Wireless communication method and related apparatus

Abstract

Provided are a wireless communication method and related apparatus. The method includes: transmitting a first reference signal using first resource elements (REs) associated with a first antenna port is transmitted, where positions of the first REs are indicated by a first position sequence; transmitting second reference signal using second REs associated with a second antenna port, where positions of the second REs are indicated by a second position sequence; here the first position sequence and the second position sequence are obtained based on at least one target position set, each of the at least one target position set is a difference set, an almost difference set or a near difference set, and where the first antenna port is different from the second antenna port and the first position sequence is different from the second position sequence. Positions of REs occupied by a reference signal may be indicated by a position sequence. Position sequences are different for different antenna ports, and thus complete overlapping between REs occupied by reference signals from different antenna ports can be avoided, which may enable reasonable resource allocation.

Description

WIRELESS COMMUNICATION METHOD AND RELATED APPARATUSTECHNICAL FIELD

[0001] The present application relates to the field of communication technologies, and in particular, to a wireless communication method and related apparatus.BACKGROUND

[0002] The current trend in multiple-input multiple-output (MIMO) communications is the increase in the number of antennas, subcarriers and total bandwidth of a communication system. If traditional methods are applied for channel estimation in such scenario, the overhead will be too large to meet requirements on achievable rate. Thus, new channel estimation techniques are required.

[0003] This background information is provided to reveal information believed by the applicant to be of possible relevance to the present application. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present application.SUMMARY|0004] In a first aspect, a wireless communication method is provided by the present disclosure, and the method comprises: transmitting a first reference signal using first resource elements (REs) associated with a first antenna port, where positions of the first REs are indicated by a first position sequence; transmitting a second reference signal using second REs associated with a second antenna port, where positions of the second REs are indicated by a second position sequence; where the first position sequence and the second position sequence are obtained based on at least one target position set, each of the at least one target position set is a difference set, an almost difference set or a near difference set, and where the first antenna port is different from the second antenna port and the first position sequence is different from the second position sequence.

[0005] REs occupied by a reference signal may be associated with an antenna port and positions of the REs occupied may be indicated by a position sequence. Position sequences are different for different antenna ports, and thus complete overlapping between REs occupied by reference signals from different antenna ports can be avoided, which may enable reasonable resource allocation.

[0006] In addition, at least one of the difference set, the almost difference set and the near difference set is used to obtain the position sequences for different antenna ports, and thus, the amount of overlap between REs occupied by reference signals from different antenna ports can be precisely controlled, so that the cross-interference level between the antenna ports can be controlled and the transmission quality of the reference signals can be ensured, thereby improving channel estimation performance.

[0007] In a possible implementation of the first aspect, the first position sequence and the second position sequence have at least one common element.

[0008] Since the first position sequence and the second position sequence are obtained based on at least onetarget position set, and each target position set is a difference set, an almost difference set or a near difference set, the first position sequence and the second position sequence may have one or more common elements, depending at least on one or more parameters of the target position set. Further, since positions of REs occupied by reference signals from the first and second antenna ports are indicated by the first and second positions sequence, respectively, there may be one or more common REs (i.e., the overlapping REs) between REs occupied by reference signals from the first and second antenna ports, and the number of the common REs may depend at least on one or more parameters of the target position set. Therefore, the number of the common REs can be easily and precisely controlled, so that the cross-interference level between the antennas can be controlled.

[0009] In a possible implementation of the first aspect, the first position sequence and the second position sequence are obtained based on the at least one target position set with a first cyclic shift and a second cyclic shift, respectively, where the first cyclic shift corresponds to the first antenna port, the second cyclic shift corresponds to the second antenna port, and the first cyclic shift is different from the second cyclic shift.

[0010] Different cyclic shifts may be used to obtain different position sequences based on a same difference set, almost difference set or near difference set. There may be a correspondence between antenna port and cyclic shift, and different antenna ports correspond to different cyclic shifts, so that different position sequences can be obtained for different antenna ports based on the difference set, almost difference set or near difference set by using their respective cyclic shifts, which provides an easy way to generate different positions sequences for different antenna ports.

[0011] In a possible implementation of the first aspect, the at least one target position set is determined from position information which comprises multiple position sets, and each of the multiple position sets is a difference set, an almost difference set, or a near difference set.

[0012] The target difference set may be determined from multiple position sets, so that a suitable difference set, almost difference set or near difference set can be determined as the target position set to meet actual requirements or demands and adapt to different application scenarios.

[0013] In a possible implementation of the first aspect, the at least one target position set comprises a first target position set, and each of the multiple position sets has a first parameter, and the first target position set is determined from the position information based on the first parameter of the first target position set and a total number of REs for reference signal transmission.

[0014] When determining the first target position set from the position information, the first parameter of position set may be considered, so that the first target position set as determined is suitable for the total number of REs, thereby ensuring reasonable allocation of REs.

[0015] In a possible implementation of the first aspect, the first target position set is a position set with a first parameter closest to the total number of the REs for reference signal transmission among the multiple position sets.

[0016] A position set with a first parameter closest to the total number of REs for reference signal transmission may be determined as the first target position set, so that a position sequence corresponding to the determined position set may have a length closest to the total number of REs for reference signal transmission, which can ensure the control over the common REs and reduce operations, such as extension or shortening, which may be performed to make the length of a position sequence match with the total number of REs.

[0017] In a possible implementation of the first aspect, in a case that the position information comprises more than one position set with the first parameter closest to the total number of the REs for reference signal transmission, the first target position set is determined from the more than one position set based on a second parameter of the first target position set and a number of REs occupied by the first reference signal or the second reference signal.

[0018] Among the multiple position sets included in the position information, there may be two or more position sets having the same value of the first parameter. Therefore, when determining the first target position set, there mayexist more than one position set with the first parameter closest to the total number of REs for reference signal transmission. In this case, the second parameter for difference set, almost difference set or near difference set may be further considered, so that the first target position set, which is determined from the more than one position set with the closest first parameter, is suitable for the number of REs occupied by a reference signal. Since the first target position set is determined based on the first parameter and the total number of REs for reference signal transmission, as well as the second parameter and the number of REs occupied by a reference signal, a more suitable target position set can be determined, thereby realizing reasonable allocation of REs.

[0019] In a possible implementation of the first aspect, the first target position set is a position set with a second parameter closest to the number of the REs occupied by the first reference signal or the second reference signal.

[0020] From more than one position set with the closest first parameter, a position set with a second parameter closest to the number of REs occupied by a reference signal may be determined as the first target position set, so that the number of elements included in the first target position set may be closest to the number of REs occupied by a reference signal.

[0021] In a possible implementation of the first aspect, the first position sequence is obtained based on a position sequence and the first cyclic shift, and the second position sequence is obtained based on the position sequence and the second cyclic shift, where the position sequence is obtained based on the first target position set, the position sequence has a length equal to the first parameter of the first target position set, and elements of the position sequence with indices equal to elements of the first target position set have a value indicating presence of a reference signal.

[0022] A position sequence can be obtained based on the first target position set, where the length of position sequence is equal to the first parameter of the first target position set, and elements of the position sequence indicate whether a reference signal is present or not. The first and second position sequences can be obtained based on the position sequence and their corresponding cyclic shifts, respectively, and thus, the amount of overlap between the REs occupied by reference signals from different antenna ports can be precisely controlled, so that the crossinterference level between the antenna ports can be controlled and the transmission quality of the reference signals can be ensured, thereby improving channel estimation performance.

[0023] In a possible implementation of the first aspect, in a case that at least one first condition is satisfied, where the at least one first condition comprises the first parameter of the first target position set is greater than the total number of the REs for reference signal transmission, the first position sequence is obtained based on a shortened position sequence and the first cyclic shift, and the second position sequence is obtained based on the shortened position sequence and the second cyclic shift, where the shortened position sequence comprises part of elements of the position sequence, and the shortened position sequence has a length equal to the total number of the REs for reference signal transmission.

[0024] Some operation may be performed to obtain a shortened position sequence based on the position sequence when one or more first conditions are satisfied, for example, when the first parameter of the first target position set is greater than the total number of the REs for reference signal transmission, or the length of the position sequence is longer than the total number of the REs for reference signal transmission. Then, the first and second position sequences may be obtained based on the shortened position sequence and their respective cyclic shifts, respectively. The shortened position sequence may be obtained by, for example, cutting off one or more elements of the position sequence, so as to adapt to the total number of REs for reference signal transmission. In this way, the first and second position sequences can still be obtained even if there are only a small number of difference sets / almost difference sets / near difference sets, which provides a flexible way to determine the position sequence.

[0025] In a possible implementation of the first aspect, in a case that at least one second condition is satisfied, where the at least one second condition comprises the first parameter of the first target position set is less than the total number of the REs for reference signal transmission, the first position sequence is obtained based on an extendedposition sequence and the first cyclic shift, and the second position sequence is obtained based on the extended position sequence and the second cyclic shift, where the extended position sequence comprises the elements of the position sequence with part of the elements of the position sequence being repeated, and the extended position sequence has a length equal to the total number of the REs for reference signal transmission.

[0026] Some operation may be performed to obtain an extended position sequence based on the position sequence when one or more second conditions are satisfied, for example, when the first parameter of the first target position set is smaller than the total number of the REs for reference signal transmission, or the length of the position sequence is shorter than the total number of the REs for reference signal transmission. The extended position sequence may be obtained by, for example, repeating one or more elements of the position sequence, so as to adapt to the total number of REs for reference signal transmission, In this way, the position sequence can still be determined even if there are only a small number of difference sets / almost difference sets / near difference sets, which provides a flexible way to determine the position sequence.

[0027] In a possible implementation of the first aspect, positions of the first REs are indicated by the first position sequence and a first comb value; and positions of the second REs are indicated by the second position sequence and a second comb value.

[0028] The REs indicated by the first and second position sequences may be mapped with a comb-like structure, that is, the resource allocation can be implemented by applying the difference set / almost difference set / near difference set in combination with the comb-like structure. Thus, the number of common REs between REs occupied by reference signals from the first and second antenna ports can be precisely controlled and thus the crossinterference level between the antenna ports can be controlled, and meanwhile overhead for channel estimation can be reduced.

[0029] In a possible implementation of the first aspect, the first comb value is equal to the second comb value, the at least one target position set comprises a first target position set and / or a second target position set, where the at least one target position set is determined based on a first parameter of the one taiget position set, a total number of REs for reference signal transmission and the first comb value or the second comb value.

[0030] Different antenna ports may use a same comb value, that is, different antennas can correspond to the same comb-like structure. The resource allocation for different antennas can be determined based on the same target position set and different cyclic shifts, so as to control the cross-interference level between the antenna ports and ensure the transmission quality of the reference signals.

[0031] In a possible implementation of the first aspect, the first comb value is greater than the second comb value, and the first comb value is an integer multiple of the second comb value; where the at least one target position set comprises a first target position set and a second target position set, where the first target position set is determined based on a first parameter of the first target position set, a total number of REs for reference signal transmission and the first comb value, and the second target position set is determined based on a first parameter of the second target position set, the total number of the REs for reference signal transmission, the first comb value and the second comb value; where the first position sequence is obtained based on the first target position set and a third cyclic shift, and the second position sequence is obtained based on the first target position set, a fourth cyclic shift different from the third cyclic shift, and the second taiget position set.

[0032] The comb values for different antennas may be different, that is, different antennas may correspond to different comb-like structures, and the resource allocation for different antennas may be determined based on different target position sets and respective cyclic shifts, so as to control the cross-interference level between the antenna ports and ensure the transmission quality of the reference signals.

[0033] In a possible implementation of the first aspect, each of the at least one target position set has a thirdparameter, and the third parameter is related to a number of intersections between the REs on which the first reference signal is transmitted and the REs on which the second reference signal is transmitted.

[0034] Since the third parameter is related to the number of intersections between the REs occupied by the first reference signal and the second reference signal, thus the amount of overlap between the REs occupied by reference signals from different antenna ports can be obtained directly based on the third parameter of the target position set, and the cross-interference level between the antenna ports can be obtained more simply and easily.

[0035] In a possible implementation of the first aspect, the at least one target position set is determined by a base station and a user equipment, respectively, according to a pre-defined rule, or the at least one target position set is determined by a base station and indicated from the base station to a user equipment.

[0036] The at least one target position set may be determined or indicated in different ways. For example, the determination of the target position set may be performed by both the base station and the user equipment, and in this case, there may be no need for the base station to indicate the at least one target position set to the user equipment, and thus, signaling overhead can be saved. The at least one target position set may also be determined simply by the base station and then indicated to the user equipment. In this case, the base station may have full control over the resource allocation of reference signals, the use equipment does not need to determine the at least one target position set by itself, and thus, the rule or method for determining the target position set may not need to be configured in the user equipment, there may be less memory and computational capability requirements on the user equipment.

[0037] In a possible implementation of the first aspect, the first cyclic shift and the second cyclic shift are indicated from a base station to a user equipment.

