CN107094042B

CN107094042B - Channel information indication method, system and receiving terminal equipment

Info

Publication number: CN107094042B
Application number: CN201610091218.1A
Authority: CN
Inventors: 郑毅; 童辉
Original assignee: China Mobile Communications Group Co Ltd
Current assignee: China Mobile Communications Group Co Ltd
Priority date: 2016-02-18
Filing date: 2016-02-18
Publication date: 2020-09-25
Anticipated expiration: 2036-02-18
Also published as: CN107094042A

Abstract

The invention discloses a channel information indicating method, which comprises the following steps: receiving end equipment receives a detection signal or a reference signal sent by sending end equipment; responding to the detection signal or the reference signal, and periodically feeding back first information and second information to the sending end equipment; the first information represents a frequency offset of a channel; the second information represents a frequency spread of a channel; the sending period of the first information is a first period; the sending period of the second information is a second period; the first period is greater than the second period. The invention also discloses a receiving end device and a channel indication system.

Description

Channel information indication method, system and receiving terminal equipment

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a method, a system, and a receiving end device for indicating channel information.

Background

The mobile communication system encounters a large doppler effect at a high frequency, thereby generating a large frequency offset in a channel. While for high frequency communications (e.g., 30 GHz-300 GHz), such frequency offsets may be more pronounced.

On the other hand, in the future, high frequency is applied to a radio access network, and a propagation path has certain uncertainty due to different positions of receiving ends. However, the magnitude of the frequency offset generated by the doppler effect is related to the incident angle of the receiving end, so that the frequency offset generated by the doppler effect has a certain uncertainty.

Because the frequency offset generated by the doppler effect can cause the channel to change rapidly, the communication system needs to detect and estimate the channel frequently according to the existing channel estimation mode, so as to ensure to obtain correct channel information, thus greatly increasing the amount of transmitted information.

Disclosure of Invention

In order to solve the existing technical problem, embodiments of the present invention provide a channel information indication method, a system and a receiving end device.

In order to achieve the above purpose, the technical solution of the embodiment of the present invention is realized as follows:

the embodiment of the invention provides a channel information indication method, which is applied to receiving end equipment and comprises the following steps:

receiving a detection signal or a reference signal sent by sending end equipment;

responding to the detection signal or the reference signal, and periodically feeding back first information and second information to the sending end equipment; the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading; wherein the content of the first and second substances,

the sending period of the first information is a first period; the sending period of the second information is a second period; the first period is greater than the second period.

In the foregoing solution, when the first information and the second information are periodically fed back to the sending-end device, the method further includes: periodically feeding back third information to the sending end equipment; the third information characterizes channel response caused by other factors except frequency offset and frequency spreading;

the feedback period of the third information is a third period; the second period is greater than the third period.

In the foregoing solution, before feeding back channel information to the sending end device periodically, the method further includes:

acquiring channel information by using the sounding signal or the reference signal;

and extracting the first information, the second information and the third information from the obtained channel information.

In the above scheme, the method further comprises:

and determining a feedback period of the channel information by using the sounding signal or the reference signal.

In the above scheme, the data transmission is multipath propagation;

correspondingly, for each propagation path, periodically feeding back corresponding channel information to the sending end device.

In the scheme, the high-frequency transmission is downlink high-frequency transmission;

accordingly, the channel information is periodically transmitted through the low frequency uplink.

The embodiment of the invention provides a channel information indicating method, which comprises the following steps:

sending a detection signal or a reference signal to receiving end equipment by sending end equipment;

the receiving end equipment responds to the detection signal or the reference signal and periodically feeds back first information and second information to the sending end equipment; the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading;

the sending end equipment obtains channel information according to the first information and the second information; wherein the content of the first and second substances,

In the above scheme, the obtaining channel information according to the first information and the second information includes:

the first information and the second information are information in a time domain, and the sending end equipment convolves the first information and the second information to obtain the channel information; alternatively, the first and second electrodes may be,

the first information and the second information are information on a frequency domain, and the sending equipment multiplies the first information and the second information to obtain the channel information.

In the foregoing solution, when the first information and the second information are periodically fed back to the sending-end device, the method further includes:

periodically feeding back third information to the sending end equipment; the third information characterizes channel response caused by other factors except frequency offset and frequency spreading; the feedback period of the third information is a third period; the second period is greater than the third period;

correspondingly, the sending end device obtains the channel information according to the first information, the second information and the third information.

