WO2022134621A1

WO2022134621A1 - Carrier phase measurement method and apparatus

Info

Publication number: WO2022134621A1
Application number: PCT/CN2021/112773
Authority: WO
Inventors: 李刚; 任斌; 方荣一; 张振宇; 达人; 孙韶辉
Original assignee: 大唐移动通信设备有限公司
Priority date: 2020-12-25
Filing date: 2021-08-16
Publication date: 2022-06-30
Also published as: CN114697169A; CN114697169B

Abstract

Disclosed in the present application are a carrier phase measurement method and apparatus, which are used to, under relatively severe wireless channel conditions in a complex scenario, solve the problem of deterioration of frequency domain loop phase tracking performance in existing dual-loop orthogonal frequency division multiplexing (OFDM) phase tracking schemes, improve 5G NR carrier phase measurement performance, effectively improve frequency domain loop phase tracking performance, and increase positioning measurement precision. The carrier phase measurement method provided by the present application comprises: performing phase jump detection for an effective subcarrier in a current OFDM symbol of an input baseband signal; determining a frequency domain dynamic feedback output value of the effective subcarrier according to the phase jump detection result; and performing phase correction on the input baseband signal on the basis of the frequency domain dynamic feedback output value.

Description

A kind of carrier phase measurement method and device

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of the Chinese patent application with the application number 202011561065.5 and the application title "A method and device for carrier phase measurement" filed with the China Patent Office on December 25, 2020, the entire contents of which are incorporated herein by reference middle.

technical field

The present application relates to the field of communication technologies, and in particular, to a carrier phase measurement method and device.

Background technique

At present, the 3rd Generation Partnership Project (3GPP) has introduced the following radio access technologies (Radio Access Technology, RAT) based on new radio (New Radio, NR) signals in Release 16 (Rel-16) Positioning method:

NR enhanced cell ID positioning method (E-CID);

NR downlink time difference of arrival location method (DL-TDOA);

NR Uplink Time Difference of Arrival Location Method (UL-TDOA);

NR multi-cell round trip time positioning method (Multi-RTT);

NR downlink angle of departure (DL-AoD);

NR Uplink Angle of Arrival (UL-AoA).

With the Rel-16 positioning method, 90% of users can achieve sub-meter horizontal positioning accuracy.

The carrier phase measurement method can further improve the positioning accuracy and achieve centimeter-level positioning accuracy. The dual-loop phase tracking scheme is an effective method for measuring the carrier phase of Orthogonal Frequency Division Multiplex (OFDM). Through the double-loop structure of the time domain loop and the frequency domain loop, the phase change of the input baseband signal can be tracked and the carrier phase can be obtained. However, under the relatively poor wireless channel conditions, the tracking performance of the frequency domain loop of the dual-loop phase tracking scheme will decrease, and the positioning measurement accuracy is not high.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a carrier phase measurement method and device, which are used to face relatively harsh wireless channel conditions in complex scenarios, and solve the problem of the deterioration of the frequency domain loop phase tracking performance in the existing dual-loop OFDM phase tracking scheme , improve the 5G NR carrier phase measurement performance, effectively improve the phase tracking performance of the frequency domain loop, and improve the positioning measurement accuracy.

A carrier phase measurement method provided by an embodiment of the present application includes:

Phase hopping detection is performed for the valid subcarriers in the current OFDM symbol of the input baseband signal;

Determine the frequency domain dynamic feedback output value of the effective subcarrier according to the phase hopping detection result;

Based on the frequency domain dynamic feedback output value, phase correction is performed on the input baseband signal.

Through this method, phase hopping detection is performed for the valid subcarriers in the current OFDM symbol of the input baseband signal; the frequency domain dynamic feedback output of the valid subcarriers is determined according to the phase hopping detection result. value; based on the dynamic feedback output value in the frequency domain, phase correction is performed on the input baseband signal, which can be phase correction in the frequency domain and/or time domain, thereby realizing real-time correction at the subcarrier level and effectively reducing the phase of the input baseband signal. The influence of hopping or continuous hopping improves the phase tracking performance of the frequency domain loop, thereby also improving the final tracking accuracy of the time domain loop output. measurement accuracy. That is, the embodiment of the present application is oriented to the relatively poor wireless channel conditions in complex scenarios, solves the problem of the deterioration of the frequency domain loop phase tracking performance in the existing dual-loop OFDM phase tracking scheme, improves the 5G NR carrier phase measurement performance, and effectively Improved phase tracking performance for frequency domain loops.

Optionally, the effective subcarriers include subcarriers corresponding to the frequency domain of the positioning reference signal in the OFDM symbol.

Optionally, the phase correction includes:

For the current OFDM symbol of the input baseband signal, use the time-domain phase correction value to perform time-domain phase correction, and then perform time-frequency domain transformation;

Extract the subcarrier corresponding to the positioning reference signal of the frequency domain position of the current OFDM symbol as an effective subcarrier, and use the frequency domain phase correction value to perform frequency domain phase correction on the positioning reference signal of the current effective subcarrier;

Wherein, the frequency domain phase correction value and/or the time domain phase correction value are determined based on the frequency domain dynamic feedback output value.

Optionally, the phase jump detection specifically includes:

Compare the phase of the positioning reference signal of the current valid subcarrier after the frequency domain phase correction with the phase of the positioning reference signal of the valid subcarrier sent by the transmitting end, and use the frequency domain phase difference between the two as the corresponding current valid subcarrier. Frequency domain phase difference;

Based on the phase difference in the frequency domain, it is determined that the currently valid subcarrier belongs to one of the following three cases:

Case 1. Abnormal phase jump of a single subcarrier;

Case 2: Multiple subcarriers have abnormal continuous phase hopping;

Case 3: There is no abnormal jump in the subcarrier phase.