[0038] The cyclic shifts for different antenna ports may be indicated by the base station to the user equipment, so that the use equipment can know the cyclic shifts of different antenna ports, and obtaining first and second position sequences based on the respective cyclic shifts.

[0039] In a possible implementation of the first aspect, the first reference signal and the second reference signal are transmitted from a base station to a user equipment, or from a user equipment to a base station.

[0040] The reference signal can be a downlink signal or an uplink signal, REs allocation using the difference set / almost difference set / near difference set can be applicable to the uplink and downlink channel estimation.

[0041] In a possible implementation of the first aspect, the position information is pre-stored in the user equipment, or obtained by the user equipment from the base station.

[0042] In a possible implementation of the first aspect, the position information is pre-stored in the base station.

[0043] In a possible implementation of the first aspect, the first cyclic shift and the second cyclic shift are carried in at least one of a media access control (MAC) control element (CE), downlink control information (DO) or radio resource control (RRC).

[0044] In this way, the cyclic shifts may be carried in different control channel.

[0045] In a possible implementation of the first aspect, the first cyclic shift and the second cyclic shift are allocated to the first antenna port and the second antenna port by a base station.

[0046] In a possible implementation of the first aspect, both the first reference signal and the second reference signal are sounding reference signals (SRSs); or, both of the first reference signal and the second reference signal are demodulation reference signals (DMRSs).

[0047] In a second aspect, a wireless communication method is provided by the present disclosure, and the method comprises: receiving a first reference signal using first resource elements (REs) associated with a first antenna port, where positions of the first REs are indicated by a first position sequence; receiving a second reference signal using second REs associated with a second antenna port, where positions of the second REs are indicated by a second position sequence;position set may be considered, so that the first target position set as determined is suitable for the total number of REs, thereby ensuring reasonable allocation of REs.

[0058] In a possible implementation of the second aspect, the first target position set is a position set with a first parameter closest to the total number of the REs for reference signal transmission among the multiple position sets.

[0059] A position set with a first parameter closest to the total number of REs for reference signal transmission may be determined as the first target position set, so that a position sequence corresponding to the determined position set may have a length closest to the total number of REs for reference signal transmission, which can ensure the control over the common REs and reduce operations, such as extension or shortening, which may be performed to make the length of a position sequence match with the total number of REs.

[0060] In a possible implementation of the second aspect, in a case that the position information comprises more than one position set with the first parameter closest to the total number of the REs for reference signal transmission, the first target position set is determined from the more than one position set based on a second parameter of the first target position set and a number of REs occupied by the first reference signal or the second reference signal.

[0001] Among the multiple position sets included in the position information, there may be two or more position sets having the same value of the first parameter. Therefore, when determining the first target position set, there may exist more than one position set with the first parameter closest to the total number of REs for reference signal transmission. In this case, the second parameter for difference set, almost difference set or near difference set may be further considered, so that the first target position set, which is determined from the more than one position set with the closest first parameter, is suitable for the number of REs occupied by a reference signal. Since the first taiget position set is determined based on the first parameter and the total number of REs for reference signal transmission, as well as the second parameter and the number of REs occupied by a reference signal, a more suitable target position set can be determined, thereby realizing reasonable allocation of REs.]0062] In a possible implementation of the second aspect, the first target position set is a position set with a second parameter closest to the number of the REs occupied by the first reference signal or the second reference signal.

[0063] From more than one position set with the closest first parameter, a position set with a second parameter closest to the number of REs occupied by a reference signal may be determined as the first target position set, so that the number of elements included in the first target position set may be closest to the number of REs occupied by a reference signal.

[0064] In a possible implementation of the second aspect, the first position sequence is obtained based on a position sequence and the first cyclic shift, and the second position sequence is obtained based on the position sequence and the second cyclic shift, where the position sequence is obtained based on the first target position set, the position sequence has a length equal to the first parameter of the first target position set, and elements of the position sequence with indices equal to elements of the first target position set have a value indicating presence of a reference signal.

[0065] A position sequence can be obtained based on the first target position set, where the length of position sequence is equal to the first parameter of the first target position set, and elements of the position sequence indicate whether a reference signal is present or not. The first and second position sequences can be obtained based on the position sequence and their corresponding cyclic shifts, respectively, and thus, the amount of overlap between the REs occupied by reference signals from different antenna ports can be precisely controlled, so that the crossinterference level between the antenna ports can be controlled and the transmission quality of the reference signals can be ensured, thereby improving channel estimation performance.

[0066] In a possible implementation of the second aspect, in a case that at least one first condition is satisfied, where the at least one first condition comprises the first parameter of the first target position set is greater than thetotal number of the REs for reference signal transmission, the first position sequence is obtained based on a shortened position sequence and the first cyclic shift, and the second position sequence is obtained based on the shortened position sequence and the second cyclic shift, where the shortened position sequence comprises part of elements of the position sequence, and the shortened position sequence has a length equal to the total number of the REs for reference signal transmission.

[0067] Some operation may be performed to obtain a shortened position sequence based on the position sequence when one or more first conditions are satisfied, for example, when the first parameter of the first target position set is greater than the total number of the REs for reference signal transmission, or the length of the position sequence is longer than the total number of the REs for reference signal transmission. Then, the first and second position sequences may be obtained based on the shortened position sequence and their respective cyclic shifts, respectively. The shortened position sequence may be obtained by, for example, cutting off one or more elements of the position sequence, so as to adapt to the total number of REs for reference signal transmission. In this way, the first and second position sequences can still be obtained even if there are only a small number of difference sets / almost difference sets / near difference sets, which provides a flexible way to determine the position sequence.

[0068] In a possible implementation of the second aspect, in a case that at least one second condition is satisfied, where the at least one second condition comprises the first parameter of the first target position set is less than the total number of the REs for reference signal transmission, the first position sequence is obtained based on an extended position sequence and the first cyclic shift, and the second position sequence is obtained based on the extended position sequence and the second cyclic shift, where the extended position sequence comprises the elements of the position sequence with part of the elements of the position sequence being repeated, and the extended position sequence has a length equal to the total number of the REs for reference signal transmission.

[0069] Some operation may be performed to obtain an extended position sequence based on the position sequence when one or more second conditions are satisfied, for example, when the first parameter of the first target position set is smaller than the total number of the REs for reference signal transmission, or the length of the position sequence is shorter than the total number of the REs for reference signal transmission. The extended position sequence may be obtained by, for example, repeating one or more elements of the position sequence, so as to adapt to the total number of REs for reference signal transmission, In this way, the position sequence can still be determined even if there are only a small number of difference sets / almost difference sets / near difference sets, which provides a flexible way to determine the position sequence.

[0070] In a possible implementation of the second aspect, positions of the first REs are indicated by the first position sequence and a first comb value; and positions of the second REs are indicated by the second position sequence and a second comb value.

[0071] The REs indicated by the first and second position sequences may be mapped with a comb-like structure, that is, the resource allocation can be implemented by applying the difference set / almost difference set / near difference set in combination with the comb-like structure. Thus, the number of common REs between REs occupied by reference signals from the first and second antenna ports can be precisely controlled and thus the crossinterference level between the antenna ports can be controlled, and meanwhile overhead for channel estimation can be reduced.

[0072] In a possible implementation of the second aspect, the first comb value is equal to the second comb value, the at least one target position set comprises a first target position set and / or a second target position set, where the at least one target position set is determined based on a first parameter of the one target position set, a total number of REs for reference signal transmission and the first comb value or the second comb value.

[0073] Different antenna ports may use a same comb value, that is, different antennas can correspond to the same comb-like structure. The resource allocation for different antennas can be determined based on the same targetposition set and different cyclic shifts, so as to control the cross-interference level between the antenna ports and ensure the transmission quality of the reference signals.

[0074] In a possible implementation of the second aspect, the first comb value is greater than the second comb value, and the first comb value is an integer multiple of the second comb value; where the at least one target position set comprises a first taiget position set and a second target position set, where the first target position set is determined based on a first parameter of the first target position set, a total number of REs for reference signal transmission and the first comb value, and the second taiget position set is determined based on a first parameter of the second target position set, the total number of the REs for reference signal transmission, the first comb value and the second comb value; where the first position sequence is obtained based on the first target position set and a third cyclic shift, and the second position sequence is obtained based on the first taiget position set, a fourth cyclic shift different from the third cyclic shift, and the second target position set.

[0075] The comb values for different antennas may be different, that is, different antennas may correspond to different comb-like structures, and the resource allocation for different antennas may be determined based on different target position sets and respective cyclic shifts, so as to control the cross-interference level between the antenna ports and ensure the transmission quality of the reference signals.

[0076] In a possible implementation of the second aspect, each of the at least one target position set has a third parameter, and the third parameter is related to a number of intersections between the REs on which the first reference signal is transmitted and the REs on which the second reference signal is transmitted.

[0077] Since the third parameter is related to the number of intersections between the REs occupied by the first reference signal and the second reference signal, thus the amount of overlap between the REs occupied by reference signals from different antenna ports can be obtained directly based on the third parameter of the taiget position set, and the cross-interference level between the antenna ports can be obtained more simply and easily.

[0078] In a possible implementation of the second aspect, the at least one target position set is determined by a base station and a user equipment, respectively, according to a pre-defined rule, or the at least one target position set is determined by a base station and indicated from the base station to a user equipment.

[0079] The at least one target position set may be determined or indicated in different ways. For example, the determination of the taiget position set may be performed by both the base station and the user equipment, and in this case, there may be no need for the base station to indicate the at least one target position set to the user equipment, and thus, signaling overhead can be saved. The at least one target position set may also be determined simply by the base station and then indicated to the user equipment. In this case, the base station may have full control over the resource allocation of reference signals, the use equipment does not need to determine the at least one target position set by itself, and thus, the rule or method for determining the target position set may not need to be configured in the user equipment, there may be less memory and computational capability requirements on the user equipment.

[0080] In a possible implementation of the second aspect, the first cyclic shift and the second cyclic shift are indicated from a base station to a user equipment.

[0081] The cyclic shifts for different antenna ports may be indicated by the base station to the user equipment, so that the use equipment can know the cyclic shifts of different antenna ports, and obtaining first and second position sequences based on the respective cyclic shifts.

[0082] In a possible implementation of the second aspect, the first reference signal and the second reference signal are transmitted from a base station to a user equipment, or from a user equipment to a base station.

[0083] The reference signal can be a downlink signal or an uplink signal, REs allocation using the difference set / almost difference set / near difference set can be applicable to the uplink and downlink channel estimation.equipment, or obtained by the user equipment from the base station.

[0085] In a possible implementation of the second aspect, the position information is pre-stored in the base station.

[0086] In a possible implementation of the second aspect, the first cyclic shift and the second cyclic shift are carried in at least one of a media access control (MAC) control element (CE), downlink control information (DCI) or radio resource control (RRC).

[0087] In this way, the cyclic shifts may be carried in different control channel.

[0088] In a possible implementation of the second aspect, the first cyclic shift and the second cyclic shift are allocated to the first antenna port and the second antenna port by a base station.

[0089] In a possible implementation of the second aspect, both the first reference signal and the second reference signal are sounding reference signals (SRSs); or, both of the first reference signal and the second reference signal are demodulation reference signals (DMRSs).]0090] In a third aspect, a wireless communication apparatus is provided by the present disclosure, and the apparatus includes various modules configured to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect.

[0091] In a fourth aspect, a wireless communication apparatus is provided by the present disclosure, and the apparatus includes various modules configured to execute the wireless communication method according to the second aspect or any possible implementation of the second aspect.

[0092] In a fifth aspect, a wireless communication apparatus is provided by the present disclosure, and the apparatus includes at least one processor, where the at least one processor is configured to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0093] In a possible implementation of the fifth aspect, the above apparatus may further include a memory, and the memory stores instructions that cause the at least one processor to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0094] In a sixth aspect, a wireless communication apparatus is provided by the present disclosure, and the apparatus is configured to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0095] In a seventh aspect, a first network element is provided by the present disclosure, and the first network element includes processing circuitry for executing the wireless communication method according to the first aspect or any possible implementation of the first aspect.

[0096] In an eighth aspect, a second network element is provided by the present disclosure, and the second network element includes processing circuitry for executing the wireless communication method according to the second aspect or any possible implementation of the second aspect.

[0097] In a ninth aspect, a wireless communication system is provided by the present disclosure, and the wireless communication system includes the first network element according to the seventh aspect and the second network element according to the eighth aspect.

[0098] In a tenth aspect, a chip is provided by the present disclosure, and the chip includes an input / output (I / O) interface and a processor, where the processor is configured to call and run computer execution instructions stored in a memory, to enable a device installing with the chip to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0099] In an eleventh aspect, a computer-readable medium is provided by the present disclosure, and the computer-readable medium includes storing computer execution instructions which, when executed by a processor, causes the processor to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect

[0100] In a twelfth aspect, a computer program product is provided by the present disclosure, and the computer program product includes computer execution instructions which, when executed by a processor, causes the processor to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0101] In a thirteenth aspect, a computer program is provided by the present disclosure, the computer program comprises computer execution instructions which, when executed by a processor, cause the processor to execute the wireless communication method according to the first aspect or any possible implementation of the first aspect or according to the second aspect or any possible implementation of the second aspect.

