WO2017097053A1

WO2017097053A1 - Method and apparatus for estimating timing deviation, and terminal

Info

Publication number: WO2017097053A1
Application number: PCT/CN2016/103625
Authority: WO
Inventors: 熊芳
Original assignee: 电信科学技术研究院
Priority date: 2015-12-10
Filing date: 2016-10-27
Publication date: 2017-06-15
Also published as: CN106878205A; CN106878205B

Abstract

A method and apparatus for estimating a timing deviation and a terminal, for use in resolving the problems of effective diameter threshold calculation and neighboring cell timing measurement affected due to possible window exceeding of the effective diameter in a case in which the time of a neighboring cell greatly precedes or falls behind this cell. The method comprises: determining a time-domain channel estimation result according to CRS of a neighboring cell, determining a first effective diameter threshold according to the time-domain channel estimation result, a first noise window power and a peak power, and determining a first timing deviation value between a current cell and the neighboring cell according to the first effective diameter threshold; adjusting a timing deviation of the time-domain channel estimation result according to the first timing deviation value, and determining a second effective diameter threshold according to a second noise wind power of the adjusted time-domain channel estimation result and the peak power; and determining a second timing deviation value between the current cell and the neighboring cell according to the second effective diameter threshold, and determining the timing deviation between the current cell and the neighboring cell according to the first timing deviation value and the second timing deviation value.

Description

Method, device and terminal for estimating timing deviation

The present application claims priority to Chinese Patent Application No. 201510918097.9, filed on Dec. 10, 2015, the entire disclosure of which is incorporated herein by reference. In this application.

Technical field

The present application relates to the field of communications technologies, and in particular, to a timing offset estimation method, apparatus, and terminal.

Background technique

Further enhanced Inter-cell Interference Coordination (FICIC) technology needs to cope with neighbor-cell reference signals (CRSs, also referred to as cell-specific reference signals) and/or physics that occur in heterogeneous scenarios. The strong interference of the physical broadcast channel (PBCH) to the local cell (that is, the cell where the terminal is located), such as a macro base station-pico base station (also called macro-pico) deployment scenario or a macro base station-home base station (also called macro-femto) The deployment scenario, therefore, the terminal (UE) needs to perform interference cancellation on the CRS and/or PBCH.

In general, there is a certain relative deviation between the time when the interfering cell arrives at the UE and the time when the cell arrives at the UE. The frequency offset also has a certain relative deviation. The relative delay deviation may be in the range of [-3, 3] microseconds (us). Within, the relative frequency offset may range from [-300,300] Hertz (Hz). Generally, the UE uses only one Fast Fourier Transformation (FFT) operation unit in the time-frequency conversion. Therefore, in order to ensure the demodulation performance of the current cell, the UE can only set the timing in the time domain based on the received signal of the local cell. The windowing position, that is, it is impossible to track the timing of the neighboring cell to perform real-time synchronization of the neighboring cell. According to the timing of receiving the signal and performing channel estimation on the neighboring cell, it is necessary to estimate the delay spread of the neighboring cell to perform frequency domain filtering.

According to the behavior example of Long Term Evolution (LTE), as shown in FIG. 1, the existing delay spread estimation algorithm is described as follows: the downlink pilot transmission sequence is known as S, and the received signal is Y. The spatial frequency domain channel is H+n, where H represents the impulse response of the wireless fading channel, and n represents Gaussian white noise, then Y=(H+n)·S is satisfied, so that the frequency domain channel estimation can be estimated as:

The frequency domain channel estimation is transformed into the time domain for delay spread estimation, as follows: the frequency domain channel is transformed into the time domain, and the position of the maximum path of the useful signal delay is determined according to the Cyclic Prefix (CP) length or the prior information. The time domain noise path and the maximum path without the useful signal power are taken out, the noise power P _noise and the peak power P _{max are} calculated, and the effective path threshold is determined by setting the peak factor and the noise factor, thereby obtaining the effective path search space. Extended extension value.

Wherein, the noise factor and the crest factor can be set according to empirical values, and the effective path threshold is expressed as: Γ = (P _noise · β _noise , P _max · β _max ), where β _noise represents a noise threshold, which is noise power and noise The product of the factors, β _max represents the peak threshold, which is the product of the peak power and the crest factor. The method of setting the noise window according to the length of the CP is: calculating the position of the noise window by using the CP length as the time extension of the maximum delay time in the system. CP provides protection T _S N is the number of interval CP _CP at different bandwidths, T _S denotes a sampling interval in the LTE system, FFT points is N _FFT, the number of subcarriers N _SC, if the pilot frequency domain transformed to the corresponding When the FFT length in the time domain uses N _SC /6, the time domain position of the maximum delay time can be expressed as:

Considering that the Inverse Discrete Fourier Transform (IDFT) transform transforms the frequency domain into the time domain, power leakage of the signal may occur, and the N _NB path in the N _FFT is retained, and the range of the last effective path is retained. For [N _FFT - N _leak : N-1, 0: N _τ ], the noise window is [N _τ : N _FFT - N _leak ].

If the neighboring cell timing and the cell have a large advance or lag, it may cause an effective path window, that is, the search space containing the effective path and the effective path in the noise window is inaccurate, which will directly affect the calculation of the effective path threshold, and thus affect Neighbor cell timing measurement.

Summary of the invention

An embodiment of the present application provides a method, a device, and a terminal for estimating a timing offset, which are used to directly affect an effective path threshold when a neighboring cell timing and a large early or late phase of the cell may occur, which may cause an effective path window. The calculation, which in turn affects the timing measurement of neighboring cells.

