WO2018119949A1

WO2018119949A1 - Channel state information phase correction method and apparatus

Info

Publication number: WO2018119949A1
Application number: PCT/CN2016/113258
Authority: WO
Inventors: 王洁
Original assignee: 深圳天珑无线科技有限公司
Priority date: 2016-12-29
Filing date: 2016-12-29
Publication date: 2018-07-05

Abstract

Provided are a channel state information phase correction method and apparatus, relating to the technical field of wireless communications. On the one hand, in the embodiments of the present application, the method comprises: receiving data signals transmitted on various carriers at the same moment; then collecting, according to the data signals, original CSI phase information on the various carriers of various antennas so as to obtain an original CSI phase measurement matrix; and finally, calculating, according to the original CSI phase measurement matrix and a pre-set phase correction algorithm, a corrected CSI phase measurement matrix, thereby improving the accuracy of the corrected CSI phase information, and enabling same to have a greater use value. Therefore, the CSI phase information corrected by the technical solution provided by the embodiments of the present application can be applied to the wireless positioning technology.

Description

Channel state information phase correction method and device

Technical field

The present application relates to the field of wireless communication technologies, and in particular, to a method and an apparatus for correcting channel phase information phases.

Background technique

With the development of wireless communication technologies, CSI (Channel State Information) has broad application prospects in the field of wireless positioning. The CSI describes the attenuation factor of the signal on each transmission path, that is, the value of each element in the channel gain matrix H, such as signal scattering, environmental attenuation, and distance attenuation. Compared with RSS (Received Signal Strength), CSI can not only provide multi-carrier signal strength information, but also provide multi-carrier signal phase information, which enriches the amount of useful information that the physical layer can provide, and can significantly improve wireless. The performance of the positioning system. The wireless positioning technology constructs an offline position state fingerprint database by utilizing the multi-carrier amplitude information provided by the CSI, thereby implementing position estimation and positioning by means of the pattern recognition method in the online phase.

At present, the prior art only utilizes the amplitude information of the multi-carrier provided by the CSI, and does not use the phase information, mainly because the original CSI phase information has a large error, and the reference value for estimating the target position information is not significant. If the phase error caused by the synchronization error of the transmitting and receiving wireless nodes can be eliminated, the phase difference received by each antenna can be directly used to estimate the position information of the positioned target, thereby avoiding the complicated location fingerprint database construction process. Furthermore, even if the position estimation and positioning method of the prior art is still adopted, the location fingerprint database can be enriched by adding CSI phase information, thereby providing more robust signal features, thereby improving positioning accuracy. However, in the prior art, how to eliminate There is no suitable solution for the original CSI phase information error.

Summary of the invention

In view of this, the embodiment of the present application provides a method and a device for correcting the phase of the channel state information, so as to solve the problem that the prior art lacks the proper correction of the original CSI phase information error.

In one aspect, the embodiment of the present application provides a method for correcting a channel state information phase, which is applied to a multi-carrier multi-antenna communication system, where the method includes:

Receiving data signals transmitted on each carrier at the same time;

Collecting original CSI phase information of each antenna on each carrier according to the data signal to obtain an original CSI phase measurement matrix;

The corrected CSI phase measurement matrix is calculated according to the original CSI phase measurement matrix and the preset phase correction algorithm.

The aspect as described above and any possible implementation manner further provide an implementation manner of calculating a modified CSI phase measurement matrix according to the original CSI phase measurement matrix and the preset phase correction algorithm, specifically including:

Calculating the optimal linear phase offset slope and intercept of each element in the matrix by the linear phase shift formula according to the original CSI phase measurement matrix;

Based on the optimal linear phase offset slope and intercept of each element, the corrected CSI phase measurement matrix is obtained by correcting each element by the phase correction formula.

An aspect of the above, and any possible implementation, further providing an implementation manner,

The linear phase shift formula is

among them,

with

Representing the optimal linear phase offset slope and intercept, respectively, φ _m,n is the element of the mth row and n columns in the original CSI phase measurement matrix, that is, the original CSI phase information of the mth antenna on the nth carrier, f For frequency differences between adjacent carriers, a and b represent the slope and intercept of the linear phase offset, respectively.

