CN117320046B - CRS searching method, LTE time alignment error measuring method and user equipment - Google Patents
CRS searching method, LTE time alignment error measuring method and user equipment Download PDFInfo
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Abstract
A CRS searching method, an LTE time alignment error measuring method and user equipment, wherein the CRS searching method carries out correlation calculation on a generated CRS reference signal and a second sampling signal by adopting a fast Fourier recursive algorithm in a frequency domain so as to search an actual delay position of a CRS in the second sampling signal to obtain the actual delay position of the CRS transmitted by each antenna port in a physical cell, so that interference of other downlink signals transmitted on subcarriers unused by the CRS on a correlation calculation result during time domain correlation calculation can be avoided, the CRS can be searched more accurately, and occupied operation resources are less.
Description
Technical Field
The present disclosure relates to the field of wireless communications technologies, and in particular, to a CRS search method, an LTE time alignment error measurement method, and a user equipment.
Background
The LTE protocol is based on an OFDM modulation technique, and provides for data transmission in units of radio signal frames (frames) in the time domain, each radio signal Frame being fixed to have a length of 10ms. Before LTE communication, the user equipment realized based on the LTE protocol must complete physical cell search and synchronization to acquire the starting moment of a wireless signal frame so as to realize time synchronization of the transceiver equipment.
In the field of base station testing, in order to independently test performance parameters of a single antenna in a multi-antenna communication scenario, a receiving end needs to perform wireless signal frame synchronization according to data acquired by the single receiving antenna. Considering that protocol 3GPP TS 36.211 6.11 specifies that the receiving device does not presuppose the transmit antenna port of the synchronization signal, wireless signal frame synchronization using CRS may be considered at this time. The synchronization of the wireless signal frame and the measurement of the time alignment error by using the CRS all need to search the time delay position of the CRS from the sampling signal, and then the time domain position of the CRS in the wireless signal frame is regulated according to a protocol to position the starting moment of the wireless signal frame.
Thus, there is a need to quickly and accurately search for the delay position of CRS.
Disclosure of Invention
The technical problem that this application mainly solves is how to search for the delay position of CRS more fast, accurately.
According to a first aspect, in one embodiment, there is provided an LTE-based CRS search method, including:
receiving an LTE signal sent by a base station to be detected, and intercepting a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length;
searching PSS in the first sampling signal, and calculating the delay position of the frame head of the wireless signal frame in the first sampling signal according to the delay position of the searched PSS in the first sampling signal; determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal;
searching an SSS sequence in the first sampling signal according to a delay position of the SSS specified by a preset protocol, and determining a physical cell identifier corresponding to the base station to be detected according to the searched PSS sequence and the SSS sequence; according to the physical cell identification, a CRS reference signal is obtained;
selecting a positioning time slot from the first sampling signal according to the ideal delay position of the CRS, wherein the positioning time slot at least comprises the ideal delay position of the CRS; intercepting a signal with a second time length in the positioning time slot by taking an ideal delay position of the CRS as a center to serve as a second sampling signal;
and in the second sampling signal, performing correlation calculation based on a frequency domain by using the CRS reference signal to obtain an actual delay position of the CRS in the second sampling signal so as to obtain the actual delay position of the CRS transmitted by each antenna port in the physical cell.
According to a second aspect, in one embodiment, there is provided an LTE time alignment error measurement method, including:
receiving an LTE signal sent by a base station to be detected, and intercepting a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length;
searching PSS in the first sampling signal, and calculating the delay position of the frame head of the wireless signal frame in the first sampling signal according to the delay position of the searched PSS in the first sampling signal; determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal;
searching an SSS sequence in the first sampling signal according to a delay position of the SSS specified by a preset protocol, and determining a physical cell identifier corresponding to the base station to be detected according to the searched PSS sequence and the SSS sequence; according to the physical cell identification, a CRS reference signal is obtained;
selecting a positioning time slot from the first sampling signal according to the ideal delay position of the CRS, wherein the positioning time slot at least comprises the ideal delay position of the CRS; intercepting a signal with a second time length in the positioning time slot by taking an ideal delay position of the CRS as a center to serve as a second sampling signal;
in the second sampling signal, performing correlation calculation based on a frequency domain by using the CRS reference signal to obtain an actual delay position of a CRS in the second sampling signal so as to obtain the actual delay position of the CRS transmitted by each antenna port in the physical cell;
and determining the time alignment error between the CRS and the base station to be detected according to the actual delay positions of the CRS transmitted by each antenna port.
