Communication method and communication apparatus

Abstract

Provided in the present application are a communication method and a communication apparatus. The method comprises: on the basis of a cyclic difference set, determining a first frequency domain resource index set and a second frequency domain resource index set; and on the basis of the first frequency domain resource index set and the second frequency domain resource index set, determining a first group of frequency domain resources used for transmitting a plurality of reference signals by means of a first antenna, and determining a second group of frequency domain resources used for transmitting a plurality of reference signals by means of a second antenna. In this way, on the basis of the cyclic difference set, the present application determines frequency domain resources for transmitting reference signals by means of each antenna, so as to reduce the interference between different antennas, thus resulting in low resource overhead and satisfying the requirements of communication scenarios and channel conditions. The solution of determining frequency domain resources for reference signals on the basis of a cyclic difference set is a compressed sensing channel estimation algorithm, uses the characteristics of channel sparsity, and thus can effectively restore channel responses with lower pilot overhead, thereby achieving better channel performance.

Description

Communication method and communication apparatus

[0001] The present application claims priority to the Chinese patent application No. 202410857559.X, filed on June 27, 2024, and entitled “Communication method and communication apparatus”, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] Embodiments of the present disclosure mainly relate to the field of communication, and more particularly, to a communication method and a communication apparatus. BACKGROUND

[0003] Orthogonal Frequency Division Multiplexing (OFDM) technology is widely used in wireless communication systems because of its strong anti-frequency selective fading performance and high spectral efficiency. Multi-Input Multi-Output (MIMO) is a technology that uses multiple antennas to transmit and receive signals.

[0004] In order to accurately recover the information of the signal at the receiving end, channel estimation is needed, for example, the transmitting end can send reference signals for the receiving end to perform channel estimation. However, due to the mutual interference between multiple antennas, how to effectively transmit reference signals through multiple antennas is one of the problems to be solved. SUMMARY

[0005] The present disclosure provides a transmission scheme for reference signals of multiple antennas, which determines the frequency domain resources of the reference signals transmitted by each antenna based on a cyclic difference set, thereby reducing the interference between different antennas.

[0006] In a first aspect of the present disclosure, a communication method is provided. The method comprises: determining a first set of frequency domain resource indexes and a second set of frequency domain resource indexes based on a cyclic difference set; and determining a first set of frequency domain resources for transmitting a plurality of reference signals through a first antenna and a second set of frequency domain resources for transmitting the plurality of reference signals through a second antenna based on the first set of frequency domain resource indexes and the second set of frequency domain resource indexes. In this way, the frequency domain resources of the reference signals transmitted by each antenna are determined based on a cyclic difference set, thereby reducing the interference between different antennas, having small resource overhead, and meeting the requirements of communication scenarios and channel conditions. The frequency domain resource determination scheme of the reference signals based on the cyclic difference set belongs to the compressed sensing channel estimation algorithm, which takes advantage of the sparsity of the channel to effectively recover the channel response with low pilot overhead, thereby achieving better channel performance.

[0007] In some implementations of the first aspect, the method further includes determining a cyclic difference set from the plurality of candidate difference sets based on the number of frequency domain resources and the number of reference signals. In this way, a cyclic difference set corresponding to the number of frequency domain resources can be selected, and further, values in the cyclic difference set can be mapped to indices of the frequency domain resources in order to further determine the frequency domain resources for transmitting the reference signals.

[0008] In some implementations of the first aspect, determining the cyclic difference set from the plurality of candidate difference sets includes determining a first candidate difference set from the plurality of candidate difference sets as the cyclic difference set if an absolute value of a difference between a first parameter of the first candidate difference set and the number of frequency domain resources is smaller than an absolute value of a difference between a first parameter of any candidate difference set from the plurality of candidate difference sets other than the first candidate difference set and the number of frequency domain resources. In some implementations of the first aspect, determining the cyclic difference set from the plurality of candidate difference sets includes, if a first parameter of a second candidate difference set from the plurality of candidate difference sets is equal to a first parameter of a third candidate difference set from the plurality of candidate difference sets, and an absolute value of a difference between the first parameter of the second candidate difference set and the number of frequency domain resources is smaller than an absolute value of a difference between a first parameter of any candidate difference set from the plurality of candidate difference sets other than the second candidate difference set and the third candidate difference set and the number of frequency domain resources, comparing a second parameter of the second candidate difference set with a second parameter of the third candidate difference set, and determining the second candidate difference set as the cyclic difference set if an absolute value of a difference between the second parameter of the second candidate difference set and the number of reference signals is smaller than an absolute value of a difference between the second parameter of the third candidate difference set and the number of reference signals. In this way, a cyclic difference set that matches the number of frequency domain resources and / or the number of reference signals can be determined.

[0009] In some implementations of the first aspect, an intersection of any two sets from the plurality of sets of cyclic difference sets is the same, and wherein the plurality of sets includes a first set of frequency domain resource indices and a second set of frequency domain resource indices. In this way, sets of frequency domain resource indices can be determined based on the intersection group whose intersections are all the same, such that in a multi-antenna scenario, an increase in overlapping resources as the number of antennas increases can be avoided.

[0010] In some implementations of the first aspect, determining the first set of frequency domain resources and the second set of frequency domain resources includes determining an intersection of the first set of frequency domain resource indexes and the second set of frequency domain resource indexes, determining the set of indexes of the plurality of frequency domain resources in the first set of frequency domain resources includes a portion of the first set of frequency domain resource indexes excluding the intersection and a portion of the intersection, and determining the set of indexes of the plurality of frequency domain resources in the second set of frequency domain resources includes a portion of the second set of frequency domain resource indexes excluding the intersection and a remaining portion of the intersection. In this way, the first set of frequency domain resource indexes and the second set of frequency domain resource indexes can be selected based on the characteristic that the intersection is the same between each pair. For a multi-antenna scenario, the location of the overlapping frequency domain resources is fixed, so that the performance of channel estimation under multiple antennas does not degrade as the number of antennas increases. Also, by using different portions of the intersection for different antennas, the frequency domain resources used by each antenna for transmitting reference signals do not overlap, so that the performance of channel estimation is similar to that of a single antenna, the processing at the transmitting end and the receiving end is simple, and the scheme can support a larger number of antennas.

[0011] In some implementations of the first aspect, an absolute value of a difference between a number of indexes in the portion of the intersection and a number of indexes in the remaining portion of the intersection is less than a preset threshold. In this way, the overlapping indexes in the intersection can be evenly or approximately evenly allocated to each antenna to meet the requirements of each channel condition.

[0012] In some implementations of the first aspect, determining the first set of frequency domain resources and the second set of frequency domain resources includes determining an intersection of the first set of frequency domain resource indexes and the second set of frequency domain resource indexes, wherein the intersection includes at least a first index, determining the set of indexes of the plurality of frequency domain resources in the first set of frequency domain resources includes the first set of frequency domain resource indexes and a second index adjacent to the first index, and determining the set of indexes of the plurality of frequency domain resources in the second set of frequency domain resources includes the second set of frequency domain resource indexes and the second index. Exemplarily, a first set of orthogonal codes for a first antenna and a second set of orthogonal codes for a second antenna are determined for reference signals to be transmitted on frequency domain resources of the first index and the second index, respectively. In this way, the frequency domain resources corresponding to the overlapping indexes in the intersection can be code-division using Orthogonal Cover Code (OCC), which is better for a partial code-division scheme when the frequency domain channel changes slowly, and the channel information is more complete.

[0013] In some implementations of the first aspect, the first set of frequency domain resource indices has no intersection with the second set of frequency domain resource indices, and wherein the set of indices of the plurality of frequency domain resources in the first group of frequency domain resources is the first set of frequency domain resource indices, and the set of indices of the plurality of frequency domain resources in the second group of frequency domain resources is the second set of frequency domain resource indices. In this way, by determining the sets for the plurality of antennas to have no intersection in the frequency domain, the channel estimation performance for the multiple antennas can be guaranteed to be the same as that for a single antenna.

[0014] In some implementations of the first aspect, the cyclic difference set is determined from the plurality of candidate difference sets based on the number of frequency domain resources and the number of reference signals, wherein a first parameter of the cyclic difference set is smaller than a first parameter of any candidate difference set in the plurality of candidate difference sets other than the cyclic difference set by an absolute value of a difference between the number of frequency domain resources and half of the number of frequency domain resources. In this way, the cyclic difference set can be selected according to half of the number of frequency domain resources, so that the range of frequency domain resources for which the scheme utilizing the cyclic difference set can be applied is larger, and the scope of application is wider.

[0015] In some implementations of the first aspect, determining the first set of frequency domain resource indices and the second set of frequency domain resource indices comprises: mapping each value in a first set of the plurality of sets of the cyclic difference set to two frequency domain resource indices to obtain the first set of frequency domain resource indices; and mapping each value in a second set of the plurality of sets of the cyclic difference set to two frequency domain resource indices to obtain the second set of frequency domain resource indices. Exemplarily, a value i in the first set corresponds to indices 2i-1 and 2i in the first set of frequency domain resource indices, where i is a positive integer, and a value j in the second set corresponds to indices 2j-1 and 2j in the second set of frequency domain resource indices, where j is a positive integer. In this way, by the one-to-two mapping, the cyclic difference set can be mapped to the frequency domain resources.

[0016] In some implementations of the first aspect, the set of indices of the plurality of frequency domain resources in the first group of frequency domain resources is the first set of frequency domain resource indices, and the set of indices of the plurality of frequency domain resources in the second group of frequency domain resources is the second set of frequency domain resource indices. In this way, the OCC can be further utilized for different antenna frequency domain coding.

[0017] In some implementations of the first aspect, the method further comprises: transmitting, by the first antenna, the plurality of reference signals on the first group of frequency domain resources; and transmitting, by the second antenna, the plurality of reference signals on the second group of frequency domain resources. In this way, the reference signals can be transmitted by at least two antennas at the transmitting end.

[0018] In some implementations of the first aspect, the method further includes receiving, by the first antenna, the plurality of reference signals on the first set of frequency domain resources, receiving, by the second antenna, the plurality of reference signals on the second set of frequency domain resources, and performing channel estimation based on the reference signal reception values by the first antenna and the reference signal reception values by the second antenna. In this way, the reference signals can be received by at least two antennas at the receiving end, and channel estimation can be performed based thereon.