Optionally, if the absolute value of the frequency domain phase difference corresponding to the currently valid subcarrier is greater than the first threshold value, it is determined to belong to the first case;

If both of the following conditions are met, it is determined to belong to the second case:

The first condition: the absolute value of the frequency domain phase difference corresponding to the currently valid subcarrier is greater than the second threshold value;

The second condition: the absolute value of the accumulated frequency-domain phase difference is greater than the third threshold value; wherein, the accumulated frequency-domain phase difference is obtained in the following manner: the frequency-domain phase difference corresponding to the current effective subcarrier is the same as the previous When the sign bit of the frequency domain phase difference corresponding to an adjacent valid subcarrier is the same, the frequency domain phase difference is accumulated; the sign bit of the frequency domain phase difference corresponding to the current valid subcarrier and the frequency domain phase difference corresponding to the previous adjacent valid subcarrier When not, clear the accumulated frequency domain phase difference result;

If none of the above-mentioned conditions of Situation 1 and Situation 2 are met, it is determined to belong to Situation 3;

If the above conditions of Situation 1 and Situation 2 are met, it is finally determined to belong to Situation 2.

Optionally, the determining the frequency domain dynamic feedback output value of the effective subcarrier according to the phase hopping detection result specifically includes:

Calculate the dynamic adjustment feedback coefficient of the current effective subcarrier;

The frequency domain dynamic feedback output value of the effective subcarrier is obtained by multiplying the frequency domain phase difference corresponding to the effective subcarrier by the dynamic adjustment feedback coefficient of the current effective subcarrier.

Optionally,

For the third case: the dynamically adjusted feedback coefficient is the first feedback coefficient, and the first feedback coefficient is determined according to the time delay detected by the frequency domain loop of the previous OFDM symbol;

For the first case: the dynamic adjustment feedback coefficient is the first feedback coefficient multiplied by the preset first reduction coefficient;

For the second case: the dynamic adjustment feedback coefficient is the first feedback coefficient multiplied by the preset first reduction coefficient, and then multiplied by the preset second reduction coefficient.

Optionally, the frequency domain phase correction value is determined by the following steps:

In the current OFDM symbol, the frequency domain dynamic feedback output values of the effective subcarriers before the current effective subcarrier are accumulated in the order of effective subcarriers, and the accumulation result is used as the frequency domain phase correction value of the current effective subcarrier.

Optionally, the method further includes:

Multiplying the frequency domain phase correction value of the preset effective subcarriers of the current OFDM symbol by the preset time domain feedback coefficient to obtain the time domain feedback value of the current OFDM symbol.

Optionally, the time-domain phase correction value is determined by the following steps:

The time domain feedback values of the OFDM symbols before the current OFDM symbol are accumulated in the order of OFDM symbols, and the accumulated result is used as the time domain phase correction value of the current OFDM symbol.

A carrier phase measurement device provided by an embodiment of the present application includes:

memory for storing program instructions;

The processor is used for calling the program instructions stored in the memory, and executes according to the obtained program:

Optionally, the phase correction includes:

Extracting the subcarriers corresponding to the positioning reference signal of the frequency domain position of the current OFDM symbol as valid subcarriers, and using the frequency domain phase correction value to perform frequency domain phase correction on the positioning reference signal of the current valid subcarriers;

Optionally, the phase jump detection specifically includes:

Case 1. Abnormal phase jump of a single subcarrier;

Case 2: Multiple subcarriers have abnormal continuous phase hopping;

Case 3: There is no abnormal jump in the subcarrier phase.

Optionally, the frequency domain dynamic feedback output value of the effective subcarrier is determined according to the phase hopping detection result, specifically including:

Optionally,

Optionally, the processor determines the frequency domain phase correction value through the following steps:

Optionally, the processor is also used for:

Optionally, the processor determines the time-domain phase correction value through the following steps:

Another carrier phase measurement device provided by the embodiment of the present application includes:

a first unit, configured to perform phase hopping detection for valid subcarriers in the current OFDM symbol of the input baseband signal;

a second unit, configured to determine the frequency domain dynamic feedback output value of the effective subcarrier according to the phase hopping detection result;

The third unit is configured to perform phase correction on the input baseband signal based on the frequency domain dynamic feedback output value.

Another embodiment of the present application provides a computing device, which includes a memory and a processor, wherein the memory is used for storing program instructions, and the processor is used for calling the program instructions stored in the memory, according to the obtained program Perform any of the above methods.

Another embodiment of the present application provides a computer storage medium, where the computer storage medium stores computer-executable instructions, where the computer-executable instructions are used to cause the computer to execute any one of the foregoing methods.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic flowchart of an overall solution provided by an embodiment of the present application;

2 is a schematic diagram of a frequency domain loop phase tracking value in the prior art;

3 is a schematic diagram of a frequency domain loop phase tracking value provided by an embodiment of the present application;

FIG. 4 is a schematic flowchart of a carrier phase measurement method provided by an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a carrier phase measurement apparatus provided by an embodiment of the present application;

FIG. 6 is a schematic structural diagram of another carrier phase measurement apparatus provided by an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

Compared with the existing positioning methods in 3GPP Rel-16, the carrier phase measurement method can further improve the positioning accuracy and achieve centimeter-level positioning accuracy. The dual-loop phase tracking scheme is an effective method for measuring the carrier phase of the Orthogonal Frequency Division Multiplex (OFDM). Through the double-loop structure of the time domain loop and the frequency domain loop, the phase change of the input baseband signal can be tracked and the carrier phase can be obtained. When the carrier frequency of the 5G system is 3.5Hz, the carrier wavelength is about 8.6cm. If the carrier phase measurement accuracy is 10%, the positioning measurement error is less than 8.6*10%=0.86cm.

