a usage status of code division multiplexing in a time domain in transmission of other signals in the wireless system.

[0006] In another exemplary aspect, the various techniques described herein may be implemented as processor-executable code and stored on a computer-readable program medium.

[0007] The details of one or more implementations are set forth in the accompanying appendices, drawings, and the following description. Other features will be apparent from the embodiments and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 An example or transmission resource allocation in a resource allocation grid is shown.

[0009] Figure 2 Another example or transmission resource allocation in a resource allocation grid is shown.

[0010] Figure 3 Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0011] Figure 4 Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0012] Figure 5Another example or transmission resource allocation in a resource allocation grid is shown.

[0013] Figure 6 Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0014] Figure 7 Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0015] Fig. 8A Another example or transmission resource allocation in a resource allocation grid is shown.

[0016] Figure 8B Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0017] Figure 8C Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0018] Fig.8D Another example or transmission resource allocation in a resource allocation grid is shown.

[0019] Fig. 8E Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0020] Figure 8F Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0021] Figure 8G Another example or transmission resource allocation in a resource allocation grid is shown.

[0022] Figure 8H An example of a control channel resource set is shown.

[0023] Figure 8I Another example of a control channel resource set is shown.

[0024] Fig. 9 Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0025] Fig.10 Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0026] Fig.11 Another example or transmission resource allocation in a resource allocation grid is shown.

[0027] Fig.12 Yet another example or transmission resource allocation in a resource allocation grid is shown.

[0028] Fig.13A flow chart illustrating one example of a process for wireless communication.

[0029] Fig.14 A flow chart illustrating another example of a process for wireless communication is shown.

[0030] Fig.15 A flow chart illustrating yet another example of a process for wireless communication is shown.

[0031] Fig.16 One example of a wireless communication device for implementing the techniques described herein is shown.

[0032] Fig.17 An exemplary wireless communication network is shown that may embody the techniques disclosed herein.

[0033] Like reference numerals in the various drawings denote the same elements. DETAILED DESCRIPTION

[0034] Today, the demand for wireless bandwidth is increasing day by day. With the proliferation and development of wireless devices such as smartphones and tablets, wireless networks are looking for new ways to provide greater bandwidth for two-way communication between wireless devices and the network.

[0035] In order to maintain the performance of wireless networks and be able to provide as much bandwidth as possible to wireless devices, modern wireless systems use certain reference signals. These reference signals are usually transmitted at a known time and frequency with characteristics known to the receiver. Upon receiving the reference signal transmission, the receiver can perform operations such as comparing the received signal to the expected "ideal" reference signal or calculating the quality of the reference signal. The wireless network can then use these measurements to change certain operating parameters, such as bandwidth allocation, frequency adjustments, etc.

[0036] Faced with the challenge of providing greater bandwidth to more wireless devices for upcoming wireless networks, the wireless industry is looking for ways to improve the efficiency of wireless networks. For example, next-generation wireless networks such as 5G networks should be able to provide more bits per second per unit area per Hertz than current systems. In order to achieve higher efficiency and maintain network performance under a variety of operating conditions, next-generation wireless networks are considering new reference signals and / or new methods of using traditional reference signals.

[0037] However, the design of new reference signals and the transmission times or subcarriers allocated to these reference signals should enable the new reference signals to be transmitted in wireless networks using resources that make the reference signals useful while not creating backward compatibility issues with legacy receivers.

[0038] Techniques that can be used to implement such new reference signals are described herein. Some embodiments are described herein with reference to a new reference signal called a "Phase Tracking Reference Signal (PT-RS)", which uses and coexists with traditional reference signals such as a Demodulation Reference Signal (DMRS), a Channel State Information Reference Signal (CSI-RS), and the like. However, the techniques are applicable to the general challenge of introducing new reference signals in existing wireless systems. In addition, although these techniques are described in systems based on Orthogonal Frequency Domain Modulation (OFDM), such as the 5G system being considered by the Third Generation Partnership Project (3GPP) group, these techniques may also be extended to other communication networks. Further, in this article, section headings are used to improve the readability of the disclosed techniques and do not limit the scope of the disclosed techniques in any way. The various figures used herein to highlight the allocation of transmission resources show a two-dimensional resource grid, in which the horizontal axis represents the time or symbol used for transmission and the vertical axis represents the subcarrier (frequency), as is well known in the 3GPP literature.

[0039] In high-frequency environments, phase noise causes performance loss in communication systems. In high-speed mobile environments, high-speed Doppler shift may have an adverse effect on bandwidth efficiency, but the presence of PT-RS can effectively compensate for phase noise and high-speed Doppler shift. However, PT-RS also increases overhead, so an effective trade-off should be made between overhead and compensation performance improvement. Consideration should be given to how to configure the PT-RS time domain and frequency domain positions, including how to determine the PT-RS frequency position using the DM-RS frequency position, how to compensate for the phase noise of OFDM symbols without PT-RS when PT-RS overlaps with other reference signals such as CSI-RS or high-speed Doppler shift CSI-RS, and how to control overhead without causing a large amount of compensation performance loss.

[0040] As agreed in the recent 3GPP RAN1 meeting, the PTRS port and the associated DMRS port are transmitted on the same subcarrier. Figure 1 As shown, PTRS port 1 is associated with pre-DMRS port 1, and the same is true for PTRS port 2. The PTRS mode can be configured in multiple densities in the time domain. Figure 1 The full time domain density is shown.

[0041] If data is transmitted in a manner that is not sensitive to delay and is not sensitive to phase noise or high Doppler shift, additional DMRS are configured to obtain better channel estimation. Figure 2 As shown, PTRS is transmitted in the first and second subcarriers, which overlap with the additional DMRS port 1 and port 2, so DMRS information is only transmitted on OFDM symbol 9 of subcarrier 1 and subcarrier 2.

