CN102711242A - Method for measuring time of arrival of reference signal of position neighbor cell, and terminal - Google Patents

Abstract

The present invention provides a method and terminal for measuring and positioning the arrival time of a neighbor cell reference signal. The method includes: receiving an auxiliary message for measuring the observed time difference of arrival. The message includes positioning reference cell information and positioning neighbor cell information. A signal containing a positioning reference signal for positioning a neighboring cell within a measurement opportunity is received. According to the observed time difference of arrival measurement assistance message, it is judged whether the positioning reference cell is the serving cell, and whether it is within the measurement opportunity of the same frequency layer as the positioning neighbor cell. If yes, it is judged whether the interference start condition is satisfied. If it is satisfied, the frequency domain interference cancellation processing or the time domain interference cancellation processing based on the local positioning reference signal is started for the received signal; otherwise, the non-interference cancellation processing is started. The measurement method provided by the invention eliminates the interference of the serving cell to the reference signal of the positioning neighbor cell, and then measures the arrival time of the reference signal of the positioning neighbor cell, thereby realizing the positioning of the terminal.

Description

Method and terminal for measuring and positioning neighbor cell reference signal arrival time

technical field

The invention relates to the technical field of wireless communication, and in particular to a method and a terminal for measuring and positioning the arrival time of reference signals of neighbor cells.

Background technique

Long Term Evolution (LTE) version 9 (release 9, R9) proposes to transmit Position Reference Single (PRS) to realize Observation Time Difference of Arrival (OTDOA) positioning technology.

OTDOA positioning technology is a positioning method based on UE-assisted. During the positioning process, the position of the terminal (User Equipment, referred to as UE) requires the UE to perform assisted reference signal time difference (Reference Signal Time Different, hereinafter referred to as RSTD) measurement. The side estimates the position of the UE according to the RSTD result measured by the UE. Specifically, the existing OTDOA positioning technology includes the following steps:

1) The UE or any device in the network sends a positioning request to the network side;

2) The network side determines the positioning to start OTDOA according to the positioning request and the UE's capabilities or positioning service quality (Quality of Service, QoS) requirements;

3) The network side sends an OTDOA positioning request and a positioning assistance message to the UE. For the definition of the positioning assistance message, see 3GPP TS 36.3556.5.1.2;

4) After receiving the positioning assistance message, the UE performs RSTD measurement and reports it to the network side;

5) The network side locates the UE according to the RSTD measurement result reported by the UE.

The downlink subframe sent by the base station carries the PRS, and the UE needs to detect the PRS arrival time delivered by at least three base stations, and obtain the PRS arrival time difference between the base station that locates the neighbor cell and the base station that locates the reference cell.

Wherein, the method for obtaining the interference-free cancellation of the positioning reference signal arrival time difference of a cell includes the following steps:

1) Receive a mixed signal of positioning reference signals of multiple base stations in one measurement opportunity in one frequency layer, where the mixed signal is a received signal containing the positioning reference signal of the cell.

2) The UE generates the local sequence of the positioning reference signal of the cell according to the PRS information of the cell in the positioning assistance message, and the specific method is defined in 3GPP TS 36.2116.10.4;

3) Correlate the local sequence with the received signal to obtain the correlation value in the corresponding symbol,

4) Repeat steps 2), 3) to obtain the correlation value in one subframe and the correlation values in multiple subframes;

5) According to the correlation values in multiple subframes, the arrival time of the reference signal of the positioning neighbor cell is obtained.

In the above process, since the signal containing the PRS subframe received by the terminal is a mixed signal of the PRS signal of the serving base station and the neighboring base station, when the terminal is in the central area of the serving cell, the received signal of the neighboring cell will be affected by the signal of the serving cell. strong interference. If the interference is too large, the measured PRS arrival time of the neighbor cell will be wrong, which will affect the final positioning accuracy.

Contents of the invention

An embodiment of the present invention provides a method for measuring the time of arrival of a neighbor cell reference signal, which eliminates the interference of the serving cell's positioning reference signal to the positioning neighbor cell's positioning reference signal in the OTDOA positioning technology, and then accurately obtains the location of the neighbor cell reference signal. Arrival time to achieve precise positioning of the terminal.

Specifically, the method for measuring and positioning neighbor cell reference signal arrival time provided by the embodiment of the present invention includes the following steps:

receiving an observed time difference of arrival measurement assistance message, where the observed time difference of arrival measurement assistance message includes positioning reference cell information and positioning neighbor cell information;

According to the observed time difference of arrival measurement assistance message, receive a signal containing the positioning reference signal PRS of the positioning neighbor cell in one measurement opportunity;

According to the observed time difference of arrival measurement assistance message, determine whether the positioning reference cell is a serving cell, and whether the positioning reference cell and the positioning neighbor cell are within the one measurement opportunity of a frequency layer;

If the positioning reference cell is the serving cell and the positioning reference cell and the positioning neighbor cell are within the one measurement opportunity of the frequency layer, then further judge whether the interference cancellation activation condition is satisfied, if the interference elimination activation condition is satisfied , then start frequency-domain interference cancellation processing based on local positioning reference signal or time-domain interference cancellation processing based on local positioning reference signal on the received signal; otherwise, start non-interference cancellation processing.

In addition, the embodiment of the present invention also provides a terminal for measuring and positioning the arrival time of reference signals of neighbor cells, the terminal includes:

The obtaining unit is used to obtain the observed time difference of arrival measurement auxiliary message, the observed time difference of arrival measurement auxiliary message includes positioning reference cell information and positioning neighbor cell information, and the obtaining unit is also used to receive a measurement opportunity containing positioning neighbor cell information a signal of a positioning reference signal;

A judging unit, configured to judge whether the positioning reference cell is a serving cell, and whether the positioning reference cell and the positioning neighbor cell are within the one measurement opportunity of a frequency layer;

If the positioning reference cell is a serving cell and the positioning reference cell and the positioning neighbor cell are within the one measurement opportunity of the frequency layer, the judging unit further judges the start condition of interference cancellation; if satisfied, Then start frequency-domain interference cancellation processing based on local positioning reference signal or time-domain interference cancellation processing based on local positioning reference signal on the received signal; if not, start non-interference cancellation processing;

The interference elimination unit is configured to perform frequency domain interference elimination processing based on the local positioning reference signal or time domain interference elimination processing or non-interference elimination processing based on the local positioning reference signal on the received signal.

