A first path detection method and system based on UWB CIR

Abstract

The application belongs to the technical field of communication, and discloses a first path detection method and system based on UWB CIR. The method accumulates the cross-correlation results of each symbol output to obtain a channel impulse response sequence; obtains a phase sequence and an absolute value sequence of the channel impulse response; performs sliding window extraction on the data of the phase sequence and the absolute value sequence with a certain window length; calculates the maximum phase deviation according to the data in the window for the phase sequence; calculates the maximum value, the minimum value, the mean value and the ratio of the first two data in the window for the absolute value sequence; determines whether the current window has a first path, etc. The method does not need to perform threshold calculation first, directly performs first path detection, increases the range of first path detection, does not have complex calculation in the detection process, is beneficial to engineering implementation, utilizes the phase and amplitude change characteristics of the first path channel impulse response, and has higher detection success rate and detection robustness.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of communication technology, and particularly relates to a first path detection method and system based on UWB CIR. BACKGROUND

[0002] The outdoor positioning technology based on GNSS is relatively mature, but in the indoor, the satellite signal is easily blocked and cannot complete the normal positioning service and the positioning accuracy cannot meet the service demand. In recent years, people's demand for high-precision positioning service is increasingly strong, according to statistics, 70%-80% of people's activities occur indoors, so it is of great significance to develop indoor positioning technology. Based on various different needs, many corresponding positioning technologies have been shown, and good results have been achieved, such as infrared, radio frequency identification, ultrasonic wave, WIFI, Bluetooth, Zigbee, visual positioning and other technologies. However, each has its own curve, either low positioning accuracy or harsh environment requirements, which cannot meet people's requirements for high-precision indoor positioning and sensing system and good environmental adaptability.

[0003] The UWB positioning technology has many advantages, such as high-precision indoor positioning, strong anti-interference ability, extremely wide bandwidth, fast transmission rate, small power consumption and other advantages compared with other wireless positioning technologies. In the positioning process based on the ranging result, the direct path (first path) is particularly important, and the robustness of the first path detection performance will directly affect the accuracy of the positioning result. Simple and reliable first path detection algorithm is one of the current research focuses.

[0004] Through the above analysis, the problems and defects of the prior art are that in the prior art, the first path detection process in the indoor positioning is complex, which is not conducive to engineering implementation, and the detection success rate and the robustness of the detection are poor. SUMMARY

[0005] In order to overcome the problems in the related art, the present application discloses a first path detection method and system based on UWB CIR, which specifically relates to ultra-wide bandwidth (UWB) communication positioning technology.

[0006] The technical solution is as follows: a first path detection method based on UWB CIR, comprising:

[0007] S1, accumulating the cross-correlation results of each symbol output to obtain a channel impulse response sequence;

[0008] S2, respectively calculating the phase and absolute value of the channel impulse response sequence to obtain a phase sequence and an absolute value sequence of the channel impulse response;

[0009] S3, sliding window with a certain window length, extracting the phase sequence and absolute value sequence data;

[0010] S4, for the phase sequence, calculating the maximum phase deviation according to the data in the window;

[0011] S5, for the absolute value sequence, calculating the maximum value, minimum value, mean value, and the ratio of the first two data in the window;

[0012] S6, using the calculated results and the relevant threshold to determine whether the current window exists the first path;

[0013] S7, if there is no first path, updating the noise maximum value, returning to step S3 to continue extracting the data of the next window for calculation;

[0014] S8, if there is a first path, the algorithm ends, outputs the first path detection success, and outputs the first path related information;

[0015] S9, if there is no first path detected until the end of the sequence, the algorithm ends, and outputs the first path detection failure.

[0016] In step S1, the calculation formula of the channel impulse response sequence is:

[0017]

[0018] In the formula, C(i) is the i-th data in the channel impulse response sequence, C(i) is a complex number; N symb represents the total number of symbols, A k (i) is the correlation result of the i-th data in the k-th symbol.

[0019] In step S2, the phase and absolute value of the channel impulse response sequence are calculated respectively to obtain the phase sequence and absolute value sequence of the channel impulse response, and the expression is:

[0020] p'(i) = angle(C(i))

[0021] In the formula, p'(i) is the phase value calculated according to the channel impulse response, angle is the angle value, i is the index value of C(i) in the channel impulse response sequence, ranging from 1 to N CIR , N CIR is the total number of data contained in the channel response sequence;

[0022] When i = 1, p(i) = p'(i).

