CN116074173A

CN116074173A - Signal detection method, device and equipment

Info

Publication number: CN116074173A
Application number: CN202310071953.6A
Authority: CN
Inventors: 方冬梅
Original assignee: Spreadtrum Communications Shanghai Co Ltd
Current assignee: Spreadtrum Communications Shanghai Co Ltd
Priority date: 2023-01-13
Filing date: 2023-01-13
Publication date: 2023-05-05

Abstract

The application provides a signal detection method, a signal detection device and signal detection equipment. The method comprises the following steps: interpolation processing is carried out on the frequency domain emission signals to obtain interpolated frequency domain emission signals; acquiring a first frequency domain signal corresponding to a first time domain received signal in a first Orthogonal Frequency Division Multiplexing (OFDM) demodulation window; acquiring a second frequency domain signal corresponding to a second time domain received signal in a second OFDM demodulation window; and determining a frequency offset estimation value according to the interpolated frequency domain transmission signal, the first frequency domain signal and the second frequency domain signal. The efficiency of determining the frequency offset estimation value is improved.

Description

Signal detection method, device and equipment

Technical Field

The present disclosure relates to the field of computer technologies, and in particular, to a signal detection method, apparatus, and device.

Background

Signals may be transmitted between the base station and the terminal device to communicate.

In the related art, a correlation value is generally determined using two or more received signals having a certain time interval and corresponding transmitted signals, and a frequency offset estimation value is determined according to the correlation value and the time interval. However, in the above procedure, when the received signal and the transmitted signal are comb-patterned signals and only a single orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM) symbol, the efficiency of determining the frequency offset estimate is low.

Disclosure of Invention

The application provides a signal detection method, a signal detection device and signal detection equipment, which are used for improving the efficiency of determining a frequency offset estimated value.

In a first aspect, the present application provides a signal detection method, the method comprising:

interpolation processing is carried out on the frequency domain emission signals to obtain interpolated frequency domain emission signals;

acquiring a first frequency domain signal corresponding to a first time domain received signal in a first Orthogonal Frequency Division Multiplexing (OFDM) demodulation window;

acquiring a second frequency domain signal corresponding to a second time domain received signal in a second OFDM demodulation window;

and determining a frequency offset estimation value according to the interpolated frequency domain transmission signal, the first frequency domain signal and the second frequency domain signal.

In one possible implementation, determining the frequency offset estimate from the interpolated frequency domain transmit signal, the first frequency domain signal, and the second frequency domain signal includes:

performing conjugate multiplication processing on the first frequency domain signal and the interpolated frequency domain transmitting signal to obtain a third frequency domain signal;

performing conjugate multiplication processing on the second frequency domain signal and the interpolated frequency domain transmitting signal to obtain a fourth frequency domain signal;

performing Inverse Fast Fourier Transform (IFFT) and merging processing on the third frequency domain signal and the fourth frequency domain signal to determine a time domain merging signal;

Determining a power delay spectrum PDP according to the time domain combined signals;

and determining the frequency offset estimation value according to the time domain combined signal and the PDP.

In one possible implementation, performing IFFT transformation and combining processing on the third frequency domain signal and the fourth frequency domain signal to determine a time domain combined signal, including:

n-processing the third frequency domain signal _FFT IFFT conversion of the point to obtain a first time domain signal;

n-processing the fourth frequency domain signal _FFT IFF of dotsT transformation is carried out to obtain a second time domain signal;

combining the front in the first time domain signal

The point and the front +_ in the second time domain signal>

Obtaining a time domain combined signal by a plurality of points;

wherein the N is _FFT FFT points for fast fourier transform within the OFDM demodulation window.

In one possible implementation manner, determining a power delay profile PDP according to the time domain combined signal includes:

if the minimum frequency of the frequency deviation range is larger than the first frequency threshold and the maximum frequency of the frequency deviation range is smaller than the second frequency threshold, N is determined _seg Linearly combining the time domain combined signals among the segments to obtain the PDP;

if the minimum frequency of the frequency deviation range is smaller than or equal to the first frequency threshold value or the maximum frequency of the frequency deviation range is larger than or equal to the second frequency threshold value, N is calculated _seg Nonlinear combination is carried out on the time domain combined signals among the segments to obtain the PDP;

wherein the N is _seg The number of segments of the frequency offset is calculated for segment correlation of a single OFDM symbol.

In one possible implementation manner, determining the frequency offset estimation value according to the time domain combined signal and the PDP includes:

in the PDP, the average power ratio is greater than Thr sigma ² The corresponding time domain sampling point index n is determined as the multipath tap position, the Thr is a threshold value, and the sigma ² Is the noise power;

calculating the N of the ith multipath tap _seg Correlation values of the time-domain combined signals of the segments, the i taking 0, &.. _path -1, said N _path Is the total number of multipath taps;

for N _Rx Each antenna, N _path Combining the correlation values among the multipath taps to obtain a correlation value combining result;

and determining a frequency offset estimation value according to the correlation value merging result.

In one possible embodiment, in the PDP, the average value of the total number of the cells is greater than thrσ ² Before the corresponding time domain sampling point index n is determined as the multipath tap position, the method further comprises:

determining K of valid signal occurrence in the time-domain combined signal _TC Intervals of K _TC The comb teeth are in the size;

at said N _FFT In the dot, remove the K _TC The points corresponding to the effective signals in each interval are counted to obtain a noise point set;

determining the noise power sigma from the set of noise points ² 。

In one possible implementation manner, the interpolation processing is performed on the frequency domain transmission signal to obtain an interpolated frequency domain transmission signal, which includes:

n-spacing _seg Extracting the frequency domain transmitting signals by subcarriers to obtain extracted frequency domain transmitting signals;

performing IFFT transformation and linear phase compensation on the extracted frequency domain transmitting signals to obtain first time domain transmitting signals;

supplementing the first time domain transmission signal with length

Obtaining a second time domain transmission signal;

and carrying out FFT (fast Fourier transform) on the second time domain transmitting signal to obtain the interpolated frequency domain transmitting signal.

n required for obtaining frequency domain cyclic convolution _tap A base sequence of dots, said N _tap Is an integer greater than or equal to 1;

and performing cyclic convolution processing on the base sequence and the frequency domain transmitting signal to obtain the interpolated frequency domain transmitting signal.