The phase correction formula is

among them,

To correct the elements of the mth row and n columns in the CSI phase measurement matrix, that is, the corrected CSI phase information of the mth antenna on the nth carrier.

The number of the antennas is at least three, and the antennas are arranged at equal intervals with a spacing of 1/2 of the average wavelength of each carrier;

The number of the carriers is at least 10, and the frequency differences between adjacent carriers are equal.

One of the above technical solutions has the following beneficial effects:

A channel state information phase correction method provided by an embodiment of the present application is applied to a multi-carrier multi-antenna communication system in which both a physical layer of a transmitting end and a physical layer of a receiving end adopt an OFDM modulation mode, by receiving the same time on each carrier. The transmitted data signal collects the original CSI phase information of each antenna on each carrier, and then constructs the original CSI phase measurement matrix according to the original CSI phase information, and corrects the original CSI phase measurement matrix by the preset phase correction algorithm to obtain the corrected CSI phase measurement. matrix. Compared with the prior art, the present application provides a technical solution for correcting original CSI phase information, which can directly utilize the phase difference between the corrected CSI phase information received by each antenna (ie, the corrected original CSI phase information). To estimate the location information of the target, thereby avoiding the complicated process of constructing the location fingerprint database, and enriching the location fingerprint database by increasing the CSI phase information to provide more robust signal characteristics, thereby improving the positioning accuracy.

On the other hand, the embodiment of the present application provides a channel state information phase correction device, which is applied to a multi-carrier multi-antenna communication system, and the device includes:

a receiving module, configured to receive data signals transmitted on each carrier at the same time;

An acquisition module, collecting original CSI phase information of each antenna on each carrier according to the data signal, to obtain an original CSI phase measurement matrix;

The correction module calculates a modified CSI phase measurement matrix according to the original CSI phase measurement matrix and the preset phase correction algorithm.

The above-mentioned aspect and any possible implementation manner further provide an implementation manner, where the calibration module is specifically configured to:

The linear phase shift formula is

among them,

with

The phase correction formula is

among them,

One of the above technical solutions has the following beneficial effects:

A channel state information phase correction apparatus provided in an embodiment of the present application is applied to a multi-carrier multi-antenna communication system in which a physical layer of a transmitting end and a physical layer of a receiving end adopt an OFDM modulation mode. First, the receiving module receives the same time. The data signal transmitted on each carrier, and then the acquisition module collects the original CSI phase information of each antenna on each carrier according to the data signal. Finally, the correction module calculates the correction according to the original CSI phase measurement matrix and the preset phase correction algorithm. CSI phase measurement matrix. Compared with the prior art, the present application provides a technical solution for correcting original CSI phase information, which can directly utilize the phase difference between the corrected CSI phase information received by each antenna (ie, the corrected original CSI phase information). To estimate the location information of the target, thereby avoiding the complicated process of constructing the location fingerprint database, and enriching the location fingerprint database by increasing the CSI phase information to provide more robust signal characteristics, thereby improving the positioning accuracy.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present application. One of ordinary skill in the art can also obtain other drawings based on these drawings without paying for inventive labor.

1 is a schematic flow chart of Embodiment 1 of the present application;

2 is a schematic structural diagram of a multi-carrier multi-antenna communication system according to Embodiment 2 of the present application;

FIG. 3 is a schematic structural view of Embodiment 3 of the present application.

detailed description

For a better understanding of the technical solutions of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

It should be understood that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without departing from the inventive scope are the scope of the present application.

The terms used in the embodiments of the present application are for the purpose of describing particular embodiments only, and are not intended to limit the application. The singular forms "a", "the", and "the"

It should be understood that the term "and/or" as used herein is merely an association describing the associated object, indicating that there may be three relationships, for example, A and/or B, which may indicate that A exists separately, while A and B, there are three cases of B alone. In addition, the character "/" in this article generally indicates that the contextual object is an "or" relationship.

