WO2019052297A1 - Frequency offset estimation method, apparatus and device, and computer-readable storage medium - Google Patents

Abstract

Provided are a frequency offset estimation method, apparatus and device, and a computer-readable storage medium. The disclosed frequency offset estimation method comprises: receiving a time-domain signal on each path sent by a transmitting end, and obtaining, according to the time-domain signal on each of the paths, time-frequency resources on each of the paths; respectively performing channel estimation on the time-frequency resources on each of the paths, so as to obtain a frequency-domain channel estimated value on each of the paths; according to the frequency-domain channel estimated value on each of the paths, determining a time-domain channel estimated value on each of the paths; and according to the time-domain channel estimated value on each of the paths, determining a frequency offset on each of the paths.

Description

Frequency offset estimation method, device, device and computer readable storage medium

Cross-reference to related applications

The present application claims priority to Chinese Patent Application No. 201710817405.8, filed on Sep. 12, 2011, the entire content of

Technical field

The present disclosure relates to the field of communications technologies, and in particular, to a frequency offset estimation method, apparatus, device, and computer readable storage medium.

Background technique

In the high-speed rail environment, multiple antennas in the same cell are deployed along the high-speed rail through RRH (Remote Radio Unit), thereby increasing cell coverage and reducing switching frequency to improve network performance. Normally, multiple RRHs are set up in a high-speed rail environment. Here, a high-iron environment having a plurality of RRHs is referred to as a multiple RRH high-iron environment.

However, when the UE (User Equipment) is located in the middle of two RRHs in the same cell, the UE receives two (or more) signals with opposite Doppler frequency offsets, thereby forming fast fading, which seriously affects the receiving performance. .

There are two main reasons for the carrier frequency deviation: one is the deviation of the local oscillator frequency at the originating and terminating ends; the other is the deviation caused by the Doppler shift caused by the relative motion.

In the frequency offset estimation method in the related art, in the OFDM (Orthogonal Frequency Division Multiplexing) system, only a single frequency offset Δf can be estimated. In the high-speed rail environment, multiple RRHs (or multiple paths) may have different frequency offsets, and the different techniques may not be used to estimate these different frequency offsets, resulting in inaccurate frequency offset estimation results using related techniques.

Summary of the invention

In view of this, the present disclosure provides a frequency offset estimation method, apparatus, device, and computer readable storage medium for improving the accuracy of frequency offset estimation in a multi-RRH high-iron environment.

To solve the above technical problem, in a first aspect, an embodiment of the present disclosure provides a frequency offset estimation method, including:

Receiving time domain signals on the paths sent by the transmitting end, and obtaining time-frequency resources on the paths according to the time domain signals on the paths;

Performing channel estimation on the time-frequency resources on the respective paths to obtain frequency domain channel estimation values on the paths;

Determining a time domain channel estimation value on each path according to the frequency domain channel estimation value on each path;

Determining frequency offsets on the respective paths based on the time domain channel estimation values on the respective paths.

Optionally, the receiving the time domain signal on each path sent by the transmitting end, and obtaining the time-frequency resources on the paths according to the time domain signals on the paths, including:

Receiving a time domain signal on each path sent by the transmitting end;

Performing a fast Fourier transform FFT on the time domain signals on the respective paths to obtain time-frequency resources on the respective paths.

Optionally, performing channel estimation on the time-frequency resources on the paths to obtain frequency domain channel estimation values on the paths, including:

Performing a least squares LS channel estimation on the time-frequency resources on the respective paths to obtain frequency domain channel estimation values on the respective paths.

Optionally, determining, according to the frequency domain channel estimation value on each path, the time domain channel estimation value on each path, including:

An inverse discrete Fourier transform (IDFT) is performed on the sequence consisting of the frequency domain channel estimation values on the respective paths to determine time domain channel estimation values on the respective paths.

Optionally, determining, according to the time domain channel estimation values on the paths, the frequency offsets on the paths, including:

Calculating, by using the first time domain channel estimation value and the second time domain channel estimation value in the time domain channel estimation values on the respective paths, a conjugate of the first time domain channel estimation value to obtain a value;

Multiplying the value and the second time domain channel estimate to determine a frequency offset on the first path;

The first time domain channel estimation value and the second time domain channel estimation value are time domain channel estimation values corresponding to different paths.

Optionally, the method further includes:

Automatic frequency tracking is performed on the frequency offset.

Optionally, the performing automatic frequency tracking on the frequency offset includes:

Determining a weighted average coefficient corresponding to each path;

Calculating a weighted average value of the frequency offsets on the respective paths according to the weighted average coefficients corresponding to the respective paths and the frequency offsets on the respective paths;

Automatic frequency tracking is performed on the frequency offset weighted average.

Optionally, calculating a frequency offset weighted average value on each path according to the weighted average coefficient corresponding to each path and the frequency offset on each path, including:

The weighted average of the frequency offsets on each of the paths is calculated using the following formula:

Where Δf represents the frequency offset weighted average, P(Δf _p ) represents the weighted average coefficient corresponding to each path, and Δf _p represents the frequency offset on each path, p=1, 2,...n,

Indicates the first symbol, the time domain channel estimate on the p-th path, and n represents the total number of paths.

Optionally, the performing automatic frequency tracking on the frequency offset includes:

Determining the target frequency offset from the frequency offsets on the respective paths according to a preset rule;

Automatic frequency tracking is performed on the target frequency offset.

In a second aspect, an embodiment of the present disclosure provides a frequency offset estimation method, including:

Obtain time-frequency resources on each path;

Performing an inverse fast Fourier transform (IFFT) on the time-frequency resources on the respective paths to obtain time-domain signals on the respective paths;

The time domain signals on the respective paths are transmitted to the receiving end.