[0019] In some implementations of the first aspect, the method further includes receiving, by the first antenna, the plurality of reference signals on the first set of frequency domain resources, receiving, by the second antenna, the plurality of reference signals on the second set of frequency domain resources, determining an equivalent channel reception value based on the reference signal reception values by the first antenna and the reference signal reception values by the second antenna, and performing channel estimation based on the equivalent channel reception value using an Orthogonal Matching Pursuit (OMP) algorithm. In this way, the reference signals can be received by at least two antennas at the receiving end, and channel estimation can be further performed using the OMP algorithm, avoiding additional operations of interpolation based on the equivalent channel, thereby saving computing resources and improving processing efficiency.

[0020] In a second aspect of the present disclosure, a communication apparatus is provided. The apparatus includes an index set determination module configured to determine a first set of frequency domain resource indexes and a second set of frequency domain resource indexes based on a cyclic difference set, and a resource determination module configured to determine a first set of frequency domain resources for transmitting a plurality of reference signals by a first antenna and a second set of frequency domain resources for transmitting the plurality of reference signals by a second antenna based on the first set of frequency domain resource indexes and the second set of frequency domain resource indexes.

[0021] In a third aspect of the present disclosure, a communication apparatus is provided. The apparatus includes one or more processors configured to determine a first set of frequency domain resource indexes and a second set of frequency domain resource indexes based on a cyclic difference set, and determine a first set of frequency domain resources for transmitting a plurality of reference signals by a first antenna and a second set of frequency domain resources for transmitting the plurality of reference signals by a second antenna based on the first set of frequency domain resource indexes and the second set of frequency domain resource indexes.

[0022] In some implementations, the apparatus further includes a memory having instructions stored thereon for execution by the one or more processors, the instructions, when executed by the one or more processors, causing the apparatus to implement the method as described in the first aspect or any implementation of the first aspect.

[0023] In a fourth aspect of the present disclosure, a computer-readable storage medium is provided, having stored thereon computer-executable instructions that, when executed by a processor, implement the operations of the method according to the first aspect above or any implementation thereof.

[0024] In a fifth aspect of the present disclosure, a chip or chip system is provided. The chip or chip system comprises processing circuitry configured to perform the operations of the method according to the first aspect above or any implementation thereof.

[0025] In a sixth aspect of the present disclosure, a computer program or computer program product is provided. The computer program or computer program product is tangibly stored on a computer-readable medium and includes computer-executable instructions that, when executed, implement the operations of the method according to the first aspect above or any implementation thereof.

[0026] It should be understood that the technical effects in the first aspect and its various implementations are equally applicable to each of the second to sixth aspects, and thus the technical effects of the second to sixth aspects are not repeatedly described herein.

[0027] It should be understood that the content described in the summary section is not intended to define key or important features of the embodiments of the present disclosure, nor to limit the scope of the present disclosure. Other features of the present disclosure will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above and other features, advantages, and aspects of embodiments of the present disclosure will become more apparent by describing in detail some example embodiments with reference to the attached drawings.

[0029] In the drawings, the same or similar reference numerals designate the same or similar elements, wherein:

[0030] FIG. 1 shows a schematic diagram of a system in which embodiments of the present disclosure can be implemented;

[0031] FIG. 2 shows a schematic flowchart of a communication process according to some example embodiments of the present disclosure;

[0032] FIG. 3 shows a schematic diagram of a mapping between values in a set of cyclic difference sets and frequency domain resource indices according to some example embodiments of the present disclosure;

[0033] FIG. 4 shows a schematic diagram of comparison results between a multi-antenna scheme of Singer cyclic difference set shift groups according to embodiments of the present disclosure and a plurality of existing schemes;

[0034] FIG. 5 shows a schematic diagram of comparison results between a partial code division multi-antenna scheme according to embodiments of the present disclosure and a plurality of existing schemes;

[0035] FIG. 6 shows a schematic diagram of results of a full disjoint set based multi-antenna scheme according to an embodiment of the present disclosure;

[0036] FIG. 7 shows a schematic diagram of comparison results between a full code division based multi-antenna scheme and existing schemes according to an embodiment of the present disclosure;

[0037] FIG. 8 shows a schematic flowchart of a communication method according to an embodiment of the present disclosure;

[0038] FIG. 9 shows a schematic block diagram of an apparatus for communication according to some embodiments of the present disclosure; and

[0039] FIG. 10 shows a schematic block diagram of an example device that can be used to implement embodiments of the present disclosure. DETAILED DESCRIPTION

[0040] Embodiments of the present disclosure will be described in more detail with reference to the drawings. While certain embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be embodied in various forms and should not be interpreted as being limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure can be more thoroughly and completely understood. It will be appreciated that the drawings of the present disclosure are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

[0041] In the description of embodiments of the present disclosure, the term "includes" and its derivatives, are not intended to be limiting of the disclosure. The term "based on" is intended to be back- ended "based, at least in part on." The term "one embodiment" or "an embodiment" are intended to be interpreted as "at least one embodiment." The term "first," "second," and the like are intended to be interpreted as "different or similar" unless otherwise indicated. The term "and / or" means at least one of the items it connects. For example, "A and / or B" means A, B, or A and B. Other explicit and implicit definitions can also be included below.

[0042] In embodiments of the present disclosure, "a plurality of" means at least two, i.e., two or more, unless explicitly stated otherwise.

[0043] Embodiments of the present disclosure relate to the term “reference signal”, which can also be referred to as “pilot” in some examples. The reference signal in the present disclosure can be an uplink reference signal, a downlink reference signal, or a sidelink reference signal. It can be understood that the present disclosure does not limit the specific type of reference signal, which can include but is not limited to: De-Modulation Reference Signal (DMRS), Tracking Reference Signal (TRS), Phase Track Reference Signal (PT-RS), Channel State Information Reference Signal (CSI-RS), Cell Reference Signal (CRS), Positioning Reference Signal (PRS), Sounding Reference Signal (SRS), or other types or other names of reference signals defined in future communication standards or communication protocols.

[0044] Embodiments of the present disclosure relate to the term “frequency domain resource”, which can represent a unit of resource in the frequency domain. The frequency domain resource in the present disclosure can be in a licensed frequency band or an unlicensed frequency band, and can be within frequency range 1 (FR1) or frequency range 2 (FR2). The present disclosure does not limit the specific form of the frequency domain resource, which can include but is not limited to: Physical Resource Block (PRB), Virtual Resource Block (VRB), Resource Block (RB), Resource Element (RE), subcarrier (or tone), or other types or other names of frequency domain resources defined in future communication standards or communication protocols.

[0045] Orthogonal Frequency Division Multiplexing (OFDM) technology uses orthogonal sub-carrier signals to transmit data in parallel, has strong performance in resisting frequency selective fading and high spectrum efficiency, and is widely used in wireless communication systems, for example, has become one of the core technologies of communication systems. In order to accurately recover the information of the signal at the receiving end, channel estimation is needed. Generally, the channel estimation methods include pilot-assisted channel estimation, semi-blind channel estimation, and blind channel estimation, among which pilot-assisted channel estimation is a commonly used method.

[0046] The pilot-assisted channel estimation uses the strategy of mixing pilot and data frequency points within a symbol. For frequency domain estimation, the channel frequency response of each pilot point is first estimated, and the channel frequency response estimation of other pilot points is realized by interpolation calculation of different methods. For time domain estimation, the time domain separable path gain is first estimated, and then the frequency domain channel transmission matrix applied to data detection is obtained by fast Fourier transform. The frequency domain estimation and the time domain estimation generally use the least square method or the minimum mean square error method to realize channel estimation.

[0047] In pilot-assisted channel estimation, pilot symbols need to be inserted at the sending end, and the pilot is used for channel estimation at the receiving end. In high-speed broadband communication, the channel usually has sparsity, and the compressed sensing technology can accurately recover the sparse signal by using less sampling information, so the channel estimation scheme based on compressed sensing can effectively reduce the pilot overhead.

[0048] In the least square (LS), minimum mean square error (MMSE) and other channel estimation schemes, a uniform pilot placement method is generally used, such as forming a comb-shaped or block-shaped pilot. For example, the comb-shaped pilot is more suitable for fast fading channels. The comb-shaped pilot placement scheme places the pilot continuously in the time domain and uniformly in the frequency domain. Channel estimation is usually performed in an OFDM symbol, and after the channel response at the pilot is obtained, interpolation is performed in the frequency domain to obtain the channel response at the data. For example, assuming that the pilot placement period in the frequency domain is T f , the maximum delay spread is σ max , and the frequency selectivity of the channel satisfies the following formula (1):

[0049] However, the comb-shaped pilot is uniformly placed in the frequency domain, and this scheme can achieve optimal performance based on traditional LS, MMSE and other channel estimation algorithms, but these traditional channel estimation algorithms will waste a large amount of spectrum and pilot resources.

[0050] In the OFDM channel estimation based on the compressed sensing, the non-uniformly distributed pilot pattern can be the best. In combination with the sparsity of the channel, the channel estimation is performed by using the compressed sensing technology, the channel response of the entire OFDM symbol can be accurately recovered by using less pilot resources, which well solves the problem of signal overhead. For example, the best pilot pattern can be found based on the non-deterministic random pilot, or by using the exhaustive search, random search, etc. However, this scheme has high complexity and is difficult to converge, and is not suitable for the actual communication system, and is not easy to extend to the multi-antenna system.

[0051] Therefore, the present disclosure provides a scheme for determining the frequency domain resource of the reference signal. In the scheme, for the multi-antenna system, the frequency domain resource of the reference signal transmitted by each antenna is determined, and the interference between different antennas is small. In this way, a suitable pilot pattern can be determined, and better channel estimation performance can be obtained. The embodiments of the present disclosure will be described in detail below in combination with the drawings.

[0052] FIG. 1 shows a schematic diagram of a system 100 in which the embodiments of the present disclosure can be implemented. In the system 100, network devices 110-1 and 110-2 (collectively or individually referred to as network devices 110), and terminal devices 120-1 and 120-2 (collectively or individually referred to as terminal devices 120) are included. The network devices 110 and the terminal devices 120 can communicate with each other, for example, the network device 110-1 can provide network access services for the terminal device 120-1 and the terminal device 120-2.