In the above scheme, obtaining the channel information according to the first information, the second information, and the third information includes:

the first information, the second information and the third information are information in a time domain, and the sending end equipment convolves the first information, the second information and the third information to obtain the channel information; alternatively, the first and second electrodes may be,

the first information, the second information and the third information are information on a frequency domain, and the sending equipment multiplies the first information, the second information and the third information to obtain the channel information.

An embodiment of the present invention further provides a receiving end device, including: a receiving unit and a transmitting unit; wherein the content of the first and second substances,

the receiving unit is used for receiving a detection signal or a reference signal sent by sending end equipment;

the sending unit is configured to periodically feed back first information and second information to the sending end device in response to the detection signal or the reference signal; the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading; wherein the content of the first and second substances,

In the foregoing solution, the sending unit is further configured to periodically feed back third information to the sending end device, where the third information represents a channel response caused by other factors except frequency offset and frequency spreading;

In the above solution, the apparatus further includes: an acquisition unit and an extraction unit; wherein the content of the first and second substances,

the acquisition unit is configured to acquire channel information using the sounding signal or the reference signal;

the extracting unit is configured to extract the first information, the second information, and the third information from the obtained channel information.

In the above solution, the apparatus further includes: and the determining unit is used for determining the feedback period of the channel information by using the detection signal or the reference signal.

correspondingly, the sending unit is specifically further configured to: and periodically transmitting the channel information through the low-frequency uplink.

The embodiment of the present invention further provides a channel information indicating system, including: a sending terminal device and a receiving terminal device; wherein the content of the first and second substances,

the sending end equipment is used for sending a detection signal or a reference signal to the receiving end equipment; after receiving the first information and the second information, obtaining channel information according to the first information and the second information;

the receiving end equipment is used for responding to the detection signal or the reference signal and periodically feeding back first information and second information to the sending end equipment; the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading;

In the above scheme, the receiving end device is further configured to periodically feed back third information to the sending end device when periodically feeding back the first information and the second information to the sending end device; the third information characterizes channel response caused by other factors except frequency offset and frequency spreading; the feedback period of the third information is a third period; the second period is greater than the third period;

correspondingly, the sending end device is further configured to obtain the channel information according to the first information, the second information, and the third information after receiving the third information.

In the channel information indication method, system and receiving end device provided by the embodiment of the invention, the receiving end device receives the detection signal or the reference signal sent by the sending end device; responding to the detection signal or the reference signal, and periodically feeding back first information and second information to the sending end equipment; the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading; the sending period of the first information is a first period; the sending period of the second information is a second period; the first period is greater than the second period, and because the channel response caused by the doppler frequency shift and the frequency shift spread belongs to a slow-changing process, and the change of the channel response caused by the frequency shift is faster than the change degree of the channel response caused by the doppler frequency shift, the two pieces of information can be fed back slowly (periodically) (the feedback period of the frequency shift is less than the feedback period of the doppler frequency shift), so that the frequency and the information amount fed back by the receiving end device to the channel information are reduced.

Drawings

In the drawings, which are not necessarily drawn to scale, like reference numerals may describe similar components in different views. Like reference numerals having different letter suffixes may represent different examples of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed herein.

FIG. 1 is a diagram illustrating a frequency domain shift comparison between a high frequency signal and a low frequency signal in the related art;

fig. 2 is a schematic flow chart of a channel information indication method at a receiving end device side according to an embodiment of the present invention;

FIG. 3 is a diagram illustrating frequency offset and frequency spreading at high frequency in the related art;

FIG. 4 is a flowchart illustrating a channel information indication method according to an embodiment of the present invention;

FIG. 5 is a flowchart illustrating a second channel information indication method according to an embodiment of the present invention;

FIG. 6 is a flowchart illustrating a method for indicating three-channel information according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a four-receiver device according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a four-channel information indication system according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Before describing embodiments of the present invention, a related art will be understood.

First, at present, channel information fed back to a sending end device by a receiving end device mainly includes: reference Signal Received Power (RSRP), Reference Signal Receiving Quality (RSRQ), Channel Quality Information (CQI), and Channel State Information (CSI), which only reflect the State Information of the Channel but do not show the specific Information such as frequency offset.

Therefore, after receiving the information, the sending end device obtains the specific channel information including the frequency offset and the like through a channel estimation mode.

However, when the mobile communication system operates at a high frequency, a large doppler effect is encountered. Equation (1) shows the frequency shift caused by the doppler effect as a function of the relevant parameter.

Wherein f is_carrierThe frequency of the carrier wave, c the speed of light, v the moving speed and theta the included angle between the moving direction of the terminal and the incident wave direction.

