WO2023061296A1

WO2023061296A1 - Signal transmission method, signal processing method and related apparatus

Info

Publication number: WO2023061296A1
Application number: PCT/CN2022/124130
Authority: WO
Inventors: 阳光耀; 胡烜; 石现领; 黄志臻
Original assignee: 华为技术有限公司
Priority date: 2021-10-13
Filing date: 2022-10-09
Publication date: 2023-04-20
Also published as: CN115963479A

Abstract

A signal transmission method (100), a signal processing method (200, 300) and a related apparatus (1300, 1400, 1500, 1600, 1700), which can be applied to a laser radar (101) and are used in the fields of autonomous driving, assisted driving, intelligent driving, surveying and mapping, etc. The signal transmission method (100) comprises: determining N pulse sequences according to an encoding matrix, and transmitting the N pulse sequences, wherein each pulse sequence corresponds to each row of the encoding matrix, and N is an integer greater than or equal to 2. The encoding matrix of the N pulse sequences is determined to be an N-order reversible matrix, which is conducive to avoiding the sidelobe influence when decoding processing is subsequently performed on an echo signal according to an inverse matrix of the encoding matrix. In addition, the difference between an absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is less than a first preset value, which is conducive to improving a noise suppression effect during decoding processing, such that the long-distance measurement capability of the laser radar (101) can be improved.

Description

A signal transmission and processing method and related device

This application claims the priority of a Chinese patent application filed with the State Intellectual Property Office of China on October 13, 2021, with the application number 202111192739.3, and the title of the application is "a signal transmission, processing method and related device", the entire content of which is incorporated by reference incorporated in this application.

technical field

The present application relates to the field of perception technology, and in particular to a signal transmission and processing method and a related device.

Background technique

The advanced driver assistance system (advanced driver assistance system, ADAS) can realize different levels of automatic driving assistance based on artificial intelligence algorithms and information obtained by multiple sensors. Among them, LiDAR in multi-sensor is the abbreviation of light laser detection and ranging (LiDAR). LiDAR can use time of flight (ToF) technology to achieve ranging, that is, LiDAR emits high-power super Short optical pulses, based on the interval between the echo reception time and emission time after the optical pulse is reflected by the target, the distance measurement is realized.

Long-distance measurement capability is an important feature of lidar. How to improve the long-distance measurement capability of lidar is an urgent problem to be solved.

Contents of the invention

Embodiments of the present application provide a signal transmission and processing method and a related device, which are beneficial to improving the long-distance measurement capability of the laser radar.

In a first aspect, the embodiment of the present application provides a signal transmitting method. In this method, N pulse sequences are determined according to the coding matrix, and the N pulse sequences are transmitted. Wherein, the encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is smaller than the first preset value, and each pulse sequence corresponds to each One line, N is an integer greater than or equal to 2.

It can be seen that the method determines and transmits N pulse sequences according to the encoding matrix. The reversibility of the encoding matrix is beneficial to the subsequent decoding of the received echo signal according to the inverse matrix of the encoding matrix. Instead of realizing pulse compression through cross-correlation operations, pulse compression is achieved by linear combination operations of encoding matrices, thereby avoiding The influence of side lobes improves the long-distance measurement capability of lidar. In addition, the difference between the absolute value of each element in the inverse matrix of the coding matrix and 2/(N+1) is smaller than the first preset value, which is beneficial to improving the noise suppression effect during subsequent decoding processing, thereby improving the signal-to-noise ratio, Improve the long-distance measurement capability of lidar.

In an optional implementation manner, before determining the N pulse sequences according to the encoding matrix, it also includes: deleting the first row and the first column of the first matrix to obtain the second matrix; replacing the element 1 in the second matrix with 0 , replace the element -1 in the second matrix with 1 to obtain the encoding matrix. Wherein, any two rows of the first matrix are mutually orthogonal, and the product between the first matrix and the transpose of the first matrix is an identity matrix, and the first matrix is a Hadamard matrix of order N+1.

It can be seen that this method is to perform correlation processing on the N+1-order Hadamard matrix to obtain the N-order encoding matrix, so that the encoding matrix has the above-mentioned reversibility, and make the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+ 1) The difference is smaller than the first preset value.

In an optional implementation, the absolute value of each element in a row of the encoding matrix is the amplitude value of each pulse signal in the corresponding pulse sequence, and one element corresponds to a time window, and the time window is used to send the element Corresponding pulse signal.

It can be seen that the absolute value of each element in a row of the encoding matrix is the amplitude value of each pulse signal in the corresponding pulse sequence, indicating that a high-power pulse signal is transmitted within the time window corresponding to element 1 in a row of the encoding matrix. The pulse signal without power is transmitted in the time window corresponding to element 0 in a row of the coding matrix, that is, no pulse signal is transmitted in the time window corresponding to element 0 in a row of the coding matrix. Therefore, transmitting N pulse sequences is sequentially transmitting high-power pulse signals within the time window corresponding to element 1 in each row of the coding matrix.

In an optional implementation manner, the time between the end time of the time window corresponding to the last pulse signal in the first pulse sequence and the start time of the time window corresponding to the first pulse signal in the second pulse sequence Interval, equal to or greater than the maximum round-trip time. The first pulse sequence and the second pulse sequence are pulse sequences corresponding to two adjacent rows in the coding matrix respectively, and the maximum round-trip time is the maximum round-trip time between a pulse signal and the measured object.

It can be seen that the transmission interval of two pulse sequences corresponding to two adjacent rows in the coding matrix is equal to or greater than the maximum value of the round-trip time between the pulse signal and the measured object, so as to avoid the occurrence of two pulse sequences during transmission or reflection. overlapping.

In a second aspect, the embodiment of the present application further provides a signal processing method. In the method, the echo signals of N pulse sequences are received; according to the inverse matrix of the coding matrix, the echo signals of the N pulse sequences are decoded to obtain the echo signals of a single pulse signal. Among them, the single pulse signal is a pulse signal in N pulse sequences, the encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is less than the first A preset value, N is an integer greater than or equal to 2.

It can be seen that this method decodes the echo signals of N pulse sequences according to the inverse matrix of the coding matrix. The reversibility of the coding matrix makes it possible to decode the echo signal according to the inverse matrix of the coding matrix, instead of realizing the pulse compression through the cross-correlation operation, but using the linear combination operation to realize the pulse compression, so as to avoid the influence of the side lobe and improve the laser radar performance. long distance measurement capability. In addition, the difference between the absolute value of each element in the inverse matrix of the coding matrix and 2/(N+1) is smaller than the first preset value, which can improve the noise suppression effect during decoding processing, thereby improving the signal-to-noise ratio and improving the laser The long-distance measurement capability of the radar.

In an optional implementation manner, according to the inverse matrix of the coding matrix, the echo signals of N pulse sequences are decoded to obtain the echo signals of the single pulse signal, including: according to the inverse matrix of the coding matrix and N pulses A sequence of echo signals, determining the echo signals of N single pulse signals; performing time delay correction on the echo signals of the N single pulse signals, and determining an average value of the N time delay corrected echo signals.

In a third aspect, the embodiment of the present application further provides a signal transmitting method. In this method, a pulse sequence is determined according to the first sequence, and the pulse sequence is transmitted one or more times. Among them, the first sequence is determined according to the recursive formula, and the recursive formula is

N is a prime number, n=1,...,(N+1)/2.

It can be seen that in this method, the pulse sequence corresponding to the first sequence is transmitted one or more times.

In an optional implementation, the method further includes: determining (N+1)/2 values {u _n } according to the recursive formula, and then calculating the {u _n }th value in the all-zero sequence with length N Set to 1 to get the first sequence of length N.

In an optional implementation, the absolute value of each element in the first sequence is the amplitude value of each pulse signal in the pulse sequence, one element corresponds to a time window, and the time window is used to send the pulse corresponding to the element Signal.

It can be seen that this method transmits a high-power pulse signal in the time window corresponding to element 1 of the first sequence, and transmits a low-power pulse signal in the time window corresponding to element 0 of the first sequence, that is, in the element 0 of the first sequence No high-power pulse signal is transmitted within the corresponding time window.

In an optional implementation manner, when multiple pulse sequences corresponding to the first sequence are transmitted, the end time of the time window corresponding to the last pulse signal in the first pulse sequence is the same as the first pulse signal in the second pulse sequence The time interval between the start times of the corresponding time windows, which is equal to or greater than the maximum round trip time. The first pulse sequence and the second pulse sequence are pulse sequences transmitted twice adjacently. The maximum round-trip time is the maximum value of the round-trip time between a pulse signal and the measurement object.

It can be seen that the time interval between two adjacent transmitted pulse sequences is equal to or greater than the maximum round-trip time between a pulse signal and the measured object.

In a fourth aspect, the embodiment of the present application further provides a signal processing method. In the method, the echo signals of one or more pulse sequences are received; according to the inverse matrix of the coding matrix, the echo signals of one or more pulse sequences are decoded to obtain the echo signals of a single pulse signal. Wherein, the single pulse signal is a pulse signal in one or more pulse sequences. The encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is smaller than a first preset value. N is an integer greater than or equal to 2.

It can be seen that the method decodes the echo signals of one or more pulse sequences according to the inverse matrix of the coding matrix. The reversibility of the coding matrix makes it possible to avoid the influence of side lobes when decoding the echo signal according to the inverse matrix of the coding matrix, thereby improving the long-distance measurement capability of the laser radar. In addition, the difference between the absolute value of each element in the inverse matrix of the coding matrix and 2/(N+1) is smaller than the first preset value, which can improve the noise suppression effect during decoding processing, thereby improving the signal-to-noise ratio and improving the laser The long-distance measurement capability of the radar.

In an optional implementation manner, the method further includes: sequentially shifting the first sequence to the right 1 to (N-1) times to obtain (N-1) second sequences, and then combining the first sequence and (N-1) second sequences are combined to obtain an N-order coding matrix. Among them, the first sequence is obtained according to the recursive formula, and the recursive formula is

N is a prime number, n=1,...,(N+1)/2.