In a third aspect, an embodiment of the present disclosure provides a frequency offset estimation apparatus, including: a transceiver, a memory, a processor, and a computer program stored on the memory and operable on the processor;

The transceiver is configured to receive a time domain signal on each path sent by the transmitting end;

The processor is configured to read a program in the memory and perform the following process:

Obtaining time-frequency resources on the respective paths according to the time domain signals on the respective paths; performing channel estimation on the time-frequency resources on the respective paths to obtain frequency-domain channel estimation values on the respective paths; The frequency domain channel estimation values on the respective paths determine the time domain channel estimation values on the respective paths; and determine the frequency offsets on the respective paths according to the time domain channel estimation values on the respective paths.

Optionally, the processor is further configured to read a program in the memory, and perform the following process: performing fast Fourier transform FFT on the time domain signals on the respective paths to obtain time-frequency on the respective paths. Resources.

Optionally, the processor is further configured to read a program in the memory, and perform the following process: performing least-squares LS channel estimation on the time-frequency resources on the paths respectively to obtain frequency-domain channel estimation on each path. value.

Optionally, the processor is further configured to read a program in the memory, and perform the following process: performing an inverse discrete Fourier transform (IDFT) on the sequence consisting of the frequency domain channel estimation values on the respective paths to determine the Time domain channel estimates on each path.

Optionally, the processor is further configured to read a program in the memory, and perform the following process:

Calculating, by using the first time domain channel estimation value and the second time domain channel estimation value in the time domain channel estimation values on the respective paths, a conjugate of the first time domain channel estimation value to obtain a value;

Multiplying the value and the second time domain channel estimate to determine a frequency offset on the first path;

The first time domain channel estimation value and the second time domain channel estimation value are time domain channel estimation values corresponding to different paths.

Optionally, the processor is further configured to read a program in the memory, and perform the following process:

Automatic frequency tracking is performed on the frequency offset.

Optionally, the processor is further configured to read a program in the memory, and perform the following process:

Determining a weighted average coefficient corresponding to each path;

Calculating a weighted average value of the frequency offsets on the respective paths according to the weighted average coefficients corresponding to the respective paths and the frequency offsets on the respective paths;

Automatic frequency tracking is performed on the frequency offset weighted average.

Optionally, the processor is further configured to read a program in the memory, and perform the following process:

The weighted average of the frequency offsets on each of the paths is calculated using the following formula:

Where Δf represents the frequency offset weighted average, P(Δf _p ) represents the weighted average coefficient corresponding to each path, and Δf _p represents the frequency offset on each path, p=1, 2,...n,

Indicates the first symbol, the time domain channel estimate on the p-th path, and n represents the total number of paths.

Optionally, the processor is further configured to read a program in the memory, and perform the following process:

Determining the target frequency offset from the frequency offsets on the respective paths according to a preset rule;

Automatic frequency tracking is performed on the target frequency offset.

In a fourth aspect, an embodiment of the present disclosure provides a frequency offset estimation apparatus, including: a transceiver, a memory, a processor, and a computer program stored on the memory and operable on the processor;

The processor is configured to read a program in the memory and perform the following process:

Obtaining time-frequency resources on each path; performing inverse fast Fourier transform IFFT on the time-frequency resources on the respective paths to obtain time-domain signals on each path;

The transceiver is configured to send a time domain signal on each path to a receiving end.

In a fifth aspect, an embodiment of the present disclosure provides a frequency offset estimation apparatus, including:

a first acquiring module, configured to receive a time domain signal on each path sent by the transmitting end, and obtain time-frequency resources on the paths according to the time domain signals on the paths;

a second acquiring module, configured to separately perform channel estimation on the time-frequency resources on the paths, and obtain frequency domain channel estimation values on the paths;

a first determining module, configured to determine, according to the frequency domain channel estimation values on the paths, time domain channel estimation values on the paths;

And a second determining module, configured to determine a frequency offset on the paths according to the time domain channel estimation values on the paths.

Optionally, the second determining module includes:

a calculation submodule, configured to calculate a conjugate of the first time domain channel estimation value for the first time domain channel estimation value and the second time domain channel estimation value in the time domain channel estimation values on the respective paths, Obtain a value;

Determining a submodule, configured to multiply the value and the second time domain channel estimate to determine a frequency offset on the first path;

The first time domain channel estimation value and the second time domain channel estimation value are time domain channel estimation values corresponding to different paths.

Optionally, the device further includes:

A tracking module is configured to perform automatic frequency tracking on the frequency offset.

Optionally, the tracking module includes:

Determining a sub-module for determining a weighted average coefficient corresponding to each path;

a calculation submodule, configured to calculate a weighted average value of the frequency offsets on the respective paths according to the weighted average coefficients corresponding to the paths and the frequency offsets on the respective paths;

The tracking submodule is configured to perform automatic frequency tracking on the frequency offset averaged value.

In a sixth aspect, an embodiment of the present disclosure provides a frequency offset estimation apparatus, including:

a first obtaining module, configured to obtain time-frequency resources on each path;

a second obtaining module, configured to perform an inverse fast Fourier transform IFFT on the time-frequency resources on the respective paths to obtain a time domain signal on each path;

And a sending module, configured to send, to the receiving end, a time domain signal on each path.

A seventh aspect, an embodiment of the present disclosure provides a computer readable storage medium for storing a computer program, the computer program being executed by a processor to implement the steps in the method as described in the first aspect; or the computer program The steps in the method as described in the second aspect are implemented when executed by a processor.

