Transmission and reception of downlink control information

Abstract

Embodiments of the present disclosure relate to methods, devices, and computer-readable media for transmitting and receiving DCI in a single-carrier based downlink control channel. The communication method includes: at a terminal device, receiving a reference signal of a downlink control channel associated with the terminal device via a first time-frequency resource, the first time-frequency resource being allocated for transmission of the reference signal; determining, based on the reference signal, a subset of second time-frequency resources from a set of second time-frequency resources assigned to the downlink control channel; and receiving downlink control information via the subset of second time-frequency resources. The method further includes: at a network device, determining the first time-frequency resource and the second time-frequency resource; determining a reference signal based on the second time-frequency resource; and transmitting the reference signal and DCI via the first time-frequency resource and the second time-frequency resource, respectively. Embodiments of the present disclosure can reduce the complexity of blind detection of the downlink control channel while supporting low PAPR and better coverage using a single-carrier based downlink control channel structure.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of telecommunications, and in particular, to methods, devices, and computer storage media for transmitting and receiving downlink control information (DCI). Background Art

[0002] In recent research on new radio (NR) technology above 52.6 GHz, it is generally agreed that low coverage of cells and power amplifiers (PAs) with low power efficiency in high frequency bands are key issues to be addressed, and waveforms with low peak-to-average power ratio (PAPR) should be studied. In this case, single carrier is considered for downlink transmission due to the low PAPR of its time-domain signal sequence. Therefore, downlink control channels based on single carrier, such as the physical downlink control channel (PDCCH), have received much attention. Summary of the Invention

[0003] Generally, embodiments of the present disclosure provide methods, devices, and computer storage media for transmitting and receiving DCI in a downlink control channel based on single carrier.

[0004] In a first aspect, a communication method is provided. The method includes: at a terminal device, receiving a reference signal of a downlink control channel associated with the terminal device via a first time-frequency resource, the first time-frequency resource being allocated for transmission of the reference signal; determining a subset of a second time-frequency resource from a set of second time-frequency resources allocated to the downlink control channel based on the reference signal; and receiving downlink control information via the subset of the second time-frequency resource.

[0005] In a second aspect, a communication method is provided. The method includes: at a network device, determining a first time-frequency resource and a second time-frequency resource, the first time-frequency resource being allocated for transmission of a reference signal of a downlink control channel associated with a terminal device, the second time-frequency resource being allocated to the downlink control channel; determining the reference signal based on the second time-frequency resource; and transmitting the reference signal and downlink control information via the first time-frequency resource and the second time-frequency resource, respectively.

[0006] In a third aspect, a terminal device is provided. The terminal device includes a processor and a memory coupled to the processor. The memory stores instructions that, when executed by the processor, cause the terminal device to perform the method according to the first aspect of the present disclosure.

[0007] In a fourth aspect, a network device is provided. The network device includes a processor and a memory coupled to the processor. The memory stores instructions that, when executed by the processor, cause the network device to perform the method according to the second aspect of the present disclosure.

[0008] In a fifth aspect, there is provided a computer-readable medium having instructions stored thereon. When the instructions are executed on at least one processor, the at least one processor is caused to execute the method according to the first aspect of the present disclosure.

[0009] In a sixth aspect, there is provided a computer-readable medium having instructions stored thereon. When the instructions are executed on at least one processor, the at least one processor is caused to execute the method according to the second aspect of the present disclosure.

[0010] Other features of the present disclosure will become readily apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other objects, features and advantageous effects of the present disclosure will become more apparent from the more detailed description of some embodiments of the present disclosure in the accompanying drawings, wherein:

[0012] Figure 1 An example communication network in which some embodiments of the present disclosure may be implemented is shown;

[0013] Figure 2 A schematic diagram showing a process for transmitting and receiving DCI in a single-carrier based downlink control channel according to an embodiment of the present disclosure is shown;

[0014] Figure 3 A schematic time-frequency diagram showing data transmission in a single-carrier based physical downlink control channel (PDCCH) associated with a terminal device according to some embodiments of the present disclosure is shown;

[0015] Figure 4 A schematic time-frequency diagram showing the association of a sequence of demodulation reference signals (DMRS) with time-frequency resources for PDCCH (hereinafter also referred to as second time-frequency resources) according to some embodiments of the present disclosure is shown;

[0016] Figure 5 A schematic time-frequency diagram showing the association of a sequence of DMRS with the aggregation level of time-frequency resources for PDCCH according to some embodiments of the present disclosure is shown;

[0017] Figure 6 A schematic time-frequency diagram showing the association of first time-frequency resources for DMRS with second time-frequency resources for PDCCH according to some embodiments of the present disclosure is shown;

[0018] Figure 7 An example communication method implemented at a terminal device according to some embodiments of the present disclosure is shown;

[0019] Figure 8illustrates an example communication method implemented at a network device according to some embodiments of the present disclosure; and

[0020] Figure 9 is a simplified block diagram of a device suitable for implementing embodiments of the present disclosure.