[0042] The same DMRS ports in the pre-DMRS and the additional DMRS may be transmitted on different subcarriers; this can reduce the impact of high-speed Doppler shift compared to all DMRS ports being configured as pre-DMRS.

[0043] Figure 3 An example is shown in which the same port of the pre-DMRS and the additional DMRS do not occupy the same subcarrier. Under the same overhead condition, the influence of Doppler frequency shift on system performance is relatively good.

[0044] like Figure 4 As shown in Figure 1, CSI-RS and PTRS are transmitted on the same subcarrier in the frequency domain, and the last two OFDM symbols are transmitted in the time domain. PTRS cannot be applied on these overlapping REs, which may have a great impact on phase compensation due to severe phase noise or high-speed Doppler frequency shift.

[0045] Therefore, in some embodiments, one DMRS port occupies multiple subcarriers in one physical resource block (PRB), and PTRS is configured in one or more of these subcarriers. When PTRS and CSI-RS overlap on a subcarrier, some instances may select other subcarriers to send PTRS, and the subcarrier may be a subcarrier that sends DMRS with different symbols. In addition, some instances may allocate transmission resources to PTRS by considering other reference signals such as CSI-RS.

[0046] Case 1: When there is non-zero power and / or zero power CSI-RS (in a PRB)

[0047] Scenario 1:

[0048] As is known to all, DMRS can be configured as only pre-DMRS or pre-DMRS and additional DMRS. Taking pre-DMRS and additional DMRS as an example, Figure 7 As shown, DMRS port 1 is transmitted in four subcarriers, i.e., subcarriers #1 and #7 are used as pre-DMRS, #5 and #11 are used as additional DMRS, and PTRS is transmitted on the lowest index subcarrier associated with DMRS by default, e.g. Figure 7 However, CSI-RS is also transmitted on subcarrier #1 of the 13th and 14th OFDM symbols, which may cause adverse effects on PTRS and CSI-RS. If PTRS cannot be sent on these OFDM symbols, phase noise or high-speed Doppler shift may not be compensated, and a new subcarrier can be reselected to send PTRS based on the subcarrier index displacement configured to send the relevant DMRS.

[0049] 1) If Figure 5As shown, in some embodiments, there is only pre-loaded DMRS. In this case, for PT-RS transmission resources, some embodiments may use an increased subcarrier index configured as DMRS port 1, i.e., the frequency position of PTRS port 1 is changed from subcarrier #1 to subcarrier #5, and if subcarrier #5 is also configured to transmit CSI-RS, then continue to the next subcarrier.

[0050] 2) Configure additional DMRS.

[0051] In this case, the allocation of PT-RS can be explained as follows.

[0052] (a) First, select the subcarrier configured as pre-loaded DMRS port 1. Figure 7 As shown, on subcarrier #1, PTRS may overlap with CSI-RS, and then subcarrier #7 is selected instead. If subcarrier #7 also overlaps with CSI-RS, subcarriers #5 and #11 are selected instead.

[0053] (b) Increase the subcarrier index without considering the pre-DMRS and the additional DMRS. Figure 7 As shown, on subcarrier #1, PTRS overlaps with CSI-RS, and subcarrier #5 is selected next. If subcarrier #5 also overlaps with CSI-RS, the next subcarrier #7 is selected.

[0054] If all subcarriers that can be configured as PTRS overlap with CSI-RS, i.e., subcarriers #1, #5, #7, and #11, then:

[0055] -Select the lowest index subcarrier associated with the DMRS, e.g. Figure 7 Subcarrier #1 in ;

[0056] -Select the next subcarrier that is not configured as DMRS, i.e. Figure 7 Subcarrier #3 in ;

[0057] - Use the frequency density parameter of the PTRS configuration to select the applicable subcarrier. Figure 6 In the example shown, the frequency density of PTRS is configured as PTRS every two PRBs. In PRB #1, all subcarriers configured to send DMRS port 1 are used to send CSI-RS on OFDM symbols #13 and #14. Then the subcarriers in PRB2 can be selected to send PTRS. If the frequency density of PTRS is configured as one PTRS every 4 PRBs, PRB2, PRB3, and PRB4 are candidate PTRS.

[0058] Scenario 2:

[0059] The intersection of the subcarriers of DMRS and CSI-RS is calculated, and the subcarriers configured as DMRS are selected, except for the intersection of DMRS and CSI-RS.

[0060] Solution 3:

[0061] Sets a threshold for the number of REs that can be used to transmit data on a subcarrier in a PRB. If the number of REs used to transmit data on a subcarrier is greater than the threshold, the subcarrier can be configured to transmit PTRS, and vice versa. Fig. 8A As shown, the threshold is set to 10, that is, the number of REs can be used to transmit data. PTRS can overlap with the non-zero power CSI-RS on subcarrier #1 and the zero power CSI-RS on subcarrier #5. The number of REs that can be used to send data is less than the threshold, and the number of REs that can be used to send data on the other two subcarriers is greater than the threshold. Therefore, subcarrier #7 and subcarrier #11 can be configured to send PTRS.

[0062] Case 2:

[0063] If there is only zero-power CSI-RS on the resources sent to one UE, a threshold value for the number of REs or subcarriers that can be used to transmit data on these OFDM symbols should be set, and the threshold value can also be the ratio of the number of resource elements (REs) or subcarriers used to transmit data to zero-power CSI-RS. If the number of REs or subcarriers used to transmit data is greater than the threshold value, PTRS should be transmitted on these OFDM symbols, and vice versa.

[0064] Example 1A

[0065] Based on a predefined order, a port PTRS is mapped to M consecutive subcarriers within N PRBs. Subcarriers that do not carry other RSs (such as CSI-RS) have high priority for PTRS transmission. N and M are equal to or greater than 1.

[0066] Among N PRBs, the PT-RS is mapped to the subcarrier with the lowest or highest index found.