According to a third aspect, there is provided in an embodiment a user equipment comprising:
the sampling unit is used for receiving the LTE signal sent by the base station to be detected, and intercepting a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length;
the CRS ideal delay position acquisition unit is used for searching the PSS in the first sampling signal and calculating the delay position of the frame head of the wireless signal frame in the first sampling signal according to the delay position of the searched PSS in the first sampling signal; determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal;
a CRS reference signal acquisition unit, configured to search an SSS sequence in the first sampling signal according to a delay position of the SSS specified by a preset protocol, and determine a physical cell identifier corresponding to the base station to be detected according to the searched PSS sequence and SSS sequence; according to the physical cell identification, a CRS reference signal is obtained;
the intercepting unit is used for selecting a positioning time slot from the first sampling signal according to the ideal delay position of the CRS, wherein the positioning time slot at least comprises the ideal delay position of the CRS; intercepting a signal with a second time length in the positioning time slot by taking an ideal delay position of the CRS as a center to serve as a second sampling signal;
and the searching unit is used for carrying out frequency domain-based correlation calculation by utilizing the CRS reference signal in the second sampling signal to obtain the actual delay position of the CRS in the second sampling signal so as to obtain the actual delay position of the CRS transmitted by each antenna port in the physical cell.
According to a fourth aspect, there is provided in an embodiment a user equipment comprising:
the sampling unit is used for receiving the LTE signal sent by the base station to be detected, and intercepting a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length;
the CRS ideal delay position acquisition unit is used for searching the PSS in the first sampling signal and calculating the delay position of the frame head of the wireless signal frame in the first sampling signal according to the delay position of the searched PSS in the first sampling signal; determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal;
a CRS reference signal acquisition unit, configured to search an SSS sequence in the first sampling signal according to a delay position of the SSS specified by a preset protocol, and determine a physical cell identifier corresponding to the base station to be detected according to the searched PSS sequence and SSS sequence; according to the physical cell identification, a CRS reference signal is obtained;
the intercepting unit is used for selecting a positioning time slot from the first sampling signal according to the ideal delay position of the CRS, wherein the positioning time slot at least comprises the ideal delay position of the CRS; intercepting a signal with a second time length in the positioning time slot by taking an ideal delay position of the CRS as a center to serve as a second sampling signal;
the search unit is used for carrying out correlation calculation based on a frequency domain by utilizing the CRS reference signal in the second sampling signal to obtain an actual delay position of the CRS in the second sampling signal so as to obtain the actual delay position of the CRS transmitted by each antenna port in the physical cell;
and the time alignment error measurement unit is used for determining the time alignment error between the antenna ports and the base station to be measured according to the actual delay positions of the CRSs transmitted by the antenna ports.
According to the CRS searching method, the LTE time alignment error determining method and the user equipment of the foregoing embodiments, the CRS searching method performs correlation computation on the generated CRS reference signal and the second sampling signal by using a fast fourier recursive algorithm in a frequency domain, so as to search an actual delay position of the CRS in the second sampling signal, so as to obtain the actual delay position of the CRS transmitted by each antenna port in the physical cell, so that interference of other downlink signals transmitted on subcarriers unused by the CRS on a correlation computation result during time domain correlation computation can be avoided, the CRS can be searched more accurately, and occupied operation resources are less.
Drawings
Fig. 1 is a flowchart of an LTE-based CRS search method of an embodiment;
fig. 2 is a flowchart of an LTE time alignment error measurement method according to an embodiment;
fig. 3 is a schematic structural diagram of a user equipment according to an embodiment;
fig. 4 is a schematic structural diagram of a user equipment according to another embodiment.
Detailed Description
The present application is described in further detail below with reference to the accompanying drawings by way of specific embodiments. Wherein like elements in different embodiments are numbered alike in association. In the following embodiments, numerous specific details are set forth in order to provide a better understanding of the present application. However, one skilled in the art will readily recognize that some of the features may be omitted, or replaced by other elements, materials, or methods in different situations. In some instances, some operations associated with the present application have not been shown or described in the specification to avoid obscuring the core portions of the present application, and may not be necessary for a person skilled in the art to describe in detail the relevant operations based on the description herein and the general knowledge of one skilled in the art.