Depending on the context, the word "if" as used herein may be interpreted as "when" or "when" or "in response to determining" or "in response to detecting." Similarly, depending on the context, the phrase "if determined" or "if detected (conditions or events stated)" may be interpreted as "when determined" or "in response to determination" or "when detected (stated condition or event) "Time" or "in response to a test (condition or event stated)".

Embodiment 1

The embodiment of the present application provides a method for correcting the phase of the channel state information, which is applied to a multi-carrier multi-antenna communication system in which the physical layer of the transmitting end and the physical layer of the receiving end adopt the OFDM modulation mode, please refer to FIG. A schematic flowchart of a method provided by applying the embodiment, as shown in the figure, the method includes the following steps:

S101. Receive a data signal transmitted on each carrier at the same time.

Specifically, the physical layer of the transmitter adopts an OFDM modulation method to simultaneously transmit data packets to be transmitted on N carriers; the physical layer of the receiver also adopts an OFDM modulation method, and uses M antennas to simultaneously receive data on N carriers. The packet, wherein the number of antennas is at least three, the antennas are arranged at equal intervals and the spacing is 1/2 of the average wavelength of each carrier, the number of carriers is at least 10, and the frequency differences between adjacent carriers are equal.

S102. Acquire original CSI phase information of each antenna on each carrier according to the data signal to obtain an original CSI phase measurement matrix.

Specifically, the receiver separately collects M*N elements of CSI original phase information of the M antennas on the N carriers according to the received data packet, thereby obtaining a CSI phase measurement matrix Φ, and the matrix can be expressed as

S103. Calculate a modified CSI phase measurement matrix according to the original CSI phase measurement matrix and a preset phase correction algorithm.

Specifically, based on the CSI phase measurement matrix Φ obtained in step S102, the corrected CSI phase measurement matrix is calculated by a preset phase correction algorithm.

Specific steps are as follows:

1) Calculate the optimal linear phase offset slope and intercept of each element in the matrix by the linear phase shift formula according to the original CSI phase measurement matrix.

It should be noted that the linear phase shift formula used in this step is specifically

among them,

with

2) Based on the optimal linear phase offset slope and intercept of each element, the corrected CSI phase measurement matrix is obtained by correcting each element by the phase correction formula.

It should be noted that this step is based on the optimal linear phase shift slope.

And optimal linear phase offset intercept

Phase correction formula

Each element is corrected to obtain each modified CSI phase information, and each modified CSI phase information is used as an element to obtain a modified CSI phase measurement matrix.

The matrix can be expressed as

among them,

To correct the elements of the mth row and n columns in the CSI phase measurement matrix, that is, the corrected CSI phase information of the mth antenna on the nth carrier,

with

Indicates the optimal linear phase offset slope and intercept, respectively, f is the frequency difference between adjacent carriers, φ _m,n is the element of the mth row and n columns in the original CSI phase measurement matrix, that is, the mth antenna is in the first Original CSI phase information on n carriers.

The technical solution of the embodiment of the present application has the following beneficial effects:

It should be noted that the terminals involved in the embodiments of the present application may include, but are not limited to, a personal computer (PC), a personal digital assistant (PDA), a wireless handheld device, a tablet computer, and a tablet computer. Mobile phones, MP3 players, MP4 players, etc.

It should be noted that the execution body of S101 to S103 may be a channel state information phase correction device, and the device may be located in an application of a local terminal, or may be a plug-in or a software development toolkit in an application of a local terminal (Software Development) Functional units such as Kit, SDK, and the like are not specifically limited in the embodiment of the present application.

It is to be understood that the application may be an application (nativeApp) installed on the terminal, or may be a web application (webApp) of the browser on the terminal, which is not limited by the embodiment of the present application.

Embodiment 2

Based on the method for correcting the phase of the channel state information provided in the first embodiment, the technical solution of the present application is described in conjunction with a specific application scenario. 2 is a schematic structural diagram of a multi-carrier multi-antenna communication system according to an embodiment. The system is composed of an OFDM transmitter 1, a transmit antenna 2, an OFDM receiver 3, a receive antenna 4, a receive antenna 5, and a receive antenna 6.