[0053] The network device 110, or a radio access network (RAN) device, can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in a 5th generation (5G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system, etc. The network device 110 can also be a module or unit that completes part of the functions of a base station, for example, can be a central unit (CU) or a distributed unit (DU). The CU can complete the functions of the radio resource control protocol and the packet data convergence protocol (PDCP) of the base station, and can also complete the function of the service data adaptation protocol (SDAP). The DU can complete the functions of the radio link control layer and the medium access control (MAC) layer of the base station, and can also complete part or all of the functions of the physical layer. For specific descriptions of the above-mentioned protocol layers, reference can be made to the relevant technical specifications of the 3rd generation partnership project (3GPP). The radio access network device can be a macro base station, or a micro base station or an indoor station, or a relay node or a donor node, etc. The embodiments of the present disclosure do not limit the specific technologies and specific device forms adopted by the radio access network device.

[0054] The terminal device 120, which can also be referred to as a terminal, a user equipment (UE), a mobile station, a mobile terminal, etc. The terminal device 120 can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, a wireless modem, a computing device or other processing device connected to a wireless modem, an augmented reality (AR) device, a virtual reality (VR) device, an artificial intelligence (AI) device, etc. It can also include a subscriber unit, a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA) computer, a tablet computer, a netbook, a handheld device, a laptop computer, a cordless phone, or a wireless local loop (WLL) station, a machine type communication (MTC) terminal, or a relay user equipment, etc. For example, the relay user equipment can be a residential gateway (RG).

[0055] The terminal device 120 can be widely applied to various scenarios, such as device-to-device (D2D) communication, vehicle to everything (V2X) communication, machine-type communication (MTC), internet of things (IOT), virtual reality, augmented reality, industrial control, automatic driving, remote medical treatment, smart power grid, smart home, smart office, smart wear, smart transportation, smart city, etc.

[0056] Embodiments of the present disclosure can be implemented according to any appropriate communication protocol, including but not limited to, a third generation (3G), fourth generation (4G), fifth generation (5G), or future cellular communication protocol, a wireless local area network communication protocol such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or any other protocol that is presently known or that is developed in the future. The technical solutions of embodiments of the present disclosure apply to a communication system that follows any appropriate communication protocol, for example, a General Packet Radio Service (GPRS) system, a Global System for Mobile Communications (GSM) system, an Enhanced Data rate for GSM Evolution (EDGE) system, a Universal Mobile Telecommunications system (UMTS) system, a Long Term Evolution (LTE) system, a Wideband Code Division Multiple Access (WCDMA) system, a Code Division Multiple Access 2000 (CDMA2000) system, a Time Division-Synchronization Code Division Multiple Access (TD-SCDMA) system, a Frequency Division Duplex (FDD) system, a Time Division Duplex (TDD) system, a fifth generation system or a New Radio (NR) system, a future evolved generation communication system, and / or the like.

[0057] In the embodiments of this disclosure, network device 110 and terminal device 120 may have multiple antennas. The embodiments of this disclosure can be applied to communication between network devices, such as communication between network device 110-1 and network device 110-2, or to communication between terminal devices, such as communication between terminal device 120-1 and terminal device 120-2, or to communication between network devices and terminal devices, such as communication between network device 110-1 and terminal device 120-1, and so on. For ease of description, some embodiments below are illustrated using two or four antennas as examples. However, it should be understood that the embodiments of this disclosure can also be applied to scenarios with other numbers of antennas, such as network device 110 or terminal device 120 having 2 antennas, 4 antennas, or 8 antennas, etc. This disclosure is not limited in this respect.

[0058] It should be understood that the system 100 shown in Figure 1 is merely illustrative, and the embodiments of this disclosure can also be applied to other scenarios. For example, the terminal device 120 and the network device 110 can communicate directly or can perform multi-hop transmission via other relay devices. For example, the terminal device 120 can be in a dual-connection or multi-connection scenario. Furthermore, it should be understood that although two network devices 110 and two terminal devices 120 are shown in the scenario depicted in Figure 1, the embodiments of this disclosure are not limited thereto. For example, the system 100 may include more or fewer devices.

[0059] The embodiments of this disclosure relate to a "Cyclic Difference Set," also simply called a difference set, which is a symmetric balanced incomplete block design with cyclic properties. Codes constructed using cyclic differences exhibit cyclic characteristics. A cyclic difference set can be represented by three parameters, such as (v, k, λ). Specifically, a group G of size v is cyclic, and a subset of this group G is represented as D = {d1, d2, ..., dk}. k Furthermore, every non-zero element g∈G of the group G can be represented in λ different ways, for example, g=d i -d j As can be seen, in the cyclic difference set (v,k,λ), v represents the size of G, k represents the size of D, and λ represents the number of ways each non-zero element of G can be represented. The difference set in this embodiment can be a circumferential difference set or a Singer cyclic difference set.

[0060] Assume e and f are positive integers, p = e * f + 1 is a prime number, and α is a finite field. The fundamental element can be defined by the following equation (2): C i ={α ej+i :0≤j <f},0≤i<e-1, (2)

[0061] Then C i is called cyclotomic class of order e and has

[0062] Let p≥2 be a prime, r≥1, d≥2, q=p r , α be a primitive element of the finite field , Tr be the trace function from to , the following formula (3) can be defined: D0={0≤t<v:Tr(α t )=0}, (3)

[0063] Then D0 is a Singer cyclic difference set with parameters (v, k, λ) and satisfies:

[0064] A Singer cyclic difference set has three parameters, which are v, k and λ. In some examples, a Singer cyclic difference set can be represented as D0 with parameters (v, k, λ), where D0 is a set or a subset including multiple arrays. For example, a Singer cyclic difference set can be represented as D0(v, k, λ), or simply (v, k, λ). By cyclically shifting the Singer cyclic difference set D0, multiple sets after cyclic shift can be obtained. Generally, the intersection between any two of the different sets obtained by cyclic shift is also generally not the same. Further, from the multiple sets after cyclic shift, an intersection group (also referred to as a shift group) can be determined, such that the intersection of any two sets in the intersection group is the same. Specifically, the intersection group can be represented as Q k ={D i ,D a ,D b ,…}, where any set in the intersection group can be obtained by cyclically shifting the Singer difference set D0, and satisfies: D i ∩D a =D i ∩D b =D a ∩D b =…=D i ∩D j =A ij (5)

[0065] Exemplary embodiments of the present disclosure will be described in more detail below with reference to FIG. 2. FIG. 2 shows a schematic flowchart of a communication process 200 according to some example embodiments of the present disclosure. The process 200 involves a first device 201 and a second device 202. For convenience of expression, the first device 201 can be a transmitting device and the second device 202 can be a receiving device. In connection with the system 100 of FIG. 1, the first device 201 can be a network device 110 or a terminal device 120, and the second device 202 can be a network device 110 or a terminal device 120 different from the first device 201. For example, the first device 201 is the network device 110-1 and the second device 202 is the network device 110-2 or the terminal device 120-1. For another example, the first device 201 is the terminal device 120-1 and the second device 202 is the network device 110-1 or the terminal device 120-2.

[0066] At operation 220 of the process 200, the first device 201 determines a first set of frequency domain resource indices and a second set of frequency domain resource indices based on the cyclic difference set. Further, at operation 240, the first device 201 can determine a first group of frequency domain resources for transmitting the plurality of reference signals through the first antenna and a second group of frequency domain resources for transmitting the plurality of reference signals through the second antenna based on the first set of frequency domain resource indices and the second set of frequency domain resource indices.

[0067] Additionally or alternatively, the first device 201 can determine the cyclic difference set at operation 210. In some embodiments, the determined cyclic difference set can be a cyclotomic difference set as described before or a Singer cyclic difference set or another type of cyclic difference set.

[0068] In some implementations of the present disclosure, the determined cyclic difference set is a Singer cyclic difference set. In some examples, the cyclic difference set can be selected (or determined) from a plurality of candidate difference sets. In some embodiments, the plurality of candidate difference sets can be a plurality of Singer cyclic difference sets, for example including some or all of the following Table 1.

[0069] Table 1

[0070] In some examples, the cyclic difference set can be selected based on the number of frequency domain resources and the number of reference signals. In this way, the cyclic difference set corresponding to the number of frequency domain resources can be selected, and then the values in the cyclic difference set can be mapped to the indices of the frequency domain resources, so as to further determine the frequency domain resources used for transmitting the reference signals. For the convenience of description, it can be assumed that the number of frequency domain resources is N, the number of reference signals is Np, Np < N, and both are positive integers. In some examples, the candidate difference set with the first parameter (i.e., v) closest to the number of frequency domain resources (i.e., N) can be selected as the cyclic difference set. For example, if N = 585, (585, 73, 9) can be selected from the plurality of candidate difference sets in Table 1. Alternatively, if there are two or more candidate difference sets with the first parameter (i.e., v) closest to the number of frequency domain resources (i.e., N), the candidate difference set with the second parameter (i.e., k) closest to the number of reference signals (i.e., Np) can be further selected as the cyclic difference set.

[0071] For example, if the absolute value of the difference between the first parameter (i.e., v) of the first candidate difference set in the plurality of candidate difference sets and the number of frequency domain resources (i.e., N) is less than the absolute value of the difference between the first parameter of any candidate difference set in the plurality of candidate difference sets other than the first candidate difference set and the number of frequency domain resources (i.e., N), the first candidate difference set is determined as the cyclic difference set. For example, if the first parameter (i.e., v) of the second candidate difference set in the plurality of candidate difference sets is equal to the first parameter (i.e., v) of the third candidate difference set in the plurality of candidate difference sets, and the absolute value of the difference between the first parameter of the second candidate difference set and the number of frequency domain resources (i.e., N) is less than the absolute value of the difference between the first parameter of any candidate difference set in the plurality of candidate difference sets other than the second candidate difference set and the third candidate difference set and the number of frequency domain resources (i.e., N), the second parameter of the second candidate difference set can be compared with the second parameter of the third candidate difference set; further, if the absolute value of the difference between the second parameter of the second candidate difference set and the number of reference signals (i.e., Np) is less than the absolute value of the difference between the second parameter of the third candidate difference set and the number of reference signals (i.e., Np), the second candidate difference set is determined as the cyclic difference set. In this way, the cyclic difference set matching the number of frequency domain resources and / or the number of reference signals can be determined.

[0072] In some examples of the disclosure, the cyclic difference set on which operation 220 is based can be a Singer cyclic difference set, such as one of the difference sets listed in Table 1. In some examples, the first set of frequency domain resource indices and the second set of frequency domain resource indices can be determined based on a cyclic shift of the Singer cyclic difference set. It should be noted that in a multi-antenna scenario, multiple sets of frequency domain resource indices corresponding to multiple antennas respectively can be determined based on the cyclic difference set at operation 220, specifically, assuming the number of antennas is Na, Na sets of frequency domain resource indices corresponding to the Na antennas one-to-one can be determined, for example, Na is any one of 2, 4, 8, etc.

