CN107094042B - Channel information indication method, system and receiver device - Google Patents

Abstract

The invention discloses a channel information indication method, comprising: a receiving end device receives a sounding signal or a reference signal sent by a transmitting end device; in response to the sounding signal or the reference signal, periodically feeding back first information and a reference signal to the transmitting end device second information; the first information represents the frequency offset of the channel; the second information represents the frequency extension of the channel; wherein, the transmission period of the first information is the first period; The transmission period is the 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 receiver device

technical field

The present invention relates to the field of wireless communication, and in particular, to a channel information indication method, system and receiver device.

Background technique

The mobile communication system will encounter a large Doppler effect at high frequencies, which will cause a large frequency offset to the channel. For high-frequency communications (such as 30 GHz to 300 GHz), such a frequency offset will be more significant.

On the other hand, high frequency will be applied to wireless access network in the future. Due to the different positions of the receiving end, the propagation path has certain uncertainty. However, the size of the frequency offset generated by the Doppler effect is related to the incident angle of the receiving end, so the frequency offset generated by the Doppler effect has a certain uncertainty.

It is precisely because the frequency offset generated by the Doppler effect can cause the channel to change rapidly, so according to the existing channel estimation methods, the communication system needs to frequently detect and estimate the channel, so as to ensure that the correct channel information can be obtained. Increase the amount of information transmitted.

SUMMARY OF THE INVENTION

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

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

An embodiment of the present invention provides a channel information indication method, which is applied to a receiving end device, and the method includes:

Receive the sounding signal or reference signal sent by the transmitting end device;

In response to the sounding signal or the reference signal, the first information and the second information are periodically fed back to the transmitting end device; the first information represents the channel response caused by frequency offset; the second information represents the frequency expansion caused by channel response; where,

The transmission period of the first information is the first period; the transmission period of the second information is the second period; the first period is greater than the second period.

In the above solution, when periodically feeding back the first information and the second information to the transmitting end device, the method further includes: periodically feeding back third information to the transmitting end device; the third information represents the frequency offset channel response caused by factors other than frequency shift and frequency spread;

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

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

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

The first information, the second information and the third information are extracted from the obtained channel information.

In the above scheme, the method also includes:

Using the sounding signal or the reference signal, the feedback period of the channel information is determined.

In the above scheme, the transmission of data is multi-path propagation;

Correspondingly, for each propagation path, the corresponding channel information is periodically fed back to the transmitting end device.

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

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

An embodiment of the present invention provides a channel information indication method, including:

The transmitting end device sends a sounding signal or a reference signal to the receiving end device;

The receiving end device periodically feeds back first information and second information to the transmitting end device in response to the sounding signal or the reference signal; the first information represents a channel response caused by a frequency offset; the second information Characterize the channel response due to frequency spreading;

The transmitting end device obtains channel information according to the first information and the second information; wherein,

The transmission period of the first information is the first period; the transmission period of the second information is the second period; the first period is greater than the second period.

In the above solution, the channel information obtained according to the first information and the second information is:

The first information and the second information are information in the time domain, and the transmitting end device convolves the first information and the second information to obtain the channel information; or,

The first information and the second information are information in the frequency domain, and the sending device multiplies the first information and the second information to obtain the channel information.

In the above solution, when periodically feeding back the first information and the second information to the transmitting end device, the method further includes:

Periodically feed back third information to the transmitting end device; the third information represents the channel response caused by factors other than frequency offset and frequency extension; the feedback period of the third information is the third period; the The second period is greater than the third period;

Correspondingly, the transmitting end device obtains the channel information according to the first information, the second information and the third information.

In the above solution, the channel information obtained according to the first information, the second information and the third information is:

The first information, the second information and the third information are information in the time domain, and the transmitting end device convolves the first information, the second information and the third information to obtain the channel information; or,

The first information, the second information and the third information are information in the frequency domain, and the transmitting device obtains the channel information by multiplying the first information, the second information and the third information.

An embodiment of the present invention further provides a receiving end device, including: a receiving unit and a sending unit; wherein,

The receiving unit is configured to receive a sounding signal or a reference signal sent by the transmitting end device;

The sending unit is configured to periodically feed back first information and second information to the sending end device in response to the sounding signal or the reference signal; the first information represents a channel response caused by a frequency offset; the The second information characterizes the channel response due to frequency spreading; wherein,

The transmission period of the first information is the first period; the transmission period of the second information is the second period; the first period is greater than the second period.