In one possible implementation, N required for the frequency domain cyclic convolution is obtained _tap A base sequence of points comprising:

generating a time sequence corresponding to a base sequence required by frequency domain cyclic convolution;

performing FFT (fast Fourier transform) on the time sequence to obtain a frequency domain sequence;

preserving N on both sides of the frequency domain sequence _tap And (3) obtaining the base sequence at a plurality of points.

In one possible implementation manner, acquiring a first frequency domain signal corresponding to a first time domain signal in a first OFDM demodulation window includes:

acquiring the first time domain receiving signal in the first OFDM demodulation window;

n to the first time domain receiving signal _FFT And carrying out FFT conversion on the points to obtain the first frequency domain signal.

In one possible implementation manner, acquiring a second frequency domain signal corresponding to a second time domain received signal in a second OFDM demodulation window includes:

shifting the first OFDM demodulation window backward

Obtaining the second OFDM demodulation window by a plurality of points;

acquiring the second time domain received signal in the second OFDM demodulation window;

n to the second time domain received signal _FFT And carrying out FFT conversion on the points to obtain the second frequency domain signal.

In a second aspect, embodiments of the present application provide a signal detection apparatus, the apparatus including: the device comprises a processing module, a first acquisition module, a second acquisition module and a determination module, wherein,

The processing module is used for carrying out interpolation processing on the frequency domain emission signals to obtain interpolated frequency domain emission signals;

the first acquisition module is used for acquiring a first frequency domain signal corresponding to a first time domain received signal in a first Orthogonal Frequency Division Multiplexing (OFDM) demodulation window;

the second obtaining module is configured to obtain a second frequency domain signal corresponding to a second time domain received signal in a second OFDM demodulation window;

the determining module is configured to determine a frequency offset estimation value according to the interpolated frequency domain transmission signal, the first frequency domain signal, and the second frequency domain signal.

In one possible implementation manner, the determining module is specifically configured to:

n-processing the fourth frequency domain signal _FFT IFFT conversion of the points to obtain a second time domain signal;

combining the front in the first time domain signal

The point and the front +_ in the second time domain signal>

Obtaining a time domain combined signal by a plurality of points;

wherein the N is _FFT For fast fourier transforms within OFDM demodulation windowFFT points.

In one possible implementation, the determining module is further configured to:

determining the noise power sigma from the set of noise points ² 。

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

Supplementing the first time domain transmission signal with length

Obtaining a second time domain transmission signal;

In one possible implementation manner, the first obtaining module is specifically configured to:

In one possible implementation manner, the second obtaining module is specifically configured to:

Shifting the first OFDM demodulation window backward

Obtaining the second OFDM demodulation window by a plurality of points;

In a third aspect, an embodiment of the present application provides a signal detection apparatus, including: a memory and a processor;

the memory stores computer-executable instructions;

the processor executing computer-executable instructions stored in the memory causes the processor to perform the signal detection method of any one of the first aspects.

In a fourth aspect, embodiments of the present application provide a computer-readable storage medium having stored therein computer-executable instructions for implementing the signal detection method of any one of the first aspects when the computer-executable instructions are executed by a processor.

In a fifth aspect, embodiments of the present application provide a computer program product comprising a computer program which, when executed by a processor, implements the signal detection method according to any one of the first aspects.

In a sixth aspect, embodiments of the present application provide a chip on which a computer program is stored, where the computer program, when executed by the chip, implements the signal detection method according to any one of the first aspects.

In a seventh aspect, the present application provides a chip module having a computer program stored thereon, which when executed by the chip module, implements the signal detection method according to any one of the first aspects.

The embodiment of the application provides a signal detection method, a device and equipment, wherein the signal detection equipment can conduct interpolation processing on a frequency domain emission signal to obtain an interpolated frequency domain emission signal. The signal detection device may obtain a first frequency domain signal corresponding to a first time domain received signal in a first OFDM demodulation window, and obtain a second frequency domain signal corresponding to a second time domain received signal in a second OFDM demodulation window. The signal detection device may determine the frequency offset estimate based on the interpolated frequency domain transmit signal, the first frequency domain signal, and the second frequency domain signal. Because the characteristics of the comb pattern in the frequency domain can be utilized to bring the characteristics of the segmentation weighting repetition of each OFDM symbol in the time domain for the signals with the characteristics of the comb pattern in the frequency domain, the efficiency of determining the frequency offset estimation value is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it will be obvious that the drawings in the following description are some embodiments of the present invention, and that other drawings can be obtained according to these drawings without inventive effort to a person skilled in the art.

FIG. 1 is a schematic diagram of a frequency domain comb pattern provided in an embodiment of the present application;

FIG. 2 is a signal diagram of segment weighted repetition according to an embodiment of the present application;

fig. 3 is a schematic diagram of an application scenario provided in an embodiment of the present application;

fig. 4 is a schematic flow chart of a signal detection method according to an embodiment of the present application;

fig. 5 is a flow chart of another signal detection method according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a signal detection device according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a signal detection device according to an embodiment of the present application.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as detailed in the accompanying claims.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In order to facilitate understanding of the technical solutions of the present application, concepts related to the present application will be explained first.

Inverse fast fourier transform (Inverse Fast Fourier Transform, IFFT) is a modulation technique that can be used to convert frequency domain signals to time domain signals.