When the wireless channel conditions are good, the dual-loop phase tracking scheme can effectively track the carrier phase of 5G NR and achieve high-precision positioning. However, under relatively poor wireless channel conditions, such as multipath wireless propagation conditions with low signal-to-noise ratio and/or low Rice factor, the phase of the input signal itself will hop or hop continuously. At this time, the tracking performance of the frequency domain loop of the dual-loop phase tracking scheme will be degraded. The main reason is that the phase jump of the input signal causes an incorrect correction signal to be generated in the frequency domain loop correction process, resulting in a large tracking error in the frequency domain loop, which may cause a series of problems such as tracking failure and cycle slip.

Therefore, in the 5G NR system, the realization of high-precision carrier phase positioning requires accurate acquisition of the carrier phase value of the received OFDM symbol. The embodiment of the present application proposes a solution for improving 5G NR carrier phase measurement performance, which can provide higher carrier phase measurement performance and is suitable for high-precision positioning in complex scenarios.

The methods and devices provided in the embodiments of the present application are conceived based on the same application. Since the methods and devices have similar principles for solving problems, the implementations of the devices and methods can be referred to each other, and repeated descriptions will not be repeated here.

The technical solutions provided in the embodiments of the present application can be applied to various systems, especially 5G systems. For example, applicable systems may be global system of mobile communication (GSM) system, code division multiple access (CDMA) system, wideband code division multiple access (Wideband Code Division Multiple Access, WCDMA) general packet Wireless service (general packet radio service, GPRS) system, long term evolution (long term evolution, LTE) system, LTE frequency division duplex (frequency division duplex, FDD) system, LTE time division duplex (time division duplex, TDD), general Mobile system (universal mobile telecommunication system, UMTS), worldwide interoperability for microwave access (WiMAX) system, 5G system and 5G NR system, etc. These various systems include terminal equipment and network equipment.

The terminal device involved in the embodiments of the present application may be a device that provides voice and/or data connectivity to a user, a handheld device with a wireless connection function, or other processing device connected to a wireless modem. In different systems, the name of the terminal equipment may be different. For example, in the 5G system, the terminal equipment may be called user equipment (UE). Wireless end devices may communicate with one or more core networks via the RAN, and the wireless end devices may be mobile end devices such as mobile phones (or "cellular" phones) and computers with mobile end devices, for example, which may be portable , pocket, handheld, computer built-in or vehicle mounted mobile devices that exchange language and/or data with the radio access network. For example, personal communication service (PCS) phones, cordless phones, session initiated protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (personal digital assistants), PDA) and other devices. Wireless terminal equipment may also be referred to as system, subscriber unit, subscriber station, mobile station, mobile station, remote station, access point , a remote terminal device (remote terminal), an access terminal device (access terminal), a user terminal device (user terminal), a user agent (user agent), and a user device (user device), which are not limited in the embodiments of the present application.

The network device involved in the embodiments of the present application may be a base station, and the base station may include multiple cells. Depending on the specific application, the base station may also be called an access point, or may refer to a device in the access network that communicates with wireless terminal devices through one or more sectors on the air interface, or other names. The network device can be used to convert received air frames to and from internet protocol (IP) packets and act as a router between the wireless end device and the rest of the access network, which can include the Internet. Protocol (IP) communication network. The network devices may also coordinate attribute management for the air interface. For example, the network device involved in the embodiments of the present application may be a network device (base transceiver station, BTS) in a global system for mobile communications (GSM) or a code division multiple access (code division multiple access, CDMA). ), it can also be a network device (NodeB) in wide-band code division multiple access (WCDMA), or it can be an evolved network device in a long term evolution (LTE) system (evolutional node B, eNB or e-NodeB), 5G base station in 5G network architecture (next generation system), but also home evolved node B (HeNB), relay node (relay node), home base station ( femto), pico base station (pico), etc., which are not limited in the embodiments of the present application.

The various embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the display order of the embodiments of the present application only represents the sequence of the embodiments, and does not represent the advantages and disadvantages of the technical solutions provided by the embodiments.

The technical solutions provided by the embodiments of the present application are implemented on the receiver side, and the implementation entities are:

For uplink positioning, it is implemented by the base station.

For downlink positioning, it is implemented by the UE.

For positioning purposes, a positioning reference signal is included in the wireless signal transmitted by a 5G NR transmitter. After receiving the wireless signal, according to the configuration information, the receiver extracts a time-domain Orthogonal Frequency Division Multiplex (OFDM) symbol including a positioning reference signal in the baseband. The input baseband signal of the technical solution provided by the embodiment of the present application is the time-domain sample point data of the OFDM symbol from which the cyclic prefix has been removed.

The main solution provided by the embodiment of the present application is shown in FIG. 1 , and the processing flow included is as follows:

(1) Time domain correction: Based on the time domain phase correction value (ie, the phase update value) provided by the time domain phase correction value update module, this step performs time domain phase correction on the current OFDM symbol of the input baseband signal.

Among them, as shown in FIG. 1 , the solution of the embodiment of the present application adopts two feedback loops, a time domain loop and a frequency domain loop. The feedback value of the time domain loop (the time domain phase correction value) is updated once per OFDM symbol, and is provided by the time domain phase correction value updating module.

(2) Time-frequency domain transformation: transform the baseband signal after time domain phase correction from time domain to frequency domain.

(3) Frequency domain correction: Extract the subcarriers corresponding to the frequency domain of the positioning reference signal, which may be all or part of them, which are called effective subcarriers.

Specifically, the location reference signal has been placed in the frequency domain position of the OFDM symbol of the input baseband signal. In this step, the subcarriers corresponding to these positioning reference signals need to be extracted from the frequency domain position as effective subcarriers.

For the positioning reference signal of the effective subcarrier, the following two sequences can be used for frequency domain correction:

Do frequency domain phase correction in order from the lowest frequency point to the highest frequency point;

The frequency domain phase correction is performed in order from the highest frequency point to the lowest frequency point.