[0067] If there is a first region, the discovered subcarrier is the subcarrier with the lowest or highest index in the first region. The subcarriers in the first region do not carry other RS, such as CSI-RS. At the same time, the discovered subcarrier cannot be a subcarrier that has been occupied by other PTRS ports of the UE. In other words, for a PTRS port of a UE, the first region does not include subcarriers that have been allocated to other PTRS ports of the UE.

[0068] If there is a second region, the discovered subcarrier is the subcarrier with the lowest or highest index in the second region. The subcarriers in the second region do not carry other RS, such as CSI-RS and associated DMRS. At the same time, the discovered subcarrier cannot be a subcarrier that has been occupied by other PTRS ports of the UE. In other words, for one PTRS port of a UE, the second region does not include subcarriers that have been allocated to other PTRS ports of the UE.

[0069] When the first or second region does not exist, the subcarriers allocated for PT-RS transmission are the subcarriers with the lowest or highest index in the third region, where the subcarriers of the third region carry associated DMRS.

[0070] In some embodiments, the second region has a higher priority than the first region. In other words, if the second region exists, the subcarrier allocated to the PT-RS is the subcarrier with the lowest or highest index in the second region, where the subcarrier in the second region does not carry other RS, such as CSI-RS and associated DMRS. However, if the second region does not exist and the first region exists, the subcarrier found is the subcarrier with the lowest or highest index in the first region, where the subcarrier in the first region does not carry other RS, such as CSI-RS. In this case, the PTRS port will be mapped to the subcarrier without carrying the associated DMRS and CSI-RS.

[0071] In some embodiments, under these circumstances, PTRS and DMRS cannot be transmitted simultaneously.

[0072] In these cases, PTRS and CSI-RS should be transmitted simultaneously if the following conditions are met:

[0073] [1] Data can be transmitted within the CSI-RS symbol, or CSI-RS is not used for beam management.

[0074] [2] Either the first or second region exists.

[0075] In these cases, CSI-RS includes zero-power CSI-RS and non-zero-power CSI-RS. CSI-RS can be replaced by other RS, such as SRS.

[0076] like Figure 8B As shown, M=1, N=1 and PTRS port 1 is linked to DMRS port 3. Since subcarrier #1 carries CSI-RS, it has a low priority, and subcarriers #2-#12 have a high priority.

[0077] In this case, since subcarriers #2 to #12 do not carry CSI-RS, the first region exists and includes subcarriers #2-#12, and the found subcarrier is the subcarrier with the lowest index in the first region, i.e., subcarrier #2. The mapping can be done in Figure 8B Found in.

[0078] In another case, since subcarriers #3, #5, #7, #9, #11 carry DMRS and do not carry CSI-RS, the second region exists and includes subcarriers #3, #5, #7, #9, #11. The found (allocated) subcarrier is the subcarrier with the lowest index in the second region, i.e., subcarrier #3. The mapping can be done in Figure 8C Found in.

[0079] When the first and second regions do not exist, the subcarrier found is the subcarrier with the lowest or highest index in the third region. The subcarriers of the third region are the subcarriers carrying the associated DMRS. In this case, the third region includes subcarriers #1, #3, #5, #7, #9, #11. Then, PTRS is mapped to subcarrier #1.

[0080] In some embodiments, the second region has a higher priority than the first region. In other words, if the second region exists, the subcarrier found is the lowest subcarrier in the second region, where the subcarrier in the second region does not carry other RS, such as CSI-RS and associated DMRS. However, if the second region does exist and the first region exists, the subcarrier found is the lowest subcarrier in the first region. If the subcarrier in the first region does not carry other RS, such as CSI-RS. In this case, the PTRS port will be mapped to the subcarrier without the associated DMRS and CSI-RS. The mapping can be in Fig.8D Found in Fig.8D In the example, CSI-RS is mapped to the same subcarrier with DMRS, and the second region does not exist.

[0081] In some embodiments, the lowest subcarrier in a region within N PRBs means that the subcarrier has the lowest number. Fig.8D In the example, if a region contains subcarriers with indices 1, 3, 5, and 7 in 1 PRB, the lowest subcarrier in the region is the subcarrier with index 1.

[0082] In some embodiments, the highest subcarrier in a region means that the subcarrier has the highest number. Fig.8D In the example, if a region includes subcarriers with indices 1, 3, 5, and 7, the highest subcarrier in the region is the subcarrier with index 7.

[0083] Example 1B

[0084] Based on a predefined order, X PTRS ports are mapped to X consecutive subcarriers within N PRBs. N is equal to or greater than 1, and X is equal to or greater than 1. For one UE, one PTRS port is mapped to one subcarrier, and different PTRS ports are mapped to different subcarriers. In addition, the following rules can be used for transmission resource allocation.

[0085] 1) In N PRBs, X PTRS ports are mapped to the discovered subcarriers with the lowest or highest index in the discovered region.

[0086] A) If there is a first region, the found subcarriers are the X subcarriers with the lowest or highest index in the first region, where the first region has at least X subcarriers that do not carry other RSs, such as CSI-RS.

[0087] B) If there is a second region, the found subcarriers are the X subcarriers with the lowest or highest index in the second region, where the second region has at least X subcarriers that do not carry other RSs, such as CSI-RS and associated DMRS.

[0088] C) When the first or second region does not exist, the found subcarriers are the X subcarriers with the lowest or highest index in the third region, wherein the third region has at least X subcarriers that carry associated DMRS.

[0089] D) Another case is that the second region has a higher priority than the first region. In other words, if the second region exists, the X subcarriers that have been found are the subcarriers with the lowest or highest index in the second region. However, if the second region exists and the first region exists, the X subcarriers that have been found are the subcarriers with the lowest or highest index in the first region.

[0090] E) In these cases, PTRS and DMRS cannot be sent simultaneously.

[0091] F) In these cases, PTRS and CSI-RS should be transmitted simultaneously if the following conditions are met.

