WO2020223921A1 - Signal processing method, related device, and lora antenna system - Google Patents

Abstract

Disclosed are a signal processing method, a related device, and a LoRa antenna system. For a transmitting device, a bitstream is spread on the basis of a preset spreading factor to produce an initial spreading signal; the initial spreading signal is scrambled on the basis of a preset scrambling code sequence, where the group number of a scrambling code group in which the preset scrambling code sequence is found is characterized as group information of a terminal; preamble information is generated on the basis of the group information, and the preamble information and scrambled data information are packaged as data frames to be transmitted. The present invention implements the goal of reducing interference between uplink data frames of nodes employing a same spreading factor and increasing the capacity of the LoRa system.

Description

A signal processing method, related equipment and LoRa wireless system Technical field

The present invention relates to the field of wireless communication technology, in particular to a signal processing method, related equipment and a LoRa wireless system.

Background technique

With the rapid growth of the Internet of Things market, new communication scenarios have put forward new requirements for low power consumption and wide coverage for wireless transmission technology. In order to meet the requirements of wireless transmission technology, a long-distance LoRa wireless transmission scheme based on Chirp spread spectrum technology is usually used.

In order to ensure the transmission quality of wireless signals, the existing solutions are usually implemented by reducing the mutual interference between nodes, that is, the nodes in the network are divided into areas according to the distance from the gateway, and different nodes are allocated to different areas. Spreading factor. Although the interference between partitions is controlled to a certain extent in the existing technical solutions, there are still a large number of nodes using the same SF (Spreading Factor) through the ALOHA method in the high-density and massive device access scenario of the Internet of Things Contend for the wireless channel, so the problem of mutual interference between uplink signals of the same SF is not really solved. In the LoRa system, the uplink interference between nodes using the same SF will cause the average PER (Packet Error Rate) of the system to increase, which severely limits the system capacity of LoRa and makes the system capacity quickly reach saturation.

Summary of the invention

In view of the above-mentioned problems, the present invention provides a signal processing method, related equipment and a LoRa wireless system to reduce the interference between uplink data frames of nodes using the same spreading factor and improve the capacity of the LoRa system.

In order to achieve the above objective, the present invention provides the following technical solutions:

A signal processing method applied to a sending device, the method including:

Perform spread spectrum processing on the bit stream according to the preset spreading factor to obtain the initial spread spectrum signal;

Performing scrambling processing on the initial spread spectrum signal based on a preset scrambling code sequence to obtain a scrambled data signal;

The preamble signal and the scrambled data signal are encapsulated into a data frame to be transmitted for transmission by the transmitting device.

Optionally, it also includes:

The group number of the scrambling code group in which the preset scrambling code sequence is located is characterized as the group information of the sending device, and the group information is added to the preamble signal.

Optionally, the preamble signal includes several original Chirp signals and Chrip signals modulated by the group of information, and the original Chirp signals represent chirp signals.

Optionally, the performing spreading processing on the bit stream according to a preset spreading factor to obtain an initial spreading signal includes:

Intercept the bit stream according to the preset spreading factor;

The decimal number corresponding to the bit segment obtained by the interception is used as an offset, and the original Chirp signal is spread spectrum modulated according to the offset to obtain an initial spread spectrum signal.

Optionally, the performing scrambling processing on the initial spread spectrum signal based on a preset scrambling code sequence to obtain a scrambled data signal includes:

The initial spread spectrum signal is multiplied by the preset scrambling code sequence through a multiplier to realize the scrambling processing of the initial spread spectrum signal, and the scrambled data information is obtained.

A signal processing method applied to a receiving device, the method including:

Receive the target signal sent by the sending device;

Extracting a preamble signal in the target signal, and estimating a time offset according to the preamble signal, where the time offset is a time offset between the sending device and the receiving device out of synchronization;

Synchronize with the sending device according to the time offset;

Query in the preset descrambling sequence list to obtain the descrambling sequence corresponding to the target signal;

Descrambling the target signal according to the descrambling sequence to obtain an initial spread spectrum signal;

Despreading the initial spread spectrum signal to obtain a bit stream.

Optionally, the method further includes:

Extracting group information in the preamble signal, where the group information is the group number of the scrambling code group where the scrambling code sequence added by the sending device to the target signal is located; and

Based on the group information, query in a preset group information association table to obtain the descrambling sequence corresponding to the target signal.