The specific technical solutions provided by the embodiments of the present application are as follows:

The embodiment of the present application provides a timing offset estimation method, including:

Determining a time domain channel estimation result according to a channel estimation of a common reference signal CRS of a neighboring cell of the current cell, and determining a first noise window power and a peak power of the time domain channel estimation result;

Determining a first effective path threshold according to the first noise window power and the peak power, and determining a first timing deviation between a current cell and the neighboring cell according to the time domain channel estimation result and the first effective path threshold value;

Adjusting a timing offset of the time domain channel estimation result according to the first timing offset value, determining a second noise window power of the adjusted time domain channel estimation result, according to the second noise window power and the peak value The power determines a second effective path threshold;

Performing on the tap search space according to the adjusted time domain channel estimation result and the second effective path threshold Searching for a second timing offset value of the current cell and the neighboring cell, and determining a timing offset between the current cell and the neighboring cell according to the first timing offset value and the second timing offset value.

In a possible implementation manner, the method further includes:

And searching for the tap search space to determine a delay spread value of the current cell and the neighboring cell according to the adjusted time domain channel estimation result, the second effective path threshold, and the timing offset.

In a possible implementation manner, determining channel time channel estimation results by performing channel estimation according to a common reference signal CRS of a neighboring cell of the current cell, including:

Obtaining a frequency domain channel estimation result according to the least squares estimation of the CRS of the neighboring cell, performing inverse discrete Fourier transform on the frequency domain channel estimation result, to obtain the time domain channel estimation result.

In a possible implementation manner, determining a first noise window power and a peak power of the time domain channel estimation result, including:

Calculating a square of a modulus of a time domain channel estimation result for each column of pilots of each port in the time domain channel estimation result, expressed as:

among them,

Indicates the number of port p

The time domain channel estimation result of the column pilot, r represents the receiving antenna number index, and N _FFT represents the FFT point number;

Determining, according to a square of a modulus of a time domain channel estimation result of each column pilot of each port in the time domain channel estimation result, the first noise window power is:

Where N _τ represents the time domain position of the maximum path of the delay, and N _leak represents the number of paths of the reserved N _FFT ;

Determining, according to a square of a modulus of a time domain channel estimation result of each column of pilots of each port in the time domain channel estimation result, the peak power is:

In a possible implementation, determining the first effective path threshold according to the first noise window power and the peak power includes:

Calculating a product of the first noise window power and a first coefficient to obtain a first product, and calculating a product of the peak power and a second coefficient to obtain a second product;

Determining a maximum value of the first product and the second product, and determining that the maximum value is greater than or equal to the peak power, determining that the first effective path threshold is the peak power, and determining the maximum The value is less than the peak power, and the first effective path threshold is determined to be the maximum value.

In a possible implementation manner, determining, according to the time domain channel estimation result and the first effective path threshold, a first timing offset value of the current cell and the neighboring cell, including:

Determining a first timing offset value of the current cell and the neighboring cell:

among them,

P represents the total number of ports, and R represents the total number of receiving antennas, where Γ ^{(r, p)} represents the first effective path threshold.

In a possible implementation, the timing offset of the time domain channel estimation result is adjusted according to the first timing offset value, including:

And shifting the time domain tap corresponding to the first timing offset in the time domain channel estimation result to the zeroth time domain tap, and sequentially shifting each time domain tap in the time domain channel estimation result to obtain the adjusted The time domain channel estimation result is:

Where k=0,...,N _FFT -1, N _FFT represents the number of FFT points, and τ ₁ represents the first timing offset value,

Indicates the number of port p

The time domain channel estimation result of the column pilot.

In a possible implementation, determining the second effective path threshold according to the second noise window power and the peak power includes:

Calculating a product of the second noise window power and a third coefficient to obtain a third product, and calculating a product of the peak power and the fourth coefficient to obtain a fourth product;

Determining a maximum value of the third product and the fourth product, and determining that the maximum value is greater than or equal to the peak power, determining that the second effective path threshold is the peak power, and determining the maximum The value is less than the peak power, and the second effective path threshold is determined to be the maximum value.

In a possible implementation, the tap search space is searched according to the adjusted time domain channel estimation result, the second effective path threshold, and the timing offset to determine a delay spread value of the current cell and the neighboring cell. ,include:

Determining the first path position according to the adjusted time domain channel estimation result and the second effective path threshold:

i=-N _leak ,...,N _τ ,N _τ represents the time domain position of the maximum delay time, r represents the receiving antenna number index, N _FFT represents the number of FFT points, and p represents the port number.

Indicates the index number of the column where the pilot of port p is located.

Representing a second effective path threshold, N _leak represents the number of paths of the reserved N _FFT , (τ' ₁ + τ ₁ ) represents the timing deviation, τ ₁ represents the first timing deviation, and τ' ₁ represents the Second timing deviation;

Determine the position of the trailing diameter as:

Where i=-N _leak ,...,N _τ ,r denotes the receiving antenna number index, N _FFT denotes the number of FFT points, and p denotes the port number,

Indicates the index number of the column where the pilot of port p is located.

Representing a second effective path threshold, N _leak represents the number of paths of the retained N _FFT , (τ' ₁ + τ ₁ ) represents the timing deviation, τ ₁ represents the first timing deviation, and τ' ₁ represents the Second timing deviation;

Determining a result of subtracting the position of the trailing path from the position of the trailing path, and determining the result as a delay spread value of a current cell and the neighboring cell.