Among them, OFDM transmitter is based on Intel5300 chip design, meets WiFi standard, supports 802.11a/b/g/n protocol, supports 2.4GHz, 5GHz dual-frequency operation, adopts OFDM modulation; transmit antenna adopts 10dB gain omnidirectional dual-frequency antenna, SMA Interface, support 2.4GHz, 5GHz dual-band operation; OFDM receiver based on Intel5300 chip design, meet WiFi standard, support 802.11a/b/g/n protocol, support 2.4GHz, 5GHz dual-band operation, adopt OFDM modulation; three receiving antennas The antenna array is composed of 2.45cm, and each of the three antennas adopts a 10dB gain omnidirectional dual-frequency antenna, and the SMA interface supports 2.4GHz and 5GHz dual-frequency operation.

The method for correcting the phase of the channel state information provided in this embodiment specifically includes the following steps:

1) The OFDM receiver receives the original CSI phase information of the three antennas on the 64 carriers at the same time, and obtains the corresponding CSI phase measurement matrix Φ, which can be expressed as

2) According to the original CSI phase measurement matrix Φ, through the linear phase shift formula

Calculate the optimal linear phase offset slope for each element in the matrix

And intercept

Wherein, the frequency difference f between carriers is 512 KHz;

3) Based on the optimal linear phase offset slope

And optimal linear phase offset intercept

Phase correction formula

The matrix can be expressed as

The test results show that if the original CSI phase measurement matrix Φ is used, the CSI phase information of each antenna measured in each data packet has no correlation, and the phase is randomly distributed in the range of 0 to 2π, which cannot provide effective CSI phase information. If the CSI phase correction method provided by the present application is used, the phase deviation of each antenna of each carrier between different data packets is within 0.05π, which effectively improves the accuracy of the CSI phase information, and makes the CSI phase information change useful.

Embodiment 3

Based on the apparatus for correcting the channel state information phase provided in the first embodiment, the embodiment of the present application further provides an apparatus embodiment for implementing the steps and methods in the foregoing method embodiments.

Please refer to FIG. 3 , which is a functional block diagram of a multi-channel state information phase correction apparatus according to an embodiment of the present application. As shown in FIG. 3, the device is applied to a multi-carrier multi-antenna communication system, and the device includes:

The receiving module 310 is configured to receive data signals transmitted on each carrier at the same time;

The acquiring module 320 is configured to collect original CSI phase information of each antenna on each carrier according to the data signal to obtain an original CSI phase measurement matrix;

The correction module 330 calculates a modified CSI phase measurement matrix according to the original CSI phase measurement matrix and the preset phase correction algorithm.

In a specific implementation process, the calibration module is specifically configured to:

In a specific implementation process,

The linear phase shift formula is

among them,

with

In a specific implementation process,

The phase correction formula is

among them,

In a specific implementation process,

One of the above technical solutions has the following beneficial effects:

A channel state information phase correction apparatus provided in an embodiment of the present application is applied to a multi-carrier multi-antenna communication system in which a physical layer of a transmitting end and a physical layer of a receiving end adopt an OFDM modulation mode. First, the receiving module receives the same time. The data signal transmitted on each carrier, then, The acquisition module collects original CSI phase information of each antenna on each carrier according to the data signal. Finally, the correction module calculates a modified CSI phase measurement matrix according to the original CSI phase measurement matrix and a preset phase correction algorithm. Compared with the prior art, the present application provides a technical solution for correcting original CSI phase information, which can directly utilize the phase difference between the corrected CSI phase information received by each antenna (ie, the corrected original CSI phase information). To estimate the location information of the target, thereby avoiding the complicated process of constructing the location fingerprint database, and enriching the location fingerprint database by increasing the CSI phase information to provide more robust signal characteristics, thereby improving the positioning accuracy.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner. For example, multiple units or components may be combined. Or it can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or hard. The form is implemented in the form of a software functional unit.