[0092] i) Data can be transmitted in CSI-RS symbols, or CSI-RS is not used for beam management

[0093] ii) The first or second region exists.

[0094] G) In these cases, CSI-RS includes zero power CSI-RS and non-zero power CSI-RS. CSI-RS can be replaced by other RS, such as SRS.

[0095] like Fig.8D As shown, N=1 and the number of PTRS ports is 2, that is, X=2. DMRS port 1 and port 2 are multiplexed by CDM. In other words, DMRS port 1 and port 2 share the same RE. PTRS port 1 links DMRS port 1. PTRS port 2 links DMRS port 2. Because subcarriers #1 and #2 carry CSI-RS, it has a low priority, while subcarriers #3-#12 have a high priority.

[0096] In this case, since subcarriers #3-#12 do not carry CSI-RS, there is a first region and includes subcarriers #3-#12, and the X subcarriers found are the subcarriers with the lowest index in the first region, i.e., subcarriers #3 and #4. The mapping can be Figure 8B Since X=2, the first region should have at least 2 subcarriers that do not carry CSI-RS. Figure 8G As shown in , since only one subcarrier is not used for CSI-RS, the first region does not exist.

[0097] In another case, since subcarriers #3, #5, #7, #9, #11 carry DMRS and do not carry CSI-RS, there is a second region and includes subcarriers #3, #5, #7, #9, #11, and the found X subcarrier is the subcarrier with the lowest index in the second region, that is, subcarriers #3, #5. The mapping can be Figure 8F Since X=2, the second region should have at least 2 subcarriers that do not carry CSI-RS. At the same time, the second region should have at least 2 subcarriers that carry DMRS.

[0098] When the first and second regions do not exist, the 2 subcarriers found are the subcarriers with the lowest or highest index in the third region. The subcarriers of the third region are the subcarriers that carry the associated DMRS. In this case, the third region includes subcarriers #1, #3, #5, #7 and #9, #11. The PTRS port is then mapped to subcarriers #1 and #3.

[0099] The lowest subcarrier in a region means that some subcarrier index is the lowest. For example, in Fig.8D In the example, if a region includes subcarriers with indices 1, 3, 5, and 7, the lowest 2 subcarriers of the region are subcarriers with indices 1 and 2.

[0100] The highest subcarrier in a region means that some subcarrier index is the highest. For example, in Fig.8D In the example, if a region includes subcarriers with indices 1, 3, 5, and 7, the highest 2 subcarriers in the region are subcarriers with indices 5 and 7.

[0101] Example 1C

[0102] The multiplexing scheme between CSI-RS and data depends on whether CSI-RS conflicts with PTRS.

[0103] The rules in example embodiments 1a and 1b may cause great complexity for the UE. Since PTRS can be predefined on the subcarrier with the lowest or highest subcarrier index, the gNB can avoid configuring CSI-RS resources in the lowest or highest subcarrier among N PRBs. When the UE receives a CSI-RS configuration notifying that the CSI-RS resources and PTRS subcarriers overlap, it means that the CSI-RS overhead is large and there are few REs in the CSI-RS symbol for data transmission.

[0104] Simply put, when PTRS and CSI-RS collide, there will be no data transmission in the CSI-RS symbol. Therefore, CSI-RS and data cannot be multiplexed by FDM, that is, CSI-RS and data cannot be transmitted at the same time, so TDM is used between CSI-RS and data.

[0105] Therefore, for a UE, if PTRS and CSI-RS collide, CSI-RS and data cannot be multiplexed by FDM. If PTRS and CSI-RS do not collide, CSI-RS and data can be multiplexed by FDM. In other words, for a UE, if PTRS and CSI-RS collide, there is no data in the CSI-RS symbol; the UE does not expect to receive data in the CSI-RS symbol. If PTRS and CSI-RS do not collide, there may be data in the CSI-RS symbol. Note that the CSI-RS here is not used for beam management.

[0106] In some embodiments, the gNB uses another signaling transmission to limit the search space of the PDCCH.

[0107] In the PDCCH area, it can be called COREST (Control Channel Resource Set). The UE should blindly search for PDCCH in COREST. Figure 8H As shown, a COREST includes 8 possible PDCCH regions, where a PDCCH region may consist of multiple PRBs. We can also refer to one or more CORESTs as a PDCCH search space.

[0108] Therefore, the gNB can send PDCCH to the UE in any of the 8 PDCCHs. In this case, the UE can blindly search 8 times to detect the PDCCH. Then the complexity of the UE is very high. Specifically, when the traffic load is low, for example: there is only one UE in a cell, so the high complexity of the UE is unnecessary. In order to reduce the complexity of the UE, the gNB can use other signaling transmissions, such as: CSI-RS transmission to limit the search space or certain PDCCH areas in COREST. Therefore, when the traffic load is low, CSI-RS can be configured in the PDCCH area. Figure 8I As shown, if CSI-RS is transmitted in PDCCH regions 2 and 4, the UE does not need to search for PDCCH in regions 2 and 4, which reduces the complexity of the UE. Therefore, when CSI-RS is transmitted in a possible PDCCH region, the UE does not expect to search for PDCCH in a possible PDCCH region.

[0109] In this case, the gNB can configure periodic or semi-persistent CSI-RS in the PDCCH region, where the CSI-RS can be zero-power CSI-RS. When the UE detects the PDCCH, it does not need to search the PDCCH region for CSI-RS transmission. In addition to zero-power CSI-RS and non-zero-power CSI-RS, other signaling may also include some other signals, such as signaling on rate matching resources, or some other signals on certain zero-power signals. The UE will not search for PDCCH regions overlapping with these rate matching resources or with these zero-power signals.