The frequency-domain phase correction value (ie, the frequency-domain compensation value) used in the frequency-domain phase correction is provided by the frequency-domain phase correction value updating module. As shown in FIG. 1 , the solution of the embodiment of the present application adopts two feedback loops, a time domain loop and a frequency domain loop. The feedback value of the frequency domain loop (that is, the frequency domain phase correction value) is updated in real time for each effective subcarrier, and is provided by the frequency domain phase correction value updating module.

(4) Frequency domain phase difference calculation: compare the phase of the positioning reference signal after frequency domain phase correction with the phase of the received positioning reference signal corresponding to the valid sub-carrier (that is, the positioning reference signal sent by the transmitting end), and obtain two the frequency domain phase difference.

(5) Phase hopping detection: The following judgment is made on the frequency domain phase difference of the effective subcarriers in an OFDM symbol (among the multiple external input OFDMs, including the OFDM symbol of the positioning reference signal) obtained in step (4), and output Phase jump detection results, there are the following three phase jump situations:

1. Abnormal phase hopping of a single subcarrier.

Judgment basis: the absolute value of the phase difference in the frequency domain corresponding to the currently valid subcarrier is greater than the first threshold value.

2. The continuous phase of multiple sub-carriers jumps abnormally.

Judgment Basis: The following two conditions need to be met at the same time:

The first condition is judged based on: the absolute value of the frequency domain phase difference of the current subcarrier is greater than the second threshold value.

The second condition judgment basis: when the sign bit of the frequency domain phase difference between the current subcarrier and the previous adjacent effective subcarrier is the same, the phase difference is accumulated. When the sign bit of the frequency domain phase difference between the current subcarrier and the previous adjacent effective subcarrier is different, the accumulated phase difference result is cleared. This condition is met if the absolute value of the accumulated phase difference is greater than the third threshold value.

3. There is no abnormal jump in the subcarrier phase.

Judgment basis: When the above two transition conditions are not met at the same time.

If the phase hopping of a certain subcarrier complies with the above-mentioned case 1 and case 2 at the same time, the output only belongs to the result of case 2.

Among them, the determination methods of the above three threshold values are for example:

The method for determining the first threshold value and the second threshold value (the relationship between the two threshold values is not limited):

For the first OFDM symbol: a fixed value is preset based on different scenarios. This value can be set according to simulation or determined based on field tests.

For the remaining OFDM symbols: based on the average value of the absolute value of the effective sub-carrier frequency domain phase difference of the previous OFDM symbol, multiplied by an amplification factor (preset constant).

The third threshold value determination method: π multiplied by a reduction coefficient (preset constant).

(6) Frequency domain dynamic feedback:

First, according to the three phase hopping conditions in step (5), calculate the dynamic adjustment feedback coefficient of each effective subcarrier (that is, the following frequency domain feedback coefficient):

Case 1. There is no abnormal jump in the subcarrier phase:

The frequency domain feedback coefficient is the first feedback coefficient, and the value is determined according to the time delay detected by the frequency domain loop of the previous symbol. The larger the time delay, the larger the value of the frequency domain feedback coefficient. Specifically, for example, the time delay is divided into several intervals, and different frequency domain feedback coefficients are used in different intervals.

Case 2. Abnormal phase hopping of a single subcarrier:

The frequency domain feedback coefficient is the first feedback coefficient multiplied by the first reduction coefficient (a preset constant, which may be different from the aforementioned reduction coefficient).

Case 3: The frequency domain feedback coefficient of the continuous phase hopping of multiple subcarriers is the first feedback coefficient multiplied by the first reduction coefficient, and then multiplied by the second reduction coefficient (the preset constant, which may be different from the aforementioned reduction coefficient).

Secondly, multiply the frequency domain phase difference of step (4) by the dynamic adjustment feedback coefficient to obtain the frequency domain dynamic feedback output value.

(7) Frequency domain phase correction value update: In the current OFDM symbol, the frequency domain dynamic feedback output values are accumulated in the order of valid subcarriers, and the accumulation result before the current subcarrier is used as the frequency domain phase correction value of the current subcarrier.

(8) Time domain feedback: The frequency domain phase correction value of the designated subcarrier (preset subcarrier, not fixed to a certain subcarrier) of the current OFDM symbol is multiplied by the time domain feedback coefficient (preset constant) to obtain the symbol time domain feedback value. All OFDM symbols use the same designated subcarriers.

(9) Time domain phase correction value update: the time domain feedback values are accumulated in the order of OFDM symbols, and the accumulation result before the current OFDM symbol is used as the time domain phase correction value of the current symbol.

An illustration of a specific embodiment is given below.

For example, a specific solution flow provided in the embodiment of the present application includes the following steps:

(1) Time domain correction:

The input baseband signal is the input OFDM symbol from which the cyclic prefix has been removed, and the nth sampling point of the mth OFDM symbol is defined as

The time domain of the input baseband is first time-domain corrected:

For m=0:

For m>0:

In the formula,

is the mth OFDM symbol after time domain correction, the time domain correction phase

Provided by the time domain phase update module (j is an imaginary number symbol), that is, the time domain corrected phase value updated in step 9.

(2) Time-frequency domain transformation:

The time-domain corrected OFDM symbols are processed by FFT

Transform from time domain to frequency domain signal

Wherein, l represents the lth subcarrier in the mth OFDM symbol.

(3) Frequency domain correction:

from

All sub-carriers corresponding to the frequency domain of the positioning reference signal are extracted from

It is called an effective subcarrier, where k represents the number of the extracted subcarrier, that is, the number of the effective subcarrier. For valid subcarriers, frequency domain correction is performed in order from the zeroth subcarrier to the last subcarrier:

For k=0:

For k>0:

in,

and

Provided by the frequency domain phase update module.