The beneficial effects of the above technical solutions of the present disclosure are as follows:

In the embodiment of the present disclosure, the time-frequency resources on the paths are obtained according to the time-domain signals on the multi-path, and the time-frequency resources on the paths are respectively channel-estimated to obtain the frequency-domain channel estimation on the paths. value. And determining, according to the frequency domain channel estimation values on the paths, time domain channel estimation values on the paths, and determining frequency of the paths according to the time domain channel estimation values on the paths. Partial. It can be seen that in the embodiment of the present disclosure, in the high-iron multi-RRH environment, the frequency offset on each path can be estimated, thereby improving the accuracy of frequency offset estimation in a multi-RRH high-iron environment.

DRAWINGS

1 is a flowchart of a frequency offset estimation method according to an embodiment of the present disclosure;

2 is a flowchart of a frequency offset estimation method according to an embodiment of the present disclosure;

3 is a schematic block diagram of a processing procedure of an LTE transmitter/receiver in an embodiment of the present disclosure;

4 is a schematic diagram of a CRS time-frequency position;

FIG. 5 is a schematic diagram of a processing procedure after the receiving end obtains time domain resources on each path;

6 is a schematic diagram of a frequency offset estimation apparatus according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of a first acquiring module in a frequency offset estimating apparatus according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a second determining module in a frequency offset estimating apparatus according to an embodiment of the present disclosure;

FIG. 9 is still another schematic diagram of a frequency offset estimation apparatus according to an embodiment of the present disclosure;

10 is a schematic diagram of a tracking module in a frequency offset estimation apparatus according to an embodiment of the present disclosure;

11 is a schematic diagram of a frequency offset estimation apparatus according to an embodiment of the present disclosure;

12 is a schematic diagram of a frequency offset estimation apparatus according to an embodiment of the present disclosure;

FIG. 13 is a schematic diagram of a frequency offset estimation apparatus according to an embodiment of the present disclosure.

Detailed ways

Specific embodiments of the present disclosure will be further described in detail below with reference to the drawings and embodiments. The following examples are intended to illustrate the disclosure, but are not intended to limit the scope of the disclosure.

As shown in FIG. 1, the frequency offset estimation method of the embodiment of the present disclosure is applied to a receiving end, and includes steps 101 to 104.

Step 101: Receive a time domain signal on each path sent by the transmitting end, and obtain time-frequency resources on the paths according to the time domain signals on the paths.

In the embodiment of the present disclosure, the transmission path of each RRH may be referred to as a path or a path. In multiple RRH high-iron environments, there are multiple diameters. Here, for each path, a time domain signal on each path sent by the transmitting end may be received, and time-frequency resources on the respective paths are obtained according to the time domain signals on the respective paths.

Specifically, receiving a time domain signal on each path sent by the transmitting end, and performing fast Fourier transform (FFT) on the time domain signals on the respective paths to obtain time on the respective paths. Frequency resources.

Step 102: Perform channel estimation on the time-frequency resources on the paths to obtain frequency domain channel estimation values on the paths.

In this step, least-square estimation (LS) channel estimation is performed on the time-frequency resources on the respective paths to obtain frequency-domain channel estimation values on the respective paths.

Step 103: Determine a time domain channel estimation value on each path according to the frequency domain channel estimation value on each path.

Here, an inverse Fourier Transform (IDFT) is performed on a sequence consisting of frequency domain channel estimation values on the respective paths to determine time domain channel estimation values on the respective paths.

Step 104: Determine a frequency offset on each path according to the time domain channel estimation value on each path.

In this step, calculating a conjugate of the first time domain channel estimation value for the first time domain channel estimation value and the second time domain channel estimation value in the time domain channel estimation values on the respective paths, obtaining A value that multiplies the value by the second time domain channel estimate to determine a frequency offset on the first path.

The first time domain channel estimation value and the second time domain channel estimation value are time domain channel estimation values corresponding to different paths.

In the embodiment of the present disclosure, the time-frequency resources on the paths are obtained according to the time-domain signals on the multi-path, and the time-frequency resources on the paths are respectively channel-estimated to obtain the frequency-domain channel estimation on the paths. value. And determining, according to the frequency domain channel estimation values on the paths, time domain channel estimation values on the paths, and determining frequency of the paths according to the time domain channel estimation values on the paths. Partial. It can be seen that in the embodiment of the present disclosure, in the high-iron multi-RRH environment, the frequency offset on each path can be estimated, thereby improving the accuracy of frequency offset estimation in a multi-RRH high-iron environment.

As shown in FIG. 2, the frequency offset estimation method of the embodiment of the present disclosure includes steps 201 to 203.

Step 201: Obtain time-frequency resources on each path.

Step 202: Perform inverse fast Fourier transform (IFFT) on the time-frequency resources on the respective paths to obtain time domain signals on the respective paths.

Step 203: Send a time domain signal on each path to the receiving end.

In the embodiment of the present disclosure, the time-frequency resources on the paths are obtained according to the time-domain signals on the multi-path, and the time-frequency resources on the paths are respectively channel-estimated to obtain the frequency-domain channel estimation on the paths. value. And determining, according to the frequency domain channel estimation values on the paths, time domain channel estimation values on the paths, and determining frequency of the paths according to the time domain channel estimation values on the paths. Partial. It can be seen that in the embodiment of the present disclosure, in the high-iron multi-RRH environment, the frequency offset on each path can be estimated, thereby improving the accuracy of frequency offset estimation in a multi-RRH high-iron environment.

The specific implementation process of the disclosed frequency offset estimation method will be described in detail in conjunction with the following embodiments.

