CN108282309B

CN108282309B - Reference signal transmission method and device

Info

Publication number: CN108282309B
Application number: CN201710011417.1A
Authority: CN
Inventors: 丁梦颖; 胡远洲; 王宗杰; 彭金磷
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2017-01-06
Filing date: 2017-01-06
Publication date: 2021-09-07
Anticipated expiration: 2037-01-06
Also published as: CN108282309A

Abstract

The application provides a transmission method and equipment of a reference signal, wherein the method comprises the following steps: the sending equipment transforms a frequency domain reference signal to a time domain to generate a time domain reference signal, wherein the frequency domain reference signal comprises a first reference signal sequence and at least one second reference signal sequence which are respectively mapped on N frequency domain resource groups with the same length, the first reference signal sequence is a frequency domain constant amplitude sequence, the second reference signal sequence is a sequence of the first reference signal sequence after linear phase rotation, and N is an integer greater than 1; and transmitting the time domain reference signal. The transmission method of the reference signal can improve the data transmission performance by sending the reference signal with low PAPR/RCM.

Description

Reference signal transmission method and device

Technical Field

The present application relates to the field of communications, and in particular, to a reference signal design technique in a wireless communication system.

Background

In wireless communication systems, a Reference Signal (RS), also called pilot Signal, is a predefined Signal that is transmitted by a transmitting device to a receiving device on predefined resources. The receiving device may obtain channel related information according to the received reference signal to complete channel estimation or channel measurement. The channel measurement results can be used for resource scheduling and link adaptation, and the channel estimation results can be used for the receiving device to demodulate data. In general, different reference signals need to be orthogonal in order to accurately obtain channel related information. The multiple reference signals orthogonal to each other may be provided by time division, frequency division, or code division. In a Long Term Evolution (LTE) system, an uplink reference signal includes an uplink demodulation reference signal (DMRS) and an uplink Sounding Reference Signal (SRS), and a downlink reference signal includes a cell-specific reference signal (CRS), a downlink DMRS, a channel state information reference signal (CSI-RS), a multimedia broadcast multicast single frequency network reference signal (MBSFN RS), and a Positioning Reference Signal (PRS).

In an LTE system, there are two ways for resource multiplexing between User Equipments (UEs), one is that time-frequency resources between UEs are not overlapped at all, and resource multiplexing is performed in a time-division or frequency-division manner; and the other is that the time-frequency resources between the UEs are completely overlapped, and the resources are multiplexed in a space division mode. When the resources among the UEs are multiplexed in a time division or frequency division mode, the reference signals of different UEs are also orthogonal in the time division or frequency division mode; when the resources between UEs are multiplexed in a space division manner, the reference signals of different UEs may be Orthogonal to each other through Orthogonal Cover Codes (OCCs) in time, frequency, time, or frequency domains, or may also be Orthogonal to each other through different linear phase rotations of the same sequence.

In the fifth generation (5)^thgeneration,5G) New Radio (NR) of a mobile communication system, for a scenario where multiple UEs or multiple transmit ports share the same or partially the same time-frequency resources, a method of blocking reference signals (block references signals) is proposed to improve orthogonality between reference signals of different UEs or different transmit ports. The scheme of the block reference signal divides the reference signal of each UE into a plurality of blocks, and the reference signals of different UEs are ensured to be orthogonal in the blocks, so that the reference signals of different UEs are ensured to be orthogonal integrally. After the block reference signal is introduced, the time frequency resources of the two UEs can share the resources by taking the block size as the granularity, and the time frequency resources of the two UEs which are subjected to space division multiplexing are not required to be completely overlapped, so that the resource allocation between the UEs is more flexible.

However, the introduction of the block reference signal may cause an increase in a peak-to-average power ratio (PAPR) and a Raw Cubic Metric (RCM) of the reference signal, and further may cause a reduction in accuracy of measurement of channel-related information by a receiving device and a reduction in data transmission performance when a transmission power of a cell edge user is limited. .

Disclosure of Invention

The application provides a data transmission method and equipment, which are used for reducing the PAPR/RCM of a block reference signal and further improving the data transmission performance.

In a first aspect, a method for generating a frequency domain reference signal is provided, including: allocating a reference signal sequence for a reference signal, wherein the reference signal sequence comprises a first reference signal sequence and at least one second reference signal sequence, the first reference signal sequence is a frequency domain constant amplitude sequence, and the second reference signal sequence is a sequence after the linear phase of the first reference signal sequence is rotated; and mapping the reference signal sequences to frequency domain resources allocated to the reference signals respectively to generate frequency domain reference signals, wherein the frequency domain resources allocated to the reference signals comprise N frequency domain resource groups, and N is an integer greater than 1.

The reference signal generated by the method has the characteristic of low PAPR/RCM, and when the reference signal is applied to a communication system, the data transmission performance can be improved. The generation of the reference signal may be implemented in the module of the transmitting device or in the module of the receiving device.

In a possible implementation manner of the first aspect, the sequences mapped to the (N +1) th frequency-domain resource group are sequences mapped to the (N) th frequency-domain resource group after linear phase rotation, where the (N) th frequency-domain resource group and the (N +1) th frequency-domain resource group are two frequency-domain resource groups of the N frequency-domain resource groups with the same length.

In a possible implementation manner of the first aspect, a value of a phase of the linear phase rotation is associated with the number N of the frequency-domain resource groups.

In one possible implementation manner of the first aspect, when the number N of frequency-domain resource sets is an even number, the phase of the linear phase rotation is α ═ 2d +1 · pi, where d is an integer.

In one possible implementation manner of the first aspect, when the number N of frequency-domain resource sets is an odd number, the phase of the linear phase rotation is α ═ 2d · pi, where d is an integer.

In a possible implementation manner of the first aspect, the references in the q-th frequency-domain resource group in the p-th resource group cluster of the N frequency-domain resource groups are mappedThe signal sequence is defined as R (p.K + q, M), wherein p and q are integers which are more than or equal to zero, K is an integer which is more than 1, M is the serial number of an element of the reference signal sequence, M is an integer which is more than or equal to 0 and less than or equal to M-1, M is the length of the reference signal sequence, p.K + q is less than N, and q is the serial number of a frequency domain resource group in the resource group cluster and is more than or equal to 0 and less than or equal to q and less than or equal to K-1; the reference signal sequence R (p.K + q, m) mapped to each frequency-domain resource group in the p-th resource group cluster is the same as the reference signal sequence R (q, m) mapped to each frequency-domain resource group in the 0-th resource group cluster, wherein p is larger than zero; for the 0 th resource group cluster, the reference signal sequences R (q, m) mapped on the q-th frequency-domain resource group are phase-rotated sequences of the reference signal sequences R (0, m) mapped on the 0 th frequency-domain resource group,

wherein j is an imaginary unit, q is not less than 1, alpha_qA phase of a reference signal sequence mapped on the q-th frequency-domain resource group in the 0 th resource group cluster is rotated relative to a linear phase of a reference signal sequence mapped on the 0 th frequency-domain resource group in the 0 th resource group cluster_qAre real numbers.