(4) Frequency domain phase difference calculation:

After the frequency domain signal is corrected, the frequency domain phase difference calculation is performed. The transmitter positioning reference signal is

Positioning reference signal after frequency domain correction at the receiver

Get the frequency domain phase difference of the two

(5) Phase jump detection:

By judging the phase differences of the effective sub-carriers in an OFDM symbol in turn, three kinds of phase hopping situations are output:

Abnormal phase jump of a single subcarrier:

Judgments based:

Continuous phase hopping of multiple subcarriers:

Judgment Basis: The following two conditions need to be met at the same time:

The first condition is judged based on:

The second condition judgment basis: when the sub-carrier phase difference is the same as the sign of the previous adjacent sub-carrier phase difference, the difference is accumulated to obtain

When the subcarrier phase difference is not the same as the sign of the previous adjacent subcarrier phase difference,

if it appears

, this condition is satisfied.

Subcarrier phase without hopping:

Judgment basis: When the above two transition conditions are not met.

Among them, the method of determining the threshold value:

threshold_1 determination method: previous symbol

The average value of is multiplied by the magnification factor a, a>1.

threshold_2 determination method: previous symbol

The average value of is multiplied by the magnification factor b, b>1.

Threshold_3 determination method: π multiplied by a reduction coefficient c, 0<c<1.

(6) Frequency domain dynamic feedback:

First, according to the three phase hopping conditions in step (5), the dynamic adjustment feedback coefficient a _f (k) of each effective sub-carrier is obtained.

Subcarrier phase without hopping:

a _f (k)=a _f

Among them, 0<a _f ≤1. a _f is determined according to the time delay τ detected by the frequency domain loop of the previous OFDM symbol. The greater the delay, the greater the value of a _f . E.g:

When 0us<τ<50us: a _f =0.4

When 50<τ<500us: a _f =0.6

When 500us<τ: a _f =0.8

Abnormal phase jump of a single subcarrier:

a _f (k)=α*a _f , where α is the first reduction factor, 0≤α≤1.

When multiple subcarriers continuously phase abnormally hop:

a _f (k)=α*β*a _f (k-1), where β is the second reduction factor, 0≤β≤1.

Second, multiply the frequency domain phase difference in step (4) by the dynamic adjustment feedback coefficient to obtain the frequency domain dynamic feedback output value:

(7) Frequency domain phase correction value update:

For k=0:

For k>0:

(8) Time domain feedback:

Take the frequency domain phase correction value of the first subcarrier of the current symbol

Multiply by the time domain feedback coefficient a _t to obtain the time domain feedback value fb_time ^m of the symbol:

This step belongs to the aforementioned time domain loop correction.

(9) Time domain phase correction value update:

For m=0:

For m>0:

To sum up, the technical solutions provided in the embodiments of the present application can achieve the following beneficial effects:

Real-time correction at subcarrier level is realized, effectively reducing the influence of input phase hopping or continuous hopping, and improving the phase tracking performance of the frequency domain loop, specifically:

Avoid peaks in the phase tracking value of the frequency domain loop (corresponding to the processing of the above-mentioned "abnormal phase jump of a single subcarrier");

Avoid large jumps and cycle jumps in the phase tracking value of the frequency domain loop (corresponding to the above-mentioned processing of "multiple subcarrier continuous phase abnormal jumps");

The tracking accuracy of the frequency domain loop is improved, thereby also improving the final tracking accuracy of the time domain loop output. Corresponding to the overall effect of the above-mentioned phase jump detection and frequency domain dynamic feedback processing, the phase peaks, large jumps and cycle slips in the frequency domain loop are eliminated, that is, the phase tracking accuracy of the frequency domain loop is improved.

Examples of simulation results:

In downlink positioning, a moving UE tracks an example in which a base station sends a positioning reference signal. Among them, the signal-to-noise ratio SNR=5dB, and the Rice factor K=5dB of the fading channel.

Because the input signal-to-noise ratio is relatively low, the Rice factor is relatively small. The signal received by the receiver has serious phase hopping, which can easily lead to problems in the phase tracking of the frequency domain loop.

FIG. 2 shows the phase tracking result of the frequency domain loop before the embodiment of the present application is adopted. It can be seen that the tracking phase burr is relatively large, and there is a serious phase cycle slip (cycle slip means that the phase jump value is 2pi).

FIG. 3 shows the phase tracking result of the frequency domain loop after using the embodiment of the present application. It can be seen that: after using the method of the embodiment of the present application, the tracking phase burr is small, and the phase cycle slip is successfully suppressed.

To sum up, referring to FIG. 4 , a carrier phase measurement method provided by an embodiment of the present application includes:

S101. Perform phase hopping detection for valid subcarriers in the current OFDM symbol of the input baseband signal;

S102, according to the phase hopping detection result, determine the frequency domain dynamic feedback output value of the effective subcarrier;

S103. Perform phase correction on the input baseband signal based on the frequency domain dynamic feedback output value.

Wherein, based on the dynamic feedback output value in the frequency domain, phase correction is performed on the input baseband signal, which may be phase correction in the frequency domain and/or time domain, thereby realizing real-time correction at the subcarrier level and effectively reducing the phase of the input baseband signal. The influence of hopping or continuous hopping improves the phase tracking performance of the frequency domain loop, thereby also improving the final tracking accuracy of the time domain loop output. The tracking phase glitch is small, and the phase cycle slip is successfully suppressed, which improves positioning measurement accuracy.