The method and terminal for measuring and positioning neighbor cell reference signal arrival time provided by the embodiments of the present invention judge whether the positioning reference cell is a serving cell according to the observed time difference of arrival measurement auxiliary information issued by the high layer, and judge according to the observed time difference of arrival measurement auxiliary message Whether the PRS of the serving cell and the PRS of the positioning neighbor cell are in the same measurement opportunity (occasion), and then further judge whether the UE meets the interference cancellation start condition, and finally start the frequency domain based on the local positioning reference signal for the received signal according to the judgment result Interference elimination processing or time-domain interference elimination processing based on local positioning reference signals, in order to eliminate the interference of positioning reference signals of serving cells on positioning reference signals of neighboring cells in OTDOA positioning technology, and then accurately obtain the arrival time of positioning reference signals of neighboring cells .

Description of drawings

FIG. 1 is a flowchart of a method for measuring and locating the time of arrival of reference signals of neighbor cells according to Embodiment 1 of the present invention;

2 is a flow chart of a method for measuring and positioning neighbor cell reference signal arrival times based on frequency domain interference cancellation of local positioning reference signals according to Embodiment 2 of the present invention;

FIG. 3 is a schematic diagram of measuring and positioning neighbor cell reference signal arrival time based on frequency domain interference cancellation of local positioning reference signal;

4 is a flow chart of a method for measuring and positioning neighbor cell reference signal arrival time based on time-domain interference cancellation of local positioning reference signals according to Embodiment 3 of the present invention;

Fig. 5 is a schematic diagram of time-domain interference cancellation measurement and positioning neighbor cell reference signal arrival time based on local positioning reference signal;

FIG. 6 is a schematic diagram of a terminal for measuring and positioning the arrival time of a neighbor cell reference signal according to Embodiment 1 of the present invention;

FIG. 7 is a schematic diagram of a terminal for measuring and positioning neighbor cell reference signal arrival time that satisfies frequency domain interference cancellation according to Embodiment 2 of the present invention;

FIG. 8 is a schematic diagram of a terminal for measuring and positioning neighbor cell reference signal arrival time that satisfies time-domain interference cancellation according to Embodiment 3 of the present invention;

FIG. 9 is a schematic diagram of another terminal for measuring and positioning the arrival time of reference signals of neighbor cells according to the present invention.

Detailed ways

The embodiment of the present invention provides a method for obtaining the PRS arrival time of the neighbor cell based on the interference elimination of the local positioning reference signal, and improves the SINR (Signal to Interference and Noise Ratio) in the measurement sample, so as to locate the neighbor in the serving cell When there is a large interference in the cell, the accuracy of measuring the PRS arrival time of the neighbor cell is improved, so as to achieve the purpose of improving the positioning accuracy.

Fig. 1 is the flow chart of the method for measuring and positioning neighbor cell reference signal arrival time in Embodiment 1 of the present invention, as shown in Fig. 1, the method for interference elimination in this positioning system includes:

Step S101: Receive the observed time difference of arrival measurement auxiliary message, and according to the observed time difference of arrival measurement auxiliary message, receive a received signal containing the positioning reference signal of the positioning neighbor cell within a measurement opportunity.

In this step, the UE obtains the observed time difference of arrival (OTDOA) measurement auxiliary information issued by the upper layer. The observed time difference of arrival measurement auxiliary information includes positioning reference cell information and positioning neighbor cell information. For details, see 3GPP TS 36.3556.5.1.2.

Obtain the configuration of the measurement opportunity according to receiving the observed time difference of arrival measurement auxiliary message, such as frequency layer, period, starting subframe number and other parameters, where the frequency layer is a frequency point, and the same frequency layer means the same frequency; in addition, the UE also Receive the received signal containing the positioning reference signal of the positioning neighbor cell in one measurement opportunity, and each measurement opportunity includes multiple downlink subframes including PRS signals, such as 1 to 6 downlink subframes.

Step S102: According to the observed time difference of arrival measurement assistance message, determine whether the positioning reference cell is the serving cell, and whether it is in the measurement opportunity of the same frequency layer as the positioning neighbor cell.

In this step, the UE compares the physCellID, cellGlodballd, and earfcn fields in the positioning reference cell information to determine whether the positioning reference cell is a serving cell. According to earfcn and prs-mutingInfo in the location reference cell information and the location neighbor cell information, judge whether the location reference cell is a measurement opportunity (Occasion) in the same frequency layer as the location neighbor cell; if so, then execute step S103; otherwise , execute S105.

Step S103: It is further judged whether the starting condition of interference cancellation is satisfied.

In this step, the UE judges whether the interference based on the local positioning reference signal is satisfied according to the relationship between the PRS bandwidth of the serving cell and the PRS bandwidth of the neighbor cell or the relationship between the number of PRS downlink subframes of the serving cell and the number of PRS downlink subframes of the neighbor cell. If the starting condition of cancellation is yes, execute step S104; otherwise, consider that the interference cancellation condition based on the local positioning reference signal is not met, and execute S105 without interference cancellation.

Step S104: Start the frequency-domain interference cancellation process based on the local positioning reference signal or the time-domain interference cancellation process based on the local positioning reference signal.

In this step, according to the relationship between the PRS bandwidth of the serving cell and the PRS bandwidth of the positioning neighbor cell judged in step S103, the UE starts the frequency domain interference cancellation based on the local positioning reference signal for the received signal, so as to eliminate the influence of the serving cell on the positioning neighbor. The interference of the positioning reference signal of the cell; or, according to the relationship between the number of PRS downlink subframes of the serving cell and the number of PRS downlink subframes of the positioning neighbor cell judged in step S103, the time domain interference based on the local positioning reference signal is started for the received signal Eliminate processing.

Step S105, performing non-interference cancellation processing.

Specifically, the non-interference cancellation method is as follows: UE generates the local sequence of the positioning reference signal of the neighboring cell according to the PRS signal of the positioning neighbor cell in the observed time difference of arrival measurement assistance message; correlates the local sequence with the received signal, and obtains the corresponding Correlation value within a symbol, that is, to correlate the symbol of the local sequence with the symbol corresponding to the symbol in the received signal to obtain the correlation value of the symbol; repeat execution to obtain the correlation value of one subframe and the correlation value of multiple subframes; according to Correlation values in multiple subframes are used to obtain the arrival time of reference signals for positioning neighbor cells. The symbols in this embodiment are OFDM (Orthogonal Frequency Division Multiplexing) symbols.