The fast fourier transform (Fast Fourier Transform, FFT) is a demodulation technique that can be used to convert a time domain signal to a frequency domain signal.

OFDM technology is a multi-carrier modulation technique based on IFFT and FFT transforms. The signal may be divided into a plurality of sub-signals by OFDM technology, and a plurality of mutually orthogonal sub-carriers may be modulated with the plurality of sub-signals, respectively, to transmit the signal in parallel through the plurality of sub-carriers.

An OFDM symbol may include a plurality of subcarriers in a frequency domain, which are orthogonal to each other without affecting each other.

The frequency domain comb pattern means that the signal has a comb-like structure in the frequency domain.

Next, a frequency domain comb pattern will be described with reference to fig. 1.

Fig. 1 is a schematic diagram of a frequency domain comb pattern according to an embodiment of the present application. Referring to fig. 1, the horizontal axis represents the index number of an OFDM symbol in the time domain, and the vertical axis represents the index number of a subcarrier in the frequency domain. For any one time-frequency Resource Element (RE), one subcarrier corresponds to the frequency domain, and one OFDM symbol corresponds to the time domain.

A plurality of antenna ports may be included in the terminal device or the network device for transmitting signals.

Antenna port 0 and antenna port 1 may constitute code division multiplexing (Code Division Multiplexing, CDM) group 0 for code domain sharing. For example, within OFDM symbol 2, antenna port 0 may transmit signal 0 on

subcarriers

0, 2, 4, 6, 8, 10, antenna port 1 may transmit signal 1 on

subcarriers

0, 2, 4, 6, 8, 10, i.e., antenna port 0 and antenna port 1 may

multiplex subcarriers

0, 2, 4, 6, 8, 10, signal 1 and signal 0 may be orthogonal to each other without affecting each other.

Antenna port 2 and antenna port 3 may constitute CDM group 1 for code domain sharing. For example, within OFDM symbol 2, antenna port 2 may transmit signal 2 on

subcarriers

1, 3, 5, 7, 9, 11, antenna port 3 may transmit signal 3 on

subcarriers

1, 3, 5, 7, 9, 11, i.e., antenna port 2 and antenna port 3 may

multiplex subcarriers

1, 3, 5, 7, 9, 11, signal 2 and signal 3 may be orthogonal to each other without affecting each other.

For any one of the

signals

0, 1, 2 and 3, the signal structure of the signal in the frequency domain is Comb pattern, so as to meet the characteristic of the frequency domain Comb-2, namely, the signal is sent once every 2 subcarriers, and the signal can be weighted and repeated in 2 segments in the OFDM symbol 2 in the time domain.

Optionally, the signal satisfying the characteristic of frequency domain Comb-4 may be weighted and repeated in 4 segments in each OFDM symbol in the time domain; the signal satisfying the characteristic of frequency domain comb8 can be weighted and repeated in 8 segments in each OFDM symbol in the time domain.

Next, a description will be given of a segment weighted repetition with reference to fig. 2.

Fig. 2 is a schematic signal diagram of segment weighted repetition according to an embodiment of the present application. Referring to fig. 2, if the signal structure of the signal 1 in the frequency domain is a Comb pattern, the characteristics of the frequency domain Comb-2 are satisfied, it is assumed that the signal 1 in the time domain can be denoted as rt (n), n denotes an index of a sampling point in the time domain, n=0, … …, NN _FFT -1, rt (n) can be divided into 2 segments of length

Is a weighted repetition of the signal. Wherein N is _FFT The number of FFT points within an OFDM symbol. />

As shown in fig. 2, rt (n) may be divided into 2 segments, segment 1 and segment 2, respectively. Wherein the signal length of both segment 1 and segment 2 is

The signals corresponding to segment 1 and segment 2 are weight repeated. For example, if the number of FFT points in an OFDM symbol is 64 points, N _FFT For 64, signal 1 may be represented in the time domain as rt (n), n=0, … …,63. If signal 1 is divided into 2 segments, then 64/2=32 points may be included in the corresponding signal for each segment.

Next, an application scenario of the embodiment of the present application will be described with reference to fig. 3.

Fig. 3 is a schematic diagram of an application scenario provided in an embodiment of the present application. Referring to fig. 3, a network device 101 and a terminal device 102 are included. The network device 101 and the terminal device 102 may communicate with each other. For example, the network device 101 may be a base station, and the terminal device 102 may be a mobile phone.

The network device 101 may transmit demodulation reference signals (Demodulation Reference Signal, DMRS) to the terminal device 102 over a physical downlink shared channel (Physical Downlink Share Channel, PDSCH). The terminal device 102 may transmit DMRS, or uplink sounding reference signals (Sounding Reference Signal, SRS), to the network device 101 over a physical uplink shared channel (Physical Uplink Shared Channel, PUSCH).

Wherein PDSCH DMRS, PUSCH DMRS and SRS are all signals with a frequency domain comb pattern.

When the network device 101 transmits a signal, the network device 101 is a transmitting end, and the terminal device 102 is a receiving end; when the terminal device 102 transmits a signal, the terminal device 102 is a transmitting end, and the network device 101 is a receiving end. The signal transmitted by the transmitting end may be referred to as a transmitting signal, and the signal received by the receiving end may be referred to as a receiving signal.

In the related art, it is generally possible to determine a correlation value using two or more received signals having a certain time interval and corresponding transmitted signals, and determine a frequency offset estimation value according to the correlation value and the time interval. However, in the above procedure, when the received signal and the transmitted signal are signals having the characteristics of a frequency domain comb pattern and only a single OFDM symbol, the efficiency of determining the frequency offset estimation value is low.