[0021] In all the figures, the same or similar reference numerals denote the same or similar elements. Detailed Description

[0022] The principles of the present disclosure will now be described with reference to some embodiments. It should be understood that the description of these embodiments is for illustrative purposes only and helps those skilled in the art to understand and implement the present disclosure without implying any limitation on the scope of the disclosure. The disclosure described herein can be implemented in various ways different from those described below.

[0023] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0024] As used herein, the term "terminal device" refers to any device having wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to: user equipment (UE), personal computer, desktop computer, mobile phone, cellular phone, smart phone, personal digital assistant (PDA), portable computer, tablet computer, wearable device, Internet of Things (IoT) device, Internet of Everything (IoE) device, machine type communication (MTC) device, vehicle-mounted device for V2X communication (where X represents pedestrian, vehicle, or infrastructure / network), or an image capture device such as a digital camera, gaming device, music storage and playback device, or an Internet tool that allows wireless or wired Internet access and browsing. The term "terminal device" may be used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device. Additionally, the term "network device" refers to a device capable of providing or hosting a cell or coverage with which a terminal device can communicate. Examples of network devices include, but are not limited to: Node B (NodeB or NB), evolved Node B (eNodeB or eNB), next-generation Node B (gNB), transmit receive point (TRP), remote radio unit (RRU), radio head (RH), remote radio head (RRH), low-power nodes such as femto nodes, pico nodes, etc.

[0025] In one embodiment, a terminal device may be connected to a first network device and a second network device. One of the first network device and the second network device may be a master node, and the other may be a secondary node. The first network device and the second network device may use different radio access technologies (RATs). In one embodiment, the first network device may be a first RAT device, and the second network device may be a second RAT device. In one embodiment, the first RAT device is an eNB and the second RAT device is a gNB. Information related to different RATs may be sent from at least one of the first network device and the second network device to the terminal device. In one embodiment, a first piece of information may be sent from the first network device to the terminal device, and a second piece of information may be sent from the second network device to the terminal device directly or via the first network device. In one embodiment, information related to the configuration of the terminal device configured by the second network device may be sent from the second network device via the first network device. Information related to the reconfiguration of the terminal device configured by the second network device may be sent from the second network device to the terminal device directly or via the first network device.

[0026] As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly indicates otherwise. The term "comprising" and its variants will be construed as open-ended terms meaning "including but not limited to". The term "based on" will be construed as "at least partially based on". The terms "one embodiment" and "an embodiment" will be construed as "at least one embodiment". The term "another embodiment" will be construed as "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may be included below.

[0027] In some examples, a value, process, or device is referred to as "optimal", "lowest", "highest", "minimum", "maximum", etc. It should be understood that such descriptions are intended to indicate that a selection can be made among many alternative functions used, and such a selection is not necessarily better, smaller, higher, or more preferred than other selections.

[0028] As is known, in NR technology, the concept of a control resource set (CORESET) is introduced to carry information such as multiple orthogonal frequency division multiplexing (OFDM) symbols or single-carrier symbols occupied by a downlink control channel such as PDCCH in the time domain and the frequency band occupied in the frequency domain. In addition, the concept "search space" is used to define the possible downlink resource blocks for carrying the downlink control channel.

[0029] In a case where a terminal device is supposed to receive DCI in a downlink control channel, the possible location of the downlink control channel or a set of time-frequency resources can be determined based on a CORESET and a search space, and DCI can be determined by performing a blind detection process in the set of time-frequency resources. During the blind detection process, for each time-frequency resource in the set of time-frequency resources, the terminal device can determine whether the time-frequency resource is desired by performing a cyclic redundancy check (CRC) until the CRC is successful and the desired time-frequency resource is determined. Thereby, DCI can be obtained from the desired time-frequency resource.

[0030] In the context of a single-carrier based downlink control channel and considering the above-mentioned blind detection process, embodiments of the present disclosure provide an improved solution for the transmission and reception of DCI in order to reduce the complexity of blind detection of the downlink control channel while supporting low PAPR and better coverage by utilizing the single-carrier based downlink control channel structure. The principles and implementations of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0031] Figure 1 A schematic diagram of an example communication network 100 in which embodiments of the present disclosure can be implemented is shown. As Figure 1 shown, the communication network 100 may include a network device 110 and terminal devices 120 served by the network device 110. It should be understood that Figure 1 the number of devices in is given for illustrative purposes and does not imply any limitation to the present disclosure. The communication network 100 may include any suitable number of network devices and / or terminal devices suitable for implementing embodiments of the present disclosure.