In the above solution, the sending unit is further configured to periodically feed back third information to the sending end device. The third information represents the channel response caused by other factors except frequency offset and frequency extension;

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

In the above solution, the device further includes: an acquisition unit and an extraction unit; wherein,

the obtaining unit, configured to obtain channel information by using the sounding signal or the reference signal;

The extraction 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 device further includes: a determining unit configured to determine the feedback period of the channel information by using the sounding signal or the reference signal.

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

Correspondingly, the sending unit is further configured to: periodically transmit the channel information through the low frequency uplink.

An embodiment of the present invention further provides a channel information indication system, including: a sending end device and a receiving end device; wherein,

The transmitting end device is configured to send a sounding signal or a reference signal to the receiving end device; and after receiving the first information and the second information, obtain channel information according to the first information and the second information;

The receiving end device is configured to periodically feed back first information and second information to the transmitting end device in response to the sounding signal or the reference signal; the first information represents a channel response caused by a frequency offset; the The second information characterizes the channel response caused by frequency spreading;

The transmission period of the first information is the first period; the transmission period of the second information is the second period; the first period is greater than the second period.

In the above solution, the receiving end device is further configured to periodically feed back third information to the transmitting end device when periodically feeding back the first information and the second information to the transmitting end device; the third information represents the The channel response caused by other factors except frequency offset and frequency extension; the feedback period of the third information is the third period; the second period is greater than the third period;

Correspondingly, the transmitting 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 embodiments of the present invention, the receiving end device receives a sounding signal or a reference signal sent by a transmitting end device, and periodically feeds back to the transmitting end device in response to the sounding signal or reference signal first information and second information; the first information represents the channel response caused by frequency offset; the second information represents the channel response caused by frequency extension; wherein, the transmission period of the first information is the first period; The transmission period of the second information is the second period; the first period is greater than the second period, and the channel response caused by the Doppler frequency offset and the shift frequency spread is a slow-changing process, and the frequency spread causes The change of the channel response is faster than the change of the channel response caused by the Doppler frequency offset, so the two information can be fed back slowly (periodically) (the feedback period of the frequency extension is smaller than the feedback of the Doppler frequency offset cycle), in this way, the frequency and amount of information fed back by the receiving end device to the channel information are reduced.

Description of drawings

In the drawings, which are not necessarily to scale, like reference numerals may describe like parts in the different views. Similar reference numbers with different letter suffixes may denote different instances of similar components. The accompanying drawings generally illustrate, by way of example and not limitation, the various embodiments discussed herein.

FIG. 1 is a schematic diagram of the frequency domain offset comparison between a high-frequency signal and a low-frequency signal in the related art;

FIG. 2 is a schematic flowchart of a method for indicating channel information on the receiving end device side according to Embodiment 1 of the present invention;

3 is a schematic diagram of frequency offset and frequency expansion at high frequencies in the related art;

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

5 is a schematic flowchart of a method for indicating channel information according to Embodiment 2 of the present invention;

FIG. 6 is a schematic flowchart of a third channel information indication method according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a receiving end device according to Embodiment 4 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 ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Before describing the embodiments of the present invention, let us first understand the related technologies.

First, at present, the channel information fed back by the receiving end device to the transmitting end device mainly includes: Reference Signal Receiving Power (RSRP, Reference Signal Receiving Power), Reference Signal Receiving Quality (RSRQ, Reference Signal Receiving Quality), Channel Quality Information (CQI, Channel Quality Indicator), and Channel State Information (CSI, Channel State Information), and these information only reflect the state information of the channel, but specific information such as frequency offset will not be displayed and characterized.

Therefore, after receiving the information, the transmitting end device obtains specific channel information including frequency offsets through channel estimation.

However, when the mobile communication system operates at high frequencies, a large Doppler effect is encountered. Equation (1) shows the relationship between the frequency offset caused by the Doppler effect and the relevant parameters.

Among them, f _carrier is the frequency of the carrier wave, c is the speed of light, v is the moving speed, and θ is the angle between the moving direction of the terminal and the direction of the incident wave.