In this embodiment of the present application, interpolation processing may be performed on the frequency domain transmission signal to obtain an interpolated frequency domain transmission signal, and a first frequency domain signal corresponding to a first time domain reception signal in a first OFDM demodulation window and a second frequency domain signal corresponding to a second time domain reception signal in a second OFDM demodulation window are obtained. The frequency offset estimate may be determined from the interpolated frequency domain transmit signal, the first frequency domain signal, and the second frequency domain signal. Because the characteristics of the comb pattern in the frequency domain can be utilized to bring the characteristics of the segmentation weighting repetition of each OFDM symbol in the time domain for the signals with the characteristics of the comb pattern in the frequency domain, the efficiency of determining the frequency offset estimation value is improved.

The technical scheme shown in the application is described in detail through specific embodiments. It should be noted that the following embodiments may exist alone or in combination with each other, and for the same or similar content, the description will not be repeated in different embodiments.

Fig. 4 is a flow chart of a signal detection method according to an embodiment of the present application. Referring to fig. 4, the method may include:

s401, carrying out interpolation processing on the frequency domain emission signals to obtain the interpolated frequency domain emission signals.

The execution body of the embodiment of the application may be a signal detection device, or may be a chip, a chip module, or a signal detection apparatus that is disposed in the signal detection device. The signal detection means may be implemented by software or by a combination of software and hardware. The signal detection means may be a processor in signal detection. The signal detection device may be a network device or a terminal device as shown in fig. 1. For ease of understanding, hereinafter, an example will be described in which an execution body is a signal detection device.

In an alternative embodiment, the frequency domain transmission signal may be interpolated by: n-spacing _seg Extracting frequency domain transmitting signals by subcarriers to obtain extracted frequency domain transmitting signals; performing IFFT conversion and linear phase compensation on the extracted frequency domain transmitting signals to obtain first time domain transmitting signals; supplementing the first time domain transmission signal with length

Obtaining a second time domain transmission signal; and carrying out FFT (fast Fourier transform) on the second time domain transmission signal to obtain an interpolated frequency domain transmission signal.

Wherein N is _seg Representing the number of segments by which a single OFDM symbol is segment-wise correlated to a frequency offset. Number of segments N _seg Can be N _FFT And K _TC Is not 1 cm divisor, and the number of segments N _seg May be selected to meet the required frequency offset estimation range. N (N) _FFT For FFT points within OFDM symbols, K _TC Is the size of comb teeth. For example, if N _FFT At 64 points, K _TC 8 points, then N _seg May be 2, meaning that a single OFDM symbol may be divided into 2 segments.

Let the frequency domain transmit signal be r (k), where k denotes the index of the subcarrier, k=0, …, N _FFT -1. For the frequency domain transmit signal r (k), only at sub-carrier k=k _start +K _TC *k′+k _offset ，k′＝0，…，M _sc There is a value on-1 and the value on the remaining subcarriers k is 0.

Wherein k is _start Representing a transmit signal initiation RE; k (K) _TC Representing the comb tooth size of the frequency domain comb pattern; k (k) _offset An offset, k, representing the transmitted RE of the OFDM symbol _offset The value range of (2) is 0-k _offset ＜K _Tc ；M _sc Representing the effective length of the transmitted signal sequence; k' represents the transmit signal index.

Let the index of each segment be n _seg Then n _seg The value range of (c) is 0 _seg -1。

Alternatively, N may be isolated by the following formula (1) _seg Sub-carrier wave extracting frequency domain transmitting signal to obtain extracted frequency domain transmitting signal r _ext (k)：

r _ext (k)＝r(k*N _seg +(k _start +k _offset )mod N _seg ) Formula (1)

Wherein, the liquid crystal display device comprises a liquid crystal display device,

obtaining the extracted frequency domain transmitting signal r _ext (k) Thereafter, the extracted frequency domain transmission signal r can be subjected to _ext (k) Doing the following steps

IFFT transforming the point to obtain the corresponding time domain transmission signal rt _ext (n) wherein, _>

Alternatively, the time domain transmit signal rt may be calculated by equation (2) _ext (n) performing linear phase compensation to obtain a first time domain transmit signal

j represents an imaginary unit, i.e. +.>

Other parameter explanations are provided above.

Alternatively, the signal may be transmitted in a first time domain

Signal tail of (2) with complementary length of

And obtaining a second time domain transmission signal. N can be performed on the second time domain transmission signal _FFT FFT conversion of the points to obtain an interpolated frequency domain transmission signal rf _os (k) A. The invention relates to a method for producing a fibre-reinforced plastic composite Wherein k=0, …, N _FFT -1 the interpolated frequency domain transmit signal rf _os (k) Equivalent to the extracted frequency domain transmission signal r _ext (k) Frequency shift and N _seg The double oversampling is also equivalent to interpolating the original frequency domain transmit signal r (k).

S402, acquiring a first frequency domain signal corresponding to a first time domain received signal in a first OFDM demodulation window.

At least one OFDM symbol may be included in the OFDM demodulation window.

In an alternative embodiment, the first frequency domain signal corresponding to the first time domain signal in the first OFDM demodulation window may be acquired by: acquiring a first time domain receiving signal in a first OFDM demodulation window; n for first time domain received signal _FFT And carrying out FFT conversion on the points to obtain a first frequency domain signal.

Let n _Rx The time domain received signal of the nth time domain sampling point of the receiving antenna is y (n _Rx N), where n _Rx ＝0，…，N _Rx -1；n＝0，1，…；N _Rx Is the number of receiving antennas.