It can be seen from the formula (1) that, in a high-frequency channel, for example, in a frequency band of 30GHz to 300GHz, since the propagation of electromagnetic waves is more sensitive to the moving speed and is more easily affected by the doppler effect, the doppler frequency offset of the high frequency is more serious.

In addition, in the future, high frequency is applied to a radio access network, and due to different positions of receiving ends, a propagation path has certain uncertainty. The magnitude of the frequency offset generated by the doppler effect is related to the incident angle of the receiving end, so that the frequency offset generated by the doppler effect has certain uncertainty.

In this case, according to the existing channel estimation method, the communication system needs to frequently detect and estimate the channel, so as to ensure that correct channel information is obtained, and thus, the amount of transmitted information is greatly increased.

Secondly, since the high frequency signal is more particulate and has a shorter wavelength, it exhibits a reflection rather than scattering characteristic on most surfaces, which results in a relatively small frequency spread for a single path, as shown in fig. 1, although the frequency shift due to the doppler effect is relatively large compared to the low frequency signal. In fig. 1, the abscissa represents the frequency domain and the ordinate represents the power.

Based on this, in various embodiments of the invention: receiving end equipment receives a detection signal or a reference signal sent by sending end equipment; responding to the detection signal or the reference signal, and periodically feeding back first information and second information to the sending end equipment; the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading; the sending period of the first information is a first period; the sending period of the second information is a second period; the first period is greater than the second period.

The application scenarios of the embodiment of the present invention may be as follows: the working frequency of the mobile communication system is high frequency, and in practical application, the high frequency is greater than or equal to 6 GHz.

Example one

The channel information indication method of this embodiment is applied to a receiving end device, as shown in fig. 2, the method includes the following steps:

step 201: receiving a detection signal or a reference signal sent by sending end equipment;

step 202: and responding to the detection signal or the reference signal, and periodically feeding back the first information and the second information to the sending end equipment.

Here, the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading.

At this time, the channel information fed back to the sending end device includes: the first information and the second information.

In practical application, the channel information that changes rapidly in the time domain can be converted into the frequency domain, and then the following formula is obtained:

H_{f_domain}＝H_{f_domain}(f_shift)×H_{f_domain}(f_spread)×H_other(2)

wherein H_{f_domain}Representing the overall impulse response of the channel; h_{f_domain}(f_shift) Indicating a channel response in a channel due to a frequency offset, i.e., first information; h_{f_domain}(f_spread) A frequency offset part representing a frequency of the multipath channel due to a sub-path fluctuation within each cluster (cluster), that is, a frequency spread of each cluster, thereby an impulse response of the corresponding channel, that is, second information; h_otherRepresenting the channel response due to factors other than doppler shift correlation, and × representing frequency domain multiplication.

Equivalently, the three parameters in the formula (2) can also be convolved in the time domain, and finally the response of the channel is obtained.

In addition, fig. 3 shows a schematic diagram of frequency offset and frequency spreading at high frequencies. As can be seen from fig. 3, the doppler frequency shift (H) is compared to the overall channel variation_{f_domain}(f_shift) And frequency shift spreading (H)_{f_domain}(f_spread) And the channel response caused by the frequency spreading is faster than the change degree of the channel response caused by the doppler frequency offset, it is possible to reduce the feedback amount of the channel information by feeding back both information slowly (periodically) (the feedback period of the frequency spreading is shorter than the feedback period of the doppler frequency offset). And H_otherAlthough the change is fast, the proportion of the information of the whole channel is small, so that the feedback can be avoided according to the actual situation. That is, only the first information and the second information are fed back. In fig. 3, the abscissa represents the frequency domain and the ordinate represents the power.

In an embodiment, when the first information and the second information are fed back to the sending end device periodically, the method may further include:

periodically feeding back third information to the sending end equipment; the third information characterizes channel response caused by other factors except frequency offset and frequency spreading;

At this time, the channel information fed back to the sending end device includes: the first information, the second information and the third information.

Here, in practical application, before periodically feeding back channel information to the sending end device, the method may further include:

In practical applications, the first period, the second period, and the third period may be: the setting is performed in advance as required. The receiving end device may determine a feedback period of each piece of information according to the received sounding signal or reference signal.

Based on this, in an embodiment, before periodically feeding back channel information to the sending end device, the method may further include:

and the receiving end equipment determines the feedback period of the channel information by using the detection signal or the reference signal.