A timing deviation estimating apparatus is further provided in the embodiment of the present application, including:

a first processing module, configured to determine a time domain channel estimation result by using a common reference signal CRS of a neighboring cell of the current cell, and determine a first noise window power and a peak power of the time domain channel estimation result;

a second processing module, configured to determine a first effective path threshold according to the first noise window power and the peak power, and determine, according to the time domain channel estimation result and the first effective path threshold, a current cell and the a first timing offset value of the neighboring cell;

a third processing module, configured to adjust, according to the first timing offset value, a timing offset of the time domain channel estimation result, to determine a second noise window power of the adjusted time domain channel estimation result, according to the second The noise window power and the peak power determine a second effective path threshold;

a fourth processing module, configured to perform a search on the tap search space to determine a second timing offset value of the current cell and the neighboring cell according to the adjusted time domain channel estimation result and the second effective path threshold, according to the The first timing offset value and the second timing offset value determine a timing offset between the current cell and the neighboring cell.

In a possible implementation, the fifth processing module is further configured to:

In a possible implementation manner, the first processing module is specifically configured to:

among them,

Indicates the number of port p

In a possible implementation manner, the second processing module is specifically configured to:

among them,

In a possible implementation manner, the third processing module is specifically configured to:

Indicates the number of port p

The time domain channel estimation result of the column pilot.

In a possible implementation manner, the fifth processing module is specifically configured to:

Indicates the index number of the column where the pilot of port p is located.

Determine the position of the trailing diameter as:

Indicates the index number of the column where the pilot of port p is located.

The embodiment of the present application further provides a terminal, which mainly includes a processor and a memory, wherein the memory stores a preset program, and the processor is configured to read a program saved in the memory, and execute the following process according to the program:

And performing a search on the tap search space to determine a second timing offset value of the current cell and the neighboring cell according to the adjusted time domain channel estimation result and the second effective path threshold, according to the first timing offset value and The second timing offset value determines a timing offset between the current cell and the neighboring cell.

In a possible implementation, the processor searches for the tap search space according to the adjusted time domain channel estimation result, the second effective path threshold, and the timing offset to determine a delay between the current cell and the neighboring cell. Extended value.

In a possible implementation manner, the processor obtains a frequency domain channel estimation result according to the least squares estimation of the CRS of the neighboring cell, and performs inverse discrete Fourier transform on the frequency domain channel estimation result to obtain the time domain channel estimation. result.

In a possible implementation manner, the processor determines a first noise window power and a peak power of the time domain channel estimation result, where the specific process is:

among them,

Indicates the number of port p

In a possible implementation, the processor calculates a product of the first noise window power and the first coefficient to obtain a first multiplication Product, and calculating a product of the peak power and the second coefficient to obtain a second product;

Determining a maximum value of the first product and the second product. If the maximum value is greater than or equal to the peak power, determining that the first effective path threshold is the peak power, and if the maximum value is determined to be less than the peak power, The first effective path threshold is determined to be the maximum value.

In a possible implementation manner, the processor determines that the first timing offset value of the current cell and the neighboring cell is:

among them,

In a possible implementation manner, the processor adjusts a timing offset of the time domain channel estimation result according to the first timing offset value, and the process is:

Indicates the number of port p

The time domain channel estimation result of the column pilot.

In a possible implementation, the process of determining the second effective path threshold by the processor is:

Calculating a product of the second noise window power and a third coefficient to obtain a third product, and calculating a product of the peak power and the fourth coefficient to obtain a fourth product; selecting the third product and the fourth product a maximum value, if it is determined that the maximum value is greater than or equal to the peak power, determining that the second effective path threshold is the peak power, and if the maximum value is determined to be smaller than the peak power, determining the second effective path The threshold is the maximum value.

In a possible implementation manner, the processor determines, according to the adjusted time domain channel estimation result and the second effective path threshold, that the first path position is:

Indicates the index number of the column where the pilot of port p is located.

Indicates a second effective path threshold, N _leak represents the number of paths of the reserved N _FFT , (τ' ₁ + τ ₁ ) represents the timing deviation, τ ₁ represents the first timing deviation, and τ' ₁ represents the Second timing deviation;

Determine the position of the trailing diameter as:

Indicates the index number of the column where the pilot of port p is located.

The terminal provided by the embodiment of the present application includes: a processor and a memory, wherein the memory stores a preset program, and the processor is configured to read a program saved in the memory, and execute the following process according to the program;

Based on the foregoing technical solution, in the embodiment of the present application, when there is a delay between the neighboring cell and the current cell, the channel estimation result is obtained according to the CRS of the neighboring cell, and the first time channel estimation result is determined. After determining the first effective path threshold according to the first noise window power and the peak power, the first effective path threshold is used for coarse synchronization to obtain a first timing deviation value for performing coarse synchronization, and the first timing deviation value is adopted. Performing coarse synchronization adjustment on the timing deviation of the time domain channel estimation result, determining the second noise window power of the adjusted time domain channel estimation result, determining the second effective path threshold according to the second noise window power and the peak power, and adopting the second effective The path threshold searches for the tap search space to determine the second timing offset value of the precise synchronization, so that the neighboring cell timing may be advanced or delayed in time with the local cell, which may cause the effective path window, and the coarse timing synchronization time Domain channel estimation The line synchronization is adjusted so that the effective path does not fall into the noise window, and an effective effective path threshold is obtained, thereby obtaining relatively accurate timing deviation estimation measurement and delay extension measurement.

DRAWINGS

1 is a schematic diagram of an implementation process of an existing delay spread estimation algorithm;

2 is a schematic flowchart of a method for estimating a timing offset in an embodiment of the present application;

3 is a schematic structural diagram of a timing offset estimation apparatus according to an embodiment of the present application;

FIG. 4 is a schematic structural diagram of a terminal in an embodiment of the present application.

detailed description

The present invention will be further described in detail with reference to the accompanying drawings, in which FIG. 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.