[0102] A wireless communication method and related apparatus are provided by the present disclosure. A first reference signal is transmitted by using first resource elements (REs) associated with a first antenna port , where positions of the first REs are indicated by a first position sequence; a second reference signal is transmitted by using second REs associated with a second antenna port, where positions of the second REs are indicated by a second position sequence; where the first position sequence and the second position sequence are obtained based on at least one target position set, each of the at least one target position set is a difference set, an almost difference set or a near difference set, and where the first antenna port is different from the second antenna port and the first position sequence is different from the second position sequence. Positions of REs occupied by a reference signal may be indicated by a position sequence. Position sequences are different for different antenna ports, and thus complete overlapping between REs occupied by reference signals from different antenna ports can be avoided, which may enable reasonable resource allocation. In addition, at least one of the difference set, the almost difference set and the near difference set is used to obtain the position sequences for different antenna ports, and thus, the amount of overlap between REs occupied by reference signals from different antenna ports can be precisely controlled, so that the crossinterference level between the antenna ports can be controlled and the transmission quality of the reference signals can be ensured, thereby improving channel estimation performance.BRIEF DESCRIPTION OF DRAWINGS

[0103] The accompanying drawings are used to provide a further understanding of the present disclosure, constitute a part of the specification, and are used to explain the present disclosure together with the following specific embodiments, but should not be construed as limiting the present disclosure.

[0104] FIG. 1 is a schematic illustration of a communication system according to one or more embodiments of the present disclosure.

[0105] FIG. 2 is another schematic illustration of a communication system according to one or more embodiments of the present disclosure.

[0106] FIG. 3 is a schematic illustration of basic component structure of a communication system according to one or more embodiments of the present disclosure.

[0107] FIG. 4 illustrates a block diagram of a device in a communication system according to one or more embodiments of the present disclosure.

[0108] FIG. 5 is a schematic illustration of an example reference signal allocation in related art.

[0109] FIG. 6 is a schematic illustration of an effect of reference signal allocation shown in FIG. 5.

[0110] FIG. 7 is a schematic illustration of an effect of reference signal allocation shown in FIG. 5 for a large comb value.

[0111] FIG. 8 is a schematic illustration of multiplexing sequences of several antennas on the same subcarriers in related art.

[0112] FIG. 9 is a schematic illustration of inverse discrete division multiplexing (IDFT) of a sampling pattern in related art.

[0113] FIG. 10 is a schematic illustration of channel impulse response sampled regularly and irregularly in related art.

[0114] FIG. 11 is a schematic illustration of an example reference signal allocation for multi-antennas in related art.

[0115] FIG. 12 is a schematic illustration of another example reference signal allocation for multi-antennas in related art.

[0116] FIG. 13 is a schematic illustration of inverse discrete division multiplexing (IDFT) of another sampling pattern according to one or more embodiments of the present disclosure.

[0117] FIG. 14 is a schematic flowchart of a wireless communication method according to one or more embodiments of the present disclosure.

[0118] FIG. 15A is a schematic illustration of an example reference signal allocation using a difference set according to one or more embodiments of the present disclosure.

[0119] FIG. 15B shows an example process of extension operation on a position sequence.

[0120] FIG. 16 is a schematic illustration of an example reference signal allocation using a difference set according to one or more embodiments of the present disclosure.

[0121] FIG. 17 is a schematic illustration of an example reference signal allocation using a difference set according to one or more embodiments of the present disclosure.

[0122] FIG. 18 is a schematic illustration of an example reference signal allocation by combining a difference set combined with a comb-like structure according to one or more embodiments of the present disclosure.

[0123] FIG. 19 is a schematic illustration of another example reference signal allocation by combining a difference set combined with a comb-like structure according to one or more embodiments of the present disclosure.

[0124] FIG. 20 shows a schematic flowchart of another wireless communication method according to one or more embodiments of the present disclosure.

[0125] FIG. 21 is a block diagram of a wireless communication apparatus according to one or more embodiments of the present disclosure.

[0126] FIG. 22 is a block diagram of another wireless communication apparatus according to one or more embodiments of the present disclosure.

[0127] FIG. 23 is a schematic structural diagram of a wireless communication apparatus according to one or more embodiments of the present disclosure.DESCRIPTION OF EMBODIMENTS

[0128] In the following description, reference is made to the accompanying figures, which form part of the present disclosure, and which show, by way of illustration, specific aspects of embodiments of the present disclosure or specific aspects in which embodiments of the present disclosure may be used. It is understood that embodiments of the present disclosure may be used in other aspects and include structural or logical changes not depicted in the figures. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.

[0129] To assist in understanding the present disclosure, examples of wireless communication systems and devices are described below.

[0130] Referring to FIG. 1, as an illustrative example without limitation, a simplified schematic illustration of a communication system is provided. The communication system 100 includes a radio access network 120. The radio access network 120 may be a next generation (e.g., sixth generation (6G) or later) radio access network, or a legacy (e.g., 5G, 4G, 3G or 2G) radio access network. One or more communication electric device (ED) llOa-llOj (generically referred to as 110) may be interconnected to one another or connected to one or more network nodes (170a, 170b, generically referred to as 170) in the radio access network 120. A core network 130 may be a part of the communication system and may be dependent or independent of the radio access technology used in the communication system 100. Also, the communication system 100 includes a public switched telephone network (PSTN) 140, the internet 150, and other networks 160.

[0131] FIG. 2 illustrates an example communication system 100. In general, the communication system 100 enables multiple wireless or wired elements to communicate data and other content. The purpose of the communication system 100 may be to provide content, such as voice, data, video, and / or text, via broadcast, multicast and unicast, etc. The communication system 100 may operate by sharing resources, such as carrier spectrum bandwidth, between its constituent elements. The communication system 100 may include a terrestrial communication system and / or a non-terrestrial communication system. The communication system 100 may provide a wide range of communication services and applications (such as earth monitoring, remote sensing, passive sensing and positioning, navigation and tracking, autonomous delivery and mobility, etc.). The communication system 100 may provide a high degree of availability and robustness through a joint operation of the terrestrial communication system and the non-terrestrial communication system. For example, integrating a non-terrestrial communication system (or components thereof) into a terrestrial communication system can result in what may be considered a heterogeneous network including multiple layers. Compared to conventional communication networks, the heterogeneous network may achieve better overall performance through efficient multi-link joint operation, more flexible functionality sharing, and faster physical layer link switching between terrestrial networks and non-terrestrial networks.

[0132] The terrestrial communication system and the non-terrestrial communication system could be considered sub-systems of the communication system. In the example shown, the communication system 100 includes electronic devices (ED) HOa-llOd (generically referred to as ED 110), radio access networks (RANs) 120a-120b, nonterrestrial communication network 120c, a core network 130, a public switched telephone network (PSTN) 140, the internet 150, and other networks 160. The RANs 120a- 120b include respective base stations (BSs) 170a- 170b, which may be generically referred to as terrestrial transmit and receive points (T-TRPs) 170a- 170b. The non-terrestrial communication network 120c includes an access node 120c, which may be generically referred to as anon-terrestrial transmit and receive point (NT-TRP) 172.

[0133] Any ED 110 may be alternatively or additionally configured to interface, access, or communicate with any other T-TRP 170a-170b and NT-TRP 172, the internet 150, the core network 130, the PSTN 140, the other networks 160, or any combination of the preceding. In some examples, ED 110a may communicate an uplink and / or downlink transmission over an interface 190a with T-TRP 170a. In some examples, the EDs 110a, 110b, 110c and 1 lOd may also communicate directly with one another via one or more sidelink air interfaces 190b. In some examples, ED 1 lOd may communicate an uplink and / or downlink transmission over an interface 190c with NT-TRP 172.

[0134] The air interfaces 190a and 190b may use similar communication technology, such as any suitable radio access technology. For example, the communication system 100 may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or single-carrier FDMA (SC-FDMA) in the air interfaces 190a and190b. The air interfaces 190a and 190b may utilize other higher dimension signal spaces, which may involve a combination of orthogonal and / or non-orthogonal dimensions.

[0135] The air interface 190c can enable communication between the ED HOd and one or multiple NT-TRPs 172 via a wireless link or simply a link. In some examples, the link is a dedicated connection for unicast transmission, a connection for broadcast transmission, or a connection between a group of EDs and one or multiple NT-TRPs for multicast transmission.

[0136] The RANs 120a and 120b are in communication with the core network 130 to provide the EDs 110a 110b, and 110c with various services such as voice, data, and other services. The RANs 120a and 120b and / or the core network 130 may be in direct or indirect communication with one or more other RANs (not shown), which may or may not be directly served by core network 130, and may or may not employ the same radio access technology as RAN 120a, RAN 120b or both. The core network 130 may also serve as a gateway access between (i) the RANs 120a and 120b or EDs 110a 110b, and 110c or both, and (ii) other networks (such as the PSTN 140, the internet 150, and the other networks 160). In addition, some or all of the EDs 110a 110b, and 110c may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies and / or protocols. Instead of wireless communication (or in addition thereto), the EDs 110a 110b, and 110c may communicate via wired communication channels to a service provider or switch (not shown), and to the internet 150. PSTN 140 may include circuit switched telephone networks for providing plain old telephone service (POTS). Internet 150 may include a network of computers and subnets (intranets) or both, and incorporate protocols, such as Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP). EDs 110a 110b, and 110c may be multimode devices capable of operation according to multiple radio access technologies, and incorporate multiple transceivers necessary to support such.

[0137] FIG. 3 illustrates another example of an ED 110 and a base station 170a, 170b and / or 170c. The ED 110 is used to connect persons, objects, machines, etc. The ED 110 may be widely used in various scenarios, for example, cellular communications, device-to-device (D2D), vehicle to everything (V2X), peer-to-peer (P2P), machine-to- machine (M2M), machine-type communications (MTC), internet of things (IOT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and mobility, etc.

[0138] Each ED 110 represents any suitable end user device for wireless operation and may include such devices(or may be referred to) as a user equipment / device (UE), a wireless transmit / receive unit (WTRU), a mobile station, a fixed or mobile subscriber unit, a cellular telephone, a station (STA), a machine type communication (MTC) device, a personal digital assistant (PDA), a smartphone, a laptop, a computer, a tablet, a wireless sensor, a consumer electronics device, a smart book, a vehicle, a car, a truck, a bus, a train, or an loT device, an industrial device, or apparatus (e.g. communication module, modem, or chip) in the forgoing devices, among other possibilities. Future generation EDs 110 may be referred to using other terms. The base station 170a and 170b is a T-TRP and will hereafter be referred to as T-TRP 170. Also shown in FIG. 3, a NT-TRP will hereafter be referred to as NT-TRP 172. Each ED 110 connected to T-TRP 170 and / or NT-TRP 172 can be dynamically or semi-statically tumed-on (i.e., established, activated, or enabled), turned-off (i.e., released, deactivated, or disabled) and / or configured in response to one of more of: connection availability and connection necessity.

[0139] The ED 110 includes a transmitter 201 and a receiver 203 coupled to one or more antennas 204. Only one antenna 204 is illustrated. One, some, or all of the antennas may alternatively be panels. The transmitter 201 and the receiver 203 may be integrated, e.g. as a transceiver. The transceiver is configured to modulate data or other content for transmission by at least one antenna 204 or network interface controller (NIC). The transceiver is alsoany suitable structure for generating signals for wireless or wired transmission and / or processing signals received wirelessly or by wire. Each antenna 204 includes any suitable structure for transmitting and / or receiving wireless or wired signals.

[0140] The ED 110 includes at least one memory 208. The memory 208 stores instructions and data used, generated, or collected by the ED 110. For example, the memory 208 could store software instructions or modules configured to implement some or all of the functionality and / or embodiments described herein and that are executed by the processing unit(s) 210. Each memory 208 includes any suitable volatile and / or non-volatile storage and retrieval device(s). Any suitable type of memory may be used, such as random access memory (RAM), read only memory (ROM), hard disk, optical disc, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, on-processor cache, and the like.

[0141] The ED 110 may further include one or more input / output devices (not shown) or interfaces (such as a wired interface to the internet 150 in FIG. 1). The input / output devices permit interaction with a user or other devices in the network. Each input / output device includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen, including network interface communications.