For any antenna, the receiving symbol of the antenna may be taken from the Cyclic Prefix (CP) to obtain N in the first OFDM demodulation window _FFT First time domain received signal y of point ₁ (n _Rx N). Wherein n is _Rx ＝0，…，N _Rx -1；n＝0，…，N _FFT -1。

Alternatively, in order that the first OFDM demodulation window may contain the first few more powerful multipath complete OFDM symbols, the first OFDM demodulation window may be suitably advanced by several points, N in total _FFT Multiple points to obtain N _FFT First time domain received signal y of each point ₁ (n _Rx ，n)。

Can receive a signal y for a first time domain ₁ (n _Rx N), N is _FFT FFT transforming the points to obtain a first frequency domain signal Y ₁ (n _Rx K). Wherein n is _Rx ＝0，…，N _Rx -1，N _Rx The number of the receiving antennas; k=0, …, N _FFT -1。

S403, obtaining a second frequency domain signal corresponding to the second time domain received signal in the second OFDM demodulation window.

In an alternative embodiment, the obtaining the second frequency domain signal corresponding to the second time domain received signal in the second OFDM demodulation window may include: shift the first OFDM demodulation window backward by N _FFT 2 points to obtain a second OFDM demodulation window; acquiring a second time domain received signal in a second OFDM demodulation window; n is carried out on the second time domain received signal _FFT And carrying out FFT conversion on the points to obtain a second frequency domain signal.

Optionally, the OFDM demodulation window is moved backward

Dots, i.e. from->

Point starts to get N backwards _FFT A point for acquiring a second time domain received signal y ₂ (n _Rx N), where n _Rx ＝0，…，N _Rx -1；n＝0，…，N _FFT -1。

Can receive the signal y for the second time domain ₂ (n _Rx N), N is _FFT FFT transform of the points to obtainTo the second frequency domain signal Y ₂ (n _Rx K). Wherein n is _Rx ＝0，…，N _Rx -1；k＝0，…，N _FFT -1。

S404, determining a frequency offset estimation value according to the interpolated frequency domain transmission signal, the first frequency domain signal and the second frequency domain signal.

In an alternative embodiment, the frequency offset estimate may be determined by: performing conjugate multiplication processing on the first frequency domain signal and the interpolated frequency domain transmitting signal to obtain a third frequency domain signal; performing conjugate multiplication processing on the second frequency domain signal and the interpolated frequency domain transmitting signal to obtain a fourth frequency domain signal; performing Inverse Fast Fourier Transform (IFFT) and merging processing on the third frequency domain signal and the fourth frequency domain signal to determine a time domain merging signal; determining a power delay spectrum PDP according to the time domain combined signals; and determining a frequency offset estimation value according to the time domain combined signal and the PDP.

Alternatively, the first frequency domain signal Y may be calculated by equation (3) ₁ (n _Rx K) and interpolated frequency domain transmit signal rf _os (k) Corresponding point multiplication is carried out on the conjugate of the third frequency domain signal H ₁ (n _Rx ，k)：

H ₁ (n _Rx ，k)＝Y ₁ (n _Rx ，k)*conj(rf _os (k) Formula (3)

Wherein n is _Rx ＝0，…，N _Rx -1；k＝0，…，N _FFT -1。

Alternatively, the second frequency domain signal Y may be processed by equation (4) ₂ (n _Rx K) and interpolated frequency domain transmit signal rf _os (k) Corresponding point multiplication is carried out on the conjugate of the frequency domain signal to obtain a fourth frequency domain signal H ₂ (n _Rx ，k)：

H ₂ (n _Rx ，k)＝Y ₂ (n _Rx ，k)*conj(rf _os (k) Formula (4)

Wherein n is _Rx ＝0，…，N _Rx -1；k＝0，…，N _FFT -1。

Optionally, a third frequency domain signal H is obtained ₁ (n _Rx K) and a fourth frequency domain signal H ₂ (n _Rx After k), the third frequency domain signal H can be processed ₁ (n _Rx Performing IFFT transformation on k) to obtain a first time domain signal; can be applied to the fourth frequency domain signal H ₂ (n _Rx And k) performing IFFT transformation to obtain a second time domain signal. The first time domain signal and the second time domain signal may be combined to determine a time domain combined signal, and further determine a power delay profile (Power Delay Profile, PDP) based on the time domain combined signal, and determine a frequency offset estimate based on the time domain combined signal and the PDP.

In the embodiment of the application, the signal detection device may perform interpolation processing on the frequency domain transmission signal to obtain an interpolated frequency domain transmission signal. The signal detection device may obtain a first frequency domain signal corresponding to a first time domain received signal in a first OFDM demodulation window, and obtain a second frequency domain signal corresponding to a second time domain received signal in a second OFDM demodulation window. The signal detection device may determine the frequency offset estimate based on the interpolated frequency domain transmit signal, the first frequency domain signal, and the second frequency domain signal. Because the characteristics of the comb pattern in the frequency domain can be utilized to bring the characteristics of the segmentation weighting repetition of each OFDM symbol in the time domain for the signals with the characteristics of the comb pattern in the frequency domain, the calculated amount of calculating the frequency offset estimation value is simplified, and the efficiency of determining the frequency offset estimation value is improved.

Next, the above-described signal detection method will be described in further detail with reference to fig. 5, based on the embodiment shown in fig. 4.

Fig. 5 is a flow chart of another signal detection method according to an embodiment of the present application. Referring to fig. 5, the method may include:

s501, carrying out interpolation processing on the frequency domain emission signals to obtain the interpolated frequency domain emission signals.

Optionally, performing interpolation processing on the frequency domain transmission signal to obtain an interpolated frequency domain transmission signal, which may include the following 2 modes:

mode 1: can separate N _seg Extracting frequency domain transmitting signals by sub-carriers to obtain extracted frequency domain transmitting signals, performing IFFT transformation and linear phase compensation on the extracted frequency domain transmitting signals,obtaining a first time domain transmitting signal and supplementing the first time domain transmitting signal with a length of

And (2) obtaining a second time domain transmitting signal, and further performing FFT (fast Fourier transform) on the second time domain transmitting signal to obtain an interpolated frequency domain transmitting signal.

It should be noted that, the execution process of the mode 1 may refer to the execution process of the step S401, and will not be described herein.