Furthermore, the described features, operations, or characteristics of the description may be combined in any suitable manner in various embodiments. Also, various steps or acts in the method descriptions may be interchanged or modified in a manner apparent to those of ordinary skill in the art. Thus, the various orders in the description and drawings are for clarity of description of only certain embodiments, and are not meant to be required orders unless otherwise indicated.
The numbering of the components itself, e.g. "first", "second", etc., is used herein merely to distinguish between the described objects and does not have any sequential or technical meaning. The terms "coupled" and "connected," as used herein, are intended to encompass both direct and indirect coupling (coupling), unless otherwise indicated.
In the embodiment of the application, CRS related search is performed in a frequency domain to extract signal data on subcarriers occupied by CRS and eliminate signal interference on other subcarriers; in addition, compared with the conventional frequency domain fast Fourier transform, the method adopts a recursive algorithm of the fast Fourier transform to perform correlation search on the CRS, so that occupied operation resources are reduced.
The following is a description of the english abbreviations referred to in this application.
LTE (long term evolution) long term evolution;
CRS (cell-specific reference signal) represents a cell-specific reference signal;
PSS (primary synchronization signal) the primary synchronization signal;
SSS (secondary synchronization signal) the secondary synchronization signal;
PCI (physical cell identifier) the physical cell identity.
Referring to fig. 1, an embodiment of the present application provides a CRS search method based on LTE, hereinafter referred to as CRS search method, and the CRS search method may include steps 101 to 105, which are described in detail below.
Step 101: receiving an LTE signal sent by a base station to be detected, and intercepting a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length.
The structure of the time domain resource of the LTE channel is specified according to the section 4 of the protocol 3GPP TS 36.211, the channel resource is divided according to the form of wireless signal frames, and each wireless signal frame occupies 10ms fixedly. In addition, section 4 of the protocol 3gpp TS 36.213 specifies that the user equipment performs physical cell search based on the synchronization signal, and section 3GPP TS 36.211 6.11 specifies that PSS and SSS are transmitted on fixed time-frequency domain resources within the radio signal frame.
In this embodiment, in order to determine the position of the start time of the wireless signal frame in the received LTE signal, after sampling the LTE signal received by the receiving antenna according to the sampling rate specified by the protocol, signal data of at least one wireless signal frame time length is intercepted as the first sampling signal, so as to ensure that PSS and SSS can be searched in the subsequent analysis. In a preferred embodiment, in order to reduce the computation amount during PSS searching as much as possible, the present embodiment intercepts only one or two signals of the radio signal frame length as the first sampling signal.
Step 102: searching PSS in the first sampling signal, and calculating the delay position of the frame head of the wireless signal frame in the first sampling signal according to the delay position of the searched PSS in the first sampling signal; and determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal. In some embodiments, the frame header of the wireless signal frame may be a start time of the wireless signal frame, and the delay position of the frame header of the wireless signal frame in the first sampling signal is calculated, that is, the delay position of the start time of the wireless signal frame in the first sampling signal is calculated.
Step 103: searching an SSS sequence in a first sampling signal according to a delay position of the SSS specified by a preset protocol, and determining a physical cell identifier corresponding to a base station to be detected according to the searched PSS sequence and the SSS sequence; and acquiring the CRS reference signal according to the physical cell identification. The preset protocol is protocol 3GPP TS 36.211 6.11.
According to the protocol 3GPP TS 36.211 6.11 section, the base station should transmit PSS and SSS at fixed time-frequency domain positions every half of the radio signal frame. The PSS sequence transmitted in the first half frame and the second half frame in the same radio signal frame are identical, and the SSS sequence is different. The PSS sequence transmitted by the base station is determined by the Physical Cell Identity (PCI), while the SSS sequence is determined by the PCI and the field position in which it is located.
Since the PSS and the SSS use only 62 subcarriers in the center of the transmission bandwidth for transmission, when searching for the synchronization signals (PSS and SSS), in order to avoid interference of other channels, filtering operation needs to be performed on the data intercepted by the wireless signal frame in advance, and other signals except for the subcarriers are used for filtering the synchronization signals.