[0142] The ED 110 further includes a processor 210 for performing operations including those related to preparing a transmission for uplink transmission to the NT-TRP 172 and / or T-TRP 170, those related to processing downlink transmissions received from the NT-TRP 172 and / or T-TRP 170, and those related to processing sidelink transmission to and from another ED 110. Processing operations related to preparing a transmission for uplink transmission may include operations such as encoding, modulating, transmit beamforming, and generating symbols for transmission. Processing operations related to processing downlink transmissions may include operations such as receive beamforming, demodulating and decoding received symbols. Depending upon the embodiment, a downlink transmission may be received by the receiver 203, possibly using receive beamforming, and the processor 210 may extract signaling from the downlink transmission (e.g. by detecting and / or decoding the signaling). An example of signaling may be a reference signal transmitted by NT-TRP 172 and / or T-TRP 170. In some embodiments, the processor 276 implements the transmit beamforming and / or receive beamforming based on the indication of beam direction, e.g. beam angle information (BAI), received from T-TRP 170. In some embodiments, the processor 210 may perform operations relating to network access (e.g. initial access) and / or downlink synchronization, such as operations relating to detecting a synchronization sequence, decoding and obtaining the system information, etc. In some embodiments, the processor 210 may perform channel estimation, e.g. using a reference signal received from the NT-TRP 172 and / or T-TRP 170.

[0143] Although not illustrated, the processor 210 may form part of the transmitter 201 and / or receiver 203. Although not illustrated, the memory 208 may form part of the processor 210.

[0144] The processor 210, and the processing components of the transmitter 201 and receiver 203 may each be implemented by the same or different one or more processors that are configured to execute instructions stored in a memory (e.g. in memory 208). Alternatively, some or all of the processor 210, and the processing components of the transmitter 201 and receiver 203 may be implemented using dedicated circuitry, such as a programmed field- programmable gate array (FPGA), a graphical processing unit (GPU), or an application-specific integrated circuit (ASIC).

[0145] The T-TRP 170 may be known by other names in some implementations, such as a base station, a base transceiver station (BTS), a radio base station, a network node, a network device, a device on the network side, a transmit / receive node, a Node B, an evolved NodeB (eNodeB or eNB), a Home eNodeB, a next Generation NodeB (gNB), a transmission point (TP) ), a site controller, an access point (AP), or a wireless router, a relay station, a remote radio head, a terrestrial node, a terrestrial network device, or a terrestrial base station, base band unit (BBU),remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distribute unit (DU), positioning node, among other possibilities. The T-TRP 170 may be macro BSs, pico BSs, relay node, donor node, or the like, or combinations thereof. The T-TRP 170 may refer to the forging devices or apparatus (e.g. communication module, modem, or chip) in the forgoing devices.

[0146] In some embodiments, the parts of the T-TRP 170 may be distributed. For example, some of the modules of the T-TRP 170 may be located remote from the equipment housing the antennas of the T-TRP 170, and may be coupled to the equipment housing the antennas over a communication link (not shown) sometimes known as front haul, such as common public radio interface (CPRI). Therefore, in some embodiments, the term T-TRP 170 may also refer to modules on the network side that perform processing operations, such as determining the location of the ED 110, resource allocation (scheduling), message generation, and encoding / decoding, and that are not necessarily part of the equipment housing the antennas of the T-TRP 170. The modules may also be coupled to other T-TRPs. In some embodiments, the T-TRP 170 may actually be a plurality of T-TRPs that are operating together to serve the ED 110, e.g. through coordinated multipoint transmissions.

[0147] The T-TRP 170 includes at least one transmitter 252 and at least one receiver 254 coupled to one or more antennas 256. Only one antenna 256 is illustrated. One, some, or all of the antennas may alternatively be panels. The transmitter 252 and the receiver 254 may be integrated as a transceiver. The T-TRP 170 further includes a processor 260 for performing operations including those related to: preparing a transmission for downlink transmission to the ED 110, processing an uplink transmission received from the ED 110, preparing a transmission for backhaul transmission to NT-TRP 172, and processing a transmission received over backhaul from the NT-TRP 172. Processing operations related to preparing a transmission for downlink or backhaul transmission may include operations such as encoding, modulating, precoding (e.g. MIMO precoding), transmit beamforming, and generating symbols for transmission. Processing operations related to processing received transmissions in the uplink or over backhaul may include operations such as receive beamforming, and demodulating and decoding received symbols. The processor 260 may also perform operations relating to network access (e.g. initial access) and / or downlink synchronization, such as generating the content of synchronization signal blocks (SSBs), generating the system information, etc. In some embodiments, the processor 260 also generates the indication of beam direction, e.g. BAI, which may be scheduled for transmission by scheduler 253. The processor 260 performs other network-side processing operations described herein, such as determining the location of the ED 110, determining where to deploy NT-TRP 172, etc. In some embodiments, the processor 260 may generate signaling, e.g. to configure one or more parameters of the ED 110 and / or one or more parameters of the NT-TRP 172. Any signaling generated by the processor 260 is sent by the transmitter 252. Note that “signaling”, as used herein, may alternatively be called control signaling. Dynamic signaling may be transmitted in a control channel, e.g. a physical downlink control channel (PDCCH), and static or semi-static higher layer signaling may be included in a packet transmitted in a data channel, e.g. in a physical downlink shared channel (PDSCH).

[0148] A scheduler 253 may be coupled to the processor 260. The scheduler 253 may be included within or operated separately from the T-TRP 170, which may schedule uplink, downlink, and / or backhaul transmissions, including issuing scheduling grants and / or configuring scheduling-free (“configured grant”) resources. The T-TRP 170 further includes a memory 258 for storing information and data. The memory 258 stores instructions and data used, generated, or collected by the T-TRP 170. For example, the memory 258 could store software instructions or modules configured to implement some or all of the fiinctionality and / or embodiments described herein and that are executed by the processor 260.

[0149] Although not illustrated, the processor 260 may form part of the transmitter 252 and / or receiver 254. Also, although not illustrated, the processor 260 may implement the scheduler 253. Although not illustrated, the memory 258 may form part of the processor 260.

[0150] The processor 260, the scheduler 253, and the processing components of the transmitter 252 and receiver254 may each be implemented by the same or different one or more processors that are configured to execute instructions stored in a memory, e.g. in memory 258. Alternatively, some or all of the processor 260, the scheduler 253, and the processing components of the transmitter 252 and receiver 254 may be implemented using dedicated circuitry, such as a FPGA, a GPU, or an ASIC.

[0151] Although the NT-TRP 172 is illustrated as a drone only as an example, the NT-TRP 172 may be implemented in any suitable non-terrestrial form, it should be noted that the NT-TRP 172 may be removed in some cases. Also, the NT-TRP 172 may be known by other names in some implementations, such as a non-terrestrial node, a non-terrestrial network device, or a non-terrestrial base station. The NT-TRP 172 includes a transmitter 272 and a receiver 274 coupled to one or more antennas 280. Only one antenna 280 is illustrated. One, some, or all of the antennas may alternatively be panels. The transmitter 272 and the receiver 274 may be integrated as a transceiver. The NT-TRP 172 further includes a processor 276 for performing operations including those related to: preparing a transmission for downlink transmission to the ED 110, processing an uplink transmission received from the ED 110, preparing a transmission for backhaul transmission to T-TRP 170, and processing a transmission received over backhaul from the T-TRP 170. Processing operations related to preparing a transmission for downlink or backhaul transmission may include operations such as encoding, modulating, preceding (e.g. MIMO precoding), transmit beamforming, and generating symbols for transmission. Processing operations related to processing received transmissions in the uplink or over backhaul may include operations such as receive beamforming, and demodulating and decoding received symbols. In some embodiments, the processor 276 implements the transmit beamforming and / or receive beamforming based on beam direction information (e.g. BAI) received from T-TRP 170. In some embodiments, the processor 276 may generate signaling, e.g. to configure one or more parameters of the ED 110. In some embodiments, the NT-TRP 172 implements physical layer processing, but does not implement higher layer functions such as functions at the medium access control (MAC) or radio link control (RLC) layer. As this is only an example, more generally, the NT-TRP 172 may implement higher layer functions in addition to physical layer processing.

[0152] The NT-TRP 172 further includes a memory 278 for storing information and data. Although not illustrated, the processor 276 may form part of the transmitter 272 and / or receiver 274. Although not illustrated, the memory 278 may form part of the processor 276.

[0153] The processor 276 and the processing components of the transmitter 272 and receiver 274 may each be implemented by the same or different one or more processors that are configured to execute instructions stored in a memory, e.g. in memory 278. Alternatively, some or all of the processor 276 and the processing components of the transmitter 272 and receiver 274 may be implemented using dedicated circuitry, such as a programmed FPGA, a GPU, or an ASIC. In some embodiments, the NT-TRP 172 may actually be a plurality of NT-TRPs that are operating together to serve the ED 110, e.g. through coordinated multipoint transmissions.

[0154] The T-TRP 170, the NT-TRP 172, and / or the ED 110 may include other components, but these have been omitted for the sake of clarity.

[0155] One or more steps of the embodiment methods provided herein may be performed by corresponding units or modules, according to FIG. 4. FIG. 4 illustrates units or modules in a device, such as in ED 110, in T-TRP 170, or in NT-TRP 172. For example, a signal may be transmitted by a transmitting unit or a transmitting module. For example, a signal may be transmitted by a transmitting unit or a transmitting module. A signal may be received by a receiving unit or a receiving module. A signal may be processed by a processing unit or a processing module. Other steps may be performed by an artificial intelligence (Al) or machine learning (ML) module, which can be chosen or removed according to actual requirements. The respective units or modules may be implemented using hardware, one or more components or devices that execute software, or a combination thereof. For instance, one ormore of the units or modules may be an integrated circuit, such as a programmed FPGA, a GPU, or an ASIC. It will be appreciated that where the modules are implemented using software for execution by a processor for example, they may be retrieved by a processor, in whole or part as needed, individually or together for processing, in single or multiple instances, and that the modules themselves may include instructions for further deployment and instantiation. It should be noted that, the modules shown in FIG. 4 are only illustrative and should not be construed as limitations to the embodiments of the present disclosure, more or less modules may be included in the device, which is not limited here. For example, the transmitting module and the receiving module may be replaced with one transceiving module. For another example, the ML module can be included or excluded from the device, depending on actual needs.(0156] Additional details regarding the EDs 110, T-TRP 170, and NT-TRP 172 are known to those of skill in the art. As such, these details are omitted here.

[0157] The above describes possible scenarios or generalized description of the examples of the present disclosure, the motivation and technical concepts of the present disclosure are illustrated in the following.

[0158] First, example concepts of some terms will be introduced below.

[0159] Delay spread: the difference between the time of arrivals of the earliest and the latest beams.Downlink: the channel from BS to UE.Uplink: the channel from UE to BSResource Unit (RU): one or multiple continuous or discontinuous REs (subcarriers).Resource Element (RE): one bin of time-subcarrier resource grid, that is, one subcarrier-one time domain symbol resource atom, in terms of resource allocation, the smallest possible piece of resource.Resource Block (RB): a set of 12 Resource Elements with subsequent subcarrier number, located continuously in frequency domain.

[0160] Multi-frequency transmission schemes are extremely popular in modem wireless communications. One of the classical multi-frequency schemes is orthogonal frequency division multiplexing (OFDM), used in Wi-Fi, 4G LTE and 5G NR. OFDM allows to transmit data on several frequencies at the same time. These are called subcarriers.

[0161] To estimate the channel, some subcarriers are used not for data transmission, but for special signals called pilots or Reference Signals. The amount of resources in time and frequency required for channel estimation is called channel estimation overhead (or simply overhead). The overhead is measured in resource elements (REs).

[0162] In related art, it is demonstrated that the overhead can be decreased if compressed sensing algorithms are used. Particularly, it is shown that the level of self-interference is reduced when positions of reference signals are random. However, usage of popular random numbers generators is impractical because of high computational complexity.

[0163] Another problem arises when reference signals with quasi-random positions are transmitted from several antennas at the same time. In such case, there can be overlap between reference signals from different antennas / antenna ports, e.g. some parts of them can be transmitted on the same subcarriers. The overlap between reference signals from two different antennas may also be called as common subcarriers, common REs, overlapping REs, intersections between reference signals from two different antennas in the following, which refer to subcarriers or REs that are occupied by both reference signals from two different antennas.

[0164] The number of common subcarriers between reference signals from two different antennas determines the level of cross-interference between these two antennas. If positions of the reference signals are chosen to minimize cross-interference between these two antennas, self-interference of each antenna can be increased. In related art, this problem is approached by numerically solving complex optimization tasks and obtaining good reference signal positions for every antenna. However, this solution is valid only for a given set of parameters, i.e. given total number of subcarriers, number of antennas and number of reference signal positions for each antenna. If(un— ui) mod N,n #= I (1) take all possible nonzero values 1, 2, 3, ... N-l each exactly A times.

[0181] A set of integer numbers u = {u1;...,uD} is called an (N, D,A,t) almost difference set if all D(D —1) differences(un- uj mod N, n =# 1 (2) take t possible non-zero values exactly A times, and the remaining N — 1 — t possible nonzero elements exactly A + 1 times.

[0182] For an even integer N > 4, for position integers D, A, a set of integer numbers u = {tij, ...,uD) is called an (N, D,A) near difference set if all D(D - l) differences(Un — Ui) mod N, n * I (3) take all possible nonzero values 1,2,3, ... N-l except (N / 2~)mod(N) exactly A times and do not take the value (N / 2)mod(7V).