For example, a carrier phase measurement method includes:

Phase hopping detection is performed for the valid subcarriers in the current OFDM symbol of the input baseband signal; for example, the detection result is an abnormal phase hopping of a single subcarrier;

For the abnormal phase hopping of a single subcarrier, the dynamic adjustment feedback coefficient of the effective subcarrier is calculated as the first feedback coefficient multiplied by the first reduction coefficient; then the dynamic adjustment feedback coefficient of the effective subcarrier is multiplied by the corresponding effective subcarrier. The frequency domain phase difference is obtained to obtain the frequency domain dynamic feedback output value corresponding to the effective subcarrier;

In the current OFDM symbol, the frequency domain dynamic feedback output values are accumulated in the order of the effective subcarriers, and the accumulation result before the current effective subcarrier is used as the frequency domain phase correction value of the current effective subcarrier;

For the baseband signal transformed to the frequency domain, extract the subcarriers corresponding to the frequency domain of the positioning reference signal as valid subcarriers; for the positioning reference signals of valid subcarriers, use the valid subcarriers in order from the lowest frequency point to the highest frequency point The frequency-domain phase correction values corresponding to the sub-carriers are sequentially subjected to frequency-domain phase correction.

That is, in the embodiment of the present application, only the frequency domain phase correction may be performed. Of course, in the same way, only the time domain phase correction may be performed, which will not be repeated here.

Optionally, the phase correction includes:

It should be noted that, in this embodiment of the present application, only the frequency domain phase correction may be performed, or only the time domain phase correction may be performed. Of course, the best effect is to perform both the frequency domain phase correction and the time domain phase correction.

Optionally, the phase jump detection specifically includes:

Compare the phase of the positioning reference signal of the current valid subcarrier after the frequency domain phase correction with the phase of the positioning reference signal of the valid subcarrier sent by the transmitting end, and use the frequency domain phase difference between the two as the phase corresponding to the current valid subcarrier. Frequency domain phase difference;

Case 1. Abnormal phase jump of a single subcarrier;

Case 2: Multiple subcarriers have abnormal continuous phase hopping;

Case 3: There is no abnormal jump in the subcarrier phase.

The second condition: the absolute value of the accumulated frequency domain phase difference is greater than the third threshold value; wherein, the accumulated frequency domain phase difference is obtained in the following way: the frequency domain phase difference corresponding to the current effective subcarrier is the same as the previous one. When the sign bit of the frequency domain phase difference corresponding to an adjacent effective subcarrier is the same, the frequency domain phase difference is accumulated; the sign bit of the frequency domain phase difference corresponding to the current effective subcarrier and the frequency domain phase difference corresponding to the previous adjacent effective subcarrier When not, clear the accumulated frequency domain phase difference result;

Optionally,

Optionally, the method further includes:

Referring to FIG. 5, a carrier phase measurement device provided by an embodiment of the present application includes:

a memory 520 for storing program instructions;

The processor 500 is configured to call the program instructions stored in the memory, and execute according to the obtained program:

Optionally, the phase correction includes:

Optionally, the phase jump detection specifically includes:

Based on the frequency domain phase difference, it is determined that the currently valid subcarrier belongs to one of the following three cases:

Case 1. Abnormal phase hopping of a single subcarrier;

Case 2: Multiple subcarriers have abnormal continuous phase hopping;

Case 3: There is no abnormal jump in the subcarrier phase.

Optionally,

Optionally, the processor 500 determines the frequency domain phase correction value through the following steps:

Optionally, the processor 500 is further configured to:

Optionally, the processor 500 determines the time domain phase correction value through the following steps:

The transceiver 510 is used for receiving and transmitting data under the control of the processor 500 .

5, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 500 and various circuits of memory represented by memory 520 are linked together. The bus architecture may also link together various other circuits, such as peripherals, voltage regulators, and power management circuits, which are well known in the art and, therefore, will not be described further herein. The bus interface provides the interface. Transceiver 510 may be multiple elements, ie, including a transmitter and a receiver, providing a means for communicating with various other devices over a transmission medium. The processor 500 is responsible for managing the bus architecture and general processing, and the memory 520 may store data used by the processor 500 in performing operations.

The processor 500 can be a central processor (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (Field-Programmable Gate Array, FPGA) or a complex programmable logic device (Complex Programmable Logic Device). , CPLD).

Referring to FIG. 6 , another carrier phase measurement apparatus provided by an embodiment of the present application includes:

The first unit 11 is configured to perform phase hopping detection for valid subcarriers in the current OFDM symbol of the input baseband signal;

The second unit 12 is configured to determine the frequency domain dynamic feedback output value of the effective subcarrier according to the phase hopping detection result;

The third unit 13 is configured to perform phase correction on the input baseband signal based on the frequency domain dynamic feedback output value.

The apparatus provided by the embodiment of the present application may be a base station, or may be a device such as a terminal.

It should be noted that the division of units in the embodiments of the present application is illustrative, and is only a logical function division, and other division methods may be used in actual implementation. 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 alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The integrated unit, if implemented in the form of a software functional unit and sold or used as an independent product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application can be embodied in the form of software products in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, and the computer software products are stored in a storage medium , including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program codes .

An embodiment of the present application provides a computing device, and the computing device may specifically be a desktop computer, a portable computer, a smart phone, a tablet computer, a personal digital assistant (Personal Digital Assistant, PDA), and the like. The computing device may include a central processing unit (Center Processing Unit, CPU), a memory, an input/output device, etc., the input device may include a keyboard, a mouse, a touch screen, etc., and the output device may include a display device, such as a liquid crystal display (Liquid Crystal Display, LCD), Cathode Ray Tube (CRT), etc.

The memory may include read only memory (ROM) and random access memory (RAM) and provide the processor with program instructions and data stored in the memory. In the embodiments of the present application, the memory may be used to store the program of any of the methods provided in the embodiments of the present application.

The processor invokes the program instructions stored in the memory, and the processor is configured to execute any one of the methods provided in the embodiments of the present application according to the obtained program instructions.

An embodiment of the present application provides a computer storage medium for storing computer program instructions used for the apparatus provided by the above embodiment of the present application, which includes a program for executing any of the methods provided by the above embodiment of the present application.