[0032] As Figure 1 shown, the network device 110 may communicate with the terminal device 120 via a downlink channel such as a wireless communication downlink channel. For example, the network device 110 may send DCI to the terminal device 120 via a downlink control channel such as a PDCCH. Additionally, the network device 110 may send a reference signal to the terminal device 120 for channel assessment and related demodulation of downlink transmissions. For example, the reference signal may be any one or more of a DMRS, a cell reference signal (CRS), a multicast broadcast single frequency network (MBSFN) reference signal, a positioning reference signal (PRS), and a channel state information-reference signal (CSI-RS). It should be noted that the reference signal may be any downlink reference signal existing in the prior art or developed in the future.

[0033] Communications in the communication network 100 may conform to any suitable standards, including but not limited to: Global System for Mobile Communications (GSM), Long Term Evolution (LTE), LTE Evolution, Advanced LTE (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE Radio Access Network (GERAN), Machine Type Communication (MTC), etc. In addition, communications may be performed according to any generation of communication protocols known currently or to be developed in the future. Examples of communication protocols include but are not limited to: First Generation (1G), Second Generation (2G), 2.5G, 2.75G, Third Generation (3G), Fourth Generation (4G), 4.5G, Fifth Generation (5G) communication protocols.

[0034] Figure 2 A schematic diagram of a process 200 for transmitting and receiving DCI in a single-carrier based downlink control channel according to an embodiment of the present disclosure is shown. For the purpose of discussion, the process 200 will be described with reference to Figure 1 The process 200 may include a network device 110 and a terminal device 120 as shown in Figure 1 FIG.

[0035] As shown in Figure 2 FIG., the network device 110 may determine 210 a first time-frequency resource and a second time-frequency resource. The first time-frequency resource is allocated for the transmission of a reference signal of a downlink control channel associated with the terminal device 120, and the second time-frequency resource is allocated to the downlink control channel. As described above, the reference signal may be any downlink reference signal existing in the prior art or to be developed in the future. For the purpose of discussion, the following description will be made by taking the DMRS as an example of the reference signal and the PDCCH as an example of the downlink control channel.

[0036] In some embodiments, the first time-frequency resource and the second time-frequency resource are predetermined. In some alternative embodiments, the first time-frequency resource may be selected from a set of first time-frequency resources allocated for reference signal transmission. In some alternative embodiments, the second time-frequency resource may be selected from a set of second time-frequency resources allocated to the downlink control channel. In this regard, examples will be described in conjunction with Figure 3 FIG.

[0037] Figure 3 A schematic time-frequency diagram 300 according to some embodiments of the present disclosure is shown, which shows data transmission in a single-carrier based PDCCH associated with a terminal device. For the purpose of discussion, the diagram 300 will be described with reference to Figure 1 FIG. 300 may relate to a network device 110 and a terminal device 120 as shown in Figure 1 FIG.

[0038] As shown in Figure 3As shown, the time-frequency resources defined in CORESET 330 are allocated to a terminal device (e.g., terminal device 120), and this resource is used for PDCCH detection. The broadband DMRS is configured within all resource element groups (REGs) of a set of consecutive resource blocks (RBs) in CORESET 330.

[0039] In some embodiments, the first symbol 310 of all RBs or REGs within the frequency range of CORESET 330 is allocated for the transmission of the DMRS of the PDCCH. The M symbols 320 after the first symbol 310 are allocated to the PDCCH, where M can be 1, 2, or 3. One of the second time-frequency resources in the set of second time-frequency resources associated with the terminal device 120 is shown by 340 and is also referred to herein as a PDCCH candidate.

[0040] In some embodiments, the DMRS is time-division multiplexed with the PDCCH. That is, there is no transmission of the PDCCH on the first symbol, and there is no transmission of the DMRS on these M symbols. In some embodiments, the phase-tracking reference signal (PTRS) can be frequency-division multiplexed on N of these M symbols, where 0 ≤ N ≤ M. For example, the PTRS can be mapped to one or more of the resource elements (REs) #1, #5, #9 within a physical resource block (PRB).

[0041] For example, in some embodiments, the network device 110 can configure X RBs in the frequency domain and Y symbols in the time domain for the terminal device 120, where X and Y are positive integers. For example, 1 ≤ X ≤ 400 and 1 ≤ Y ≤ 4. In some embodiments, the X RBs in the frequency domain and the Y symbols in the time domain can be represented as a CORESET. In some embodiments, the network device 110 can send DCI to the terminal device 120 in the PDCCH. In some embodiments, the PDCCH can be mapped within the time and frequency ranges of the CORESET. In some embodiments, the PDCCH can be mapped to R resource blocks in the frequency domain and S symbols in the time domain, where R and S are positive integers, and 1 ≤ R ≤ X and 1 ≤ S ≤ Y. In some embodiments, there is a reference signal associated with the PDCCH. For example, the reference signal can be the DMRS. In some embodiments, there is a sequence for transmitting the reference signal.

[0042] In some embodiments, there may be parameters associated with the PDCCH (also referred to herein as second predetermined parameters). The parameter may include at least one of the following: aggregation level, starting index of a control channel element (CCE), index of a set of search spaces, index of a search space, index of a CORESET, index of a PDCCH candidate. It should be noted that the parameters for the PDCCH are not limited to the examples listed and may be any other suitable parameters.