[0073] For example, based on the Singer cyclic difference set, a set of intersections (i.e., Q k ) can be determined, and then Na sets of frequency domain resource indices can be selected from the set of intersections, for example, the first set of frequency domain resource indices and the second set of frequency domain resource indices are selected. As discussed above, the intersection of any two sets in the set of intersections (i.e., Q k ) is the same.

[0074] For example, the Singer cyclic difference set D0(v=585, k=73, λ=9) = {0, 19, 23, 35, 38, 46, 51, 59, 65, 70, 76, 92, 93, 97, 102, 118, 130, 131, 133, 140, 151, 152, 155, 159, 161, 179, 184, 185, 186, 191, 194, 195, 204, 231, 236, 260, 262, 266, 273, 280, 302, 304, 310, 318, 322, 325, 339, 341, 358, 359, 368, 370, 372, 373, 382, 385, 388, 390, 408, 429, 455, 462, 463, 472, 479, 485, 507, 520, 524, 532, 535, 546, 560}. The corresponding set of intersections is: k 10 11 44 65 103 318 408 422 (6)

[0075] That is, D0can be cyclically shifted by 1, 10, 11, 44, 65, 103, 318, 408, 422 positions respectively to obtain Q k ​​​​​​​​each set of the intersection group. Then, in embodiments of the present disclosure, a set of frequency domain resource indexes corresponding to each antenna can be selected from each set of the intersection group as shown in equation (6). Exemplarily, the values included in the set can represent the frequency domain resource indexes.

[0076] As a specific example, for a 4-antenna scenario, 4 sets D1, D k 2, D 10 3, and D 11 4 can be selected from the intersection group Q 44 Based on D0(v=585, k=73, λ=9) as above, D1, D 10 2, D 11 3, and D 44 4 can be represented as follows, respectively:

[0077] D1= {1, 20, 24, 36, 39, 47, 52, 60, 66, 71, 77, 93, 94, 98, 103, 119, 131, 132, 134, 141, 152, 153, 156, 160, 162, 180, 185, 186, 187, 192, 195, 196, 205, 232, 237, 261, 263, 267, 274, 281, 303, 305, 311, 319, 323, 326, 340, 342, 359, 360, 369, 371, 373, 374, 383, 386, 389, 391, 409, 430, 456, 463, 464, 473, 480, 486, 508, 521, 525, 533, 536, 547, 561},

[0078] D 10 2= {10, 29, 33, 45, 48, 56, 61, 69, 75, 80, 86, 102, 103, 107, 112, 128, 140, 141, 143, 150, 161, 162, 165, 169, 171, 189, 194, 195, 196, 201, 204, 205, 214, 241, 246, 270, 272, 276, 283, 290, 312, 314, 320, 328, 332, 335, 349, 351, 368, 369, 378, 380, 382, 383, 392, 395, 398, 400, 418, 439, 465, 472, 473, 482, 489, 495, 517, 530, 534, 542, 545, 556, 570},

[0079] D 11= {11, 30, 34, 46, 49, 57, 62, 70, 76, 81, 87, 103, 104, 108, 113, 129, 141, 142, 144, 151, 162, 163, 166, 170, 172, 190, 195, 196, 197, 202, 205, 206, 215, 242, 247, 271, 273, 277, 284, 291, 313, 315, 321, 329, 333, 336, 350, 352, 369, 370, 379, 381, 383, 384, 393, 396, 399, 401, 419, 440, 466, 473, 474, 483, 490, 496, 518, 531, 535, 543, 546, 557, 571},

[0080] D 44 = {5, 19, 44, 63, 67, 79, 82, 90, 95, 103, 109, 114, 120, 136, 137, 141, 146, 162, 174, 175, 177, 184, 195, 196, 199, 203, 205, 223, 228, 229, 230, 235, 238, 239, 248, 275, 280, 304, 306, 310, 317, 324, 346, 348, 354, 362, 366, 369, 383, 385, 402, 403, 412, 414, 416, 417, 426, 429, 432, 434, 452, 473, 499, 506, 507, 516, 523, 529, 551, 564, 568, 576, 579}.

[0081] And, the intersection between the four sets two by two is: A = {103, 141, 162, 195, 196, 205, 369, 383, 473}.

[0082] Further, at operation 240, for each of the plurality of antennas, a set of frequency domain resources through which a reference signal is transmitted by the antenna can be determined. For example, a first set of frequency domain resources for transmitting the plurality of reference signals through a first antenna and a second set of frequency domain resources for transmitting the plurality of reference signals through a second antenna can be determined.

[0083] In some embodiments, an intersection of the first set of frequency domain resource indices and the second set of frequency domain resource indices can be determined; then a set of indices of the plurality of frequency domain resources in the first group of frequency domain resources can include a part of the first set of frequency domain resource indices excluding the intersection and a part of the intersection; and a set of indices of the plurality of frequency domain resources in the second group of frequency domain resources can include a part of the second set of frequency domain resource indices excluding the intersection and a remaining part of the intersection. For example, an absolute value of a difference between a number of indices in the part of the intersection and a number of indices in the remaining part of the intersection is less than a preset threshold.

[0084] As discussed above, the intersection between the set of indices of the plurality of frequency domain resources for the plurality of antennas two by two is the same. The plurality of indices in the intersection correspond to frequency domain resources which can be overlapped for the plurality of antennas, and the overlapped frequency domain resources can cause interference between each other. In order to reduce the interference, in some examples, the intersection can include a plurality of indices, the plurality of indices can be divided into a plurality of parts corresponding to the plurality of antennas one by one, and the plurality of parts do not intersect with each other. Then, a group of frequency domain resources corresponding to a certain specific antenna can include a plurality of resources (for example, a plurality of REs or a plurality of subcarriers), and a set of indices of the plurality of resources includes a set of indices of the frequency domain resources corresponding to the specific antenna excluding those parts in the intersection corresponding to other antennas. In this way, different groups of frequency domain resources for different antennas do not intersect, thereby avoiding interference between different antennas. For convenience of expression, this scheme can be referred to as a Singer cyclic difference set shifted group multi-antenna scheme.

[0085] Optionally, the plurality of indices in the intersection can be divided equally or as equally as possible according to the number of antennas, so as to divide the plurality of indices in the intersection into Na parts. Then the Na parts can be respectively allocated to the Na antennas. For example, in the Na parts into which the intersection is divided, an absolute value of a difference between a number of indices in each two parts is less than a preset threshold. For example, the preset threshold can be related to the number of antennas, for example, Na-1. For example, the preset threshold is related to an allowable value of a performance difference between different antennas, for example, if a performance requirement of antenna A1 is higher than a performance requirement of antenna A2, then the part for antenna A1 can include more indices than the part for antenna A2. For example, the preset threshold can be a value related to resources, for example, can be related to a structure of the resources, etc.

[0086] In the specific example of 4 antennas given above, the plurality of indices in the intersection A can be divided into 4 parts corresponding to the 4 antennas, for example, according to the example shown in Table 2 as follows.

[0087] Table 2

[0088] In Table 2, "1" indicates that the reference signal is transmitted on the frequency domain resource corresponding to the index, and "0" indicates that the reference signal is not transmitted on the frequency domain resource corresponding to the index. It should be understood that only one example of allocating multiple indexes in the intersection is shown in Table 2, and embodiments of the present disclosure should also include other examples, for example, 2 indexes corresponding to the resources for antenna 1, for example, other 2 or three indexes in the intersection corresponding to the resources for antenna 1, and the like, which will not be listed one by one here.

[0089] Based on this example, 4 groups of frequency domain resources corresponding to 4 antennas can be determined. For example, the set of indexes of the first group of frequency domain resources for antenna 1 includes D1 excluding 195, 196, 205, 369, 383, 473 described above. For example, the set of indexes of the second group of frequency domain resources for antenna 2 includes D1 excluding 103, 141, 162, 205, 369, 383, 473 described above. For example, the set of indexes of the third group of frequency domain resources for antenna 3 includes D1 excluding 103, 141, 162, 195, 196, 383, 473 described above. For example, the set of indexes of the fourth group of frequency domain resources for antenna 4 includes D1 excluding 103, 141, 162, 195, 196, 205, 369 described above. 10 excluding 103, 141, 162, 205, 369, 383, 473 described above. For example, the set of indexes of the third group of frequency domain resources for antenna 3 includes D1 excluding 103, 141, 162, 195, 196, 383, 473 described above. For example, the set of indexes of the fourth group of frequency domain resources for antenna 4 includes D1 excluding 103, 141, 162, 195, 196, 205, 369 described above. 11 excluding 103, 141, 162, 205, 369, 383, 473 described above. For example, the set of indexes of the third group of frequency domain resources for antenna 3 includes D1 excluding 103, 141, 162, 195, 196, 383, 473 described above. For example, the set of indexes of the fourth group of frequency domain resources for antenna 4 includes D1 excluding 103, 141, 162, 195, 196, 205, 369 described above. 44 excluding 103, 141, 162, 205, 369, 383, 473 described above. For example, the set of indexes of the third group of frequency domain resources for antenna 3 includes D1 excluding 103, 141, 162, 195, 196, 383, 473 described above. For example, the set of indexes of the fourth group of frequency domain resources for antenna 4 includes D1 excluding 103, 141, 162, 195, 196, 205, 369 described above.

[0090] In some embodiments, the corresponding set of frequency domain resource indexes can be determined as the corresponding antenna. However, it can be understood that since the reference signal transmission between multiple antennas needs to be orthogonal in the frequency domain, there is an intersection between any two sets, that is, there is an overlapping position in the frequency domain, so some positions in the frequency domain of different antennas will interfere with each other. In embodiments of the present disclosure, since the set of frequency domain resource indexes is selected from the intersection group of Singer cyclic difference sets, the intersection of any two sets in the intersection group is the same, so through this scheme, as the number of antennas increases, the number of overlapping positions in the frequency domain will not increase, avoiding the interference with the continuous increase of the number of antennas.