Take LTE (long term evolution) as an example. As shown in Figure 3, it is a schematic block diagram of the LTE transmitter/receiver processing.

Let a _k,l denote the time-frequency resource on the kth subcarrier and the lth symbol at the transmitting end, and s _l (t) denote the time domain signal on the tth sample of the lth symbol after the IFFT of the transmitting end .

At the transmitting end, time-frequency resources on each path are obtained, and fast time Fourier transforms are performed on the time-frequency resources on the respective paths to obtain time-domain signals on the respective paths, and the paths are sent to the receiving end. Time domain signal.

It is assumed that under the "multi-RRH high-iron environment", there are n RRHs, and the Doppler shifts are Δf ₁ , Δf ₂ , ..., Δf _n , respectively; the multipath delays are Δt ₁ , Δt ₂ , ..., Δt _n ; The relative powers are p ₁ , p ₂ ,..., p _{n , respectively} .

For the receiving end, the time domain signals on the paths sent by the transmitting end are received, and the time-frequency resources on the paths are obtained according to the time domain signals on the respective paths.

y _l (t) represents the time domain signal on the tth sample of the lth symbol at the receiving end,

p = 1, 2, ..., n, where n(t) represents the noise at time t.

r _k,l =FFT[y _l (t)], indicating the time-frequency resource on the kth subcarrier and the lth symbol after the FFT is changed at the receiving end.

In LTE, cell-specific pilot (or common pilot) (Cell-specific RS, CRS) is discretely distributed in the time domain/frequency domain, and R ₀ represents the CRS time-frequency location.

FIG. 5 is a schematic diagram of a processing procedure after the receiving end obtains time domain resources on each path. Referring to FIG. 5, at the receiving end, LS channel estimation is performed on time-frequency resources on the respective paths, and frequency domain channel estimation values on the respective paths are obtained.

According to r _k,l and the known pilot symbol a _k,l , assuming that the noise influence is ignored, the frequency domain channel estimation value of the CRS position can be obtained by LS estimation:

According to the frequency domain sampling theorem, if the sequence length is M, the original time domain signal x(n) can be recovered without distortion by the frequency domain sampling X(k) only when the frequency domain sampling point number N>=M; otherwise, Time domain aliasing. In general, the number of resolvable multipaths is limited, and the maximum multipath delay <the number of CRS samples in the frequency domain, so the frequency domain sampling theorem is satisfied.

Frequency domain channel estimate for each subcarrier for each symbol

The sequence H ₁ of the sequence is changed, and the time domain channel estimation value of each subcarrier can be recovered, and the time domain channel estimation value of the first symbol and the pth path is expressed as

Taking the 20M bandwidth of the LTE system as an example, the FFT length is 2048, that is, there are 2048 subcarriers in the frequency domain (including 1200 effective subcarriers, and the rest are virtual subcarriers). The CRS is equally spaced apart by 6 subcarriers in the frequency domain, for a total of 200 CRS subcarriers. Since 2048/6 is not an integer, frequency domain sampling of equal intervals of 6 cannot be performed on 2048 subcarriers, that is, sampling of equal interval 6 is actually non-uniform sampling.

Suppose that a rectangular window is added to 2048 subcarriers in the frequency domain, for example: 2048->1944, then 1944/6=324 is an integer, that is, the IDFT length is 324; or 2048->1536, then 1536/6=256, that is, the IDFT length is 256. However, the frequency domain plus rectangular window is equivalent to the time domain convolution sinc function, which will cause aliasing of the time domain channel estimation, compared with "2048->1944" and "2048->1536", "2048->1944 The sinc function has smaller side lobes. Assuming the IDFT length is selected from 324 or 256, it is recommended to select the IDFT length to take 324.

The time domain channel estimation of each symbol has the following relationship:

Indicates the l+Δt symbols and the time domain channel estimation values on the pth path.

So, similarly, it can be done by different symbol positions

Do conjugate multiplication and get

And because Δt is known, it is possible to phase C _p multiplication results obtained in accordance with conjugated p-th frequency offset [Delta] f _p in diameter, so as to achieve a different frequency offset value estimated from the plurality of the RRH (or multiple diameter) the goal of.

Based on the above calculation of the frequency offset on each path, the embodiment of the present disclosure can also use the frequency offset to perform automatic frequency tracking (also called Automatic Frequency Control (AFC)).

For automatic frequency tracking, only a single frequency offset can be tracked/corrected. Therefore, when there are multiple frequency offsets under the “multi-RRH high-speed rail environment”, it is necessary to consider how to perform automatic frequency tracking. The frequency offset will cause Inter Carrier Interference (ICI) in the OFDM system. In the "multi-RRH high-speed rail environment", ICI will inevitably exist because the frequency offset of all the paths cannot be corrected.

However, the effect of ICI can be minimized by weighted averaging of the path offsets, and at the same time, the AFC tracking frequency offset Δf can be prevented from being rapidly hopped.

That is, determining a weighted average coefficient corresponding to each path, calculating a frequency offset weighted average value on each path according to the weighted average coefficient corresponding to each path and the frequency offset on each path, and weighting the frequency offset The average is used for automatic frequency tracking.

The weighted average of the frequency offsets on each of the paths is calculated using the following formula:

among them,

Where Δf represents the frequency offset weighted average, P(Δf _p ) represents the weighted average coefficient corresponding to each path, and Δf _p represents the frequency offset on each path, p=1, 2,...n,

Indicates the first symbol, the time domain channel estimate on the p-th path, and n represents the total number of paths.

Alternatively, in a specific application, the target frequency offset may be determined from the frequency offsets on the paths according to a preset rule, and the target frequency offset is automatically frequency-tracked.