A sending device, including:

The spread spectrum module is used to perform spread spectrum processing on the bit stream according to a preset spread spectrum factor to obtain an initial spread spectrum signal;

The scrambling module is configured to perform scrambling processing on the initial spread spectrum signal based on a preset scrambling code sequence to obtain a scrambled data signal;

The preamble adding module is used to encapsulate the preamble signal and the scrambled data signal into a data frame to be transmitted for transmission by the sending device.

Optionally, the group number of the scrambling code group where the preset scrambling code sequence in the scrambling module is located is characterized as the group information of the sending device, and the group information is added to the preamble signal.

Optionally, the preamble signal in the preamble adding module includes several original Chirp signals and Chrip signals modulated by the set of signals, and the original Chirp signals represent chirp signals.

Optionally, the spread spectrum module includes:

The interception unit is used to intercept the bit stream according to the preset spreading factor;

The spreading unit is configured to use the decimal number corresponding to the bit segment obtained by truncation as an offset, and perform spread spectrum modulation on the original Chirp signal according to the offset to obtain an initial spreading symbol.

Optionally, the scrambling module is specifically configured to:

The initial spread spectrum signal is multiplied by the preset scrambling code sequence through a multiplier to realize the scrambling processing of the initial spread spectrum signal, and the scrambled data information is obtained.

A receiving device, including:

The receiving module is used to receive the target signal sent by the sending device;

The estimation module is used to extract the preamble signal in the target signal and estimate the time offset according to the preamble signal, where the time offset is the time when the sending device and the receiving device are out of sync Offset;

A synchronization module, configured to synchronize with the sending device according to the time offset;

The query module is configured to query the preset descrambling sequence list to obtain the descrambling sequence corresponding to the target signal;

The descrambling module is configured to descramble the target signal according to the descrambling sequence to obtain an initial spread spectrum signal;

The despreading module is used for despreading the initial spread spectrum signal to obtain a bit stream.

Optionally, the receiving device further includes:

The extraction module is used to extract group information in the preamble signal, where the group information is the group number of the scrambling code group where the scrambling code sequence added by the sending device to the target signal is located; and based on the group information The descrambling sequence corresponding to the target signal is obtained by querying the preset group information association table.

A LoRa wireless system, including:

The sending device described above and the receiving device described above.

A communication device having a memory and a processor coupled with the memory, the memory storing one or more programs, and when the one or more programs are executed on the processor, any one of the above is implemented The signal processing method.

A computer-readable storage medium in which one or more programs are stored, and when the one or more programs are executed on a processor, the signal processing method described in any one of the above is implemented.

Compared with the prior art, the present invention provides a signal processing method, related equipment, and a LoRa wireless system. The transmission device performs spreading, scrambling and preamble processing on the bit stream, and adding a scrambling code sequence to the data. The scrambling realizes the protection of the data part, and the orthogonality of the scrambling code can effectively solve the problem of mutual interference of uplink data frames between nodes using the same spreading factor. In this scheme, the total scrambling code sequence is grouped, so When the receiving device performs descrambling, it can search for the corresponding descrambling sequence through the preamble information, so that the descrambling delay is maintained within the allowable range of the wireless system, thereby reducing the interference between the uplink data frames of the nodes using the same spreading factor. Improved the capacity of the LoRa wireless system.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without creative work.

FIG. 1 is a schematic flowchart of a signal processing method according to an embodiment of the present invention;

2 is a schematic flowchart of another signal processing method provided by an embodiment of the present invention;

3 is a schematic diagram of a signal processing flow of a LoRa wireless system provided by an embodiment of the present invention;

4 is a schematic diagram of a time length change of a collision zone according to an embodiment of the present invention;

Figure 5a is a schematic diagram of the detection result of the LoRa system in the prior art provided by the present invention;

FIG. 5b is a schematic diagram of a detection result of a LoRa wireless system provided by an embodiment of the present invention;

FIG. 6 is a schematic diagram of preamble and data collision according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a preamble signal detection result provided by an embodiment of the present invention;

Fig. 8 is a schematic diagram of baseband simulation results provided by the present invention;

9 is a schematic diagram of a simplified synchronous circuit design provided by an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a sending device according to an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of a receiving device according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

The terms "first" and "second" in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific sequence. In addition, the terms "including" and "having" and any variations of them are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not set in the listed steps or units, but may include unlisted steps or units.