In a possible implementation manner of the first aspect, the N sequences are multiplied by N complex coefficients, and then the N sequences multiplied by the complex coefficients are mapped to the N frequency-domain resource groups, respectively, so as to obtain the reference signal of the frequency domain, where the amplitudes of the N complex coefficients are all 1.

In a second aspect, a method for transmitting a reference signal is provided, including: the sending equipment transforms a frequency domain reference signal to a time domain to generate a time domain reference signal, wherein the frequency domain reference signal comprises a first reference signal sequence and at least one second reference signal sequence which are respectively mapped on N frequency domain resource groups with the same length, the first reference signal sequence is a frequency domain constant amplitude sequence, the second reference signal sequence is a sequence of the first reference signal sequence after linear phase rotation, and N is an integer greater than 1; and transmitting the time domain reference signal.

In a possible implementation manner of the second aspect, the transmitting device generates the reference signal in the frequency domain by the method in the first aspect or any possible implementation manner of the first aspect.

In a third aspect, a method for transmitting a reference signal is provided, including: receiving a reference signal of a time domain; the method comprises the steps of converting a reference signal of a time domain to a frequency domain to generate a reference signal of the frequency domain, wherein the reference signal of the frequency domain comprises a first reference signal sequence and at least one second reference signal sequence which are respectively mapped on N frequency domain resource groups with the same length, the first reference signal sequence is a frequency domain constant amplitude sequence, the second reference signal sequence is a sequence obtained by linear phase rotation of the first reference signal sequence, and N is an integer greater than 1.

In a possible implementation manner of the third aspect, the receiving device generates the reference signal of the frequency domain by the method in the first aspect or any possible implementation manner of the first aspect.

In a fourth aspect, there is provided an apparatus comprising means to perform the method of the first aspect or any possible implementation manner of the first aspect.

In a fifth aspect, a communication device is provided, which includes a processing unit and a sending unit to execute the method of the second aspect or any possible implementation manner of the second aspect.

A sixth aspect provides a communication apparatus comprising a processor, a memory, and a transceiver to perform the method of the second aspect or any possible implementation manner of the second aspect.

In a seventh aspect, a communication apparatus is provided, which includes a processing unit and a sending unit, to execute the method of the third aspect or any possible implementation manner of the third aspect.

In an eighth aspect, there is provided a communication device comprising a processor, a memory and a transceiver to perform the method of the third aspect or any possible implementation manner of the third aspect.

A ninth aspect provides a computer-readable storage medium having stored therein instructions which, when run on a computer, cause the computer to perform the method of the first aspect or any possible implementation of the first aspect.

A tenth aspect provides a computer-readable storage medium having stored therein instructions which, when run on a computer, cause the computer to perform the method of the second aspect or any possible implementation of the second aspect.

In an eleventh aspect, there is provided a computer-readable storage medium having stored therein instructions, which, when run on a computer, cause the computer to perform the method of the third aspect or any possible implementation of the third aspect.

In a twelfth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the first aspect or any possible implementation of the first aspect.

In a thirteenth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the second aspect or any possible implementation of the second aspect.

In a fourteenth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the third aspect or any possible implementation of the third aspect.

Drawings

Fig. 1 is a schematic architecture diagram of a communication system applied in an embodiment of the present application;

fig. 2 is a schematic diagram of a ZC sequence generating a reference signal sequence by cyclic extension or truncation according to an embodiment of the present application;

fig. 3 is a schematic flowchart of a method for generating a frequency domain reference signal according to an embodiment of the present application;

fig. 4 is a schematic diagram of a frequency-domain resource group including M minimum time-frequency resource units according to an embodiment of the present application;

fig. 5 is a schematic diagram of N frequency-domain resource groups according to an embodiment of the present application;

fig. 6 is a schematic diagram of transmission of a block reference signal according to an embodiment of the present application;

fig. 7 is a schematic diagram of transmission of a block reference signal with phase rotation according to an embodiment of the present application;

fig. 8 is a schematic diagram of another transmission of a block reference signal with phase rotation according to an embodiment of the present application;

fig. 9 is a flowchart illustrating a reference signal transmission method applied to a sending device according to an embodiment of the present application;

fig. 10 is a flowchart illustrating a reference signal transmission method applied to a receiving device according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of another communication device provided in an embodiment of the present application;

fig. 13 is a schematic structural diagram of another communication device provided in an embodiment of the present application;

fig. 14 is a schematic structural diagram of another communication device according to an embodiment of the present application.

Detailed Description

The sending device and the receiving device in the embodiments of the present application may be any sending device and receiving device that perform data transmission in a wireless manner. The transmitting device and the receiving device may be any device with wireless transceiving function, including but not limited to: a base station (e.g., a base station NodeB, an evolved base station eNodeB, a base station in the fifth generation (5G) communication system, a base station or network device in a future communication system, an access node in a WiFi system, a wireless relay node, a wireless backhaul node), and a User Equipment (UE). The UE may also be referred to as a Terminal, a Mobile Station (MS), a Mobile Terminal (MT), or the like. The UE may communicate with one or more core networks through a Radio Access Network (RAN), or may access a distributed network through a self-organizing or authorization-free manner, and may also access a wireless network through other manners to communicate, and may also directly perform wireless communication with other UEs, which is not limited in this embodiment of the present application.

The sending device and the receiving device in the embodiment of the application can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; can also be deployed on the water surface; it may also be deployed on airborne airplanes, balloons, and satellites. The UE in the embodiment of the present application may be a mobile phone (mobile phone), a tablet computer (Pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), and the like. The embodiments of the present application do not limit the application scenarios.

Fig. 1 is a schematic architecture diagram of a communication system to which an embodiment of the present application is applied. As shown in fig. 1, the communication system includes a core network device 110, a base station 120, a UE130, and a UE140, which are connected by wireless connection, wired connection, or other means, and the UE130 and the UE140 may be stationary or mobile. Fig. 1 is a schematic diagram, and other network devices and/or other terminal devices, which are not shown in fig. 1, may be included in the communication system.