The preset rule may be any selection, or may be a fixed selection of a frequency offset on a certain path.

It should be noted that the method of the foregoing embodiment is applicable not only to the LTE system but also to all OFDM systems.

As can be seen from the above, the embodiments of the present disclosure can accurately estimate the path offsets under the “multi-RRH high-iron environment” and can optimize the automatic frequency tracking performance by using the weighted average results of the path offsets.

As shown in FIG. 6, the frequency offset estimation apparatus of the embodiment of the present disclosure includes:

The first obtaining module 601 is configured to receive time domain signals on the paths sent by the transmitting end, and obtain time-frequency resources on the paths according to the time domain signals on the paths; and the second obtaining module 602 uses Performing channel estimation on the time-frequency resources on the respective paths to obtain frequency-domain channel estimation values on the respective paths; the first determining module 603 is configured to determine, according to the frequency domain channel estimation values on the paths, The time domain channel estimation value on each path is determined; and the second determining module 604 is configured to determine a frequency offset on each path according to the time domain channel estimation value on each path.

Optionally, as shown in FIG. 7, the first acquiring module 601 includes:

The receiving sub-module 6011 is configured to receive a time domain signal on each path sent by the transmitting end;

The transform sub-module 6012 is configured to perform fast Fourier transform on the time domain signals on the respective paths to obtain time-frequency resources on the paths.

Optionally, the second obtaining module 602 is specifically configured to perform LS channel estimation on the time-frequency resources on the paths respectively, and obtain frequency domain channel estimation values on the paths.

Optionally, the first determining module 603 is specifically configured to perform inverse discrete Fourier transform on a sequence consisting of frequency domain channel estimation values on the paths to determine time domain channel estimation on the paths. value.

Optionally, as shown in FIG. 8, the second determining module 604 includes: a calculating submodule 6041, configured to use a first time domain channel estimation value and a second one of the time domain channel estimation values on the respective paths. a time domain channel estimation value, calculating a conjugate of the first time domain channel estimation value, obtaining a value; a determining submodule 6042, configured to multiply the value and the second time domain channel estimation value to determine a frequency offset on a path; wherein the first time domain channel estimation value and the second time domain channel estimation value are time domain channel estimation values corresponding to different paths.

As shown in FIG. 9, the apparatus further includes: a tracking module 605, configured to perform automatic frequency tracking on the frequency offset.

As shown in FIG. 10, the tracking module 605 includes:

a determining sub-module 6051, configured to determine a weighted average coefficient corresponding to each path; a calculation sub-module 6052, configured to calculate, according to the weighted average coefficient corresponding to each path and the frequency offset on each path, The frequency offset weighted average; the tracking sub-module 6053 is configured to perform automatic frequency tracking on the frequency offset weighted average.

Specifically, the weighted average of the frequency offsets on the respective paths is calculated by using the following formula:

Where Δf represents the frequency offset weighted average, P(Δf _p ) represents the weighted average coefficient corresponding to each path, and Δf _p represents the frequency offset on each path, p=1, 2,...n,

Indicates the first symbol, the time domain channel estimate on the p-th path, and n represents the total number of paths.

Alternatively, the tracking module 605 is specifically configured to determine a target frequency offset from the frequency offsets on the paths according to a preset rule, and perform automatic frequency tracking on the target frequency offset.

The working principle of the device of the present disclosure can be referred to the description of the foregoing method embodiments.

In the embodiment of the present disclosure, the time-frequency resources on the paths are obtained according to the time-domain signals on the multi-path, and the time-frequency resources on the paths are respectively channel-estimated to obtain the frequency-domain channel estimation on the paths. value. And determining, according to the frequency domain channel estimation values on the paths, time domain channel estimation values on the paths, and determining frequency of the paths according to the time domain channel estimation values on the paths. Partial. It can be seen that in the embodiment of the present disclosure, in the high-iron multi-RRH environment, the frequency offset on each path can be estimated, thereby improving the accuracy of frequency offset estimation in a multi-RRH high-iron environment.

As shown in FIG. 11, the frequency offset estimation apparatus of the embodiment of the present disclosure includes:

The first obtaining module 1101 is configured to obtain time-frequency resources on each path, and the second obtaining module 1102 is configured to perform inverse fast Fourier transform (IFFT) on the time-frequency resources on the paths to obtain the paths on the paths. The time domain signal is sent by the sending module 1103, and is configured to send the time domain signal on each path to the receiving end.

The working principle of the device of the present disclosure can be referred to the description of the foregoing method embodiments.

In the embodiment of the present disclosure, the time-frequency resources on the paths are obtained according to the time-domain signals on the multi-path, and the time-frequency resources on the paths are respectively channel-estimated to obtain the frequency-domain channel estimation on the paths. value. And determining, according to the frequency domain channel estimation values on the paths, time domain channel estimation values on the paths, and determining frequency of the paths according to the time domain channel estimation values on the paths. Partial. It can be seen that in the embodiment of the present disclosure, in the high-iron multi-RRH environment, the frequency offset on each path can be estimated, thereby improving the accuracy of frequency offset estimation in a multi-RRH high-iron environment.

As shown in FIG. 12, the frequency offset estimation apparatus of the embodiment of the present disclosure includes:

The processor 1200 is configured to read a program in the memory 1220, and perform the following process: receiving, by the transceiver 1210, a time domain signal on each path sent by the transmitting end, and obtaining the each according to the time domain signal on each path a time-frequency resource on the path; performing channel estimation on the time-frequency resources on the paths respectively, obtaining frequency domain channel estimation values on the paths; determining the location according to the frequency domain channel estimation values on the paths Determining a time domain channel estimation value on each path; determining frequency offsets on the respective paths according to the time domain channel estimation values on the respective paths;

The transceiver 1210 is configured to receive and transmit data under the control of the processor 1200.