[0023] When i>1, judge the result of (p'(i)-p(i-1)), if (p'(i)-p(i-1))>180°, then p(i)=p'(i)-360°, if (p'(i)-p(i-1))<-180°, then p(i)=p'(i)+360°, otherwise, p(i)=p'(i).

[0024] Wherein, p(i) is the phase value of the i-th phase in the phase sequence.

[0025] Further, the method for calculating the absolute value sequence according to the channel impulse response sequence is as follows:

[0026] S(i)=abs(C(i

[0027] In the formula, S(i) is the i-th absolute value amplitude in the absolute value sequence, and abs(x) is an absolute value operation on x;

[0028] In step S3, a certain window length is N w =3, and the phase sequence and the absolute value sequence use respective sliding windows;

[0029] The index value of the first data in the sliding window represents the index of the current window;

[0030] The data with the lowest index is discarded and a data with a high index is added each time the sliding window slides.

[0031] In step S4, the maximum phase deviation calculation method is as follows:

[0032] Δp max (i)=max([p(i),…,p(i+N w -1)])-min([p(i),…,p(i+N w -1)])

[0033] In the formula, Δp max (i) is the maximum phase deviation, max(x) is the maximum value in the sequence x, min(x) is the minimum value in the sequence x, and N w is the window length of the sliding window.

[0034] Further, the calculation method of the maximum value in the current window is as follows:

[0035] S max (i)=max([S(i),…,S(i+N w -1)])

[0036] In the formula, S max (i) is the maximum value in the current sliding window;

[0037] The calculation method of the minimum value in the current window is as follows:

[0038] S min (i) = min([S(i),...,S(i+N w -1)])

[0039] In the formula, S min (i) is the minimum value in the current sliding window;

[0040] The calculation method of the average value in the current window is as follows:

[0041]

[0042] In the formula, S avg (i) is the average value in the current sliding window, and τ is a variable traversing i~i+N w -1.

[0043] In step S5, the calculation method of the ratio of the first two data in the sliding window is as follows:

[0044] R(i) = S(i) / max(S(i+1),d min )

[0045] In the formula, R(i) is the ratio of the first two data in the sliding window, S(i) is the absolute value corresponding to C(i), S(i) = abs(C(i)), and abs(x) is an absolute value operation on x; d min is the minimum value that S(i) can take except 0; when S(i+1)<d min , the dividend is replaced by d min .

[0046] In step S6, the method for determining whether the current window exists a first path is that the following conditions are met at the same time:

[0047] The maximum phase deviation is less than a set threshold: Δp max (i)<Δp th ;

[0048] The maximum value is less than the average value multiplied by a set proportion coefficient: S max (i)<R s *S avg (i);

[0049] The minimum value is greater than the maximum value of noise: S min (i)>S noi_max ;

[0050] The ratio of the first two data in the window satisfies a certain relationship: R(i)<R th ;

[0051] wherein Δp th is a maximum phase difference threshold, R s is a maximum value to average value ratio threshold, S noi_max is a maximum value of a noise segment, and is initialized as 0 and updated in step S7, R th is a ratio threshold of the first two data in the window.

[0052] In step S7, the method of updating the noise maximum value S max is as follows: when the current window is detected to have no first path, the maximum value S noi_max of the current window is compared with the currently stored noise maximum value S max (i), and when i noi_max > S noi_max , S max = S noi_max (i). Otherwise, S noi_max remains unchanged. The initial value of the noise maximum value S CIR is 0.

[0053] In step S8, the output first path information includes: the current window index i is the index value of the first path front point, the absolute value sequence in the current window is the amplitude information of the first path, and the phase sequence in the current window is the phase information of the first path.

[0054] In step S9, the output first path detection failure includes: when the count index i does not satisfy i w -N CIR , the sequence ends, and the first path is still not detected, the first path detection failure is output.

[0055] Another object of the present application is to provide a first path detection system based on a UWB CIR, which implements the first path detection method based on the UWB CIR, and the system comprises:

[0056] A channel impulse response sequence obtaining module is configured to accumulate the cross-correlation results output by each symbol to obtain a channel impulse response sequence.

[0057] A phase sequence and absolute value sequence obtaining module is configured to obtain a phase sequence and an absolute value sequence of the channel impulse response by respectively calculating the phase and the absolute value of the channel impulse response sequence.

[0058] A phase sequence and absolute value sequence data extracting module is configured to extract data of the phase sequence and the absolute value sequence by sliding a window with a certain length.