In an optional implementation manner, according to the inverse matrix of the encoding matrix, the echo signal of a pulse sequence is decoded to obtain the echo signal of the single pulse signal, including: dividing the echo signal into N equal parts wave signal; determine the echo signals of N single pulse signals according to the N equally divided echo signals and the inverse matrix of the encoding matrix.

In another optional implementation manner, according to the inverse matrix of the encoding matrix, the echo signals of multiple pulse sequences are decoded to obtain the echo signals of the single pulse signal, including: determining the multiple echo signals according to the multiple echo signals The average value of echo signals; the average value of multiple echo signals is divided into N equally divided echo signals; according to the N equally divided echo signals and the inverse matrix of the encoding matrix, determine the echo of N single pulse signals wave signal.

In a fifth aspect, the present application further provides a signal transmitting device. The signal transmitting device can realize part or all of the functions described in the first aspect or the third aspect. For example, the function of the signal transmitting device may have the functions of some or all of the embodiments described in the first aspect of the present application, and may also have the function of independently implementing any one of the embodiments of the present application. The functions described above may be implemented by hardware, or may be implemented by executing corresponding software on the hardware. The hardware or software includes one or more units or modules corresponding to the above functions.

In a possible design, the structure of the signal transmitting device may include a processing unit and a transmitting unit, and the processing unit is configured to support the signal transmitting device to perform corresponding functions in the foregoing method. The transmitting unit is used to support the transmission of signals. The signal transmitting device may further include a storage unit, which is used to be coupled with the processing unit and the transmitting unit, and stores necessary program instructions and data of the signal transmitting device.

In one embodiment, the signal transmitting device includes:

The processing unit is used to determine N pulse sequences according to the encoding matrix; the encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) less than the first preset value; each pulse sequence corresponds to each row of the encoding matrix; the N is an integer greater than or equal to 2;

A transmitting unit, configured to transmit the N pulse sequences.

In addition, in this aspect, for other optional implementation manners of the signal transmitting device, reference may be made to the relevant content of the above-mentioned first aspect, which will not be described in detail here.

In another embodiment, the signal transmitting device includes:

The processing unit is configured to determine the pulse sequence according to the first sequence, the first sequence is determined according to a recursive formula, and the recursive formula is

N is a prime number, n=1,...,(N+1)/2;

A transmitting unit, configured to transmit the pulse sequence one or more times.

In addition, in this aspect, for other optional implementation manners of the signal transmitting device, reference may be made to the relevant content of the above-mentioned third aspect, which will not be described in detail here.

As examples, the transmission unit may be a transmitter, the storage unit may be a memory, and the processing unit may be a processor.

In one embodiment, the signal transmitting device includes:

A processor, configured to determine N pulse sequences according to the encoding matrix; the encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) less than the first preset value; each pulse sequence corresponds to each row of the encoding matrix; the N is an integer greater than or equal to 2;

A transmitter, configured to transmit the N pulse sequences.

In another embodiment, the signal transmitting device includes:

a processor, configured to determine the pulse sequence according to the first sequence, the first sequence is determined according to a recursive formula, and the recursive formula is

N is a prime number, n=1,...,(N+1)/2;

a transmitter for transmitting the pulse sequence one or more times.

In another embodiment, the signal transmitting device is a chip or a chip system. The processing unit may also be embodied as a processing circuit or a logic circuit; the transmitting unit may be an input/output interface, interface circuit, output circuit, input circuit, pin or related circuit on the chip or chip system.

During implementation, the processor may be used to perform, for example but not limited to, baseband related processing, and the transceiver may be used to perform, for example but not limited to, radio frequency transceiving. The above-mentioned devices may be respectively arranged on independent chips, or at least partly or all of them may be arranged on the same chip. For example, processors can be further divided into analog baseband processors and digital baseband processors. Wherein, the analog baseband processor can be integrated with the transceiver on the same chip, and the digital baseband processor can be set on an independent chip. With the continuous development of integrated circuit technology, more and more devices can be integrated on the same chip. For example, a digital baseband processor can be integrated with various application processors (such as but not limited to graphics processors, multimedia processors, etc.) on the same chip. Such a chip can be called a system chip (System on a Chip, SoC). Whether each device is independently arranged on different chips or integrated and arranged on one or more chips often depends on the needs of product design. The embodiments of the present application do not limit the implementation forms of the foregoing devices.

In a sixth aspect, the present application further provides a signal processing device. The signal processing device can realize part or all of the functions described in the second aspect or the fourth aspect. For example, the function of the signal processing device may have the functions of some or all of the embodiments described in the second aspect of the present application, or may have the function of independently implementing any one of the embodiments of the present application. The functions described above may be implemented by hardware, or may be implemented by executing corresponding software on the hardware. The hardware or software includes one or more units or modules corresponding to the above functions.

In a possible design, the structure of the signal processing device may include a processing unit and a receiving unit, and the processing unit is configured to support the signal transmitting device to perform corresponding functions in the foregoing method. The receiving unit is used to support signal reception. The signal processing device may further include a storage unit for coupling with the processing unit and the receiving unit, which stores necessary program instructions and data of the signal processing device.

In one embodiment, the signal processing device includes:

a receiving unit, configured to receive echo signals of N pulse sequences;

A processing unit, configured to decode and process the echo signals of the N pulse sequences according to the inverse matrix of the coding matrix, to obtain the echo signal of a single pulse signal;

The single pulse signal is a pulse signal in the N pulse sequences; the encoding matrix is an N-order reversible matrix, and the absolute value of each element in the inverse matrix of the encoding matrix is equal to 2/(N+1 ) is less than the first preset value; the N is an integer greater than or equal to 2.

In addition, in this aspect, for other optional implementation manners of the signal processing device, reference may be made to the relevant content of the above-mentioned second aspect, which will not be described in detail here.

In another embodiment, the signal processing device includes:

a receiving unit, configured to receive echo signals of one or more pulse sequences;

The processing unit is configured to decode the echo signals of one or more pulse sequences according to the inverse matrix of the encoding matrix, and obtain the echo signal of a single pulse signal.

In addition, in this aspect, for other optional implementation manners of the signal processing device, reference may be made to the relevant content of the fourth aspect above, which will not be described in detail here.

As an example, the receiving unit may be a receiver, the storage unit may be a memory, and the processing unit may be a processor.

In one embodiment, the signal transmitting device includes:

a receiver, configured to receive echo signals of N pulse sequences;

A processor, configured to decode and process the echo signals of the N pulse sequences according to the inverse matrix of the encoding matrix, to obtain the echo signal of a single pulse signal;

The single pulse signal is a pulse signal in the N pulse sequences; the encoding matrix is an N-order reversible matrix, and the absolute value of each element in the inverse matrix of the encoding matrix is equal to 2/(N+1 ) is less than the first preset value; each pulse sequence corresponds to each row of the encoding matrix; the N is an integer greater than or equal to 2.

In another embodiment, the signal transmitting device includes:

a receiver for receiving echo signals of one or more pulse trains;

The processor is configured to decode the echo signals of one or more pulse sequences according to the inverse matrix of the coding matrix, and obtain the echo signal of the single pulse signal.

In addition, in this aspect, for other optional implementation manners of the signal transmitting device, reference may be made to the related content of the fourth aspect above, which will not be described in detail here.

In another embodiment, the signal transmitting device is a chip or a chip system. The processing unit may also be embodied as a processing circuit or a logic circuit; the receiving unit may be an input/output interface, interface circuit, output circuit, input circuit, pin or related circuit on the chip or chip system.

In the seventh aspect, the embodiment of the present application also provides a computer-readable storage medium, the computer storage medium stores a computer program, and when the computer program is run on the computer, the computer executes the computer according to the first aspect or the first aspect. The method described in the various implementation manners of the second aspect, or make the computer execute the method as described in the second aspect or the various implementation manners of the second aspect, so that the computer executes the third aspect or the various implementation manners of the third aspect The method described above enables the computer to execute the method described in the fourth aspect or various implementation manners of the fourth aspect.

In the eighth aspect, the embodiment of the present application further provides a computer program product, the computer program product includes a computer program, and when the computer program is run on a computer, the computer is made to perform various functions according to the first aspect or the first aspect. The method described in the implementation manner, or causing the computer to execute the method described in the second aspect or various implementation manners of the second aspect, so that the computer executes the method described in the third aspect or various implementation manners of the third aspect A method, so that the computer executes the method described in the fourth aspect or various implementation manners of the fourth aspect.

In the ninth aspect, the embodiment of the present application provides a chip, the chip includes a processor and an interface, the processor is used to call and execute instructions from the interface, and when the processor executes the instructions, the chip executes the following steps: One aspect or the method described in various implementation manners of the first aspect, or causing the computer to execute the method as described in the second aspect or various implementation manners of the second aspect, so that the computer executes the method as described in the third aspect or the third aspect The method described in various implementation manners of the fourth aspect, so that the computer executes the method described in the fourth aspect or various implementation manners of the fourth aspect.

In a tenth aspect, the embodiment of the present application provides a lidar, the lidar includes the device described in the fifth aspect above, or includes the device described in the sixth aspect above.

In the eleventh aspect, the embodiment of the present application provides a terminal device, the terminal device includes the device described in the fifth aspect above, or includes the device described in the sixth aspect above, or includes the device described in the seventh aspect above The computer-readable storage medium may include the computer program product described in the eighth aspect above, or include the chip described in the ninth aspect above, or include the lidar described in the tenth aspect above.