Mode 2: can obtain N required by frequency domain cyclic convolution _tap And (3) carrying out cyclic convolution processing on the base sequence of the point and the frequency domain transmitting signal to obtain an interpolated frequency domain transmitting signal.

N _tap May be an integer greater than or equal to 1.

In an alternative embodiment, the N required for the frequency domain cyclic convolution may be obtained by _tap Base sequence of dots: generating a time sequence corresponding to a base sequence required by frequency domain cyclic convolution; performing FFT (fast Fourier transform) on the time sequence to obtain a frequency domain sequence; preserving N on both sides of the frequency domain sequence _tap And (3) obtaining a base sequence at each point.

Alternatively, the timing sequence sinc corresponding to the base sequence required for the frequency domain cyclic convolution may be generated by the following formula (5) _t (n)：

Alternatively, the time series sinc may be _t (n) FFT transforming to obtain frequency domain sequence sinc _f (k) Wherein k=0, …, N _FFT -1。

Alternatively, the frequency domain sequence sinc may be preserved by the following equation (6) _f (k) N on both sides _tap At several points, the base sequence coef (k) is obtained:

alternatively, N required for the frequency domain cyclic convolution may be generated in advance _tap The base sequence coef (k) of dots is stored.

N required for obtaining frequency domain cyclic convolution _tap After the base sequence coef (k) of points, the decimated frequency domain transmit signal r can be calculated by the following equation (7) _ext (k) Every N _seg Zero is inserted in the middle of each RE to obtain a frequency domain transmitting signal r with zero inserted _zp (k)：

Alternatively, the signal r may be transmitted for the base sequence coef (k) and the frequency domain of zero insertion _zp (k) Performing cyclic convolution processing to obtain interpolated frequency domain transmitting signal rf _os (k)。

In mode 2, an interpolated frequency domain transmit signal rf is generated _os (k) In the process of (2), r can be _ext (k) With local N _tap The base sequence of points coef (k) is convolved circularly, and N _tap A substantial part of the elements in the base sequence coef (k) of the dot is 0, and the frequency domain of the zero inserted transmitted signal r _zp (k) M alone _sc The number is not 0, and compared with the mode 1, the calculation amount is further reduced, and the calculation process is simplified.

S502, a first frequency domain signal corresponding to a first time domain received signal in a first OFDM demodulation window is obtained.

It should be noted that, the execution process of step S502 may refer to step S402, and will not be described herein.

S503, obtaining a second frequency domain signal corresponding to a second time domain received signal in a second OFDM demodulation window.

It should be noted that, the execution process of step S503 may refer to step S403, and will not be described herein.

S504, performing conjugate multiplication processing on the first frequency domain signal and the interpolated frequency domain transmitting signal to obtain a third frequency domain signal.

Alternatively, the first frequency domain signal Y may be calculated by the above formula (3) ₁ (n _Rx K) and interpolated frequency domain transmit signal rf _os (k) Corresponding point multiplication is carried out on the conjugate of the third frequency domain signal H ₁ (n _Rx ，k)。

S505, performing conjugate multiplication processing on the second frequency domain signal and the interpolated frequency domain transmitting signal to obtain a fourth frequency domain signal.

Alternatively, the second frequency domain signal Y may be calculated by the above formula (4) ₂ (n _Rx K) and interpolated frequency domain transmit signal rf _os (k) Corresponding point multiplication is carried out on the conjugate of the frequency domain signal to obtain a fourth frequency domain signal H ₂ (n _Rx ，k)。

S506, performing IFFT transformation and combination processing on the third frequency domain signal and the fourth frequency domain signal to determine a time domain combined signal.

In an alternative embodiment, the time-domain combined signal may be determined by: n to the third frequency domain signal _FFT IFFT conversion of the point to obtain a first time domain signal; n is carried out on the fourth frequency domain signal _FFT IFFT conversion of the points to obtain a second time domain signal; combining the front in the first time domain signal

The point and the front +_ in the second time domain signal>

And (3) obtaining a time domain combined signal.

Alternatively, the third frequency domain signal H may be ₁ (n _Rx K) N is carried out _FFT IFFT transforming the points to obtain a first time domain signal h ₁ (n _Rx ，n)，n _Rx ＝0，…，N _Rx -1；n＝0，…，N _FFT -1。

Alternatively, the fourth frequency domain signal H may be ₂ (n _Rx K) N is carried out _FFT IFFT transforming the points to obtain a second time domain signal h ₂ (n _Rx ，n)，n _Rx ＝0，…，N _Rx -1；n＝0，…，N _FFT -1。

In an alternative embodiment, the first time may be determined by equation (8)Domain signal h ₁ (n _Rx Front of n)

A point and a second time domain signal h ₂ (n _Rx Front ∈n)>

The points are pieced together to obtain a time domain combined signal h _comb (n _Rx ，n)：

S507, determining a power delay spectrum PDP according to the time domain combined signals.

Alternatively, determining the power delay profile PDP may comprise 2 cases:

case 1: if the minimum frequency of the frequency offset range is greater than the first frequency threshold, and the maximum frequency of the frequency offset range is less than the second frequency threshold.

In this case, then, N of the same antenna can be used _seg Time-domain combined signal h between segments _comb (n _Rx And n) carrying out linear combination to obtain the PDP.

Specifically, N of the same antenna can be determined by the formula (9) _seg The time domain combined signals among the segments are linearly combined to obtain a power delay spectrum PDP (n) _Rx ，n)：

Wherein n is _Rx ＝0，…，N _Rx -1；n＝0，…，N _CP -1，N _CP The CP number represents an OFDM symbol.

Case 2: if the minimum frequency of the frequency offset range is smaller than or equal to the first frequency threshold value, or the maximum frequency of the frequency offset range is larger than or equal to the second frequency threshold value.