[0059] A maximum phase deviation calculating module is configured to calculate the maximum phase deviation according to the data in the window for the phase sequence.

[0060] A ratio calculation module is configured to calculate the maximum value, the minimum value, the average value and the ratio of the first two data in the window for the absolute value sequence.

[0061] A current window first path judgment module is configured to compare the calculated result with a related threshold to determine whether the current window has a first path.

[0062] An updated noise maximum value module is configured to update the noise maximum value if there is no first path, and return to step S3 to continue extracting the data of the next window for calculation.

[0063] A first path related information output module is configured to output the first path detection success and output the first path related information if there is a first path.

[0064] A first path detection failure output module is configured to output the first path detection failure if there is no first path detected until the end of the sequence.

[0065] In combination with all the technical solutions described above, the present application has the following beneficial effects: the present application does not need to calculate the threshold value by using the channel impulse response sequence (CIR), and can directly perform the first path detection; in the detection process, there is no complex calculation, which is beneficial to engineering implementation; meanwhile, the phase and amplitude change characteristics of the first path channel impulse response are utilized, and the present application has higher detection success rate and detection robustness. BRIEF DESCRIPTION OF DRAWINGS

[0066] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the disclosure;

[0067] Figure 1 FIG. 1 is a flow chart of a first path detection method based on UWB CIR provided by an embodiment of the present application;

[0068] Figure 2 FIG. 2 is a schematic diagram of window extraction data principle of the first path detection method based on UWB CIR;

[0069] Figure 3 FIG. 3 is a schematic diagram of sliding window sliding principle of the first path detection method based on UWB CIR;

[0070] Figure 4 FIG. 4 is a schematic diagram of a first path detection system based on UWB CIR provided by an embodiment of the present application;

[0071] In the figure: 1, channel impulse response sequence obtaining module; 2, phase sequence and absolute value sequence obtaining module; 3, phase sequence and absolute value sequence data extracting module; 4, maximum phase deviation calculating module; 5, ratio calculating module; 6, current window first path judging module; 7, updating noise maximum value module; 8, first path related information output module; 9, first path detection failure output module. DETAILED DESCRIPTION

[0072] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of ways beyond the specific details described herein. Thus, the present application is not intended to be limited to the embodiments described herein and illustrated in the drawings.

[0073] The present application does not need to use CIR to calculate a threshold value, and directly performs first path detection, thereby increasing the range of first path detection. In the detection process, there is no complex calculation, which is beneficial to engineering implementation. Meanwhile, the phase and amplitude variation characteristics of the first path channel impulse response are utilized, and the present application has higher detection success rate and detection robustness.

[0074] Embodiment 1, as shown in the figure, the first path detection method based on UWB CIR provided by the embodiment of the present application comprises the following steps: Figure 1

[0075] S1, accumulating the cross-correlation results output by each symbol to obtain a channel impulse response sequence;

[0076] S2, calculating the phase and absolute value of the channel impulse response sequence respectively to obtain a phase sequence and an absolute value sequence of the channel impulse response;

[0077] S3, performing sliding window with a certain window length to extract the data of the phase sequence and the absolute value sequence;

[0078] S4, for the phase sequence, calculating the maximum phase deviation according to the data in the window;

[0079] S5, for the absolute value sequence, calculating the maximum value, minimum value, mean value, and ratio of the first two data in the window;

[0080] S6, comparing the calculated results with a related threshold value to determine whether the current window has a first path;

[0081] S7, if there is no first path, updating the noise maximum value, and returning to step S3 to continue extracting the data of the next window for calculation;

[0082] ​S8, if there is a preamble, the algorithm ends, output the preamble detection success, output the preamble related information;

[0083] S9, if to the end of the sequence, no preamble is detected, the algorithm ends, output the preamble detection failure.

[0084] Exemplary, in step S1, the calculation method of the channel impulse response sequence is calculated by the formula:

[0085]

[0086] Wherein, A k (i) is the correlation result of the i-th data in the k-th symbol. N symb The total number of symbols. In step S2, the method for calculating the phase sequence according to the channel impulse response sequence is as follows:

[0087] p'(i) = angle(C(i))

[0088] Wherein, p'(i) is the phase value calculated according to the channel impulse response, C(i) is the i-th data in the channel impulse response sequence, C(i) is a complex number. i is the index value of C(i) in the channel impulse response sequence, ranging from 1 to N CIR , N CIR is the total number of data contained in the channel response sequence.

[0089] When i = 1, p(i) = p'(i).