Description of drawings

FIG. 1 is a schematic diagram of a laser radar ranging scene provided by an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a lidar provided in an embodiment of the present application;

FIG. 3 is a schematic diagram of an application scenario provided by an embodiment of the present application;

Fig. 4 is a schematic diagram of another application scenario provided by the embodiment of the present application;

FIG. 5 is a schematic flowchart of a signal transmission method provided by an embodiment of the present application;

Fig. 6 is a schematic diagram of a pulse sequence provided by the embodiment of the present application;

FIG. 7 is a schematic flowchart of a signal processing method provided in an embodiment of the present application;

Fig. 8 is a schematic structural diagram of a laser transceiver provided by an embodiment of the present application;

FIG. 9 is a schematic diagram of an autocorrelation characteristic of a Barker code provided in an embodiment of the present application;

FIG. 10 is a schematic flowchart of another signal processing method provided by the embodiment of the present application;

Fig. 11 is a schematic diagram of an echo signal provided by an embodiment of the present application;

Fig. 12 is a schematic diagram of a signal-to-noise ratio gain provided by an embodiment of the present application;

Fig. 13 is a schematic structural diagram of a signal transmitting device provided by an embodiment of the present application;

Fig. 14 is a schematic structural diagram of a signal processing device provided by an embodiment of the present application;

Fig. 15 is a schematic structural diagram of another signal transmitting device provided by an embodiment of the present application;

Fig. 16 is a schematic structural diagram of another signal processing device provided by an embodiment of the present application;

Fig. 17 is a schematic structural diagram of a device provided by an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

First, in order to better understand the signal transmission and processing methods disclosed in the embodiments of the present application, the laser radar ranging scene applicable to the embodiments of the present application is described.

1. LiDAR ranging scene.

Please refer to FIG. 1 . FIG. 1 is a schematic diagram of a lidar ranging scene 100 provided in an embodiment of the present application. The lidar ranging scene 100 includes a lidar 101 and a measuring object 102 . The laser radar 101 is an abbreviation of light laser detection and ranging (LiDAR), and is used for measuring the distance of the measurement object 102 .

As shown in FIG. 2 , the lidar includes a driving circuit 2011 , a signal transmitter 2012 , a signal receiver 2013 , and a control circuit 2014 . Wherein, the driving circuit 2011 is used for generating electrical signals according to the encoding matrix/sequence, and sending the electrical signals to the signal transmitter 2012 through the interface. The signal transmitter 2012 is used to convert the electrical signal into an optical pulse signal (pulse sequence), and transmit the optical pulse signal to the measuring object 102 . The signal receiver 2013 is used for receiving the echo signal of the light pulse signal reflected by the measurement object 102 and sending the echo signal to the control circuit 2014 . The control circuit 2014 is used to perform decoding processing and the like on the received echo signal.

Wherein, the signal transmitter is a laser, and the laser can be a vertical cavity surface emitting laser (VCSEL), a main oscillator power amplifier (MOPA), and so on. The signal receiver may be a single photon avalanche detector (SPAD) or the like.

In the embodiment of the present application, the driving circuit generates an electrical signal according to the coding matrix, and sends the electrical signal to the signal transmitter through the interface. The signal transmitter receives the electrical signal, converts the electrical signal into N pulse sequences, and transmits the N pulse sequences. The signal receiver receives the echo signals of N pulse sequences reflected by the measuring object, and sends the echo signals of N pulse sequences to the control circuit through the interface. Therefore, the control circuit decodes the echo signals of the N pulse sequences according to the inverse matrix of the coding matrix, and obtains the echo signal of a single pulse signal in the N pulse sequences. Among them, the encoding matrix is a reversible matrix. When decoding the received echo signal according to the inverse matrix of the encoding matrix, the pulse compression is not realized through the cross-correlation operation, but the linear combination operation of the encoding matrix is used to realize the pulse compression, so as to avoid sidelobe effects. In addition, the difference between the absolute value of each element in the inverse matrix of the coding matrix and 2/(N+1) is smaller than the first preset value, which can improve the noise suppression effect during decoding processing, thereby improving the signal-to-noise ratio and improving the laser The long-distance measurement capability of the radar.

In the embodiment of the present application, the lidar can be installed in terminal devices such as unmanned vehicles, unmanned aerial vehicles, unmanned aerial ships, and medical devices.

As shown in FIG. 3 , the embodiment of the present application can be applied to an advanced driver assistance system (advanced driver assistance system, ADAS), and can be used as a link among multiple sensors of the ADAS. The embodiments of the present application can also be applied to other application scenarios that require accurate ranging, accurate space modeling, etc., and have high requirements on device stability, channel isolation, and the like. For example, as shown in FIG. 4 , the embodiments of the present application may be applied to surveying and mapping and remote sensing technologies based on airborne LiDAR or vehicle-mounted LiDAR.

In the ADAS of the third level (L3) and above, the highly reliable long-distance and high-precision measurement of the external environment is usually done through LiDAR. The current laser radar uses time of flight (ToF) technology to achieve accurate ranging, that is, the laser radar emits high-power ultra-short optical pulses, and according to the distance between the receiving time and the emitting time of the echo signal after the optical pulse is reflected by the object The distance between them is used for distance measurement. The measurement distance of ToF technology depends on the pulse power, and the ranging accuracy depends on the pulse width. Due to the limitations of current laser technology and material properties, it is difficult to further increase the pulse peak power and reduce the pulse width.

In order to improve the signal-to-noise ratio, coding technology is also introduced into the ranging of lidar. For example, lidar uses Barker codes or random binary sequences to encode electrical signals, generates encoded optical pulse signals, and transmits the optical pulse signals. However, when lidar uses Barker code or random binary sequence for corresponding decoding, in order to realize pulse compression, the cross-correlation operation will be performed on the received echo signal, and the side lobe effect of Barker code or random binary sequence is obvious and usually difficult to suppress. For example, the sidelobe suppression ratio of the Barker code is 13, and the code length is only 13, so the room for improvement is limited; the sidelobe suppression ratio of the random binary sequence is proportional to the square root of the code length, so the sidelobe influence is obvious and difficult to suppress. Therefore, the improvement of LiDAR's long-distance measurement capability is still limited.

An embodiment of the present application provides a signal transmitting method 100 . In the signal transmitting method 100, N pulse sequences are determined according to the coding matrix, and the N pulse sequences are transmitted. Wherein, the encoding matrix of the N pulse sequences is determined to be an N-order reversible matrix, which is beneficial to avoid side lobe effects when the echo signal is subsequently decoded according to the inverse matrix of the encoding matrix. In addition, the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is smaller than the first preset value, which is beneficial to improving the noise suppression effect during decoding processing and improving the long-distance measurement of the laser radar ability.

The embodiment of the present application also provides a signal processing method 200 . In the signal processing method 200, the echo signals of N pulse sequences are received, and the echo signals of the N pulse sequences are decoded according to the inverse matrix of the encoding matrix to obtain the echo signals of a single pulse signal. Wherein, the single pulse signal is one pulse signal in N pulse sequences, and N is an integer greater than or equal to 2. The encoding matrix used when decoding the received echo signal is the encoding matrix in the above S101, that is, the encoding matrix is an invertible matrix, and the absolute value of each element in the inverse matrix of the encoding matrix is the same as 2/(N+1 ) is smaller than the first preset value, thereby avoiding side lobe effects during decoding processing, and improving noise suppression effects during decoding processing, thereby improving the long-distance measurement capability of the laser radar.

The embodiment of the present application also provides a signal processing method 300 . In the signal processing method 300, a pulse sequence is determined according to the first sequence, and the pulse sequence is transmitted one or more times. The echo signals of one or more pulse sequences are received, and the echo signals of one or more pulse sequences are decoded according to the inverse matrix of the coding matrix to obtain the echo signals of a single pulse signal. Among them, the first sequence is determined according to the recursive formula, and the recursive formula is

n=1,...,(N+1)/2, where N is a prime number. A monopulse signal is one pulse signal in a train of one or more pulses. The encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is smaller than the first preset value, and N is an integer greater than or equal to 2. In this way, sidelobe effects during decoding processing can also be avoided, and the noise suppression effect during decoding processing can be improved, thereby improving the signal-to-noise ratio and improving the long-distance measurement capability of the laser radar.

The signal transmitting method and the signal processing method provided in the embodiments of the present application may be executed by a laser radar or components inside the laser radar, or may also be executed by other transmitting devices.

2. Signal transmission method 100 .

An embodiment of the present application provides a signal transmitting method 100 . FIG. 5 is a schematic flowchart of the signal transmitting method 100 . The signal transmission method 100 includes but not limited to the following steps:

S101. Determine N pulse sequences according to the encoding matrix, the encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is less than the first preset value, Each pulse sequence corresponds to each row of the encoding matrix, and N is an integer greater than or equal to 2.

Understandably, an electrical signal is generated according to the encoding matrix, and then the electrical signal is converted into N pulse sequences (that is, optical pulse signals).

Wherein, the first preset value is a preset threshold, and the threshold can be set according to the effect of noise suppression. For example, the first preset value may be 0, 0.001, 0.01, 0.1, etc. The embodiment of the present application does not limit the value of the first preset value. Therefore, the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is less than the first preset value, which means that the absolute value of each element in the inverse matrix of the encoding matrix approaches 2 /(N+1), which is beneficial to improve the noise suppression effect when the echo signal is decoded according to the inverse matrix of the coding matrix, which in turn is beneficial to improve the long-distance measurement capability of the laser radar.

In addition, each pulse sequence corresponds to each row of the encoding matrix, so that N rows of the encoding matrix correspond to N pulse sequences. The absolute value of each element in a row of the encoding matrix is the amplitude value of each pulse signal in the corresponding pulse. That is to say, element 1 in each row of the encoding matrix represents a high-power pulse signal, element 0 represents no high-power pulse signal, and a pulse sequence includes multiple pulse signals.

In an optional implementation manner, before determining the N pulse sequences according to the coding matrix, an N-order coding matrix is also determined according to the first matrix. Any two rows of the first matrix are orthogonal to each other, and the product of the first matrix and the transpose of the first matrix is an identity matrix. The first matrix is a Hadamard matrix of order N+1.

