A method of transmitting an ultra-wideband positioning signal that is tightly coupled with a narrowband communication signal

Abstract

The present application belongs to the field of positioning and navigation technology, and provides a kind of ultra-wideband positioning signal transmission method with narrowband communication signal tight coupling, including a kind of narrowband signal coupling ultra-wideband signal design method and a kind of communication information assisted positioning service process.Based on the narrowband assisted ultra-wideband signal designed and transmitted based on the method, the characteristic is that the ultra-wideband positioning signal is time-domain tightly coupled with the narrowband communication signal, and the narrowband communication signal can be used to realize the functions of wake-up, access control and other functions of ultra-wideband radio terminal, and can also transmit channel impulse response, navigation text and other information.Compared with the traditional ultra-wideband positioning system, more flexible terminal access mechanism can be realized, and the user capacity of the positioning base station is improved, which can be used on the ultra-wideband positioning base station and terminal with ranging and angle measurement capability.

Description

TECHNICAL FIELD

[0001] The application relates to a kind of ultra-wideband positioning signal transmission methods with narrowband communication signal tight coupling, belong to positioning navigation technical field. BACKGROUND

[0002] The pulse ultra-wideband (UWB) positioning system realizes distance measurement and position estimation by receiving the nanosecond-level narrow pulse transmitted by the transmitter and demodulating the precise position of the pulse, and has the characteristics of high time-domain resolution and strong multipath resolution capability. The UWB positioning system can provide high-precision positioning service in the environment where satellite navigation signals cannot cover, and has been widely used in indoor, underground and other areas. It has the advantages of low power consumption, low cost and strong penetration ability, but it also has some defects. (1) The ultra-wideband channel access mechanism is complex, and it is difficult for the terminal in deep sleep to realize fast wake-up and channel access. (2) The number of users of a single base station is limited. Since the UWB positioning system adopts time division system, the number of users is limited by the length of the signal frame, and the training sequence for channel impulse response (CIR) estimation in the signal frame limits the minimum length of the signal frame.

[0003] Based on the integrated design idea of navigation and communication, the narrowband communication signal and the ultra-wideband positioning signal are deeply coupled, the mature narrowband communication channel access technology is used to realize the fast wake-up and channel access of the UWB terminal, the same clock source is used for the two, the carrier frequency offset estimation of the UWB signal can be realized by using the narrowband communication signal, and the UWB signal receiving sensitivity is improved. At the same time, through the transmission of CIR information, navigation text and time slot allocation information by narrowband communication, the ranging frame length of UWB signal can be reduced, the base station time slot occupied by ranging can be shortened, and the user capacity of base station can be improved.

[0004] The research on the ultra-wideband positioning signal transmission method based on the tight coupling of narrowband communication signals is still in its early stages. The patents "Receiver for use in an ultra-wideband communication system" (Patent No. 201180055507.1) and "Ultra-wideband preamble receiver and receiving method thereof" (Patent No. 202010258433.2) mainly give the receiving method and device of UWB signal, and do not involve the assistance of narrowband signal. The patent "Method and device for generating integrated communication and navigation signal" (Patent No. 201811102234.1) gives a satellite navigation communication integrated method based on OFDMA system, which superimposes CDMA positioning signal on OFDMA signal to form an integrated communication and navigation signal, but it belongs to the field of satellite navigation and does not involve UWB signal. So far, there is no ultra-wideband positioning signal transmission method based on the tight coupling of narrowband communication signals. SUMMARY

[0005] The application aims to provide a UWB positioning signal transmission method tightly coupled with a narrowband communication signal, based on which a communication-assisted UWB positioning signal is designed and transmitted, so as to improve the user capacity of the UWB positioning system, realize fast channel access and terminal wakeup, improve the user capacity of the UWB positioning base station, and improve the UWB terminal receiving sensitivity.

[0006] The technical scheme adopted by the application is as follows:

[0007] A UWB positioning signal transmission method tightly coupled with a narrowband communication signal comprises the following steps:

[0008] Step 1: A narrowband-assisted UWB base station transmits a narrowband communication signal to wake up a narrowband-assisted UWB node, and the UWB node performs initialization and channel access after being woken up, and initiates communication and positioning request to the UWB base station by using the narrowband communication channel.