The computer storage medium can be any available medium or data storage device that can be accessed by a computer, including but not limited to magnetic storage (eg, floppy disk, hard disk, magnetic tape, magneto-optical disk (MO), etc.), optical storage (eg CD, DVD, BD, HVD, etc.), and semiconductor memory (eg, ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid-state disk (SSD)), etc.

The methods provided in the embodiments of the present application may be applied to terminal devices, and may also be applied to network devices.

The terminal equipment may also be referred to as user equipment (User Equipment, referred to as "UE"), mobile station (Mobile Station, referred to as "MS"), mobile terminal (Mobile Terminal), etc. Optionally, the terminal can be Have the ability to communicate with one or more core networks via a Radio Access Network (RAN), for example, the terminal may be a mobile phone (or a "cellular" phone), or a computer with a mobile nature, etc., For example, the terminal may also be a portable, pocket-sized, hand-held, computer-built, or vehicle-mounted mobile device.

A network device, which may be a base station (eg, an access point), refers to a device in an access network that communicates with wireless terminals over an air interface through one or more sectors. The base station may be used to convert received air frames to and from IP packets, acting as a router between the wireless terminal and the rest of the access network, which may include an Internet Protocol (IP) network. The base station may also coordinate attribute management of the air interface. For example, the base station may be a base station (BTS, Base Transceiver Station) in GSM or CDMA, a base station (NodeB) in WCDMA, or an evolved base station (NodeB or eNB or e-NodeB, evolutional Node) in LTE B), or it can also be a gNB in the 5G system, etc. There is no limitation in this embodiment of the present application.

The processing flow of the above method can be implemented by a software program, and the software program can be stored in a storage medium, and when the stored software program is called, the above method steps are executed.

As will be appreciated by those skilled in the art, the embodiments of the present application may be provided as a method, a system, or a computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application 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 application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. 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.

Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

A carrier phase measurement method, characterized in that the method comprises:

Phase hopping detection is performed for the valid subcarriers in the current OFDM symbol of the input baseband signal;

Determine the frequency domain dynamic feedback output value of the effective subcarrier according to the phase hopping detection result;

Based on the frequency domain dynamic feedback output value, phase correction is performed on the input baseband signal.
The method according to claim 1, wherein the effective subcarriers comprise subcarriers corresponding to the frequency domain of the positioning reference signal in the OFDM symbol.
The method according to claim 1, wherein the phase correction comprises:

For the current OFDM symbol of the input baseband signal, use the time-domain phase correction value to perform time-domain phase correction, and then perform time-frequency domain transformation;

Extracting the subcarriers corresponding to the positioning reference signal of the frequency domain position of the current OFDM symbol as valid subcarriers, and using the frequency domain phase correction value to perform frequency domain phase correction on the positioning reference signal of the current valid subcarriers;

Wherein, the frequency domain phase correction value and/or the time domain phase correction value are determined based on the frequency domain dynamic feedback output value.
The method according to claim 3, wherein the phase jump detection specifically comprises:

Compare the phase of the positioning reference signal of the current valid subcarrier after the frequency domain phase correction with the phase of the positioning reference signal of the valid subcarrier sent by the transmitting end, and use the frequency domain phase difference between the two as the corresponding current valid subcarrier. Frequency domain phase difference;

Based on the phase difference in the frequency domain, it is determined that the currently valid subcarrier belongs to one of the following three cases:

Case 1. Abnormal phase jump of a single subcarrier;

Case 2: Multiple subcarriers have abnormal continuous phase hopping;

Case 3: There is no abnormal jump in the subcarrier phase.
The method according to claim 4, is characterized in that, if the absolute value of the frequency domain phase difference corresponding to the current effective sub-carrier is greater than the first threshold value, then it is determined to belong to situation one;

If both of the following conditions are met, it is determined to belong to the second case:

The first condition: the absolute value of the frequency domain phase difference corresponding to the currently valid subcarrier is greater than the second threshold value;

The second condition: the absolute value of the accumulated frequency-domain phase difference is greater than the third threshold value; wherein, the accumulated frequency-domain phase difference is obtained in the following manner: the frequency-domain phase difference corresponding to the current effective subcarrier is the same as the previous When the sign bit of the frequency domain phase difference corresponding to an adjacent valid subcarrier is the same, the frequency domain phase difference is accumulated; the sign bit of the frequency domain phase difference corresponding to the current valid subcarrier and the frequency domain phase difference corresponding to the previous adjacent valid subcarrier When not, clear the accumulated frequency domain phase difference result;

If none of the above-mentioned conditions of Situation 1 and Situation 2 are met, it is determined to belong to Situation 3;

If the above conditions of Situation 1 and Situation 2 are met, it is finally determined to belong to Situation 2.
The method according to claim 4, wherein the determining the frequency domain dynamic feedback output value of the effective subcarrier according to the phase hopping detection result specifically includes:

Calculate the dynamic adjustment feedback coefficient of the current effective subcarrier;

The frequency domain dynamic feedback output value of the effective subcarrier is obtained by multiplying the frequency domain phase difference corresponding to the effective subcarrier by the dynamic adjustment feedback coefficient of the current effective subcarrier.
The method of claim 6, wherein:

For the third case: the dynamically adjusted feedback coefficient is the first feedback coefficient, and the first feedback coefficient is determined according to the time delay detected by the frequency domain loop of the previous OFDM symbol;

For the first case: the dynamic adjustment feedback coefficient is the first feedback coefficient multiplied by the preset first reduction coefficient;

For the second case: the dynamic adjustment feedback coefficient is the first feedback coefficient multiplied by the preset first reduction coefficient, and then multiplied by the preset second reduction coefficient.
The method according to claim 3, wherein the frequency domain phase correction value is determined by the following steps:

In the current OFDM symbol, the frequency domain dynamic feedback output values of the effective subcarriers before the current effective subcarrier are accumulated in the order of effective subcarriers, and the accumulation result is used as the frequency domain phase correction value of the current effective subcarrier.
The method according to claim 8, wherein the method further comprises:

Multiplying the frequency domain phase correction value of the preset effective subcarriers of the current OFDM symbol by the preset time domain feedback coefficient to obtain the time domain feedback value of the current OFDM symbol.
The method according to claim 9, wherein the time domain phase correction value is determined by the following steps:

The time domain feedback values of the OFDM symbols before the current OFDM symbol are accumulated in the order of OFDM symbols, and the accumulated result is used as the time domain phase correction value of the current OFDM symbol.
A carrier phase measurement device, characterized in that the device comprises:

memory for storing program instructions;

The processor is used for calling the program instructions stored in the memory, and executes according to the obtained program:

Phase hopping detection is performed for the valid subcarriers in the current OFDM symbol of the input baseband signal;

Determine the frequency domain dynamic feedback output value of the effective subcarrier according to the phase hopping detection result;

Based on the frequency domain dynamic feedback output value, phase correction is performed on the input baseband signal.
The apparatus according to claim 11, wherein the effective subcarriers comprise subcarriers corresponding to the frequency domain of the positioning reference signal in the OFDM symbol.
The apparatus of claim 11, wherein the phase correction comprises:

For the current OFDM symbol of the input baseband signal, use the time-domain phase correction value to perform time-domain phase correction, and then perform time-frequency domain transformation;

Extracting the subcarriers corresponding to the positioning reference signal of the frequency domain position of the current OFDM symbol as valid subcarriers, and using the frequency domain phase correction value to perform frequency domain phase correction on the positioning reference signal of the current valid subcarriers;

Wherein, the frequency domain phase correction value and/or the time domain phase correction value are determined based on the frequency domain dynamic feedback output value.
The device according to claim 13, wherein the phase jump detection specifically comprises:

Compare the phase of the positioning reference signal of the current valid subcarrier after the frequency domain phase correction with the phase of the positioning reference signal of the valid subcarrier sent by the transmitting end, and use the frequency domain phase difference between the two as the corresponding current valid subcarrier. Frequency domain phase difference;

Based on the phase difference in the frequency domain, it is determined that the currently valid subcarrier belongs to one of the following three cases:

Case 1. Abnormal phase jump of a single subcarrier;

Case 2: Multiple subcarriers have abnormal continuous phase hopping;

Case 3: There is no abnormal jump in the subcarrier phase.
The device according to claim 14, wherein, if the absolute value of the frequency domain phase difference corresponding to the current effective subcarrier is greater than the first threshold value, it is determined that the case belongs to the first case;

If both of the following conditions are met, it is determined to belong to the second case:

The first condition: the absolute value of the frequency domain phase difference corresponding to the currently valid subcarrier is greater than the second threshold value;

The second condition: the absolute value of the accumulated frequency-domain phase difference is greater than the third threshold value; wherein, the accumulated frequency-domain phase difference is obtained in the following manner: the frequency-domain phase difference corresponding to the current effective subcarrier is the same as the previous When the sign bit of the frequency domain phase difference corresponding to an adjacent valid subcarrier is the same, the frequency domain phase difference is accumulated; the sign bit of the frequency domain phase difference corresponding to the current valid subcarrier and the frequency domain phase difference corresponding to the previous adjacent valid subcarrier When not, clear the accumulated frequency domain phase difference result;

If none of the above-mentioned conditions of Situation 1 and Situation 2 are met, it is determined to belong to Situation 3;

If the above conditions of Situation 1 and Situation 2 are met, it is finally determined to belong to Situation 2.
The apparatus according to claim 14, wherein the determining the frequency domain dynamic feedback output value of the effective subcarrier according to the phase hopping detection result specifically includes:

Calculate the dynamic adjustment feedback coefficient of the current effective subcarrier;

The frequency domain dynamic feedback output value of the effective subcarrier is obtained by multiplying the frequency domain phase difference corresponding to the effective subcarrier by the dynamic adjustment feedback coefficient of the current effective subcarrier.
The apparatus of claim 16, wherein:

For the third case: the dynamically adjusted feedback coefficient is the first feedback coefficient, and the first feedback coefficient is determined according to the time delay detected by the frequency domain loop of the previous OFDM symbol;

For the first case: the dynamic adjustment feedback coefficient is the first feedback coefficient multiplied by the preset first reduction coefficient;

For the second case: the dynamic adjustment feedback coefficient is the first feedback coefficient multiplied by the preset first reduction coefficient, and then multiplied by the preset second reduction coefficient.
The apparatus according to claim 13, wherein the processor determines the frequency domain phase correction value through the following steps:

In the current OFDM symbol, the frequency domain dynamic feedback output values of the effective subcarriers before the current effective subcarrier are accumulated in the order of effective subcarriers, and the accumulation result is used as the frequency domain phase correction value of the current effective subcarrier.
The apparatus of claim 18, wherein the processor is further configured to:

Multiplying the frequency domain phase correction value of the preset effective subcarriers of the current OFDM symbol by the preset time domain feedback coefficient to obtain the time domain feedback value of the current OFDM symbol.
The apparatus according to claim 19, wherein the processor determines the time-domain phase correction value through the following steps:

The time domain feedback values of the OFDM symbols before the current OFDM symbol are accumulated in the order of OFDM symbols, and the accumulated result is used as the time domain phase correction value of the current OFDM symbol.
A carrier phase measurement device, characterized in that the device comprises:

a first unit, configured to perform phase hopping detection for valid subcarriers in the current OFDM symbol of the input baseband signal;

a second unit, configured to determine the frequency domain dynamic feedback output value of the effective subcarrier according to the phase hopping detection result;

The third unit is configured to perform phase correction on the input baseband signal based on the frequency domain dynamic feedback output value.
A computer storage medium, characterized in that the computer storage medium stores computer-executable instructions, and the computer-executable instructions are used to cause the computer to execute the method of any one of claims 1 to 10.