In the embodiment of the present application, as shown in FIG. 2, the detailed method flow of the timing deviation estimation is as follows:

Step 201: Determine a time domain channel estimation result according to a CRS of a neighboring cell of the current cell, and determine a first noise window power and a peak power of the time domain channel estimation result.

Specifically, determining a time domain channel estimation result by performing channel estimation according to a CRS of a neighboring cell of the current cell, specifically:

The frequency domain channel estimation result is obtained by performing Least Square (LS) estimation according to the CRS of the neighboring cell, and the frequency domain channel estimation result is expressed as formula (1):

Where r is the receiving antenna number index and p is the antenna port number index.

Indicates the number of pilot columns of port p, assuming that the total number of receiving antennas is R and the total number of ports is P;

Frequency domain channel estimation results

Perform discrete Fourier transform to obtain time domain channel estimation results

Expressed as formula (2):

among them,

Indicates the number of port p

The result of the time domain channel estimation of the column pilot, N _FFT represents the number of FFT points, and r represents the receiving antenna number index.

Specifically, the specific process of determining the first noise window power and the peak power of the time domain channel estimation result is as follows:

Calculating the square of the modulus of the time domain channel estimation result for each column of pilots for each port in the time domain channel estimation result, expressed as equation (3):

among them,

Indicates the number of port p

The first noise window power is determined according to the square of the modulus of the time domain channel estimation result of each column pilot of each port in the time domain channel estimation result, as shown in the formula (4):

The peak power is determined according to the square of the mode of the time domain channel estimation result of each column pilot of each port in the time domain channel estimation result, as shown in the formula (5):

Step 202: Determine a first effective path threshold according to the first noise window power and the peak power, and determine a first timing offset value of the current cell and the neighboring cell according to the time domain channel estimation result and the first effective path threshold.

Specifically, the process of determining the first effective path threshold is: calculating a product of the first noise window power and the first coefficient to obtain a first product, and calculating a product of the peak power and the second coefficient to obtain a second product; selecting the first product and a maximum value of the second product, if it is determined that the maximum value is greater than or equal to the peak power, determining that the first effective path threshold is the peak power, and if the maximum value is determined to be less than the peak power, determining that the first effective path threshold is the maximum value.

Wherein, the first coefficient and the second coefficient can be determined by simulation.

The first effective path threshold is expressed by equation (6) as:

among them,

Indicates the first noise window power,

Indicates peak power, β _noise represents the first coefficient, and β _max represents the second coefficient. If the first effective path threshold determined according to formula (6) is satisfied

Then re-assign the first effective path threshold:

Specifically, determining, according to the time domain channel estimation result and the first effective path threshold, the first of the current cell and the neighboring cell Timing deviation value, the specific process is:

The first timing deviation of the current cell and the neighboring cell is determined as shown in the formula (7):

among them,

i=-N _leak ,..., N _τ , P represents the total number of ports, and R represents the total number of receiving antennas, where Γ ^{(r, p)} represents the first effective path threshold. among them,

The physical meaning is to find in the search range of i=-N _leak ,...,N _τ

The smallest index greater than or equal to Γ ^{(r, p)} .

Step 203: Adjust a timing offset of the time domain channel estimation result according to the first timing offset value, determine a second noise window power of the adjusted time domain channel estimation result, and determine a second effective according to the second noise window power and the peak power. Path threshold.

The value range of the noise window is preset.

Specifically, the timing offset of the time domain channel estimation result is adjusted according to the first timing offset value, specifically:

The time domain tap corresponding to the first timing offset is moved to the zeroth time domain tap to obtain the second time domain channel estimation result as shown in the formula (8):

Indicates the number of port p

The time domain channel estimation result of the column pilot.

According to the formula (4) and formula (5), according to the adjusted time domain channel estimation result, the noise power is calculated for each port of each receiving antenna in the noise window [N _τ : N _FFT - N _leak ]. Second noise window power

Set the third coefficient to

Set the fourth coefficient to

Wherein, the third coefficient and the fourth coefficient can be determined by simulation.

Specifically, the process of determining the second effective path threshold is: calculating a product of the second noise window power and the third coefficient to obtain a third product, and calculating a product of the peak power and the fourth coefficient to obtain a fourth product;

Selecting a maximum value in the third product and the fourth product. If it is determined that the maximum value is greater than or equal to the peak power, determining that the second effective path threshold is the peak power, and determining that the maximum value is less than the peak power, determining the second effective path The threshold is the maximum.

The second effective path threshold is expressed by the formula (9) as:

If the second effective path threshold determined according to formula (9) is satisfied

Then re-assign the second effective path threshold:

Step 204: Perform a search on the tap search space to determine a second timing offset value of the current cell and the neighboring cell according to the adjusted time domain channel estimation result and the second effective path threshold, according to the first timing offset value and the second timing offset value. The timing offset between the current cell and the neighboring cell is determined.

The value range of the tap search space is preset. Specifically, the value range of the tap search space is complementary to the value range of the noise window, and the total length of the search space is assumed to be N _FFT if some points in the search space Set to noise space, the other part is the tap search space.

Specifically, after determining the second effective path threshold, searching the tap search space [N _FFT -N _leak :N _FFT -1,0:N _τ ] to obtain a second timing offset value τ1' of the current cell and the neighboring cell, Equation (10) and formula (11) are expressed as:

Where i=-N _leak ,..., N _τ , P represents the total number of ports, and R represents the total number of receiving antennas, where

Indicates the second effective path threshold. The peak power of the adjusted time domain channel estimation result is the same as the peak power of the time domain channel estimation result before the adjustment.