[0091] In some examples, an intersection of a first set of frequency domain resource indexes and a second set of frequency domain resource indexes can be determined, wherein the intersection includes at least a first index; then a set of indexes of a plurality of frequency domain resources in a first group of frequency domain resources can be determined to include the first set of frequency domain resource indexes and a second index adjacent to the first index; and a set of indexes of a plurality of frequency domain resources in a second group of frequency domain resources can be determined to include the second set of frequency domain resource indexes and the second index. And for the reference signals to be transmitted on the frequency domain resources of the first index and the second index, a first group of orthogonal codes for a first antenna and a second group of orthogonal codes for a second antenna are respectively determined. For the convenience of description, this scheme can be referred to as a partially code-division multi-antenna scheme.

[0092] Specifically, for each index in the intersection, denoted as k0, the index adjacent to the index (e.g., k0-1 or k0+1) can also be used for the transmission of the reference signal. That is, the index (k0) in the intersection and its adjacent index (k0-1 or k0+1) are also used for the respective antennas to transmit the reference signal. Further, the respective antennas can utilize the orthogonal codes to transmit the reference signal on the frequency domain resources of the index (k0) in the intersection and its adjacent index (k0-1 or k0+1). For example, the orthogonal codes of the multiple antennas can form an orthogonal matrix.

[0093] For example, for a 2-antenna scenario, the determined orthogonal codes can be as shown in Table 3 or Table 4, where the adjacent index in Table 3 is k0-1 and the adjacent index in Table 4 is k0+1.

[0094] Table 3

[0095] Table 4

[0096] Based on the example, if the first set of frequency domain resource indices corresponding to antenna 1 is D1 as described above, it can be determined that, for example, the set of indices of the first group of frequency domain resources for antenna 1 includes D1 as described above and {102, 140, 161, 194, 197, 204, 368, 382, 472}, where each of {102, 140, 161, 194, 197, 204, 368, 382, 472} is an adjacent index of the corresponding index in the intersection A.

[0097] In some implementations of the present disclosure, the determined cyclic difference set is a cyclic difference set or a Singer cyclic difference set, etc. In some embodiments, the first set of frequency domain resource indices and the second set of frequency domain resource indices without intersection can be determined at operation 220.

[0098] In some examples, for a multi-antenna scenario, a plurality of sets of frequency domain resource indices corresponding to the plurality of antennas one-to-one can be determined, and there is no intersection between each two of the plurality of sets of frequency domain resource indices. For the convenience of description, this scheme can be referred to as a multi-antenna scheme based on completely non-intersecting sets.

[0099] For example, a plurality of non-intersecting sets can be determined based on a cyclic difference set as the plurality of sets of frequency domain resource indices for the multi-antenna. In an example, when p = 2f + 1 ≥ 7 and p ≡ 3 (mod 4), the parameter can be taken as C0, C1 are two non-intersecting sets. In an example, when p = 4f + 1 and f is an odd square element, the parameter can be taken as C0, C1, C2, and C3 are four disjoint sets. In one example, when p = 8f + 1 = 64u + 9 and f and u are both odd square elements, the parameters can be taken as... C0, ..., C7 are 8 disjoint sets.

[0100] For example, multiple disjoint sets can be determined based on Singer's cyclic difference set, serving as multiple frequency domain resource index sets for multiple antennas. As an example, we can take d = 2, then D and 2D + s are two disjoint difference sets, where s satisfies s ≡ log0 α b -2 (mod N), Satisfies: Tr(b) when q≡1 (mod 4) 2 )yes The square element; Tr(b) when q≡3 (mod 4) 2 )yes The non-square element.

[0101] For example, at operation 240, the index set of multiple frequency domain resources in the first group of frequency domain resources can be determined as the first frequency domain resource index set, and the index set of multiple frequency domain resources in the second group of frequency domain resources can be determined as the second frequency domain resource index set. Specifically, the multiple non-overlapping frequency domain resource index sets can be used for the transmission of reference signals on their respective antennas.

[0102] In some implementations of this disclosure, the determined cyclic difference set can be a circular difference set, a Singer cyclic difference set, or another type of cyclic difference set. For example, the cyclic difference set on which operation 220 is based can be any type of cyclic difference set. Exemplarily, the cyclic difference set can be selected based on the amount of frequency domain resources (e.g., half of that amount). For example, for multiple candidate difference sets of a certain type, a cyclic difference set can be selected from the multiple candidate difference sets such that the first parameter (i.e., v) of the selected cyclic difference set is closest to half of the amount of frequency domain resources (i.e., N / 2).

[0103] In some examples, the absolute value of the difference between the first parameter of the cyclic difference set and half the number of frequency domain resources is less than the absolute value of the difference between the first parameter of any candidate difference set other than the cyclic difference set and half the number of frequency domain resources in the plurality of candidate difference sets.

[0104] For example, assuming N = 585, the cyclic difference set (307, 18, 1) can be selected from the Singer difference set as shown in Table 1. For example, assuming N = 1170, the cyclic difference set (585, 73, 9) can be selected from the Singer difference set as shown in Table 1. It should be noted that the examples herein are merely illustrative and should not be construed as limiting the embodiments of the present disclosure, and other types of cyclic difference sets are also applicable.

[0105] In some embodiments, each value in a first set of the multiple sets of cyclic difference sets can be mapped to two frequency domain resource indices to obtain a first set of frequency domain resource indices. For example, a value i in the first set corresponds to indices 2i-1 and 2i in the first set of frequency domain resource indices, where i is a positive integer. In some embodiments, each value in a second set of the multiple sets of cyclic difference sets can be mapped to two frequency domain resource indices to obtain a second set of frequency domain resource indices. For example, a value j in the second set corresponds to indices 2j-1 and 2j in the second set of frequency domain resource indices, where j is a positive integer. For the convenience of description, this scheme can be referred to as a full code division based multi-antenna scheme.

[0106] Specifically, at operation 220, Na sets corresponding to Na antennas can be determined from the multiple sets of cyclic difference sets, and then for each of the Na sets, one value in the set can be mapped to two frequency domain resource indices to obtain a corresponding set of frequency domain resource indices. For example, a value i in the set is mapped to frequency domain resource indices 2i-1 and 2i. FIG. 3 shows a schematic diagram of a mapping 300 between values in a set of cyclic difference sets and frequency domain resource indices according to some example embodiments of the present disclosure. As shown in FIG. 3, value 1 in the set is mapped to frequency domain resource indices 1 and 2, value 7 is mapped to frequency domain resource indices 13 and 14, and so on.

[0107] For example, at operation 240, a set of indices of the multiple frequency domain resources in the first group of frequency domain resources can be determined as the first set of frequency domain resource indices, and a set of indices of the multiple frequency domain resources in the second group of frequency domain resources can be determined as the second set of frequency domain resource indices. Specifically, the multiple sets of mapped frequency domain resource indices can be used for transmission of reference signals on corresponding antennas, respectively.

[0108] Now returning to FIG. 2, at operation 260, the first device 201 can transmit the plurality of reference signals through the plurality of antennas respectively. Specifically, the plurality of reference signals can be transmitted through the first antenna on the first set of frequency domain resources, and the plurality of reference signals can be transmitted through the second antenna on the second set of frequency domain resources. It can be understood that in the Singer cyclic difference set shift group based multi-antenna scheme and the complete non-intersecting set based multi-antenna scheme as described above, the different sets of frequency domain resources for different antennas are independent, i.e., disjoint. In the partial code division based multi-antenna scheme as described above, the different sets of frequency domain resources for different antennas have intersections, and the orthogonal codes are applied at the index and the adjacent index in the intersection. In the full code division based multi-antenna scheme as described above, the OCC code division can be utilized, and the frequency domain resources are saved.

[0109] With continued reference to FIG. 2, at operation 260, the second device 202 receives the plurality of reference signals from the first device 201 in the process 200. In some implementations, the second device 202 can optionally determine the cyclic difference set at operation 215. In some implementations, the second device 202 can similarly determine the first set of frequency domain resource indices and the second set of frequency domain resource indices at operation 225, and determine the first set of frequency domain resources and the second set of frequency domain resources at operation 245. Specifically, the second device 202 can determine the plurality of sets of frequency domain resources corresponding to the plurality of antennas respectively. The determination manner is similar to that provided by the first device 201 as described above, and thus will not be repeated here. For example, the second device 202 can detect and receive the reference signals on the determined plurality of sets of frequency domain resources.

[0110] Additionally or alternatively, at operation 280, the second device 202 can perform channel estimation based on the received reference signals. Specifically, the channel estimation can be performed based on the received values of the reference signals through the respective antennas.

[0111] In the Singer cyclic difference set shift group based multi-antenna scheme and the complete non-intersecting set based multi-antenna scheme as described above, the different sets of frequency domain resources for different antennas are independent, i.e., disjoint. The second device 202 can determine the received values of the reference signals at the respective frequency domain resources, and perform channel estimation based on the received values.

[0112] In the partial code division based multi-antenna scheme as described above, the different sets of frequency domain resources for different antennas have intersections, and the orthogonal codes are applied at the index and the adjacent index in the intersection. The second device 202 can determine the received values of the reference signals on the index and the adjacent index in the intersection, and further determine the plurality of received values corresponding to the plurality of antennas respectively based on the received values, and then can perform channel estimation based on the plurality of received values corresponding to the plurality of antennas respectively.

[0113] For example, taking the index in the intersection and the adjacent index of the index as k0and k0-1, respectively, and assuming for a 2-antenna scenario, the orthogonal codes are as shown in Table 3 above. Let the frequency domain channel response on the frequency domain resource at index k0-1and the frequency domain resource at index k0be the same, i.e., H k0 = H k0-1 If the received value on the frequency domain resource at index k0by the second device 202 is denoted as Y k0 , the received value on the frequency domain resource at index k0-1is denoted as Y k0-1 , then based on the orthogonal codes, the received values on the respective antennas can be determined as shown in the following equations (7)-(8). Y 1,k0 = (Y k0 + Y k0-1 ) / 2 (7) Y 2,k0 = (Y k0 - Y k0-1 ) / 2 (8)

[0114] In equations (7) and (8), Y 1,k0 and Y 2,k0 denote the received values on the frequency domain resource k0by antenna 1 and antenna 2, respectively.

[0115] Exemplarily, the corresponding processing is performed for each overlapping frequency domain resource (i.e., each index in the intersection), so that the second device 202 can obtain the received values for each antenna. Optionally, the second device 202 can use a channel estimation algorithm (e.g., the existing OMP algorithm, etc.) to obtain the result of channel estimation based on the received values.