[0183] There is a concept of optimal sampling in terms of minimizing the maximal self-interference level. For a signal with N subcarriers measured at Npsubcarriers (sampling pattern of length N with Npsubcarriers) the optimal self-interference level is determined by Welch bound:

[0184] If sampling reaches this value, all cross-interference terms have equal amplitude, as shown in FIG. 13. FIG. 13 shows IDFT of an example optimal sampling pattern which has a constant amplitude except the main peak. This amplitude value is equal to the Welch bound. Though the average value of self-interference is the same as for random pattern in FIG. 9, the maximal level of interference is much lower. Such sampling pattern can be achieved if the indices of pilot subcarriers form a DS. DS is available for a limited set of parameters N and D. ADS is available for a larger set of parameters (N and D); if ADS is used, there are multiple amplitude levels and self-interference is not optimal, but close to optimal. NDS may be another example of suboptimal solution, and is also available for a larger set of parameters.

[0185] In a possible implementation of the present disclosure, consider a design where the pattern of each antenna out of NTXis formed by a DS and all patterns have zero intersection. In other words, each antenna’s pattern has length IV, contains Npnon-zero elements, reaches Welch bound and all patterns have zero intersection. Such constructions are available for a few specific N, Npand NTXvalues and there would be no general formula or general construction method to obtain them. For a lot of values N, Npand NTX, such constructions do not exist. Some particular examples can be constructed when each antenna has different number of pilot subcarriers Np l, Np,2 —NP,NTXeach antenna uses different DSs. In such case the pattern of each antenna will reach Welsh bound and have optimal self-interference, but the cross-interference cannot be controlled.

[0186] The present disclosure proposes a method to generate sampling pattern of reference signal for multiantenna applications by using a DS, an ADS, or an NDS. The solutions of the present disclosure mainly rely on one important property of DS / ADS / NDS. If there are two (N, D, A) DSs and the second one is formed as the cyclic shift of the first one, they will have exactly A intersections. If there are two (N, D, A, t) ADSs and the second one is constructed as the cyclic shift of the first one, for t cyclic shift values there will be exactly A intersections and for the rest N — 1 — t cyclic shift values there will be exactly A + 1 intersections. If there are two (N, D,A,) NDSs and the second one is constructed as the cyclic shift of the first one, there will be exactly A intersections when the cyclic shift is 1, 2—N-l, except for (N / 2) mod N, there will be 0 intersection when the cyclic shift is (N / 2) mod N. The solutions allows to control cross-interference level while keeping self-interference at low level, and thus channelestimation performance can be ensured.

[0187] The solutions of the present disclosure may be applied in various communication scenarios in which channel estimation is performed based on reference signals. For example, the solutions of the present disclosure may be applied in a communication network operating in frequency division duplex (FDD) mode, or a communication network operating in time division duplex (TDD) mode.

[0188] In TDD mode, first the base station configures SRS resource, which is a part of general Radio Resource Control (RRC) Protocol. SRS resource contains information about the mapping of SRS signal on the resource grid (frequency-time, i.e. RE-Symbol). SRS resource also includes the information about antenna / port mapping for each SRS signal. The BS informs UE of the part of SRS resource configuration using Physical Downlink Control Channel (PDCCH). The UE receives information about SRS configuration, then configures and sends SRS to the base station in the uplink channel. The BS receives the SRS signals and performs channel estimation. Having estimated the channel, the base station sends the data to the UE and inserts Demodulation Reference Signals (DMRSs) to help UE demodulate the data and update the channel estimate. In this scenario, SRS is for uplink channel estimation, a DMRS is for downlink channel estimation. At least one of DS, ADS and NDS may be applied to resource allocation of SRS and / or DMRS.

[0189] In FDD mode, the channel estimation is performed in downlink channel using Channel State Information Reference Signal (CSI-RS). The BS configures CSI-RS and sends the configuration parameters to the UE in PDCCH. The UE estimates channel based on received CSI-RS, compresses it and sends it back to BS. In this scenario, at least one of DS, ADS and NDS may be applied to resource allocation of CSI-RS.

[0190] The proposed method is applicable to uplink SRS TDD MIMO OFDM channel estimation, and downlinkDMRS TDD MIMO OFDM channel estimation, which will be described in detail below.

[0191] The above briefly describes technical concepts of the present disclosure, and then specific embodiments of the present disclosure will be elaborated in the following description.

[0192] An embodiment of the present disclosure provides a wireless communication method, as shown in FIG. 14, the method includes: step 1402, transmitting a first reference signal using first REs associated with a first antenna port, where positions of the first REs are indicated by a first position sequence; step 1404, transmitting a second reference signal using second REs associated with a second antenna port, where positions of the second REs are indicated by a second position sequence; where the first position sequence and the second position sequence are obtained based on at least one target position set, each of the at least one target position set is a DS, an ADS or an NDS, and where the first antenna port is different from the second antenna port and the first position sequence is different from the second positionelement may be UE, and the second network element may be BS; or the first network element may be BS and the second network element may be UE. In a possible implementation, the first reference signal and the second reference signal are transmitted from BS to UE, or from UE to BS.

[0195] In a possible implementation of the present disclosure, both the first reference signal and the second reference signal are SRSs; or, both of the first reference signal and the second reference signal are DMRSs; or both of the first reference signal and the second reference signal are CSI-RSs.

[0196] In a possible implementation, REs occupied by a reference signal may be associated with an antenna port. The positions of REs occupied by a reference signal (i.e., first reference signal or second reference signal) may be indicated by aposition sequence (i.e., first position sequence or second position sequence). The positions of REs here refer to the positions of REs in frequency domain. The positions of REs occupied by a reference signal may also be referred to as the positions of subcarriers occupied by a reference signal. The position sequence includes multiple elements, and the value of each element may indicate the presence or absence of a reference signal. For example, a position sequence may include 11 elements: {0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0}, where element “1” may indicate the presence of reference signal, and element “0” may indicate absence of reference signal. Indices of these 11 elements may be denoted as: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 respectively, and then, elements with indices of 1, 3, 4, 5 and 9 have the value of 1, which indicates that REs with indices of 1, 3, 4, 5 and 9 have reference signals transmitted thereon. It should be noted that values such as 0 and 1 and a format of the elements used for describing the above elements are just illustrative, other values and formats may also be used for realizing the functions defined for these elements, and the specific values and formats are not limited in the embodiments of the present disclosure. Since the first position sequence for the first antenna port is different from the second position sequence for the second antenna port, complete overlapping between REs occupied by reference signals from different antenna ports can be avoided, which may enable reasonable resource allocation.

[0197] Moreover, the position sequences for different antenna ports are obtained based on at least one target position set, where each of the at least one target position set is a DS, an ADS or an NDS. That is, the DS, ADS or NDS as the target position set is used to obtain the position sequences for different antenna ports. Therefore, the amount of overlap between REs occupied by reference signals from different antenna ports can be precisely controlled, so that the cross-interference level between the antenna ports can be controlled and the transmission quality of the reference signals can be ensured, thereby improving channel estimation performance.

[0198] In a possible implementation of the present disclosure, the at least one target position set is determined from position information which includes multiple position sets, and each of the multiple position sets is a DS, an ADS or an NDS. The at least one target positions set may come from a DS / ADS / NDS group (which is a specific example of position information herein) which contains multiple DS / ADS / NDS. The target position set may be determined from multiple position sets, so that a suitable DS, ADS, or an NDS can be determined as the target position set to meet actual requirements or demands and adapt to different application scenarios.

[0199] In a possible implementation of the present disclosure, the position information may be pre-stored in a base station. In a possible implementation, the position information may be pre-stored in a user equipment, or obtained by the user equipment from a base station.

[0200] In a case where both the base station and the user equipment in communication have known the position information, the at least one target position set may be determined by the base station and the user equipment, respectively, according to a pre-defined rule. Or, each position set in the position information may have a unique identifier, such as a unique index, and the base station may determine the at least one target position set from the position information, and then inform the user equipment of the identifier of the at least one target position set.

[0201] In a case where the position information is simply pre-stored in the base station, while the user equipment does not have the position information, the at least one target position set may be determined by the base station andtransmission is 11, then a DS or ADS with parameter N closest to 11 among the multiple position sets may be determined as a target position set. A position sequence corresponding to the target position set may have a length of the first parameter. When a DS or ADS with parameter N of 11 is determined as the target position set, the position sequence corresponding to the target position set has the length of 11, and may be directly used to obtain the first and second position sequence to determine the positions of REs associated with the respective antenna ports. If parameter N is not equal to the total number of REs for reference signal transmission, other operations would need to be performed on the position sequence corresponding to the target position set. For example, an extension operation may be performed in a case where parameter N is less than the total number of the REs for reference signal transmission, so as to obtain an extended sequence with a length equal to the total number of the REs for reference signal transmission, or a shortening operation may be performed in a case where parameter N is greater than the total number of the REs for reference signal transmission, so as to obtain a shortened sequence with a length equal to the total number of the REs for reference signal transmission, which will be described in detail below.

[0208] Parameter D of the DS, ADS or NDS may be the second parameter of the target position set, which indicates the number of elements of the DS, ADS or NDS. The second parameter is related to the number of the REs occupied by the first reference signal or the second reference signal. The second parameter may also be considered in determining the taiget position set. Continuing to refer to the above example in which parameter N of the DS as 11, if there are more than one DS or ADS with parameter N of 11, then the number of the REs occupied by each reference signal may be further considered. For example, the number of the occupied REs is 5, and then a DS or ADS with parameter D closest to 5 is selected from the more than one DS / ADS with parameter N of 11 as the target position set. Parameter D may be the number of the elements in the DS or ADS, and the elements in the DS or ADS may be indices of elements in the position sequence corresponding to the DS / ADS that indicate presence of a reference signal. Assume that a DS with parameter N being 11 and parameter D being 5 is { 1, 3, 4, 5, 9}, then the position sequence corresponding to the DS can be determined as {0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0}, the elements 1, 3, 4, 5, and 9 of the DS are indices of elements in the position sequence and used to indicate presence of the reference signal.

[0209] Parameter A of the DS, ADS or NDS may be the third parameter of the target position set which indicates the number of repetition times of possible values of differences as mentioned above. The third parameter is related to a number of intersections between the REs on which the first reference signal is transmitted and the REs on which the second reference signal is transmitted. For example, when a DS with parameters ( 11,5,2) is determined as the target position set, the first position sequence corresponding to the first reference signal may be {0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0}, and the second position sequence corresponding to the second reference signal may be {0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1 }, and then there are two common elements between the first and second position sequence, i.e., the elements with indices of 4 and 5, and thus there are two common REs between the REs on which the first reference signal is transmitted and the REs on which the second reference signal is transmitted, i.e., the REs with indices of 4 and 5, which means, both the first and second reference signals are transmitted on the REs with indices of 4 and 5.

[0210] In a possible implementation of the present disclosure, the first position sequence and the second position sequence have at least one common element. In a possible implementation, the number of common elements may be related to or indicated by the third parameter of the target position set. Continuing to refer to the above example where parameter A (i.e., third parameter) is 2, the first position sequence is {0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0} and the second position sequence is{0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1 }, there are 2 common elements between the first position sequence and the second position sequence, namely the element with index of 4 and the element with index of 5 for both position sequences.

[0211] Since the first position sequence and the second position sequence are obtained based on at least one target position set, and each target position set is a DS, ADS or NDS, the first position sequence and the secondfor reference signal transmission. The first parameter may be parameter N for DS, ADS or NDS as described above. When determining the first target position set from the position information, the first parameter of position set may be considered, so that the first target position set as determined is suitable for the total number of REs, thereby ensuring reasonable allocation of REs.

[0220] In a possible implementation of the present disclosure, the first target position set is a position set with a first parameter closest to the total number of the REs for reference signal transmission among the multiple position sets. A position set with a first parameter closest to the total number of REs for reference signal transmission may be determined as the first target position set, so that a position sequence corresponding to the determined position set may have a length closest to the total number of REs for reference signal transmission, which can ensure the control over the common REs and reduce operations, such as extension or shortening, which may be performed to make the length of a position sequence match with the total number of REs.

[0221] In a possible implementation of the present disclosure, in a case that the position information includes more than one position set with the first parameter closest to the total number of the REs for reference signal transmission, the first target position set is determined from the more than one position set based on a second parameter of the first target position set and a number of REs occupied by the first reference signal or the second reference signal. The second parameter may be parameter D for DS, ADS or NDS as described above. Among the multiple position sets included in the position information, there may be two or more position sets having the same value of the first parameter. Therefore, when determining the first target position set, there may exist more than one position set with the first parameter closest to the total number of REs for reference signal transmission. In this case, the second parameter for DS, ADS or NDS may be further considered, so that the first target position set, which is determined from the more than one position set with the closest first parameter, is suitable for the number of REs occupied by a reference signal. Since the first target position set is determined based on the first parameter and the total number of REs for reference signal transmission, as well as the second parameter and the number of REs occupied by a reference signal, a more suitable target position set can be determined, thereby realizing reasonable allocation of REs.