It can be seen from formula (1) that in high-frequency channels, such as the 30GHz-300GHz frequency band, because the propagation of electromagnetic waves is more sensitive to the moving speed, it is more susceptible to the influence of the Doppler effect, so the high-frequency Doppler frequency offset will be more serious.

Moreover, in the future, high frequency will be applied to the wireless access network. Due to the different positions of the receiving end, the propagation path has certain uncertainty. The size of the frequency offset generated by the Doppler effect is related to the incident angle of the receiving end, so the frequency offset generated by the Doppler effect has a certain uncertainty.

In this case, according to the existing channel estimation method, the communication system needs to perform frequent detection and estimation of the channel, so as to ensure the acquisition of correct channel information, thus greatly increasing the amount of transmitted information.

Secondly, because high-frequency signals are more particle-like and have shorter wavelengths, they are reflected rather than scattered on most surfaces. Large, but the frequency spread will be relatively small for a single path, as shown in Figure 1. Among them, in Fig. 1, the abscissa represents the frequency domain, and the ordinate represents the power.

Based on this, in various embodiments of the present invention: the receiving end device receives the sounding signal or the reference signal sent by the transmitting end device; in response to the sounding signal or the reference signal, the first information and the reference signal are periodically fed back to the transmitting end device. second information; the first information represents the channel response caused by frequency offset; the second information represents the channel response caused by frequency extension; wherein, the transmission period of the first information is the first period; the second information The information sending period is the second period; the first period is greater than the second period.

Wherein, the application scenario of the embodiment of the present invention may be: the operating frequency of the mobile communication system is a high frequency, and in practical application, the high frequency refers to a frequency greater than or equal to 6 GHz.

Example 1

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

Step 201: Receive a sounding signal or a reference signal sent by the transmitting end device;

Step 202: In response to the sounding signal or the reference signal, periodically feedback the first information and the second information to the transmitting end device.

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

Wherein, the transmission period of the first information is the first period; the transmission period of the second information is the second period; and the first period is greater than the second period.

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

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

H _{f_domain} =H _{f_domain} (f _shift )×H _{f_domain} (f _spread )×H _other (2)

Among them, H _{f_domain} represents the overall impulse response of the channel; H _{f_domain} (f _shift ) represents the channel response determined by the frequency offset in the channel, that is, the first information; H _{f_domain} (f _spread ) represents the multipath channel due to each cluster (cluster) ) The offset part of the frequency brought by the fluctuation of the sub-diameter, that is, the frequency expansion of each cluster, and the impulse response of the corresponding channel, that is, the second information; H _other represents other than the Doppler frequency shift. The channel response caused by the factor; × represents multiplication in the frequency domain.

Equivalently, the three parameters in formula (2) can also be convolved in the time domain to finally obtain the channel response.

In addition, FIG. 3 shows a schematic diagram of frequency offset and frequency expansion at high frequencies. As can be seen from Figure 3, compared with the overall channel change, the channel response caused by the Doppler frequency shift (H _{f_domain} (f _shift )) and the frequency shift frequency spread (H _{f_domain} (f _spread )) is a slow-changing process , and the channel response change caused by frequency extension is faster than the change degree of channel response caused by Doppler frequency offset, so these two information can be fed back slowly (periodically) (the feedback period of frequency extension is smaller than the Doppler frequency shift). frequency offset feedback cycle) to reduce the amount of channel information feedback. However, although H _other changes rapidly, because it accounts for a small proportion of the entire channel information, it may not be fed back according to the actual situation. That is, only the first information and the second information are fed back. Among them, in Fig. 3, the abscissa represents the frequency domain, and the ordinate represents the power.

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

Periodically feeding back third information to the transmitting end device; the third information represents the channel response caused by other factors except frequency offset and frequency extension;

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

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

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

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

The first information, the second information and the third information are extracted from the obtained channel information.

In practical application, the first period, the second period and the third period may be preset as required. The receiving end device may also determine the 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 the channel information to the transmitting end device, the method may further include:

The receiving end device determines the 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 moving speed of the receiving end is low or stationary, or there are few scatterers moving in the surrounding environment, indicating that frequent feedback is not required. frequency offset. Therefore, the receiving end device can reduce the update period of the first information. Conversely, a larger update cycle 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 moving environment, the receiving end device may feed back the first information every time Twice the second message will feed back the first message once.