The embodiments of the present application may be applicable to downlink data transmission, may also be applicable to uplink data transmission, and may also be applicable to device-to-device (D2D) data transmission. For example, for downlink data transmission, the transmitting device is a base station, and the corresponding receiving device is a UE; for uplink data transmission, the sending device is a UE, and the corresponding receiving device is a base station; for data transmission of D2D, the transmitting device is a UE and the corresponding receiving device is also a UE. The embodiments of the present application do not limit this.

In order to reduce PAPR/RCM when a transmitting device transmits a reference signal, a constant amplitude (constant amplitude) sequence, also called a constant envelope sequence, may be selected as the reference signal sequence. For example, uplink reference signals in a Long Term Evolution (LTE) system employ Zadoff-Chu (ZC) sequences and Quadrature Phase Shift Keying (QPSK) sequences.

Taking the application of ZC sequences in uplink reference signals of an LTE system as an example, a brief description will be given to the process of generating reference signal sequences by ZC sequences.

Length M_ZCThe u-th root sequence of the ZC sequence of (1) is defined as:

wherein u is less than M_ZCAnd with M_ZCA prime integer, u being the root of the ZC sequence, k being an integer and j being an imaginary unit. The ZC sequence determined by u may also be referred to as a length M_ZCThe u-th ZC root sequence of (1). ZC sequences have good autocorrelation, i.e., the sequences have large autocorrelation peaks. The method has good cross correlation between two ZC sequences with the same length but different roots, namely the cross correlation value is small. In order to maximize the length as M_ZCThe number of root sequences of ZC sequences of (1), usually M_ZCTaken as prime numbers. However, in the examples of the present application, M_ZCThe number may be prime or non-prime, and the embodiment of the present application is not limited thereto.

It is understood that the numbering of the array or sequence, for example, the value of k, may have different numbering modes, and may start counting from 1 to zero, which is not limited by the embodiments of the present application.

When the length of the reference signal sequence does not coincide with the ZC sequence, it can be determined from the ZC sequence X_u(k) Generating a base sequence (base sequence) of a reference signal sequence

As shown in equation (2):

wherein M is the element number of the base sequence, M is an integer, M is more than or equal to 0 and less than M, M is the length of the base sequence, and M is an integer more than 1. When M is larger than M, as shown in FIG. 2 (a)_ZCEquation (2) can be understood as referring to the length M_ZCThe ZC sequence of (1) obtains a base sequence with the length of M through cyclic extension; when M is smaller than M, as shown in FIG. 2 (b)_ZCEquation (2) can be understood as referring to the length M_ZCThe ZC sequence of (2) is truncated to obtain a base sequence of length M.

For example, to generate a base sequence of a reference signal of length 48, it can be obtained by cyclic extension of a ZC sequence of length 47. The method comprises the steps of obtaining a group of basic reference signal sequences by performing cyclic extension on ZC sequences with the same length but different roots, wherein the cross correlation among the basic reference signal sequences is small but not zero.

To further obtain more reference signal sequences, different frequency-domain linear phase rotations (linear phase rotations) may be performed on the base sequence of the reference signal sequence. Different reference signal sequences obtained by performing different linear phase rotations on the base sequence of the same reference signal sequence are completely orthogonal, so that the reference signal sequences obtained by the linear phase rotations have no interference. Sequence of

Obtaining a sequence R after linear phase rotation_u,α(m) as shown in formula (3):

where α is a phase of linear phase rotation, α is a real number, and assuming that α ═ c · pi)/6, c may take a value from 0 to 11, so that 12 different mutually orthogonal reference signal sequences can be obtained from one basic reference signal sequence through different phase rotations. Performing linear phase rotation in the frequency domain corresponds to performing cyclic shift (cyclic shift) in the time domain, and the shift of the cyclic shift is determined by the phase of the linear phase rotation.

It is understood that the above process of generating a reference signal sequence from a ZC sequence is also applicable to other constant amplitude sequences, and is not described herein.

As shown in fig. 3, an embodiment of the present application provides a method for generating a frequency domain reference signal. The reference signal generated by the method has the characteristic of low PAPR/RCM, and when the reference signal is applied to a communication system, the data transmission performance can be improved. The generation of the reference signal may be implemented in the module of the transmitting device or in the module of the receiving device.

And S310, allocating a reference signal sequence for the reference signal, wherein the reference signal sequence comprises a first reference signal sequence and at least one second reference signal sequence, the first reference signal sequence is a frequency domain constant amplitude sequence, and the second reference signal sequence is a sequence after the first reference signal sequence is linearly phase-rotated.

It will be appreciated that the reference signal may be assigned to the wireless link between the sending device and the receiving device, or may be assigned to a particular antenna port (port) of the sending device.

Taking ZC sequence as an example, the first reference signal sequence may be a base sequence of the reference signal sequence determined by the above formula (2), or may be a sequence based on linear phase rotation of the base sequence determined by the above formula (3); the second reference signal sequence is a linear phase-rotated sequence of the first reference signal sequence. When the first reference signal sequence and the second reference signal sequence are both base sequence linear phase rotated sequences, the rotational phase of the linear phase rotation of the first reference signal sequence is different from the rotational phase of the second reference signal sequence. The second reference signal sequence may be one or more. When the second reference signal sequence is multiple, the multiple second reference signal sequences may be the same, different, or partially the same. For example, the second reference signal sequence may be a sequence obtained by phase-rotating the base sequence, and may be reused multiple times. For another example, the second reference signal sequence may be a sequence obtained by performing the same phase rotation on the basis of the base sequence. For another example, the second reference signal sequence may be a different sequence obtained by different phase rotations based on the base sequence.

The reference signal sequence allocated for the reference signal includes N sequences, where N is an integer greater than 1. That is, the total number of the first reference signal sequence and the second reference signal sequence is N. For example, the reference signal may be assigned 1 first reference signal sequence, N-1 second reference signal sequences. The N-1 second reference signal sequences may be the same sequence, or different sequences, or partially identical sequences.

Assume that the first reference signal sequence uses R₁(m) the second reference signal sequence is represented by R₂(M) represents, wherein M is the sequence number of the elements of the sequence, M is an integer and 0. ltoreq. m.ltoreq.M-1, and the lengths of the first reference signal sequence and the second reference signal sequence are both M. The relationship between the second reference signal sequence and the first reference signal sequence can be expressed by equation (4):

R₂(m)＝e^j·α·mR₁(m) (4)

where α is the phase of the linear phase rotation, and α is a real number.

It is to be understood that the embodiments of the present application do not limit the specific sequence type of the frequency domain constant amplitude sequence, and may be a ZC sequence, a QPSK sequence, or other frequency domain constant amplitude sequences.