In this case, thenN can be N _seg And carrying out nonlinear combination on the time domain combined signals among the segments to obtain the PDP.

Specifically, N of the same antenna can be calculated by the formula (10) _seg Time-domain combined signal h between segments _comb (n _Rx Non-linear combination is carried out on the n) to obtain a power delay spectrum PDP (n) _Rx ，n)：

S508, determining a frequency offset estimation value according to the time domain combined signal and the PDP.

In an alternative embodiment, the frequency offset estimate may be determined from the time domain combined signal and PDP by: in PDP, will be greater than Thr sigma ² The corresponding time domain sampling point index n is determined as a multipath tap position; calculating N of ith multipath tap _seg Correlation values of the time-domain combined signals of the segments; for N _Rx Each antenna, N _path Combining the correlation values among the multipath taps to obtain a correlation value combining result;

Wherein Thr is a threshold value, and can be determined according to the false alarm rate. Will N _seg Non-linear combination of time domain combined signals between segments and N _seg The threshold value Thr is different when the time domain combined signals between the segments are combined linearly.

σ ² Representing the noise power. Alternatively, the noise power σ may be determined by ² : determining K of valid signal occurrence in time-domain combined signal _TC Each interval; at N _FFT In the dot, K is removed _TC The number of points corresponding to the effective signals in each interval is obtained to obtain a noise point set; determining noise power sigma from a set of noise points ² 。

Assuming that multipath energy is concentrated at the CP position of an OFDM symbol, N _CP The number of CP points for the OFDM symbol can be regarded as combining the signal h in the time domain _comb (n _Rx In n), effective signal energy

Appear at K _TC In each interval, it can be expressed by the formula (11):

wherein k is _TC ＝0，…，K _TC -1。

Let it be at N _FFT The K is removed from the time domain points _TC Effective signal energy of individual intervals

The remaining points are the noise sample point set ψ _noise The number of elements in the noise sample point set is N _noise The noise power sigma can be calculated by the formula (12) ² ：

Alternatively, in PDP, more than thrσ may be used ² The corresponding time domain sampling point index n is determined as the multipath tap position

Wherein n is _Rx ＝0，…，N _Rx -1；i＝0，…，N _path -1。

In an alternative embodiment, N for the ith multipath tap may be calculated by equation (13) as follows _seg Time-domain combined signal h of each segment _comb (n _Rx The pairwise correlation value corr (n) _Rx ，i)：

Wherein n is _Rx ＝0，…，N _Rx -1; i denotes the index of the multipath tap, i=0, …, N _path -1，N _path Is the total number of multipath taps; other parameter explanations can be found above.

Alternatively, N can be determined by 2 ways _Rx Each antenna, N _path Correlation value corr (n) between multipath taps _Rx And i) carrying out combination processing to obtain a correlation value combination result:

mode 1: can be applied to N _Rx Each antenna, N _path Correlation value corr (n) between multipath taps _Rx I) performing equal gain combining processing.

Alternatively, N may be calculated by equation (14) _Rx Each antenna, N _path Correlation value corr (n) between multipath taps _Rx I) performing equal gain combination processing to obtain a correlation value combination result corr _sum ：

Mode 2: can be applied to N _Rx Each antenna, N _path Correlation value corr (n) between multipath taps _Rx I) performing maximum ratio combining processing.

Alternatively, N may be calculated by equation (15) _Rx Each antenna, N _path Correlation value corr (n) between multipath taps _Rx I) performing equal maximum ratio combining processing to obtain a correlation value combining result corr _sum ：

Wherein the factor w (n _Rx I) and a correlation value corr (n) _Rx The signal to noise ratio of i) is proportional.

Alternatively, the method may be performed by the formula (16) or the formula (17),calculated, the weighted combined factor w (n _Rx ，i)：

Wherein SNR (n _Rx I) represents the nth _Rx Signal-to-noise ratio SNR of the signal of the i-th multipath tap.

Alternatively, the frequency offset estimation value FO may be determined according to the correlation value combining result by the formula (18):

if there are other signals on other comb teeth of the RB where the transmission signal is located or other ports of the comb teeth, an interference cancellation (Interference cancellation, IC) algorithm may be used to estimate the other signals at the receiving end, and then receive the signal y (n _Rx Subtracting from n), and determining the frequency offset estimation value in the mode.

In the embodiment of the application, the signal detection device may perform interpolation processing on the frequency domain transmission signal to obtain an interpolated frequency domain transmission signal. The signal detection device may obtain a first frequency domain signal corresponding to a first time domain received signal in a first OFDM demodulation window and a second frequency domain signal corresponding to a second time domain received signal in a second OFDM demodulation window. The signal detection device may perform conjugate multiplication processing on the first frequency domain signal and the interpolated frequency domain transmission signal to obtain a third frequency domain signal; performing conjugate multiplication processing on the second frequency domain signal and the interpolated frequency domain transmitting signal to obtain a fourth frequency domain signal; and the third frequency domain signal and the fourth frequency domain signal can be subjected to IFFT transformation and combination processing to determine a time domain combined signal, and then the power delay spectrum PDP can be determined according to the time domain combined signal. Finally, the frequency offset estimation value can be determined according to the time domain combined signal and the PDP. Because the characteristics of the comb pattern in the frequency domain can be utilized to bring the characteristics of the segmentation weighting repetition of each OFDM symbol in the time domain for the signals with the characteristics of the comb pattern in the frequency domain, the efficiency of determining the frequency offset estimation value is improved.