[0090] When i > 1, judge the result of (p'(i)-p(i-1)), if (p'(i)-p(i-1))>180°, then p(i) = p'(i)-360°, if (p'(i)-p(i-1))<-180°, then p(i) = p'(i)+360°, otherwise, p(i) = p'(i);

[0091] Wherein, p(i) is the phase value of the i-th phase in the phase sequence.

[0092] The method for calculating the absolute value sequence according to the channel impulse response sequence is as follows:

[0093] S(i = abs(C(i));

[0094] Wherein, S(i) is the i-th absolute value amplitude in the absolute value sequence, and abs(x) is the absolute value operation on x.

[0095] Exemplary, in step S3, the window length is set to N w = 3, that is, the sliding window contains 3 data. And the phase sequence and the absolute value sequence use their respective sliding windows.

[0096] For example, the method of extracting data in each sliding window of phase sequence is shown in Figure 2 .

[0097] As shown in Figure 3 , the index value of the first data in the sliding window also represents the index of the current window. For example, the data in the initial window is [p(1) p(2) p(3)], and the index of the current window is 1.

[0098] After each sliding of the sliding window, the data with the lowest index will be discarded, and a data with a higher index will be added. For example, after the first sliding of the sliding window, p(1) is discarded, and p(4) is added to the window, and the number of data used in the window remains 3.

[0099] In step S4, the maximum phase deviation calculation method is as follows:

[0100] Δp max (i) = max([p(i), …, p(i+N w -1)]) - min([p(i), …, p(i+N w -1])

[0101] Where max(x) is the maximum value in the sequence x, min(x) is the minimum value in the sequence x, and N w is the window length of the sliding window.

[0102] In step S5, for the absolute value sequence, the maximum value, the minimum value, the average value in the window, and the ratio of the first two data are calculated, and the calculation method of the maximum value in the current window is as follows:

[0103] S max (i) = max(S(i), …, S(i+N w -1])

[0104] Where S max (i) is the maximum value in the current sliding window.

[0105] The calculation method of the minimum value in the current window is as follows:

[0106] S min (i) = min([S(i), …, S(i+N w -1]);

[0107] Where S min (i) is the minimum value in the current sliding window.

[0108] The calculation method of the average value in the current window is as follows:

[0109]

[0110] where S avg (i) is the average value in the current sliding window, τ is the variable traversing i~i+N w -1. The calculation method of the ratio of the first two data in the sliding window is as follows:

[0111] R(i) = S(i) / max(S(i+1), d min )

[0112] where R(i) is the ratio of the first two data in the sliding window, S(i) is the absolute value corresponding to C(i), S(i) = abs(C(i)), and abs(x) is the absolute value operation on x. d min is the minimum value that S(i) can take except 0. When S(i+1) < d min , the dividend is replaced by d min .

[0113] In step S6, the method for judging whether the current window exists the first path is as follows:

[0114] The current window exists the first path when the following conditions are met simultaneously:

[0115] The maximum phase deviation is less than the set threshold: Δp max (i) < Δp th ;

[0116] The maximum value is less than the average value multiplied by the set proportion coefficient: S max (i) < R s *S avg (i);

[0117] The minimum value is greater than the maximum value of the noise: S min (i) > S noi_max ;

[0118] The ratio of the first two data in the window meets a certain relationship: R(i) < R th .

[0119] where Δp th is the maximum phase difference threshold, R s is the maximum value and average value proportion coefficient threshold in the sliding window, S noi_max is the maximum value of the noise segment, the initial value is 0, and is updated in step S7, R th is the ratio threshold of the first two data in the window.

[0120] In step S7, the method for updating the maximum value of the noise is as follows:

[0121] When the current window is detected to not exist the first path, the maximum value S max(i) with the currently stored maximum noise value S noi_max Comparison, when S max (i)>S noi_max At that time, S noi_max =S max (i). Otherwise, S noi_max Keep it unchanged.

[0122] maximum noise S noi_max The initial value is 0.

[0123] For example, in step S8, when all four conditions of step S7 are met simultaneously, it indicates that the current window has a first path, the first path detection is successful, and the first path information is output.

[0124] The output first diameter information includes: the current window index i is the index value of the first diameter leading edge point, the absolute value sequence within the current window is the amplitude information of the first diameter, and the phase sequence within the current window is the phase information of the first diameter.

[0125] For example, in step S9, when the counting index i does not satisfy i≤(N) CIR -N w This indicates that the sequence has ended and the first diameter has still not been detected, so the output "First diameter detection failed" is displayed.