For example, in practical applications, when the first information (frequency offset) does not change much, it indicates that the receiving end is moving at a low speed or is stationary, or there are few scatterers moving in the surrounding environment, which indicates that frequent frequency offset feedback is not needed. Therefore, the receiving end device can reduce the updating period of the first information. Otherwise, a larger update period is required. For example, in a relatively static environment, the receiving end device may feed back the first information once every 10 times of feeding back the second information; in a dynamic or mobile environment, the receiving-end device may feed back the first information once every 2 times the second information is fed back.

In practical applications, when the operating frequency of the mobile communication system is high frequency (for example, above 6GHz), the multipath propagation path is less than the low frequency when the mobile communication system operates at the low frequency, and thus the phenomenon is shown as follows: the number of the multi-path sets after clustering is reduced from 12-20 low frequencies to 3-4, and further the total amount of channel information required to be acquired is reduced. Channel information can thus be fed back for each propagation path.

Based on this, in one embodiment, the transmission of data is multipath propagation;

Wherein, the receiving end device may obtain the channel information of each propagation path in advance.

In practical application, because the requirement of high-frequency transmission on hardware is high, and the complexity of implementation at a terminal is also relatively high, the scenario for deploying high-frequency transmission may be: there is only downlink high frequency transmission. At this time, the receiving end device needs to feed back the channel information through low frequency (frequency less than 6GHz) transmission.

Based on this, in an embodiment, the sending end device is a base station, the receiving end device is a terminal, and high-frequency (frequency greater than or equal to 6GHz) transmission is downlink high-frequency transmission;

that is, the sending end device sends a probe signal or a reference signal to the receiving end device at a high frequency, and further sends data to the receiving end device at a high frequency;

correspondingly, the receiving end equipment periodically transmits the channel information through the low-frequency uplink.

The present embodiment further provides a channel information indication method, as shown in fig. 4, the method includes the following steps:

step 401: sending a detection signal or a reference signal to receiving end equipment by sending end equipment;

step 402: the receiving end equipment responds to the detection signal or the reference signal and periodically feeds back first information and second information to the sending end equipment;

In practical application, the channel information that changes rapidly in the time domain can be converted into the frequency domain, and then equation (2) is obtained.

H_{f_domain}＝H_{f_domain}(f_shift)×H_{f_domain}(f_spread)×H_other(2)

In the formula (2), H_{f_domain}Representing the overall impulse response of the channel, namely the channel information on the time domain needing to be fed back; h_{f_domain}(f_shift) Indicating a channel response in a channel due to a frequency offset, i.e., first information; h_{f_domain}(f_spread) A frequency offset part representing a frequency of the multipath channel due to a sub-path fluctuation within each cluster (cluster), that is, a frequency spread of each cluster, thereby an impulse response of the corresponding channel, that is, second information; h_otherRepresenting the channel response due to factors other than doppler shift correlation, and × representing frequency domain multiplication.

In addition, fig. 3 shows a schematic diagram of frequency offset and frequency spreading at high frequencies. As can be seen from fig. 3, the doppler frequency shift (H) is compared to the overall channel variation_{f_domain}(f_shift) And frequency shift spreading (H)_{f_domain}(f_spread) The channel response caused by the frequency spreading is a slowly varying process, and the variation of the channel response caused by the frequency spreading is faster than the variation of the channel response caused by the doppler frequency offset, so that the feedback amount of the channel information can be reduced by slowly (periodically) feeding back the two information (the feedback period of the frequency spreading is shorter than that of the doppler frequency offset). And H_otherAlthough the change is fast, the proportion of the information of the whole channel is small, so that the feedback can be avoided according to the actual situation. That is, only the first information and the second information are fed back. In fig. 3, the abscissa represents the frequency domain and the ordinate represents the power.

that is, the sending-end device sends a probe signal or a reference signal to the receiving-end device only at high frequency, and further sends data to the receiving-end device only at high frequency;

Step 403: and the sending end equipment obtains channel information according to the first information and the second information.

Here, specifically, when the first information and the second information are information in a frequency domain, the sending end device multiplies the first information and the second information to obtain the channel information, and the channel information is expressed by a formula, where the formula includes:

H_{f_domain}＝H_{f_domain}(f_shift)×H_{f_domain}(f_spread) (3)

wherein H_{f_domain}Representing the overall impulse response of the channel, namely the channel information on the time domain needing to be fed back; h_{f_domain}(f_shift) Indicating a channel response in a channel due to a frequency offset, i.e., first information; h_{f_domain}(f_spread) Representing the offset part of the frequency of the multipath channel due to the fluctuation of the sub-paths within each cluster, i.e. the frequency spread of each cluster, and thus the impulse response of the corresponding channel, i.e. the second information, × represents the frequency domain multiplication.