In FIG. 12, the bus architecture can include any number of interconnected buses and bridges, specifically linked by one or more processors represented by processor 1200 and various circuits of memory represented by memory 1220. 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 transceiver 1210 can be a plurality of components, including a transmitter and a transceiver, providing means for communicating with various other devices on a transmission medium. The processor 1200 is responsible for managing the bus architecture and general processing, and the memory 1220 can store data used by the processor 1200 in performing operations.

The processor 1200 is responsible for managing the bus architecture and general processing, and the memory 1220 can store data used by the processor 1200 in performing operations.

The processor 1200 is further configured to read the computer program, and perform the following steps:

Performing a fast Fourier transform FFT on the time domain signals on the respective paths to obtain time-frequency resources on the respective paths.

The processor 1200 is further configured to read the computer program, and perform the following steps:

The least squares LS channel estimation is performed on the time-frequency resources on the respective paths to obtain frequency domain channel estimation values on the respective paths.

The processor 1200 is further configured to read the computer program, and perform the following steps:

An inverse discrete Fourier transform (IDFT) is performed on the sequence consisting of the frequency domain channel estimation values on the respective paths to determine time domain channel estimation values on the respective paths.

The processor 1200 is further configured to read the computer program, and perform the following steps:

Calculating, by using the first time domain channel estimation value and the second time domain channel estimation value in the time domain channel estimation values on the respective paths, a conjugate of the first time domain channel estimation value to obtain a value;

Multiplying the value and the second time domain channel estimate to determine a frequency offset on the first path;

The first time domain channel estimation value and the second time domain channel estimation value are time domain channel estimation values corresponding to different paths.

The processor 1200 is further configured to read the computer program, and perform the following steps: performing automatic frequency tracking on the frequency offset.

The processor 1200 is further configured to read the computer program, and perform the following steps:

Determining a weighted average coefficient corresponding to each path;

Calculating a weighted average value of the frequency offsets on the respective paths according to the weighted average coefficients corresponding to the respective paths and the frequency offsets on the respective paths;

Automatic frequency tracking is performed on the frequency offset weighted average.

The processor 1200 is further configured to read the computer program, and perform the following steps:

The weighted average of the frequency offsets on each of the paths is calculated using the following formula:

Where Δf represents the frequency offset weighted average, P(Δf _p ) represents the weighted average coefficient corresponding to each path, and Δf _p represents the frequency offset on each path, p=1, 2,...n,

Indicates the first symbol, the time domain channel estimate on the p-th path, and n represents the total number of paths.

The processor 1200 is further configured to read the computer program, and perform the following steps:

Determining the target frequency offset from the frequency offsets on the respective paths according to a preset rule;

Automatic frequency tracking is performed on the target frequency offset.

As shown in FIG. 13, the frequency offset estimation apparatus of the embodiment of the present disclosure includes:

The processor 1300 is configured to read the program in the memory 1320, and perform the following process: obtaining time-frequency resources on each path, performing inverse fast Fourier transform IFFT on the time-frequency resources on the paths, respectively, to obtain paths The time domain signal on the upper end, and the time domain signal on each path is sent to the receiving end by the transceiver 1310;

The transceiver 1310 is configured to receive and transmit data under the control of the processor 1300.

In FIG. 13, the bus architecture may include any number of interconnected buses and bridges, specifically linked by one or more processors represented by processor 1300 and various circuits of memory represented by memory 1320. 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. Transceiver 1310 can be a plurality of components, including a transmitter and a transceiver, providing means for communicating with various other devices on a transmission medium. The processor 1300 is responsible for managing the bus architecture and general processing, and the memory 1320 can store data used by the processor 1300 in performing operations.

The processor 1300 is responsible for managing the bus architecture and general processing, and the memory 1320 can store data used by the processor 1300 in performing operations.

Furthermore, a computer readable storage medium of an embodiment of the present disclosure is configured to store a computer program executable by a processor to implement the following steps:

Obtain time-frequency resources on each path;

Performing an inverse fast Fourier transform (IFFT) on the time-frequency resources on the respective paths to obtain time-domain signals on the respective paths;

The time domain signals on the respective paths are transmitted to the receiving end.

Furthermore, a computer readable storage medium of an embodiment of the present disclosure is configured to store a computer program executable by a processor to implement the following steps:

Receiving time domain signals on the paths sent by the transmitting end, and obtaining time-frequency resources on the paths according to the time domain signals on the paths;

Performing channel estimation on the time-frequency resources on the respective paths to obtain frequency domain channel estimation values on the paths;

Determining a time domain channel estimation value on each path according to the frequency domain channel estimation value on each path;

Determining frequency offsets on the respective paths based on the time domain channel estimation values on the respective paths.

Optionally, the receiving the time domain signal on each path sent by the transmitting end, and obtaining the time-frequency resources on the paths according to the time domain signals on the paths, including:

Receiving a time domain signal on each path sent by the transmitting end;

Performing a fast Fourier transform FFT on the time domain signals on the respective paths to obtain time-frequency resources on the respective paths.

Optionally, performing channel estimation on the time-frequency resources on the paths to obtain frequency domain channel estimation values on the paths, including:

Performing a least squares LS channel estimation on the time-frequency resources on the respective paths to obtain frequency domain channel estimation values on the respective paths.