The embodiment of the present invention provides a signal processing method, which is applied to a sending device. Referring to FIG. 1, the method may include the following steps:

S11. Perform spreading processing on the bit stream according to a preset spreading factor to obtain an initial spreading signal;

S12: Perform scrambling processing on the initial spread spectrum signal based on a preset scrambling code sequence to obtain a scrambled data signal;

S13. Encapsulate the preamble signal and the scrambled data signal into a data frame to be transmitted for transmission by the transmitting device.

It should be noted that the LoRa wireless system provided in the embodiment of the present invention is implemented based on code division multiple access technology. Code Division Multiple Access (CDMA) is based on spread spectrum technology. The information data that needs to be transmitted with a certain signal bandwidth is multiplied by a high-speed pseudo-random code with a bandwidth much larger than the signal bandwidth to make the original data signal The bandwidth is expanded and then sent out after carrier modulation. Chirp spread spectrum technology is used in the embodiment of the present invention. The group number of the scrambling code group where the preset scrambling code sequence is located represents the group information of the sending device, and the group information is added to the preamble signal.

The preamble signal (hereinafter referred to as preamble for short) in the embodiment of the present invention includes several original Chrip signals and Chirp signals modulated by the group information. Among them, the original Chrip signal represents a linear frequency modulation signal in the usual sense, and the original Chrip signal refers to a signal generated by modulation of a bit stream, such as a signal generated after a bit stream is modulated by BPSK.

Step S11 may include the following steps:

Intercept the bit stream according to the preset spreading factor;

The decimal number corresponding to the bit segment obtained by the truncation is used as the offset, and the Chirp signal is spread spectrum modulated according to the offset to obtain the initial spread spectrum symbol.

Step S12 may specifically be:

The spread spectrum signal is multiplied by the preset scrambling code sequence through a multiplier to realize the scrambling process of the initial spread spectrum signal to obtain scrambled data information.

First, the binary bit stream is intercepted in segments according to the spreading factor (SF) used by the sending device (where the sending device can be understood as a terminal device). In the embodiment of the present invention, each SF bit intercepted is used to modulate a Chirp symbol. The decimal number corresponding to the intercepted SF bits is used as the offset of the Chirp symbol cyclic shift, and the data bit stream realizes Chirp spread spectrum modulation in the above-mentioned manner. After the spread spectrum signal is multiplied by the scrambling code by the multiplier, the leading signal is added at the front end. The preamble signal is composed of several original Chirp signals and signals modulated by group information, and the group number of the scrambling code group where the preset scrambling code is located represents the group information of the terminal. Chirp in the embodiment of the present invention is a chirp signal in the usual sense.

The embodiment of the present invention also provides a signal processing method, which is applied to a receiving device. Referring to FIG. 2, the method may include the following steps:

S21. Receive the target signal sent by the sending device;

S22. Extract a preamble signal in the target signal, and estimate a time offset according to the preamble signal, where the time offset is the time offset between the sending device and the receiving device out of synchronization ；

S23. Synchronize with the sending device according to the time offset;

S24: Query in a preset descrambling sequence list to obtain a descrambling sequence corresponding to the target signal;

S25. Descramble the target signal according to the descrambling sequence to obtain an initial spread spectrum signal;

S26. Perform despreading processing on the initial spread spectrum signal to obtain a bit stream.

In the receiving device (which can be understood as a base station device), first extract the preamble signal of the received target signal, multiply it with the original Chirp complex conjugate signal, and perform FFT (Fast Fourier Transformation, fast discrete Fourier Transformation) processing and estimation The time offset of the out-of-synchronization between the receiving device and the sending device is obtained, and the accurate synchronization of the sending device and the receiving device can be realized by using the time offset. For example, SF=7, a Chirp symbol corresponds to 7 bits and 128 chips (2 ⁷ ). The receiving side of the gateway does not necessarily start to receive the signal at the beginning of the Chirp symbol. For example, it may be in the middle of a Chirp symbol (the 50th code). After receiving the signal, the gateway side estimates the offset (50) after digital signal processing, that is, knowing that it is received from the 50th chip, it can accurately find the beginning of a Chirp symbol. The start position and subsequent symbols are all aligned accordingly, thus achieving symbol synchronization.

After synchronization, the group information carried in the preamble is extracted, and the scrambling code set of the corresponding group is queried in the group information association table stored in the group information of the sending device, and only the correct descrambling sequence is searched in the scrambling code set , It greatly reduces the calculation amount and processing delay of searching scrambling code sequence when the receiver descrambles. After the signal is descrambled, the Chirp despreading process is performed to finally recover the information bit stream.