The above-described integrated unit implemented in the form of a software functional unit can be stored in a computer readable storage medium. The software functional unit is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to perform the methods of the various embodiments of the present application. Part of the steps. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, which can store program codes. .

The above is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc., which are made within the spirit and principles of the present application, should be included in the present application. Within the scope of protection.

Claims

A method for correcting a channel state information phase is characterized in that, in a communication system applied to a multi-carrier multi-antenna, the method includes:

Receiving data signals transmitted on each carrier at the same time;

Collecting original CSI phase information of each antenna on each carrier according to the data signal to obtain an original CSI phase measurement matrix;

The corrected CSI phase measurement matrix is calculated according to the original CSI phase measurement matrix and the preset phase correction algorithm.
The channel state information phase correction method according to claim 1, wherein the modified CSI phase measurement matrix is calculated according to the original CSI phase measurement matrix and the preset phase correction algorithm, and specifically includes:

Calculating the optimal linear phase offset slope and intercept of each element in the matrix by the linear phase shift formula according to the original CSI phase measurement matrix;

Based on the optimal linear phase offset slope and intercept of each element, the corrected CSI phase measurement matrix is obtained by correcting each element by the phase correction formula.
The channel state information phase correction method according to claim 2, characterized in that

The linear phase shift formula is
among them,
with
Representing the optimal linear phase offset slope and intercept, respectively, φ m,n is the element of the mth row and n columns in the original CSI phase measurement matrix, that is, the original CSI phase information of the mth antenna on the nth carrier, f For frequency differences between adjacent carriers, a and b represent the slope and intercept of the linear phase offset, respectively.
The channel state information phase correction method according to claim 3, characterized in that

The phase correction formula is
among them,
To correct the elements of the mth row and n columns in the CSI phase measurement matrix, that is, the corrected CSI phase information of the mth antenna on the nth carrier.
A method for correcting a phase of a channel state information according to any one of claims 1 to 4, characterized in that

The number of the antennas is at least three, and the antennas are arranged at equal intervals with a spacing of 1/2 of the average wavelength of each carrier;

The number of the carriers is at least 10, and the frequency differences between adjacent carriers are equal.
A channel state information phase correction device, characterized in that, in a communication system applied to a multi-carrier multi-antenna, the device comprises:

a receiving module, configured to receive data signals transmitted on each carrier at the same time;

An acquisition module, collecting original CSI phase information of each antenna on each carrier according to the data signal, to obtain an original CSI phase measurement matrix;

The correction module calculates a modified CSI phase measurement matrix according to the original CSI phase measurement matrix and the preset phase correction algorithm.
The channel state information phase correction device according to claim 6, wherein the correction module is specifically configured to:

Calculating the optimal linear phase offset slope and intercept of each element in the matrix by the linear phase shift formula according to the original CSI phase measurement matrix;

Based on the optimal linear phase offset slope and intercept of each element, the corrected CSI phase measurement matrix is obtained by correcting each element by the phase correction formula.
A channel state information phase correcting apparatus according to claim 7, wherein:

The linear phase shift formula is
among them,
with
Representing the optimal linear phase offset slope and intercept, respectively, φ m,n is the element of the mth row and n columns in the original CSI phase measurement matrix, that is, the original CSI phase information of the mth antenna on the nth carrier, f For frequency differences between adjacent carriers, a and b represent the slope and intercept of the linear phase offset, respectively.
A channel state information phase correcting apparatus according to claim 8, wherein:

The phase correction formula is
among them,
To correct the elements of the mth row and n columns in the CSI phase measurement matrix, that is, the corrected CSI phase information of the mth antenna on the nth carrier.
A channel state information phase correcting apparatus according to any one of claims 1 to 4, characterized in that

The number of the antennas is at least three, and the antennas are arranged at equal intervals with a spacing of 1/2 of the average wavelength of each carrier;

The number of the carriers is at least 10, and the frequency differences between adjacent carriers are equal.