When the user equipment does not know the PCI in advance, the PCI needs to be judged according to the PSS and SSS search results. Protocol 3GPP TS 36.211 6.11 section specifies PCI value ranges of [0, 503 ]]The physical cell identification range is divided into 168 groupsIs [0, 167 ]]Each group ofInner sign->In the range of [0,2]The physical cell identity may be expressed as:
；
according to protocol 3GPP TS 36.211 6.11 section, the PSS sequence is defined only byThree possible PSS sequences are determined to exist. The receiving system maps the PSS sequence to the transmission bandwidth center according to the PSS channel mapping mode specified by the protocol, and generates the PSS reference time domain signal through OFDM modulation.
The PSS is then searched for in the truncated first sampled signal by means of time-domain correlation. The receiving system takes signal data with the length of at least 20ms (default SSB broadcast period) from the first sampling signal after synchronous filtering asIts length is marked as->The PSS reference time domain signal is denoted +.>The length of the OFDM signal is the length of the OFDM symbol corresponding to the sampling rate of the first sampling signalNDelay timedPSS correlation coefficient of each sampling period is shown in the following expression, wherein +.>Represents->Is conjugated with:
；
deriving correlation coefficients for reference signals generated for each PSS sequenceDelay value of maximum value>If the correlation coefficient->And if the PSS sequence is larger than the preset correlation coefficient threshold value, judging that the corresponding PSS sequence is searched. Judging +.>Delay position with PSS->。
In order to improve the operation efficiency of the PSS search, it is generally considered to downsample the truncated data for the PSS search with the PSS reference time domain, so as to reduce the operation amount of the PSS search.
Under the pre-specified duplex mode condition, according to the time domain position of PSS within half frame specified by protocol, the PSS delay position is used for delayingThe field start time may be located. However, since PSS is transmitted at the same position in the front half frame and the rear half frame and the PSS sequence is transmitted in the same position, it is temporarily impossible to determine whether the located half frame start position is the radio signal frame start position.
PSS delay positionThe marked PSS is located in the first half frame or the second half frame, and needs to be determined by SSS search. After PSS search has been determined->Based on +.>Uncertainty, unknown to the front and back half frames, of SSS sequence presence 336Potentially, 336 SSS reference time domain signals may be generated for SSS search in a PSS-like method.
In a pre-designated duplex mode, according to protocol regulation, the relative delay position of SSS and PSS in a field frame is a fixed value, so that sampling data with a certain length can be intercepted from sampling data after synchronous filtering by taking the calculated SSS delay position as a center, and SSS related searching is carried out by a PSS searching similar method.
Since the protocol specifies that the time domain position of the SSS in the wireless signal frame always leads the PSS, when the SSS sampling data is intercepted, the calculated delay position may be less than 0 and extend forward beyond the sampling start point; in this case, the synchronization signal is periodically transmitted at a fixed time domain position in the radio signal frame, and it is considered that the excess portion is searched forward from the end of the sampling data for SSS time domain positions. The precondition for performing the above operation is that the truncated data length is an integer multiple of the wireless signal frame length.
Based on the SSS sequence with maximum correlation coefficient value obtained during SSS search, determiningAnd the half frame position of the synchronous signal; whereby the search for PSS is combined>Delay position with PSS->Further calculating the number of the physical cell and the starting time of the wireless signal frame.
Step 104: selecting a positioning time slot from the first sampling signal according to the ideal delay position of the CRS, wherein the positioning time slot at least comprises the ideal delay position of the CRS; and intercepting a signal with a second time length in the positioning time slot by taking the ideal delay position of the CRS as a second sampling signal.
According to protocol 3GPP TS 36.211 6.10.1.2 section, CRS is transmitted by antenna ports 0,1 on OFDM symbol 0 of the positioning slot, while CRS is transmitted by antenna ports 2,3 on OFDM symbol 1 of the slot; therefore, after the positioning time slot of the CRS is selected, only two OFDM symbols in the positioning time slot are needed to be used as centers, and a signal with a certain length is intercepted from the first sampling signal to be used as a second sampling signal for subsequent analysis.