Optionally, determining, according to the frequency domain channel estimation value on each path, the time domain channel estimation value on each path, including:

An inverse discrete Fourier transform (IDFT) is performed on the sequence consisting of the frequency domain channel estimation values on the respective paths to determine time domain channel estimation values on the respective paths.

Optionally, determining, according to the time domain channel estimation values on the paths, the frequency offsets on the paths, including:

Calculating, by using the first time domain channel estimation value and the second time domain channel estimation value in the time domain channel estimation values on the respective paths, a conjugate of the first time domain channel estimation value to obtain a value;

Multiplying the value and the second time domain channel estimate to determine a frequency offset on the first path;

The first time domain channel estimation value and the second time domain channel estimation value are time domain channel estimation values corresponding to different paths.

Optionally, the method further includes:

Automatic frequency tracking is performed on the frequency offset.

Optionally, the performing automatic frequency tracking on the frequency offset includes:

Determining a weighted average coefficient corresponding to each path;

Calculating a weighted average value of the frequency offsets on the respective paths according to the weighted average coefficients corresponding to the respective paths and the frequency offsets on the respective paths;

Automatic frequency tracking is performed on the frequency offset weighted average.

Optionally, calculating a frequency offset weighted average value on each path according to the weighted average coefficient corresponding to each path and the frequency offset on each path, including:

The weighted average of the frequency offsets on each of the paths is calculated using the following formula:

Where Δf represents the frequency offset weighted average, P(Δf _p ) represents the weighted average coefficient corresponding to each path, and Δf _p represents the frequency offset on each path, p=1, 2,...n,

Indicates the first symbol, the time domain channel estimate on the p-th path, and n represents the total number of paths.

Optionally, the performing automatic frequency tracking on the frequency offset includes:

Determining the target frequency offset from the frequency offsets on the respective paths according to a preset rule;

Automatic frequency tracking is performed on the target frequency offset.

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

In addition, each functional unit in various embodiments of the present disclosure may be integrated into one processing unit, or each unit may be physically included separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of hardware plus software functional units.

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

The above is an alternative embodiment of the present disclosure, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present disclosure. It should also be considered as the scope of protection of the present disclosure.

Claims (26)

1. A frequency offset estimation method includes:

   Receiving time domain signals on the paths sent by the transmitting end, and obtaining time-frequency resources on the paths according to the time domain signals on the paths;

   Performing channel estimation on the time-frequency resources on the respective paths to obtain frequency domain channel estimation values on the paths;

   Determining a time domain channel estimation value on each path according to the frequency domain channel estimation value on each path;

   Determining frequency offsets on the respective paths based on the time domain channel estimation values on the respective paths.
2. The method according to claim 1, wherein the receiving the time domain signal on each path sent by the transmitting end, and obtaining the time-frequency resources on the respective paths according to the time domain signals on the respective paths, including:

   Receiving a time domain signal on each path sent by the transmitting end;

   Performing a fast Fourier transform FFT on the time domain signals on the respective paths to obtain time-frequency resources on the respective paths.
3. The method according to claim 1, wherein the channel estimation is performed on the time-frequency resources on the respective paths, and the frequency domain channel estimation values on the paths are obtained, including:

   Performing a least squares LS channel estimation on the time-frequency resources on the respective paths to obtain frequency domain channel estimation values on the respective paths.
4. The method according to claim 1, wherein the determining the time domain channel estimation values on the paths according to the frequency domain channel estimation values on the respective paths comprises:

   An inverse discrete Fourier transform (IDFT) is performed on the sequence consisting of the frequency domain channel estimation values on the respective paths to determine time domain channel estimation values on the respective paths.
5. The method according to claim 1, wherein the determining the frequency offset on the paths according to the time domain channel estimation values on the respective paths comprises:

   Calculating, by using the first time domain channel estimation value and the second time domain channel estimation value in the time domain channel estimation values on the respective paths, a conjugate of the first time domain channel estimation value to obtain a value;

   Multiplying the value and the second time domain channel estimate to determine a frequency offset on the first path;

   The first time domain channel estimation value and the second time domain channel estimation value are time domain channel estimation values corresponding to different paths.
6. The method of claim 1 further comprising:

   Automatic frequency tracking is performed on the frequency offset.
7. The method of claim 6 wherein said performing automatic frequency tracking on said frequency offset comprises:

   Determining a weighted average coefficient corresponding to each path;

   Calculating a weighted average value of the frequency offsets on the respective paths according to the weighted average coefficients corresponding to the respective paths and the frequency offsets on the respective paths;

   Automatic frequency tracking is performed on the frequency offset weighted average.
8. The method according to claim 7, wherein the weighted average weighted average value on the respective paths is calculated according to the weighted average coefficient corresponding to the respective paths and the frequency offset on the respective paths, including:

   The weighted average of the frequency offsets on each of the paths is calculated using the following formula:

   

   Where Δf represents the frequency offset weighted average, P(Δf _p ) represents the weighted average coefficient corresponding to each path, and Δf _p represents the frequency offset on each path, p=1, 2,...n,

   

   Indicates the first symbol, the time domain channel estimate on the p-th path, and n represents the total number of paths.
9. The method of claim 6 wherein said performing automatic frequency tracking on said frequency offset comprises:

   Determining the target frequency offset from the frequency offsets on the respective paths according to a preset rule;

   Automatic frequency tracking is performed on the target frequency offset.
10. A frequency offset estimation method includes:

    Obtain time-frequency resources on each path;

    Performing an inverse fast Fourier transform (IFFT) on the time-frequency resources on the respective paths to obtain time-domain signals on the respective paths;