Fig. 6 is a schematic structural diagram of a signal detection device according to an embodiment of the present application. The signal detection device can be a chip or a chip module. Referring to fig. 6, the signal detection apparatus 10 may include: a processing module 11, a first acquisition module 12, a second acquisition module 13 and a determination module 14, wherein,

The processing module 11 is configured to perform interpolation processing on the frequency domain transmission signal to obtain an interpolated frequency domain transmission signal;

the first obtaining module 12 is configured to obtain a first frequency domain signal corresponding to a first time domain received signal in a first orthogonal frequency division multiplexing OFDM demodulation window;

the second obtaining module 13 is configured to obtain a second frequency domain signal corresponding to a second time domain received signal in a second OFDM demodulation window;

the determining module 14 is configured to determine a frequency offset estimation value according to the interpolated frequency domain transmission signal, the first frequency domain signal, and the second frequency domain signal.

The signal detection device provided in the embodiment of the present application may execute the technical solution shown in the foregoing method embodiment, and its implementation principle and beneficial effects are similar, and will not be described herein again.

In one possible implementation, the determining module 14 is specifically configured to:

combining the front in the first time domain signal

The point and the front +_ in the second time domain signal>

Obtaining a time domain combined signal by a plurality of points;

in the PDP, will be larger thanThr*σ ² The corresponding time domain sampling point index n is determined as the multipath tap position, the Thr is a threshold value, and the sigma ² Is the noise power;

In one possible implementation, the determining module 14 is further configured to:

determining the noise power sigma from the set of noise points ² 。

In one possible embodiment, the processing module 11 is specifically configured to:

supplementing the first time domain transmission signal with length

Obtaining a second time domain transmission signal; />

In one possible implementation, the first obtaining module 12 is specifically configured to:

In a possible embodiment, the second obtaining module 13 is specifically configured to:

shifting the first OFDM demodulation window backward

Obtaining the second OFDM demodulation window by a plurality of points;

Referring to fig. 7, the signal detection apparatus 20 may include a processor 21 and a memory 22. The processor 21, the memory 22, and the like are illustratively interconnected by a bus 23.

The memory 22 stores computer-executable instructions;

the processor 21 executes computer-executable instructions stored in the memory 22, causing the processor 21 to perform the signal detection method as shown in the method embodiments described above.

All or part of the steps for implementing the method embodiments described above may be performed by hardware associated with program instructions. The foregoing program may be stored in a readable memory. The program, when executed, performs steps including the method embodiments described above; and the aforementioned memory (storage medium) includes: read-only memory (ROM), RAM, flash memory, hard disk, solid state disk, magnetic tape, floppy disk, optical disk, and any combination thereof.

Embodiments of the present application provide a computer readable storage medium having stored therein computer executable instructions for implementing the signal detection method described in the above method embodiments when the computer executable instructions are executed by a processor.

Embodiments of the present application may also provide a computer program product, which includes a computer program, where the computer program can implement the signal detection method shown in the foregoing method embodiments when executed by a processor.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the embodiments of the present application fall within the scope of the claims and the equivalents thereof, the present application is intended to encompass such modifications and variations.

In the present application, the term "include" and variations thereof may refer to non-limiting inclusion; the term "or" and variations thereof may refer to "and/or". The terms "first," "second," and the like in this application are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. In the present application, "plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship.

Claims

1. A method of signal detection, the method comprising:

2. The method of claim 1, wherein determining a frequency offset estimate from the interpolated frequency domain transmit signal, the first frequency domain signal, and the second frequency domain signal comprises:

3. The method of claim 2 wherein performing IFFT transformation and combining processing on the third frequency domain signal and the fourth frequency domain signal to determine a time domain combined signal comprises:

combining the front in the first time domain signal

The point and the front +_ in the second time domain signal>

Obtaining a time domain combined signal by a plurality of points;

4. The method of claim 2, wherein determining a power delay profile PDP from the time domain combined signal comprises:

5. The method of any of claims 2-4, wherein determining the frequency offset estimate from the time domain combined signal and the PDP comprises:

calculating the N of the ith multipath tap _seg Correlation values of the time-domain combined signals of the segments, wherein i is 0, … … and N _path -1, said N _path Is the total number of multipath taps;

6. The method according to claim 5, wherein in the PDP, more than thrσ is to be used ² Before the corresponding time domain sampling point index n is determined as the multipath tap position, the method further comprises:

at the position ofThe N is _FFT In the dot, remove the K _TC The points corresponding to the effective signals in each interval are counted to obtain a noise point set;

determining the noise power sigma from the set of noise points ² 。

7. The method according to any one of claims 1-6, wherein interpolating the frequency domain transmit signal to obtain an interpolated frequency domain transmit signal comprises:

supplementing the first time domain transmission signal with length

Obtaining a second time domain transmission signal;

8. The method according to any one of claims 1-6, wherein interpolating the frequency domain transmit signal to obtain an interpolated frequency domain transmit signal comprises:

9. The method of claim 8, wherein N required for the frequency domain cyclic convolution is obtained _tap A base sequence of points comprising:

10. The method according to any one of claims 1-9, wherein obtaining a first frequency domain signal corresponding to a first time domain signal within a first OFDM demodulation window comprises:

11. The method according to any one of claims 1-10, wherein obtaining a second frequency domain signal corresponding to a second time domain received signal within a second OFDM demodulation window comprises:

shifting the first OFDM demodulation window backward

Obtaining the second OFDM demodulation window by a plurality of points;

12. A signal detection apparatus, comprising: the device comprises a processing module, a first acquisition module, a second acquisition module and a determination module, wherein,

13. A signal detection apparatus, comprising: a memory and a processor;

the memory stores computer-executable instructions;

the processor executing computer-executable instructions stored in the memory, causing the processor to perform the signal detection method of any one of claims 1 to 11.

14. A computer readable storage medium having stored therein computer executable instructions for implementing the signal detection method of any of claims 1 to 11 when the computer executable instructions are executed by a processor.

15. A computer program product comprising a computer program which, when executed by a processor, implements the signal detection method of any one of claims 1 to 11.