[0043] In some embodiments, there may be G possible values for the parameters associated with the PDCCH, where G is a positive integer and G>1.

[0044] In some embodiments, there may be parameters for sequence generation and / or resource mapping of a reference signal (also referred to herein as first predetermined parameters). The parameter may include at least one of the following: index of the sequence of the reference signal, length of the sequence of the reference signal, initial value of the sequence of the reference signal, index of the base sequence group of the sequence of the reference signal, index of the base sequence within the base sequence group, and RE offset for mapping of the sequence. It should also be noted that the parameters of the sequence of the reference signal are not limited to the examples listed and may be any other suitable parameters.

[0045] In some embodiments, there may be H possible values for the parameters for sequence generation of a reference signal, where H is a positive integer and H>1.

[0046] In some embodiments, at least for two different values of the parameters associated with the PDCCH, the parameter values for sequence generation of the reference signal associated with the PDCCH may be different. In some embodiments, the two different values of the parameters associated with the PDCCH may be within the same CORESET. In some embodiments, the lengths of the sequences of the reference signals associated with PDCCHs having different parameter values may be the same.

[0047] In some embodiments, the parameter associated with the PDCCH may be one of the parameters for sequence generation of the reference signal associated with the PDCCH.

[0048] In some embodiments, the G (where G is a positive integer and G>1) possible values of the parameters associated with the PDCCH may be divided into F groups (where F is a positive integer and 1<F≤G). In some embodiments, the number of values in different groups may be the same or different. In some embodiments, it may not be necessary to group the G values, or alternatively, there are G groups and there is one value in each group.

[0049] In some embodiments, for a reference signal associated with a PDCCH having F different groups and / or G different parameter values, there may be F and / or G different parameter values. And each value of the parameters of the sequence for the reference signal is associated with a group and / or value of the parameters for the PDCCH.

[0050] In some embodiments, the sequence of the reference signal may be where M ZC is the length of the sequence, is the base sequence, α is the cyclic shift of the base sequence, and μ is the index of the sequence and / or sequence group. For example, α may be at least one value in {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}.

[0051] In some embodiments, for generating the sequence of the reference signal associated with the PDCCH, the value of the cyclic shift and / or the value of the sequence index and / or the value of the sequence group index are based on the value of the aggregation level.

[0052] In some embodiments, the RE offset for the resource mapping of the reference signal associated with the PDCCH may be at least one of {0, 1, 2, 3}. In some embodiments, for the resource mapping of the reference signal associated with the PDCCH, the value of the RE offset is based on the value of the aggregation level.

[0053] In some embodiments, for the PDCCH candidates within one CORESET, the number of values of the aggregation level may be E. For example, E may be at least one of {1, 2, 3, 4, 5, 6, 7, 8}. For example, the values of the aggregation level may be at least one of {1, 2, 4, 8, 16, 32, 64}. In some embodiments, the E different values of the aggregation level of the PDCCH may be associated with the E different values of the cyclic shift of the same base sequence of the reference signal. In some embodiments, the E different values of the aggregation level of the PDCCH may be associated with the E different values of the sequence and / or sequence group index of the reference signal. In some embodiments, the E different values of the aggregation level of the PDCCH may be associated with the E different values of the RE offset for the resource mapping of the reference signal.

[0054] Return Figure 2 , the network device 110 may determine 220 the reference signal based on the second time-frequency resource. According to the embodiments of the present disclosure described above, different parameters of the reference signal may be associated with different parameters of the second time-frequency resource for the downlink control channel. In this way, the reference signal may carry some information about the second time-frequency resource, and after demodulation of the reference signal, the scope of blind detection of the downlink control channel may be reduced, and the efficiency of blind detection of the downlink control channel may be improved.

[0055] In some embodiments, the network device 110 may determine 221 the predetermined parameters of the second time-frequency resource (also referred to herein as the second predetermined parameters). In some embodiments, the second predetermined parameters may include at least one of the following: the aggregation level of the second time-frequency resource, the starting index of the CCE of the second time-frequency resource, the index of the second time-frequency resource, the index of the set of the second time-frequency resources, the index of the search space associated with the terminal device 120, and the index of the set of the search spaces associated with the terminal device 120. It should be noted that the second predetermined parameters of the second time-frequency resource for the downlink control channel are not limited to the listed examples and may be any other suitable parameters.

[0056] After determining the second predetermined parameters of the second time-frequency resource, the network device 110 may determine 222 the predetermined parameters of the reference signal (also referred to herein as the first predetermined parameters) based on the second predetermined parameters. In some embodiments, the first predetermined parameters may include at least one of the following: the sequence of the reference signal, the cyclic shift of the sequence of the reference signal, and the time-frequency resource of the reference signal. It should be noted that the first predetermined parameters of the reference signal are not limited to the listed examples and may be any other suitable parameters.