Understandably, determining the N-order encoding matrix according to the first matrix includes: deleting the first row and the first column of the first matrix to obtain the second matrix, and then replacing the element 1 in the second matrix with 0, and replacing the first element with 1 The element -1 in the second matrix obtains the N-order encoding matrix. The encoding matrix obtained according to the first matrix and the rule has reversibility, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is smaller than the first preset value.

For example, the first matrix is Hadamard matrix H of order 4:

Delete the first row and first column of the Hadamard matrix H, and the obtained second matrix H' is:

Then replace the element 1 in the second matrix H' with 0, replace the element -1 in the second matrix H' with 1, and obtain the coding matrix C as:

Then, the invertible matrix C' of the encoding matrix C is:

It can be seen that the coding matrix C is a reversible matrix, and the absolute value of each element in the reversible matrix C' of the coding matrix C is equal to 2/(N+1), that is, 0.5, which is the absolute value of each element in C' of the reversible matrix The difference with 2/(N+1) is less than a first preset value, and the first preset value is 0.

It can be understood that the reversibility of the encoding matrix is beneficial to avoid side lobe effects when subsequent decoding processing is performed according to the inverse matrix of the encoding matrix; the absolute value of each element in the inverse matrix of the encoding matrix is related to 2/(N+1) The difference is less than the first preset value, which is beneficial to improve the noise suppression effect during the decoding process when the encoding matrix is subsequently decoded according to the inverse matrix of the encoding matrix, thereby improving the signal-to-noise ratio and improving the long-distance measurement of the laser radar ability.

S102. Transmit N pulse sequences.

Understandably, an element of the encoding matrix corresponds to a time window, and the time window is used to send the pulse signal corresponding to the element. That is, the pulse signal corresponding to each element is transmitted sequentially within the time window corresponding to each element in each row of the encoding matrix. Since element 1 in each row of the coding matrix represents a high-power pulse signal, and element 0 represents no high-power pulse signal, the high-power pulse signal is sequentially transmitted in the time window corresponding to element 1 in each row of the coding matrix to realize the N The emission of the pulse train.

For example, Fig. 6 is a pulse sequence determined according to the encoding matrix of formula (3). It can be seen that the three rows of the encoding matrix correspond to three pulse sequences (pulse sequence 1 - pulse sequence 3). Element 1 in each row represents a high-power pulse signal, and element 0 represents no high-power pulse signal. Therefore, each pulse sequence includes 2 high-power pulse signals and 1 non-high-power pulse signal. Each row of the matrix corresponds to three time windows, which are used to transmit a pulse sequence. Therefore, the high-power pulse signal is sequentially sent in the time window corresponding to element 1 in each row of the encoding matrix, and the high-power pulse signal is not sent in the time window corresponding to element 0 in each row.

In an optional implementation manner, the width of each pulse signal is the same, that is, the duty cycle of each high-power pulse signal and each non-high-power pulse signal is the same. The intervals between the pulse signals included in each pulse sequence are also the same, that is, the intervals between each pulse signal are the same. The embodiment of the present application does not limit the interval value between each pulse signal. Optionally, in order to consider factors such as dead zone, round-trip time, and laser performance, the interval between each pulse signal can be set as short as possible, for example, the interval between each pulse is set to 0.

In an optional implementation manner, the time between the end time of the time window corresponding to the last pulse signal in the first pulse sequence and the start time of the time window corresponding to the first pulse signal in the second pulse sequence Interval, equal to or greater than the maximum round-trip time. The first pulse sequence and the second pulse sequence are respectively pulse sequences corresponding to two adjacent rows in the encoding matrix. The maximum round-trip time is the maximum value of the round-trip time between a pulse signal and the measurement object, and the pulse signal is a high-power pulse signal. Therefore, the time interval between every two pulse sequences transmitted by the signal transmitter is equal to or greater than the maximum round-trip time between a high-power pulse signal and the measured object.

For example, the pulse waveform generated by the lidar according to the coding matrix is shown in FIG. 6 above. Then after the lidar transmits the high-power pulse signal in the time window corresponding to the second element 1 in the first row of the coding matrix, when the interval is equal to or greater than the maximum round-trip time between a high-power pulse signal and the measured object, in The high-power pulse signal is not transmitted in the time window corresponding to element 0 in the second row of the encoding matrix, and two high-power pulse signals are transmitted in the two time windows corresponding to the two elements 1 in the second row in turn, and then the interval is equal to or When it is greater than the maximum value of the round-trip time between a high-power pulse signal and the measured object, two high-power pulse signals are sequentially transmitted in the two time windows corresponding to the two elements 1 in the third row of the encoding matrix, and not in the third A high-power pulse signal is transmitted within the time window corresponding to element 0 of the row.

In the embodiment of the present application, N pulse sequences are determined and transmitted according to the encoding matrix. The reversibility of the encoding matrix is beneficial to decode the echo signal according to the inverse matrix of the encoding matrix. Instead of realizing pulse compression through cross-correlation operations, linear combination operations are used to achieve pulse compression, thereby avoiding side lobe effects and improving laser performance. The long-distance measurement capability of the radar. In addition, the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is smaller than the first preset value, which is also beneficial to improve the noise suppression effect during decoding processing, thereby improving the signal-to-noise ratio, Improve the long-distance measurement capability of lidar.

3. Signal processing method 200 .

The embodiment of the present application also provides a signal processing method 2 . FIG. 7 is a schematic flowchart of the signal processing method 200 . The signal processing method 200 includes but not limited to the following steps:

S201. Receive echo signals of N pulse sequences, where N is an integer greater than or equal to 2.

It can be understood that an echo signal is an echo signal of a pulse sequence reflected by the measured object. In the above S102, N pulse sequences are transmitted, so the echo signals of the N pulse sequences are received.

S202. According to the inverse matrix of the encoding matrix, the echo signals of N pulse sequences are decoded to obtain the echo signals of the single pulse signal. The encoding matrix is an N-order reversible matrix, and the inverse matrix of the encoding matrix is the The difference between the absolute value and 2/(N+1) is smaller than the first preset value.

It can be understood that the encoding matrix is the encoding matrix determined in the above S101, that is, the encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is less than the first a default value.

In an optional implementation manner, the echo signal is decoded according to the inverse matrix of the coding matrix to obtain the echo signal of the single pulse signal, including: the echo signal according to the inverse matrix of the coding matrix and N pulse sequences , determining the echo signals of the N single pulse signals; performing time delay correction on the echo signals of the N single pulse signals, and determining an average value of the N time delay corrected echo signals.

For example, the waveform of the pulse signal emitted by the lidar is shown in Figure 6 above, assuming that the echo signal of a single pulse signal is x(t), and the time delay of a single pulse signal is τ, then the echo signals of the three pulse sequences are :

Among them, n _i (t) represents the noise of the i-th echo signal. Therefore, the laser radar can determine the echo signals of N single pulse signals according to the inverse matrix of the coding matrix and the echo signals of N pulse sequences:

Wherein, x _i (t) is the echo signal of the monopulse signal with noise. The laser radar modifies the echo signals of the three monopulse signals with time delay, and obtains the echo signals of the three time delay corrected monopulse signals as x ₁ (t), x ₂ (t), x ₃ (t) , and then calculate the average value of x ₁ (t), x ₂ (t), x ₃ (t) to get:

It can be seen that, according to the inverse matrix of the coding matrix, the echo signals of N pulse sequences are decoded to obtain the echo signal of a single pulse signal.

According to formula (7), it can be obtained that when the algorithm of the embodiment of the present application is used for encoding and decoding processing, the standard deviation of signal noise is reduced to 1/2 of that before encoding the pulse signal. The signal transmitter transmits three single-pulse signals, and when the three single-pulse signals are averaged three times during decoding, the noise standard deviation is reduced to that before the pulse signal is encoded.

Therefore, when the embodiment of the present application is adopted, the signal-to-noise ratio gain is about 1.155.

In the embodiment of the present application, the encoding matrix is used for encoding, and after the echo signal is decoded according to the inverse matrix of the encoding matrix, if the echo signal of the single pulse signal is not averaged, the signal power increases by N times, and the noise power increases (2N)/(N+1) times. At this time, the gain of the signal-to-noise ratio is (N+1)/2. When N pulse signals are used for cumulative transmission, the signal power is also increased by N times, but the noise power is increased

times, so the signal-to-noise ratio gain is

times. Therefore, the embodiment of the present application adopts the matrix coding method instead of the scheme of accumulative transmission of multiple pulse signals, which can improve the signal-to-noise ratio by about

For example, if N is equal to 11, the signal-to-noise ratio gain is 6 when multiple pulse signals are transmitted using the encoding matrix scheme, and the signal-to-noise ratio gain is 3.32 when multiple pulse signals are cumulatively transmitted. Then, within the same measurement time, a higher SNR gain can be obtained by adopting the encoding matrix encoding to transmit multiple pulse signals.

In the embodiment of the present application, the echo signals of the N pulse sequences are decoded according to the inverse matrix of the encoding matrix. The reversibility of the coding matrix makes the controller decode the echo signal according to the inverse matrix of the coding matrix, instead of realizing the pulse compression through the cross-correlation operation, it uses the linear combination operation of the coding matrix to realize the pulse compression, thus avoiding the side lobe Influence, improve the long-distance measurement capability of lidar. In addition, the difference between the absolute value of each element in the inverse matrix of the coding matrix and 2/(N+1) is smaller than the first preset value, which can improve the noise suppression effect during decoding processing, thereby improving the signal-to-noise ratio and improving the laser The long-distance measurement capability of the radar.