[0116] In the full codebook-based multi-antenna scheme as described above, based on the mapping as shown in FIG. 3, the frequency domain resources for transmitting the reference signal can include a plurality of pairs, each pair including two adjacent frequency domain resources. At operation 280, the second device 202 can perform channel estimation based on the received values at the respective frequency domain resources. Exemplarily, the equivalent channel received values can be determined based on the reference signal received values by the respective antennas. Exemplarily, the channel estimation can be performed using the OMP algorithm based on the equivalent channel received values.

[0117] For example, taking antenna 1 as an example, the received values of the reference signal by the second device 202 on the frequency domain resource 2i-1and the frequency domain resource 2iare Y 1,2i-1 and Y 1,2i , respectively, and the following equation (9) can be obtained.

[0118] X P in equation (9) denotes the received reference signal vector, H jdenotes a frequency domain channel coefficient, W denotes a frequency domain noise. The second device 202 can determine a received signal vector of the equivalent channel based on the received value, denoted as Y p_occ as obtained by equation (10) as follows. Y p_occ = diag(X p_occ )*F DFT *h occ = Φh + W (10)

[0119] In equation (10), X p_occ denotes a vector of reference signals in the equivalent channel, F DFT denotes a Fourier matrix of size N / 2, h occ denotes an equivalent time domain channel vector of size N / 2 x 1. Further, by performing OMP estimation on equation (10), an estimated value of h occ can be obtained, converted back to the frequency domain, and then mapped to the frequency domain channel.

[0120] In this way, according to the embodiments described in connection with FIG. 2, for a multi-antenna system, frequency domain resources of reference signals transmitted through respective antennas are determined such that interference between different antennas is small. In this way, a suitable pilot pattern can be determined, and better channel estimation performance can be obtained. The frequency domain resource determination scheme of reference signals based on cyclic difference sets belongs to a compressed sensing channel estimation algorithm, which takes advantage of the sparsity of channels to effectively recover channel responses with lower pilot overhead, thereby achieving better channel performance.

[0121] Various schemes of embodiments of the present disclosure will be compared with some existing schemes below. Exemplarily, an existing scheme can include “randomly selected difference sets”, which refers to randomly selecting multiple sets for multiple antennas (such as 2 or 4), i.e., the multiple sets do not satisfy the restriction that the intersection of each pair of sets is the same as described above for the intersection group. Exemplarily, an existing scheme can include “5G NR (CDM+FDM)”, which assumes that adjacent subcarrier frequency domain channels are the same, and uses orthogonal codes 1 and -1 to obtain an equivalent channel at a certain frequency domain resource, and then interpolates the obtained equivalent channel to obtain equivalent channels at other frequency domain resources. Exemplarily, an existing scheme can include “single antenna difference sets”, which is for a single antenna scenario, i.e., a scenario in which there is no interference from other antennas to the single antenna.

[0122] FIG. 4 shows a diagram of comparison results 400 between a Singer cyclic difference set shift group multi-antenna scheme and multiple existing schemes according to an embodiment of the present disclosure. The simulation environment on which the comparison results 400 in FIG. 4 are based is shown in Table 5 below. The “difference set scheme one” in FIG. 4 represents the Singer cyclic difference set shift group multi-antenna scheme of an embodiment of the present disclosure, and assumes that the index set determined for 4 antennas is D1, D2, D3, and D4 determined from equation (6) as shown above. 10 11 44 .

[0123] Table 5

[0124] As can be seen from the comparison results in FIG. 4, the curve 410 of “randomly selected difference set” shows that the interference of reference signals between 4 antennas is large, and the estimation performance is the worst among the 4 schemes. The curve 420 of “5G NR (CDM+FDM)” shows that its performance is better than that of “randomly selected difference set”, but is worse than that of the scheme in the present disclosure. The curve 440 of “single antenna difference set” can be understood as a lower bound of performance because there is no interference. The curve 430 of “difference set scheme one” in the present disclosure is close to the curve 440, and it can be seen that the Singer cyclic difference set shift group multi-antenna scheme is very close to the estimation performance of a single antenna, and it can be seen that the Singer cyclic difference set shift group multi-antenna scheme reduces the interference between antennas, which reflects the effectiveness of the reference signal design of the Singer cyclic difference set shift group multi-antenna scheme.

[0125] FIG. 5 shows a diagram of comparison results 500 between a partial code division multi-antenna scheme and multiple existing schemes according to an embodiment of the present disclosure. The simulation environment on which the comparison results 500 in FIG. 5 are based is shown in Table 6 below. The “multi-antenna scheme two” in FIG. 5 represents the partial code division multi-antenna scheme of an embodiment of the present disclosure.

[0126] Table 6

[0127] ​​From the comparison results of FIG. 5, it can be seen that the curve 510 of "randomly selected difference set" shows that the interference of the reference signals between the two antennas is large, and the estimation performance is the worst among the four schemes. The curve 520 of "5G NR (CDM+FDM)" shows that its performance is better than that of "randomly selected difference set", but is worse than the scheme in the present disclosure. The curve 540 of "single antenna difference set" can be understood as a performance lower bound because there is no interference. The curve 530 of "multi-antenna scheme two" in the present disclosure is close to the curve 540, and it can be seen that the multi-antenna scheme with partial code division is close to the estimation performance of the single antenna, has small attenuation compared with the single antenna, and does not lose channel information by zeroing. The channel estimation performance is related to the richness of the channel in the frequency domain. The slower the frequency domain channel changes, the better the estimation effect of the scheme.

[0128] FIG. 6 shows a schematic diagram of results 600 of a multi-antenna scheme based on a completely disjoint difference set according to an embodiment of the present disclosure. The simulation environment on which the results 600 in FIG. 6 are based is shown in Table 7 below.

[0129] Table 7

[0130] It is assumed that the determined cyclic difference set is D(v=301, k=18, λ=1), and the completely disjoint set for four antennas is as follows: D A ={1, 13, 17, 41, 73, 83, 106, 177, 183, 191, 192, 194, 221, 228, 241, 246, 267, 289}, D B ={3, 11, 39, 49, 51, 70, 109, 123, 124, 187, 219, 224, 242, 249, 253, 266, 269, 275}, D C ={7, 42, 78, 98, 100, 105, 108, 119, 131, 137, 165, 180, 181, 205, 250, 259, 297, 301}, D D ={31, 56, 89, 104, 139, 140, 144, 171, 214, 220, 231, 233, 240, 243, 261, 277, 285, 299}, (11)

[0131] From the results 600 of FIG. 6, it can be seen that because the difference sets between different antennas are based on a completely disjoint difference set in the frequency domain, there is no aliasing between different antennas in the frequency domain, and the four difference sets are orthogonal to each other in the frequency domain, so the performance of each antenna is the same as that of a single antenna.

[0132] FIG. 7 shows a schematic diagram of a comparison result 700 between the full-codebook-based multi-antenna scheme and the existing scheme according to an embodiment of the present disclosure. The simulation environment on which the comparison result 700 in FIG. 7 is based is shown in Table 8 below. “Full-codebook” in FIG. 7 represents the full-codebook-based multi-antenna scheme of an embodiment of the present disclosure.

[0133] Table 8

[0134] Suppose the determined cyclic difference set is Singer cyclic difference set D0(v = 585, k = 73, λ = 9), and the set for 2 antennas is D1and D2in formula (6) as discussed above. 10 .

[0135] As can be seen from the comparison result 700 of the curve 710 and the curve 720 in FIG. 7, the performance of the full-codebook-based multi-antenna scheme of an embodiment of the present disclosure is superior to that of the 5G NR-based codebook interpolation scheme under the same signal overhead, that is, the performance can be improved by using the full-codebook-based multi-antenna scheme of the present disclosure.

[0136] In this way, an embodiment of the present disclosure provides frequency domain resources for reference signals of multiple antennas. Exemplary multiple antenna schemes can include a Singer cyclic difference set shift group, a partial codebook-based multi-antenna scheme, a full-codebook-based multi-antenna scheme, and a full-codebook-based multi-antenna scheme. In some examples, the corresponding scheme can be selected based on different communication scenarios and channel conditions to meet the application requirements of OFDM compressed sensing channel estimation in a multi-antenna scenario. Therefore, the present disclosure can extend the reference signal pattern determination method to a multi-antenna scenario, and better fit the actual communication scenario and communication requirements.

[0137] FIG. 8 shows a schematic flowchart of a communication method 800 according to an embodiment of the present disclosure. The method 800 shown in FIG. 8 can be performed by the first device 201 or the second device 202 as shown in FIG. 2, or can be performed by an apparatus (such as a processor or a control circuit, etc.) inside the first device 201 or the second device 202. It should be understood that the method 800 can include additional actions not shown and / or some of the shown actions can be omitted, and the scope of the present disclosure is not limited thereto.

[0138] At 810, based on the cyclic difference set, a first set of frequency domain resource indexes and a second set of frequency domain resource indexes are determined. In some examples, the operation at 810 can refer to the discussion in connection with operation 220 in FIG. 2, which will not be repeated here for brevity.

[0139] At 820, based on the first set of frequency domain resource indexes and the second set of frequency domain resource indexes, a first set of frequency domain resources for transmitting the plurality of reference signals through the first antenna and a second set of frequency domain resources for transmitting the plurality of reference signals through the second antenna are determined. In some examples, the operations at 820 can be discussed with reference to the discussion of operation 240 in FIG. 2, which will not be repeated here for brevity.

[0140] The method 800 can include various other operations that can be performed by the first device 201 or the second device 202, as discussed above with reference to FIG. 2. In some examples, the first device 201 can transmit the reference signals through the first antenna and the second antenna. In some examples, the second device 202 can receive the reference signals through the first antenna and the second antenna. In some examples, the second device 202 can perform channel estimation based on the received reference signals. Details can be referred to the foregoing description in conjunction with the part of FIG. 2, which will not be repeated here for brevity.

[0141] It should be understood that in the embodiments of the present disclosure, “first”, “second”, “third” and the like are only used to represent that the plurality of objects can be different, but at the same time, it does not exclude that the two objects are the same. “First”, “second”, “third” and the like should not be interpreted as any limitation on the embodiments of the present disclosure.

[0142] It should also be understood that the manners, cases, categories and divisions of embodiments in the embodiments of the present disclosure are only for the convenience of description, and should not constitute special limitations. The features in various manners, categories, cases and embodiments can be combined with each other as long as they are logically consistent.

[0143] It should also be understood that the above description is only to help those skilled in the art better understand the embodiments of the present disclosure, and is not intended to limit the scope of the embodiments of the present disclosure. Those skilled in the art can make various modifications or changes or combinations, etc. according to the above description. The schemes after such modifications, changes or combinations are also within the scope of the embodiments of the present disclosure.