The method for measuring the time of arrival of the positioning neighbor cell reference signal provided in this embodiment, when there is a difference in the PRS bandwidth or the number of downlink subframes between the serving cell and the interfered positioning neighbor cell, based on the local positioning reference signal, respectively in the frequency domain or in time In the field, the interference of the PRS signal of the serving cell to the PRS signal of the interfered positioning neighbor cell is eliminated, so that the UE can achieve precise positioning.

FIG. 2 is a flowchart of a method for measuring and positioning neighbor cell reference signal arrival times based on frequency domain interference cancellation of local positioning reference signals according to Embodiment 2 of the present invention. As shown in Figure 2, the steps of measuring and positioning the arrival time of the neighbor cell reference signal include:

Step S201: Receive an OBTA measurement assistance message, and receive a received signal containing a positioning reference signal of the locating neighbor cell within a measurement opportunity according to the received OTDA measurement assistance message.

In this step, the UE obtains the OTDOA measurement assistance information issued by the upper layer. The measurement assistance information includes positioning reference cell information and positioning neighbor cell information. For details, see 3GPP TS 36.3556.5.1.2.

Obtain the configuration of the measurement opportunity according to receiving the observed time difference of arrival measurement auxiliary message, such as frequency layer, period, starting subframe number and other parameters. In addition, the UE also receives the measurement opportunity containing the The received signal of the positioning reference signal of the positioning neighbor cell.

Step S202: Judging whether the positioning reference cell is the serving cell, and whether it is within one measurement opportunity of the same frequency layer as the positioning neighbor cell.

In this step, the UE judges whether the positioning reference cell is the serving cell, and whether it is an Occasion (measurement opportunity) in the same frequency layer as the positioning neighbor cell; if yes, execute step S203; otherwise, consider that there is no strong interference, and execute step S209.

Step S203: judging whether the PRS bandwidth of the serving cell×the first threshold is less than or equal to the PRS bandwidth of the positioning neighbor cell.

According to the PRS bandwidth of the serving cell and the PRS bandwidth of the positioning neighbor cell in the OTDOA measurement assistance information, the UE judges whether the PRS bandwidth of the serving cell and the PRS bandwidth of the positioning neighbor cell meet the activation conditions of the frequency domain interference cancellation based on the local positioning reference signal, The condition is specifically: the PRS bandwidth of the serving cell×the first preset threshold≦the PRS bandwidth of the positioned neighbor cell. If so, execute step S204 to start the interference cancellation process based on the frequency domain of the local positioning reference signal; otherwise, return to step S209. Wherein, the first preset threshold is a real number greater than 1.

Step S204: According to the PRS information of the positioning neighbor cell in the observed time difference of arrival measurement assistance message, generate the local first frequency domain reference signal corresponding to the symbol in the downlink subframe sent by the positioning neighbor cell.

In this step, the UE locates the PRS starting slot number (prs-ConfigurationIndex field) of the neighbor cell in the neighbor cell list (OTDOA-NeighbourCellInfoList) and the PRS bandwidth (prs-Bandwidth ), the number of PRS downlink subframes (numDL-Frames field) and the cell identifier (phyCellid field), generate the local first frequency domain reference signal of the PRS symbol in the numDL-Frames field (downlink subframe) sent by the neighbor cell for positioning, specifically The method is defined in 3GPP TS 36.2116.10.4.

Step S205: among the local first frequency domain reference signals, the frequency domain signals within the PRS bandwidth of the serving cell are set to zero, and the local first time domain reference signal is generated by inverse fast Fourier transform (IFFT) transformation.

In this step, among the local first frequency domain reference signals, the frequency domain signals within the PRS bandwidth of the serving cell are set to zero, and the local first time domain reference signal is generated through IFFT transformation. The local first time-domain reference signal does not contain any signal in the frequency band of the serving cell, so as to achieve the effect of eliminating interference.

Step S206: Correlate the symbol of the local first time domain reference signal with the corresponding symbol of the received signal to obtain a correlation value in the corresponding symbol.

In this step, the UE correlates the symbol of the first time domain reference signal in the above step with the received signal in the time domain to obtain a correlation value in the corresponding symbol.

Step S207: Steps S204~S206 are repeated to obtain the correlation value in one subframe and the correlation values in multiple subframes.

In this step, the UE repeatedly executes steps S204~S206 to obtain the correlation value in one subframe and the correlation values in multiple subframes, and obtain the accumulated correlation value of multiple subframes through intra-subframe coherent addition and inter-subframe non-coherent addition .

Step S208: According to the correlation values in multiple subframes, the time of arrival of the reference signal of the positioning neighbor cell is obtained.

In this step, the UE estimates the delay of the earliest path through the strongest path according to the correlation values in multiple subframes, and obtains the arrival time of the reference signal of the positioning neighbor cell.

Step S209: Execute the method of non-interference cancellation, and perform the measurement of the arrival time of the positioning neighbor cell reference signal.

Specifically, the non-interference cancellation method is as follows: UE generates the local sequence of the positioning reference signal of the neighboring cell according to the PRS signal of the positioning neighbor cell in the observed time difference of arrival measurement assistance message; correlates the local sequence with the received signal, and obtains the corresponding Correlation value within a symbol; repeated execution to obtain a correlation value in one subframe and correlation values in multiple subframes; and obtain the arrival time of reference signals for positioning neighbor cells according to the correlation values in multiple subframes.

Fig. 3 is a schematic diagram of measuring and positioning neighbor cell reference signal arrival time based on frequency domain interference cancellation of a local positioning reference signal. Please refer to FIG. 3 , the horizontal axis is frequency (f), the vertical axis is power (p), the shaded part 1 is the PRS signal bandwidth of the serving cell, and the blank part 2 is the PRS signal bandwidth of the positioning neighbor cell.