Fig. 8 is a pulse-coded laser transceiver device when pulse code is used for distance measurement. The pulse-coded laser transceiver includes a coding unit, a laser pulse transmitting unit, and a laser pulse receiving unit. In the pulse coded laser transceiver device, a coding unit based on multiple charging units is used to generate a coded sequence of electric pulses with a large current, and the coded sequence of electric pulses is sent into the laser emitting device. The laser pulse emitting unit thus generates and emits a sequence of coded light pulses. The laser pulse receiving unit receives the reflected echo signal, and the echo signal is analyzed correspondingly by the data processing unit.

In this scheme, a few optical pulse signals are emitted, and effective superposition is not realized, so the signal-to-noise ratio is low. In the embodiment of the present application, a longer pulse sequence is transmitted, and the echo signals of different pulse signals are effectively superimposed during decoding processing, so that the signal-to-noise ratio can be effectively improved. In addition, what is transmitted in this scheme is a pulse sequence that does not have good autocorrelation characteristics, and is easily affected by side lobes. However, in the embodiment of the present application, the transmitted pulse sequence is determined according to the reversible coding matrix, and the echo signal is decoded according to the reversible matrix of the coding matrix, which may not be affected by side lobes.

Fig. 9 is a schematic diagram of the autocorrelation characteristic of the Barker code. As shown in Figure 9, the sidelobe suppression ratio after the autocorrelation operation of the Barker code is 13, and the code length of the Barker code is fixed and is 13, then when the laser radar uses the Barker code for pulse coding, the SNR Improvement is limited. However, in the embodiment of the present application, a reversible coding matrix is used to decode the echo signal, so that no cross-correlation operation is required on the echo signal, which can avoid the influence of side lobes and improve the signal-to-noise ratio.

Compared with the encoding method and decoding method corresponding to Fig. 8 and Fig. 9, when the encoding method and decoding method in the embodiment of the present application are adopted, the influence of side lobes can be avoided, and its dynamicity and robustness will not be disturbed. Therefore, the signal-to-noise ratio can be improved, thereby improving the long-distance measurement capability of the lidar.

The embodiment of the present application determines the pulse sequence according to the encoding matrix with special properties, and transmits multiple pulse signals included in the pulse sequence, which can increase the number of transmitted pulses compared with transmitting only one pulse signal within the same measurement time , which can increase the signal-to-noise ratio gain. In addition, compared with the scheme of multiple cumulatively transmitted pulse signals, the embodiment of the present application transmits multiple pulse signals according to the encoding matrix, changing the original high-power narrow pulses into narrow pulses, which can effectively reduce the demand for peak power.

4. Signal processing method 300 .

The embodiment of the present application also provides a signal processing method 300 , and FIG. 10 is a schematic flowchart of the signal processing method 300 . The signal processing method 300 includes but not limited to the following steps:

S301. Determine the pulse sequence according to the first sequence, the first sequence is determined according to the recursive formula, and the recursive formula is

n=1,...,(N+1)/2, where N is a prime number.

Understandably, the value of N may be determined according to the number of transmitted pulse signals.

In an optional implementation manner, the driver in the lidar generates an electrical signal according to the first sequence, and sends the electrical signal to the signal transmitter in the lidar through an interface. The signal transmitter converts the electrical signal into a train of pulses (optical signal).

It is understandable that (N+1)/2 values {u _n } are determined according to the above recursive formula, n=1,..., (N+1)/2, and then the all-zero sequence of length N Set the {u _n }th value to 1 to obtain the first sequence of length N.

For example, if N is determined to be 7, it is determined according to the above recursive formula that u _n ={0,1,3,6}, then the {u _n }th value in the all-zero sequence with a length of 7 is set to 1 to obtain The first sequence is: {1,1,0,1,0,0,1}.

S302. Transmit the pulse sequence one or more times.

In an optional implementation manner, the signal transmitter in the laser radar transmits one or more pulse sequences.

The absolute value of each element in the first sequence is the amplitude value of each pulse signal in the pulse sequence, one element corresponds to a time window, and the time window is used to send the pulse signal corresponding to the element.

It can be seen that the high-power pulse signal is transmitted in the time window corresponding to element 1 of the first sequence, and the low-power pulse signal is transmitted in the time window corresponding to element 0 of the first sequence, that is, in the time window corresponding to element 0 of the first sequence No high-power pulse signals are emitted within the time window.

In addition, it is assumed that the time interval between two adjacent pulse signals in a pulse sequence is the pulse repetition period, denoted as T. It can be understood that in the embodiment of the present application, the pulse signal is transmitted uniformly, and the time interval refers to the leading edge of one pulse signal to the leading edge of an adjacent pulse signal, the peak value of one pulse signal to the peak value of an adjacent pulse signal, or one The trailing edge of a burst to the trailing edge of an adjacent burst, rather than the leading edge of one burst to the trailing edge of an adjacent burst. The time required for a high-power pulse signal to reach the maximum measurement distance and return to the original path is the maximum flight time, and is recorded as τ. Assuming that the code length of a pulse sequence is N, the minimum period for repeatedly sending the pulse sequence corresponding to the first sequence is N*T.

For example, the first sequence is {1,1,0}, assuming that the designed maximum measurement distance is 300 meters, the maximum flight time of the pulse is 2us. The length of the pulse sequence is 3, so the time interval between every two adjacent pulse signals is 0.6667us. The transmission timing of the pulse signal in the pulse sequence and the corresponding echo signal are shown in FIG. 11 .

S303. Receive echo signals of one or more pulse sequences.

In an optional implementation manner, the signal receiver in the lidar receives echo signals of one or more pulse sequences. When the above laser radar transmits a pulse sequence, the laser radar receives the echo signal of one pulse sequence; when the above laser radar transmits multiple pulse sequences, the laser radar receives the echo signals of multiple pulse sequences.

Optionally, the echo signals of the one or more pulse sequences are sent to the control circuit through an interface.

S304. Decode the echo signals of one or more pulse sequences according to the inverse matrix of the encoding matrix to obtain the echo signals of a single pulse signal. The single pulse signal is a pulse signal in one or more pulse sequences, and the encoding matrix It is an N-order invertible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is smaller than a first preset value, and N is an integer greater than or equal to 2.

In an optional implementation manner, the control circuit in the laser radar decodes the echo signals of one or more pulse sequences according to the inverse matrix of the coding matrix, and obtains the echo signals of the single pulse signal.

In an optional implementation manner, the coding matrix is determined according to the first sequence in S401 above. Understandably, the first sequence is cyclically shifted to the right by 1 to (N-1) times to obtain (N-1) second sequences, and then the first sequence and (N-1) second sequences are combined , to obtain the N-order encoding matrix.

For example, as described in S301 above, the first sequence is: {1,1,0,1,0,0,1}. Then the encoding matrix C obtained according to the first sequence and the invertible matrix of the encoding matrix C are C' as:

It can be seen that the encoding matrix C determined according to the above first sequence is a reversible matrix, and the absolute value of each element in C' of the reversible matrix is equal to 2/(7+1), ie 0.25. At this time, the difference between the absolute value of each element in C' of the reversible matrix and 2/(N+1) is smaller than the first preset value, and the first preset value is 0.

In an optional implementation manner, when the received echo signal is an echo signal of a pulse sequence, the echo signal of a pulse sequence is decoded to obtain an echo signal of a single pulse signal, including: The signal is divided into N equally divided echo signals; according to the N equally divided echo signals and the inverse matrix of the coding matrix, the echo signals of N single pulse signals are determined.

In another optional implementation manner, when the received echo signal is an echo signal of N pulse sequences, the transmitted pulse sequence is periodic, and the received echo signal is also periodic. Therefore, the echo signal to be measured can be selected from the echo signal according to the periodicity. Therefore, according to the inverse matrix of the encoding matrix, the echo signals of multiple pulse sequences are decoded to obtain the echo signal of the single pulse signal, including: determining the average value of the multiple echo signals according to the multiple echo signals; The average value of the echo signals is divided into N equally divided echo signals; according to the N equally divided echo signals and the inverse matrix of the encoding matrix, the echo signals of the N single pulse signals are determined.

That is to say, the mean value of the N echo signals is calculated, and the mean value is divided into N equal parts, and then the echo signals of the N single pulse signals are determined according to the inverse matrix of the encoding matrix and the N equal parts.

For example, if the laser radar transmits the pulse sequence corresponding to the first sequence k times, then the laser radar receives k echo signals. The lidar calculates the mean value of k echo signals as x(t), and then divides x(t) into N segments, then the expression of each segment is:

x _k (t)=x(t-Δl*k),t∈[Δl*(k-1),Δl*k] (10)

Assuming that the echo signal of the cyclic sequence received by the lidar is y(t), and y(t) is divided into N terminals, then the expression of each segment is:

y _k (t)=y(t-Δl*k),t∈[Δl*(k-1),Δl*k] (11)

Then y _k (t) is obtained by the cyclic delay superposition of x _k (t), namely:

Among them, Code represents the coding matrix, and _nk (t) represents the segmented noise. Therefore, according to the inverse matrix of the coding matrix and the echo signals of N segments, the laser radar determines N single pulse signals as:

It can be seen that the determined monopulse signal is a monopulse signal with noise. In addition, when decoding in this way, the noise of the system is also suppressed, and the suppression efficiency is the same as that in the above-mentioned signal processing method 200 . However, in the above-mentioned signal processing method 200, it is necessary to store N sets of echo signals, but in this method, only one set of echo signals needs to be stored, and the demodulation is realized by performing a linear operation on the set of echo signals, so that the chip can be reduced. storage costs.

In addition, in the above-mentioned signal processing method 200, assuming that the number of sampling points of a single echo signal is M, the storage space requirement is M*N, and the computational complexity is N*N*M. The resource consumption is too high, which is not conducive to the chip. accomplish. For example, if the sampling point frequency of a single echo signal is 400MHz, and the measurement time of the echo signal is 2us, then M=800, assuming that 11-bit encoding is used, the total usage of single-channel buffer control is about 10kb, and the number of multiplication and addition operations About 100k times, the single-channel computing power requirement reaches 5Gop/s. In the signal processing method 400, the first sequence is used instead of the encoding matrix, the storage space requirement is reduced to M, and the computational complexity is reduced to N*N, so the computational complexity, storage space, and power consumption of the chip can be effectively reduced.