Specifically, the sum of the first timing offset value and the second timing offset value is calculated, and the obtained sum value is determined as a timing offset between the current cell and the neighboring cell.

In the implementation, the tap search space may be searched according to the adjusted time domain channel estimation result, the second effective path threshold, and the determined timing offset to determine a delay spread value of the current cell and the neighboring cell.

Specifically, according to the adjusted time domain channel estimation result and the second effective path threshold, determining the first path position is represented by formula (12):

Where i=-N _leak ,...,N _τ ,N _τ represents the time domain position of the maximum delay time, r represents the receiving antenna number index, N _FFT represents the number of FFT points, and p represents the port number.

Indicates the index number of the column where the pilot of port p is located.

The second effective path threshold is expressed, N _leak represents the number of paths of the reserved N _FFT , (τ' ₁ + τ ₁ ) represents the timing deviation, τ ₁ represents the first timing deviation, and τ ' ₁ represents the second timing deviation;

Determine the position of the trailing diameter as shown in equation (13):

Indicates the index number of the column where the pilot of port p is located.

Representing the second effective path threshold, N _leak represents the number of paths of the reserved N _FFT , (τ' ₁ + τ ₁ ) represents the timing deviation, τ ₁ represents the first timing deviation, and τ ' ₁ represents the second timing deviation;

The result obtained by subtracting the position of the trailing path from the position of the trailing path is determined, and the result is determined as the delay spread value of the current cell and the neighboring cell.

Among them, in formula (12) and formula (13)

among them,

Indicates the number of port p

The adjusted time domain channel estimation result of the column pilot, r represents the receiving antenna number index, and N _FFT represents the FFT point number.

The calculation process of the timing offset and the delay spread provided in the embodiment of the present application is exemplified by two specific embodiments.

In the LTE FEICIC macro-pico deployment scenario, there is a PCO cell B with a bandwidth of 10 MHz and a Pico cell B with a bandwidth of 10 MHz. The UE is at the edge of the Pico cell and is strongly interfered by the CRS of the macro cell. The delay of the cell arriving at the UE and the B cell reaching the UE is 3us ahead. The specific implementation steps are as follows:

Step 1: Perform LS estimation on the CRS of the neighboring cell A to obtain a frequency domain channel estimation result.

among them,

r represents the receiving antenna number index, and p represents the antenna port number index.

Indicates the number of pilot columns for port p. Assume that the total number of receiving antennas is R and the total number of ports is P.

Step 2, estimating the frequency domain channel

Perform IDFT transform to obtain time domain channel estimation results

Expressed as

among them,

Indicates the number of port p

The result of the time domain channel estimation of the column pilot, N _FFT represents the number of FFT points, and r represents the received antenna number index, where N _FFT = 256.

Step 3, according to

Calculate the total power of the first noise window

Peak power

among them,

Indicates the number of port p

The time domain channel estimation result of the column pilot, r represents the receiving antenna number index, and N _FFT represents the FFT point number. N _τ represents the time domain position of the maximum path of the delay, and N _leak represents the number of paths of the reserved N _FFT .

among them,

In step 4, coarse timing synchronization is performed to obtain a first timing offset value τ ₁ .

Specifically, setting a first effective path threshold

among them,

Indicates the first noise window power,

Representing the first peak power, β _noise represents the first coefficient, and β _max represents the second coefficient. The β _max setting value is greater than β _noise , so that the first effective path threshold is relatively high, and the first path power is the largest under the general system, and the effective path threshold is higher to ensure the relative accuracy of the timing estimation. The β _max can be determined by simulation. If the first effective path threshold determined according to the formula satisfies

Then re-assign the first effective path threshold:

The first timing offset value τ _{1 is} expressed as:

among them,

Step 5, calculating a second effective path threshold according to the first timing offset value τ ₁

Specifically, adjusted according to τ ₁

The physical meaning is to move the time domain tap corresponding to the coarse timing synchronization estimation to the position of the 0th time domain tap.

Finally, the adjusted time domain channel estimation result is obtained.

details as follows:

Indicates the number of port p

The time domain channel estimation result of the column pilot.

Setting

with

For each receiving antenna, for each port

Calculate the noise power in the noise window [N _τ :N _FFT -N _leak ]

According to each receiving antenna, each port

Peak power

And noise power

determine

among them,

with

Can be determined by simulation. If the second effective path threshold determined according to the formula satisfies

Then re-assign the second effective path threshold:

Step 6. Perform timing synchronization measurement and delay extension measurement on the time domain channel estimation.

Specifically, the tap search space [N _FFT - N _leak : N _FFT -1, 0: N _τ ] is searched to obtain a timing synchronization measurement value or a delay spread measurement value, wherein the timing deviation measurement value and the delay spread are obtained. The measured values can be set separately

with

To meet different needs.

Specifically, the timing deviation measurement value is expressed as τ' ₁ + τ ₁ , and the obtaining process of τ' ₁ is:

among them,

P represents the total number of ports, and R represents the total number of receiving antennas, where

Indicates the second effective path threshold. among them,

Specifically, the process of obtaining the delay spread measurement value is:

Determine the first path position as

Where i=-N _leak ,...,N _τ ,N _τ represents the time domain position of the maximum path of the delay;

Determine the position of the trailing diameter as

Where i=-N _leak ,...,N _τ ;

The result obtained by subtracting the position of the trailing path from the position of the trailing path is the delay spread value of the current cell and the neighboring cell.