[0110] Example Embodiment #2:

[0111] In the case of the additional DMRS scheme, the PTRS on the OFDM symbol between the pre-DMRS and the additional DMRS can be transmitted on the subcarrier associated with the pre-DMRS, and the PTRS on the OFDM symbol after the additional DMRS in the time slot can be transmitted on the subcarrier associated with the additional DMRS. Fig. 9 As shown, the pre-DMRS configured on subcarrier #1 and subcarrier #7, the PTRS of OFDM symbols #4, #5, #6, #7, and #8 can be configured on subcarrier 1, and the PTRS of OFDM symbols #10, #11, #12, #13, and #14 can be configured on subcarrier 5. This can improve the accuracy of PTRS phase compensation.

[0112] Example Embodiment #3:

[0113] This embodiment can use the following technology to perform PTRS configuration when the additional DMRS and the pre-DMRS are not configured on the same subcarrier. The following scenarios are possible.

[0114] 1) DMRS and PTRS are not transmitted on the same OFDM symbol.

[0115] like Fig.10 As shown, DMRS port 1 is configured on OFDM symbols #3 and #9, so PTRS port should not be configured on these symbols, which can reduce some overhead. The PTRS situation on symbol 9 is the same as DMRS.

[0116] 2) The PTRS port is configured on a subcarrier that is close enough to the DMRS port, or on a subcarrier between two DMRS ports on an OFDM symbol.

[0117] like Fig.10 As shown in FIG. 1 , pre-DMRS is configured on subcarriers #1 and #7, and additional DMRS is configured on subcarriers #5 and #11. PTRS port 1 associated with DMRS port 1 can be configured on these subcarriers. The PTRS situation of OFDM symbol 9 is the same as DMRS port 1, and it is well known that the closer the RE is to the DMRS port, the more accurate the channel estimation on this RE. Therefore, PTRS should select a subcarrier closer to other carriers, such as Fig. 9 As shown, the PTRS port is configured on subcarrier 7.

[0118] 3) PTRS should be configured on subcarriers with more DMRS ports.

[0119] More DMRS ports on a subcarrier means a more accurate estimation of the channel of this subcarrier, and the PTRS configured on this subcarrier can achieve better compensation performance. Fig.11 As shown, DMRS port 1 is configured on OFDM symbols #3 and #13 of subcarrier #1 and subcarrier #7, so these two subcarriers can achieve better channel estimation. The above specification shows that PTRS on OFDM #6 and #10 of subcarrier #7 can achieve better channel estimation than the channel estimation on subcarrier #1. Therefore, PTRS should be configured on subcarrier #7.

[0120] 4) The above principle is also applied to the IFDMA distribution of DMRS. Fig.12 shown.

[0121] Example Embodiment #4:

[0122] The presence information of PTRS indicates the presence of code division multiplexing (CDM) in the time domain of PUCCH. In other words, one signaling is used not only to indicate whether PTRS exists, but also to indicate whether CDM in the time domain is used for uplink control channels. The signaling is RRC signaling.

[0123] In conventional systems, PUCCH (Physical Uplink Control Channel) consists of multiple symbols in the time domain, and then multiple PUCCHs can be multiplexed in these symbols by CDM (Code Division Multiplexing). Typically, OCC (Orthogonal Cover Code) is used between these symbols. CDM in the time domain can increase channel estimation and multiplexing capacity, especially in low frequency bands. However, due to phase noise, the application of CDM in the time domain may be affected by high frequency bands. Typically, phase noise only exists in high frequency bands, which will cause phase rotation between symbols. In this case, the estimated channels of different symbols may be different, and the channel performance of CDM or OCC in the time domain will be significantly degraded.

[0124] Therefore, CDM in the time domain should not be used when phase noise is present, and other multiplexing schemes such as TDM can also be used in phase noise scenarios. At the same time, when phase noise is present, the gNB usually configures the presence of PTRS through RRC signaling. Therefore, when PTRS is configured through RRC signaling, it means that phase noise is present and CDM in the time domain should not be used for PUCCH transmission. Therefore, there is an association between the time domain multiplexing scheme of PUCCH and the PTRS presence indication through RRC signaling. The association can reduce the signaling overhead because the gNB does not need to use additional RRC signaling to notify whether CDM is applied to PUCCH.

[0125] Therefore, in some embodiments, when the presence of PTRS is indicated by RRC signaling, CDM in the PUCCH transmission time domain is not used.

[0126] In some embodiments, when RRC signaling indicates that PTRS is not present, CDM in the PUCCH transmission time domain is used.

[0127] The presence of PTRS indicated by RRC signaling does not necessarily mean that PTRS is actually transmitted. The dynamic presence of PTRS depends on the MCS (Modulation Code Scheme), the allocated bandwidth of the data.

[0128] Typically, the gNB uses 1-bit RRC signaling to indicate whether PTRS exists. In addition, this 1-bit indicates whether CDM in the time domain is used for PUCCH.

[0129] RRC signaling configures RRC1 to indicate the presence of downlink and uplink PTRS, and the presence of PTRS may indicate the absence of CDM in the time domain of PUCCH.

[0130] Taking TD-OCC equal to 2 as an example, for example, if TD-OCC exists, two PUCCHs may be configured as TD-OCC mode.

[0131] The signaling of the presence of PTRS is used to indicate the presence of CDM in the time domain of CSI-RS, DMRS, and PUCCH. If this one signaling indicates the presence of PTRS in both the downlink and uplink, and the absence of PTRS can indicate the presence of CDM in the time domain of all CSI-RS, DMRS, and PUCCH. If this one signaling indicates that PTRS exists only in the uplink, the presence of PTRS can indicate the absence of CDM in the time domain of uplink DMRS and PUCCH.

[0132] Some embodiments may use 1-bit signaling to indicate whether CDM exists in the time domain of CSI-RS, DMRS, and PUCCH. The signaling setting of 1 indicates that the channel estimation difference between OFDM symbols is very small, and CDM may exist in the time domain of CSI-RS, DMRS, and PUCCH. Vice versa.