    The time domain signals on the respective paths are transmitted to the receiving end.
11. A frequency offset estimating apparatus includes: a transceiver, a memory, a processor, and a computer program stored on the memory and operable on the processor; wherein

    The transceiver is configured to receive a time domain signal on each path sent by the transmitting end;

    The processor is configured to read a program in the memory and perform the following process:

    Obtaining time-frequency resources on the respective paths according to the time domain signals on the respective paths; performing channel estimation on the time-frequency resources on the respective paths to obtain frequency-domain channel estimation values on the respective paths; The frequency domain channel estimation values on the respective paths determine the time domain channel estimation values on the respective paths; and determine the frequency offsets on the respective paths according to the time domain channel estimation values on the respective paths.
12. The apparatus according to claim 11, wherein said processor is further configured to read a program in the memory, and perform the following process: performing fast Fourier transform FFT on the time domain signals on the respective paths, respectively Time-frequency resources on each path.
13. The device according to claim 11, wherein the processor is further configured to read a program in the memory, and perform the following process: performing least square LS channel estimation on the time-frequency resources on the respective paths to obtain respective Frequency domain channel estimate on the path.
14. The apparatus of claim 11 wherein said processor is further operative to read a program in the memory, the process of performing discrete Fourier on a sequence consisting of frequency domain channel estimates on said paths The inverse transform IDFT determines the time domain channel estimate on each of the paths.
15. The apparatus according to claim 11, wherein said processor is further configured to read a program in the memory and perform the following process:

    Calculating, by using the first time domain channel estimation value and the second time domain channel estimation value in the time domain channel estimation values on the respective paths, a conjugate of the first time domain channel estimation value to obtain a value;

    Multiplying the value and the second time domain channel estimate to determine a frequency offset on the first path;

    The first time domain channel estimation value and the second time domain channel estimation value are time domain channel estimation values corresponding to different paths.
16. The apparatus according to claim 11, wherein said processor is further configured to read a program in the memory and perform the following process:

    Automatic frequency tracking is performed on the frequency offset.
17. The apparatus according to claim 16, wherein said processor is further configured to read a program in the memory and perform the following process:

    Determining a weighted average coefficient corresponding to each path;

    Calculating a weighted average value of the frequency offsets on the respective paths according to the weighted average coefficients corresponding to the respective paths and the frequency offsets on the respective paths;

    Automatic frequency tracking is performed on the frequency offset weighted average.
18. The apparatus of claim 17, wherein the processor is further configured to read a program in the memory and perform the following process:

    The weighted average of the frequency offsets on each of the paths is calculated using the following formula:

    

    Where Δf represents the frequency offset weighted average, P(Δf _p ) represents the weighted average coefficient corresponding to each path, and Δf _p represents the frequency offset on each path, p=1, 2,...n,

    

    Indicates the first symbol, the time domain channel estimate on the p-th path, and n represents the total number of paths.
19. The apparatus according to claim 11, wherein said processor is further configured to read a program in the memory and perform the following process:

    Determining the target frequency offset from the frequency offsets on the respective paths according to a preset rule;

    Automatic frequency tracking is performed on the target frequency offset.
20. A frequency offset estimating apparatus includes: a transceiver, a memory, a processor, and a computer program stored on the memory and operable on the processor; wherein

    The processor is configured to read a program in the memory and perform the following process:

    Obtaining time-frequency resources on each path; performing inverse fast Fourier transform IFFT on the time-frequency resources on the respective paths to obtain time-domain signals on each path;

    The transceiver is configured to send a time domain signal on each path to a receiving end.
21. A frequency offset estimating apparatus includes:

    a first acquiring module, configured to receive a time domain signal on each path sent by the transmitting end, and obtain time-frequency resources on the paths according to the time domain signals on the paths;

    a second acquiring module, configured to separately perform channel estimation on the time-frequency resources on the paths, and obtain frequency domain channel estimation values on the paths;

    a first determining module, configured to determine, according to the frequency domain channel estimation values on the paths, time domain channel estimation values on the paths;

    And a second determining module, configured to determine a frequency offset on the paths according to the time domain channel estimation values on the paths.
22. The apparatus of claim 21 wherein said second determining module comprises:

    a calculation submodule, configured to calculate a conjugate of the first time domain channel estimation value for the first time domain channel estimation value and the second time domain channel estimation value in the time domain channel estimation values on the respective paths, Obtain a value;

    Determining a submodule, configured to multiply the value and the second time domain channel estimate to determine a frequency offset on the first path;

    The first time domain channel estimation value and the second time domain channel estimation value are time domain channel estimation values corresponding to different paths.
23. The apparatus of claim 21 further comprising:

    A tracking module is configured to perform automatic frequency tracking on the frequency offset.
24. The apparatus of claim 23 wherein said tracking module comprises:

    Determining a sub-module for determining a weighted average coefficient corresponding to each path;

    a calculation submodule, configured to calculate a weighted average value of the frequency offsets on the respective paths according to the weighted average coefficients corresponding to the paths and the frequency offsets on the respective paths;

    The tracking submodule is configured to perform automatic frequency tracking on the frequency offset averaged value.
25. A frequency offset estimating apparatus includes:

    a first obtaining module, configured to obtain time-frequency resources on each path;

    a second obtaining module, configured to perform an inverse fast Fourier transform IFFT on the time-frequency resources on the respective paths to obtain a time domain signal on each path;

    And a sending module, configured to send, to the receiving end, a time domain signal on each path.
26. A computer readable storage medium for storing a computer program, the computer program being executed by a processor to implement the steps of the method of any one of claims 1 to 9; or

    The steps in the method of claim 10 are implemented when the computer program is executed by a processor.

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