It can be seen from FIG. 3 that in the frequency domain, the PRS bandwidth of the serving cell×the first preset threshold (BW_Fact_TH)≤the PRS bandwidth of the positioning neighbor cell. Specifically, BW_Fact_TH is a real number greater than 1. The bandwidth condition satisfies the starting condition of the frequency domain interference cancellation based on the local positioning reference signal. Therefore, in the embodiment of the present invention, the UE locates the PRS starting Slot number (calculated in the prs-ConfigurationIndex field), the PRS bandwidth (prs-Bandwidth field), and the number of PRS downlink subframes (numDL -Frames field) and the cell identifier (phyCellid field), generate the frequency domain signal for locating neighboring cells, that is, the signal within the bandwidth of the blank part 2, and according to the PRS bandwidth of the serving cell, the shaded part 1, that is, the signal within the PRS bandwidth of the serving cell The frequency domain signal is set to zero. That is to say, a frequency domain signal within the PRS bandwidth of the positioning neighbor cell and outside the PRS bandwidth of the serving cell is generated, and the local first time domain reference signal after interference cancellation is obtained through IFFT transformation. Then, correlate the symbol of the first time-domain reference signal with the received signal in the time domain to obtain the position of the maximum value, obtain the strongest path delay, estimate the earliest path delay according to the strongest path delay, and finally obtain the positioning neighbor cell Reference signal arrival time.

FIG. 4 is a flowchart of a method for measuring and positioning neighbor cell reference signal arrival times based on time-domain interference cancellation of local positioning reference signals according to Embodiment 3 of the present invention. As shown in Figure 4, the steps of measuring and positioning the arrival time of the neighbor cell reference signal include:

Step S401: Receive an OBTA measurement assistance message, and receive a received signal containing a positioning reference signal of the locating neighbor cell within a measurement opportunity according to the received OTDA measurement assistance message.

In this step, the UE obtains the OTDOA measurement assistance information issued by the upper layer, and the measurement assistance information includes positioning reference cell information and positioning neighbor cell information, see 3GPP TS36.3556.5.1.2 for details.

Obtain the configuration of the measurement opportunity according to receiving the observed time difference of arrival measurement auxiliary message, such as frequency layer, period, starting subframe number and other parameters. In addition, the UE also receives the received signal containing the positioning reference signal of the positioning neighbor cell within one measurement opportunity. .

Step S402: According to the observed time difference of arrival measurement service message, determine whether the positioning reference cell is the serving cell, and whether it is within a measurement opportunity of the same frequency layer as the positioning neighbor cell.

In this step, the UE judges whether the positioning reference cell is the serving cell by comparing pyhCellID, ceddGold, and earfcn in the positioning reference cell information; compares the eargcn and prs-mutinInfo in the positioning neighbor cell information according to the positioning reference cell information, and judges whether the serving cell is the same as Locating a measurement opportunity (Occasion) that the neighboring cells are in the same frequency layer; if yes, execute step S403; otherwise, execute step S409.

Step S403: judging whether the number of PRS downlink subframes of the serving cell×the second threshold is less than or equal to the number of PRS downlink subframes of the positioning neighbor cell.

In this step, the UE judges the number of PRS downlink subframes of the serving cell and the number of PRS downlink subframes for positioning neighbor cells according to the relationship between the number of PRS downlink subframes determined by the serving cell in the OTDOA measurement assistance information and the number of PRS downlink subframes for positioning neighbor cells Whether the relationship between the number of downlink subframes of the PRS satisfies the start condition of the time-domain interference cancellation based on the local positioning reference signal. The condition is specifically: the number of PRS downlink subframes of the serving cell×the second preset threshold≦the number of PRS downlink subframes of the positioning neighbor cell. If so, execute step S404 to start interference cancellation in the time domain based on the local positioning reference signal; otherwise, consider that there is no strong interference, and execute step S409. In this embodiment, the second preset threshold is a real number greater than 1.

Step S404: According to the expectedRSTD field, numDL-Frames field and numDL-Frames field of the serving cell in the PRS of the positioning neighbor cell in the observed time difference of arrival measurement assistance message, determine the expected subframe overlap time of the positioning neighbor cell reference signal and the serving cell reference signal.

Among them, the value range of ExpectedRSTD is 0~16383, and the unit is 3Ts, indicating the expected arrival time difference between the positioning reference cell and the serving cell. The expected RSTD can be calculated by (ExpectedRSTD-8192), the unit is 3Ts, one Ts=1/(15000×2048)s, one subframe is 30720Ts.

Step S405: According to the expected subframe overlap time and the PRS information of the positioning neighbor cell in the observed time difference of arrival measurement assistance message, generate a local second frequency domain reference for locating the PRS symbols sent by the neighbor cell within the unexpected subframe overlap time in the downlink subframe Signal.

In this step, the UE locates the neighbor cell's positioning reference signal starting Slot number (prs-ConfigurationIndex field) and PRS bandwidth (prs -Bandwith field), the number of PRS downlink subframes (numDL-Frames field) and cell identifier (pyhCellid field), and the PRS bandwidth of the serving cell, generate the corresponding subframe, locate the neighbor cell within the number of downlink subframes, except for overlapping with the serving cell A local PRS frequency domain signal on a resource element (Resource element, RE) other than the subframe of , that is, a local second frequency domain reference signal.

Step S406: Transform the local second frequency-domain signal reference signal through IFFT to generate the interference-canceled local second time-domain reference signal.

Step S407: Correlating the symbol of the local second time domain reference signal with the corresponding symbol of the received signal to obtain a correlation value in the corresponding symbol.

Step S408: Steps S404-S407 are repeatedly executed to obtain the correlation value in one subframe and the correlation values in multiple subframes, and obtain the arrival time of the positioning neighbor cell reference signal according to the correlation values in multiple subframes.

In this step, the UE obtains the maximum correlation value through the correlation value in one subframe and the correlation values in multiple subframes to obtain the strongest path delay, estimates the earliest delay according to the strongest delay, and finally obtains Locate neighbor cell reference signal arrival time.

Step S409: Execute the method of non-interference cancellation to measure the observed time difference of arrival.

For the execution process of this step, please refer to step S209 in FIG. 2 .