[0133] It should be understood that a new rule is defined herein to keep PTRS and CSI-RS transmitted on different subcarriers. In some embodiments, if PTRS and CSI-RS (or other RS) overlap on one or more subcarriers, PTRS is configured on a new subcarrier and the new subcarrier may be selected based on the subcarrier index displacement of a subcarrier set. A subcarrier set is a subcarrier configured to transmit a DMRS port associated with a PTRS port.

[0134] It will also be appreciated that some embodiments may use a subcarrier allocation order from the lowest indexed subcarrier to higher indexed subcarriers;

[0135] Some embodiments may use a search order based on OFDM symbol index (pre-loaded DMRS first, followed by additional DMRS).

[0136] Some embodiments may use a threshold for the number of REs configured to transmit data on a subcarrier. The number of REs configured to transmit data being above the threshold means that the subcarrier may be configured to transmit PTRS.

[0137] Some embodiments may select the lowest index subcarrier of a set of subcarriers for allocating transmission resources. The set is the subcarriers of the DMRS port associated with the PTRS, excluding the intersection of the subcarriers of the DMRS and the CSI-RS.

[0138] If no suitable subcarriers are found in this PRB, they can be allocated as follows:

[0139] -Select the lowest index subcarrier associated with the DMRS, e.g. Figure 7 Subcarrier #1 in .

[0140] -Select the next subcarrier that is not allocated to DMRS, for example, Figure 7 Subcarrier #3 in .

[0141] The frequency density parameter of the PTRS configuration is used to select applicable subcarriers in other PRBs.

[0142] In various embodiments, the PTRS ports may be configured on different subcarriers. The PTRS on the symbol after the additional DMRS may be configured on the same subcarrier as the additional DMRS.

[0143] In some embodiments, PTRS and associated DMRS are not transmitted in the same OFDM symbol. The situation of PTRS is the same as that of DMRS on the same OFDM symbol.

[0144] In some embodiments, PTRS should be configured on subcarriers that transmit more DMRS.

[0145] In some embodiments, PTRS should be configured on subcarriers that are closer to all associated DMRS ports.

[0146] In some embodiments, the presence information of the PTRS indicates that there is no CDM in the time domain of the PUCCH.

[0147] In some embodiments, the presence information of the PTRS indicates that there is no CDM in the time domain of the CSI-RS, DMRS, and PUCCH.

[0148] Some embodiments may use 1-bit signaling to indicate whether CDM exists in the time domain of DMRS, CSI-RS, and PUCCH. The signaling setting of 1 indicates that the channel estimation difference between OFDM symbols is very small, and CDM can exist in the time domain of CSI-RS, DMRS, and PUCCH, and vice versa.

[0149] Fig.13 1 is a flow chart of an exemplary method 1300 for wireless communication. The method 1300 may be implemented in a base station of a wireless communication network. Using the method 1300, the base station can transmit reference signal information and send reference signals in a wireless network.

[0150] The method 1300 includes allocating a plurality of transmission resources to a third reference signal according to a subcarrier index of the first reference signal and a predefined order of the first reference signal, the second reference signal, and the second reference signal in step 1302. The transmission resources may include a plurality of subcarriers distributed over one or more OFDM symbols.

[0151] The method 1300 includes using a third reference signal according to the plurality of transmission resources at step 1304. For example, the third reference signal may be used by the device making the allocation to send the third reference signal according to the plurality of allocated transmission resources. For example, the allocated transmission resources may be used to send information of the allocated resources to the wireless device, such as an indication from the base station to the wireless device, so that the wireless device may perform reference signal transmission or reception according to the allocation.

[0152] For example, in some embodiments, the third reference signal may be a PT-RS, such as Figures 1 to 12 The discussion in and PT-RS transmission resource allocation can be based on the subcarriers allocated to DM-RS and the predefined order of PT-RS, DMS-RS and CSI-RS.

[0153] In method 1300, the first reference signal may be a DM-RS. In method 1400, the second reference signal may be a CSI-RS or an SRS.

[0154] In some embodiments, the resources allocated for transmission of the third reference signal may correspond to REs obtained by mapping the third reference signal for a given transmission port on at least one subcarrier in N physical resource blocks, where N is an integer greater than or equal to 1. In some embodiments, the method 1300 may further include allocating the lowest or highest index subcarrier within the N physical resource blocks to transmit the third reference signal when there are selected resources, wherein the selected resources correspond to subcarriers in the N physical resource blocks, which are different from the subcarriers in the N physical resource blocks allocated to the second reference signal. For example, some implementation examples are described with reference to example embodiment 1A. In some embodiments, the method 1300 may further include allocating the lowest or highest index subcarrier within the N physical resource blocks to transmit the third reference signal when there are selected resources, wherein the selected resources correspond to subcarriers in the N physical resource blocks that are different from the subcarriers in the N physical resource blocks allocated to the second reference signal and are the same as the subcarriers in the N physical resource blocks allocated to the first reference signal.

[0155] In some embodiments, when the selected resource is not present, the lowest or highest indexed subcarrier allocated to the first reference signal is reallocated to the third reference signal.

[0156] In some embodiments, allocating resources for transmitting the third reference signal is implemented such that the third reference signal is transmitted on at least some of the same subcarriers as the first reference signal.

[0157] In some embodiments, resources for transmission of the third reference signal are allocated by selecting subcarriers according to a subcarrier shift. In some embodiments, allocating resources to the third reference signal comprises identifying a subcarrier with a lowest or highest possible index in a PRB such that the subcarrier is not allocated for transmission of the second reference signal.

[0158] In some embodiments, method 1300 further comprises allocating resources for data transmission such that a number of allocated resources in subcarriers in a physical resource block is capped at a threshold.

[0159] In some embodiments, method 1300 further comprises allocating resources for data transmission such that when the second reference signal corresponds to a zero-power reference signal, subcarrier resources in a physical resource block allocated for data transmission are capped at a threshold.