In practical application, when the operating frequency of the mobile communication system is high frequency (such as above 6GHz), compared with the low frequency operation, the multipath propagation path is less than that of the low frequency, so the phenomenon reflected is: The number of multipath sets after clustering is reduced from 12-20 at low frequencies to 3-4, thereby reducing the total amount of channel information that needs to be acquired. Therefore, channel information can be fed back for each propagation path.

Based on this, in an embodiment, the transmission of data is multi-path propagation;

Correspondingly, for each propagation path, the corresponding channel information is periodically fed back to the transmitting end device.

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

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

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

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

Correspondingly, the receiving end device periodically transmits the channel information through the low frequency uplink.

This embodiment also provides a channel information indication method, as shown in FIG. 4 , the method includes the following steps:

Step 401: the transmitting end device sends a sounding signal or a reference signal to the receiving end device;

Step 402: the receiving end device periodically feeds back the first information and the second information to the transmitting end device in response to the sounding signal or the reference signal;

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

Wherein, the transmission period of the first information is the first period; the transmission period of the second information is the second period; and the first period is greater than the second period.

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

In practical application, the fast-changing channel information in the time domain can be converted into the frequency domain, and then formula (2) is obtained.

H _{f_domain} =H _{f_domain} (f _shift )×H _{f_domain} (f _spread )×H _other (2)

In formula (2), H _{f_domain} represents the overall impulse response of the channel, that is, the channel information in the time domain that needs to be fed back; H _{f_domain} (f _shift ) represents the channel response determined by the frequency offset in the channel, that is, the first information ; H _{f_domain} (f _spread ) represents the offset part of the frequency of the multipath channel due to sub-path fluctuations in each cluster (cluster), that is, the frequency spread of each cluster, and the corresponding impulse response of the channel, that is, the first Two information; H _other represents the channel response caused by other factors except related to the Doppler frequency shift; × represents the frequency domain multiplication.

Equivalently, the three parameters in formula (2) can also be convolved in the time domain to finally obtain the channel response.

In addition, FIG. 3 shows a schematic diagram of frequency offset and frequency expansion at high frequencies. As can be seen from Figure 3, compared with the overall channel change, the channel response caused by the Doppler frequency shift (H _{f_domain} (f _shift )) and the frequency shift frequency spread (H _{f_domain} (f _spread )) is a slow-changing process , and the channel response change caused by frequency extension is faster than the change degree of channel response caused by Doppler frequency offset, so these two information can be fed back slowly (periodically) (the feedback period of frequency extension is smaller than the Doppler frequency shift). frequency offset feedback cycle) to reduce the amount of channel information feedback. However, although H _other changes rapidly, because it accounts for a small proportion of the entire channel information, it may not be fed back according to the actual situation. That is, only the first information and the second information are fed back. Among them, in Fig. 3, the abscissa represents the frequency domain, and the ordinate represents the power.

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

Periodically feeding back third information to the transmitting end device; the third information represents the channel response caused by other factors except frequency offset and frequency extension;

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

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

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

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

The first information, the second information and the third information are extracted from the obtained channel information.

In practical application, the first period, the second period and the third period may be preset as required. The receiving end device may also determine the 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 the channel information to the transmitting end device, the method may further include:

The receiving end device determines the 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 moving speed of the receiving end is low or stationary, or there are few scatterers moving in the surrounding environment, indicating that frequent feedback is not required. frequency offset. Therefore, the receiving end device can reduce the update period of the first information. Conversely, a larger update cycle 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 moving environment, the receiving end device may feed back the first information every time Twice the second message will feed back the first message once.

In practical application, when the operating frequency of the mobile communication system is high frequency (such as above 6GHz), compared with the low frequency operation, the multipath propagation path is less than that of the low frequency, so the phenomenon reflected is: The number of multipath sets after clustering is reduced from 12-20 at low frequencies to 3-4, thereby reducing the total amount of channel information that needs to be acquired. Therefore, channel information can be fed back for each propagation path.

Based on this, in an embodiment, the transmission of data is multi-path propagation;

Correspondingly, for each propagation path, the corresponding channel information is periodically fed back to the transmitting end device.

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

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

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

That is to say, the transmitting end device only sends a probe signal or a reference signal to the receiving end device at high frequency, and further, sends data to the receiving end device only at high frequency;

Correspondingly, the receiving end device periodically transmits the channel information through the low frequency uplink.