And when the first information and the second information are information in a time domain, the sending equipment convolves the first information and the second information to obtain the channel information.

Here, when the receiving end device sends first information, second information, and third information to the sending end device, the sending end device obtains the channel information according to the first information, the second information, and the third information.

At this time, when the first information, the second information, and the third information are information on a frequency domain, the channel information is obtained by multiplying the first information, the second information, and the third information, and when the channel information is expressed by a formula, formula (2) is obtained.

And when the first information, the second information and the third information are information in a time domain, the sending equipment convolutes the first information, the second information and the third information to obtain the channel information.

In practical application, the high-frequency transmission needs to perform precoding training on data transmission and reception according to the positions of the terminal and the base station. Because the sending end device and the receiving end device may adopt respective training modes, two sets of completely different transmission codes may be adopted for uplink and downlink transmission of the base station and the terminal, which results in poor channel reciprocity and difficult use. After the sending end equipment obtains the channel information, the obtained channel information is used for adjusting the transmission codes, namely the obtained channel information is used for participating in the pre-coding of the data, and the adjustment work before the data is sent is carried out, so that the transmission efficiency is improved.

In the channel information indication method provided by the embodiment of the invention, receiving end equipment receives a detection signal or a reference signal sent by sending end equipment; responding to the detection signal or the reference signal, and periodically feeding back first information and second information to the sending end equipment; the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading; the sending period of the first information is a first period; the sending period of the second information is a second period; the first period is greater than the second period, and because the channel response caused by the doppler frequency shift and the frequency shift spread belongs to a slow-changing process, and the change of the channel response caused by the frequency shift is faster than the change degree of the channel response caused by the doppler frequency shift, the two pieces of information can be fed back slowly (periodically) (the feedback period of the frequency shift is less than the feedback period of the doppler frequency shift), so that the frequency and the information amount fed back by the receiving end device to the channel information are reduced.

In addition, the transmission of data is multipath propagation; correspondingly, for each propagation path, the corresponding channel information is fed back to the sending end device periodically, so that the sending end device can conveniently select the channel.

Example two

In this embodiment, on the basis of the first embodiment, how to perform the indicating process of the channel information is described in detail.

The application scenario of this embodiment is as follows: the sending end equipment is a base station, and the receiving end equipment is a terminal. In this embodiment, the feedback information is information in a frequency domain.

The method for indicating channel information in this embodiment, as shown in fig. 5, mainly includes the following steps:

step 501: a base station sends a detection signal/a reference signal to a terminal;

step 502: after receiving the detection signal/reference signal, the terminal obtains channel information by using the received detection signal/reference signal; dividing channel information;

specifically, the channel information is divided into: frequency offset induced channel response H1 (H)_{f_domain}(f_shift) H2 (H) channel response due to frequency spreading_{f_domain}(f_spread) H3 (H), and other factors caused channel response_other) And (4) three parts of information.

Step 503: the terminal feeds back three information of H1, H2 and H3 to the base station;

step 504: after receiving the three information, the base station calculates the product of the three information to obtain corresponding channel information, and adjusts the transmission code by using the obtained channel information;

step 505: the base station sends a detection signal/reference signal and data to the terminal for the first time;

step 506: after receiving the detection signal/reference signal and the data, the terminal obtains channel information by utilizing the received detection signal/reference signal; dividing channel information;

Step 507: the terminal feeds back the obtained H2 and H3 information to the base station;

step 508: after receiving the two pieces of information, the base station performs convolution on the two pieces of information and the H1 obtained before to obtain corresponding channel information, and adjusts transmission codes by using the obtained channel information;

step 509: the base station sends the detection signal/reference signal and data to the terminal for the second time;

step 510: after receiving the detection signal/reference signal and the data, the terminal obtains channel information by utilizing the received detection signal/reference signal; dividing channel information;

Step 511: and the terminal feeds back the obtained H2 and H3 information to the base station according to the respective feedback periods of H1, H2 and H3, and so on.

Wherein, assuming that feedback periods corresponding to H1, H2 and H3 are T1, T2 and T3, respectively, there are T1 > T2 > T3.

Here, since H1 is strongly correlated with the direction of propagation, its feedback period is longest; h2 is the fluctuation of the sub-path within each propagation path, the fluctuation is large, and therefore the update is relatively fast; h3 is the channel response caused by factors other than the factors corresponding to H1 and H2, in other words, H3 is the residue of the channel response that is not characterized by H1 and H2.