[0160] In some embodiments, the method 1300 further includes implementing a multiplexing scheme between the second reference signal and the data according to whether the second reference signal conflicts with the third reference signal.

[0161] Fig.14 A flow chart of an exemplary wireless communication method 1400 is shown. The method may be implemented by a transmission device in a wireless communication network. For example, a base station may implement the method 1400 to allocate transmission resources for various reference signals.

[0162] The method 1400 includes, at step 1402, organizing transmission resources along a two-dimensional grid of transmission symbols and subcarriers in each transmission symbol.

[0163] The method 1400 includes: in step 1404, allocating resources for transmitting a first reference signal, the resources including a first group of subcarriers within a first symbol group.

[0164] The method 1400 includes, at step 1406, allocating resources for transmitting a second reference signal, the resources including a second group of subcarriers within a second symbol group.

[0165] The method 1400 includes: in step 1408, allocating resources for transmitting a third reference signal, wherein the resources for transmitting the third reference signal are selected based on resources for the first transmission signal and / or the second transmission signal according to a set of allocation rules. Figures 1 to 12 Several such rules are presented.

[0166] In the method 1400, the first reference signal may be a DM-RS. In the method 1400, the second reference signal may be a CSI-RS or an SRS. In the method 1400, the third reference signal may be a PT-RS.

[0167] In some embodiments, the resources allocated for transmission of the third reference signal may correspond to REs obtained by mapping the third reference signal for a given transmission port on at least one subcarrier in N physical resource blocks, where N is an integer greater than or equal to 1. In some embodiments, method 1400 may further include allocating the lowest or highest indexed subcarrier within the N physical resource blocks to the transmission of the third reference signal when selected resources are present, wherein the selected resources correspond to subcarriers in the N physical resource blocks that are not allocated to the second reference signal. For example, some implementation examples are described with reference to example embodiment 1A. In some embodiments, method 1400 may further include allocating the lowest or highest indexed subcarrier within the N physical resource blocks to the transmission of the third reference signal when selected resources are present, wherein the selected resources correspond to subcarriers in the N physical resource blocks that are not allocated to the second reference signal and are allocated to the first reference signal.

[0168] In some embodiments, when the selected resource is not present, the lowest or highest indexed subcarrier allocated to the first reference signal is reallocated to the third reference signal.

[0169] In some embodiments, allocating resources for transmitting the third reference signal is implemented such that the third reference signal is transmitted on at least some of the same subcarriers as the first reference signal.

[0170] In some embodiments, resources for transmitting the third reference signal are allocated by selecting subcarriers according to a subcarrier shift. In some embodiments, allocating resources to the third reference signal includes identifying a subcarrier with a lowest or highest possible index in a PRB such that the subcarrier is not allocated to the second reference signal.

[0171] In some embodiments, method 1400 further comprises allocating resources for data transmission such that a number of allocated resources in subcarriers in a physical resource block is capped at a threshold.

[0172] In some embodiments, method 1400 further comprises allocating resources for data transmission such that when the second reference signal corresponds to a zero-power reference signal, subcarrier resources in a physical resource block allocated for data transmission are capped at a threshold.

[0173] In some embodiments, the method 1400 further includes implementing a multiplexing scheme between the second reference signal and the data according to whether the second reference signal conflicts with the third reference signal.

[0174] Fig.15 A flow chart of an example method 1500 of wireless communication is shown. The method 1500 may be implemented at a mobile station.

[0175] The method 1500 includes, at step 1502, receiving an indication of the presence of a reference signal for transmission by a wireless system.

[0176] The method 1500 includes, in step 1504, obtaining from the indication a usage status of code division multiplexing in the time domain in transmission of other signals in the wireless system. As described herein, in some embodiments, the user equipment receives the indication, wherein the other signal includes an uplink control signal, such as a PUCCH. The other signal may be, for example, an uplink control signal. In some embodiments, the reference signal may be a PT-RS. Using the PT-RS, the receiving device may track the phase of the received signal and use this information to mitigate phase noise.

[0177] Fig.16 An example of a wireless device 1600 is shown. The device 1600 can be used to implement various techniques described herein. For example, the device 1600 can be implemented as a base station on the network side, or as a mobile station or UE on the user side. The device 1600 includes one or more antennas 1620, which are used to send and / or receive wireless signals. The wireless signals can be processed by transceiver electronics 1615 during receive or transmit operations. The device 1600 can also include processor electronics 1610 and memory 1605 for storing and executing code. The memory 1605 can be external or internal to the processor electronics 1610.

[0178] Fig.17 An example of a wireless communication network 1700 is shown. The network 1700 includes a base station BS 1702 and a plurality of user devices 1706 that can communicate with each other over a transmission medium 1704. Transmissions from the BS 1702 to the devices 1706 are generally referred to as downlinks or downlink transmissions. Transmissions from the devices 1106 to the BS 1102 are generally referred to as uplinks or uplink transmissions. The transmission medium 1104 is generally a wireless (air) medium. The BS 1102 may also be communicatively coupled to other base stations or other devices in the network via a backhaul or access network connection 1112. The base station BS 1702 may implement a resource allocation strategy as described herein.

[0179] In some embodiments, the method of allocating transmission resources may include the step of allocating a plurality of transmission resources for a phase tracking reference signal based on a predefined order of a phase tracking reference signal, a first reference signal such as a DM-RS, and a second reference signal such as a CSI-RS signal or an SRS. The phase tracking reference signal may be used by a receiver of a signal to track phase noise of the signal received by the receiver.

[0180] In some embodiments, a receiver of a wireless signal may receive a signal distributed and transmitted according to the method 1300 or 1400 described herein and perform measurements using the reference signal to improve the efficiency of wireless communication operations. The measurements may be used for phase tracking, selecting an appropriate modulation scheme, etc.