And S320, mapping the reference signal sequences to frequency domain resources allocated to the reference signals respectively to generate frequency domain reference signals, where the frequency domain resources allocated to the reference signals include N frequency domain resource groups, and N is an integer greater than 1.

Each frequency domain resource group comprises M minimum time frequency resource units in one time domain symbol, and M is an integer greater than 1. The time domain symbol may be an Orthogonal Frequency Division Multiplexing (OFDM) symbol, or a single carrier frequency division multiple access (SC-FDMA) symbol; the minimum time-frequency resource element may be defined differently in different systems, for example, in an LTE system, the minimum time-frequency resource element is a Resource Element (RE).

And selecting one sequence from the first reference signal sequence and the at least one second reference signal sequence to map on one frequency-domain resource group in the N frequency-domain resource groups. And M elements in the sequence are respectively mapped to M minimum time-frequency resource units in the frequency domain resource group. Each of the N frequency-domain resource groups has a corresponding sequence, and the N sequences mapped to the N frequency-domain resource groups include a first reference signal sequence and at least one second reference signal sequence. There are various ways of generating the first reference signal sequence and the second reference signal sequence. In one example, the sequences may be stored in a memory. For example, a first reference signal sequence and/or a second reference signal sequence, or N sequences, are generated in advance, the sequences are stored in a memory, when the reference signals need to be generated, the sequences are directly called or read from the memory, and the sequences are respectively mapped to frequency-domain resource groups to generate the frequency-domain reference signals. In another example, the first reference signal sequence and the second reference signal sequence may be generated in real time according to the above reference signal sequence generation method according to a parameter based on sequence correlation when needed. In yet another example, portions of the sequence may be saved in memory, while other sequences are generated in real-time as needed. For example, the first reference signal sequence may be generated in advance and stored in a memory, and the second reference signal sequence may be generated in real time as needed. This is not limited in this application.

In the embodiment of the present application, since the second reference signal sequence is a sequence of the first reference signal sequence after linear phase rotation, the first reference signal sequence and the second reference signal sequence are orthogonal to each other. At least two mutually orthogonal constant amplitude sequences are used as reference signal sequences and are respectively mapped to corresponding frequency domain resource groups, and the generated reference signals have the characteristic of low PAPR/RCM, so that the data transmission performance can be improved.

As shown in fig. 4, M minimum time-frequency resource units in a frequency-domain resource group may be continuous or comb-shaped. The M smallest time-frequency resource units in one frequency-domain resource group in (a) of fig. 4 are consecutive; in (b) of fig. 4, M smallest time-frequency resource units in one frequency-domain resource group are regularly comb-shaped; in (c) of fig. 4, M smallest time-frequency resource units in one frequency-domain resource group are irregularly comb-shaped.

As shown in fig. 5, the N frequency resource groups may be consecutive or non-consecutive. The N frequency-domain resource groups in (a) in fig. 5 are consecutive in the frequency domain; in (b) of fig. 5, the N frequency-domain resource groups are non-consecutive in the frequency domain and are equally spaced; the N frequency-domain resource groups in (c) of fig. 5 are non-consecutive in the frequency domain and are irregularly spaced.

The above is described by taking an example that the length of each frequency domain resource group in the N frequency domain resource groups is the same, and it can be understood that the length of each frequency domain resource group in the N frequency domain resource groups may also be different or partially the same, which is not limited in this application.

A further description of a possible design of the sequences mapped into the N resource groups follows.

Sequence design one: and the sequence mapped to the (N +1) th frequency domain resource group is a sequence mapped to the (N) th frequency domain resource group after linear phase rotation, wherein the (N) th frequency domain resource group and the (N +1) th frequency domain resource group are two frequency domain resource groups in the N frequency domain resource groups with the same length.

Specifically, the sequence mapped on the (N +1) th frequency domain resource group is R (N +1, m), the sequence mapped on the nth frequency domain resource group is R (N, m), the sequence R (N +1, m) is obtained by performing linear phase rotation on the sequence R (N, m), wherein N is an integer, N is greater than or equal to 0 and less than or equal to N-2, and the phase of the linear phase rotation is alpha.

The value of the phase α may be selected to be a fixed value, for example, when α ═ pi, the phases of the sequences mapped into resource group 0 to resource group 5 are rotated with respect to the linear phases of the sequences mapped into resource group 0 by {0, pi, 0, pi }; when α ═ pi/2, the phases of the sequences mapped into resource group 0 to resource group 5 are rotated with respect to the linear phases of the sequences mapped into resource group 0 by {0, pi/2, pi, 3 pi/2, 0, pi/2 }, respectively; when α is 0, the phases of the sequences mapped to resource group 0 to resource group 5 rotated with respect to the linear phase of the sequence mapped to resource group 0 are {0, 0, 0, 0, 0, 0}, respectively.

The value of the phase α may also be associated with the number N of frequency-domain resource groups, for example, when N is an even number, α ═ 2d +1 · π; when N is an odd number, α ═ 2d · pi, where d is an integer.

Assume that the sequence mapped onto resource group 0 is R_u(m), the sequence mapped onto the N resource groups can be represented by formula (5):

the following provides beneficial effects of the embodiments of the present application in a specific scenario. The scenario is assumed to be: each frequency-domain resource group has a size of 4 RBs, namely 48 subcarriers; m is 48, R_u(m) is a cyclic extension of a ZC sequence of length 47 and root 10; with R_u(m) generating a sequence of a length of 6 frequency-domain resource groups for a base sequence

The beneficial effects of the embodiments of the present application in this scenario are shown in table 1, and example 1 in table 1 is to compare R_u(m) mapping onto each set of frequency-domain resources to generate a sequence

Example 2 is a sequence generated according to equation (5). As can be seen from table 1, the reference signal sequence generated by using equation (5) of the embodiment of the present application can significantly reduce the PAPR/RCM of the reference signal sequence.

TABLE 1

	PAPR(dB)	RCM(dB)
			Example 1	13.07	16.83
Example 2	9.63	11.75

Considering that N sequences mapped to N resource groups are phase-rotated respectively as shown in fig. 7 and 8, the phase-rotated sequences mapped to N resource groups can be represented by formula (6):

the following provides another specific scenario, and the embodiments of the present application have beneficial effects. The scenario is assumed to be: each frequency-domain resource group has a size of 4 RBs, namely 48 subcarriers; m is 48, R_u(m) is a cyclic extension of a ZC sequence of length 47 and root 10; with R_u(m) generating a sequence of a length of 6 frequency-domain resource groups for a base sequence

The phase rotation vector of length 6 is

The beneficial effects of the embodiment of the present application in this scenario are shown in table 2, and example 3 in table 2 is to combine R_u(m) mapping onto each set of frequency-domain resources to generate a sequence

Simultaneously, performing phase rotation on each frequency domain resource group; example 4 is a sequence generated according to equation (6) while phase-rotating each set of frequency-domain resources. As can be seen from table 2, the PAPR/RCM of the reference signal sequence generated by equation (6) in the embodiment of the present application can be further reduced in the scenario of performing phase rotation on each frequency-domain resource group.