Through the signal processing method provided by the embodiment of the present invention, the bit stream is spread, scrambled, and preamble added is performed on the transmitting device, and the data part is protected by introducing the scrambling code sequence to the data. Orthogonality can effectively solve the problem of mutual interference of uplink data frames between nodes using the same spreading factor. And in this solution, the total scrambling code sequence is grouped so that when the receiving device performs descrambling, the corresponding descrambling sequence can be obtained through the preamble search, so that the descrambling delay is maintained within the allowable range of the wireless system, thereby reducing the use of The interference between uplink data frames of nodes with the same spreading factor increases the capacity of the LoRa wireless system.

In the embodiment of the present invention, a LoRa wireless system is also provided. See FIG. 3, which includes a sending device and a receiving device. The corresponding sending device can be understood as a node device, and the receiving device can be understood as a gateway and related devices. The LoRa wireless system will now be described according to an embodiment of the present invention.

Assuming that the SF of the sending device is set to 7, the group information is 2, and the scrambling sequence adopts an extended 7-order m-sequence with a length of 128 (the first bit of the 7-order m-sequence with a length of 127 is padded to the end and extended to 128) .

At the terminal, the binary bit stream is first segmented according to a group of 7 bits. It is assumed that a segment of the bit is grouped as [0 0 1 0 0 0 0], which means 16 in decimal, and the duration is 128 chip times The Chirp symbol is cyclically shifted by 16 chip periods, and the spread signal (the signal sampling rate is taken as a sample point for each chip) is multiplied by the extended 7-order m sequence through the multiplier, and the product signal is added in front of The preamble consisting of 7 original Chirp symbols and 1 Chirp symbol modulated by group information (the symbol carrying group information cannot be the first or last symbol) is used for synchronization offset detection and descrambling processing of the receiving device.

In the receiving device, first extract the preamble of the received signal, multiply it with the complex conjugate signal of the original Chirp, and then perform 128-point FFT processing. The time offset corresponding to the maximum spectral amplitude is the estimated out-of-synchronization time offset The amount of movement is compensated to achieve precise synchronization. After synchronization is achieved, the Chirp symbol carrying the group information is multiplied by the original Chirp's complex conjugate signal, and the group information is obtained after 128-point FFT processing. The gateway determines the scrambling code sequence search space according to the scrambling code set corresponding to the second group in the group information association table. In the second group of scrambling code sets, the correct scrambling code sequence is searched for in a traversal manner to descramble the data. After the data is descrambled, the despreading operation is completed according to the standard LoRa processing flow, and the information bit stream is finally restored.

Referring to FIG. 4, assuming that the duration of the standard LoRa data frame in the prior art is T, the data frame is composed of two parts: a preamble and a data. The scrambling of the data by the scrambling code realizes the protection of the data part, that is, the duration of the collision zone can be reduced from the entire data frame duration T to the preamble duration T1. According to the value of each parameter of the data frame given by the LoRaWAN protocol, T1<<T can be obtained. Therefore, the probability of collision of the uplink data frame of the code division multiple access LoRa system is greatly reduced. The orthogonality of the scrambling code can effectively solve the problem. The problem of mutual interference of uplink data frames between SF nodes.

If the signal 1 and signal 2 with the same signal-to-noise ratio in the standard LoRa system overlap in the time domain during transmission, the information offset of Chirp spread spectrum modulation is 11 and 13, respectively. The two signals interfere with each other. After the machine signal is processed, aliasing occurs in the frequency domain and cannot be distinguished, as shown in Figure 5a. The code division multiple access LoRa system assigns different scrambling code sequences to the two nodes. Even if the two signals collide during transmission, the receiver can still distinguish between the two signals and complete the detection after descrambling. , As shown in Figure 5b.

The scene where the leader collides with the data is shown in Figure 6. At this time, it is verified by simulation: under the existing LoRa system, the lower limit SIR of the preamble signal is 6dB, as shown in part a in Figure 7, and the lower limit SIR of the code division multiple access LoRa system is -8dB, as This is shown in part b in Figure 7. By introducing code division technology through scrambling, the system obtains a gain of 14dB. For the LoRa system, synchronization through the preamble is a necessary prerequisite for the data payload to be successfully detected. Therefore, the correct detection probability of the code division multiple access LoRa system will greatly increase.