Figure 12 provides the signal-to-noise ratio gains corresponding to different code lengths when N is different prime numbers and composite numbers when this method is used for encoding and decoding. It can be seen that when N is a prime number, a relatively stable SNR gain can be obtained; when the code length is 11, the SNR gain reaches above 1.8; when the code length is 19, the SNR gain reaches 2.2. However, when N is a composite number, it is almost impossible to obtain a relatively stable signal-to-noise ratio gain.

In the embodiment of the present application, the pulse sequence is determined according to the first sequence, and the pulse sequence is transmitted one or more times, and then one or more received echo signals are decoded according to the inverse matrix of the coding matrix. The reversibility of the coding matrix can avoid side lobe effects, and the absolute value of each element in the inverse matrix of the coding matrix tends to be equal, so it can improve the noise suppression effect during the decoding process, thereby improving the signal-to-noise ratio and improving the laser The long-distance measurement capability of the radar.

5. Device.

In order to realize the various functions in the method provided by the above-mentioned embodiments of the present application, the lidar may include a hardware structure and/or a software module, and realize the above-mentioned functions in the form of a hardware structure, a software module, or a hardware structure plus a software module. Whether one of the above-mentioned functions is executed in the form of a hardware structure, a software module, or a hardware structure plus a software module depends on the specific application and design constraints of the technical solution.

As shown in FIG. 13 , the embodiment of the present application provides a signal transmitting device 1300 . The signal transmitting device 1300 may be a component of a lidar (for example, an integrated circuit, a chip, etc.). The signal transmitting apparatus 1300 may include: a processing unit 1301 and a transmitting unit 1302 . Optionally, a storage unit 1303 may also be included.

In a possible design, one or more units in Figure 13 may be implemented by one or more processors, or by one or more processors and memory; or by one or more processors and a transmitter; or by one or more processors, memories and a transmitter, which is not limited in this embodiment of the present application. The processor, memory and transmitter can be set separately or integrated.

The signal transmitting device 1300 is capable of implementing the above-mentioned signal transmitting method described in the embodiment of the present application. For example, the signal transmitting device 1300 includes a drive circuit and a module or unit or means (means) corresponding to the signal transmitter executing the steps described in the embodiments of the present application, and the function or unit or means (means) can be implemented by software, or It can be realized by hardware, it can also be realized by executing corresponding software by hardware, and it can also be realized by a combination of software and hardware. For details, further reference may be made to the corresponding descriptions in the aforementioned corresponding method embodiments.

In a possible design, the signal transmitting device 1300 includes:

The processing unit 1301 is configured to determine N pulse sequences according to the encoding matrix; the encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) The value is less than the first preset value; each pulse sequence corresponds to each row of the encoding matrix; the N is an integer greater than or equal to 2;

A transmitting unit 1302, configured to transmit the N pulse sequences.

In an optional implementation manner, before the processing unit 1301 determines the N pulse sequences according to the encoding matrix, it is further configured to: delete the first row and the first column of the first matrix to obtain the second matrix; the first Any two rows of the matrix are mutually orthogonal, and the product between the first matrix and the transposition of the first matrix is an identity matrix; the first matrix is a (N+1) order Hadamard matrix; The element 1 in the second matrix is replaced by 0, and the element -1 in the second matrix is replaced by 1 to obtain an encoding matrix.

In an optional implementation manner, the absolute value of each element in a row of the encoding matrix is the amplitude value of each pulse signal in the corresponding pulse sequence, and one element corresponds to a time window, and the time window is used to send The pulse signal corresponding to this element.

In an optional implementation manner, the time between the end time of the time window corresponding to the last pulse signal in the first pulse sequence and the start time of the time window corresponding to the first pulse signal in the second pulse sequence The interval is equal to or greater than the maximum round-trip time; the first pulse sequence and the second pulse sequence are the pulse sequences corresponding to two adjacent rows in the encoding matrix, and the maximum round-trip time is a pulse signal to the measured object The maximum round-trip time between.

In another possible design, the signal transmitting device 1300 includes:

The processing unit 1301 is configured to determine the pulse sequence according to the first sequence. Among them, the first sequence is determined according to the recursive formula, and the recursive formula is

n=1,...,(N+1)/2, N is a prime number;

The transmitting unit 1302 is configured to transmit the pulse sequence one or more times.

In an optional implementation manner, the processing unit 1301 is further configured to determine (N+1)/2 values {u _n } according to the recursive formula, and then the {u n }th value {u _n } in the length-N all-zero sequence Set the value to 1 to get the first sequence of length N.

The embodiments of the present application and the method embodiments shown above are based on the same idea, and the technical effects brought about by them are also the same. For specific principles, please refer to the description of the above-mentioned embodiments, and details will not be repeated here.

As shown in FIG. 14 , the embodiment of the present application provides a signal processing apparatus 1400 . The signal processing device 1400 may be a component of a lidar (for example, an integrated circuit, a chip, etc.). The signal processing apparatus 1400 may include: a processing unit 1401 and a receiving unit 1402 . Optionally, a storage unit 1403 may also be included.

In a possible design, one or more units in Figure 14 may be implemented by one or more processors, or by one or more processors and memory; or by one or more processors and a transmitter; or by one or more processors, memories and a transmitter, which is not limited in this embodiment of the present application. The processor, memory and transmitter can be set separately or integrated.

The signal processing device 1400 is capable of implementing the above-mentioned signal processing method described in the embodiment of the present application. For example, the signal processing device 1400 includes a signal receiver and a control circuit to execute modules or units or means (means) corresponding to the steps described in the embodiments of this application, and the functions or units or means (means) can be implemented by software, or It can be realized by hardware, it can also be realized by executing corresponding software by hardware, and it can also be realized by a combination of software and hardware. For details, further reference may be made to the corresponding descriptions in the aforementioned corresponding method embodiments.

In a possible design, the signal processing device 1400 includes:

a receiving unit 1402, configured to receive echo signals of N pulse sequences;

The processing unit 1401 is configured to decode and process the echo signals of the N pulse sequences according to the inverse matrix of the coding matrix, and obtain the echo signal of the single pulse signal;

In an optional implementation manner, the processing unit 1401 decodes the echo signals of the N pulse sequences according to the inverse matrix of the encoding matrix to obtain the echo signals of the single pulse signal, specifically for: according to The inverse matrix of the encoding matrix and the echo signals of the N pulse sequences determine the echo signals of the N single pulse signals; perform time delay correction on the echo signals of the N single pulse signals, and determine N The mean value of the echo signal after delay correction.

In another possible design, the signal processing device 1400 includes:

a receiving unit 1402, configured to receive echo signals of one or more pulse sequences;

The processing unit 1401 is configured to decode the echo signals of one or more pulse sequences according to the inverse matrix of the coding matrix, and obtain the echo signal of the single pulse signal,

Wherein, the single pulse signal is a pulse signal in one or more pulse sequences. The encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is smaller than a first preset value. N is an integer greater than or equal to 2.

In an optional implementation manner, the processing unit 1401 is further configured to cyclically shift the first sequence to the right by 1 to (N-1) times to obtain (N-1) second sequences, and then the first sequence Combined with (N-1) second sequences to obtain an N-order coding matrix. Among them, the first sequence is obtained according to the recursive formula, and the recursive formula is

N is a prime number, n=1,...,(N+1)/2.

In an optional implementation manner, the processing unit 1401 decodes an echo signal of a pulse sequence according to the inverse matrix of the encoding matrix to obtain an echo signal of a single pulse signal, specifically for: dividing the echo signal into N equally divided echo signals; according to the N equally divided echo signals and the inverse matrix of the encoding matrix, the echo signals of N single pulse signals are determined.

In another optional implementation manner, the processing unit 1401 decodes echo signals of multiple pulse sequences according to the inverse matrix of the encoding matrix to obtain echo signals of a single pulse signal, specifically for: Echo signal, determine the average value of multiple echo signals; divide the average value of multiple echo signals into N equally divided echo signals; according to the N equally divided echo signals and the inverse matrix of the encoding matrix, determine N The echo signal of the monopulse signal.

FIG. 15 is a schematic diagram of another possible structure of a signal transmitting apparatus 1300 provided by an embodiment of the present application. The signal transmitting apparatus 1500 may include at least one processor 1501 and a transmitter 1502 . Their functions may respectively correspond to the specific functions of the processing unit 1301 and the transmitting unit 1302 shown in FIG. 13 , which will not be repeated here. Optionally, the signal transmitting device 1500 may further include a memory 1503 for storing program instructions and/or data for reading by the processor 1501 .

FIG. 16 is a schematic diagram of another possible structure of a signal processing apparatus 1400 provided by an embodiment of the present application. The signal processing device 1600 may include at least one processor 1601 and a receiver 1602 . Their functions may respectively correspond to the specific functions of the processing unit 1401 and the receiving unit 1402 shown in FIG. 14 , which will not be repeated here. Optionally, the signal processing device 1600 may further include a memory 1603 for storing program instructions and/or data for reading by the processor 1601 .

FIG. 17 is a schematic structural diagram of a device 1700 provided in an embodiment of the present application. The device 1700 shown in FIG. 17 may be the signal transmitting device itself, or may be a chip or a circuit capable of completing the functions of the signal transmitting device, for example, the chip or circuit may be set in the signal transmitting device. The apparatus 1700 shown in FIG. 17 may include at least one processor 1701 (for example, the processing module may be implemented by the processor 1701 ) and an interface circuit 1702 . The processor 1701 implements the steps involved in the method provided by the embodiment of the present application. Optionally, the apparatus 1700 may further include a memory 1703, and the memory 1703 may be used to store instructions. The processor 1701 executes the instructions stored in the memory 1703, so that the apparatus 1700 implements the steps in the methods provided in the foregoing embodiments.