It should be noted that, the radio signal frame may be equally divided into 10 subframes, and may include an uplink subframe, a special subframe, and a downlink subframe, where the special subframe may further include a downlink pilot, a guard interval, and an uplink pilot, where CRS may be transmitted only in the downlink pilot and the downlink subframe of the special subframe. Thus, in some embodiments, a positioning slot may be selected from a downlink subframe of a radio signal frame in the first sampled signal.
Step 105: and in the second sampling signal, performing correlation calculation based on a frequency domain by using the CRS reference signal to obtain an actual delay position of the CRS in the second sampling signal so as to obtain the actual delay position of the CRS transmitted by each antenna port in the physical cell.
Generating a corresponding CRS sequence according to a protocol 3GPP TS 36.211 6.10.1.1 section according to a physical cell obtained by searching the synchronous signal, the number of the positioning time slot selected in the step 104 in a wireless signal frame and a preset LTE signal cyclic prefix type; and then generating CRS reference signals for the antenna ports 0,1,2 and 3 according to a CRS subcarrier mapping mode of each antenna port specified in a protocol 3GPP TS 36.211 6.10.1.2 section.
In order to avoid repeated operations except for FFT (fast fourier transform) during OFDM demodulation in the subsequent CRS search, algorithm efficiency is further improved, the CRS reference signal may be processed into a form obtained by OFDM time domain sampling signal FFT, so as to process the obtained sequence as a CRS reference sequence. According to the protocol 3GPP TS 36.211 6.12 section, the specific implementation method of the treatment is as follows: zero data is filled at two sides of the CRS reference signal, so that the length of the CRS reference signal reaches the FFT point number; and then performs an FFT-Shift operation that skips the zero frequency point.
In the case where the sampling rate of the second sampled signal is limited by the ADC sampling rate of the receiving device, it is generally considered to perform appropriate up-sampling of the second sampled signal to obtain higher measurement accuracy. In the case of up-sampling, the FFT point number of the above-described reference sequence processing flow should be set to the FFT point number at the up-sampled signal sampling rate.
According to the protocol, locating the 0 th OFDM symbol of the time slot 0 as the center, and searching CRS reference signals transmitted by antenna ports 0 and 1 in intercepted data with a certain length respectively; similarly, the CRS reference signals transmitted by the antenna ports 2,3 are searched for in the truncated data centered on the 1 st OFDM symbol of the positioning slot 0, respectively.
In some embodiments, a fast fourier recursive algorithm is adopted to perform correlation calculation on the second sampling signal and each position of the CRS reference signal transmitted by each antenna port in a second time length, so as to obtain a correlation coefficient of each position;
and performing correlation calculation on the second sampling signal and each position of the CRS reference signal transmitted by each antenna port in a second time length by adopting a fast Fourier recursive algorithm to obtain a correlation coefficient of each position, wherein the method comprises the following steps:
the correlation coefficient of the d-th position is obtained according to the following expression:
；
wherein,subcarrier data representing the conversion of the second sampled signal into the frequency domain, k representing subcarrier number, d representing delay position, +.>，/>Representing a difference between a time length of the second sampling signal and a time length of the CRS reference signal; />Representing antenna portspCorresponding CRS reference signals;
wherein,the recurrence is derived from the following expression:
；
wherein the initial valueBy->Execution->Point fast Fourier transform derived, < >>Representing time delaydSecond sample signal of point,/>M is the length of CRS reference signal, +.>Representing the time delay [ ]M+d) A second sampled signal of the point.
And taking the position corresponding to the maximum value of the correlation coefficient corresponding to each position as the actual delay position of the CRS in the second sampling signal. In this embodiment, if the maximum value of the correlation coefficient is greater than the preset correlation coefficient threshold, it is determined that the CRS transmitted by the received antenna port is a valid CRS.
Thus, after determining the actual delay position of the CRS in the second sampling signal, CRS searching is completed.
Referring to fig. 2, the embodiment of the present application further provides an LTE time alignment error measurement method, which may include steps 201 to 206, and is described in detail below.
Step 201: receiving an LTE signal sent by a base station to be detected, and intercepting a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length.
Step 202: searching PSS in the first sampling signal, and calculating the delay position of the frame head of the wireless signal frame in the first sampling signal according to the delay position of the searched PSS in the first sampling signal; and determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal.