[0181] The disclosed and other embodiments, modules and functional operations herein may be implemented in digital electronic circuits, or computer software, firmware or hardware, including the structures disclosed herein and their equivalent structures, or one or more combinations thereof. The disclosed and other embodiments may be implemented as one or more computer program products, i.e., one or more computer program instruction modules encoded on a computer-readable medium, or in order to control the operation of a data processing device. The computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a memory device, a combination of substances that affect a machine-readable propagation signal, or one or more combinations thereof. The term "data processing device" includes all devices, apparatuses and machines for processing data, including, for example, a programmable processor, a computer or multiple processors or computers. In addition to hardware, the device may also include code that creates an execution environment for the computer program, such as code constituting processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more thereof. A propagated signal is an artificially generated signal, such as a machine-generated electrical, optical or electromagnetic signal, which is generated to encode information for transmission to a suitable receiver device.

[0182] A computer program (also referred to as a program, software, software application, script, or code) may be written in any form of programming language (including compiled or interpreted languages) and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program may be stored as part of a file containing other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to related programs, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or portions of code). A computer program may be deployed to be executed on a single computer or on multiple computers located at one site or distributed across multiple sites and interconnected by a communications network.

[0183] The processes and logic flows described herein can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, for example, an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit), and the apparatus can also be implemented as a special-purpose logic circuit, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).

[0184] Processors suitable for executing computer programs include, for example, general-purpose and special-purpose microprocessors and any one or more processors of any type of digital computer. Typically, the processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, the computer also includes or is operably coupled to receive data or pass data to one or more large-capacity storage devices for storing data, such as magnetic, magneto-optical or optical disks. However, the computer does not require such a device. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including, for example, semiconductor memory devices, such as EPROM, EEPROM and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD ROM and DVD-ROM disks. The processor and memory may be supplemented by or integrated into special-purpose logic circuits.

[0185] Although this document contains many details, these should not be interpreted as limitations on the scope of the claimed invention or what may be claimed, but rather as descriptions of features of specific embodiments. Certain features described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination. In addition, although the above-mentioned features may be described as working in certain combinations, or even initially claimed as such, in some cases, one or more features may be removed from the combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination. Similarly, although operations are described in a particular order in the accompanying drawings, it should not be understood as requiring that such operations be performed in the particular order or sequence shown, or that all illustrated operations be performed, in order to achieve the desired results.

[0186] Only a few examples and implementations are disclosed. Variations, modifications, and enhancements to the described examples, implementations, and other implementations may be made based on what is disclosed.

Claims

1. A wireless communication method, characterized in that: include: allocating a plurality of transmission resources to the third reference signal according to a subcarrier index of the first reference signal and a predefined order of the third reference signal, the first reference signal and the second reference signal, The first reference signal includes a demodulation reference signal for channel estimation at a receiver, the second reference signal includes a channel state information reference signal, and the third reference signal includes a phase tracking reference signal; using the third reference signal according to the plurality of transmission resources, The multiple transmission resources include multiple subcarriers distributed on one or more orthogonal frequency division multiplexing symbols; Allocating resources for transmitting the third reference signal is performed such that the third reference signal is transmitted on at least some of the same subcarriers as the first reference signal.

2. The method according to claim 1, characterized in that The second reference signal is used to calculate channel state information or measure a reference signal at a receiver.

3. The method according to claim 1, characterized in that The third reference signal is used to track the phase noise of the signal received by the receiver.

4. The method according to any one of claims 1 to 3, characterized in that: Allocating resources to transmission of the third reference signal includes mapping the third reference signal to a given transmission port on at least one subcarrier in N physical resource blocks, where N is an integer greater than or equal to 1.

5. The method according to claim 4, characterized in that Also includes: Allocate a lowest or highest indexed subcarrier within the N physical resource blocks for transmission of the third reference signal when selected resources are present, wherein the selected resources correspond to subcarriers in the N physical resource blocks that are different from subcarriers allocated to the second reference signal in the N physical resource blocks.

6. The method according to claim 4, characterized in that Also includes: within the N physical resource blocks, allocating a lowest or highest indexed subcarrier to transmission of the third reference signal when selected resources are present, wherein the selected resources correspond to subcarriers in the N physical resource blocks that are different from subcarriers allocated to the second reference signal in the N physical resource blocks, but are the same as subcarriers allocated to the first reference signal in the N physical resource blocks.

7. The method according to claim 5 or 6, characterized in that: Also includes: The lowest or highest indexed subcarrier allocated to the first reference signal is reallocated to transmission of the third reference signal.

8. The method according to claim 5 or 6, characterized in that: Resources for transmitting the third reference signal are allocated by selecting subcarriers according to subcarrier shifting.

9. The method according to claim 5 or 6, characterized in that: Identifying includes using a frequency density parameter associated with the third reference signal.

10. The method according to claim 1, characterized in that Also includes: Resources are allocated to data transmission such that the number of allocated resources in subcarriers in a physical resource block is upper bounded by a threshold.

11. The method according to claim 1, characterized in that: Also includes: Resources are allocated to data transmission so that when the second reference signal corresponds to a zero-power reference signal, the subcarrier resources in the physical resource block allocated to the data transmission are upper bounded by a threshold.

12. The method according to claim 4, characterized in that include: The lowest or highest index subcarrier is allocated within the N physical resource blocks to transmit the third reference signal.

13. The method according to claim 1, characterized in that Also includes: A multiplexing scheme between the second reference signal and data is implemented according to whether the second reference signal conflicts with the third reference signal.

14. A wireless communication device, comprising a memory and a processor, characterized in that: The memory is configured to store processor executable code, and the processor is configured to read the code and implement the method of any one of claims 1 to 13.

15. A computer program product, comprising computer-readable program medium codes stored thereon, wherein when the codes are executed by a processor, the processor is caused to implement the method according to any one of claims 1 to 13.

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