[0057] In some embodiments, the sequence of the reference signal may include at least one of the following: the index of the sequence of the reference signal, the length of the sequence of the reference signal, the initial value of the sequence of the reference signal, the index of the base sequence group of the sequence of the reference signal, the index of the base sequence within the base sequence group, and the RE offset for the mapping of the sequence. It should also be noted that the parameters of the reference signal sequence are not limited to the listed examples and may be any other suitable parameters.

[0058] For example, assume that different sequences of the reference signal are associated with different second time-frequency resources of the downlink control channel. The network device 120 may determine 221 the index of the second time-frequency resource of the downlink control channel and may also determine 222 the corresponding sequence of the reference signal based on the determined index.

[0059] Figure 4 FIG. 400 is a schematic time-frequency diagram showing the association of DMRS sequences with time-frequency resources for PDCCH according to some embodiments of the present disclosure. Figure 4 The reference symbols 410 and 411 in FIG. 400 indicate the corresponding DMRS sequences carried by the first symbol, Figure 4 The reference symbol 420 in FIG. 400 indicates the DCI carried by the subsequent symbol, Figure 4 The reference symbol 430 in FIG. 400 indicates the CORESET, while Figure 4 The reference symbols 440 and 441 in FIG. 400 indicate the corresponding PDCCH candidates. Figure 4The time-frequency diagram 401 therein shows that the DMRS sequence 410 is associated with the PDCCH candidate 440, while Figure 4 the time-frequency diagram 402 therein shows that another DMRS sequence 411 is associated with another PDCCH candidate 441.

[0060] As another example, assume that different sequences of reference signals are associated with different aggregation levels of the second time-frequency resource of the downlink control channel. The network device 120 may determine 221 the aggregation level of the second time-frequency resource of the downlink control channel, and may also determine 222 the corresponding sequence of the reference signal based on the determined aggregation level.

[0061] Figure 5 The schematic time-frequency diagram 500 showing the association between the DMRS sequence and the aggregation level of the time-frequency resource for PDCCH according to some embodiments of the present disclosure is shown. Figure 5 The reference symbols 510 and 511 therein indicate the corresponding DMRS sequences carried by the first symbol, Figure 5 the reference symbol 520 therein indicates the DCI carried by the subsequent symbol, Figure 5 the reference symbol 530 therein indicates the CORESET, and Figure 5 the reference symbols 540 and 541 therein indicate the PDCCH candidates with corresponding aggregation levels. Figure 5 The time-frequency diagram 501 therein shows that the DMRS sequence 510 is associated with the PDCCH candidate 540, while Figure 5 the time-frequency diagram 502 therein shows that another DMRS sequence 511 is associated with another PDCCH candidate 541.

[0062] As yet another example, assume that different time-frequency resources of the reference signal are associated with different time-frequency resources of the downlink control channel. The network device 120 may determine 221 the index of the second time-frequency resource of the downlink control channel, and may also determine 222 the corresponding index of the first time-frequency resource for the reference signal based on the index of the second time-frequency resource.

[0063] Figure 6 The schematic time-frequency diagram 600 showing the association between the first time-frequency resource for DMRS and the second time-frequency resource for PDCCH according to some embodiments of the present disclosure is shown. Figure 6 The reference symbols 601-604 therein respectively indicate the first symbol carrying the DMRS. Figure 6 The reference symbols 610-640 therein indicate different time-frequency resources for the DMRS. The time-frequency resources 610-640 are associated with different PDCCH candidates. It should be noted that Figures 4 to 6 these are only examples for illustration, and the present disclosure is not limited by these examples, but many other embodiments can be conceived based on the present disclosure.

[0064] Return Figure 2 After determining the first predetermined parameter of the reference signal, network device 110 may generate the reference signal 223 based on the first predetermined parameter. In some embodiments, the reference signal may be generated by transforming a base sequence according to the first predetermined parameter. For example, the base sequence may be a Zadoff-Chu (ZC) root sequence. In the case of the above example, the reference signal may be generated by performing a corresponding cyclic shift on the ZC root sequence. It should be noted that the base sequence of the reference signal is not limited to the listed examples and may be any other suitable sequence.

[0065] After determining the reference signal, network device 110 may transmit the reference signal and DCI via the first time-frequency resource and the second time-frequency resource, respectively 230. In some embodiments, network device 110 may time-division multiplex the reference signal and DCI. For example, as previously combined Figure 3 As discussed, network device 110 may transmit the reference signal on the first symbol and transmit DCI on subsequent symbols. It should be noted that the transmission of the reference signal and DCI is not limited to the listed examples and may be performed in any other suitable manner.

[0066] Accordingly, terminal device 120 may receive the reference signal 240. In some embodiments in which the first time-frequency resource is predetermined, terminal device 120 may obtain the reference signal via the predetermined first time-frequency resource. In some embodiments in which a set of first time-frequency resources is allocated for reference signal transmission, terminal device 120 may attempt to receive the reference signal from each of the first time-frequency resources in the set of first time-frequency resources until the reference signal is correctly received.