Step 203: searching an SSS sequence in a first sampling signal according to a delay position of the SSS specified by a preset protocol, and determining a physical cell identifier corresponding to a base station to be detected according to the searched PSS sequence and the SSS sequence; according to the physical cell identification, a CRS reference signal is obtained; the preset protocol is a protocol 3GPP TS 36.213.
Step 204: selecting a positioning time slot from the first sampling signal according to the ideal delay position of the CRS, wherein the positioning time slot at least comprises the ideal delay position of the CRS; and intercepting a signal with a second time length in the positioning time slot by taking the ideal delay position of the CRS as a second sampling signal.
Step 205: and in the second sampling signal, performing correlation calculation based on a frequency domain by using the CRS reference signal to obtain an actual delay position of the CRS in the second sampling signal so as to obtain the actual delay position of the CRS transmitted by each antenna port in the physical cell.
Step 206: and determining the time alignment error between the CRS and the base station to be tested according to the actual delay position of the CRS transmitted by each antenna port. In this embodiment, the maximum value of the two-by-two differences of the actual delay positions of CRSs transmitted by each antenna port is used as a time alignment error to evaluate the base station to be tested.
It should be noted that, the method steps of steps 201 to 205 in the embodiments of the present application are the same as those of the above embodiments, and the specific implementation manner of the method steps is described in detail in the above embodiments, which is not repeated here.
Referring to fig. 3, the present application further provides a user equipment, where the user equipment includes: sampling unit 301, CRS ideal delay position acquisition unit 302, CRS reference signal acquisition unit 303, clipping unit 304, and searching unit 305.
The sampling unit 301 is configured to receive an LTE signal sent by a base station to be tested, and intercept a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length.
The CRS ideal delay position obtaining unit 302 is configured to search for a PSS in the first sampled signal, and calculate a delay position of a frame header of the wireless signal frame in the first sampled signal according to the delay position of the searched PSS in the first sampled signal; and determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal.
The CRS reference signal obtaining unit 303 is configured to search for an SSS sequence in the first sampling signal according to a delay position of the SSS specified by a preset protocol, and determine a physical cell identifier corresponding to the base station to be detected according to the searched PSS sequence and SSS sequence; and acquiring the CRS reference signal according to the physical cell identification.
The interception unit 304 is configured to select a time slot from the first sampling signal according to an ideal delay position of the CRS, where the time slot at least includes the ideal delay position of the CRS; and intercepting a signal with a second time length in the time slot by taking the ideal delay position of the CRS as a second sampling signal.
The searching unit 305 is configured to perform correlation calculation based on a frequency domain by using a CRS reference signal in the second sampling signal, so as to obtain an actual delay position of the CRS transmitted by each antenna port in the physical cell.
Based on the above-mentioned ue, please refer to fig. 4, the ue further includes a time alignment error measurement unit 306 on the basis of the one shown in fig. 3, where the time alignment error measurement unit 306 is configured to determine a time alignment error with the base station to be tested according to the actual delay positions of CRSs transmitted by the antenna ports.
It should be noted that each functional unit of the user equipment corresponds to a method step in the above embodiment, and a description thereof will not be repeated here.
The foregoing description of specific examples has been presented only to aid in the understanding of the present application and is not intended to limit the present application. Several simple deductions, modifications or substitutions may also be made by the person skilled in the art to which the present application pertains, according to the idea of the present application.
Claims (10)
1. A CRS search method based on LTE, comprising:
receiving an LTE signal sent by a base station to be detected, and intercepting a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length;
searching PSS in the first sampling signal, and calculating the delay position of the frame head of the wireless signal frame in the first sampling signal according to the delay position of the searched PSS in the first sampling signal; determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal;
searching an SSS sequence in the first sampling signal according to a delay position of the SSS specified by a preset protocol, and determining a physical cell identifier corresponding to the base station to be detected according to the searched PSS sequence and the SSS sequence; according to the physical cell identification, a CRS reference signal is obtained;
selecting a positioning time slot from the first sampling signal according to the ideal delay position of the CRS, wherein the positioning time slot at least comprises the ideal delay position of the CRS; intercepting a signal with a second time length in the positioning time slot by taking an ideal delay position of the CRS as a center to serve as a second sampling signal;
and in the second sampling signal, performing correlation calculation based on a frequency domain by using the CRS reference signal to obtain an actual delay position of the CRS in the second sampling signal so as to obtain the actual delay position of the CRS transmitted by each antenna port in the physical cell corresponding to the base station to be detected.