Fig. 5 is a schematic diagram of time-domain interference cancellation based on local positioning reference signal to measure arrival time of positioning neighbor cell reference signal. Please refer to Figure 5, the horizontal axis is the time domain (t), the vertical axis is the power (p), the shaded part 3 is the downlink subframe of the PRS signal of the serving cell, the blank part 4 is the PRS downlink subframe of the positioning neighbor cell, and the blank part 4' The downlink subframe of the neighboring cell is positioned for the overlapped downlink subframe of the serving cell.

It can be seen from Figure 5 that in the time domain, the number of PRS downlink subframes of the serving cell × the second preset threshold (SF_Faact_TH) ≤ the number of PRS downlink subframes of the neighbor cell. Specifically, SF_Fact_TH is a real number greater than 1, and the downlink The condition of the number of subframes satisfies the start condition of the time-domain interference cancellation process based on the local positioning reference signal. The UE locates the starting Slot number of the neighboring cell (calculated according to the prs-ConfigurationIndex field), the PRS bandwidth (prs-Bandwidth field), the number of PRS downlink subframes (numDL-Frames field) and the cell identity (pyhCellid) in the OTDOA measurement assistance message. field), and the number of PRS downlink subframes of the serving cell, to generate a local second frequency domain reference signal that locates the PRS symbols within the overlapping time of the unexpected subframes sent by the neighbor cell in the downlink subframe. That is to say, the UE will discard the downlink subframes overlapping with the downlink subframes of the serving cell to locate neighbor cells, that is, the blank part 4', and only use the local frequency domain signals on REs other than the subframes overlapping with the serving cell , that is, the remaining five blank parts 4 are used as local second frequency-domain reference signals. The local second time-domain reference signal after interference cancellation is obtained through IFFT transformation. Then, correlate the symbol of the local second time-domain reference signal with the received signal in the time domain, obtain the position of the maximum value, obtain the strongest path delay, estimate the earliest path delay according to the strongest path delay, and finally obtain the positioning neighbor cell Reference signal arrival time. In this embodiment, a downlink subframe of the serving cell and one of the six downlink subframes of the neighbor cell are completely overlapped within the expected subframe overlap time as an example to illustrate the specific implementation method of the embodiment of the present invention. The invention is not limited thereto. In other embodiments, the number of downlink subframes in the serving cell and the number of downlink subframes in the positioning neighbor cell, as well as the state of overlapping, may be determined according to specific circumstances.

In another embodiment of the present invention, if the signal strength of the PRS signal of the serving cell reaching the UE is greater than the signal strength of the PRS signal of the positioning neighbor cell reaching the UE by 13dB (200 times), that is, the received reference signal power (Reference Signal Received Power , RSRP) or Received Reference Signal Quality (Referecnce Signal Received Quality, RSRQ) is greater than or equal to 13dB, the PRS signal of the positioning neighbor cell may be due to the signal to interference and noise ratio (Signal to Interference and NoiseRatio, SINR) is too small, and the correlation is calculated in the time domain when the peak value is not obtained correctly. Therefore, in this embodiment, before judging whether the interference cancellation start condition is met, the UE can start the interference cancellation process by obtaining whether the ratio of the RSRP or RSRQ of the serving cell in the current Occasion to the positioning neighbor cell exceeds the third preset threshold, Specifically, the third preset threshold is greater than or equal to 13dB.

The method for measuring and positioning the reference signal arrival time of neighbor cells provided by the embodiments of the present invention, when there is a difference in the PRS bandwidth and the number of downlink subframes between the serving cell and the interfered cell, based on the local positioning reference signal, it is eliminated in the frequency domain or the time domain respectively. The serving cell interferes with the PRS signal of the interfered positioning neighbor cell, and then obtains the arrival time of the reference signal of the neighbor cell, so that the UE can be positioned.

FIG. 6 is a schematic diagram of a terminal for measuring and positioning neighbor cell reference signal arrival time according to Embodiment 1 of the present invention. As shown in FIG. 6 , the terminal for measuring and locating the arrival time of reference signals of neighboring cells includes: an acquiring unit 5 , a judging unit 6 and an interference eliminating unit 7 .

The obtaining unit is used to obtain the observed time difference of arrival measurement auxiliary message, the observed time difference of arrival measurement auxiliary message includes positioning reference cell information and positioning neighbor cell information, and the obtaining unit is also used to receive a measurement opportunity within the measurement opportunity according to the observed time difference of arrival measurement auxiliary message The signal containing the reference signal for locating neighbor cells.

The UE acquires the OTDOA measurement assistance message issued by the high layer through the acquisition unit 5, and the measurement assistance message includes positioning reference cell information and positioning neighbor cell information.

The judging unit is used to judge whether the positioning reference cell is a serving cell, and whether the measurement opportunity is in the same frequency layer as the positioning neighbor cell; the judging unit is also used to judge the starting condition of interference elimination; if satisfied, the received signal is started based on The frequency-domain interference cancellation processing of the local positioning reference signal or the time-domain interference cancellation processing based on the local positioning reference signal; otherwise, the non-interference cancellation processing is started.

The UE judges whether the positioning reference cell is the serving cell according to the phyCellID, cellGoldballd, earfcn, etc. in the positioning reference cell information obtained by the acquisition unit through the judgment unit 6; compares the earfcn and pre- mutingInfo, to determine whether the serving cell is in a measurement opportunity (Occasion) of the same frequency layer as the positioning neighbor cell; according to the relationship between the PRS bandwidth of the serving cell and the PRS bandwidth of the positioning neighbor cell or the number of downlink subframes of the serving cell PRS and the positioning neighbor The relationship between the number of PRS downlink subframes of the cell is used to determine whether the starting condition for interference cancellation is met.

The interference elimination unit 7 is configured to perform frequency domain interference elimination processing based on the local positioning reference signal or time domain interference elimination processing or non-interference elimination processing based on the local positioning reference signal on the received signal.

According to the relationship between the PRS bandwidth of the serving cell and the PRS bandwidth of the positioning neighbor cell determined by the judgment unit 6, the UE starts the frequency domain interference cancellation based on the local positioning reference signal, so as to eliminate the interference of the serving cell to the positioning reference signal of the positioning neighbor cell; Or, according to the relationship between the number of PRS downlink subframes of the serving cell and the number of PRS downlink subframes of the positioning neighbor cell judged by the judging unit 6, the time domain interference elimination processing based on the local positioning reference signal is started for the received signal; If the interference cancellation processing is performed in the time domain, the non-interference cancellation processing is started.