[0067] After receiving the reference signal, terminal device 120 may determine 250 a subset of the second time-frequency resources from the set of second time-frequency resources assigned to the downlink control channel. As described above, terminal device 120 may determine the set of second time-frequency resources based on the information in the search space and CORESET associated with terminal device 120, but terminal device 120 does not know which second time-frequency resource carries the DCI associated with it. Based on the received reference signal, terminal device 120 may determine a subset of the second time-frequency resources from the determined set of second time-frequency resources.

[0068] In some embodiments, terminal device 120 may determine 251 the first predetermined parameter of the reference signal and determine 252 the second predetermined parameter associated with the subset of the second time-frequency resources based on the first predetermined parameter. The association between the first predetermined parameter and the second predetermined parameter is similar to that described in processes 221 and 222 and Figures 4 to 6 Therefore, the detailed description thereof will not be repeated here.

[0069] After determining the second predetermined parameter associated with the subset of the second time-frequency resources, the terminal device 120 may determine, from the set of the second time-frequency resources, a second time-frequency resource having the second predetermined parameter as one of the second time-frequency resources in the subset of the second time-frequency resources.

[0070] After determining the subset of the second time-frequency resources, the terminal device 120 may receive 260 DCI via the subset of the second time-frequency resources. In some embodiments, the terminal device 120 may attempt to receive the DCI associated with each of the second time-frequency resources in the subset of the second time-frequency resources until the DCI is correctly received.

[0071] According to Figure 2 the process in, the scope of blind detection of the downlink control channel associated with the terminal device 120 can be reduced, and the complexity of blind detection can also be reduced. At the same time, with the single-carrier-based downlink control channel structure, low PAPR and better coverage can be achieved.

[0072] Corresponding to Figure 2 the process described in, embodiments of the present disclosure provide communication methods implemented at the terminal device and the network device. The following will refer to Figure 7 and Figure 8 to describe these methods.

[0073] Figure 7 FIG. shows an example communication method 700 implemented at a terminal device according to some embodiments of the present disclosure. For example, the method 700 may be executed at the terminal device 120 as shown in Figure 1 . For the purpose of discussion, hereinafter, the method 700 will be described with reference to Figure 1 . It should be understood that the method 700 may include additional blocks not shown and / or some of the shown blocks may be omitted, and the scope of the present disclosure is not limited thereto.

[0074] At block 710, the terminal device 120 may receive a reference signal of the downlink control channel associated with the terminal device via a first time-frequency resource allocated for reference signal transmission. In some embodiments, the reference signal may be a DMRS. In some alternative or additional embodiments, the reference signal may be any one or more of a cell reference signal (CRS), a multicast broadcast single frequency network (MBSFN) reference signal, a positioning reference signal (PRS), and a channel state information reference signal (CSI-RS). It should be noted that the reference signal may be any downlink reference signal existing in the prior art or developed in the future. In some embodiments, the first time-frequency resource is selected from a set of first time-frequency resources allocated for reference signal transmission.

[0075] At block 720, the terminal device 120 may determine a subset of the second time-frequency resources from a set of second time-frequency resources assigned to the downlink control channel based on a reference signal. In some embodiments, the first time-frequency resources may be time-division multiplexed with the second time-frequency resources.

[0076] In some embodiments, the terminal device 120 may determine a first predetermined parameter of the reference signal, determine a second predetermined parameter associated with the subset of the second time-frequency resources based on the first predetermined parameter, and determine, from the set of second time-frequency resources, a second time-frequency resource having the second predetermined parameter as one of the second time-frequency resources in the subset of the second time-frequency resources.

[0077] In some embodiments, the first predetermined parameter may include at least one of the following: a sequence of the reference signal, a cyclic shift of the sequence of the reference signal, and a time-frequency resource of the reference signal. In some embodiments, the sequence of the reference signal may include at least one of the following: an index of the sequence of the reference signal, a length of the sequence of the reference signal, an initial value of the sequence of the reference signal, an index of a base sequence group of the sequence of the reference signal, an index of a base sequence within the base sequence group, and a RE offset for mapping of the sequence.

[0078] In some embodiments, the second predetermined parameter may include at least one of the following: an aggregation level of the second time-frequency resource, a start index of a control channel element for the second time-frequency resource, an index of the second time-frequency resource, an index of the set of the second time-frequency resources, an index of a search space associated with the terminal device 120, and an index of a set of search spaces associated with the terminal device 120.

[0079] At block 730, the terminal device 120 may receive DCI via the subset of the second time-frequency resources. In this way, the scope of blind detection of the downlink control channel associated with the terminal device 120 may be reduced, and the complexity of blind detection may also be reduced.