[0222] In a possible implementation of the present disclosure, the first target position set is a position set with a second parameter closest to the number of the REs occupied by the first reference signal or the second reference signal. From more than one position set with the closest first parameter, a position set with a second parameter closest to the number of REs occupied by a reference signal may be determined as the first target position set, so that the number of elements included in the first target position set may be closest to the number of REs occupied by a reference signal.

[0223] In a possible implementation, the position information may be represented as a table. An example of DS table is shown in Table 1 below.Table 1

[0224] As shown in Table 1, each DS has its corresponding first parameter N, second parameter D and third parameter A. A specific example of determining the first target position set may be as follows. First, the total number of RBs for reference signal transmission is determined. For example, the total RBs number is 12. Then the total number of REs for reference signal transmission is determined based on the total number of RBs. Since each RB contains 12 REs, the chosen total number of subcarriers (or the total number of REs) for resource allocation is 12 • 12 = 144. Next, search Table 1 for a DS with a value N closest to 144. From Table 1, the closet value is N=143, and a corresponding DS with parameters (143, 71, 35) is chosen, and thus the DS with parameters (143, 71, 35) is determined as the first target position set.

[0225] In a possible implementation of the present disclosure, the DS table may provide too little options for different values of N, D, A. In addition to the DS table, or alternatively, an ADS table may be provided, for example, as shown in Table 2 below. Table 2 simply shows the first parameter N, second parameter D, the third parameter A and the fourth parameter t of ADS, without showing specific elements of each ADS.Table 2

[0226] The ADS table can provide much more options for different values of N, D, X. The determination of the first target position set from the ADS table is similar to that of DS table.

[0227] Since the ADS table provides much more options, there may be more than one position set selected from table 2 or from table 1 and table 2 based on the first parameter N. In such a case, the second parameter D may befurther considered.

[0228] In a possible implementation of the present disclosure, in addition to the DS table and ADS table, or alternatively, an NDS table may be provided, for example, as shown in Table 3 below. Table 3 shows the first parameter N, the second parameter D, the third parameter X and specific elements of each NDS.Table 3

[0229] Among them, the first parameter is an even integer and larger than or equal to 4, and the determination of the first target position set from the NDS table is similar to that of DS table and ADS table.

[0230] In a possible implementation, when there is more than one position set (which is also referred to as first candidate position set below) with the closest value N is determined, the number of REs occupied by each reference signal is determined, and then a position set with a second parameter D closest to the number of REs occupied by each reference signal is determined from the more than one first candidate position set, and regarded as the first target position set when it is unique.

[0231] In a possible implementation, when there is more than one position set (which is also referred to as second candidate position set below) with the closest value N and the closest value D, any of the more than one second candidate position set may be taken as the first target position set, or the first target position set may be determined from the more than one second candidate position set according to a pre-defined rule. For example, the third parameter X may be further considered, and a second candidate difference set with the smallest third parameter A may be selected as the first target position set to reduce the overlap between different reference signals from different antenna ports. The determination of the first target position set from more than one second candidate position set may be performed in various ways according to actual needs, which are not limited in the embodiments of the present disclosure.

[0232] In a possible implementation of the present disclosure, the first position sequence is obtained based on a position sequence and the first cyclic shift, and the second position sequence is obtained based on the position sequence and the second cyclic shift, where the position sequence is obtained based on the first target position set, the position sequence has a length equal to the first parameter of the first target position set, and elements of the position sequence with indices equal to elements of the first target position set have a value indicating presence of a reference signal.

[0233] In a possible implementation, after determining the first target position set, the position sequence corresponding to the first target position set can be obtained. For example, if the determined first target position set is the DS with parameters (143, 71, 35), i.e., the last entry in Table 1 which is {0, 1, 2, 3, 4, 6, 7, 8, 9, 12, 13, 14, 16, 18, 19, 21, 23, 24, 25, 26, 27, 28, 32, 36, 38, 39, 41, 42, 46, 48, 49, 50, 52, 53, 54, 56, 57, 63, 64, 65, 69, 72, 73, 75, 76, 78, 81, 82, 83, 84, 85, 91, 92, 96, 98,100,103,104,106,108,109,112,113,114,117,123,126,128,130,133,138}, then the corresponding position sequence has a length of 143, and 71 elements of the position sequence with indices equal to 0, 1, 2, 3, 4, 30,133,138 have a value indicating presence of a reference signal. Next, cyclic shifts csx, cs2, cs3, ... CSNTXfor every TX antennas / antenna ports are used, and cyclic shifts can vary from 0 to 142.

[0234] A position sequence corresponding to the first target position set can be obtained based on the first targetcould be obtained in the followings: a position sequence corresponding to the first antenna port may be obtained based on the NDS {0, 1, 2, 5, 10}, where the position sequence is { 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0}, and indices of elements in this sequence are from 0 to 11 , which is not limited in the embodiments of the present disclosure; position sequences corresponding to the rest 11 antenna ports may be obtained based on the NDS and cyclic shift values 1, 2 , .. 11, respectively. In FIG. 17, the white area indicates the position of REs occupied by the reference signal. The NDS has parameters 2 = 2, for antenna port 1, each of the rest 11 antenna has two common REs with antenna 1, except for antenna 7; that is, the position sequence with cyclic shift of 0 corresponding to antenna port 1 and the position sequence with cyclic shift of (12 / 2)mod(12)=6 corresponding to antenna port 7 have no common RE. Similarly, for antenna port 2, each of the rest 11 antenna has two common REs with antenna port 2, except for antenna 8. Thus, the number of intersections is controlled, and thus the cross-interference level is known and can also be controlled.

[0243] The above embodiments are mainly implemented based on one DS, ADS or NDS (i.e., the first target position set) for multiple antenna ports. The first position sequence corresponding to the first antenna port is based on the first target position set and the first cyclic shift, and the second position sequence corresponding to the second antenna port is based on the first target position set and the second cyclic shift different from the first cyclic shift, and the second position sequence can be thought as the cyclic shift of the first position sequence, and they will have exactly A intersections, or have 0 intersection. In the case where the first target position set is an ADS and there are N antenna ports, for each antenna port, there will be exactly t antenna ports with A common REs and there will be rest N — 1 — t antenna ports with A + 1 common REs.

[0244] In the following, the resource allocation for reference signal using the DS / ADS / NDS in combination with a comb-like structure will be described in detail below. The pilot position sequence can be applied to comb-like structures. For example, given a sequence s = [s1(s2, ... sN], it can be mapped to subcarriers 1, 1 + comb, 1 + 2 • comb , ... and so on, leaving the other subcarriers empty.

[0245] In a possible implementation of the present disclosure, positions of the first REs are indicated by the first position sequence and a first comb value; and positions of the second REs are indicated by the second position sequence and a second comb value. In a possible implementation, the first comb value and the second comb value correspond to the first antenna port and the second antenna port respectively, and may be pre-stored in the base station, indicated from the base station to the user equipment, or pre-stored in both the user equipment and the base station, which is not limited in the embodiments of the present disclosure.

[0246] The REs indicated by the first and second position sequences can be mapped with a comb-like structure, that is, the resource allocation can be implemented by applying the DS / ADS / NDS in combination with the comblike structure. Thus, the number of common REs between REs occupied by reference signals from the first and second antenna ports can be precisely controlled and thus the cross-interference level between the antenna ports can be controlled, and meanwhile overhead for channel estimation can be reduced.

[0247] In a possible implementation of the present disclosure, the first comb value is equal to the second comb value. The at least one target position set may include a first target position set and / or a second target position set, where the at least one target position set is determined based on a first parameter of the at least one target position set, a total number of REs for reference signal transmission and the first comb value or the second comb value.

[0248] In a possible implementation, the first target position set is a position set with a first parameter closest to a quotient between a total number of REs for reference signal transmission and the first comb value, and the second target position set is a position set with a first parameter closest to a quotient between the total number of REs for reference signal transmission and the second comb value. Since the first comb value is equal to the second comb value, the first target position set may be the same as the second target position set. For example, the first antenna port and the second antenna port may correspond to the same comb value comb and the same comb offset offs, whichtarget position sets and respective cyclic shifts, so as to control the cross-interference level between the antenna ports and ensure the transmission quality of the reference signals.

[0269] In a possible implementation, the solutions described above may be applied to uplink channel estimation in TOD MIMO OFDM systems. For example, the solutions described above may be applied to uplink SRS TOD MIMO OFDM channel estimation. The allocation of SRS reference signals can be determined using the solutions provided above. To perform channel estimation, the BS may choose DS / ADS / NDS from the table (Table 1 and / or Table 2) and determine cyclic shifts for eveiy UE antenna ports. After that the BS may send this information to the UE via the control channel. The UE may use a predefined table to determine the used DS / ADS / NDS and further use the received cyclic shift values to determine the sampling pattern for every antenna port. Using this configuration, UE sends SRS signals in the uplink channel to the Base Station.

[0270] In a possible implementation, the solutions described above may be applied to downlink DMRS TDD MIMO OFDM channel estimation. The BS can determine the DS / ADS / NDS from the predefined table and determine cyclic shifts for each BS antenna port. After that, the BS can use this information to configure DMRS in the downlink channel. BS may also send the information of the chosen DS / ADS / NDS and the cyclic shifts to the UE. Based on this information, the UE reconstructs the DMRS configuration and uses the received DMRS to estimate the effective channel.

[0271] In the solutions of the present disclosure, positions of REs occupied by a reference signal may be indicated by a position sequence. Position sequences are different for different antenna ports, and thus complete overlapping between REs occupied by reference signals from different antenna ports can be avoided, which may enable reasonable resource allocation. In addition, at least one of the difference set, the almost difference set and the near difference set is used to obtain the position sequences for different antenna ports, and thus, the amount of overlap between REs occupied by reference signals from different antenna ports can be precisely controlled, so that the crossinterference level between the antenna ports can be controlled and the transmission quality of the reference signals can be ensured, thereby improving channel estimation performance.

[0272] FIG. 20 shows a schematic flowchart of another wireless communication method according to one or more embodiments of the present disclosure. The method also can be implemented by the first network element or the second network element as described above. As shown in FIG. 20, the method may include: step 2002, receiving, a first reference signal using first REs associated with a first antenna port, where positions of the first REs are indicated by a first position sequence; step 2004, receiving a second reference signal using second REs associated with a second antenna port, where positions of the second REs are indicated by a second position sequence; where the first position sequence and the second position sequence are obtained based on at least one taiget position set, each of the at least one target position set is a difference set, an almost difference set or a near difference set, and where the first antenna port is different from the second antenna port and the first position sequence is different from the second position sequence.

[0273] It should be noted that in a case where the first network element or the second network element is implemented as a module, the receiving operation may also be an inputting operation, it is not necessary to receive but just to input the reference signal from a certain device with a receiving function, the specific details with regard to the receiving operation performed by the first network element or the second network element throughout the document also apply for the inputting operation.

[0274] For the above step, reference may be made to the forgoing relevant description of the method shown in FIG. 14, which will not be repeated here.

[0275] In a possible implementation of the present disclosure, the first position sequence and the second position sequence have at least one common element.

[0276] In a possible implementation of the present disclosure, the first position sequence and the second position sequence are obtained based on the at least one target position set with a first cyclic shift and a second cyclic shift, respectively, where the first cyclic shift corresponds to the first antenna port, the second cyclic shift corresponds to the second antenna port, and the first cyclic shift is different from the second cyclic shift.

[0277] In a possible implementation of the present disclosure, the at least one target position set is determined from position information which includes multiple position sets, and each of the multiple position sets is a difference set, an almost difference set, or a near difference set.

[0278] In a possible implementation of the present disclosure, the at least one target position set includes a first target position set, and each of the multiple position sets has a first parameter, where the first target position set is determined from the position information based on the first parameter of the first target position set and a total number of REs for reference signal transmission.

[0279] In a possible implementation of the present disclosure, the first target position set is a position set with a first parameter closest to the total number of the REs for reference signal transmission among the multiple position sets.

[0280] In a possible implementation of the present disclosure, in a case that the position information includes more than one position set with the first parameter closest to the total number of the REs for reference signal transmission, the first target position set is determined from the more than one position set based on a second parameter of the first target position set and a number of REs occupied by the first reference signal or the second reference signal.

[0281] In a possible implementation of the present disclosure, the first target position set is a position set with a second parameter closest to the number of the REs occupied by the first reference signal or the second reference signal.

[0282] In a possible implementation of the present disclosure, the first position sequence is obtained based on a position sequence and the first cyclic shift, and the second position sequence is obtained based on the position sequence and the second cyclic shift, where the position sequence is obtained based on the first target position set, the position sequence has a length equal to the first parameter of the first target position set, and elements of the position sequence with indices equal to elements of the first target position set have a value indicating presence of a reference signal.

[0283] In a possible implementation of the present disclosure, in a case that at least one first condition is satisfied, where the at least one first condition includes the first parameter of the first target position set is greater than the total number of the REs for reference signal transmission, the first position sequence is obtained based on a shortened position sequence and the first cyclic shift, and the second position sequence is obtained based on the shortened position sequence and the second cyclic shift, where the shortened position sequence includes part of elements of the position sequence, and the shortened position sequence has a length equal to the total number of the REs for reference signal transmission.