Step 403: The transmitting end device 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 the frequency domain, the transmitting end device multiplies the first information and the second information to obtain the channel information, which is expressed by the formula, Then there are:

H _{f_domain} = H _{f_domain} (f _shift )×H _{f_domain} (f _spread ) (3)

Among them, H _{f_domain} represents the overall impulse response of the channel, that is, the channel information in the time domain that needs to be fed back; H _{f_domain} (f _shift ) represents the channel response determined by the frequency offset in the channel, that is, the first information; H _{f_domain} (f _spread ) represents the offset part of the frequency of the multipath channel due to sub-path fluctuations in each cluster, that is, the frequency spread of each cluster, and thus the impulse response of the corresponding channel, that is, the second information; × represents Frequency domain multiplication.

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

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

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

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

In practical applications, high-frequency transmission requires precoding training for data transmission and reception according to the locations of terminals and base stations. Since the transmitting end device and the receiving end device may use separate training methods, it may cause the base station and the terminal to use two completely different sets of transmission codes for uplink and downlink transmission, which leads to poor channel reciprocity and difficult to use. After obtaining the channel information, the transmitting end device uses the obtained channel information to adjust the transmission coding, that is, uses the obtained channel information to participate in the precoding of data, and performs adjustment work before data transmission to improve transmission efficiency.

In the channel information indication method provided by the embodiment of the present invention, a receiving end device receives a sounding signal or a reference signal sent by a transmitting end device; in response to the sounding signal or reference signal, it periodically feeds back the first information and the second information to the transmitting end device. information; the first information represents the channel response caused by frequency offset; the second information represents the channel response caused by frequency extension; wherein, the transmission period of the first information is the first period; The transmission period is the second period; the first period is greater than the second period, the channel response caused by the Doppler frequency offset and the shift frequency expansion is a slow-changing process, and the channel response caused by the frequency expansion changes faster than The degree of change of the channel response caused by the Doppler frequency offset, so the two information can be fed back slowly (periodically) (the feedback period of the frequency extension is smaller than the feedback period of the Doppler frequency offset), so, reducing the The frequency and amount of information fed back by the receiving end device to the channel information.

In addition, data transmission is multi-path propagation; correspondingly, for each propagation path, corresponding channel information is periodically fed back to the sending end device, so that the sending end device is convenient for channel selection.

Embodiment 2

On the basis of the first embodiment, this embodiment describes in detail how to perform an indication process of channel information.

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

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

Step 501: the base station sends a sounding signal/reference signal to a terminal;

Step 502: After receiving the sounding signal/reference signal, the terminal obtains channel information by using the received sounding signal/reference signal; and divides the channel information;

Specifically, the channel information is divided into: channel response H1 (H _{f_domain} (f _shift )) caused by frequency offset, channel response H2 (H _{f_domain} (f _spread )) caused by frequency spread, and channel response H3 caused by other factors (H _other ) three-part information.

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

Step 504: after receiving the three pieces of information, the base station multiplies the three pieces of information to obtain corresponding channel information, and uses the obtained channel information to adjust the transmission coding;

Step 505: the base station sends the sounding signal/reference signal and data to the terminal for the first time;

Step 506: After receiving the sounding signal/reference signal and data, the terminal obtains channel information by utilizing the received sounding signal/reference signal; and divides the channel information;

Specifically, the channel information is divided into: channel response H1 (H _{f_domain} (f _shift )) caused by frequency offset, channel response H2 (H _{f_domain} (f _spread )) caused by frequency spread, and channel response H3 caused by other factors (H _other ) three-part information.

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

Step 508: After receiving the two pieces of information, the base station convolves the two pieces of information and the previously obtained H1 to obtain corresponding channel information, and uses the obtained channel information to adjust the transmission coding;

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

Step 510: After receiving the sounding signal/reference signal and data, the terminal obtains channel information by utilizing the received sounding signal/reference signal; and divides the channel information;

Specifically, the channel information is divided into: channel response H1 (H _{f_domain} (f _shift )) caused by frequency offset, channel response H2 (H _{f_domain} (f _spread )) caused by frequency spread, and channel response H3 caused by other factors (H _other ) three-part information.