Here, since H3 has a small weight in the entire channel information, H3 may not be fed back as necessary in practical use.

EXAMPLE III

In this embodiment, how to perform the indicating process of the channel information is detailed based on the first embodiment.

The application scenario of this embodiment is as follows: the sending end equipment is a base station, and the receiving end equipment is a terminal. There is only downlink high frequency transmission. In this embodiment, the feedback information is information in a frequency domain.

In this case, it is necessary to perform matching between high-frequency transmission and low-frequency transmission when channel information feedback is performed. The procedure of the channel information indication in this embodiment, as shown in fig. 6, includes the following steps:

step 601: a base station sends a data signal and a reference signal/detection signal to a terminal through high frequency;

step 602: after the terminal receives the signal, the parameter is utilizedObtains channel information by referring to the signal/sounding signal, and extracts H1 (H)_{f_domain}(f_shift))、H2(H_{f_domain}(f_spread))、H3(H_other) Three parts;

step 603: the terminal feeds back three information of H1, H2 and H3 to the base station at different periods on low frequency;

the feedback period of H1 is longest, and the feedback period of H2 is shorter; the feedback period of H3 is the shortest, or H3 may not be fed back.

Step 604: and the base station updates the downlink transmission codes according to the information H1, H2 and H3 fed back by the terminal on the low frequency.

Specifically, H1, H2, and H3 are multiplied to obtain channel information, and the downlink transmission code is updated by using the channel information.

Example four

To implement the method according to the embodiment of the present invention, this embodiment provides a receiving end device, as shown in fig. 7, where the receiving end device includes: a receiving unit 71 and a transmitting unit 72; wherein the content of the first and second substances,

the receiving unit 71 is configured to receive a probe signal or a reference signal sent by a sending end device;

the sending unit 72 is configured to respond to the probe signal or the reference signal, and periodically feed back the first information and the second information to the sending-end device; the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading; wherein the content of the first and second substances,

In this case, the channel information fed back by the sending unit 72 to the sending end device includes: the first information and the second information.

H_{f_domain}＝H_{f_domain}(f_shift)×H_{f_domain}(f_spread)×H_other(2)

wherein H_{f_domain}Representing the overall impulse response of the channel, namely the channel information on the time domain needing to be fed back; h_{f_domain}(f_shift) Indicating a channel response in a channel due to a frequency offset, i.e., first information; h_{f_domain}(f_spread) A frequency offset part representing a frequency of the multipath channel due to a sub-path fluctuation within each cluster (cluster), that is, a frequency spread of each cluster, thereby an impulse response of the corresponding channel, that is, second information; h_otherIndicating the channel response due to factors other than doppler phase correlation, × indicating the frequency domain phase.

In addition, fig. 3 shows a schematic diagram of frequency offset and frequency spreading at high frequencies. As can be seen from fig. 3, the doppler frequency shift (H) is compared to the overall channel variation_{f_domain}(f_shift) And frequency shift spreading (H)_{f_domain}(f_spread) And the channel response caused by the frequency spreading is faster than the change degree of the channel response caused by the doppler frequency offset, it is possible to reduce the feedback amount of the channel information by feeding back both information slowly (periodically) (the feedback period of the frequency spreading is shorter than the feedback period of the doppler frequency offset). And H_otherAlthough the change is fast, the proportion of the information of the whole channel is small, so that the feedback can be avoided according to the actual situation. That is, the sending unit 72 feeds back only the first information and the second information. In fig. 3, the abscissa represents the frequency domain and the ordinate represents the power.

In an embodiment, the sending unit 72 is further configured to periodically feed back third information to the sending-end device, where the third information represents a channel response caused by other factors except frequency offset and frequency spreading;

In this case, the channel information fed back by the sending unit 72 to the sending end device includes: the first information, the second information and the third information.

Here, in practical application, the apparatus may further include: an acquisition unit and an extraction unit; wherein the content of the first and second substances,

Based on this, in an embodiment, the apparatus may further include: and the determining unit is used for determining the feedback period of the channel information by using the detection signal or the reference signal.

For example, in practical applications, when the first information (frequency offset) does not change much, it indicates that the receiving end is moving at a low speed or is stationary, or there are few scatterers moving in the surrounding environment, which indicates that frequent frequency offset feedback is not needed. The determination unit may reduce the update period of the first information. Otherwise, a larger update period is required. For example, in a relatively static environment, the determination unit may determine to feed back the first information once every 10 times of feeding back the second information; in a dynamic or mobile environment, the determination unit determines that the first information can be fed back once every 2 times the second information is fed back.

