A positioning method for integrated communication and navigation signals based on RSMA

Abstract

The invention relates to the field of communication and navigation technology, and specifically discloses a positioning method for a communication and navigation integrated signal based on RSMA, wherein a navigation satellite is used to perform time synchronization on a base station, and the base station obtains navigation and positioning information required by a user terminal; RSMA encoding is performed on the information at a transmitting end of the base station to generate a communication and navigation integrated signal, including a public stream and a private stream; the transmitting end of the base station distributes the power of the public stream and the private stream according to the power of the public stream and the private stream, and broadcasts the communication and navigation integrated signal to the user terminal; the user terminal receives the communication and navigation integrated signal and obtains required positioning information; the user terminal feeds back the channel state information in the private stream in the received communication and navigation integrated signal to the base station, and the base station adjusts the power distribution ratio of the public stream and the private stream according to the fed-back CSI information, and broadcasts the communication and navigation integrated signal to the corresponding user terminal again; the user terminal demodulates the received corresponding private stream to obtain required communication information.

Description

Technical Field

[0001] The present invention relates to the technical field of communication and navigation, and in particular to a positioning method for communication and navigation integrated signals based on RSMA. Background Art

[0002] In the era of the Internet of Everything, seamless, accurate, reliable, and intelligent spatiotemporal information has become the core foundation for national security, economic construction, and the development of a smart society. However, satellite navigation systems have low landing power and are easily shielded. There are blind spots in urban canyons and tunnels, which requires deep integration of communication and navigation. The integration of communication and navigation can achieve different degrees of integration at the signal level and the information level. For navigation-enhanced communication, the communication system uses navigation and positioning information to assist in optimizing the network and improve communication performance. For communication-enhanced navigation, the navigation system uses enhanced information transmitted by communication to achieve performance improvements such as accuracy and anti-interference capabilities. Wireless communication base stations have a wide coverage range and low deployment costs. Using wireless communication systems to enhance navigation systems has become a research hotspot. How to deeply integrate communication and navigation signals and broadcast them using wireless communication systems has become a key research topic.

[0003] The existing time-code orthogonal frequency division multiplexing (TC-OFDM) signal system uses communication base stations to broadcast integrated communication and navigation signals to achieve seamless indoor and outdoor positioning. This method improves positioning accuracy, but does not improve transmission efficiency at the communication transmission level. In addition, the navigation signal is hidden in the communication signal in an embedded manner, and the two will cause certain interference. Therefore, it is necessary to seek an efficient integrated communication and navigation signal system that is suitable for 5G and 6G standards. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a positioning method for integrated communication and navigation signals based on RSMA. By integrating the communication and navigation signals in terms of system and waveform, the wireless communication system can be used to achieve navigation enhancement in navigation satellite denial areas, improve spectrum utilization efficiency, reduce interference in communication and navigation signal fusion, achieve the integration of communication and navigation functions, save construction costs, and improve the effectiveness of the Internet of Everything.

[0005] The technical solution adopted by the present invention is: a positioning method for integrated communication and navigation signals based on RSMA, comprising:

[0006] Step S01: using navigation satellites to synchronize the timing of a base station, and the base station obtains navigation and positioning information required by a user terminal;

[0007] Step S02: using the base station to perform RSMA encoding on the information to generate a communication and navigation integrated signal, wherein the communication and navigation integrated signal includes a public stream and a private stream;

[0008] Step S03: the transmitting end of the base station allocates the power of the public flow and the private flow according to the power of the public flow and the private flow, and broadcasts the communication and navigation integrated signal to the user end;

[0009] Step S04: the user terminal receives the communication and navigation integrated signal, and first demodulates the public stream therein using SIC to obtain the required positioning information;

[0010] Step S05: the user terminal feeds back the channel state information of the private stream in the received communication and navigation integrated signal to the base station, and the base station adjusts the power allocation ratio of the public stream and the private stream according to the CSI information in the fed-back private stream, and broadcasts the communication and navigation integrated signal to the corresponding user terminal again;

[0011] Step S06: The user end demodulates the received corresponding private stream to obtain required communication information.

[0012] Preferably, the user terminal information in step S01 includes navigation positioning information.

[0013] Preferably, the RSMA encoding process in step S02 includes:

[0014] The positioning information is used as a public message, and all public messages are encoded into a public stream using a codebook shared by the intended users;

[0015] The communication information is regarded as a private message, and each private message is encoded into a private stream using an independent code book.

[0016] Preferably, the communication and navigation integrated signal of the base station transmitting end in step S03 is represented as:

[0017] ;

[0018] in, For base station The transmitter signal; For base station Precoder direction of the broadcasted common stream; For base station The first Precoder direction for each private stream; For base station The power allocated to the public stream; For base station Broadcast to The power of the private stream; For base station Broadcast public stream signals; For base station Broadcast to Private stream signal.

[0019] Preferably, the communication and navigation integrated signal received by the user terminal in step S04 is represented as:

[0020] ;

[0021] in, for The receiving end receives the base station signal; For base station arrive The channel gain of For base station The transmitter signal; for Obey in the channel Additive white Gaussian noise.

[0022] Preferably, in step S04, the user terminal decodes the public stream and regards the private stream as noise.

[0023] Preferably, the signal-to-noise ratio of the private flow to the public flow is expressed as:

[0024] ;

[0025] in, For base station The power allocated to the public stream; For base station arrive The channel gain of For base station Precoder direction of the broadcasted common stream; For base station Broadcast to The power of the private stream; For base station The first Precoder direction for each private stream; for The noise power.

[0026] Preferably, the power of the private stream in step S05 is adjusted according to the channel status of different users.

[0027] Preferably, in step S06, the user end decodes its corresponding private stream and regards other private streams as noise.

[0028] Preferably, the signal-to-noise ratio of the other private streams to the corresponding private stream is expressed as:

[0029] ;

[0030] in, For base station Broadcast to The power of the private stream; For base station arrive The channel gain of For base station The first Precoder direction for each private stream; For base station Broadcast to The power of the private stream; For base station The first Precoder direction for each private stream; for The noise power.

[0031] Beneficial effects of the above technical solution:

[0032] By using RSMA multiple access technology, the spectrum utilization efficiency is improved, so that when the communication base station is used to enhance the navigation function, the deployment cost of the integrated communication and navigation base station is controlled, which has practical value for the standardization construction of 5G and 6G. Reduce the interference between the integrated communication and navigation signals. By using the RSMA multiple access method, SIC demodulation is used at the receiving end to flexibly handle the relationship between the communication signal and the navigation signal. It has strong robustness and wide application scenarios. As long as the communication base station can receive the navigation signal for timing synchronization, the positioning function can also be realized in urban canyons and areas with weak positioning signals. It provides a new solution for signal fusion and power allocation between communication and navigation users. By adjusting the power allocation ratio and encoding method of the public and private streams of RSMA, the communication information can feedback the channel state information to the base station. The base station dynamically adjusts the strategy of broadcasting the communication and navigation signal through the feedback CSI, so as to more efficiently realize the transmission of the integrated communication and navigation signal and improve the spectrum utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A flow chart of communication and navigation integrated signal positioning based on RSMA provided by one embodiment of the present invention;

[0034] Figure 2 A schematic diagram of positioning based on a communication base station provided by an embodiment of the present invention;

[0035] Figure 3 Schematic diagram of RSMA concept provided for one embodiment of the present invention

[0036] Figure 4 A schematic diagram of RSMA encoding and demodulation provided by an embodiment of the present invention;

[0037] Figure 5 A schematic diagram of TOA positioning provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The following is a further detailed description of the implementation methods of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0039] The terms "first", "second", etc. (if any) in the specification and claims are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0040] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0041] Embodiment 1

[0042] An embodiment of the present invention provides a positioning method for integrated communication and navigation signals based on RSMA, with the purpose of two-dimensional positioning of users, and the implementation object is a user in a navigation satellite denied area, including: step S01: using a navigation satellite to synchronize the timing of a base station, and the base station obtains the navigation positioning information required by the user terminal;

[0043] Step S02: using the base station to perform RSMA encoding on the information to generate a communication and navigation integrated signal, wherein the communication and navigation integrated signal includes a public stream and a private stream;

[0044] Step S03: the transmitting end of the base station allocates the power of the public flow and the private flow according to the power of the public flow and the private flow, and broadcasts the communication and navigation integrated signal to the user end;

[0045] Step S04: the user terminal receives the communication and navigation integrated signal, and first demodulates the public stream therein using SIC to obtain the required positioning information;

[0046] Step S05: the user terminal feeds back the channel state information of the private stream in the received communication and navigation integrated signal to the base station, and the base station adjusts the power allocation ratio of the public stream and the private stream according to the CSI information in the fed-back private stream, and broadcasts the communication and navigation integrated signal to the corresponding user terminal again;

[0047] Step S06: The user end demodulates the received corresponding private stream to obtain required communication information.

[0048] The specific steps are as follows:

[0049] like Figure 1 As shown in the figure, the base station is first synchronized with the navigation satellite, and the base station obtains the navigation and positioning information required by the user. The wireless communication base station receives the positioning and navigation signals from the GPS satellite and the Beidou satellite through the timing receiving module, and tames the local atomic clock to provide high-precision timing for the ground base station, avoiding the synchronization error between base stations during TOA positioning, as shown in the figure. Figure 2 Then the base station transmitter uses the navigation positioning information as a public message and the communication information as a private message, and encodes each public message into a public stream using a codebook shared by the intended users, while each private message is encoded into a private stream using an independent codebook.

[0050] Base station, The user's downlink multiple input single output (MISO) system has a base station antenna number of .

[0051] like Figure 3 As shown, for the base station The transmitter has a public stream with A private stream, The flow matrix s n = [ s c , n , s 1 , n , ..., s k , n ] T ∈ ℂ ( K + 1 ) × 1 All flows are first allocated power. is the power of the public flow, For base station Assigned to The power of the private stream is then passed through the precoding matrix p n = [ p c , n , p 1 , n , … , p k , n ] (including direction and power) for linear precoding. Then the base station The transmitter signal for:

[0052] (1)

[0053] in , Indicates base station The precoder direction of the public stream being broadcasted, , Indicates base station The first To simplify the model, it is assumed that different base stations are completely symmetrical, that is, the allocation ratio of public flows to private flows is the same for all base stations.

[0054] Right now: , ,and , .

[0055] Through power allocation, the resource allocation between navigation signals and communication signals can be reasonably adjusted to improve the service quality of users. Through linear precoding, the interference between navigation signals and communication signals, as well as the interference between communication signals of different users, can be reduced. The stream is broadcast through the antenna, and the receiving end receives and demodulates it. The whole process is as follows Figure 4 shown.

[0056] The basic received signal model is:

[0057] (2)

[0058] but The receiving end receives the base station The signal is:

[0059] (3)

[0060] in, express Obey in the channel Additive white Gaussian noise.

[0061] In a MISO system, each user is served by one receive antenna, while the base station is equipped with multiple transmit antennas. have antennas, from the base station arrive The channel gain can be expressed as a complex vector ,in Each element of , indicating that from the base station No. Antenna to The channel gain.

[0062] h k , n H = [ h k , 1 , n , h k , 2 , n , ..., h k , N T , n ] (4)

[0063] According to the properties of Rayleigh channel, for:

[0064] (5)

[0065] in, is an imaginary unit, , obey , so the total average power of the channel is:

[0066] E [ | h k , t , n | 2 ] = 1 (6)

[0067] All users on the receiving end decode the public stream message, and only the corresponding user can decode the private stream. First decode the public stream into , all private streams are considered as interference noise; by using SIC, the navigation positioning information, i.e., the public information, is re-encoded and subtracted from the received signal, so that the user Private stream Decode into corresponding communication information , other private flows are considered as noise; By streaming from the public Extract That is, positioning and timing information, and and Merge into To reconstruct the original message, Figure 4 shown.

[0068] Base Station Broadcast to In the signal, the interference of all private flows on the public flow is:

[0069] (7)

[0070] Without loss of generality, assume E [ | s c 2 | ] = E [ | s k 2 | ] = 1 , ∀ k , then the base station Public streams broadcast to The corresponding signal-to-noise ratio (SINR) is expressed as:

[0071] (8)

[0072] in, express The channel noise power of other users is The noise caused by the private flow is:

[0073] (9)

[0074] The signal-to-noise ratio (SINR) corresponding to the private flow is:

[0075] (10)

[0076] Under the Gaussian signaling assumption, the public flow and The instantaneous rate that can be achieved by the private flow of is:

[0077] (11)

[0078] (12)

[0079] Get location information Then, the signal sending time point is obtained. , and record the arrival time The difference between the two time points is the signal flight time, so the base station arrive Signal flight time for:

[0080] (13)

[0081] The signal travels at about the speed of light The product of the flight time and the speed of light is the base station and The measuring distance between :

[0082] (14)

[0083] According to the base station and ( ), then the actual distance between the base station and the user for:

[0084] (15)

[0085] So for , true distance With measuring distance Satisfy the following formula:

[0086] (16)

[0087] in, is the measurement noise, which has a mean of zero and a variance of Gaussian white noise, For base station Transmitter and The clock error of the receiving end. Assume that the base station and the user end have the same delay, both , written in matrix form:

[0088] (17)

[0089] in, d k = [ d k , 1 , d k , 2 , ..., d k , N ] T , D k = [ D k , 1 , D k , 2 , ..., D k , N ] ,

[0090] δ k = [ δ k , 1 , δ k , 2 , ..., δ k , N ] T ,for , it can be calculated The PDF is:

[0091] (18)

[0092] Formula (18) is rewritten as:

[0093] (19)

[0094] in, TOF k = [ TOF k , 1 , TOF k , 2 , ..., TOF k , N ] , θ k = [ x k , y k ] , the log-likelihood function of formula (19) is:

[0095] (20)

[0096] Right now:

[0097] (twenty one)

[0098] For two-dimensional positioning, assuming that the measurement noises are independent of each other, the Fisher information matrix is ​​a The diagonal matrix of , the partial derivative of the log-likelihood function is used to calculate the Fisher information matrix, and we get:

[0099] F 11 =− E [ ∑ n = 1 N ∂ 2 L ( TOF k , n | θ k ) ∂ 2 x k ] (twenty two)

[0100] F 22 =− E [ ∑ n = 1 N ∂ 2 L ( TOF k , n | θ k ) ∂ 2 y k ] (twenty three)

[0101] CRLB can be obtained from the inverse matrix of the Fisher information matrix, which is specifically expressed as:

[0102] (twenty four)

[0103] (25)

[0104] The lower bound shows the theoretical limit of positioning accuracy under given noise level and number of base stations and users. Figure 5 As shown, it is known base stations, we can obtain With the base station as the center and the distance between the base station and the user as the radius, a circular curve can be drawn. For two-dimensional positioning, when multiple base stations participate in positioning ( ), the intersection of the circles with multiple base stations as the center is the estimated location of the user .

[0105] When evaluating the positioning accuracy, you can use MSE to compare CRLB with MSE to get the positioning accuracy of the method. The mean square error MSE is:

[0106] MSE = E [ ( x k − x ^ k ) 2 + ( y k − y ^ k ) 2 ] (26)

[0107] At the same time, if Figure 1 As shown, when the receiving end demodulates the private information The CSI is fed back to the base station again. The base station adjusts the power between positioning information and communication information according to the CSI, adjusts the power ratio between private streams according to the channel status of different users, and broadcasts the integrated communication and navigation signal again, thereby improving positioning accuracy and user fairness and saving resources.

[0108] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A positioning method for integrated communication and navigation signals based on RSMA, characterized in that: include: Step S01: using navigation satellites to synchronize the timing of a base station, and the base station obtains navigation and positioning information required by a user terminal; Step S02: using the base station to perform RSMA encoding on the information to generate a communication and navigation integrated signal, wherein the communication and navigation integrated signal includes a public stream and a private stream; Step S03: the transmitting end of the base station allocates the power of the public flow and the private flow according to the power of the public flow and the private flow, and broadcasts the communication and navigation integrated signal to the user end; Step S04: the user terminal receives the communication and navigation integrated signal, and demodulates the public stream therein using SIC to obtain the required positioning information; Step S05: the user terminal feeds back the channel state information of the private stream in the received communication and navigation integrated signal to the base station, and the base station adjusts the power allocation ratio of the public stream and the private stream according to the CSI information in the fed-back private stream, and broadcasts the communication and navigation integrated signal to the corresponding user terminal again; Step S06: The user end demodulates the received corresponding private stream to obtain required communication information.

2. The positioning method of the communication and navigation integrated signal based on RSMA according to claim 1, characterized in that: The RSMA encoding process in step S02 includes: The positioning information is used as a public message, and all public messages are encoded into a public stream using a codebook shared by the intended users; The communication information is regarded as a private message, and each private message is encoded into a private stream using an independent code book.

3. The positioning method of the communication and navigation integrated signal based on RSMA according to claim 1 is characterized in that: The communication and navigation integrated signal of the base station transmitting end in step S03 is expressed as: Among them, x n is the transmitting end signal of base station n; The precoder direction of the common stream broadcast by base station n; is the precoder direction of the kth private stream broadcast by base station n; c is the power allocated to the public flow by base station n; pk ,n is the power of the private flow broadcast by base station n to User-k; s c,n sk is the public stream signal broadcast by base station n; ,n It is the private flow signal broadcast by base station n to User-k.

4. The positioning method of the communication and navigation integrated signal based on RSMA according to claim 1, characterized in that: The communication and navigation integrated signal received by the user terminal in step S04 is represented as: Among them, yk ,n The receiving end of User-K receives the signal from base station n; is the channel gain from base station n to User-k; x n is the transmitting end signal of base station n; k Obey in the channel of User-k Additive white Gaussian noise.

5. The positioning method of the communication and navigation integrated signal based on RSMA according to claim 1 is characterized in that: In step S04, the user end decodes the public stream and regards the private stream as noise.

6. The positioning method of the communication and navigation integrated signal based on RSMA according to claim 5, characterized in that: The signal-to-noise ratio of the private flow to the public flow is expressed as: Among them, p c The power allocated to the public flow by base station n; is the channel gain from base station n to User-k; is the precoder direction of the common stream broadcast by base station n; j,n is the power of the private flow broadcast by base station n to User-j; N is the precoder direction of the jth private stream broadcast by base station n; k is the noise power of User-k.

7. The positioning method of the communication and navigation integrated signal based on RSMA according to claim 1, characterized in that: In step S05, the power of the private stream is adjusted according to the channel status of different users.

8. The positioning method of the communication and navigation integrated signal based on RSMA according to claim 1, characterized in that: In step S06, the user end decodes its corresponding private stream and regards other private streams as noise.

9. The positioning method of the communication and navigation integrated signal based on RSMA according to claim 8, characterized in that: The signal-to-noise ratio of the other private streams to the corresponding private stream is expressed as: Among them, p k,n is the power of the private flow broadcast by base station n to User-k; is the channel gain from base station n to User-k; is the precoder direction of the kth private stream broadcast by base station n; j,n is the power of the private flow broadcast by base station n to User-j; p j,n N is the precoder direction of the jth private stream broadcast by base station n; k is the noise power of User-k.

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