According to the foregoing analysis, the code division multiple access technology can effectively reduce the mutual interference between nodes using the same SF in the system. The performance improvement in the system due to the reduction of the interference level is mainly reflected in the increase in the capacity of the single gateway system. In the OPNET simulation environment, a system simulation was performed for a high-density scenario with a single gateway and evenly distributed nodes. The simulation parameters are shown in Table 1. As shown in Table 2, the simulation results show that: Compared with the standard LoRa system, the single-gateway system capacity of the code division multiple access LoRa wireless system has increased by 114%.

Table 1

Simulation parameters	Parameter value
Number of gateways	1 piece
Coverage	1km 2
Node topology	Evenly distributed
Transmit power	17dBm
Node uses SF	7

System target packet error rate

10%

Table 2

The single-site coverage of the system is one of the important indicators to measure system performance. The link budget is a commonly used evaluation method for evaluating communication systems. The following uses the link budget to analyze whether the introduction of code division multiple access has an impact on the coverage of the LoRa system. The calculation expression of the maximum allowable path loss PL is:

PL=I-PRX+R+S+U-V-W-X+Y-Z

Among them, I is equivalent transmit power, PRX is receiver sensitivity, R is receiving antenna gain, S is receiving antenna shaping gain, U is receiving antenna diversity gain, V is receiving feeder loss, W is fast fading margin, X Is the shadow fading margin, Y is the switching gain, and Z is the wall penetration loss. After analysis, among the variables at the right end of the equation, the only variable affected by CDMA is and only the receiver sensitivity PRX. Therefore, whether the system coverage distance changes is equivalent to whether the receiver sensitivity PRX changes. The receiver sensitivity is analyzed below, the calculation expression of receiver sensitivity PRX is:

PRX=RNF-SNR=N ₀ +NF-SNR=10lg(KTB)+NF-SNR

Among them, RNF is the receiver noise floor, SNR is the signal-to-noise ratio required to achieve the target bit error rate, N ₀ is the thermal noise level, NF is the system noise figure, K is the Boltzmann constant, T is the absolute temperature, and B Is the system bandwidth. It can be seen from the above formula that among all the variables that affect the PRX sensitivity of the receivers of the two systems, only the SNR required to achieve the target bit error rate is different. The change of the system coverage distance is ultimately attributed to whether the SNR required to achieve the target bit error rate changes. The simulation software of MATLAB was used to simulate the baseband of the system under AWGN channel and Rayleigh channel. As can be seen in part a in Figure 8: in the AWGN channel, the standard LoRa and code division multiple access LoRa systems require the same SNR under the same BER conditions; under the Rayleigh multipath channel in the typical urban area in part b in Figure 8, compared to the standard LoRa system , The code division multiple access LoRa system has 0.5dB gain (can be regarded as approximately the same). Therefore, the following conclusions can be drawn: the introduction of code division multiple access will not adversely affect the sensitivity of the receiver, that is, while the code division multiple access LoRa system increases system capacity, the coverage of a single gateway remains unchanged.

The code division multiple access LoRa wireless system assigns a scrambling code to each node. In the face of the massive connection of the Internet of Things, the total amount of scrambling code sequences in the total scrambling code set will be very large. If you use the global traversal method to descramble the signal , Increase the number of calculations and delay on the gateway side. When multiple lines of data are concurrently concurrent, the calculation processing delay caused by the global traversal will be intolerable to the system. The innovative solution is to group the total scrambling code set, and the group number of the scrambling code used by each node is the group information of the node; the group information is modulated into a Chirp symbol in the preamble, and the remaining Chirp Symbols are still used synchronously. The receiver obtains the group information after synchronization, and according to the group information and the stored group information association table, it only searches for the correct scrambling code sequence in the group by traversal to realize the descrambling operation. The foregoing solution greatly reduces the computational complexity in the process of de-scrambling, while maintaining the de-scrambling delay within the tolerable range of the system.

For a direct sequence spread spectrum system, to achieve despreading/descrambling, the phase of the receiver's local reference spreading code/scrambling code sequence must be exactly the same as the phase of the received spreading code/scrambling code sequence, which leads to a direct spread system The synchronization circuit is very complicated. The code division multiple access LoRa system follows the synchronization mechanism of the standard LoRa system. The precise synchronization of the signal can be achieved through the Chirp preamble signal, eliminating the need for the capture circuit and tracking circuit of the direct spread system (the part in the bold dashed box in Figure 9) , While reducing the cost, it also ensures that the signal processing delay is within the allowable range. The schematic diagram of the simplified synchronization circuit design is shown in Figure 9.