The terminal provided in this embodiment for measuring the arrival time of the reference signal of the positioning neighbor cell judges the PRS bandwidth or downlink of the serving cell and the disturbed positioning neighbor cell when the serving cell and the positioning neighbor cell are within one measurement opportunity of the same frequency layer When there is a difference in the number of subframes, based on the local positioning reference signal, the interference of the PRS signal of the serving cell to the PRS signal of the neighboring cell is eliminated in the frequency domain or the time domain, respectively, which improves the accuracy of the UE in obtaining the observed arrival time of the positioning neighbor cell, and then This enables the UE to be precisely positioned.

FIG. 7 is a schematic diagram of a terminal for measuring and positioning neighbor cell reference signal arrival time based on frequency domain interference cancellation of local positioning reference signals according to Embodiment 2 of the present invention. As shown in FIG. 7 , the terminal for measuring and locating the arrival time of reference signals of neighboring cells includes: an acquisition unit 5 , a frequency domain judgment unit 61 and a frequency domain interference elimination unit 71 .

The obtaining unit 5 is configured to obtain an observed time difference of arrival measurement auxiliary message, the observed time difference of arrival measurement auxiliary message includes positioning reference cell information and positioning neighbor cell information, and the obtaining unit is also used to receive a measurement according to the observed time difference of arrival measurement auxiliary message Within-opportunity Signal within one measurement opportunity containing positioning reference signals for locating neighboring cells.

The UE acquires the OTDOA measurement assistance message issued by the high layer through the acquisition unit 5, and the measurement assistance message includes positioning reference cell information and positioning neighbor cell information.

In addition to phyCellID, cellGoldballd, earfcn, etc. in the positioning reference cell information acquired by the acquisition unit 5, the frequency domain judgment unit 61 judges whether the positioning reference cell is a serving cell; the UE compares earfcn and pre-mutingInfo in the neighbor cell information according to the serving cell information, Judging whether the serving cell is in a measurement opportunity (Occasion) of the same frequency layer as the positioning neighbor cell; it is also used to judge whether the PRS bandwidth of the serving cell × the first preset threshold ≤ the PRS bandwidth of the positioning neighbor cell, that is, to determine whether A condition for enabling frequency domain interference, wherein the first preset threshold is a real number greater than 1.

The frequency domain interference elimination unit 71 specifically includes: a local first frequency domain reference signal generation unit 81 , a local first time domain reference signal generation unit 82 , a first correlation unit 83 and a first time acquisition unit 84 .

In the local first frequency domain reference signal generation unit 81, the UE generates the PRS in the numDL-Frames field (downlink subframe) sent by the positioning neighbor cell according to the PRS bandwidth information of the positioning neighbor cell in the OTDOA measurement assistance message obtained by the acquisition unit The symbol's local first frequency-domain reference signal.

In the local first time domain reference signal generating unit 82, the UE sets the frequency domain signal within the PRS bandwidth of the serving cell to zero in the local first frequency domain reference signal generated by the local first frequency domain reference signal generating unit, A local first time-domain reference signal is generated by IFFT.

In the first correlation unit 83, the UE correlates the symbol of the local first time domain reference signal generated in the local first time domain reference signal generation unit with the received signal, obtains the correlation value in the corresponding symbol, and repeatedly executes , to obtain the correlation value in one subframe and the correlation value in multiple subframes, and obtain the accumulated correlation value of multiple subframes through intra-subframe coherent addition and inter-subframe non-coherent addition, and then obtain the correlation maximum value to obtain the strongest path delay.

Finally, in the first time obtaining unit, the UE obtains the reference signal arrival time of the positioning neighbor cell according to a correlation maximum value of correlation values in multiple subframes.

The frequency domain interference elimination unit judges that the positioning reference cell is not the serving cell or the serving cell and the positioning neighbor cell are in different measurement opportunities of different frequency layers in the frequency domain judgment unit, or the serving cell and the positioning neighbor cell are in a different frequency layer. In the measurement opportunity and when the bandwidth of the serving cell and the bandwidth of the positioning neighbor cell do not meet the conditions for frequency domain interference cancellation to start, it is also used to perform the method of non-interference cancellation, perform observation time difference of arrival measurement, and locate the UE, that is, the conventional UE Targeting.

FIG. 8 is a schematic diagram of a terminal for measuring and positioning neighbor cell reference signal arrival time satisfying time-domain interference cancellation according to Embodiment 3 of the present invention. As shown in FIG. 8 , the terminal for measuring and positioning the arrival time of reference signals of neighboring cells includes: an acquisition unit 5 , a time domain judgment unit 62 , and a time domain interference elimination unit 72 .

The obtaining unit 5 is used to obtain the observed time difference of arrival measurement auxiliary message, the observed time difference of arrival measurement auxiliary message includes positioning reference cell information and positioning neighbor cell information, and the obtaining unit is also used to receive a measurement opportunity containing positioning neighbor cell information The signal of the positioning reference signal.

The UE acquires the OTDOA measurement assistance message issued by the high layer through the acquisition unit 5, and the measurement assistance message includes positioning reference cell information and positioning neighbor cell information.

The time domain judging module 62 is except according to phyCellID, cellGoldballd, earfcn etc. in the location reference cell information, judges whether the location reference cell is the serving cell; compares earfcn and pre-mutingInfo in the neighbor cell information according to the serving cell information, and judges whether the serving cell is the same as It is also used to determine whether the number of PRS downlink subframes of the serving cell × the second threshold is less than or equal to the number of PRS downlink subframes of the neighbor cell, that is, to judge Whether the condition for starting time-domain interference is met, wherein the first preset threshold is a real number greater than 1.

The time domain interference elimination unit 72 specifically includes: a local second frequency domain reference signal generation unit 91 , a local second time domain reference signal generation unit 92 , a second correlation unit 93 and a second time acquisition unit 94 .

In the local second frequency domain reference signal generation unit 91, the UE judges and locates the neighbor cell according to the expectedRSTD field of the PRS for positioning the neighbor cell and the numDL-Frames field of the serving cell and the neighbor cell in the OTDOA measurement assistance message acquired by the acquisition unit The expected subframe overlap time of the reference signal and the reference signal of the serving cell is measured, and the PRS information of the positioning neighbor cell in the auxiliary message is measured according to the expected subframe overlap time and the observed time difference of arrival, and the corresponding subframe is generated to locate the neighbor cell within the number of downlink subframes. A local PRS frequency domain signal on a resource element (Resource element, RE) other than a subframe overlapping with the serving cell, that is, a local second frequency domain reference signal.