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

Among them, it is assumed that the feedback periods corresponding to H1, H2, and H3 are T1, T2, and T3, respectively, so that T1>T2>T3.

Here, since H1 is strongly related to the direction of propagation, its feedback period is the longest; H2 is the fluctuation of the sub-paths in each propagation path, and the fluctuation is large, so the update is relatively fast; H3 is the factor outside the corresponding factors of H1 and H2 The channel response caused by other factors, in other words, H3 is the residual part of the channel response that is not characterized by H1 and H2.

Here, because H3 accounts for a small proportion of the entire channel information, H3 may not be fed back as needed in practical applications.

Embodiment 3

Based on the first embodiment, this embodiment details how to perform the channel information indication process.

The application scenario of this embodiment is: the transmitting end device is a base station, and the receiving end device is a terminal. Only downlink high frequency transmission. In this embodiment, the feedback information is information in the frequency domain.

At this time, the cooperation of high-frequency transmission and low-frequency transmission needs to be performed when channel information feedback is performed. The process of channel information indication in this embodiment, as shown in FIG. 6 , includes the following steps:

Step 601: the base station sends the data signal and the reference signal/probing signal to the terminal through the high frequency;

Step 602: After receiving the signal, the terminal uses the reference signal/probe signal to obtain channel information, and extracts three parts: H1 (H _{f_domain} (f _shift )), H2 (H _{f_domain} (f _spread )), and H3 (H _other );

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

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

Step 604: The base station updates the downlink transmission coding according to the information H1, H2, 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 coding is updated by using the channel information.

Embodiment 4

To implement the method of the embodiment of the present invention, this embodiment provides a receiving end device. As shown in FIG. 7 , the device includes: a receiving unit 71 and a sending unit 72; wherein,

The receiving unit 71 is configured to receive a sounding signal or a reference signal sent by the transmitting end device;

The sending unit 72 is configured to periodically feed back the first information and the second information to the sending end device in response to the sounding signal or the reference signal; the first information represents the channel response caused by the frequency offset; the The second information represents the channel response caused by frequency spreading; wherein,

The transmission period of the first information is the first period; the transmission period of the second information is the second period; the first period is greater than the second period.

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

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

H _{f_domain} =H _{f_domain} (f _shift )×H _{f_domain} (f _spread )×H _other (2)

Among them, H _{f_domain} represents the overall impulse response of the channel, that is, the channel information in the time domain that needs to be fed back; H _{f_domain} (f _shift ) represents the channel response determined by the frequency offset in the channel, that is, the first information; H _{f_domain} (f _spread ) represents the offset part of the frequency of the multipath channel due to sub-path fluctuations in each cluster (cluster), that is, the frequency spread of each cluster, and thus the impulse response of the corresponding channel, that is, the second information; H _other Indicates the channel response caused by factors other than the Doppler shift; × represents the frequency domain phase.

Equivalently, the three parameters in formula (2) can also be convolved in the time domain to finally obtain the channel response.

In addition, FIG. 3 shows a schematic diagram of frequency offset and frequency expansion at high frequencies. As can be seen from Figure 3, compared with the overall channel change, the channel response caused by the Doppler frequency shift (H _{f_domain} (f _shift )) and the frequency shift frequency spread (H _{f_domain} (f _spread )) is a slow-changing process , and the channel response change caused by frequency extension is faster than the change degree of channel response caused by Doppler frequency offset, so these two information can be fed back slowly (periodically) (the feedback period of frequency extension is smaller than the Doppler frequency shift). frequency offset feedback cycle) to reduce the amount of channel information feedback. However, although H _other changes rapidly, because it accounts for a small proportion of the entire channel information, it may not be fed back according to the actual situation. That is to say, the sending unit 72 only feeds back the first information and the second information. Among them, in Fig. 3, the abscissa represents the frequency domain, and the ordinate represents the power.

In one 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 extension;

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

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

Here, in practical application, the device may further include: an acquisition unit and an extraction unit; wherein,

the obtaining unit, configured to obtain channel information by using the sounding signal or the reference signal;

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

In practical application, the first period, the second period and the third period may be preset as required. The receiving end device may also determine the feedback period of each piece of information according to the received sounding signal or reference signal.

Based on this, in an embodiment, the device may further include: a determining unit, configured to use the sounding signal or the reference signal to determine the feedback period of the channel information.