The embodiments of the present invention are suitable for application scenarios of low power consumption, wide coverage, high density, and massive node device access in the field of Internet of Things, including but not limited to smart meter reading (water meter, electric meter, gas meter, etc.), smart municipal, smart Transportation, precision agriculture, smart buildings, smart cities, smart homes, etc. In addition, this innovation is also applicable to any long-distance communication scenarios with low power consumption, wide coverage, high density, and massive node device access that LoRa is suitable for use.

The embodiment of the present invention also provides a sending device 10, referring to FIG. 10, including:

The spreading module 101 is configured to perform spreading processing on the bit stream according to a preset spreading factor to obtain an initial spreading signal;

The scrambling module 102 is configured to perform scrambling processing on the initial spread spectrum signal based on a preset scrambling code sequence to obtain a scrambled data signal;

The preamble adding module 103 is configured to encapsulate the preamble signal and the scrambled data signal into a data frame to be transmitted for transmission by the sending device.

On the basis of the foregoing embodiment, the group number of the scrambling code group where the preset scrambling code sequence in the scrambling module is located is characterized as the group information of the sending device, and the group information is added to the preamble signal.

The preamble signal in the preamble adding module includes several original Chirp signals and Chrip signals modulated by the group of signals, and the original Chirp signals represent the chirp signal.

On the basis of the foregoing embodiment, the spread spectrum module 101 includes:

The interception unit is used to intercept the bit stream according to the preset spreading factor;

The spreading unit is configured to use the decimal number corresponding to the bit segment obtained by truncation as an offset, and perform spread spectrum modulation on the original Chirp signal according to the offset to obtain an initial spreading symbol.

On the basis of the foregoing embodiment, the scrambling module 102 is specifically configured to:

The initial spread spectrum signal is multiplied by the preset scrambling code sequence through a multiplier to realize the scrambling processing of the initial spread spectrum signal, and the scrambled data information is obtained.

Correspondingly, an embodiment of the present invention also provides a base station 20, referring to FIG. 11, including:

The receiving module 201 is used to receive the target signal sent by the sending device;

The estimation module 202 is configured to extract a preamble signal in the target signal, and estimate a time offset according to the preamble signal, where the time offset is the result of the loss of synchronization between the sending device and the receiving device Time offset

The synchronization module 203 is configured to synchronize with the sending device according to the time offset;

The query module 204 is configured to query the preset descrambling sequence list to obtain the descrambling sequence corresponding to the target signal;

The descrambling module 205 is configured to descramble the target signal according to the descrambling sequence to obtain an initial spread spectrum signal;

The despreading module 206 is configured to perform despreading processing on the initial spread spectrum signal to obtain a bit stream.

On the basis of the foregoing embodiment, the receiving device 20 further includes:

The extraction module is used to extract group information in the preamble signal, where the group information is the group number of the scrambling code group where the scrambling code sequence added by the sending device to the target signal is located; and based on the group information The descrambling sequence corresponding to the target signal is obtained by querying the preset group information association table.

On the basis of the above-mentioned embodiment, another embodiment of the present invention also provides a LoRa system, which includes:

For the sending device and the receiving device described above, please refer to the foregoing embodiments, and details are not described here.

In the embodiment of the present invention, the transmitting device performs the processing of spreading, scrambling and adding the preamble to the bit stream, and the data part is protected by introducing the scrambling code to the data. The orthogonality of the scrambling code can be used to effectively solve the problem. The problem of mutual interference between uplink data frames between nodes with the same spreading factor, and the total scrambling code sequence is grouped in this scheme, so that when the receiving device performs descrambling, the corresponding descrambling sequence can be obtained through the preamble search , So that the descrambling delay is maintained within the allowable range of the wireless system, thereby reducing the interference between uplink data frames of nodes using the same spreading factor, and improving the capacity of the LoRa wireless system.

In the embodiment of the present invention, there is also provided a communication device, which has a memory and a processor coupled with the memory, the memory stores one or more programs, and when the one or more programs are in the processor When executed, the following methods are implemented:

A signal processing method applied to a sending device, the method including:

Perform spread spectrum processing on the bit stream according to the preset spreading factor to obtain the initial spread spectrum signal;

Performing scrambling processing on the initial spread spectrum signal based on a preset scrambling code sequence to obtain a scrambled data signal;

The preamble signal and the scrambled data signal are encapsulated into a data frame to be transmitted for transmission by the transmitting device.