[0080] Figure 8 An example communication method 800 implemented at a network device according to some embodiments of the present disclosure is shown. For example, method 800 may be executed at the network device 110 as Figure 1 shown. For purposes of discussion, method 800 will be described below with reference to Figure 1 It should be understood that method 800 may include additional blocks not shown and / or some of the shown blocks may be omitted, and the scope of the present disclosure is not limited thereto.

[0081] As Figure 8As shown, in block 810, the network device 110 may determine a first time-frequency resource and a second time-frequency resource, the first time-frequency resource being allocated for transmission of a reference signal of a downlink control channel associated with the terminal device, and the second time-frequency resource being allocated to the downlink control channel. In some embodiments, the first time-frequency resource and the second time-frequency resource may be predetermined. In some embodiments, the first time-frequency resource may be selected from a set of first time-frequency resources allocated for transmission of a reference signal. In some embodiments, the second time-frequency resource may be selected from a set of second time-frequency resources allocated to a downlink control channel.

[0082] At block 820, network device 110 may determine a reference signal based on the second time-frequency resource. In some embodiments, network device 110 may determine a second predetermined parameter for the second time-frequency resource, determine a first predetermined parameter for the reference signal based on the second predetermined parameter, and generate the reference signal based on the first predetermined parameter.

[0083] In some embodiments, the first predetermined parameter may include at least one of the following: a sequence of a reference signal, a cyclic shift of the sequence of the reference signal, and a time-frequency resource of the reference signal. In some embodiments, the sequence of the reference signal may include at least one of the following: an index of the sequence of the reference signal, a length of the sequence of the reference signal, an initial value of the sequence of the reference signal, an index of a base sequence group of the sequence of the reference signal, an index of a base sequence within a base sequence group, and an RE offset for mapping of the sequence.

[0084] In some embodiments, the second predetermined parameter may include at least one of the following: an aggregation level of the second time-frequency resources, a starting index of a control channel unit of the second time-frequency resources, an index of the second time-frequency resources, an index of a set of second time-frequency resources, an index of a search space associated with the terminal device, and an index of a set of search spaces associated with the terminal device.

[0085] At block 830, the network device 110 may send a reference signal and downlink control information via the first time-frequency resource and the second time-frequency resource, respectively. In some embodiments, the first time-frequency resource may be time division multiplexed with the second time-frequency resource.

[0086] Figure 7 and Figure 8 The implementation of the method described in substantially corresponds to combining Figure 2 The process described above is described in detail, so other details are not repeated here. Using methods 700 and 800 according to embodiments of the present disclosure, the range of blind detection of a downlink control channel associated with a terminal device can be reduced, and the complexity of blind detection can also be reduced. At the same time, using a downlink control channel structure based on a single carrier, low PAPR and better coverage can be achieved.

[0087] Figure 9 is a simplified block diagram of a device 900 suitable for implementing embodiments of the present disclosure. The device 900 may be considered as another exemplary implementation of the network device 110 or the terminal device 120 as shown in Figure 1 FIG. Thus, the device 900 may be implemented at the first network device 110 or the terminal device 120, or as at least a part of the first network device 110 or the terminal device 120.

[0088] As shown, the device 900 includes a processor 910, a memory 920 coupled to the processor 910, a suitable transmitter (TX) and receiver (RX) 940 coupled to the processor 910, and a communication interface coupled to the TX / RX 940. The memory 910 stores at least a part of a program 930. The TX / RX 940 is used for two-way communication. The TX / RX 940 has at least one antenna to facilitate communication, but in fact, the access nodes mentioned in this application may have several antennas. The communication interface may represent any interface required for communicating with other network elements, such as the X2 interface for two-way communication between eNBs, the S1 interface for communication between the mobility management entity (MME) / serving gateway (S-GW) and the eNB, the Un interface for communication between the eNB and the relay node (RN), or the Uu interface for communication between the eNB and the terminal device.

[0089] Assume that the program 930 includes program instructions that, when executed by the associated processor 910, cause the device 900 to operate according to embodiments of the present disclosure, as referred to herein Figures 1 to 8 as discussed. The embodiments herein may be implemented by computer software executable by the processor 910 of the device 900, or by hardware, or by a combination of software and hardware. The processor 910 may be configured to implement various embodiments of the present invention. In addition, the combination of the processor 910 and the memory 920 may form a processing component 950 suitable for implementing various embodiments of the present disclosure.

[0090] The memory 920 can be of any type suitable for the local technical network and can be implemented using any suitable data storage technology. By way of non-limiting example, such as a non-transitory computer-readable storage medium, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Although only one memory 920 is shown in the device 900, there can be several physically distinct memory modules in the device 900. By way of non-limiting example, the processor 910 can be of any type suitable for the local technical network and can include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 900 can have multiple processors, such as application-specific integrated circuit chips that are subordinate in time to a clock that synchronizes with the main processor.