[0284] In a possible implementation of the present disclosure, in a case that at least one second condition is satisfied, where the at least one second condition includes the first parameter of the first target position set is less than the total number of the REs for reference signal transmission, the first position sequence is obtained based on an extended position sequence and the first cyclic shift, and the second position sequence is obtained based on the extended position sequence and the second cyclic shift, where the extended position sequence includes the elements of the position sequence with part of the elements of the position sequence being repeated, and the extended position sequence has a length equal to the total number of the REs for reference signal transmission.

[0285] In a possible implementation of the present disclosure, positions of the first REs are indicated by the first position sequence and a first comb value; and positions of the second REs are indicated by the second positionsequence and a second comb value.

[0286] In a possible implementation of the present disclosure, the first comb value is equal to the second comb value, the at least one target position set includes a first target position set and / or a second target position set, where the at least one target position set is determined based on a first parameter of the one target position set, a total number of REs for reference signal transmission and the first comb value or the second comb value.

[0287] In a possible implementation of the present disclosure, the first comb value is greater than the second comb value, and the first comb value is an integer multiple of the second comb value; where the at least one target position set includes a first target position set and a second target position set, where the first target position set is determined based on a first parameter of the first target position set, a total number of REs for reference signal transmission and the first comb value, and the second target position set is determined based on a first parameter of the second target position set, the total number of the REs for reference signal transmission, the first comb value and the second comb value; where the first position sequence is obtained based on the first target position set and a third cyclic shift, and the second position sequence is obtained based on the first target position set, a fourth cyclic shift different from the third cyclic shift, and the second target position set.

[0288] In a possible implementation of the present disclosure, each of the at least one target position set has a third parameter, and the third parameter is related to a number of intersections between the REs on which the first reference signal is transmitted and the REs on which the second reference signal is transmitted.|0289] In a possible implementation of the present disclosure, the at least one target position set is determined by a base station and a user equipment, respectively, according to a pre-defined rule, or the at least one target position set is determined by a base station and indicated from the base station to a user equipment.

[0290] In a possible implementation of the present disclosure, the first cyclic shift and the second cyclic shift are indicated from a base station to a user equipment.

[0291] Next, embodiments of products related to the wireless communication methods will be described.

[0292] FIG. 21 shows a schematic structural diagram of a wireless communication apparatus according to one or more embodiments of the present disclosure. As shown in FIG. 21, the wireless communication apparatus 2100 may include: a first transmitting module 2102, configured to transmit a first reference signal using first resource elements (REs) associated with a first antenna port, where positions of the first REs are indicated by a first position sequence; a second transmitting module 2104, configured to transmit a second reference signal using second REs associated with a second antenna port, where positions of the second REs are indicated by a second position sequence; where the first position sequence and the second position sequence are obtained based on at least one target position set, each of the at least one target position set is a difference set, an almost difference set or a near difference set, and where the first antenna port is different from the second antenna port and the first position sequence is different from the second position sequence.

[0293] In a possible implementation of the present disclosure, the first position sequence and the second position sequence have at least one common element.

[0294] In a possible implementation of the present disclosure, the first position sequence and the second position sequence are obtained based on the at least one target position set with a first cyclic shift and a second cyclic shift, respectively, where the first cyclic shift corresponds to the first antenna port, the second cyclic shift corresponds to the second antenna port, and the first cyclic shift is different from the second cyclic shift.

[0295] In a possible implementation of the present disclosure, the at least one target position set is determined from position information which includes multiple position sets, and each of the multiple position sets is a differencecomb value, and the first comb value is an integer multiple of the second comb value; where the at least one target position set includes a first target position set and a second target position set, where the first target position set is determined based on a first parameter of the first target position set, a total number of REs for reference signal transmission and the first comb value, and the second target position set is determined based on a first parameter of the second target position set, the total number of the REs for reference signal transmission, the first comb value and the second comb value; where the first position sequence is obtained based on the first target position set and a third cyclic shift, and the second position sequence is obtained based on the first target position set, a fourth cyclic shift different from the third cyclic shift, and the second target position set.

[0306] In a possible implementation of the present disclosure, each of the at least one target position set has a third parameter, and the third parameter is related to a number of intersections between the REs on which the first reference signal is transmitted and the REs on which the second reference signal is transmitted.

[0307] In a possible implementation of the present disclosure, the at least one target position set is determined by a base station and a user equipment, respectively, according to a pre-defined rule, or the at least one target position set is determined by a base station and indicated from the base station to a user equipment.

[0308] In a possible implementation of the present disclosure, the first cyclic shift and the second cyclic shift are indicated from a base station to a user equipment.

[0309] It should be noted that, the first transmitting module and the second transmitting module are only illustrative for their functions, in practice, the functions of the first transmitting module and the second transmitting module may be implemented by one transmitting module, which is not limited here. It should also be noted that, the functions of the transmitting modules and the receiving module may also be implemented by a transceiving module.

[0310] The wireless communication apparatus may be applied to the first network element or the second network element as described in the above method embodiments or may be the first network element or the second network element as described in the above method embodiments. It should be understood by a person skilled in the art that, the relevant description of the above modules in the embodiments of the present disclosure may be understood with reference to the relevant description of the wireless communication method in the embodiments of the present disclosure.

[0311] FIG. 22 shows a schematic structural diagram of another wireless communication apparatus according to one or more embodiments of the present disclosure. As shown in FIG. 22, the wireless communication apparatus 2200 may include: a first receiving module 2202, configured to receive a first reference signal using first resource elements (REs) associated with a first antenna port, where positions of the first REs are indicated by a first position sequence; a second receiving module 2204, configured to receive a second reference signal using second REs associated with a second antenna port, where positions of the second REs are indicated by a second position sequence; where the first position sequence and the second position sequence are obtained based on at least one target position set, each of the at least one target position set is a difference set, an almost difference set or a near difference set, and where the first antenna port is different from the second antenna port and the first position sequence is different from the second position sequence.

[0312] In a possible implementation of the present disclosure, the first position sequence and the second position sequence have at least one common element.

[0313] In a possible implementation of the present disclosure, the first position sequence and the second position sequence are obtained based on the at least one target position set with a first cyclic shift and a second cyclic shift, respectively, where the first cyclic shift corresponds to the first antenna port, the second cyclic shift corresponds to the second antenna port, and the first cyclic shift is different from the second cyclic shift.

[0314] In a possible implementation of the present disclosure, the at least one target position set is determined from position information which includes multiple position sets, and each of the multiple position sets is a difference set, an almost difference set, or a near difference set.

[0315] In a possible implementation of the present disclosure, the at least one target position set includes a first target position set, and each of the multiple position sets has a first parameter, where the first target position set is determined from the position information based on the first parameter of the first target position set and a total number of REs for reference signal transmission.

[0316] In a possible implementation of the present disclosure, the first target position set is a position set with a first parameter closest to the total number of the REs for reference signal transmission among the multiple position sets.

[0317] In a possible implementation of the present disclosure, in a case that the position information includes more than one position set with the first parameter closest to the total number of the REs for reference signal transmission, the first target position set is determined from the more than one position set based on a second parameter of the first target position set and a number of REs occupied by the first reference signal or the second reference signal.

[0318] In a possible implementation of the present disclosure, the first target position set is a position set with a second parameter closest to the number of the REs occupied by the first reference signal or the second reference signal.

[0319] In a possible implementation of the present disclosure, the first position sequence is obtained based on a position sequence and the first cyclic shift, and the second position sequence is obtained based on the position sequence and the second cyclic shift, where the position sequence is obtained based on the first target position set, the position sequence has a length equal to the first parameter of the first target position set, and elements of the position sequence with indices equal to elements of the first target position set have a value indicating presence of a reference signal.

[0320] In a possible implementation of the present disclosure, in a case that at least one first condition is satisfied, where the at least one first condition includes the first parameter of the first target position set is greater than the total number of the REs for reference signal transmission, the first position sequence is obtained based on a shortened position sequence and the first cyclic shift, and the second position sequence is obtained based on the shortened position sequence and the second cyclic shift, where the shortened position sequence includes part of elements of the position sequence, and the shortened position sequence has a length equal to the total number of the REs for reference signal transmission.

[0321] In a possible implementation of the present disclosure, in a case that at least one second condition is satisfied, where the at least one second condition includes the first parameter of the first target position set is less than the total number of the REs for reference signal transmission, the first position sequence is obtained based on an extended position sequence and the first cyclic shift, and the second position sequence is obtained based on the extended position sequence and the second cyclic shift, where the extended position sequence includes the elements of the position sequence with part of the elements of the position sequence being repeated, and the extended position sequence has a length equal to the total number of the REs for reference signal transmission.

[0322] In a possible implementation of the present disclosure, positions of the first REs are indicated by the first position sequence and a first comb value; and positions of the second REs are indicated by the second position sequence and a second comb value.

[0323] In a possible implementation of the present disclosure, the first comb value is equal to the second comb value, the at least one target position set includes a first target position set and / or a second target position set, where the at least one target position set is determined based on a first parameter of the one target position set, a totalnumber of REs for reference signal transmission and the first comb value or the second comb value.

[0324] In a possible implementation of the present disclosure, the first comb value is greater than the second comb value, and the first comb value is an integer multiple of the second comb value; where the at least one target position set includes a first target position set and a second target position set, where the first target position set is determined based on a first parameter of the first target position set, a total number of REs for reference signal transmission and the first comb value, and the second target position set is determined based on a first parameter of the second target position set, the total number of the REs for reference signal transmission, the first comb value and the second comb value; where the first position sequence is obtained based on the first target position set and a third cyclic shift, and the second position sequence is obtained based on the first target position set, a fourth cyclic shift different from the third cyclic shift, and the second target position set.

[0325] In a possible implementation of the present disclosure, each of the at least one target position set has a third parameter, and the third parameter is related to a number of intersections between the REs on which the first reference signal is transmitted and the REs on which the second reference signal is transmitted.

[0326] In a possible implementation of the present disclosure, the at least one target position set is determined by a base station and a user equipment, respectively, according to a pre-defined rule, or the at least one target position set is determined by a base station and indicated from the base station to a user equipment.

[0327] In a possible implementation of the present disclosure, the first cyclic shift and the second cyclic shift are indicated from a base station to a user equipment.

[0328] It should be noted that, the first receiving module and the second receiving module are only illustrative for their functions, in practice, the functions of the first receiving module and the second receiving module may be implemented by one receiving module, which is not limited here. It should also be noted that, the functions of the transmitting modules and the receiving module may also be implemented by a transceiving module.

[0329] The wireless communication apparatus may be applied to the first network element or the second network element as described in the above method embodiments or may be the first network element or the second network element as described in the above method embodiments. It should be understood by a person skilled in the art that, the relevant description of the above modules in the embodiments of the present disclosure may be understood with reference to the relevant description of the wireless communication method in the embodiments of the present disclosure.

[0330] FIG. 23 is a schematic structural diagram of a wireless communication apparatus according to one or more embodiments of the present disclosure, the apparatus may be a second network element or a first network element. As shown in FIG. 23, the wireless communication apparatus 2300 includes a processor 2302, an interface 2304 for communicating with other devices, and a memory 2306. The memory 2306 may be stored with computer execution instructions, and the processor 2302 executes computer execution instructions stored in the memory 2306 to enable the apparatus to execute any of the above wireless communication methods.

[0331] In some aspects of the present disclosure, there is provided a first network element including processing circuitry for executing any of the above wireless communication methods. It should be understood that the first network element can execute the steps performed by the first network element in the above method embodiments, which will not be repeated here.|0332] In some aspects of the present disclosure, there is provided a second network element including processing circuitry for executing any of the above wireless communication methods. It should be understood that the second network element can execute the steps performed by the second network element in the above method embodiments, which will not be repeated here.

[0333] In some aspects of the present disclosure, there is provided a wireless communication apparatus whichincludes a processor and a memory. The memory is storing instructions that cause the processor to perform any of the above wireless communication methods.

[0334] In some aspects of the present disclosure, there is provided a wireless communication system, including a second network element and a first network element. The second network element is configured to execute the steps executed by the second network element in any of the above wireless communication methods, and the first network element is configured to execute the steps executed by the first network element in any of the above wireless communication methods.

[0335] In some aspects of the present disclosure, there is provided a chip, including an input / output (I / O) interface and a processor, where the processor is configured to call and run computer execution instructions stored in a memory, to enable a device installing with the chip to execute any of the above wireless communication methods.

[0336] In some aspects of the present disclosure, there is provided a computer-readable medium storing computer execution instructions which, when executed by a processor, causes the processor to execute any of the above wireless communication methods.

[0337] In some aspects of the present disclosure, there is provided a computer program product including computer execution instructions which, when executed by a processor, causes the processor to execute any of the above wireless communication methods.

[0338] In some aspects of the present disclosure, there is provided a computer program including computer execution instructions which, when executed by a processor, cause the processor to execute any of the above wireless communication methods.