[0009] Step 2: The UWB base station sends UWB measurement frame time slot allocation information to the UWB node by using the narrowband communication channel, and the slot length is composed of the length of the UWB positioning measurement frame plus a certain protection interval.

[0010] Step 3: According to the time slot agreed upon by the narrowband communication, the UWB base station sends a UWB positioning measurement frame with a training sequence to the UWB node by using the UWB channel.

[0011] Step 4: After receiving the UWB positioning measurement frame, the UWB node demodulates the UWB positioning measurement frame, obtains the channel impulse response (CIR) estimation and carrier frequency offset by using the training sequence, and sends them to the UWB base station through the narrowband communication channel, and simultaneously sends a UWB positioning measurement frame without a training sequence to the UWB base station by using the UWB channel according to the time slot agreed upon by the narrowband communication.

[0012] Step 5: The UWB base station receives and demodulates the UWB positioning measurement frame sent by the UWB node by using the CIR estimation information and the carrier frequency offset estimation value, and calculates the distance between the UWB base station and the UWB node by using a two-way ranging algorithm.

[0013] Further, the narrowband communication signal and the UWB positioning measurement frame share the same clock source.

[0014] Further, the training sequence in the UWB positioning measurement frame with a training sequence in step 3 is a certain number of narrow pulses known by both the transmitter and the receiver, and adopts an OOK or BPSK pulse position fixed modulation mode; the information frame contains the transmission time, source address, destination address, three-dimensional coordinates of the base station, and the number of target nodes.

[0015] Further, the information in the UWB positioning measurement frame without training sequence in step 4 includes: time difference from receiving the UWB positioning measurement frame with training sequence to transmitting the UWB positioning measurement frame without training sequence, source address, destination address and return time, and the data is transmitted in the form of increasing physical layer load data.

[0016] The application proposes a UWB positioning signal transmission method tightly coupled with narrowband communication signals, which can realize the functions of integrated ranging, positioning and security authentication of narrowband communication and UWB positioning.

[0017] The application has the following advantages:

[0018] 1) The application realizes the fast wake-up and channel access of the UWB terminal by deeply coupling the narrowband communication signal and the ultra-wideband positioning signal, and by using the mature narrowband communication channel access technology;

[0019] 2) The application can realize the carrier frequency offset estimation of the UWB signal by using the narrowband communication signal, and improve the UWB signal receiving sensitivity by using the same clock source for UWB and narrowband communication;

[0020] 3) The application can reduce the ranging frame length of the UWB signal by transmitting the CIR information, carrier frequency offset, time slot allocation and other data of the UWB channel through the narrowband communication, thereby shortening the base station time slot occupied by the ranging, and improving the user capacity of the base station. BRIEF DESCRIPTION OF DRAWINGS

[0021] The drawings of the application are intended to show the general characteristics of the methods, structures and / or materials used in the specific exemplary embodiments according to the application, and to supplement the description in the specification. The drawings of the application should not be interpreted as limiting or restricting the scope of values or attributes covered by the exemplary embodiments according to the application.

[0022] Figure 1 It is a narrowband assisted UWB signal ranging flowchart of the application;

[0023] Figure 2 It is a UWB positioning measurement frame structure example with training sequence of the application;

[0024] Figure 3 It is a UWB positioning measurement frame structure example without training sequence of the application. DETAILED DESCRIPTION

[0025] The advantages and effects of the present application can be fully understood by those skilled in the art from the description of the specific embodiments. The present application can also be implemented or applied in different specific embodiments, and the details in the description can be applied based on different views, with various modifications or changes without departing from the general design idea of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. The exemplary embodiments of the present application can be implemented in various forms, and should not be interpreted as being limited to the specific embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application complete and complete, and to fully convey the technical solutions of the exemplary embodiments to those skilled in the art.

[0026] As shown in Figure 1 The UWB positioning signal transmission method designed based on the present application is combined with narrowband communication in the form of a figure. The narrowband communication method here can be a mature communication means such as Bluetooth, Wi-Fi, Zigbee, 2G / 3G / 4G / 5G, or a self-designed non-standard communication signal. As long as it has communication transmission capability and has a relatively mature channel access and carrier estimation algorithm, it can be used as the narrowband communication signal referred to in the present patent. The specific process includes:

[0027] Step 1: Narrowband-assisted UWB base station A transmits narrowband communication signals to wake up narrowband-assisted UWB node B. Node B completes initialization and channel access, and initiates communication and positioning request to base station A using the narrowband communication channel.