TABLE 2

	PAPR(dB)	RCM(dB)
			Example 3	8.08	6.61
Example 4	7.07	5.46

Considering the overall linear phase rotation of the sequences mapped onto the N resource groups, the sequences mapped onto the N resource groups after the linear phase rotation can be represented by formula (7) and formula (8):

and (2) designing a sequence:

a reference signal sequence mapped in a qth frequency-domain resource group in a pth resource group cluster in the N frequency-domain resource groups is defined as R (p · K + q, M), wherein p and q are integers greater than or equal to zero, K is an integer greater than 1, M is a serial number of an element of the reference signal sequence, M is an integer and 0 ≤ M-1, M is a length of the reference signal sequence, p · K + q < N, q is a serial number of a frequency-domain resource group within the resource group cluster and 0 ≤ q ≤ K-1;

the reference signal sequence R (p.K + q, m) mapped to each frequency-domain resource group in the p-th resource group cluster is the same as the reference signal sequence R (q, m) mapped to each frequency-domain resource group in the 0-th resource group cluster, wherein p is larger than zero;

for the 0 th resource group cluster, the reference signal sequences R (q, m) mapped on the q-th frequency-domain resource group are phase-rotated sequences of the reference signal sequences R (0, m) mapped on the 0 th frequency-domain resource group,

Taking N-12 and K-3 as an example, p and q take the values shown in table 3, and the phase { α { (a) } is₁,α₂The value of can be

Or

And the like.

TABLE 3

Resource group number n	p	q
			0	0	0
1	0	1
			2	0	2
3	1	0
			4	1	1
5	1	2
			6	2	0
7	2	1
			8	2	2
9	3	0
			10	3	1
11	3	2

The following provides the beneficial effects of the above embodiments in a specific scenario. The scenario is assumed to be: each frequency-domain resource group has a size of 4 RBs, namely 48 subcarriers; m is 48, R_u(m) is a cyclic extension of a ZC sequence of length 47 and root 10; with R_u(m) generating a sequence of 3 frequency-domain resource groups in length for the base sequence

Phase { alpha }₁,α₂The value of is

The beneficial effects of the above embodiment are shown in table 4, and example 5 in table 4 is that R is_u(m) mapping onto each set of frequency-domain resources to generate a sequence

Example 6 is a sequence generated according to the above example. As can be seen from table 4, the reference signal sequence generated by the above embodiment can significantly reduce PAPR/RCM of the reference signal sequence.

TABLE 4

	PAPR(dB)	RCM(dB)
			Example 5	10.07	11.0
Example 6	5.05	4.51

The following provides the beneficial effects of the above embodiment in another specific scenario. The scenario is assumed to be: each frequency-domain resource group has a size of 4 RBs, namely 48 subcarriers; m is 48, R_u(m) is a cyclic extension of a ZC sequence of length 47 and root 10; with R_u(m) generating a sequence of 3 frequency-domain resource groups in length for the base sequence

Phase { alpha }₁,α₂The value of is

The length-3 phase rotation vector is { -1,1,1 }. The beneficial effects of the above embodiment are shown in table 5, and example 7 in table 5 is that R is_u(m) mapping onto each set of frequency-domain resources to generate a sequence

Example 8 isAccording to the sequence generated by the embodiment, each frequency domain resource group is subjected to phase rotation at the same time. As can be seen from table 5, the reference signal sequence generated by using the above embodiment can further reduce PAPR/RCM of the reference signal sequence in the scenario of performing phase rotation on each frequency-domain resource group.

TABLE 5

	PAPR(dB)	RCM(dB)
			Example 7	7.54	6.05
Example 8	5.09	4.47

When K is 2 and N is an even number, the sequence design in the first sequence design can be referred to, and the phase α is₁And d is an integer, wherein the value is (2. d + 1). pi.

And (3) designing a sequence: when the number N of the frequency-domain resource groups is equal to 2, the second reference signal sequence is a sequence after the linear phase rotation of the first reference signal sequence, the phase of the linear phase rotation is (2d +1) · pi, and d is an integer. The sequence mapped on the frequency-domain resource group 0 is a first reference signal sequence, and the sequence mapped on the frequency-domain resource group 1 is a second reference signal sequence after the first reference signal sequence is linearly phase-rotated by (2d +1) · pi.

The above embodiments are given below in a specific fieldHas the advantages of good effect. The scenario is assumed to be: each frequency domain resource group is 4 RBs, namely 48 subcarriers, and M is 48; r_u(m) is a cyclic extension of a ZC sequence of length 47 and root 10; with R_u(m) generating a sequence of 2 frequency-domain resource groups in length for the base sequence

The beneficial effects of the above embodiment are shown in table 6, and example 9 in table 6 is that R is_u(m) mapping onto each set of frequency-domain resources to generate a sequence

Example 10 is a sequence generated according to the above example. As can be seen from table 6, the reference signal sequence generated by using the above embodiment can significantly reduce the PAPR/RCM of the reference signal sequence.

TABLE 6

	PAPR(dB)	RCM(dB)
			Example 9	8.33	7.79
Example 10	5.05	4.51

The following gives the benefits of the above embodiments in another specific scenarioAnd (5) effect. The scenario is assumed to be: each frequency domain resource group is 4 RBs, namely 48 subcarriers, and M is 48; r_u(m) is a cyclic extension of a ZC sequence of length 47 and root 10; with R_u(m) generating a sequence of 2 frequency-domain resource groups in length for the base sequence

The length 2 phase rotation vector is {1, -1 }. The beneficial effects of the above embodiment are shown in Table 7, and example 11 in Table 7 is that R is_u(m) mapping onto each set of frequency-domain resources to generate a sequence

Example 12 is the sequence generated according to the above embodiment, while phase-rotating each frequency-domain resource group. As can be seen from table 7, the reference signal sequence generated by using the above embodiment can further reduce PAPR/RCM of the reference signal sequence in the scenario of performing phase rotation on each frequency-domain resource group.