[0091] In general, the various embodiments of the present disclosure can be implemented in hardware or in special-purpose circuits, software, logic, or any combination thereof. Some aspects can be implemented in hardware, while other aspects can be implemented in firmware or software, which can be executed by a controller, a microprocessor, or other computing devices. Although aspects of the embodiments of the present disclosure are shown and described as block diagrams, flowcharts, or using some other graphical representation, it will be understood that the blocks, devices, systems, techniques, or methods described herein can be implemented in, by way of non-limiting example, hardware, software, firmware, special-purpose circuits or logic, general-purpose hardware or controllers, or other computing devices, or some combination thereof.

[0092] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, that are executed in a device on a target real or virtual processor to perform the processes or methods described above with reference to Figures 6 to 1 1. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The functions of the program modules can be combined or separated as needed in various embodiments. The machine-executable instructions of the program modules can be executed within local or distributed devices. In a distributed device, the program modules can be located in both local storage media and remote storage media.

[0093] The program code for performing the methods of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the program codes are executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program codes can be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0094] The above program code can be embodied on a machine-readable medium, which can be any tangible medium that can contain or store a program used by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium can include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of the machine-readable storage medium will include: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0095] Furthermore, although the operations are described in a particular order, this should not be construed as requiring that the operations be performed in the particular order shown or in sequential order, or that all of the illustrated operations be performed, to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these details should not be construed as limiting the scope of the present disclosure, but rather as descriptions of features specific to particular embodiments. Certain features described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented separately or in any suitable sub-combination in multiple embodiments.

[0096] Although the present disclosure has been described in terms of structural features and / or method acts specific thereto, it should be understood that the present disclosure defined in the appended claims is not necessarily limited to the above specific features or acts. Rather, the above specific features and acts are disclosed as example forms for implementing the claims.

Claims

1. A communication method, comprising: generating a sequence of the reference signal for a channel including control information based on an initial value of the sequence of the reference signal; transmitting the reference signal to a terminal device via a first resource and transmitting the channel to the terminal device via a second resource; wherein: the initial value of the sequence of the reference signal is determined based on a parameter associated with the channel, and the parameter is associated with a cyclic redundancy check (CRC) corresponding to the control information.

2. The method according to claim 1, wherein the first resource is selected from a set of first resources, and the set of first resources is allocated for transmission of the reference signal.

3. The method according to claim 1, wherein the second resource is selected from a set of second resources, and the set of second resources is allocated for the channel.

4. The method according to claim 1, wherein the parameter includes at least one of the following: an aggregation level of the channel, a starting index of a control channel element for the channel, an index of the second resource, an index of a search space associated with the channel, and an index of a set of search spaces associated with the channel.

5. The method according to claim 1, wherein the reference signal is a demodulation reference signal (DMRS).

6. The method according to claim 1, wherein the reference signal is a channel state information reference signal (CSI-RS).

7. The method according to claim 1, wherein the first resource is time-division multiplexed with the second resource.

8. A communication method, comprising: at a terminal device, receiving a reference signal for a channel including control information via a first resource and receiving the channel via a second resource; wherein: the reference signal is determined based on an initial value of the sequence of the reference signal; and the initial value of the sequence of the reference signal is determined based on a parameter associated with the channel, and the parameter is associated with a cyclic redundancy check (CRC) corresponding to the control information.

9. The method according to claim 8, wherein the first resource is selected from a set of first resources, and the set of first resources is allocated for transmission of the reference signal.

10. The method according to claim 8, wherein the first resource is time-division multiplexed with the second resource.

11. The method according to claim 8, wherein the parameter includes at least one of the following: an aggregation level of the channel, a starting index of a control channel element for the channel, an index of the second resource, an index of a search space associated with the channel, and an index of a set of search spaces associated with the channel.

12. The method according to claim 8, wherein the reference signal is a demodulation reference signal (DMRS).

13. The method according to claim 8, wherein the reference signal is a channel state information reference signal (CSI-RS).

14. A communication device, comprising a processor configured to cause the device: Generate the sequence of the reference signal for a channel including control information based on an initial value of the sequence of the reference signal Transmit the reference signal to a terminal device via a first resource and transmit the channel to the terminal device via a second resource wherein the initial value of the sequence of the reference signal is determined based on a parameter associated with the channel, and the parameter is associated with a cyclic redundancy check (CRC) corresponding to the control information 15. The apparatus according to claim 14, wherein the reference signal is a demodulation reference signal (DMRS).

16. The apparatus according to claim 14, wherein the reference signal is a channel state information reference signal (CSI-RS).

17. A terminal device, comprising a processor configured to cause the device to receive a reference signal for a channel including control information via a first resource and receive the channel via a second resource wherein the reference signal is determined based on an initial value of a sequence of the reference signal and the initial value of the sequence of the reference signal is determined based on a parameter associated with the channel, and the parameter is associated with a cyclic redundancy check (CRC) corresponding to the control information 18. The terminal device according to claim 17, wherein the reference signal is a demodulation reference signal (DMRS).

19. The terminal device according to claim 17, wherein the reference signal is a channel state information reference signal (CSI-RS).

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