In the local second time-domain reference signal generation unit 92, the UE uses the local second frequency-domain reference signal generated by the local second frequency-domain reference signal generation unit to generate a local second time-domain reference signal after interference cancellation through IFFT transformation .

The UE correlates the symbol of the local second time domain reference signal generated in the local second time domain reference signal generating unit with the received signal in the second correlation unit 93 to obtain the correlation value in the corresponding symbol, and repeatedly execute , to obtain the correlation value in one subframe and the correlation value in multiple subframes, and obtain the accumulated correlation value of multiple subframes through intra-subframe coherent addition and inter-subframe non-coherent addition, and then obtain the correlation maximum value to obtain the strongest path delay.

Finally, in the second time obtaining unit 94, the UE obtains the reference signal arrival time of the positioning neighbor cell according to the correlation maximum value of the correlation values in multiple subframes.

The time-domain interference elimination unit judges that the positioning reference cell is not the serving cell or the serving cell and the positioning neighbor cell are in different measurement opportunities of different frequency layers in the time-domain judgment unit, or the serving cell and the positioning neighbor cell are in a different frequency layer. In the measurement opportunity and when the number of downlink subframes of the serving cell and the number of downlink subframes of the positioning neighbor cell do not meet the conditions for starting the time-domain interference cancellation, it is also used to perform the method of non-interference cancellation to locate the arrival time of the reference signal of the neighbor cell Measurement is to locate the UE, that is, a general UE positioning method.

FIG. 9 is a schematic diagram of another terminal for measuring and positioning the arrival time of reference signals of neighbor cells according to the present invention. As shown in FIG. 9 , the terminal for measuring and locating the arrival time of reference signals of neighboring cells includes: a pre-judgment unit 0 , an acquisition unit 5 , a judgment unit 6 and an interference elimination unit 7 . In this embodiment, the functions and configurations of the acquiring unit 5, the judging unit 6, and the interference canceling unit 7 are the same as those shown in FIG. 6. Please refer to FIG. 6 for details.

Pre-judgment unit 0, used to judge the ratio of the received reference signal power (Reference Signal Received Power, RSRP) of the serving cell and the positioning neighbor cell or the ratio of the received reference signal quality (Referecnce Signal Received Quality, RSRQ) of the serving cell and the positioning neighbor cell Whether the ratio is greater than or equal to 13dB.

If the signal strength of the PRS signal of the serving cell reaching the UE is 13dB (200 times) greater than the signal strength of the PRS signal of the positioning neighbor cell reaching the UE, the PRS signal of the positioning neighbor cell may be due to the signal to interference and noise ratio (Signal to Interference and Noise Ratio) , SINR) is too small to correctly obtain the peak value when correlating in the time domain. Therefore, in the terminal provided by this embodiment, before judging whether the interference cancellation startup condition is satisfied, the UE can start by judging whether the RSRP or RSRQ of the positioning reference cell and the positioning neighbor cell in the current Occasion exceeds the third preset threshold through the pre-judgment unit In the interference elimination process, specifically, the third preset threshold is greater than or equal to 13dB.

To sum up, the method and device for measuring and positioning neighbor cell reference signal arrival time provided by the present invention, when there are differences in the PRS bandwidth and the number of downlink subframes between the serving cell and the interfered cell, based on the local positioning reference signal, respectively in the frequency domain Or eliminate the interference of the serving cell on the PRS signal of the disturbed positioning neighbor cell in the time domain, and then obtain the arrival time of the reference signal of the neighbor cell, so that the UE can be positioned.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (9)