[0126] Example 2, as Figure 4 As shown, the UWB CIR-based head diameter detection system provided in this embodiment of the invention includes the following steps:

[0127] Module 1, which obtains the channel impulse response sequence, is used to accumulate the cross-correlation results of each symbol output to obtain the channel impulse response sequence.

[0128] Phase sequence and absolute value sequence acquisition module 2 is used to calculate the phase and absolute value of the channel impulse response sequence, respectively, to obtain the phase sequence and absolute value sequence of the channel impulse response;

[0129] Phase sequence and absolute value sequence data extraction module 3 is used to extract phase sequence and absolute value sequence data by sliding window with a certain window length;

[0130] Maximum phase deviation calculation module 4 is used to calculate the maximum phase deviation for a phase sequence based on the data in the window.

[0131] The ratio calculation module 5 is used to calculate the maximum, minimum, and mean values ​​within a window, as well as the ratio of the first two data points, for an absolute value sequence.

[0132] The current window first path determination module 6 is used to compare the calculated result with relevant thresholds to determine whether the current window has a first path;

[0133] The updating noise maximum value module 7 is used for updating the noise maximum value if there is no first path, and continuing to extract data of the next window for calculation;

[0134] The first path related information output module 8 is used for ending the algorithm if there is the first path, outputting that the first path detection is successful, and outputting the first path related information.

[0135] The first path detection failure output module 9 is used for ending the algorithm if no first path is detected until the end of the sequence, and outputting that the first path detection is failed.

[0136] In the above embodiments, the description of each embodiment has its own emphasis, and the part not described or recorded in a certain embodiment can be referred to the related description of other embodiments.

[0137] The above describes only the preferred specific embodiments of the present application, but the protection scope of the present application is not limited to this. Any modification, equivalent replacement and improvement made by those skilled in the art within the technical range disclosed by the present application and within the spirit and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A UWB CIR-based first path detection method, characterized in that, The method comprises: S1, accumulating the cross-correlation results of each symbol output to obtain a channel impulse response sequence; S2, calculating the phase and absolute value of the channel impulse response sequence respectively to obtain a phase sequence and an absolute value sequence of the channel impulse response; S3, performing sliding window with a certain window length to extract data of the phase sequence and the absolute value sequence; S4, for the phase sequence, calculating the maximum phase deviation according to the data in the window; S5, for the absolute value sequence, calculating the maximum value, the minimum value, the average value, and the ratio of the first two data in the window; S6, comparing the calculated results with a related threshold to determine whether there is a first path in the current window; S7, if there is no first path, updating the maximum noise value and returning to step S3 to continue extracting data of the next window for calculation; S8, if there is a first path, the algorithm ends, and first path detection success is output, and first path related information is output; S9, if no first path is detected until the end of the sequence, the algorithm also ends, and first path detection failure is output; In step S6, the method for determining whether there is a first path in the current window simultaneously satisfies the following conditions, indicating that there is a first path in the current window: maximum phase deviation is less than a set threshold: Δp max (i) < Δp th ; Maximum value is less than average value multiplied by a set proportionality factor: S max (i) < R s *S avg (i); Minimum value greater than maximum value of noise: S min (i) > S noi_max ; The ratio of the first two data in the window satisfies a certain relationship: R(i) < R th ; In the formula, Δp th is a maximum phase difference threshold, R s is a maximum value to average value ratio coefficient threshold in a sliding window, S noi_max is a maximum value of a noise section, an initial value is 0, and is updated in step S7, R th is a ratio threshold of the first two data in a window.

2. The UWB CIR-based first path detection method of claim 1, wherein, In step S1, the calculation formula for obtaining the channel impulse response sequence is: where C(i) is the ith data in the channel impulse response sequence, C(i) is a complex number; N symb denotes the total number of symbols, A k (i) is the cross-correlation result of the ith data in the kth symbol. 3.The UWB CIR-based first path detection method of claim 2, wherein, In step S2, the phase sequence and the absolute value sequence of the channel impulse response are obtained by calculating the phase and the absolute value of the channel impulse response sequence, and the expression is: p'(i) = angle(C(i)) where p'(i) is a phase value calculated from the channel impulse response, angle is an angle value, i is an index value of C(i) in the channel impulse response sequence, and ranges from 1 to N CIR , N CIR is the total number of data included in the channel response sequence; When i = 1, p(i) = p'(i); When i > 1, the result of (p'(i) - p(i-1)) is judged, if (p'(i) - p(i-1)) > 180°, then p(i) = p'(i) - 360°, if (p'(i) - p(i-1)) < -180°, then p(i) = p'(i) + 360°, otherwise, p(i) = p'(i); Wherein, p(i) is the phase value of the i-th phase in the phase sequence.