2. An LTE time alignment error measurement method, comprising:
receiving an LTE signal sent by a base station to be detected, and intercepting a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length;
searching PSS in the first sampling signal, and calculating the delay position of the frame head of the wireless signal frame in the first sampling signal according to the delay position of the searched PSS in the first sampling signal; determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal;
searching an SSS sequence in the first sampling signal according to a delay position of the SSS specified by a preset protocol, and determining a physical cell identifier corresponding to the base station to be detected according to the searched PSS sequence and the SSS sequence; according to the physical cell identification, a CRS reference signal is obtained;
selecting a positioning time slot from the first sampling signal according to the ideal delay position of the CRS, wherein the positioning time slot at least comprises the ideal delay position of the CRS; intercepting a signal with a second time length in the positioning time slot by taking an ideal delay position of the CRS as a center to serve as a second sampling signal;
in the second sampling signal, performing correlation calculation based on a frequency domain by using the CRS reference signal to obtain an actual delay position of a CRS in the second sampling signal so as to obtain the actual delay position of the CRS transmitted by each antenna port in a physical cell corresponding to the base station to be detected;
and determining the time alignment error of the base station to be detected according to the actual delay positions of CRSs transmitted by the antenna ports.
3. The method of claim 2, wherein determining the time alignment error of the base station under test based on the actual delay positions of CRSs transmitted by the respective antenna ports comprises:
and taking the maximum value of any two difference values in the actual delay positions of CRS transmitted by each antenna port as the time alignment error of the base station to be tested.
4. The method of claim 1 or 2, wherein determining the ideal delay position of the CRS based on the delay position of the frame header of the radio signal frame in the first sampled signal comprises:
and determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal and the time domain position of the CRS in the wireless signal frame, which is specified by a preset protocol.
5. The method of claim 1 or 2, wherein the performing frequency domain based correlation calculation in the second sampled signal using the CRS reference signal to obtain an actual delay position of CRS in the second sampled signal includes:
performing correlation calculation on each position point of the second sampling signal and the CRS reference signal in a second time length by adopting a fast Fourier recursive algorithm to obtain a correlation coefficient of each position point;
and taking the position point corresponding to the maximum value of the correlation coefficient corresponding to each position point as the actual delay position of the CRS in the second sampling signal.
6. The method of claim 5, wherein performing correlation calculations for each location of the second sampled signal and the CRS reference signal over a second length of time using a fast fourier recursive algorithm to obtain correlation coefficients for each location, comprising:
the correlation coefficient of the d-th position is obtained according to the following expression:
；
wherein,subcarrier data representing the conversion of the second sampled signal into the frequency domain, k representing subcarrier number, d representing delay position, +.>，/>Representing a difference between a time length of the second sampling signal and a time length of the CRS reference signal; />Representing antenna portspCorresponding CRS reference signals; />Representation->Conjugation of (2);
wherein,the recurrence is derived from the following expression:
；
wherein the initial valueBy->Execution->Point fast Fourier transform derived, < >>Representing time delaydSecond sample signal of point,/>M is the length of CRS reference signal, +.>Representing the time delay [ ]M+d) A second sampled signal of the point.
7. The method as recited in claim 5, further comprising:
and if the maximum value of the correlation coefficient is larger than a preset correlation coefficient threshold value, judging that the received CRS transmitted by the antenna port is a valid CRS.
8. A user device, comprising:
the sampling unit is used for receiving the LTE signal sent by the base station to be detected, and intercepting a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length;
the CRS ideal delay position acquisition unit is used for searching the PSS in the first sampling signal and calculating the delay position of the frame head of the wireless signal frame in the first sampling signal according to the delay position of the searched PSS in the first sampling signal; determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal;
a CRS reference signal acquisition unit, configured to search an SSS sequence in the first sampling signal according to a delay position of the SSS specified by a preset protocol, and determine a physical cell identifier corresponding to the base station to be detected according to the searched PSS sequence and SSS sequence; according to the physical cell identification, a CRS reference signal is obtained;
the intercepting unit is used for selecting a positioning time slot from the first sampling signal according to the ideal delay position of the CRS, wherein the positioning time slot at least comprises the ideal delay position of the CRS; intercepting a signal with a second time length in the positioning time slot by taking an ideal delay position of the CRS as a center to serve as a second sampling signal;
and the searching unit is used for carrying out frequency domain-based correlation calculation by utilizing the CRS reference signal in the second sampling signal to obtain the actual delay position of the CRS in the second sampling signal so as to obtain the actual delay position of the CRS transmitted by each antenna port in the physical cell corresponding to the base station to be detected.