In practical applications, when the operating frequency of the mobile communication system is a high frequency (e.g. 30 GHz-300 GHz), the multipath propagation path is less than the low frequency when the mobile communication system operates at the low frequency, and thus the phenomenon is shown as follows: the number of the multi-path sets after clustering is reduced from 12-20 low frequencies to 3-4, and further the total amount of channel information required to be acquired is reduced. Channel information can thus be fed back for each propagation path.

accordingly, the sending unit 72 is configured to periodically feed back corresponding channel information to the sending end device for each propagation path.

correspondingly, the sending unit 72 is further specifically configured to: and periodically transmitting the channel information through the low-frequency uplink.

In practical application, the receiving unit 71 and the sending unit 72 may be implemented by a transceiver in a receiving end device; the obtaining Unit, the extracting Unit and the determining Unit may be implemented by a Central Processing Unit (CPU), a Microprocessor (MCU), a Digital Signal Processor (DSP), or a Programmable logic Array (FPGA) in the receiving end device.

In order to implement the method according to the embodiment of the present invention, this embodiment further provides a channel information indication system, as shown in fig. 8, where the system includes: a transmitting side device 81 and a receiving side device 82; wherein the content of the first and second substances,

the sending end device 81 is configured to send a probe signal or a reference signal to the receiving end device 82; after receiving the first information and the second information, obtaining channel information according to the first information and the second information;

the receiving end device 82 is configured to respond to the probe signal or the reference signal and periodically feed back the first information and the second information to the sending end device 81; the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading;

In this case, the channel information fed back to the transmitting device 81 includes: the first information and the second information.

H_{f_domain}＝H_{f_domain}(f_shift)×H_{f_domain}(f_spread)×H_other(2)

In the formula (2), H_{f_domain}Representing the overall impulse response of the channel, namely the channel information on the time domain needing to be fed back; h_{f_domain}(f_shift)H(f_shift) Indicating a channel response in a channel due to a frequency offset, i.e., first information; h_{f_domain}(f_spread) A frequency offset part representing a frequency of the multipath channel due to a sub-path fluctuation within each cluster (cluster), that is, a frequency spread of each cluster, thereby an impulse response of the corresponding channel, that is, second information; h_otherRepresenting the channel response due to factors other than doppler shift correlation, and × representing frequency domain multiplication.

In addition, fig. 3 shows a schematic diagram of frequency offset and frequency spreading at high frequencies. As can be seen from fig. 3, the doppler frequency shift (H) is compared to the overall channel variation_{f_domain}(f_shift) And frequency shift spreading (H)_{f_domain}(f_spread) Caused by)The channel response belongs to a slowly varying process, and the channel response variation caused by the frequency spreading is faster than the variation degree of the channel response caused by the doppler frequency offset, so that the feedback amount of the channel information can be reduced by slowly (periodically) feeding back the two information (the feedback period of the frequency spreading is shorter than that of the doppler frequency offset). And H_otherAlthough the change is fast, the proportion of the information of the whole channel is small, so that the feedback can be avoided according to the actual situation. That is, only the first information and the second information are fed back. In fig. 3, the abscissa represents the frequency domain and the ordinate represents the power.

In an embodiment, the receiving end device 82 is further configured to periodically feed back third information to the sending end device 81 when periodically feeding back the first information and the second information to the sending end device 81; the third information characterizes channel response caused by other factors except frequency offset and frequency spreading; the feedback period of the third information is a third period; the second period is greater than the third period;

correspondingly, the sending-end device 81 is further configured to obtain the channel information according to the first information, the second information, and the third information after receiving the third information.

Here, in practical application, before periodically feeding back channel information to the sending end device 81, the receiving end device 82 is further configured to obtain channel information by using the probe signal or the reference signal; and extracting the first information, the second information and the third information from the obtained channel information.

Based on this, in an embodiment, before feeding back the channel information to the sending end device 81 periodically, the receiving end device 82 is further configured to determine a feedback period of the channel information by using the sounding signal or the reference signal.

For example, in practical applications, when the first information (frequency offset) does not change much, it indicates that the receiving end is moving at a low speed or is stationary, or there are few scatterers moving in the surrounding environment, which indicates that frequent frequency offset feedback is not needed. Therefore, the receiving end device can reduce the updating period of the first information. Otherwise, a larger update period is required. For example, in a relatively static environment, the receiving-end device 82 may feed back the first information every time the second information is fed back 10 times; in a dynamic or mobile environment, the receiving-end device 82 may feed back the first information once every 2 times the second information is fed back.

accordingly, for each propagation path, the receiving end device 82 periodically feeds back corresponding channel information to the transmitting end device.