In the LTE FEICIC macro-pico deployment scenario, there is a PIMS cell B with a bandwidth of 10 MHz and a Pico cell B with a bandwidth of 10 MHz. The UE is at the edge of the Pico cell and is strongly interfered by the CRS of the macro cell. The delay of the cell arriving at the UE and the B cell to the UE is delayed by 3 us. The specific implementation is the same as the description of Step 1 to Step 6 in the first embodiment, and details are not described herein.

Based on the same application concept, the timing deviation estimation apparatus is also provided in the embodiment of the present application. For the specific implementation of the apparatus, refer to the description of the foregoing method embodiment, and the repeated description is not repeated, as shown in FIG. include:

The first processing module 301 is configured to determine, according to a common reference signal CRS of a neighboring cell of the current cell, a channel estimation result, and determine a first noise window power and a peak power of the time domain channel estimation result;

The second processing module 302 is configured to determine a first effective path threshold according to the first noise window power and the peak power, and determine a current cell and a location according to the time domain channel estimation result and the first effective path threshold. Determining a first timing offset value of the neighboring cell;

The third processing module 303 is configured to adjust, according to the first timing offset value, a timing offset of the time domain channel estimation result, and determine a second noise window power of the adjusted time domain channel estimation result, according to the The second noise window power and the peak power determine a second effective path threshold;

The fourth processing module 304 is configured to perform a search on the tap search space to determine a second timing offset value of the current cell and the neighboring cell according to the adjusted time domain channel estimation result and the second effective path threshold, according to The first timing offset value and the second timing offset value determine a timing offset between a current cell and the neighboring cell.

In an implementation, a fifth processing module 305 is further included for:

In an implementation, the first processing module is specifically configured to:

among them,

Indicates the number of port p

In an implementation, the second processing module is specifically configured to:

among them,

In an implementation, the third processing module is specifically configured to:

Indicates the number of port p

The time domain channel estimation result of the column pilot.

In an implementation, the fifth processing module is specifically configured to:

Indicates the index number of the column where the pilot of port p is located.

Determine the position of the trailing diameter as:

Indicates the index number of the column where the pilot of port p is located.

Based on the same application concept, a terminal is also provided in the embodiment of the present application. For the specific implementation of the terminal, refer to the detailed description of the foregoing method embodiment, and the repeated description is not repeated. As shown in FIG. 4, the terminal mainly includes processing. 401 And a memory 402, wherein the memory 402 stores a preset program, and the processor 401 is configured to read a program saved in the memory 402, and execute the following process according to the program:

In an implementation, the processor searches for the tap search space according to the adjusted time domain channel estimation result, the second effective path threshold, and the timing offset to determine a delay spread value of the current cell and the neighboring cell.

In an implementation, the processor obtains a frequency domain channel estimation result according to the least squares estimation of the CRS of the neighboring cell, and performs inverse discrete Fourier transform on the frequency domain channel estimation result to obtain the time domain channel estimation result.

In an implementation, the processor determines a first noise window power and a peak power of the time domain channel estimation result, where the specific process is:

among them,

Indicates the number of port p

In an implementation, the processor calculates a product of the first noise window power and the first coefficient to obtain a first product, and calculates a product of the peak power and the second coefficient to obtain a second product;

In an implementation, the processor determines that the first timing offset value of the current cell and the neighboring cell is:

among them,

In an implementation, the processor adjusts a timing offset of the time domain channel estimation result according to the first timing offset value, and the process is:

Indicates the number of port p

The time domain channel estimation result of the column pilot.

In the implementation, the process of determining the second effective path threshold by the processor is:

In the implementation, the processor determines, according to the adjusted time domain channel estimation result and the second effective path threshold, that the first path position is:

Indicates the index number of the column where the pilot of port p is located.

Determine the position of the trailing diameter as:

Indicates the index number of the column where the pilot of port p is located.

Wherein, the processor and the memory are connected by a bus, and the bus architecture may include any number of interconnected buses and bridges, specifically linked by one or more processors represented by the processor and various circuits of the memory represented by the memory. The bus architecture can also link various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and, therefore, will not be further described herein. The bus interface provides an interface. The processor is responsible for managing the bus architecture and the usual processing, and the memory can store the data that the processor uses when performing operations.

Based on the foregoing technical solution, in the embodiment of the present application, when there is a delay between the neighboring cell and the current cell, the channel estimation result is obtained according to the CRS of the neighboring cell, and the first time channel estimation result is determined. After determining the first effective path threshold according to the first noise window power and the peak power, the first effective path threshold is used for coarse synchronization to obtain a first timing deviation value for performing coarse synchronization, and the first timing deviation value is adopted. Performing coarse synchronization adjustment on the timing deviation of the time domain channel estimation result, determining the second noise window power of the adjusted time domain channel estimation result, determining the second effective path threshold according to the second noise window power and the peak power, and adopting the second effective The path threshold searches for the tap search space to determine the second timing offset value of the precise synchronization, so that the neighboring cell timing may be advanced or delayed in time with the local cell, which may cause the effective path window, and the coarse timing synchronization time The domain channel estimation is adjusted synchronously so that the effective path does not fall into the noise window, thereby obtaining effective Effective threshold diameter, thereby obtaining relatively accurate measurement of the timing offset estimation and the measured delay spread.

Those skilled in the art will appreciate that embodiments of the present application can be provided as a method, system, or computer program product. Thus, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment in combination of software and hardware. Moreover, the application can take the form of a computer program product embodied on one or more computer usable storage media (including but not limited to disk storage and optical storage, etc.) in which computer usable program code is embodied. formula.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the present application. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

It will be apparent to those skilled in the art that various modifications and changes can be made in the present application without departing from the spirit and scope of the application. Thus, it is intended that the present invention cover the modifications and variations of the present invention.