Further, it also includes:

The group number of the scrambling code group in which the preset scrambling code sequence is located is characterized as the group information of the sending device, and the group information is added to the preamble signal.

Further, the preamble signal includes several original Chirp signals and Chrip signals modulated by the set of information, and the original Chirp signals represent chirp signals.

Further, the performing spreading processing on the bit stream according to the preset spreading factor to obtain the initial spreading signal includes:

Intercept the bit stream according to the preset spreading factor;

The decimal number corresponding to the bit segment obtained by the interception is used as an offset, and the original Chirp signal is spread spectrum modulated according to the offset to obtain an initial spread spectrum signal.

Further, the performing scrambling processing on the initial spread spectrum signal based on a preset scrambling code sequence to obtain a scrambled data signal includes:

The initial spread spectrum signal is multiplied by the preset scrambling code sequence through a multiplier to realize the scrambling processing of the initial spread spectrum signal, and the scrambled data information is obtained.

and / or

A signal processing method applied to a receiving device, the method including:

Receive the target signal sent by the sending device;

Extracting a preamble signal in the target signal, and estimating a time offset according to the preamble signal, where the time offset is a time offset between the sending device and the receiving device out of synchronization;

Synchronize with the sending device according to the time offset;

Query in the preset descrambling sequence list to obtain the descrambling sequence corresponding to the target signal;

Descrambling the target signal according to the descrambling sequence to obtain an initial spread spectrum signal;

Despreading the initial spread spectrum signal to obtain a bit stream.

Further, the method further includes:

Extracting group information in the preamble signal, where the group information is the group number of the scrambling code group where the scrambling code sequence added by the transmitting device to the target signal is located; and

Based on the group information, query in a preset group information association table to obtain the descrambling sequence corresponding to the target signal.

The embodiment of the present invention provides a storage medium readable by a computing device. When one or more programs are stored on the storage medium to be executed on a processor, the steps of any one of the foregoing signal processing methods are stored.

Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

This application is described with reference to flowcharts and/or block diagrams of methods, equipment (systems), and computer program products according to the embodiments of this application. It should be understood that each process and/or block in the flowchart and/or block diagram, and the combination of processes and/or blocks in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing equipment to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing equipment are generated It is a device that realizes the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing equipment to work in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction device. The device implements the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment. The instructions provide steps for implementing functions specified in a flow or multiple flows in the flowchart and/or a block or multiple blocks in the block diagram.

In a typical configuration, the computing device includes one or more processors (CPU), input/output interfaces, network interfaces, and memory.

The memory may include non-permanent memory in a computer readable medium, random access memory (RAM) and/or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.

Computer-readable media include permanent and non-permanent, removable and non-removable media, and information storage can be realized by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disc (DVD) or other optical storage, Magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media can be used to store information that can be accessed by computing devices. According to the definition in this article, computer-readable media does not include transitory media, such as modulated data signals and carrier waves.

It should also be noted that the terms "include", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, product or equipment including a series of elements not only includes those elements, but also includes Other elements that are not explicitly listed, or include elements inherent to this process, method, commodity, or equipment. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other identical elements in the process, method, commodity or equipment that includes the element.

Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, this application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

The above are only examples of the application, and are not used to limit the application. For those skilled in the art, this application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the scope of the claims of this application.

Claims (17)

1. A signal processing method, characterized in that it is applied to a sending device, and the method includes:

   Perform spread spectrum processing on the bit stream according to the preset spreading factor to obtain the initial spread spectrum signal;

   Performing scrambling processing on the initial spread spectrum signal based on a preset scrambling code sequence to obtain a scrambled data signal;

   The preamble signal and the scrambled data signal are encapsulated into a data frame to be transmitted for transmission by the transmitting device.
2. The method according to claim 1, further comprising:

   The group number of the scrambling code group in which the preset scrambling code sequence is located is characterized as the group information of the sending device, and the group information is added to the preamble signal.
3. The method according to claim 2, wherein the preamble signal comprises several original Chirp signals and Chrip signals modulated by the set of information, and the original Chirp signals represent chirp signals.
4. The method according to claim 3, wherein the performing spreading processing on the bit stream according to a preset spreading factor to obtain an initial spreading signal comprises:

   Intercept the bit stream according to the preset spreading factor;

   The decimal number corresponding to the bit segment obtained by the interception is used as an offset, and the original Chirp signal is spread spectrum modulated according to the offset to obtain an initial spread spectrum signal.
5. The method according to claim 1, wherein the performing scrambling processing on the initial spread spectrum signal based on a preset scrambling code sequence to obtain a scrambled data signal comprises:

   The initial spread spectrum signal is multiplied by the preset scrambling code sequence through a multiplier to realize the scrambling processing of the initial spread spectrum signal, and the scrambled data information is obtained.
6. A signal processing method, characterized in that it is applied to a receiving device, and the method includes:

   Receive the target signal sent by the sending device;

   Extracting a preamble signal in the target signal, and estimating a time offset according to the preamble signal, where the time offset is a time offset between the sending device and the receiving device out of synchronization;

   Synchronize with the sending device according to the time offset;

   Query in the preset descrambling sequence list to obtain the descrambling sequence corresponding to the target signal;

   Descrambling the target signal according to the descrambling sequence to obtain an initial spread spectrum signal;

   Despreading the initial spread spectrum signal to obtain a bit stream.
7. The method of claim 5, wherein the method further comprises:

   Extracting group information in the preamble signal, where the group information is the group number of the scrambling code group where the scrambling code sequence added by the transmitting device to the target signal is located; and

   Based on the group information, query in a preset group information association table to obtain the descrambling sequence corresponding to the target signal.
8. A sending device, characterized in that it comprises:

   The spread spectrum module is used to perform spread spectrum processing on the bit stream according to a preset spread spectrum factor to obtain an initial spread spectrum signal;

   The scrambling module is configured to perform scrambling processing on the initial spread spectrum signal based on a preset scrambling code sequence to obtain a scrambled data signal;

   The preamble adding module is used to encapsulate the preamble signal and the scrambled data signal into a data frame to be transmitted for transmission by the sending device.
9. The sending device according to claim 8, wherein the group number of the scrambling code group where the preset scrambling code sequence in the scrambling module is represented is the group information of the sending device, and is included in the preamble signal Add the group information.
10. 9. The transmitting device according to claim 9, wherein the preamble signal in the preamble adding module includes several original Chirp signals and Chrip signals modulated by the group of signals, and the original Chirp signals represent chirp signals.
11. The sending device according to claim 8, wherein the spreading module comprises:

    The interception unit is used to intercept the bit stream according to the preset spreading factor;

    The spreading unit is configured to use the decimal number corresponding to the bit segment obtained by the interception as an offset, and perform spread spectrum modulation on the Chirp signal according to the offset to obtain an initial spreading symbol.
12. The sending device according to claim 8, wherein the scrambling module is specifically configured to:

    The initial spread spectrum signal is multiplied by the preset scrambling code sequence through a multiplier to realize the scrambling processing of the initial spread spectrum signal, and the scrambled data information is obtained.
13. A receiving device, characterized by comprising:

    The receiving module is used to receive the target signal sent by the sending device;

    The estimation module is used to extract the preamble signal in the target signal and estimate the time offset according to the preamble signal, where the time offset is the time when the sending device and the receiving device are out of sync Offset;

    A synchronization module, configured to synchronize with the sending device according to the time offset;

    The query module is configured to query the preset descrambling sequence list to obtain the descrambling sequence corresponding to the target signal;

    The descrambling module is configured to descramble the target signal according to the descrambling sequence to obtain an initial spread spectrum signal;

    The despreading module is used for despreading the initial spread spectrum signal to obtain a bit stream.
14. The receiving device according to claim 13, wherein the receiving device further comprises:

    The extraction module is used to extract group information in the preamble signal, where the group information is the group number of the scrambling code group where the scrambling code sequence added by the sending device to the target signal is located; and based on the group information The descrambling sequence corresponding to the target signal is obtained by querying the preset group information association table.
15. A LoRa wireless system, characterized in that it comprises:

    The transmitting device according to claims 8-12 and the receiving device according to claims 13-14.
16. A communication device having a memory and a processor coupled with the memory, the memory storing one or more programs, and when the one or more programs are executed on the processor, claim 1- 7. The method described in any one of 7.
17. A computer-readable storage medium, in which one or more programs are stored, and when the one or more programs are executed on a processor, the method according to any one of claims 1-7 is realized.

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