[0028] Step 2: Base station A sends UWB measurement frame time slot allocation information to node B using the narrowband communication channel. The time slot length is composed of the length of the UWB positioning measurement frame plus a certain guard interval. It is worth noting that the above process can occur in the form of base station broadcast, that is, base station A can wake up multiple nodes at the same time.

[0029] Step 3: According to the time slot agreed upon by base station A and node B using narrowband communication, base station A sends a UWB positioning measurement frame with a training sequence to node B using the UWB channel;

[0030] Step 4: Node B receives and demodulates the UWB positioning measurement frame, and uses the training sequence to give the channel impulse response (CIR) estimate and carrier frequency offset, and uses the narrowband communication channel to send the CIR estimate information and carrier frequency offset estimate to base station A. According to the reciprocity of the channel, the CIR information can also be used by base station A within a certain time; at the same time, according to the agreed time slot, node B sends a UWB positioning measurement frame without training sequence to base station A, which occupies a smaller time slot.

[0031] Step 5: Base station A receives and demodulates the ranging frame sent by Node B directly using the CIR information and the carrier frequency shift estimate. Then it calculates the distance between base station A and B using the two-way ranging algorithm.

[0032] After the ranging is completed, base station A can continue to communicate or range with other nodes according to the above process. Node B can also continue to communicate or range with other base stations according to the above process.

[0033] Figure 2 An example of the UWB positioning measurement frame with training sequence described in step 3 is shown, where the training sequence is a full "1" sequence of length 128, and each "1" represents a UWB narrow pulse. The frame start delimiter is used to indicate the start of the data frame, and other information includes time information, source address, base station three-dimensional coordinates, target node number and node address, etc.

[0034] Figure 3 An example of the UWB positioning measurement frame structure without training sequence described in step 4 is shown. The information frame of the UWB positioning measurement frame without training sequence contains the time difference from receiving the UWB positioning measurement frame with training sequence to transmitting the UWB positioning measurement frame without training sequence, source address, destination address and return time, and transmits data in the form of increasing physical layer payload data. It can be seen that, since there is no training sequence, the frame length is greatly reduced, and the base station time slot occupied is smaller, thereby improving the base station user capacity.

Claims

1. A method of transmitting an ultra-wideband positioning signal that is tightly coupled with a narrowband communication signal, characterized by, Comprising the following steps: Step 1: Narrowband assisted UWB base station transmits narrowband communication signal to wake up narrowband assisted UWB node, and the UWB node performs initialization and channel access after being woken up, and initiates communication and positioning request to the UWB base station by using the narrowband communication channel; Step 2: The UWB base station sends UWB measurement frame time slot allocation information to the UWB node by using the narrowband communication channel, and the time slot length is composed of the length of the UWB positioning measurement frame plus a certain protection interval; Step 3: According to the time slot agreed by the narrowband communication, the UWB base station sends UWB positioning measurement frame with training sequence to the UWB node by using the UWB channel; wherein the training sequence in the UWB positioning measurement frame with training sequence is a certain number of narrow pulses known by both the transmitter and the receiver, and the OOK or BPSK pulse position fixed modulation mode is adopted; the information frame contains transmission time, source address, destination address, three-dimensional coordinates of the base station and target node number; Step 4: After receiving the UWB positioning measurement frame, the UWB node demodulates and obtains channel impulse response (CIR) estimation and carrier frequency offset by using the training sequence, and sends them to the UWB base station through the narrowband communication channel, and at the same time, according to the time slot agreed by the narrowband communication, the UWB node sends UWB positioning measurement frame without training sequence to the UWB base station by using the UWB channel; wherein the information frame of the UWB positioning measurement frame without training sequence contains the time difference from receiving the UWB positioning measurement frame with training sequence to transmitting the UWB positioning measurement frame without training sequence, source address, destination address and return time, and data is transmitted in the form of increasing physical layer load data; Step 5: The UWB base station receives and demodulates the UWB positioning measurement frame sent by the UWB node by using the CIR estimation information and carrier frequency offset estimation value, and calculates the distance between the UWB base station and the UWB node by using the two-way ranging algorithm.

Images