[0339] Although the present disclosure describes methods and processes with steps in a certain order, one or more steps of the methods and processes may be omitted or altered as appropriate. One or more steps may take place in an order other than that in which they are described, as appropriate.

[0340] Note that the expression “at least one of A or B”, as used herein, is interchangeable with the expression “A and / or B”. It refers to a list in which you may select A or B or both A and B. Similarly, “at least one of A, B, or C”, as used herein, is interchangeable with “A and / or B and / or C” or “A, B, and / or C”. It refers to a list in which you may select: A or B or C, or both A and B, or both A and C, or both B and C, or all of A, B and C. The same principle applies for longer lists having a same format.

[0341] Although the present disclosure is described, at least in part, in terms of methods, a person of ordinary skill in the art will understand that the present disclosure is also directed to the various components for performing at least some of the aspects and features of the described methods, be it by way of hardware components, software or any combination of the two. Accordingly, the technical solution of the present disclosure may be embodied in the form of a software product. A suitable software product may be stored in a pre-recorded storage device or other similar non-volatile or non-transitory computer readable medium, including DVDs, CD-ROMs, USB flash disk, a removable hard disk, or other storage media, for example. The software product includes instructions tangibly stored thereon that enable a processing device (e.g., a personal computer, a server, or a network device) to execute examples of the methods disclosed herein. The machine-executable instructions may be in the form of code sequences, configuration information, or other data, which, when executed, cause a machine (e.g., a processor or other processing device) to perform steps in a method according to examples of the present disclosure.

[0342] The present disclosure may be embodied in other specific forms without departing from the subject matter of the claims. The described example embodiments are to be considered in all respects as being only illustrative and not restrictive. Selected features from one or more of the above-described embodiments may be combined to create alternative embodiments not explicitly described, features suitable for such combinations being understood within the scope of this disclosure.

[0343] All values and sub-ranges within disclosed ranges are also disclosed. Also, although the systems, devicesand processes disclosed and shown herein may include a specific number of elements / components, the systems, devices and assemblies could be modified to include additional or fewer of such elements / components. For example, although any of the elements / components disclosed may be referenced as being singular, the embodiments disclosed herein could be modified to include a plurality of such elements / components. The subject matter described herein intends to cover and embrace all suitable changes in technology.

[0344] Although embodiments have been described above with reference to the accompanying drawings, those of skill in the art will appreciate that variations and modifications may be made without departing from the scope thereof as defined by the appended claims.

Claims

CLAIMS1. A wireless communication method, comprising: transmitting a first reference signal using first resource elements (REs) associated with a first antenna port, wherein positions of the first REs are indicated by a first position sequence; transmitting a second reference signal using second REs associated with a second antenna port, wherein positions of the second REs are indicated by a second position sequence; wherein the first position sequence and the second position sequence are obtained based on at least one target position set, each of the at least one taiget position set is a difference set, an almost difference set or a near difference set, and wherein the first antenna port is different from the second antenna port and the first position sequence is different from the second position sequence.

2. The method according to claim 1, wherein the first position sequence and the second position sequence have at least one common element.

3. The method according to claim 1, wherein the first position sequence and the second position sequence are obtained based on the at least one target position set with a first cyclic shift and a second cyclic shift, respectively, wherein the first cyclic shift corresponds to the first antenna port, the second cyclic shift corresponds to the second antenna port, and the first cyclic shift is different from the second cyclic shift.

4. The method according to claim 3, wherein the at least one target position set is determined from position information which comprises multiple position sets, and each of the multiple position sets is a difference set, an almost difference set, or a near difference set.

5. The method according to claim 4, wherein the at least one target position set comprises a first target position set, and each of the multiple position sets has a first parameter, wherein the first target position set is determined from the position information based on the first parameter of the first target position set and a total number of REs for reference signal transmission.

6. The method according to claim 5, wherein the first taiget position set is a position set with a first parameter closest to the total number of the REs for reference signal transmission among the multiple position sets.

7. The method according to claim 6, wherein in a case that the position information comprises more than one position set with the first parameter closest to the total number of the REs for reference signal transmission, the first target position set is determined from the more than one position set based on a second parameter of the first target position set and a number of REs occupied by the first reference signal or the second reference signal.

8. The method according to claim 7, wherein the first target position set is a position set with a second parameter closest to the number of the REs occupied by the first reference signal or the second reference signal.

9. The method according to any one of claims 6 to 8, wherein the first position sequence is obtained based on a position sequence and the first cyclic shift, and the second position sequence is obtained based on the position sequence and the second cyclic shift, wherein the position sequence is obtained based on the first target position set, the position sequence has a length equal to the first parameter of the first target position set, and elements of the position sequence with indices equal to elements of the first target position set have a value indicating presence of a reference signal.

10. The method according to claim 9, wherein in a case that at least one first condition is satisfied, wherein the at least one first condition comprises the first parameter of the first target position set is greater than the total number of the REs for reference signal transmission, the first position sequence is obtained based on a shortened position sequence and the first cyclic shift, and the second position sequence is obtained based on the shortened position sequence and the second cyclic shift, wherein the shortened position sequence comprises part of elements of theposition sequence, and the shortened position sequence has a length equal to the total number of the REs for reference signal transmission.

11. The method according to claim 9 or 10, wherein in a case that at least one second condition is satisfied, wherein the at least one second condition comprises the first parameter of the first target position set is less than the total number of the REs for reference signal transmission, the first position sequence is obtained based on an extended position sequence and the first cyclic shift, and the second position sequence is obtained based on the extended position sequence and the second cyclic shift, wherein the extended position sequence comprises the elements of the position sequence with part of the elements of the position sequence being repeated, and the extended position sequence has a length equal to the total number of the REs for reference signal transmission.

12. The method according to any one of claims 1 to 4, wherein positions of the first REs are indicated by the first position sequence and a first comb value; and positions of the second REs are indicated by the second position sequence and a second comb value.

13. The method according to claim 12, wherein the first comb value is equal to the second comb value, the at least one target position set comprises a first target position set and / or a second target position set, wherein the at least one target position set is determined based on a first parameter of the at least one target position set, a total number of REs for reference signal transmission and the first comb value or the second comb value.

14. The method according to claim 12, wherein the first comb value is greater than the second comb value, and the first comb value is an integer multiple of the second comb value; wherein the at least one target position set comprises a first target position set and a second target position set, wherein the first target position set is determined based on a first parameter of the first target position set, a total number of REs for reference signal transmission and the first comb value, and the second taiget position set is determined based on a first parameter of the second target position set, the total number of the REs for reference signal transmission, the first comb value and the second comb value; wherein the first position sequence is obtained based on the first target position set and a third cyclic shift, and the second position sequence is obtained based on the first target position set, a fourth cyclic shift different from the third cyclic shift, and the second target position set.

15. The method according to any one of claims 5 to 14, wherein each of the at least one target position set has a third parameter, and the third parameter is related to a number of intersections between the REs on which the first reference signal is transmitted and the REs on which the second reference signal is transmitted.

16. The method according to any one of claims 1 to 15, wherein the at least one target position set is determined by a base station and a user equipment, respectively, according to a pre-defined rule, or the at least one target position set is determined by a base station and indicated from the base station to a user equipment.

17. The method according to any one of claims 3 to 16, wherein the first cyclic shift and the second cyclic shift are indicated from a base station to a user equipment.

18. A wireless communication method, comprising: receiving a first reference signal using first resource elements (REs) associated with a first antenna port, wherein positions of the first REs are indicated by a first position sequence; receiving a second reference signal using second REs associated with a second antenna port, wherein positions of the second REs are indicated by a second position sequence; wherein the first position sequence and the second position sequence are obtained based on at least one target position set, each of the at least one target position set is a difference set, an almost difference set or a near difference set, and wherein the first antenna port is different from the second antenna port and the first position sequence isdifferent from the second position sequence.

19. The method according to claim 18, wherein the first position sequence and the second position sequence have at least one common element.

20. The method according to claim 18, wherein the first position sequence and the second position sequence are obtained based on the at least one target position set with a first cyclic shift and a second cyclic shift, respectively, wherein the first cyclic shift corresponds to the first antenna port, the second cyclic shift corresponds to the second antenna port, and the first cyclic shift is different from the second cyclic shift.

21. The method according to claim 20, wherein the at least one target position set is determined from position information which comprises multiple position sets, and each of the multiple position sets is a difference set, an almost difference set, or a near difference set.

22. The method according to claim 21 , wherein the at least one target position set comprises a first target position set, and each of the multiple position sets has a first parameter, wherein the first target position set is determined from the position information based on the first parameter of the first target position set and a total number of REs for reference signal transmission.

23. The method according to claim 22, wherein the first target position set is a position set with a first parameter closest to the total number of the REs for reference signal transmission among the multiple position sets.

24. The method according to claim 23, wherein in a case that the position information comprises more than one position set with the first parameter closest to the total number of the REs for reference signal transmission, the first target position set is determined from the more than one position set based on a second parameter of the first target position set and a number of REs occupied by the first reference signal or the second reference signal.

25. The method according to claim 24, wherein the first target position set is a position set with a second parameter closest to the number of the REs occupied by the first reference signal or the second reference signal.

26. The method according to any one of claims 23 to 25, wherein the first position sequence is obtained based on a position sequence and the first cyclic shift, and the second position sequence is obtained based on the position sequence and the second cyclic shift, wherein the position sequence is obtained based on the first target position set, the position sequence has a length equal to the first parameter of the first target position set, and elements of the position sequence with indices equal to elements of the first target position set have a value indicating presence of a reference signal.

27. The method according to claim 26, wherein in a case that at least one first condition is satisfied, wherein the at least one first condition comprises the first parameter of the first target position set is greater than the total number of the REs for reference signal transmission, the first position sequence is obtained based on a shortened position sequence and the first cyclic shift, and the second position sequence is obtained based on the shortened position sequence and the second cyclic shift, wherein the shortened position sequence comprises part of elements of the position sequence, and the shortened position sequence has a length equal to the total number of the REs for reference signal transmission.

28. The method according to claim 26 or 27, wherein in a case that at least one second condition is satisfied, wherein the at least one second condition comprises the first parameter of the first target position set is less than the total number of the REs for reference signal transmission, the first position sequence is obtained based on an extended position sequence and the first cyclic shift, and the second position sequence is obtained based on the extended position sequence and the second cyclic shift, wherein the extended position sequence comprises the elements of the position sequence with part of the elements of the position sequence being repeated, and the extended position sequence has a length equal to the total number of the REs for reference signal transmission.

29. The method according to any one of claims 18 to 21, wherein positions of the first REs are indicated by the first position sequence and a first comb value; and positions of the second REs are indicated by the second positionsequence and a second comb value.

30. The method according to claim 29, wherein the first comb value is equal to the second comb value, the at least one target position set comprises a first target position set and / or a second target position set, wherein the at least one target position set is determined based on a first parameter of the one target position set, a total number of REs for reference signal transmission and the first comb value or the second comb value.

31. The method according to claim 29, wherein the first comb value is greater than the second comb value, and the first comb value is an integer multiple of the second comb value; wherein the at least one target position set comprises a first target position set and a second target position set, wherein the first target position set is determined based on a first parameter of the first target position set, a total number of REs for reference signal transmission and the first comb value, and the second target position set is determined based on a first parameter of the second target position set, the total number of the REs for reference signal transmission, the first comb value and the second comb value; wherein the first position sequence is obtained based on the first target position set and a third cyclic shift, and the second position sequence is obtained based on the first target position set, a fourth cyclic shift different from the third cyclic shift, and the second target position set.

32. The method according to any one of claims 22 to 31, wherein each of the at least one target position set has a third parameter, and the third parameter is related to a number of intersections between the REs on which the first reference signal is transmitted and the REs on which the second reference signal is transmitted.

33. The method according to any one of claims 18 to 32, wherein the at least one target position set is determined by a base station and a user equipment, respectively, according to a pre-defined rule, or the at least one target position set is determined by a base station and indicated from the base station to a user equipment.

34. The method according to any one of claims 20 to 33, wherein the first cyclic shift and the second cyclic shift are indicated from a base station to a user equipment.

35. A wireless communication apparatus, comprising modules for performing the method according to any one of claims 1 to 17.

36. A wireless communication apparatus, comprising modules for performing the method according to any one of claims 18 to 34.

37. A computer-readable medium storing computer execution instructions which, when executed by a processor, causes the processor to execute the method according to any one of claims 1 to 17 or the method according to any one of claims 18 to 34.

38. A computer program product comprising program code for performing the method according to any one of claims 1 to 17 or the method according to any one of claims 18 to 34.

39. A computer program comprising computer execution instructions which, when executed by a processor, cause the processor to execute the method according to any one of claims 1 to 17 or the method according to any one of claims 18 to 34.

40. A chip, comprising an input / output (I / O) interface and a processor, wherein the processor is configured to call and run computer execution instructions stored in a memory, to enable a device installing with the chip to execute the method according to any one of claims 1 to 17 or the method according to any one of claims 18 to 34.

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