Further, the processor 1701, the interface circuit 1702, and the memory 1703 may communicate with each other through an internal connection path, and transfer control and/or data signals. The memory 1703 is used to store a computer program, and the processor 1701 can call and run the computer program from the memory 1703 to control the interface circuit 1702 to receive or send a signal, or the processor 1701 can call and run the computer program from the memory 1703 through the interface circuit 1702 A computer program to complete the steps performed by the signal transmitting device or the signal processing device in the method provided by the embodiment of the present application. The memory 1703 may be integrated in the processor 1701 , or may be set separately from the processor 1701 .

Optionally, if the apparatus 1700 is a device, the interface circuit 1702 may include a receiver and a transmitter. Wherein, the receiver and the transmitter may be the same component or different components. When the receiver and transmitter are the same component, the component may be referred to as a transceiver.

Optionally, if the device 1700 is a chip or a circuit, the interface circuit 1702 may include an input interface and an output interface, and the input interface and the output interface may be the same interface, or may be different interfaces respectively.

Optionally, if the device 1700 is a chip or a circuit, the device 1700 may not include a memory 1703, and the processor 1701 may read instructions (programs or codes) in the memory outside the chip or circuit to implement the functions provided by the embodiments of the present application. The steps performed by the signal transmitting device or the signal processing device in the method.

Optionally, if the device 1700 is a chip or a circuit, the device 1700 may include resistors, capacitors or other corresponding functional components, and the processor 1701 or the interface circuit 1702 may be implemented by corresponding functional components.

As an implementation manner, the function of the interface circuit 1702 may be realized by a transceiver circuit or a dedicated transceiver chip. The processor 1701 may be realized by a dedicated processing chip, a processing circuit, a processor or a general-purpose chip.

As another implementation manner, it may be considered to use a general-purpose computer to implement the first device provided in the embodiment of the present application. That is, program codes for realizing the functions of the processor 1701 and the interface circuit 1702 are stored in the memory 1703 , and the processor 1701 realizes the functions of the processor 1701 and the interface circuit 1702 by executing the program codes stored in the memory 1703 .

Wherein, the functions and actions of each module or unit in the device 1700 listed above are only exemplary descriptions, and each functional unit in the device 1700 can be used to perform each action or process performed by the signal transmitting device or the signal processing device in the embodiment of the present application process. In order to avoid redundant descriptions, detailed descriptions thereof are omitted here.

The embodiment of the present application also provides a laser radar, which is used to provide a ranging function for a measurement object. It includes at least one signal transmitting device and signal processing device mentioned in the above-mentioned embodiments of the present application. The signal transmitting device and signal processing device in the laser radar can be integrated into a complete machine or equipment, or the signal transmitting device in the laser radar The and signal processing means can also be provided independently as elements or means.

The embodiment of the present application also provides a terminal device, and the terminal device may be a terminal device such as an unmanned vehicle, an unmanned aerial vehicle, an unmanned aerial ship, or a medical device. The terminal device includes the above-mentioned signal transmitting device 1300, or the above-mentioned signal processing device 1400, or the above-mentioned signal transmitting device 1500, or the above-mentioned signal processing device 1600, or the above-mentioned device 1700, or the above-mentioned laser radar.

In yet another optional manner, when software is used to implement the signal transmitting device or the signal processing device, it may be fully or partially implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the processes or functions described in the embodiments of the present application are realized in whole or in part. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website, computer, server or data center Transmission to another website site, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer, or a data storage device such as a server or a data center integrated with one or more available media. The available medium may be a magnetic medium (such as a floppy disk, a hard disk, or a magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (solid state disk, SSD)), etc.

It should be noted that the processor included in the above-mentioned signal transmitting device or signal processing device for executing the communication method provided by the embodiment of the present application may be one or more processors, and the one or more processors may be Central processing unit (central processing unit, CPU), general-purpose processor, digital signal processor (digital signal processor, DSP), application-specific integrated circuit (application-specific integrated circuit, ASIC), field programmable gate array (field programmable gate array) , FPGA) or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various illustrative logical blocks, modules and circuits described in connection with the present disclosure. The processor may also be a combination of computing functions, for example, a combination of one or more microprocessors, a combination of DSP and a microprocessor, and so on. Alternatively, if the first detecting device is a processing device, then the processing device may be a CPU, a general purpose processor, DSP, ASIC, FPGA or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It can implement or execute the various illustrative logical blocks, modules and circuits described in connection with the present disclosure. The processing device may also be a combination that realizes computing functions, for example, a combination of one or more microprocessors, a combination of DSP and a microprocessor, and the like.

The steps of the methods or algorithms described in conjunction with the embodiments of the present application may be implemented in hardware, or may be implemented in a manner in which a processor executes software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory (random access memory, RAM), flash memory, read-only memory (read-only memory, ROM) memory, erasable programmable read-only Memory (erasable programmable read-only memory, EPROM), electrically erasable programmable read-only memory (electrically erasable programmable read-only memory, EEPROM), registers, hard disk, mobile hard disk, compact disc read-only memory , CD-ROM) or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. Of course, the storage medium may also be a component of the processor. The processor and storage medium can be located in the ASIC. Additionally, the ASIC may be located in the first device. Of course, the processor and the storage medium may also exist in the first detecting device as discrete components.

It can be understood that Fig. 13 to Fig. 17 only show the simplified design of the signal transmitting device/signal processing device. In practical applications, the signal transmitting device/signal processing device may include any number of transmitters, receivers, processors, controllers, memories and other possible components.

Through the description of the above embodiments, those skilled in the art can clearly understand that for the convenience and brevity of the description, only the division of the above-mentioned functional modules is used as an example for illustration. In practical applications, the above-mentioned functions can be allocated according to needs It is completed by different functional modules, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

In the several embodiments provided in this application, it should be understood that the disclosed devices and methods may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be Incorporation or may be integrated into another device, or some features may be omitted, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The unit described as a separate component may or may not be physically separated, and the component displayed as a unit may be one physical unit or multiple physical units, that is, it may be located in one place, or may be distributed to multiple different places . Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the software product is stored in a storage medium Among them, several instructions are included to make a device (which may be a single-chip microcomputer, a chip, etc.) or a processor (processor) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: various media capable of storing program codes such as U disk, mobile hard disk, ROM, RAM, magnetic disk or optical disk.

The above is only the specific implementation of the embodiment of the application, but the scope of protection of the embodiment of the application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the application shall be covered in the implementation of the application. within the scope of protection of the example. Therefore, the protection scope of the embodiments of the present application should be based on the protection scope of the claims.

Claims

A signal transmission method, characterized in that the method comprises:

Determine N pulse sequences according to the encoding matrix; the encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) is less than the first preset Value; each pulse sequence corresponds to each row of the encoding matrix; the N is an integer greater than or equal to 2;

The N pulse sequences are transmitted.
The method according to claim 1, wherein, before determining the N pulse sequences according to the encoding matrix, further comprising:

Deleting the first row and first column of the first matrix to obtain a second matrix; any two rows of the first matrix are mutually orthogonal, and the relationship between the first matrix and the transpose of the first matrix The product of is an identity matrix; the first matrix is an N+1 order Hadamard matrix;

The element 1 in the second matrix is replaced by 0, and the element -1 in the second matrix is replaced by 1 to obtain an encoding matrix.
The method according to claim 1 or 2, characterized in that,

The absolute value of each element in a row of the encoding matrix is the amplitude value of each pulse signal in the corresponding pulse sequence, and one element corresponds to a time window, and the time window is used to send the pulse signal corresponding to the element.
The method according to any one of claims 1 to 3, characterized in that,

The time interval between the end time of the time window corresponding to the last pulse signal in the first pulse sequence and the start time of the time window corresponding to the first pulse signal in the second pulse sequence is equal to or greater than the maximum round-trip time;

The first pulse sequence and the second pulse sequence are pulse sequences corresponding to two adjacent rows in the encoding matrix, respectively, and the maximum round-trip time is the maximum round-trip time between a pulse signal and the measured object.
A signal processing method, characterized in that the method comprises:

receiving echo signals of N pulse sequences;

Decoding the echo signals of the N pulse sequences according to the inverse matrix of the coding matrix to obtain the echo signal of the single pulse signal;

The single pulse signal is a pulse signal in the N pulse sequences; the encoding matrix is an N-order reversible matrix, and the absolute value of each element in the inverse matrix of the encoding matrix is equal to 2/(N+1 ) is less than the first preset value; the N is an integer greater than or equal to 2.
The method according to claim 5, characterized in that, according to the inverse matrix of the coding matrix, the echo signals of the N pulse sequences are decoded to obtain the echo signals of a single pulse signal, including:

Determine the echo signals of N single pulse signals according to the inverse matrix of the encoding matrix and the echo signals of the N pulse sequences;

Time delay correction is performed on the echo signals of the N single pulse signals, and an average value of the N time delay corrected echo signals is determined.
A signal transmission method, characterized in that the method comprises:

determining a pulse sequence based on the first sequence;

transmitting said pulse sequence one or more times;

The first sequence is determined according to a recursive formula, and the recursive formula is

The n=1,...,(N+1)/2; the N is a prime number.
The method according to claim 7, wherein the method further comprises:

Determine (N+1)/2 values {u n } according to the recursive formula;

Set the {u n }th value in the all-zero sequence of length N to 1 to obtain the first sequence of length N.
The method according to claim 7 or 8, characterized in that,

The absolute value of each element in the first sequence is the amplitude value of each pulse signal in the pulse sequence;

Each element corresponds to a time window, and the time window is used to send the pulse signal corresponding to the element.
The method according to any one of claims 7 to 9, characterized in that,