[0144] It should also be understood that the above description focuses on the differences between various embodiments, and the same or similar parts can be referred to or learned from each other, and will not be repeated here for brevity.

[0145] FIG. 9 shows a schematic block diagram of an apparatus 900 for communication, according to some embodiments of the present disclosure. The apparatus 900 includes an index set determination module 910 and a resource determination module 920. The index set determination module 910 is configured to determine a first set of frequency domain resource indexes and a second set of frequency domain resource indexes based on a cyclic difference set. The resource determination module 920 is configured to determine a first set of frequency domain resources for transmitting a plurality of reference signals through a first antenna and a second set of frequency domain resources for transmitting the plurality of reference signals through a second antenna based on the first set of frequency domain resource indexes and the second set of frequency domain resource indexes.

[0146] In some embodiments of the present disclosure, the apparatus 900 can further include a difference set determination module configured to determine the cyclic difference set from a plurality of candidate difference sets based on a number of frequency domain resources and a number of reference signals. In some examples, the difference set determination module can be configured to determine a first candidate difference set from the plurality of candidate difference sets as the cyclic difference set if an absolute value of a difference between a first parameter of the first candidate difference set and the number of frequency domain resources is smaller than an absolute value of a difference between a first parameter of any candidate difference set from the plurality of candidate difference sets other than the first candidate difference set and the number of frequency domain resources. In some examples, the difference set determination module can be configured to compare a second parameter of a second candidate difference set from the plurality of candidate difference sets with a second parameter of a third candidate difference set from the plurality of candidate difference sets if the first parameter of the second candidate difference set is equal to the first parameter of the third candidate difference set and an absolute value of a difference between the first parameter of the second candidate difference set and the number of frequency domain resources is smaller than an absolute value of a difference between the first parameter of any candidate difference set from the plurality of candidate difference sets other than the second candidate difference set and the third candidate difference set and the number of frequency domain resources, and determine the second candidate difference set as the cyclic difference set if an absolute value of a difference between the second parameter of the second candidate difference set and the number of reference signals is smaller than an absolute value of a difference between the second parameter of the third candidate difference set and the number of reference signals. Optionally, an intersection of any two sets from a plurality of sets of the cyclic difference set is identical, and wherein the plurality of sets includes the first set of frequency domain resource indexes and the second set of frequency domain resource indexes.

[0147] In some embodiments of the present disclosure, the resource determination module 920 can be configured to determine an intersection of the first set of frequency domain resource indexes and the second set of frequency domain resource indexes, determine that the set of indexes of the plurality of frequency domain resources in the first set of frequency domain resources includes a portion of the first set of frequency domain resource indexes other than the intersection and a portion of the intersection, and determine that the set of indexes of the plurality of frequency domain resources in the second set of frequency domain resources includes a portion of the second set of frequency domain resource indexes other than the intersection and a remaining portion of the intersection. Illustratively, an absolute value of a difference between a number of indexes in the portion of the intersection and a number of indexes in the remaining portion of the intersection is smaller than a preset threshold.

[0148] In some embodiments of the disclosure, the resource determining module 920 can be configured to: determine an intersection of the first set of frequency domain resource indices and the second set of frequency domain resource indices, wherein the intersection comprises at least the first index; determine that the set of indices of the plurality of frequency domain resources in the first group of frequency domain resources comprises the first set of frequency domain resource indices and a second index adjacent to the first index; and determine that the set of indices of the plurality of frequency domain resources in the second group of frequency domain resources comprises the second set of frequency domain resource indices and the second index. Illustratively, the resource determining module 920 is further configured to: determine, for the reference signals to be transmitted on the frequency domain resources of the first index and the second index, the first group of orthogonal codes for the first antenna and the second group of orthogonal codes for the second antenna, respectively.

[0149] In some embodiments of the disclosure, the first set of frequency domain resource indices and the second set of frequency domain resource indices have no intersection, and the set of indices of the plurality of frequency domain resources in the first group of frequency domain resources is the first set of frequency domain resource indices, and the set of indices of the plurality of frequency domain resources in the second group of frequency domain resources is the second set of frequency domain resource indices.

[0150] In some embodiments of the disclosure, the apparatus 900 can further comprise a difference set determining module configured to determine, based on the number of frequency domain resources and the number of reference signals, a cyclic difference set from a plurality of candidate difference sets, wherein an absolute value of a difference between a first parameter of the cyclic difference set and half of the number of frequency domain resources is smaller than an absolute value of a difference between the first parameter of any candidate difference set other than the cyclic difference set from the plurality of candidate difference sets and half of the number of frequency domain resources.

[0151] Illustratively, the resource determining module 920 can be configured to: map each value in a first set of the plurality of sets of the cyclic difference set to two frequency domain resource indices to obtain the first set of frequency domain resource indices; and map each value in a second set of the plurality of sets of the cyclic difference set to two frequency domain resource indices to obtain the second set of frequency domain resource indices. Illustratively, a value i in the first set corresponds to indices 2i-1 and 2i in the first set of frequency domain resource indices, where i is a positive integer. Illustratively, a value j in the second set corresponds to indices 2j-1 and 2j in the second set of frequency domain resource indices, where j is a positive integer.

[0152] Illustratively, the set of indices of the plurality of frequency domain resources in the first group of frequency domain resources is the first set of frequency domain resource indices, and the set of indices of the plurality of frequency domain resources in the second group of frequency domain resources is the second set of frequency domain resource indices.

[0153] In some embodiments of the disclosure, the apparatus 900 can further comprise a transceiving module 930 configured to: transmit, through the first antenna, the plurality of reference signals on the first group of frequency domain resources; and transmit, through the second antenna, the plurality of reference signals on the second group of frequency domain resources.

[0154] In some embodiments of the present disclosure, the apparatus 900 can further include a receiving module 930 configured to receive the plurality of reference signals on the first set of frequency domain resources through the first antenna and receive the plurality of reference signals on the second set of frequency domain resources through the second antenna. Illustratively, the apparatus 900 can further include a channel estimation module configured to perform channel estimation based on the reference signal received values through the first antenna and the reference signal received values through the second antenna. Optionally, the channel estimation module can be configured to determine equivalent channel received values based on the reference signal received values through the first antenna and the reference signal received values through the second antenna, and perform channel estimation using an orthogonal matching pursuit algorithm based on the equivalent channel received values.

[0155] The division of modules or units in the embodiments of the present disclosure is illustrative, and is merely a logical function division. In actual implementation, another division manner can be used, and each functional unit in the disclosed embodiments can be integrated into one unit, or can be physically present separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in the form of hardware, or in the form of a software functional unit.

[0156] Illustratively, the apparatus 900 in FIG. 9 can be implemented as a communication device, or can be implemented as a chip or chip system in a device. The apparatus 900 in FIG. 9 can be used to implement the above-described various processes in conjunction with FIG. 2, and for brevity, will not be described here.

[0157] FIG. 10 shows a schematic block diagram of an example device 1000 that can be used to implement embodiments of the present disclosure. The device 1000 can be implemented as or included in the first device 201 or the second device 202 of FIG. 2, or the device 1000 can be implemented as or included in the network device 110 or the terminal device 120 of FIG. 1.

[0158] As shown in FIG. 10, the device 1000 includes one or more processors 1010, one or more memories 1020 coupled to the processors 1010, and a communication module 1040 coupled to the processors 1010.

[0159] The communication module 1040 can be used for bidirectional communication. The communication module 1040 can have at least one communication interface for communication. The communication interface can include any interface necessary for communication with other devices.

[0160] The processor 1010 can be of any type suitable to the local technical network, and can include at least one of the following: a general purpose computer, a special purpose computer, a microcontroller, a Digital Signal Processor (DSP), or one or more of a plurality of cores in a controller-based multi-core processor architecture. The device 1000 can have multiple processors, e.g., special integrated circuit chips, that are time-slaved to a clock that is synchronized with the main processor.

[0161] The memory 1020 can include one or more non-transitory memories and one or more transitory memories. Examples of non-transitory memories include, but are not limited to, at least one of the following: a Read-Only Memory (ROM) 1024, an Erasable Programmable Read Only Memory (EPROM), flash memory, a hard disk, a Compact Disc (CD), a Digital Versatile Disc (DVD), or other magnetic storage and / or optical storage. Examples of transitory memories include, but are not limited to, at least one of the following: a Random Access Memory (RAM) 1022, or other volatile memory that does not persist for the duration of a power cycle.

[0162] The computer program 1030 includes computer executable instructions executed by the associated processor 1010. The program 1030 can be stored in the ROM 1024. The processor 1010 can perform any suitable action and processing by loading the program 1030 into the RAM 1022.

[0163] Embodiments of the present disclosure can be implemented with the aid of the program 1030, such that the device 1000 can perform any of the processes as discussed with reference to Figure 2. Embodiments of the present disclosure can also be implemented by hardware or by a combination of software and hardware.

[0164] The program 1030 can be tangibly embodied in a computer readable medium, which can include other storage devices that are in the device 1000, such as in the memory 1020, or that are accessible by the device 1000. The program 1030 can be loaded from the computer readable medium into the RAM 1022 for execution. The computer readable medium can include any type of tangible non-transitory memory, such as a ROM, an EPROM, a flash memory, a hard disk, a CD, a DVD, and the like.

[0165] In some embodiments, the communication module 1040 in the device 1000 can be implemented as a transmitter and a receiver (or transceiver), which can be configured to send / receive, for example, a plurality of TCIs, at least one message, capability information, and the like. In addition, the device 1000 can further include one or more of a scheduler, a controller, a radio frequency / antenna, which will not be elaborated in detail in the present disclosure.

[0166] By way of example, the device 1000 in FIG. 10 can be implemented as an electronic device, or can be implemented as a chip or a chip system in an electronic device, and the embodiments of the present disclosure are not limited thereto.

[0167] Embodiments of the present disclosure further provide a chip, which can include an input interface, an output interface, and a processing circuit. In embodiments of the present disclosure, the interaction of signaling or data can be completed by the input interface and the output interface, and the generation and processing of signaling or data information can be completed by the processing circuit.

[0168] Embodiments of the present disclosure further provide a chip system including a processor for supporting a communication device to implement the functions involved in any of the above embodiments. In a possible design, the chip system can further include a memory for storing necessary program instructions and data, which, when the processor runs the program instructions, causes the device in which the chip system is installed to implement the methods involved in any of the above embodiments. By way of example, the chip system can be composed of one or more chips, or can include chips and other discrete devices.