Claims

A timing deviation estimation method, comprising:

Determining a time domain channel estimation result according to a channel estimation of a common reference signal CRS of a neighboring cell of the current cell, and determining a first noise window power and a peak power of the time domain channel estimation result;

Determining a first effective path threshold according to the first noise window power and the peak power, and determining a first timing deviation between a current cell and the neighboring cell according to the time domain channel estimation result and the first effective path threshold value;

Adjusting a timing offset of the time domain channel estimation result according to the first timing offset value, determining a second noise window power of the adjusted time domain channel estimation result, according to the second noise window power and the peak value The power determines a second effective path threshold;

And performing a search on the tap search space to determine a second timing offset value of the current cell and the neighboring cell according to the adjusted time domain channel estimation result and the second effective path threshold, according to the first timing offset value and The second timing offset value determines a timing offset between the current cell and the neighboring cell.
The method of claim 1 wherein the method further comprises:

And searching for the tap search space to determine a delay spread value of the current cell and the neighboring cell according to the adjusted time domain channel estimation result, the second effective path threshold, and the timing offset.
The method according to claim 1 or 2, wherein determining the time domain channel estimation result by performing channel estimation according to the CRS of the neighboring cell of the current cell comprises:

Obtaining a frequency domain channel estimation result according to the least squares estimation of the CRS of the neighboring cell, performing inverse discrete Fourier transform on the frequency domain channel estimation result, to obtain the time domain channel estimation result.
The method according to claim 1 or 2, wherein determining the first noise window power and the peak power of the time domain channel estimation result comprises:

Calculating a square of a modulus of a time domain channel estimation result for each column of pilots of each port in the time domain channel estimation result, expressed as:
among them,
Indicates the number of port p
The time domain channel estimation result of the column pilot, r represents the receiving antenna number index, and N FFT represents the FFT point number;

Determining, according to a square of a modulus of a time domain channel estimation result of each column pilot of each port in the time domain channel estimation result, the first noise window power is:
Where N τ represents the time domain position of the maximum path of the delay, and N leak represents the number of paths of the reserved N FFT ;

Determining, according to a square of a modulus of a time domain channel estimation result of each column of pilots of each port in the time domain channel estimation result, the peak power is:
The method of claim 4, wherein determining the first effective path threshold based on the first noise window power and the peak power comprises:

Calculating a product of the first noise window power and a first coefficient to obtain a first product, and calculating a product of the peak power and a second coefficient to obtain a second product;

Determining a maximum value of the first product and the second product, and determining that the maximum value is greater than or equal to the peak power, determining that the first effective path threshold is the peak power, and determining the maximum The value is less than the peak power, and the first effective path threshold is determined to be the maximum value.
The method according to claim 5, wherein determining a first timing offset value of the current cell and the neighboring cell according to the time domain channel estimation result and the first effective path threshold comprises:

Determining a first timing offset value of the current cell and the neighboring cell:

among them,
P represents the total number of ports, and R represents the total number of receiving antennas, where Γ (r, p) represents the first effective path threshold.
The method according to claim 1 or 2, wherein adjusting the timing deviation of the time domain channel estimation result according to the first timing offset value comprises:

And shifting the time domain tap corresponding to the first timing offset in the time domain channel estimation result to the zeroth time domain tap, and sequentially shifting each time domain tap in the time domain channel estimation result to obtain the adjusted The time domain channel estimation result is:
Where k=0,...,N FFT -1, N FFT represents the number of FFT points, and τ 1 represents the first timing offset value,
Indicates the number of port p
The time domain channel estimation result of the column pilot.
The method of claim 7, wherein determining the second effective path threshold based on the second noise window power and the peak power comprises:

Calculating a product of the second noise window power and a third coefficient to obtain a third product, and calculating the peak power and The product of the fourth coefficient yields a fourth product;

Determining a maximum value of the third product and the fourth product, and determining that the maximum value is greater than or equal to the peak power, determining that the second effective path threshold is the peak power, and determining the maximum The value is less than the peak power, and the second effective path threshold is determined to be the maximum value.
The method according to claim 2, wherein the tap search space is searched for determining the current cell and said according to said adjusted time domain channel estimation result, said second effective path threshold, and said timing deviation The delay spread value of the neighboring cell, including:

Determining the first path position according to the adjusted time domain channel estimation result and the second effective path threshold:

i=-N leak ,...,N τ ,N τ represents the time domain position of the maximum delay time, r represents the receiving antenna number index, N FFT represents the number of FFT points, and p represents the port number.
Indicates the index number of the column where the pilot of port p is located.
Representing a second effective path threshold, N leak represents the number of paths of the retained N FFT , (τ' 1 + τ 1 ) represents the timing deviation, τ 1 represents the first timing deviation, and τ' 1 represents the Second timing deviation;

Determine the position of the trailing diameter as:

Where i=-N leak ,...,N τ ,r denotes the receiving antenna number index, N FFT denotes the number of FFT points, and p denotes the port number,
Indicates the index number of the column where the pilot of port p is located.
Representing a second effective path threshold, N leak represents the number of paths of the retained N FFT , (τ' 1 + τ 1 ) represents the timing deviation, τ 1 represents the first timing deviation, and τ' 1 represents the Second timing deviation;