9. A user device, comprising:
the sampling unit is used for receiving the LTE signal sent by the base station to be detected, and intercepting a signal with a first time length from the received LTE signal as a first sampling signal; wherein the first time length includes at least one wireless signal frame length;
the CRS ideal delay position acquisition unit is used for searching the PSS in the first sampling signal and calculating the delay position of the frame head of the wireless signal frame in the first sampling signal according to the delay position of the searched PSS in the first sampling signal; determining an ideal delay position of the CRS according to the delay position of the frame head of the wireless signal frame in the first sampling signal;
a CRS reference signal acquisition unit, configured to search an SSS sequence in the first sampling signal according to a delay position of the SSS specified by a preset protocol, and determine a physical cell identifier corresponding to the base station to be detected according to the searched PSS sequence and SSS sequence; according to the physical cell identification, a CRS reference signal is obtained;
the intercepting unit is used for selecting a positioning time slot from the first sampling signal according to the ideal delay position of the CRS, wherein the positioning time slot at least comprises the ideal delay position of the CRS; intercepting a signal with a second time length in the positioning time slot by taking an ideal delay position of the CRS as a center to serve as a second sampling signal;
the search unit is used for carrying out correlation calculation based on a frequency domain by utilizing the CRS reference signal in the second sampling signal to obtain an actual delay position of the CRS in the second sampling signal so as to obtain the actual delay position of the CRS transmitted by each antenna port in the physical cell corresponding to the base station to be detected;
and the time alignment error measurement unit is used for determining the time alignment error between the antenna ports and the base station to be measured according to the actual delay positions of the CRSs transmitted by the antenna ports.
10. The ue of claim 8 or 9, wherein the performing, in the second sampled signal, correlation calculation based on a frequency domain using the CRS reference signal to obtain an actual delay position of the CRS in the second sampled signal includes:
performing correlation calculation on the second sampling signal and each position point of the CRS reference sequence transmitted by each antenna port in a second time length by adopting a fast Fourier recursive algorithm to obtain a correlation coefficient of each position point;
taking the position point corresponding to the maximum value of the correlation coefficient corresponding to each position point as the actual delay position of the CRS in the second sampling signal;
and performing correlation calculation on the second sampling signal and each position point of the CRS reference signal transmitted by each antenna port in a second time length by adopting a fast Fourier recursive algorithm to obtain a correlation coefficient of each position point, wherein the method comprises the following steps:
the correlation coefficient of the d-th position is obtained according to the following expression:
；
wherein,subcarrier data representing the conversion of the second sampled signal into the frequency domain, k representing subcarrier number, d representing delay position, +.>，/>Representing a difference between a time length of the second sampling signal and a time length of the CRS reference signal; />Representing antenna portspCorresponding CRS reference signals; />Representation->Conjugation of (2);
wherein,the recurrence is derived from the following expression:
；
wherein the initial valueBy->Execution->Point fast Fourier transform derived, < >>Representing time delaydSecond sample signal of point,/>M is the length of CRS reference signal, +.>Representing the time delay [ ]M+d) A second sampled signal of the point.
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| CN113840327A (en) * | 2021-10-09 | 2021-12-24 | 杰创智能科技股份有限公司 | LTE control channel resource mapping method and device |
| CN114374589A (en) * | 2022-01-11 | 2022-04-19 | 深圳凡维泰科技服务有限公司 | PSS cross-correlation algorithm of 5G-NR system based on FPGA |
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| CN113840327A (en) * | 2021-10-09 | 2021-12-24 | 杰创智能科技股份有限公司 | LTE control channel resource mapping method and device |
| CN114374589A (en) * | 2022-01-11 | 2022-04-19 | 深圳凡维泰科技服务有限公司 | PSS cross-correlation algorithm of 5G-NR system based on FPGA |
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