TABLE 7

	PAPR(dB)	RCM(dB)
			Example 11	7.73	7.78
Example 12	5.09	4.47

As shown in fig. 9, an embodiment of the present application provides a method for transmitting a reference signal.

S910, the sending device transforms the frequency domain reference signal to the time domain to generate a time domain reference signal, wherein the frequency domain reference signal includes a first reference signal sequence and at least one second reference signal sequence which are respectively mapped to N frequency domain resource groups with the same length, the first reference signal sequence is a frequency domain constant amplitude sequence, the second reference signal sequence is a sequence of the first reference signal sequence after linear phase rotation, and N is an integer greater than 1. The generation process of the reference signal in the frequency domain may refer to the process shown in fig. 2.

As shown in fig. 6, after the N sequences are mapped to the N frequency-domain resource groups, frequency-domain to time-domain transformation is performed to obtain a time-domain reference signal. Common frequency domain to time domain transformation methods are Inverse Discrete Fourier Transform (IDFT) and Inverse Fast Fourier Transform (IFFT), but the embodiments of the present application do not limit this.

Optionally, as shown in fig. 7, the sending device multiplies the N sequences by N complex coefficients, where the processing procedure is also referred to as phase rotation, and then maps the N sequences multiplied by the complex coefficients to N frequency-domain resource groups, so as to obtain a frequency-domain reference signal, where the amplitudes of the N complex coefficients are all 1; then, the transmitting apparatus transforms the reference signal of the frequency domain to the time domain to generate a reference signal of the time domain. Complex coefficients in fig. 7

β_nIs a real number, when n is different in value, beta_nThe values of (A) may be the same or different.

Optionally, before transforming the frequency-domain reference signal into the time-domain reference signal, the transmitting device may further perform one or more linear phase rotations on the frequency-domain reference signal, which is equivalent to performing one or more time-domain cyclic shifts on the frequency-domain reference signal.

Optionally, as shown in fig. 8, the sending device may also perform phase rotation on N sequences in the frequency-domain reference signal, that is, multiply N complex coefficients, respectively, to obtain a second frequency-domain reference signal; then, the transmitting device transforms the second frequency domain reference signal to the time domain to generate a reference signal of the time domain.

Optionally, before transforming the second frequency-domain reference signal into the reference signal in the time domain, the sending device may further perform one linear phase rotation on the whole second frequency-domain reference signal, which is equivalent to performing one cyclic shift in the time domain on the second frequency-domain reference signal.

S920, the sending device sends the reference signal in the time domain.

It is understood that, before transmitting the reference signal in the time domain, the transmitting device may also perform digital-to-analog conversion (converting a digital signal into an analog signal) and carrier modulation (modulating a baseband signal onto a radio frequency carrier), and then transmit the signal through the antenna.

As shown in fig. 10, the embodiment of the present application provides another transmission method of a reference signal.

S1010, the receiving device receives a time domain reference signal.

It is understood that the receiving device receives a wireless signal from a wireless channel through an antenna, and the wireless signal includes the reference signal in the time domain.

And S1020, the receiving device transforms the time-domain reference signal to the frequency domain to generate a frequency-domain reference signal, wherein the frequency-domain reference signal includes a first reference signal sequence and at least one second reference signal sequence which are respectively mapped to N frequency-domain resource groups with the same length, the first reference signal sequence is a frequency-domain constant amplitude sequence, the second reference signal sequence is a sequence of the first reference signal sequence after linear phase rotation, and N is an integer greater than 1.

The receiving device measures the first reference signal sequence and the second reference signal sequence to obtain an estimation of a wireless channel parameter between the transmitting device and the receiving device, and the channel estimation result can be used for demodulating data transmitted by the transmitting device; or to obtain a measurement of the channel quality between the transmitting device and the receiving device, which may be used for link adaptation and resource allocation, etc., of data transmission between the transmitting device and the receiving device. The measurement result of the sequence can also be used for positioning measurement, and the application does not limit the use of the reference signal.

In order for the receiving device to measure the received frequency-domain reference signal, the receiving device may refer to the generation process of the frequency-domain reference signal as shown in fig. 2 to generate a frequency-domain reference signal identical to the frequency-domain reference signal generated by the transmitting device.

In practical application, the method for the sending device to acquire the reference signal sequence may be to acquire a generated reference signal sequence from a memory, or to generate the reference signal sequence in real time according to a relevant parameter of the reference signal sequence.

The method for acquiring the reference signal sequence related parameters by the sending equipment can be acquired from a memory, or the reference signal sequence can be uniformly distributed by the network equipment, and then the related parameters of the reference signal sequence are sent to the sending equipment by signaling, and the sending equipment acquires the reference signal sequence by using the related parameters of the reference signal sequence. The related parameter of the ZC sequence here may include at least one of a value indicating a length of the ZC sequence, a value of a root of the ZC sequence, and a value of a phase of the linear phase rotation. The network device here may be a base station NodeB, an evolved base station eNodeB, a base station in a 5G communication system, or other network device.

The receiving device also needs to acquire a reference signal sequence used by the received reference signal in order to complete the measurement of the reference signal. The method for acquiring the reference signal sequence by the receiving device may be to acquire a correlation parameter of the reference signal sequence and then use the parameter to generate the reference signal sequence. The method for acquiring the relevant parameters of the reference signal sequence by the receiving equipment comprises the following steps: the sending device may send the relevant parameters of the reference signal sequence to the receiving device through signaling after obtaining the relevant parameters of the reference signal sequence; or the network device may send the relevant parameters of the reference signal sequence to the receiving device through signaling.

The sending device and the receiving device may also obtain the relevant parameters of the reference signal sequence in an implicit manner, for example, implicitly determine the relevant parameters of the reference signal sequence in a manner of cell identification, slot number, and the like.

In the embodiments provided in the foregoing application, the reference signal sequence generation method and the reference signal transmission method provided in the embodiments of the application are introduced from the perspective of the transmitting device, the receiving device, and the interaction between the transmitting device and the receiving device. It is to be understood that each device, such as the transmitting device and the receiving device, etc., contains corresponding hardware structures and/or software modules for performing each function in order to realize the functions. Those of skill in the art will readily appreciate that the present application is capable of hardware or a combination of hardware and computer software implementing the various illustrative elements and method steps described in connection with the embodiments disclosed herein. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

Fig. 11 and 12 are schematic structural diagrams of two possible communication devices provided in an embodiment of the present application. The communication device realizes the function of the sending equipment in the reference signal transmission method embodiment, so that the beneficial effects of the reference signal transmission method can be realized. In the embodiment of the present application, the communication apparatus may be UE130 or UE140 or base station 120 shown in fig. 1, and may also be other transmitting side equipment that performs wireless communication using a reference signal.