Wherein, the receiving end device 82 may obtain the channel information of each propagation path in advance.

that is, the transmitting-end device 81 transmits a probe signal or a reference signal to the receiving-end device 82 only at a high frequency, and further transmits data to the receiving-end device 82 only at a high frequency;

accordingly, the receiving end device 82 periodically transmits channel information through a low frequency uplink.

When the first information and the second information are information in the frequency domain, the sending end device 81 obtains channel information by taking the product (product) of the first information and the second information, and the channel information is expressed by a formula, which includes:

H_{f_domain}＝H_{f_domain}(f_shift)×H_{f_domain}(f_spread) (3)

When the first information and the second information are information in a time domain, the sending device 81 convolves the first information and the second information to obtain the channel information.

Here, when the receiving side device 82 transmits the first information, the second information, and the third information to the transmitting side device 81, the transmitting side device 81 obtains the channel information based on the first information, the second information, and the third information.

At this time, when the first information, the second information, and the third information are information on a frequency domain, the first information, the second information, and the third information are multiplied to obtain the channel information, and when the channel information is expressed by a formula, a formula (2) is obtained.

According to the scheme provided by the embodiment of the invention, the receiving end equipment receives the detection signal or the reference signal sent by the sending end equipment; responding to the detection signal or the reference signal, and periodically feeding back first information and second information to the sending end equipment; the first information characterizes a channel response caused by a frequency offset; the second information characterizes a channel response caused by frequency spreading; the sending period of the first information is a first period; the sending period of the second information is a second period; the first period is greater than the second period, and because the channel response caused by the doppler frequency shift and the frequency shift spread belongs to a slow-changing process, and the change of the channel response caused by the frequency shift is faster than the change degree of the channel response caused by the doppler frequency shift, the two pieces of information can be fed back slowly (periodically) (the feedback period of the frequency shift is less than the feedback period of the doppler frequency shift), so that the frequency and the information amount fed back by the receiving end device to the channel information are reduced.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Claims

1. A channel information indication method is applied to a receiving end device, and the method comprises the following steps:

2. The method of claim 1, wherein when the first information and the second information are fed back to the sending end device periodically, the method further comprises: periodically feeding back third information to the sending end equipment; the third information characterizes channel response caused by other factors except frequency offset and frequency spreading;

3. The method of claim 2, wherein before periodically feeding back channel information to the transmitting device, the method further comprises:

4. The method of claim 1, further comprising:

5. The method according to any one of claims 1 to 4, wherein the transmission of data is multipath propagation;

6. The method according to any one of claims 1 to 4, wherein the high frequency transmission is a downlink high frequency transmission;

7. A method for indicating channel information, the method comprising:

8. The method of claim 7, wherein the obtaining channel information according to the first information and the second information comprises:

the first information and the second information are information on a frequency domain, and the sending end equipment multiplies the first information and the second information to obtain the channel information.

9. The method of claim 7, wherein when the first information and the second information are fed back to the sending end device periodically, the method further comprises:

10. The method of claim 9, wherein obtaining the channel information according to the first information, the second information, and the third information comprises:

the first information, the second information and the third information are information in a frequency domain, and the sending end equipment multiplies the first information, the second information and the third information to obtain the channel information.

11. A receiving-end device, characterized in that the device comprises: a receiving unit and a transmitting unit; wherein the content of the first and second substances,

12. The apparatus according to claim 11, wherein the sending unit is further configured to periodically feed back third information to the sending-end apparatus, where the third information characterizes a channel response caused by other factors besides frequency offset and frequency spreading;

13. The apparatus of claim 12, further comprising: an acquisition unit and an extraction unit; wherein the content of the first and second substances,

14. The apparatus of claim 11, further comprising: and the determining unit is used for determining the feedback period of the channel information by using the detection signal or the reference signal.

15. The apparatus according to any one of claims 11 to 14, wherein the high frequency transmission is a downlink high frequency transmission;

16. A channel information indication system, the system comprising: a sending terminal device and a receiving terminal device; wherein the content of the first and second substances,

17. The system according to claim 16, wherein the receiving end device is further configured to periodically feed back third information to the sending end device when the first information and the second information are periodically fed back to the sending end device; the third information characterizes channel response caused by other factors except frequency offset and frequency spreading; the feedback period of the third information is a third period; the second period is greater than the third period;