Determining a result of subtracting the position of the trailing path from the position of the trailing path, and determining the result as a delay spread value of a current cell and the neighboring cell.
A timing deviation estimating device, comprising:

a first processing module, configured to determine a time domain channel estimation result by using a common reference signal CRS of a neighboring cell of the current cell, and determine a first noise window power and a peak power of the time domain channel estimation result;

a second processing module, configured to determine a first effective path threshold according to the first noise window power and the peak power, and determine, according to the time domain channel estimation result and the first effective path threshold, a current cell and the a first timing offset value of the neighboring cell;

a third processing module, configured to adjust, according to the first timing offset value, a timing offset of the time domain channel estimation result, to determine a second noise window power of the adjusted time domain channel estimation result, according to the second The noise window power and the peak power determine a second effective path threshold;

a fourth processing module, configured to perform a search on the tap search space to determine a second timing offset value of the current cell and the neighboring cell according to the adjusted time domain channel estimation result and the second effective path threshold, according to the The first timing offset value and the second timing offset value determine a timing offset between the current cell and the neighboring cell.
The apparatus of claim 10, further comprising a fifth processing module for:

And searching for the tap search space to determine a delay spread value of the current cell and the neighboring cell according to the adjusted time domain channel estimation result, the second effective path threshold, and the timing offset.
The device according to claim 10 or 11, wherein the first processing module is specifically configured to:

Obtaining a frequency domain channel estimation result according to the least squares estimation of the CRS of the neighboring cell, performing inverse discrete Fourier transform on the frequency domain channel estimation result, to obtain the time domain channel estimation result.
The device according to claim 10 or 11, wherein the first processing module is specifically configured to:

Calculating a square of a modulus of a time domain channel estimation result for each column of pilots of each port in the time domain channel estimation result, expressed as:
among them,
Indicates the number of port p
The time domain channel estimation result of the column pilot, r represents the receiving antenna number index, and N FFT represents the FFT point number;

Determining, according to a square of a modulus of a time domain channel estimation result of each column pilot of each port in the time domain channel estimation result, the first noise window power is:
Where N τ represents the time domain position of the maximum path of the delay, and N leak represents the number of paths of the reserved N FFT ;

Determining, according to a square of a modulus of a time domain channel estimation result of each column of pilots of each port in the time domain channel estimation result, the peak power is:
The device according to claim 13, wherein the second processing module is specifically configured to:

Calculating a product of the first noise window power and a first coefficient to obtain a first product, and calculating a product of the peak power and a second coefficient to obtain a second product;

Determining a maximum value of the first product and the second product, and determining that the maximum value is greater than or equal to the peak power, determining that the first effective path threshold is the peak power, and determining the maximum The value is less than the peak power, Determining that the first effective path threshold is the maximum value.
The device according to claim 14, wherein the second processing module is specifically configured to:

Determining a first timing offset value of the current cell and the neighboring cell:

among them,
P represents the total number of ports, and R represents the total number of receiving antennas, where Γ (r, p) represents the first effective path threshold.
The device according to claim 10 or 11, wherein the third processing module is specifically configured to:

And shifting the time domain tap corresponding to the first timing offset in the time domain channel estimation result to the zeroth time domain tap, and sequentially shifting each time domain tap in the time domain channel estimation result to obtain the adjusted The time domain channel estimation result is:
Where k=0,...,N FFT -1, N FFT represents the number of FFT points, and τ 1 represents the first timing offset value,
Indicates the number of port p
The time domain channel estimation result of the column pilot.
The device according to claim 16, wherein the third processing module is specifically configured to:

Calculating a product of the second noise window power and a third coefficient to obtain a third product, and calculating a product of the peak power and the fourth coefficient to obtain a fourth product;

Determining a maximum value of the third product and the fourth product, and determining that the maximum value is greater than or equal to the peak power, determining that the second effective path threshold is the peak power, and determining the maximum The value is less than the peak power, and the second effective path threshold is determined to be the maximum value.
The device of claim 11, wherein the fifth processing module is specifically configured to:

Determining the first path position according to the adjusted time domain channel estimation result and the second effective path threshold:

i=-N leak ,...,N τ ,N τ represents the time domain position of the maximum delay time, r represents the receiving antenna number index, N FFT represents the number of FFT points, and p represents the port number.
Indicates the index number of the column where the pilot of port p is located.
Representing a second effective path threshold, N leak represents the number of paths of the retained N FFT , (τ' 1 + τ 1 ) represents the timing deviation, τ 1 represents the first timing deviation, and τ' 1 represents the Second timing deviation;

Determine the position of the trailing diameter as:

Where i=-N leak ,...,N τ ,r denotes the receiving antenna number index, N FFT denotes the number of FFT points, and p denotes the port number,
Indicates the index number of the column where the pilot of port p is located.
Representing a second effective path threshold, N leak represents the number of paths of the retained N FFT , (τ' 1 + τ 1 ) represents the timing deviation, τ 1 represents the first timing deviation, and τ' 1 represents the Second timing deviation;

Determining a result of subtracting the position of the trailing path from the position of the trailing path, and determining the result as a delay spread value of a current cell and the neighboring cell.
A terminal, comprising: a processor and a memory, wherein the memory stores a preset program, the processor is configured to read a program saved in the memory, and execute the following process according to the program;

Determining a time domain channel estimation result according to a channel estimation of a common reference signal CRS of a neighboring cell of the current cell, and determining a first noise window power and a peak power of the time domain channel estimation result;

Determining a first effective path threshold according to the first noise window power and the peak power, and determining a first timing deviation between a current cell and the neighboring cell according to the time domain channel estimation result and the first effective path threshold value;

Adjusting a timing offset of the time domain channel estimation result according to the first timing offset value, determining a second noise window power of the adjusted time domain channel estimation result, according to the second noise window power and the peak value The power determines a second effective path threshold;

And performing a search on the tap search space to determine a second timing offset value of the current cell and the neighboring cell according to the adjusted time domain channel estimation result and the second effective path threshold, according to the first timing offset value and The second timing offset value determines a timing offset between the current cell and the neighboring cell.