[0169] Embodiments of the present disclosure further provide a processor for coupling with a memory, the memory storing instructions, which, when executed by the processor, cause the processor to perform the methods and functions involved in any of the above embodiments.

[0170] Embodiments of the present disclosure further provide a computer program product containing instructions, which, when executed on a computer, cause the computer to perform the methods and functions involved in any of the above embodiments.

[0171] Embodiments of the present disclosure further provide a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, cause the processor to perform the methods and functions involved in any of the above embodiments.

[0172] In general, the various embodiments of the present disclosure can be implemented in hardware or 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, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein can be implemented in, as non-limiting examples, hardware, software, firmware, special-purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0173] The present disclosure also provides at least one computer program product which is tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer executable instructions, for example, instructions executed by a device on a target real or virtual processor to perform processes / methods as described above with reference to the accompanying drawings. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of program modules can be combined or split between program modules as desired. Machine executable instructions for program modules can be executed within a local or distributed device. In a distributed device, program modules can be located in local and remote memory storage devices.

[0174] Computer program code for carrying out operations of the present disclosure can be written in one or more programming languages. These computer program code can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the program code, which executes via the processor of the computer or other programmable data processing apparatus, transforms the computer or other programmable data processing apparatus into a particular machine implementing the functions / acts specified in the flowcharts and / or block diagrams. Program code can be completely executed on a computer, partially executed on a computer, as a standalone software package, partially on a computer and partially on a remote computer, or completely on a remote computer or server.

[0175] In the context of the present disclosure, computer program code or related data can be carried by any suitable carrier, to enable a device, apparatus or processor to perform the various processes and operations described above. Examples of carriers include signals, computer readable media, and the like. Examples of signals can include electrical, optical, radio, sound or other forms of propagated signals, such as carrier waves, infrared signals, and the like.

[0176] A computer readable medium can be any tangible medium that includes or stores the programs for use by or in connection with the instruction execution system, apparatus, or device. The computer readable medium can be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium can include but is not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium 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), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanism that stores information of bit magnetic, optical, or other propagation mediums such as a carrier wave traveling through the air or a bus that carries electrical signals in a wire, cable, or other transmission mediums. The computer readable storage medium is specifically not a transitory signal per se.

[0177] Moreover, while operations of the methods of the present disclosure are described in a particular order in the drawings, this is not required or implied in any particular order for performing the operations, or that all operations be performed to achieve desirable results. Rather, the steps depicted in the flowcharts can be changed in order of execution. Additionally or alternatively, certain steps can be omitted, combined into a single step, and / or broken into multiple steps. It is also noted that features and functionalities of two or more devices according to the present disclosure can be embodied in one device. Conversely, features and functionalities of one device described above can be further divided into multiple devices.

[0178] The implementations of the disclosure have been described above with the intent to be illustrative rather than limiting. Although the implementations of the disclosure have been described with regard to particular implementations, it will be understood that changes in form and detail can be made to implementations without departing from the spirit, nature, or scope of the implementations. The choice of words used in the specification is intended to be instructive and not limiting. The use of the terms "including" and "comprising" are open-ended and are intended to mean that other items can also be present in addition to the items recited.

Claims

1. A method for communication, comprising: Based on the cyclic difference set, determine the first frequency domain resource index set and the second frequency domain resource index set; as well as Based on the first frequency domain resource index set and the second frequency domain resource index set, a first set of frequency domain resources for transmitting multiple reference signals through the first antenna and a second set of frequency domain resources for transmitting multiple reference signals through the second antenna are determined.

2. The method according to claim 1, further comprising: The cyclic difference set is determined from multiple candidate difference sets based on the number of frequency domain resources and the number of reference signals.

3. The method of claim 2, wherein determining the cyclic difference set from a plurality of candidate difference sets comprises: If the absolute value of the difference between the first parameter of the first candidate difference set in the plurality of candidate difference sets and the number of frequency domain resources is less than the absolute value of the difference between the first parameter of any candidate difference set other than the first candidate difference set in the plurality of candidate difference sets and the number of frequency domain resources, then the first candidate difference set is determined to be the cyclic difference set.

4. The method of claim 2, wherein determining the cyclic difference set from a plurality of candidate difference sets comprises: If the first parameter of the second candidate difference set in the plurality of candidate difference sets is equal to the first parameter of the third candidate difference set in the plurality of candidate difference sets, and the absolute value of the difference between the first parameter of the second candidate difference set and the number of frequency domain resources is less than the absolute value of the difference between the first parameter of any candidate difference set in the plurality of candidate difference sets other than the second candidate difference set and the third candidate difference set and the number of frequency domain resources, then the second parameter of the second candidate difference set is compared with the second parameter of the third candidate difference set. as well as If the absolute value of the difference between the second parameter of the second candidate difference set and the number of reference signals is less than the absolute value of the difference between the second parameter of the third candidate difference set and the number of reference signals, then the second candidate difference set is determined to be the cyclic difference set.

5. The method according to any one of claims 1 to 4, wherein the intersection of any two sets in the plurality of sets of the cyclic difference set is the same, and wherein the plurality of sets includes the first frequency domain resource index set and the second frequency domain resource index set.

6. The method of claim 5, wherein determining the first group of frequency domain resources and the second group of frequency domain resources comprises: Determine the intersection of the first frequency domain resource index set and the second frequency domain resource index set; Determining the index set of multiple frequency domain resources in the first group of frequency domain resources includes: the portion of the first frequency domain resource index set excluding the intersection and a portion of the intersection; and Determining the index set of multiple frequency domain resources in the second group of frequency domain resources includes: the portion of the second frequency domain resource index set excluding the intersection and the remaining portion of the intersection.

7. The method according to claim 6, wherein the absolute value of the difference between the number of indices in the portion of the intersection and the number of indices in the remaining portion of the intersection is less than a preset threshold.

8. The method of claim 5, wherein determining the first set of frequency domain resources and the second set of frequency domain resources comprises: Determine the intersection of the first frequency domain resource index set and the second frequency domain resource index set, wherein the intersection includes at least the first index; Determining the index set of multiple frequency domain resources in the first group of frequency domain resources includes: the first frequency domain resource index set and a second index adjacent to the first index; and The set of indexes for multiple frequency domain resources in the second group of frequency domain resources includes: the second set of frequency domain resource indexes and the second index.

9. The method according to claim 8, further comprising: For the reference signals to be transmitted on the frequency domain resources of the first index and the second index, a first set of orthogonal codes for the first antenna and a second set of orthogonal codes for the second antenna are determined respectively.

10. The method according to claim 1, wherein the first frequency domain resource index set and the second frequency domain resource index set have no intersection, and wherein the index set of multiple frequency domain resources in the first group of frequency domain resources is the first frequency domain resource index set, and the index set of multiple frequency domain resources in the second group of frequency domain resources is the second frequency domain resource index set.

11. The method according to claim 1, further comprising: Based on the number of frequency domain resources and the number of reference signals, the cyclic difference set is determined from multiple candidate difference sets, wherein the absolute value of the difference between the first parameter of the cyclic difference set and half of the number of frequency domain resources is less than the absolute value of the difference between the first parameter of any candidate difference set other than the cyclic difference set and half of the number of frequency domain resources in the multiple candidate difference sets.

12. The method of claim 11, wherein determining the first frequency domain resource index set and the second frequency domain resource index set comprises: Each value in the first set of the multiple sets of the cyclic difference set is mapped to two frequency domain resource indices to obtain the first frequency domain resource index set; as well as Each value in the second set of the plurality of sets of the cyclic difference is mapped to two frequency domain resource indices to obtain the second frequency domain resource index set.

13. The method according to claim 12, wherein the value i in the first set corresponds to indices 2i-1 and 2i in the first frequency domain resource index set, where i is a positive integer. The value j in the second set corresponds to the indices 2j-1 and 2j in the second frequency domain resource index set, where j is a positive integer.

14. The method according to claim 12 or 13, wherein the index set of multiple frequency domain resources in the first group of frequency domain resources is the first frequency domain resource index set, and the index set of multiple frequency domain resources in the second group of frequency domain resources is the second frequency domain resource index set.

15. The method according to any one of claims 1 to 14, further comprising: The plurality of reference signals are transmitted over the first group of frequency domain resources via the first antenna; as well as The plurality of reference signals are transmitted over the second set of frequency domain resources via the second antenna.

16. The method according to any one of claims 1 to 14, further comprising: The plurality of reference signals are received over the first group of frequency domain resources via the first antenna; The plurality of reference signals are received over the second set of frequency domain resources via the second antenna; as well as Channel estimation is performed based on the reference signal received through the first antenna and the reference signal received through the second antenna.

17. The method according to any one of claims 11 to 14, further comprising: The plurality of reference signals are received over the first group of frequency domain resources via the first antenna; The plurality of reference signals are received over the second set of frequency domain resources via the second antenna; The equivalent channel received value is determined based on the reference signal received value through the first antenna and the reference signal received value through the second antenna. as well as Based on the equivalent channel received value, channel estimation is performed using an orthogonal matching pursuit algorithm.

18. A communication device for performing the method according to any one of claims 1-17.

19. The communication device according to claim 18, comprising: The index set determination module is configured to determine the first frequency domain resource index set and the second frequency domain resource index set based on cyclic difference sets. as well as The resource determination module is configured to determine, based on the first frequency domain resource index set and the second frequency domain resource index set, a first set of frequency domain resources for transmitting multiple reference signals through the first antenna and a second set of frequency domain resources for transmitting multiple reference signals through the second antenna.

20. The communication device of claim 18, comprising one or more processors configured to: Based on the cyclic difference set, determine the first frequency domain resource index set and the second frequency domain resource index set; and Based on the first frequency domain resource index set and the second frequency domain resource index set, a first set of frequency domain resources for transmitting multiple reference signals through the first antenna and a second set of frequency domain resources for transmitting multiple reference signals through the second antenna are determined.

21. A communication device, comprising: One or more processors; as well as A memory storing instructions that, when executed by the one or more processors, cause the communication device to perform the method according to any one of claims 1-17.

22. A computer-readable storage medium having instructions stored thereon, which, when executed by a device, cause the device to perform the method according to any one of claims 1-17.

23. A computer program product storing instructions that, when executed, cause a device to perform the method according to any one of claims 1-17.

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