4. The UWB CIR-based first path detection method of claim 3, wherein, The method for calculating the absolute value sequence according to the channel impulse response sequence is as follows: S(i) = abs(C(i)) In the formula, S(i) is the i-th absolute value amplitude in the absolute value sequence, and abs(x) is the absolute value operation on x; In step S3, a certain window length is N w = 3, and the phase sequence and the absolute value sequence use respective sliding windows, respectively. The index value of the first data in the sliding window represents the index of the current window; Each time the sliding window slides, the data with the lowest index will be discarded, and a data with a higher index will be added.

5. The UWB CIR-based first path detection method of claim 4, wherein, In step S4, the maximum phase deviation calculation method is as follows: Δp max (i) = max([p(i),...,p(i+N w -1)]|) - min([p(i),...,p(i+N w -1)]) where Δp max (i) is the maximum phase deviation, max(x) is the maximum value in the sequence x, min(x) is the minimum value in the sequence x, N w is the window length of the sliding window.

6. The UWB CIR-based first path detection method of claim 5, wherein, The calculation method of the maximum value in the current window is as follows: S max (i) = max([S(i),...,S(i+N w -1)]) In the formula, S max (i) is the maximum value within the current sliding window; The calculation method of the minimum value in the current window is as follows: S min (i) = min([S(i),...,S(i+N w -1)]) In the formula, S min (i) is the minimum value within the current sliding window; The calculation method of the average value in the current window is as follows: where S avg (i) is the average value within the current sliding window, τ is the variable that traverses i ~ i + N w - 1.

7. The UWB CIR based first path detection method of claim 1, wherein, In step S5, the calculation method of the ratio of the first two data in the sliding window is as follows: R(i) = S(i) / max(S(i+1), d min ) In the formula, R(i) is the ratio of the first two data in the sliding window, S(i) is the absolute value corresponding to C(i), S(i)=abs(C(i)), and abs(x) is the absolute value of x; d min is the minimum value that can occur except 0; when S(i+1) min is less than d min , the dividend is replaced by d 8. The UWB CIR based first path detection method of claim 1, wherein, In step S7, the method for updating the maximum noise value is as follows: when the current window has been detected as having no first path, the maximum value S of the current window is used. max (i) with the currently stored maximum noise value S noi_max Comparison, when S max (i)>S noi_max At that time, S noi_max =S max (i); otherwise, S noi_max Remain unchanged; maximum noise value S noi_max The initial value is 0; In step S8, the output first path information includes: the current window index i is the first path front edge point index value, the absolute value sequence in the current window is the amplitude information of the first path, and the phase sequence in the current window is the phase information of the first path; In step S9, the output of the first path detection failure includes: when the count index i does not satisfy i≤(N CIR -N w ), the sequence ends, and the first path is still not detected, the output of the first path detection failure. 9.A UWB CIR-based first path detection system, characterized in that, The system implements the first path detection method based on UWB CIR according to any one of claims 1-8, and the system comprises: The channel impulse response sequence obtaining module (1) is configured to accumulate the cross-correlation results output by each symbol to obtain a channel impulse response sequence; The phase sequence and absolute value sequence obtaining module (2) is configured to obtain a phase sequence and an absolute value sequence of the channel impulse response by respectively calculating the phase and the absolute value of the channel impulse response sequence; The phase sequence and absolute value sequence data extracting module (3) is configured to extract data of the phase sequence and the absolute value sequence by sliding a window with a certain length; The maximum phase deviation calculating module (4) is configured to calculate the maximum phase deviation according to the data in the window for the phase sequence; The ratio calculating module (5) is configured to calculate the maximum value, the minimum value, the average value and the ratio of the first two data in the window for the absolute value sequence; The current window first path judging module (6) is configured to compare the calculated result with a related threshold to determine whether the current window has a first path; The noise maximum value updating module (7) is configured to update the noise maximum value if there is no first path, and return to step S3 to continue extracting the data of the next window for calculation; The first path related information output module (8) is configured to output the first path detection success and output the first path related information if there is a first path, and the algorithm ends; The first path detection failure output module (9) is configured to output the first path detection failure if no first path is detected until the sequence ends, and the algorithm ends.

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