When the pulse sequence corresponding to the first sequence is transmitted multiple times, the end time of the time window corresponding to the last pulse signal in the first pulse sequence is the same as the time window corresponding to the first pulse signal in the second pulse sequence The time interval between start times, equal to or greater than the maximum round trip time;

The first pulse sequence and the second pulse sequence are pulse sequences transmitted twice adjacently; the maximum round-trip time is the maximum value of the round-trip time between a pulse signal and the measured object.
A signal processing method, characterized in that the method comprises:

receiving echo signals of one or more pulse trains;

Decoding the echo signals of the one or more pulse sequences according to the inverse matrix of the encoding matrix to obtain the echo signal of the single pulse signal;

The single pulse signal is a pulse signal in the one or more pulse sequences; the encoding matrix is an N-order reversible matrix, and the absolute value of each element in the inverse matrix of the encoding matrix is equal to 2/(N +1) The difference is smaller than the first preset value;

The N is an integer greater than or equal to 2.
The method according to claim 11, characterized in that the method further comprises:

Circularly shifting the first sequence to the right by 1 to (N-1) times to obtain (N-1) second sequences;

combining the first sequence and the (N-1) second sequences to obtain the encoding matrix of order N;

The first sequence is obtained according to a recursive formula, and the recursive formula is

The n=1,..., (N+1)/2, and the N is a prime number.
The method according to claim 11 or 12, wherein, according to the inverse matrix of the encoding matrix, decoding the echo signal of the one pulse sequence to obtain the echo signal of the single pulse signal comprises:

Dividing the echo signal of the one pulse sequence into N equally divided echo signals;

According to the N equally divided echo signals and the inverse matrix of the coding matrix, echo signals of N single pulse signals are determined.
The method according to claim 11 or 12, wherein, according to the inverse matrix of the encoding matrix, decoding the echo signals of the plurality of pulse sequences to obtain the echo signal of a single pulse signal comprises:

determining an average value of a plurality of echo signals according to the echo signals of the plurality of pulse sequences;

dividing the mean value of the plurality of echo signals into N equally divided echo signals;

The echo signals of N single pulse signals are determined according to the N equally divided echo signals and the inverse matrix of the coding matrix.
A signal transmitting device, characterized in that the device comprises:

The processing unit is used to determine N pulse sequences according to the encoding matrix; the encoding matrix is an N-order reversible matrix, and the difference between the absolute value of each element in the inverse matrix of the encoding matrix and 2/(N+1) less than the first preset value; each pulse sequence corresponds to each row of the encoding matrix; the N is an integer greater than or equal to 2;

A transmitting unit, configured to transmit the N pulse sequences.
The device according to claim 15, wherein before the processing unit determines the N pulse sequences according to the encoding matrix, it is further used for:

Deleting the first row and first column of the first matrix to obtain a second matrix; any two rows of the first matrix are mutually orthogonal, and the relationship between the first matrix and the transpose of the first matrix The product of is an identity matrix; the first matrix is an N+1 order Hadamard matrix;

The element 1 in the second matrix is replaced by 0, and the element -1 in the second matrix is replaced by 1 to obtain an encoding matrix.
The device according to claim 15 or 16, wherein the absolute value of each element in a row of the encoding matrix is the amplitude value of each pulse signal in the corresponding pulse sequence, and one element corresponds to a time window, This time window is used to send the pulse signal corresponding to this element.
Apparatus according to any one of claims 15 to 17, characterized in that

The time interval between the end time of the time window corresponding to the last pulse signal in the first pulse sequence and the start time of the time window corresponding to the first pulse signal in the second pulse sequence is equal to or greater than the maximum round-trip time;

The first pulse sequence and the second pulse sequence are pulse sequences corresponding to two adjacent rows in the encoding matrix, respectively, and the maximum round-trip time is the maximum round-trip time between a pulse signal and the measured object.
A signal processing device, characterized in that the device comprises:

a receiving unit, configured to receive echo signals of N pulse sequences;

A processing unit, configured to decode and process the echo signals of the N pulse sequences according to the inverse matrix of the coding matrix, to obtain the echo signal of a single pulse signal;

The single pulse signal is a pulse signal in the N pulse sequences; the encoding matrix is an N-order reversible matrix, and the absolute value of each element in the inverse matrix of the encoding matrix is equal to 2/(N+1 ) is less than the first preset value; the N is an integer greater than or equal to 2.
The device according to claim 19, wherein the processing unit decodes the echo signals of the N pulse sequences according to the inverse matrix of the coding matrix to obtain the echo signal of a single pulse signal, specifically using At:

Determine the echo signals of N single pulse signals according to the inverse matrix of the encoding matrix and the echo signals of the N pulse sequences;

Time delay correction is performed on the echo signals of the N single pulse signals, and an average value of the N time delay corrected echo signals is determined.
A signal transmitting device, characterized in that the device comprises:

a processing unit, configured to determine a pulse sequence according to the first sequence;

a transmitting unit, configured to transmit the pulse sequence one or more times;

The first sequence is determined according to a recursive formula, and the recursive formula is

The n=1,...,(N+1)/2; the N is a prime number.
The device according to claim 21, characterized in that,

The processing unit is further configured to determine (N+1)/2 values {u n } according to the recursive formula;

The processing unit is further configured to set the {u n }th value in the all-zero sequence of length N to 1, so as to obtain the first sequence of length N.
Apparatus according to claim 21 or 22, characterized in that

The absolute value of each element in the first sequence is the amplitude value of each pulse signal in the pulse sequence;

Each element corresponds to a time window, and the time window is used to send the pulse signal corresponding to the element.
Apparatus according to any one of claims 21 to 23, characterized in that

When the transmitting unit transmits multiple pulse sequences corresponding to the first sequence, the end time of the time window corresponding to the last pulse signal in the first pulse sequence corresponds to the first pulse signal in the second pulse sequence The time interval between the start times of the time window is equal to or greater than the maximum round-trip time;

The first pulse sequence and the second pulse sequence are pulse sequences transmitted twice adjacently; the maximum round-trip time is the maximum value of the round-trip time between a pulse signal and the measured object.
A signal processing device, characterized in that the device comprises:

a receiving unit, configured to receive echo signals of one or more pulse sequences;

A processing unit, configured to decode and process the echo signals of the one or more pulse sequences according to the inverse matrix of the coding matrix, to obtain the echo signal of the single pulse signal;

The single pulse signal is a pulse signal in the one or more pulse sequences; the encoding matrix is an N-order reversible matrix, and the absolute value of each element in the inverse matrix of the encoding matrix is equal to 2/(N +1) The difference is smaller than the first preset value;

The N is an integer greater than or equal to 2.
The device according to claim 25, characterized in that,

The processing unit is further configured to sequentially cyclically shift the first sequence to the right by 1 to (N-1) times to obtain (N-1) second sequences;

The processing unit is further configured to combine the first sequence and the (N-1) second sequences to obtain the encoding matrix of order N;

The first sequence is obtained according to a recursive formula, and the recursive formula is

The n=1,..., (N+1)/2, and the N is a prime number.
The device according to claim 25 or 26, wherein the processing unit decodes the echo signal of the one pulse sequence according to the inverse matrix of the encoding matrix to obtain the echo signal of a single pulse signal, specifically Used for:

Dividing the echo signal of the one pulse sequence into N equally divided echo signals;

According to the N equally divided echo signals and the inverse matrix of the coding matrix, echo signals of N single pulse signals are determined.
The device according to claim 25 or 26, wherein the processing unit decodes the echo signal of the one pulse sequence according to the inverse matrix of the encoding matrix to obtain the echo signal of a single pulse signal, specifically Used for:

determining an average value of a plurality of echo signals according to the echo signals of the plurality of pulse sequences;

dividing the mean value of the plurality of echo signals into N equally divided echo signals;

The echo signals of N single pulse signals are determined according to the N equally divided echo signals and the inverse matrix of the coding matrix.
A signal transmitting device, characterized in that the device includes: a processor and a transmitter; the processor is used to perform the corresponding function in the method according to any one of claims 1 to 4, or to perform the following The corresponding function in the method described in any one of claims 7 to 10; the transmitter is used to perform the corresponding function in the method described in claim 1, or is used to perform the corresponding function in the method described in claim 7 .
A signal processing device, characterized in that the device comprises: a processor and a receiver; the processor is used to perform the corresponding functions in the method according to claim 5 or 6, or to perform the corresponding functions in the method according to claim 11 The corresponding function in the method described in any one of claim 14; the receiver is used to perform the corresponding function of the method described in claim 5, or used to perform the corresponding function of the method described in claim 11.
A computer-readable storage medium, the computer-readable storage medium stores instructions, and when it is run on a computer, the method according to any one of claims 1 to 4 is executed, or the method according to claim 5 or 6 is executed. The method is performed, or causes the method described in any one of claims 7 to 10 to be performed, or causes the method described in any one of claims 11 to 14 to be performed.
A chip, characterized in that the chip includes: a processor and an interface, the processor is used to call and run instructions from the interface, when the processor executes the instructions, the implementation of claims 1 to 4 The method described in any one of the claims, or realize the method described in claim 5 or 6, or realize the method described in any one of claims 7 to 10, or realize the method described in any one of claims 11 to 14 described method.
A laser radar, characterized in that the laser radar comprises the device according to any one of claims 15 to 18, or comprises the device according to claim 19 or 20, or comprises the device according to claim 21 The device according to any one of claims 24 to 24, or comprising the device according to any one of claims 25 to 28.
A terminal device, characterized in that it includes the device according to any one of claims 15 to 18, or includes the device according to claim 19 or 20, or includes the device according to any one of claims 21 to 24 The device described in item, or, comprise the device described in any one of claims 25 to 28, or, comprise the device described in claim 29, or, comprise the device described in claim 30, or, comprise The computer-readable storage medium as claimed in claim 31, or comprising the chip as claimed in claim 32, or comprising the laser radar as claimed in claim 33.