For example, in practical applications, when the first information (frequency offset) does not change much, it indicates that the moving speed of the receiving end is low or stationary, or there are few scatterers moving in the surrounding environment, indicating that frequent feedback is not required. frequency offset. Therefore, the determining unit can reduce the update period of the first information. Conversely, a larger update cycle is required. For example, in a relatively static environment, the determining unit may determine that every time the second information is fed back 10 times, the first information is fed back once; in a dynamic or moving environment, the determining unit may determine that every time the second information is fed back Twice the second message will feed back the first message once.

In practical application, when the operating frequency of the mobile communication system is high frequency (such as 30GHz to 300GHz), compared with operating at low frequency, the multipath propagation path is less than that of low frequency, so the phenomenon reflected is: The number of multipath sets after clustering is reduced from 12-20 at low frequencies to 3-4, thereby reducing the total amount of channel information that needs to be acquired. Therefore, channel information can be fed back for each propagation path.

Based on this, in an embodiment, the transmission of data is multi-path propagation;

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

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

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

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

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

Correspondingly, the sending unit 72 is further configured to: periodically transmit channel information through the low-frequency uplink.

In practical application, the receiving unit 71 and the transmitting unit 72 can be implemented by a transceiver in the receiving end device; the acquiring unit, the extracting unit and the determining unit can be realized by a central processing unit (CPU, Central Processing Unit), a microcomputer in the receiving end device. A processor (MCU, Micro Control Unit), a digital signal processor (DSP, Digital Signal Processor) or a programmable logic array (FPGA, Field-Programmable Gate Array) are implemented.

In order to implement the method of the embodiment of the present invention, this embodiment also provides a channel information indication system. As shown in FIG. 8 , the system includes: a sending end device 81 and a receiving end device 82; wherein,

The transmitting end device 81 is configured to send a sounding signal or a reference signal to the receiving end device 82; and after receiving the first information and the second information, obtain channel information according to the first information and the second information;

The receiving end device 82 is configured to periodically feed back the first information and the second information to the transmitting end device 81 in response to the sounding signal or the reference signal; the first information represents the channel response caused by the frequency offset; The second information represents the channel response caused by frequency spreading;

The transmission period of the first information is the first period; the transmission period of the second information is the second period; the first period is greater than the second period.

At this time, the channel information fed back to the transmitting end device 81 includes: the first information and the second information.

In practical application, the fast-changing channel information in the time domain can be converted into the frequency domain, and then formula (2) is obtained.

H _{f_domain} =H _{f_domain} (f _shift )×H _{f_domain} (f _spread )×H _other (2)

In formula (2), H _{f_domain} represents the overall impulse response of the channel, that is, the channel information in the time domain that needs to be fed back; H _{f_domain} (f _shift )H(f _shift ) represents the channel response determined by the frequency offset in the channel , that is, the first information; H _{f_domain} (f _spread ) represents the offset part of the frequency of the multipath channel due to sub-path fluctuations in each cluster (cluster), that is, the frequency spread of each cluster, thus the corresponding channel Impulse response, that is, the second information; H _other represents the channel response caused by other factors except related to the Doppler frequency shift; × represents multiplication in the frequency domain.

Equivalently, the three parameters in formula (2) can also be convolved in the time domain to finally obtain the channel response.

In addition, FIG. 3 shows a schematic diagram of frequency offset and frequency expansion at high frequencies. As can be seen from Figure 3, compared with the overall channel change, the channel response caused by the Doppler frequency shift (H _{f_domain} (f _shift )) and the frequency shift frequency spread (H _{f_domain} (f _spread )) is a slow-changing process , and the channel response change caused by frequency extension is faster than the change degree of channel response caused by Doppler frequency offset, so these two information can be fed back slowly (periodically) (the feedback period of frequency extension is smaller than the Doppler frequency shift). frequency offset feedback cycle) to reduce the amount of channel information feedback. However, although H _other changes rapidly, because it accounts for a small proportion of the entire channel information, it may not be fed back according to the actual situation. That is, only the first information and the second information are fed back. Among them, in Fig. 3, the abscissa represents the frequency domain, and the ordinate represents the power.

In one embodiment, the receiving end device 82 is further configured to periodically feed back the third information to the transmitting end device 81 when periodically feeding back the first information and the second information to the transmitting end device 81; The third information represents the channel response caused by other factors except frequency offset and frequency extension; the feedback period of the third information is the third period; the second period is greater than the third period;

Correspondingly, the transmitting 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.