As shown in fig. 11, the communication apparatus 1100 includes a processing unit 1110 and a transmitting unit 1120.

The processing unit 1110 is configured to transform a frequency-domain reference signal to a time domain to generate a time-domain reference signal, where the frequency-domain reference signal includes a first reference signal sequence and at least one second reference signal sequence that are respectively mapped to N frequency-domain resource groups with the same length, the first reference signal sequence is a frequency-domain constant amplitude sequence, the second reference signal sequence is a sequence obtained by rotating a linear phase of the first reference signal sequence, and N is an integer greater than 1.

A transmitting unit 1120, configured to transmit the time domain reference signal.

Further, before the processing unit 1110 transforms the reference signal of the frequency domain to the time domain to generate the reference signal of the time domain, the processing unit is further configured to multiply the N sequences by N complex coefficients, and then map the N sequences multiplied by the complex coefficients onto the N frequency-domain resource groups, respectively, to obtain the reference signal of the frequency domain, where the amplitudes of the N complex coefficients are all 1.

As shown in fig. 12, the communications apparatus 1200 includes a processor 1210, a transceiver 1220, and a memory 1230, where the memory 1230 may be used to store code executed by the processor 1210. The various components in the communications device 1200 communicate with each other via internal connection paths, such as control and/or data signals, over a bus.

The processor 1210 is configured to transform a frequency-domain reference signal to a time domain to generate a time-domain reference signal, where the frequency-domain reference signal includes a first reference signal sequence and at least one second reference signal sequence that are respectively mapped to N frequency-domain resource groups with the same length, the first reference signal sequence is a frequency-domain constant amplitude sequence, the second reference signal sequence is a sequence of the first reference signal sequence after linear phase rotation, and N is an integer greater than 1.

A transceiver 1220, configured to transmit the time domain reference signal.

Further, before the processor 1210 transforms the frequency-domain reference signal to the time domain to generate the time-domain reference signal, the processing unit is further configured to multiply the N sequences by N complex coefficients, respectively, and then map the N sequences multiplied by the complex coefficients onto the N frequency-domain resource groups, respectively, to obtain the frequency-domain reference signal, where the amplitudes of the N complex coefficients are all 1.

More detailed descriptions of the functions of the processing unit 1110, the processor 1210, the transmitting unit 1120, and the transceiver 1220 can be directly obtained by referring to the method embodiments, and are not repeated herein.

Fig. 13 and 14 are schematic structural diagrams of two other possible communication devices according to embodiments of the present application. The communication device realizes the function of the receiving device in the reference signal transmission method embodiment, so that the beneficial effects of the reference signal transmission method can be realized. In the embodiment of the present application, the communication apparatus may be UE130 or UE140 or base station 120 shown in fig. 1, and may also be other receiving side equipment that performs wireless communication using a reference signal.

As shown in fig. 13, the communication device 1300 includes a receiving unit 1310 and a processing unit 1320.

A receiving unit 1310 configured to receive a time domain reference signal.

The processing unit 1320 is configured to transform a time-domain reference signal to a frequency domain to generate a frequency-domain reference signal, where the frequency-domain reference signal includes a first reference signal sequence and at least one second reference signal sequence that are respectively mapped to N frequency-domain resource groups with the same length, the first reference signal sequence is a frequency-domain constant amplitude sequence, the second reference signal sequence is a sequence after linear phase rotation of the first reference signal sequence, and N is an integer greater than 1.

As shown in fig. 14, the communications apparatus 1400 includes a processor 1420, a transceiver 1410, and a memory 1430, wherein the memory 1430 can be used to store code that is executed by the processor 1420. The various components of the communication device 1400 communicate with each other via internal connection paths, such as control and/or data signals, via a bus.

A transceiver 1410 configured to receive a time domain reference signal.

The processor 1420 is configured to transform a reference signal in a time domain to a frequency domain to generate a reference signal in the frequency domain, where the reference signal in the frequency domain includes a first reference signal sequence and at least one second reference signal sequence, which are respectively mapped to N frequency-domain resource groups with the same length, the first reference signal sequence is a frequency-domain constant amplitude sequence, the second reference signal sequence is a sequence after the first reference signal sequence is linearly phase-rotated, and N is an integer greater than 1.

It will be appreciated that figures 12 and 14 only show one design of the communication device. In practical applications, the communication device may include any number of receivers and processors, and all communication devices that may implement embodiments of the present application are within the scope of the present application.

More detailed functional descriptions of the receiving unit 1310, the transceiver 1410, the processing unit 1320, and the processor 1420 can be directly obtained by referring to the above method embodiments, and are not repeated herein.

It is understood that the Processor in the embodiments of the present Application may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The general purpose processor may be a microprocessor, but may be any conventional processor.

The method steps in the embodiments of the present application may be implemented by hardware, or may be implemented by software instructions executed by a processor. The software instructions may be comprised of corresponding software modules that may be stored in Random Access Memory (RAM), flash Memory, Read-Only Memory (ROM), Programmable ROM (PROM), Erasable PROM (EPROM), Electrically EPROM (EEPROM), registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. Of course, the storage medium may also be integral to the processor. The processor and the storage medium may reside in an ASIC. In addition, the ASIC may reside in a transmitting device or a receiving device. Of course, the processor and the storage medium may reside as discrete components in a transmitting device or a receiving device.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in or transmitted over a computer-readable storage medium. The computer instructions may be transmitted from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

It is to be understood that the various numerical references referred to in the embodiments of the present application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of the present application.

It should be understood that, in the embodiment of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiment of the present application.

The above description is only a specific implementation of the embodiments of the present application, and any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope of the disclosure of the present application are intended to be covered by the protection scope of the embodiments of the present application.

Claims

1. A method for reference signal transmission, the method comprising:

transforming a frequency domain reference signal to a time domain to generate a time domain reference signal, wherein the frequency domain reference signal comprises a first reference signal sequence and at least one second reference signal sequence which are respectively mapped onto N frequency domain resource groups with the same length, the first reference signal sequence is a frequency domain constant amplitude sequence, the second reference signal sequence is a sequence of the first reference signal sequence after linear phase rotation, and N is an integer greater than 1;

and transmitting the reference signal of the time domain.

2. The method of claim 1, wherein the frequency-domain reference signal comprises a first reference signal sequence and at least one second reference signal sequence mapped to N frequency-domain resource groups of the same length, respectively, and comprises:

and the sequence mapped to the (N +1) th frequency domain resource group is a sequence mapped to the (N) th frequency domain resource group after linear phase rotation, wherein the (N) th frequency domain resource group and the (N +1) th frequency domain resource group are two frequency domain resource groups in the N frequency domain resource groups with the same length.