1. A method for measuring and positioning neighbor cell reference signal arrival time, characterized in that, comprising: receiving an observed time difference of arrival measurement assistance message, where the observed time difference of arrival measurement assistance message includes positioning reference cell information and positioning neighbor cell information; According to the observed time difference of arrival measurement assistance message, receive a signal containing the positioning reference signal PRS of the positioning neighbor cell in one measurement opportunity; According to the observed time difference of arrival measurement assistance message, determine whether the positioning reference cell is a serving cell, and whether the positioning reference cell and the positioning neighbor cell are within the one measurement opportunity of a frequency layer; If the positioning reference cell is the serving cell and the positioning reference cell and the positioning neighbor cell are within the one measurement opportunity of the frequency layer, then further judge whether the interference cancellation activation condition is satisfied, if the interference elimination activation condition is satisfied , then start frequency-domain interference cancellation processing based on local positioning reference signal or time-domain interference cancellation processing based on local positioning reference signal on the received signal; otherwise, start non-interference cancellation processing. 2. The method of claim 1, wherein: The interference cancellation start condition is a start condition of the frequency domain interference cancellation process based on the local positioning reference signal or a start condition of the time domain interference cancellation process based on the local positioning reference signal; The starting condition of the frequency domain interference cancellation process based on the local positioning reference signal is that the PRS bandwidth of the serving cell × the first preset threshold ≤ the PRS bandwidth of the positioning neighbor cell; The starting condition of the processing of the time-domain interference cancellation based on the local positioning reference signal is that the number of PRS downlink subframes of the serving cell × the second preset threshold ≤ the number of PRS downlink subframes of the positioning neighbor cell; The first preset threshold and the second preset threshold are respectively real numbers greater than 1. 3. The method according to claim 1 or 2, wherein said starting frequency domain interference cancellation processing based on a local positioning reference signal for said received signal comprises: According to the PRS information of the positioning neighbor cell in the observed time difference of arrival measurement assistance message, generate a local first frequency domain reference signal for sending a PRS symbol in the downlink subframe by the positioning neighbor cell; In the local first frequency domain reference signal, frequency domain signals within the PRS bandwidth of the serving cell are set to zero, and the rest of the signals after zeroing are transformed by an inverse fast Fourier transform (IFFT) to generate a local first time domain reference signal; correlating the symbol of the local first time-domain reference signal with the symbol corresponding to the received signal to obtain a correlation value in the symbol; Repeat the above process to obtain the correlation value in one subframe and further obtain the correlation value in multiple subframes; According to the correlation values in the plurality of subframes, the time of arrival of the reference signal of the positioned neighbor cell is obtained. 4. The method according to claim 1 or 2, wherein said starting the time-domain interference cancellation processing based on the local positioning reference signal on the received signal comprises: Obtain the positioning reference signal of the serving cell and the positioning neighbor cell according to the expectedRSTD field of the positioning neighbor cell, the numDL-Frames field and the numDL-Frames field of the serving cell in the observed time difference of arrival measurement assistance message The expected subframe overlap time of the positioning reference signal; According to the expected subframe overlapping time and the PRS information of the positioning neighbor cell in the observed time difference of arrival measurement assistance message, generate the localization of the PRS symbol in the unexpected subframe overlapping time of the sending downlink subframe of the positioning neighbor cell a second frequency domain reference signal; Transforming the local second frequency domain reference signal through IFFT to generate a local second time domain reference signal; correlating the symbol of the local second time-domain reference signal with the symbol corresponding to the received signal to obtain a correlation value corresponding to the symbol; Repeat the above process to obtain the correlation value in one subframe, and further obtain the correlation value in multiple subframes; According to the correlation values in the plurality of subframes, the time of arrival of the reference signal of the positioned neighbor cell is obtained. 5. The method according to any one of claims 1-4, characterized in that before judging whether the interference cancellation start condition is satisfied, further comprising: Judging whether the ratio of the received positioning reference signal power or received reference signal quality of the serving cell and the positioning neighbor cell exceeds a third preset threshold, and when the ratio exceeds the third preset threshold, continue to judge whether the ratio is satisfied Interference cancellation start condition. 6. A terminal, characterized in that, comprising: The obtaining unit is used to obtain the observed time difference of arrival measurement auxiliary message, the observed time difference of arrival measurement auxiliary message includes positioning reference cell information and positioning neighbor cell information, and the obtaining unit is also used to receive a measurement opportunity containing positioning neighbor cell information a signal of a positioning reference signal; A judging unit, configured to judge whether the positioning reference cell is a serving cell, and whether the positioning reference cell and the positioning neighbor cell are within the one measurement opportunity of a frequency layer; If the positioning reference cell is a serving cell and the positioning reference cell and the positioning neighbor cell are within the one measurement opportunity of the frequency layer, the judging unit further judges the start condition of interference cancellation; if satisfied, Then start frequency-domain interference cancellation processing based on local positioning reference signal or time-domain interference cancellation processing based on local positioning reference signal on the received signal; if not, start non-interference cancellation processing; The interference elimination unit is configured to perform frequency domain interference elimination processing based on the local positioning reference signal or time domain interference elimination processing or non-interference elimination processing based on the local positioning reference signal on the received signal. 7. The terminal according to claim 6, wherein: The judging unit includes a frequency domain judging unit and/or a time domain judging unit; The frequency domain judging unit is configured to judge whether the interference cancellation satisfies the activation condition of the frequency domain interference cancellation based on the local positioning reference signal, and the activation condition of the frequency domain interference cancellation based on the local positioning reference signal is specifically: the The PRS bandwidth of the serving cell × the first preset threshold ≤ the PRS bandwidth of the positioned neighbor cell; The time domain judging unit is configured to judge whether the interference cancellation satisfies the activation condition of the time domain interference cancellation based on the local positioning reference signal, and the activation condition of the time domain interference cancellation based on the local positioning reference signal is specifically: the The number of PRS downlink subframes of the serving cell × the second preset threshold ≤ the number of PRS downlink subframes of the positioned neighbor cell; The first preset threshold and the second preset threshold are respectively real numbers greater than 1. 8. The terminal according to claim 6 or 7, wherein: The interference elimination unit includes a frequency domain interference elimination unit and/or a time domain interference elimination unit, wherein: The frequency domain interference elimination unit includes at least: A local first frequency-domain reference signal generation unit, configured to generate the PRS symbols in the downlink subframe sent by the positioning neighbor cell according to the PRS information of the positioning neighbor cell in the observed time difference of arrival measurement assistance message obtained by the acquisition unit a local first frequency domain reference signal; A local first time-domain reference signal generation unit, configured to zero-set the frequency-domain signals within the PRS bandwidth of the serving cell among the local first frequency-domain reference signals, and pass the rest of the zero-set signals through fast Fourier The Liye inverse transform IFFT transform generates the local first time-domain reference signal; The first correlation unit is configured to correlate the symbol of the local first time-domain reference signal with the corresponding symbol of the received signal, and obtain a correlation value in the corresponding symbol; repeat the execution to obtain the correlation value and multiples in a subframe Correlation values in subframes; A first time acquisition unit, configured to acquire the time of arrival of the reference signal of the positioning neighbor cell; The time domain interference elimination unit at least includes: A local second frequency domain reference signal generation unit, configured to obtain the expectedRSTD field, the numDL-Frames field of the neighbor cell and the numDL-Frames field of the serving cell in the observed time difference of arrival measurement assistance message to obtain the The expected subframe overlap time of the positioning reference signal of the serving cell and the positioning reference signal of the positioning neighbor cell; according to the expected subframe overlap time and the PRS information of the positioning neighbor cell in the observed time difference of arrival measurement assistance message, generate the Locating the local second frequency domain reference signal of the PRS symbol sent by the neighbor cell within the overlapping period of the unexpected subframe in the downlink subframe; a local second time-domain reference signal generating unit, configured to generate a local second time-domain reference signal by performing IFFT transformation on the local second frequency-domain reference signal; The second correlation unit is configured to correlate the symbol of the local second time-domain reference signal with the corresponding symbol of the received signal to obtain the correlation value in the corresponding symbol; repeat the execution to obtain the correlation value in one subframe, and further obtain multiple subframes Correlation values within; The second time obtaining unit is configured to obtain the arrival time of the reference signal of the positioning neighbor cell. 9. The terminal according to any one of claims 6-8, further comprising: A pre-judgment unit, configured to judge whether the ratio of received reference signal power or received reference signal quality between the serving cell and the positioning neighbor cell exceeds a third preset threshold, and when the ratio exceeds the third preset threshold, continue It is judged whether the starting condition of interference elimination is satisfied.

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