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

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

In practical application, the first period, the second period and the third period may be preset as required. The receiving end device may also determine the 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 the channel information to the transmitting end device 81, the receiving end device 82 is further configured to use the sounding signal or the reference signal to determine the feedback period of the channel information.

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

In practical application, when the operating frequency of the mobile communication system is high frequency (such as above 6GHz), compared with the low frequency operation, the multipath propagation path is less than that of the low frequency, so the phenomenon reflected is: The number of multipath sets after clustering is reduced from 12-20 at low frequencies to 3-4, thereby reducing the total amount of channel information that needs to be acquired. Therefore, channel information can be fed back for each propagation path.

Based on this, in an embodiment, the transmission of data is multi-path propagation;

Correspondingly, 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.

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

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

That is to say, the transmitting end device 81 only sends the detection signal or the reference signal to the receiving end device 82 on the high frequency, and further, only sends the data to the receiving end device 82 on the high frequency;

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

When the first information and the second information are information in the frequency domain, the transmitting end device 81 calculates (multiplies) the first information and the second information to obtain the channel information. Expressed in a formula, there are :

H _{f_domain} = H _{f_domain} (f _shift )×H _{f_domain} (f _spread ) (3)

Among them, H _{f_domain} represents the overall impulse response of the channel, that is, the channel information in the time domain that needs to be fed back; H _{f_domain} (f _shift ) represents the channel response determined by the frequency offset in the channel, that is, the first information; H _{f_domain} (f _spread ) represents the offset part of the frequency of the multipath channel due to sub-path fluctuations in each cluster, that is, the frequency spread of each cluster, and thus the impulse response of the corresponding channel, that is, the second information; × represents Frequency domain multiplication.

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

Here, when the receiving-end device 82 sends the first information, the second information and the third information to the transmitting-end device 81, the transmitting-end device 81 according to the first information, the second information and the third information information to obtain the channel information.

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

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

In practical applications, high-frequency transmission requires precoding training for data transmission and reception according to the locations of terminals and base stations. Since the transmitting end device and the receiving end device may use separate training methods, it may cause the base station and the terminal to use two completely different sets of transmission codes for uplink and downlink transmission, which leads to poor channel reciprocity and difficult to use. After obtaining the channel information, the transmitting end device uses the obtained channel information to adjust the transmission coding, that is, uses the obtained channel information to participate in the precoding of data, and performs adjustment work before data transmission to improve transmission efficiency.

In the solution provided by the embodiment of the present invention, the receiving end device receives the sounding signal or the reference signal sent by the transmitting end device; in response to the sounding signal or the reference signal, the first information and the second information are periodically fed back to the transmitting end device; The first information represents the channel response caused by frequency offset; the second information represents the channel response caused by frequency extension; wherein, the transmission period of the first information is the first period; the transmission period of the second information is The second period; the first period is greater than the second period, the channel response caused by Doppler frequency shift and shift frequency extension is a slowly changing process, and the channel response caused by frequency extension changes faster than Doppler The variation of the channel response caused by the frequency offset, so the two information can be fed back slowly (periodically) (the feedback period of the frequency extension is smaller than the feedback period of the Doppler frequency offset), thus reducing the receiving end. The frequency and amount of information that the device feeds back to the channel information.

In addition, data transmission is multi-path propagation; correspondingly, for each propagation path, corresponding channel information is periodically fed back to the sending end device, so that the sending end device is convenient for channel selection.

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 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 having computer-usable program code embodied therein, including but not limited to disk storage, optical storage, and the like.

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 in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (17)

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

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;

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

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

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.

4. The method of claim 1, further comprising:

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

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

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

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

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

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

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 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.

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 in a time domain, and the sending end equipment convolves the first information and the second information to obtain the channel information; or,

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:

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.

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 time domain, and the sending end equipment convolves the first information, the second information and the third information to obtain the channel information; or,

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 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 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.

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;

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

13. The apparatus of claim 12, further comprising: an acquisition unit and an extraction unit; wherein,

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.

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;

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

16. A channel information indication system, the system comprising: a sending terminal device and a receiving terminal device; wherein,

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;

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.

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;

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.

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