3. The method according to claim 1 or 2, wherein the value of the phase of the linear phase rotation is associated with the number N of frequency-domain resource groups.

4. The method according to claim 1 or 2, wherein when the number N of frequency-domain resource sets is an even number, the phase of the linear phase rotation is α ═ 2d +1 · π, where d is an integer.

5. The method according to claim 1 or 2, wherein when the number N of frequency-domain resource groups is an odd number, the phase of the linear phase rotation is α ═ 2d · π, where d is an integer.

6. The method of claim 1, wherein the frequency-domain reference signal comprises a first reference signal sequence and at least one second reference signal sequence mapped to N frequency-domain resource groups of the same length, respectively, and comprises:

7. The method of any one of claims 1, 2 or 6, wherein transforming the reference signal in the frequency domain to the time domain generates the reference signal in the time domain, comprising:

multiplying the N sequences by N complex coefficients respectively, and then mapping the N sequences multiplied by the complex coefficients onto the N frequency domain resource groups respectively to obtain the reference signals of the frequency domain, wherein the amplitudes of the N complex coefficients are all 1;

and transforming the reference signal of the frequency domain to the time domain to generate the reference signal of the time domain.

8. A communications apparatus, comprising:

the device comprises a processing unit, a processing unit and a processing unit, wherein the processing unit is used for transforming a frequency domain reference signal to a time domain to generate a time domain reference signal, the frequency domain reference signal comprises a first reference signal sequence and at least one second reference signal sequence which are respectively mapped to N frequency domain resource groups with the same length, the first reference signal sequence is a frequency domain constant amplitude sequence, the second reference signal sequence is a sequence after the linear phase of the first reference signal sequence is rotated, and N is an integer greater than 1;

and the sending unit is used for sending the reference signal of the time domain.

9. The apparatus of claim 8, wherein the frequency-domain reference signals comprise a first reference signal sequence and at least one second reference signal sequence respectively mapped to N frequency-domain resource groups of the same length, and wherein the method comprises:

10. The communication apparatus according to claim 8 or 9, wherein a value of a phase of a linear phase rotation is associated with the number N of frequency-domain resource groups.

11. The apparatus according to claim 8 or 9, wherein when the number N of frequency-domain resource sets is an even number, the phase of the linear phase rotation is α ═ 2d +1) · pi, where d is an integer.

12. The apparatus according to claim 8 or 9, wherein when the number N of the frequency-domain resource sets is an odd number, the phase of the linear phase rotation is α -2 d · pi, where d is an integer.

13. The apparatus of claim 8, wherein the frequency-domain reference signals comprise a first reference signal sequence and at least one second reference signal sequence respectively mapped to N frequency-domain resource groups of the same length, and wherein the method comprises:

14. The communication apparatus according to any one of claims 8, 9 or 13, wherein before the processing unit transforms the reference signal in the frequency domain to the time domain to generate the reference signal in the time domain, the processing unit is further configured to multiply N sequences by N complex coefficients, respectively, and then map the N sequences after being multiplied by complex coefficients onto the N sets of frequency-domain resources, respectively, to obtain the reference signal in the frequency domain, where the N complex coefficients have a magnitude of 1.

15. A method for reference signal transmission, the method comprising:

receiving a reference signal of a time domain;

the method comprises the steps of converting a reference signal of a time domain to a frequency domain to generate a reference signal of the frequency domain, wherein the reference signal of the frequency domain comprises a first reference signal sequence and at least one second reference signal sequence which are respectively mapped on N frequency domain resource groups with the same length, the first reference signal sequence is a frequency domain constant amplitude sequence, the second reference signal sequence is a sequence obtained by linear phase rotation of the first reference signal sequence, and N is an integer greater than 1.

16. The method of claim 15, wherein the frequency-domain reference signal comprises a first reference signal sequence and at least one second reference signal sequence mapped to N frequency-domain resource groups of the same length, respectively, and comprises:

17. The method according to claim 15 or 16, wherein the value of the phase of the linear phase rotation is associated with the number N of frequency-domain resource groups.

18. The method of claim 15 or 16, wherein when the number N of frequency-domain resource sets is an even number, the phase of the linear phase rotation is α ═ 2d +1) · pi, where d is an integer.

19. The method according to claim 15 or 16, wherein when the number N of the frequency-domain resource sets is an odd number, the phase of the linear phase rotation is α -2 d · pi, where d is an integer.

20. The method of claim 15, wherein the frequency-domain reference signal comprises a first reference signal sequence and at least one second reference signal sequence mapped to N frequency-domain resource groups of the same length, respectively, and comprises:

wherein j is an imaginary unit, q is not less than 1, alpha_qA phase of a reference signal sequence mapped on the q-th frequency-domain resource group in the 0 th resource group cluster is rotated relative to a linear phase of a reference signal sequence mapped on the 0 th frequency-domain resource group in the 0 th resource group cluster_qIs made ofAnd (4) counting.

21. A communications apparatus, comprising:

a receiving unit, configured to receive a reference signal in a time domain;

the device comprises a processing unit, a frequency domain generating unit and a processing unit, wherein the processing unit is used for transforming a time domain reference signal to a frequency domain to generate a frequency domain reference signal, the frequency domain reference signal comprises a first reference signal sequence and at least one second reference signal sequence which are respectively mapped to N frequency domain resource groups with the same length, the first reference signal sequence is a frequency domain constant amplitude sequence, the second reference signal sequence is a sequence of the first reference signal sequence after linear phase rotation, and N is an integer greater than 1.

22. The communications apparatus of claim 21, wherein the frequency-domain reference signals comprise a first reference signal sequence and at least one second reference signal sequence that are respectively mapped onto N groups of frequency-domain resources of the same length, comprising:

23. The communication apparatus according to claim 21 or 22, wherein a value of a phase of a linear phase rotation is associated with the number N of frequency-domain resource groups.

24. The apparatus according to claim 21 or 22, wherein when the number N of frequency-domain resource sets is an even number, the phase of the linear phase rotation is α ═ 2d +1) · pi, where d is an integer.

25. The apparatus according to claim 21 or 22, wherein when the number N of frequency-domain resource sets is an odd number, the phase of the linear phase rotation is α -2 d · pi, where d is an integer.

26. The communications apparatus of claim 21, wherein the frequency-domain reference signals comprise a first reference signal sequence and at least one second reference signal sequence that are respectively mapped onto N groups of frequency-domain resources of the same length, comprising: