CN109870676A - Measurement method of performance limit of radar communication integrated system based on positioning estimation rate - Google Patents

Abstract

The invention discloses a method for measuring the performance limit of a radar communication integrated system based on a positioning estimation rate, which is applied to the field of radar technology. According to the prior art, when measuring the performance limit of a radar communication integrated system, there is only target distance information and no angle information. The present invention comprehensively considers the target distance information and angle information. First, the radar signal, communication signal and composite signal received by the receiver are modeled, and then according to the way of sharing the radar and communication spectrum in the radar communication integrated system , divide the situation of spectrum sharing into: traditional single sub-bandwidth, communication-independent sub-bandwidth and radar-independent sub-bandwidth, and then use the positioning estimation rate and communication rate to characterize the performance of radar function and communication function respectively, and finally use the positioning estimation rate and communication rate to characterize the performance of radar function and communication function. The theoretical derivation of the performance limit of the integrated radar communication system under different frequency band sharing modes is carried out, and the performance measurement of the integrated radar communication system is realized.

Description

Measurement method of performance limit of radar communication integrated system based on positioning estimation rate

technical field

The invention belongs to the technical field of radar, and particularly relates to a performance limit measurement technology of a radar communication integrated system.

Background technique

Modern radar equipment has multiple functions such as target detection, equipment deployment and sharing acquired information with other equipment. How to combine radar equipment with communication equipment to form a complete system to solve the problem of rational utilization of resources is an increasing research topic in recent years. Combining radar equipment and communication equipment to form an integrated system, how to solve the problem of rational utilization of resources has become one of the research hotspots of domestic and foreign experts.

Radar and communication spectrum sharing is one of the key researches to solve the shortage of spectrum resources and improve spectrum utilization. This is a very meaningful research topic, but the problem of mutual interference caused by the sharing of radar and communication spectrum, the development of the characterization method for the performance of the radar-communication integrated system and the theoretical research on the performance limit of the radar-communication integrated system are still very important. the problem of this study. In the document "Inner Bounds on Performance of Radar and Communications Co-Existence, IEEE Transactions on Signal Processing, vol.64, no.2, pp.464-474, 2015", the concept of radar estimation information rate is proposed, and the radar The system estimates the information rate and the communication rate of the communication system to deduce the achievable performance limit of the radar communication integrated system, but it only considers the time of arrival (TOA) of the beam, and does not consider the beam angle of arrival (Direction of Arrival). , DOA), that is, only the target distance information, no angle information. Judging from the published articles, there is no research on using the positioning estimation rate to measure the performance limit of the integrated radar communication system.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present invention proposes a method for measuring the performance limit of the integrated radar communication system based on the positioning estimation rate, which takes into account the joint information of the beam arrival time and the beam arrival angle, and realizes the integrated radar communication system under different frequency band sharing modes. Performance limit measurement.

The performance limit measurement method of the radar communication integrated system based on the positioning estimation rate, including:

S1, the receiving window simultaneously receives: radar signal, communication signal, composite signal;

S2. Spectrum sharing mode division: traditional independent sub-bandwidth mode, communication independent sub-bandwidth mode and radar independent sub-bandwidth mode;

In the traditional single subbandwidth mode, the total bandwidth is divided into two parts, one part is used for communication and the other part is used for radar; the two parts work without any interference in their respective subbands;

In the communication independent sub-bandwidth mode, the total bandwidth is divided into two parts, one part is only used for communication, which is called communication independent sub-bandwidth, and the other part is used for radar and communication at the same time, which is called mixed sub-bandwidth;

In the radar independent sub-bandwidth mode, the total bandwidth is divided into two parts, one part is only used for radar, which is called radar independent sub-bandwidth, and the other part is used for radar and communication at the same time, which is called mixed sub-bandwidth;

S3. Considering the joint information of beam arrival time and beam arrival angle, obtain the boundary expression of the positioning estimation rate representing the functional performance of the radar;

S4. Use the communication rate to characterize the performance of the communication function;

S5. Calculate the boundaries of the communication rate and the positioning estimation rate under different spectrum sharing modes in step S2, respectively.

Further, the process of obtaining the positioning estimation rate expression representing the radar functional performance described in step S3 is:

A1, according to the radar signal received in step S1, obtain its probability density function about τ and θ; wherein, τ represents the beam arrival time, and θ represents the beam arrival angle;

A2. Obtain the corresponding Fisher information matrix according to the probability density function of step A1;

A3. Follow the Fisher information matrix of step A2 to obtain the Clamello bound of the beam arrival time and the Cramerlot bound of the beam arrival angle;

A4. Obtain the upper bound expression of the positioning estimation rate according to the Clamello bound of the beam arrival time and the Clamello bound of the beam arrival angle. Step A4 is specifically:

A41. The positioning estimation rate is:

Among them, h _rs represents the entropy of the received signal, h _est represents the estimated entropy, and T _pri represents the pulse repetition interval;

A42. Obtain the minimum mean square error of the positioning estimator according to the Clamello bound of the beam arrival time and the Clamello bound of the beam arrival angle;

A43. According to the minimum mean square error of the positioning estimator, h _rs and h _est of the received radar signal are obtained respectively:

Among them, J _min represents the minimum mean square error of the positioning estimator, and n _pro represents the rest of the noise except the estimated noise;

A44. Bring the h _rs and h _est obtained in step A43 into the expression in step A41, and obtain the upper bound expression of the positioning estimation rate as:

where T is the pulse width, γ is the signal-to-noise ratio,

Further, the communication rate expression in step S4 is:

Among them, B _c is the communication independent sub-bandwidth, h is the communication signal propagation gain, κ is the Boltzmann constant, T ₀ is the absolute temperature of the communication system, and p _c is the communication power in the total bandwidth.

Further, in step S5, the boundaries of the communication rate and the positioning estimation rate under the traditional single sub-bandwidth mode are respectively:

Among them, α is the bandwidth adjustment factor, and 0≤α≤1, B is the bandwidth, _npro is the rest noise except the estimated noise, γ is the signal-to-noise ratio, B _r is the radar independent sub-bandwidth, δ is the duty cycle , T is the pulse width, N is the number of antenna elements, d is the distance between antenna elements, c is the speed of light, λ is the plane wave wavelength, p _r is the radar transmit power, and g is the propagation gain of the radar signal.

Further, the communication rate of the communication independent sub-bandwidth under the communication independent sub-bandwidth mode in step S5 is:

Among them, p _c,o is the communication power allocated in the communication independent sub-bandwidth in the communication independent sub-bandwidth mode.

Further, the communication rate of the mixed sub-bandwidth and the boundary calculation process of the positioning estimation rate under the communication independent sub-bandwidth mode in step S5 are:

B1. Use SIC to process the received composite signal in the mixed frequency band;

B2. The joint receiver first decodes the received communication signal;

B3. When the communication signal is decoded successfully, subtract it from the composite signal to obtain the radar signal without communication signal interference;

B4. Taking the radar signal in step B3 as interference, the communication rate in the mixed sub-bandwidth is obtained:

Among them, p _c,m is the communication power allocated in the mixed sub-bandwidth in the communication independent sub-bandwidth mode;

B5. Since the communication signal has been removed, according to the positioning estimation rate boundary expression in step S3, the positioning estimation rate boundary in the mixed sub-bandwidth is obtained as:

Further, the positioning estimation rate of the radar independent sub-bandwidth under the radar independent sub-bandwidth mode in step S5 is:

Among them, γ _r,o is the communication signal-to-noise ratio of the radar independent sub-bandwidth in the radar independent sub-bandwidth mode, and p _r,o is the radar power allocated in the radar independent sub-bandwidth mode in the radar independent sub-bandwidth mode.

Further, in step S5, the communication rate and positioning estimation rate boundary calculation process of the mixed sub-bandwidth under the radar independent sub-bandwidth mode is:

C1. Use SIC to process the received composite signal in the mixed frequency band;

C2. The joint receiver first decodes the received radar signal;

C3. When the radar signal is decoded successfully, subtract it from the composite signal to obtain a communication signal without radar signal interference;

C4. Use the communication signal in step C3 as interference to obtain the positioning estimation rate in the mixed sub-bandwidth:

Among them, γ _r,m is the communication signal-to-noise ratio of the mixed sub-bandwidth in the radar independent sub-bandwidth mode, and p _r,m is the radar power allocated in the mixed sub-bandwidth in the radar independent sub-bandwidth mode;

C5. Since the radar signal has been removed, according to the communication rate expression in step S4, the communication rate in the mixed sub-bandwidth is obtained:

Beneficial effects of the present invention: the present invention firstly models the radar signal, the communication signal and the composite signal received by the receiver, and then divides the frequency spectrum sharing situation according to the way of spectrum sharing between radar and communication in the integrated radar communication system. For three types, namely traditional single sub-bandwidth, communication-independent sub-bandwidth and radar-independent sub-bandwidth, the performance characterization method of radar communication integrated system is formulated, and the performance of radar function and communication function is characterized by positioning estimation rate and communication rate respectively. Finally, the performance limits of the radar communication integrated system under different spectrum sharing modes are theoretically derived by using the positioning estimation rate and the communication rate, so as to realize the measurement of the performance of the radar communication integrated system; the advantage of the present invention is that the beam arrival time ( TOA), beam angle of arrival (DOA) joint information, realizes the performance limit measurement of radar communication integrated system under different frequency band sharing modes; the method of the invention is suitable for civil military and other fields.

Description of drawings

FIG. 1 is a block diagram of the overall structure of the method provided by the present invention.

FIG. 2 is a structural block diagram of the present invention using the traditional ISB spectrum sharing mode.

FIG. 3 is a structural block diagram of the present invention adopting the CIB spectrum sharing mode.

FIG. 4 is a structural block diagram of the present invention using the RIB spectrum sharing mode.

FIG. 5 is a simulation result of the performance limit of the radar communication integrated system under three spectrum sharing modes of ISB, CIB and RIB in the specific embodiment of the present invention.

FIG. 6 is a simulation result of improving the communication rate performance of the CIB and RIB spectrum sharing modes compared to the ISB spectrum sharing mode in the specific embodiment of the present invention.

7 is a simulation result of improving the performance of the positioning estimation rate in the CIB and RIB spectrum sharing methods compared to the ISB spectrum sharing method in the specific embodiment of the present invention.

Detailed ways

In order to facilitate those skilled in the art to understand the technical content of the present invention, the content of the present invention will be further explained below with reference to the accompanying drawings.

The present invention mainly adopts the method of simulation experiment for verification, and all steps and conclusions are verified correctly on Matlab2014. The present invention will be further described in detail below with respect to specific embodiments.

Step 1: Receive signal modeling:

The receiving window simultaneously receives the radar signal z _r (t) and the communication signal z _c (t), and the composite signal is z(t) as:

z( _t )= _zr (t)+zc(t)(1)

Define the eigenvector a(θ) of the antenna:

a(θ)=[1,e ^{-j2πdcosθ/λ} ,...,e ^{-j2π(N-1)dcosθ/λ} ] ^T (2)

where d is the antenna element spacing, λ is the plane wave wavelength, θ is the DOA, and the received radar signal z _r (t) is given by:

Among them, pr represents the radar transmit power, _fr represents the carrier frequency of the radar signal, g represents the propagation gain of the radar signal, _{τ r represents the propagation delay time of the radar signal, φ r represents the} carrier phase caused by the propagation delay time, and satisfies φ _r = -2πf _r τ _r . n _r (t) is the Additive White Gaussian Noise (AWGN) with mean 0 and variance σ ² =κT _sys B, where κ is Boltzmann's constant, T _sys is the radar system noise temperature, and B is the bandwidth .

Mathematical expression of the received communication signal:

where f _c is the carrier frequency of the communication signal, s _c (t) is the equivalent communication baseband signal, h is the communication signal propagation gain, τ _c is the propagation delay time of the communication signal, φ _r is the carrier phase caused by the propagation delay , satisfying φ _c =-2πf _c τ _c .

Step 2: Spectrum sharing method division:

According to the way of frequency band sharing between radar and communication in the integrated radar communication system, the frequency spectrum sharing is divided into three categories, namely traditional isolated sub-band (ISB), traditional isolated sub-band (ISB) and traditional isolated sub-band (ISB). , CIB) and radar independent sub-band (radar isolated sub-band, RIB).

Step 2.1: Legacy Individual Subbandwidth:

In the ISB mode, the total bandwidth is divided into two parts, one part is used for communication, the other part is used for radar, the two parts of communication and radar work without any interference in their respective sub-bands.

Step 2.2: Communication Independent Subbandwidth:

In the CIB mode, the total bandwidth is divided into two parts, one part is only used for communication, which is called communication independent sub-bandwidth, and the other part is used for radar and communication at the same time, which is called mixed sub-bandwidth.

Step 2.3: Radar Independent Subbandwidth:

In RIB mode, the total bandwidth is divided into two parts, one part is only used for radar, which is called radar independent sub-bandwidth, and the other part is used for radar and communication at the same time, which is called mixed sub-bandwidth.

Step 3: Characterization of the radar communication integrated system:

Step 3.1: Performance Characterization of Radar Function:

Given the AWGN in equation (3), the probability density function (pdf) of the radar received signal z _r (t) with respect to τ and θ is:

Assuming that p(z;τ,θ) satisfies the "regular" condition, the corresponding fisher information matrix (FIM) can be obtained:

After some algebraic derivation, the Commodity Research Bureau (CRB) for TOA and DOA are:

Among them, γ represents the signal to noise ratio (Signal to noise ratio, SNR), represents the mean square effective bandwidth and satisfies:

Defining Δτ and Δθ as the estimation errors of τ and θ, respectively, the positioning estimation can be expressed as:

The minimum mean squared error (MMSE) J _min of the positioning estimator is:

According to the incentives of estimated entropy and random process entropy to the communication rate, the positioning estimation rate is defined as:

where T _pri =T/δ represents the pulse repetition interval, T represents the pulse width, δ represents the duty cycle, and h _rs and h _est represent the received signal entropy and estimated entropy, respectively:

where _npro is the rest of the noise except the estimated noise. From equations (13) and (14), the upper bound of the positioning estimation rate can be obtained as:

in,

Step 3.2: Performance characterization of the communication function:

The communication rate R _com is used to measure the performance of the communication function. The greater the communication rate, the greater the maximum number of bits that can be transmitted on the channel per unit time, and the stronger the information transmission capability. According to Shannon's theorem:

Among them, T ₀ represents the absolute temperature of the communication system, and B _c represents the bandwidth of the communication channel.

Step 4: Analysis of the performance limit of the radar communication integrated system under different spectrum sharing methods:

Step 4.1: Analysis of the performance limit of the radar communication integrated system in the ISB mode;

In the ISB mode, let the radar bandwidth be B _r and the communication bandwidth be B _c .

B _c =αB,B _r =(1-α)B (17)

Among them, α (0≤α≤1) is the bandwidth adjustment factor, B _c is the communication independent sub-bandwidth, and B _r is the radar independent sub-bandwidth.

According to Equation (15) and Equation (16), the corresponding communication rate R _com and positioning estimation rate are:

Step 4.2: Analysis of performance limit of radar communication integrated system in CIB mode:

In the CIB mode, let the communication independent sub-bandwidth be B _c , the mixed sub-bandwidth be B _mix , and the water-filling method is used to distribute the communication power. Given the bandwidth adjustment factor α (0≤α≤1), the mathematical expressions of the two sub-bandwidths are:

B _c =αB,B _mix =(1-α)B (20)

Step 4.2.1: Communication rate of communication independent subbands

According to equation (16), the communication rate of the communication independent sub-bandwidth can be obtained:

Among them, p _c,o is the communication power allocated in the communication independent sub-bandwidth.

Step 4.2.2: Communication rate and location estimation rate for mixed subbands:

The SIC is used to process the received composite signal in the mixed frequency band, and the joint receiver first decodes the received communication signal. Once the communication signal has been decoded, it is subtracted from the composite signal to obtain a radar signal free of interference from the communication signal.

Considering the radar signal as interference, the communication signal-to-interference ratio (SIR) of the mixed sub-bandwidth is:

Among them, p _c,m is the communication power allocated in the mixed sub-bandwidth.

According to equation (16), the communication rate in the mixed sub-bandwidth The mathematical expression is:

Since the communication signal has been removed, according to Equation (15), the positioning estimation rate R _est in the mixed sub-bandwidth is:

Step 4.2.3: Communication Power Allocation:

The water injection method is used to distribute the communication power, and the values of pc _,o and pc _,m are optimized to achieve the maximum communication rate. The corresponding Lagrangian function is:

where λ is the Lagrange multiplier. By solving the KKT point of the Lagrangian function, the value range of p _{c, o} can be obtained as:

Because p _c,o +p _c,m =p _c , p _c,m ≥ 0, the constraint relationship between p _c and p _r is further obtained as:

Step 4.3: Analysis of the performance limit of the radar communication integrated system in RIB mode:

In the RIB mode, let the radar independent sub-bandwidth be B _r and the mixed sub-bandwidth be B _mix . Given the bandwidth adjustment factor α (0≤α≤1), the mathematical expressions of the two sub-bandwidths are:

B _r =αB,B _mix =(1-α)B (28)

Step 4.3.1: Position Estimation Rates for Radar Independent Subbandwidths

For the radar signal in the radar independent sub-band, which is not interfered by the communication signal, the signal-to-noise ratio is:

where _pr,o is the radar power allocated in the radar independent sub-bandwidth. According to equation (15), the corresponding positioning estimation rate is:

Step 4.3.2: Communication rate and location estimation rate for mixed subbands:

The SIC is used to process the received composite signal in the mixed frequency band, and the joint receiver first decodes the received radar signal. Once the radar signal is successfully decoded, it is subtracted from the composite signal to obtain a communication signal free of radar signal interference.

Considering the communication signal as the interference of the radar signal, the radar signal-to-interference ratio (SIR) in the mixed sub-band is:

Among them, _pr,m is the radar power allocated in the mixed sub-bandwidth. According to equation (15), the corresponding positioning estimation rate is:

Since the radar signal has been removed, according to Equation (16), the mathematical expression of the communication rate R _com in the mixed sub-bandwidth is:

Step 4.3.3: Radar Power Allocation:

The same as the principle of communication power distribution, the water injection method is used to distribute the radar power, and the values of _pr,o and _pr,m are optimized to maximize the positioning estimation rate.

The effect of the present invention is further illustrated by the following simulation test:

Simulation scenario: Assuming that the target cross-sectional area is known, the received power of the receiver follows a typical propagation loss model, that is, the received signal power is proportional to r- ⁿ , where r is the radar detection distance or communication transmission distance, and n is the path loss index. The path loss exponents for radar and communications are set to 4 and 2, respectively. The working parameters of the radar communication integrated system are shown in Table 1.

The simulation results of the performance limit of the radar communication integrated system under the three spectrum sharing modes of ISB, CIB and RIB are shown in Fig. 5.

Compared with the ISB spectrum sharing method, the CIB and RIB spectrum sharing methods improve the communication rate performance and the simulation results are shown in Figure 6.

Compared with the ISB spectrum sharing method, the CIB and RIB spectrum sharing methods improve the performance of the positioning estimation rate and the simulation results are shown in Figure 7.

Table 1 Working parameters of radar communication integrated system

parameter Numerical value Bandwidth (B) 8MHz Wavelength (λ) 0.3m Absolute temperature (T₀) 290K Radar detection power (p_r) 10KW Radar detection distance (r_r) 10km Radar detection antenna gain (g) 1000 Antenna element spacing (d) 0.3m Communication transmit power (p_c) 50W Communication transmission distance (r_c) 10km Number of Antenna Units (N) 5 Pulse width (T) 20μs Target cross-sectional area (σ) 2m² Pulse duty cycle (δ) 0.05 DOA π/2

Figure 5 plots the performance boundaries of the radar communication integrated system under the three spectrum sharing modes of ISB, CIB and RIB. The external constraints indicate that the maximum positioning estimation rate of 7890bit/s and the maximum communication data rate of 1.445×10 ⁷ bit/s can be achieved by allocating the total bandwidth to communication or radar under the three spectrum sharing methods, respectively, as shown in point A in Figure 4. and point D. It can be seen that the performance limit of the traditional ISB mode is lower than that of the RIB mode and the CIB mode. Among them, at point B, since all bandwidths are allocated to radar, the communication rate in ISB and RIB mode is 0 bit/s, but since radar and communication share all bandwidth in CIB mode, the communication rate can still reach 4.301×10 ⁶ bit/s. Similarly, at point C, since all bandwidths are allocated to communication, the positioning estimation rate in ISB and CIB mode is 0bit/s, but since radar and communication share all bandwidth in RIB mode, the positioning estimation rate can still reach 2591bit /s.

Figure 6 plots the improvement of the communication rate performance of the CIB and RIB spectrum sharing methods compared to the ISB spectrum sharing method. It can be seen that, compared with the ISB mode, the performance of the communication rate in the CIB and RIB modes is significantly improved. Among them, the performance improvement effect is the most obvious in the CIB mode. When the communication rate is 4.301×10 ⁶ bit/s, the positioning estimation rate can reach the maximum value.

Figure 7 plots the performance improvement of the positioning estimation rate of the CIB and RIB spectrum sharing methods compared to the ISB spectrum sharing method. It can be seen that compared with the ISB method, the performance of the positioning estimation rate in the CIB and RIB methods is significantly improved. Among them, the performance improvement effect is the most obvious in the RIB mode. When the positioning estimation rate is 2591bit/s, the communication rate can reach the maximum value.

In conclusion, the present invention can well measure the performance limit of the radar communication integrated system.

Those of ordinary skill in the art will appreciate that the embodiments described herein are intended to assist readers in understanding the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific statements and embodiments. Various modifications and variations of the present invention are possible for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims (9)

1. The method for measuring the performance limit of the radar communication integrated system based on the positioning estimation rate is characterized by comprising the following steps:

s1, receiving the signals by the receiving window at the same time: radar signals, communication signals, composite signals;

s2, the spectrum sharing mode is divided into: a traditional independent sub-bandwidth mode, a communication independent sub-bandwidth mode and a radar independent sub-bandwidth mode;

under the traditional independent sub-bandwidth mode, the total bandwidth is divided into two parts, one part is used for communication, and the other part is used for radar; the two parts work in respective sub-frequency bands without any interference;

under the communication independent sub-bandwidth mode, the total bandwidth is divided into two parts, one part is only used for communication and is called communication independent sub-bandwidth, and the other part is simultaneously used for radar and communication and is called mixed sub-bandwidth;

under the radar independent sub-bandwidth mode, the total bandwidth is divided into two parts, one part is only used for radar and is called radar independent sub-bandwidth, and the other part is simultaneously used for radar and communication and is called hybrid sub-bandwidth;

s3, obtaining a positioning estimation rate boundary expression representing radar function performance by considering the beam arrival time and the beam arrival angle joint information;

s4, representing the performance of the communication function by adopting the communication rate;

s5, calculating the communication rate and the estimated location rate boundary under different spectrum sharing modes in step S2.

2. The method for measuring performance limit of integrated radar communication system based on positioning estimation rate as claimed in claim 1, wherein the step S3 of obtaining the positioning estimation rate expression characterizing the radar function performance comprises:

a1, obtaining probability density functions of the radar signals received in the step S1 with respect to tau and theta; where τ represents the beam arrival time and θ represents the beam arrival angle;

a2, obtaining a corresponding snow information matrix according to the probability density function of the step A1;

a3, obtaining a Cramer-Rao bound of the arrival time of the wave beam and a Cramer-Rao bound of the arrival angle of the wave beam according to the Fisher-snow information matrix of the step A2;

a4, Cramer-Role bound according to beam arrival time, and Cramer-Role bound according to beam arrival angle; and obtaining an upper bound expression of the positioning estimation rate.

3. The method for measuring performance limit of radar communication integration system based on positioning estimation rate as claimed in claim 2, wherein step a4 specifically comprises:

a41, the positioning estimation rate is:

wherein h is_rsRepresenting the entropy of the received signal, h_estRepresenting the estimated entropy, T_priRepresenting a pulse repetition interval;

a42, obtaining the minimum mean square error of the positioning estimator according to the Cramer-Rao bound of the arrival time of the wave beam and the Cramer-Rao bound of the arrival angle of the wave beam;

a43, respectively obtaining h of the received radar signals according to the minimum mean square error of the positioning estimator_rsAnd h_est；

A44, h obtained in the step A43_rsAnd h_estAnd substituting the expression of the step A41 to update the expression of the positioning estimation rate.

4. The method of claim 3, wherein the communication rate expression of step S4 is as follows:

wherein, B_cDenotes the communication independent sub-bandwidth, h denotes the communication signal propagation gain, k is the boltzmann constant, T₀Indicating the absolute temperature, p, of the communication system_cRepresenting the communication power in the total bandwidth.

5. The method of claim 4, wherein the communication rate and the position estimation rate boundary in the conventional single sub-bandwidth manner in step S5 are respectively:

wherein α is a bandwidth adjustment factor, 0 is equal to or more than α is equal to or more than 1, B represents a bandwidth, n is equal to or more than 1_proRepresenting the remaining noise, except the estimated noise, gamma representing the signal-to-noise ratio, B_rRepresenting the radar independent sub-bandwidth, delta representing the duty cycle, T representing the pulse width,n denotes the number of antenna elements, d denotes the antenna element spacing, c denotes the speed of light, λ is the plane wave wavelength, p_rDenotes the radar transmission power, and g denotes the propagation gain of the radar signal.

6. The method for measuring performance limit of integrated radar communication system according to claim 5, wherein the communication rate of the communication independent sub-bandwidth in the communication independent sub-bandwidth manner in step S5 is:

wherein p is_c,oAnd the communication power distributed in the communication independent sub-bandwidth mode.

7. The method of claim 6, wherein the boundary calculation process of the communication rate and the position estimation rate of the mixed sub-bandwidth in the communication independent sub-bandwidth mode in step S5 is as follows:

b1, processing the received composite signal in the mixed frequency band by using SIC;

b2, the joint receiver firstly decodes the received communication signal;

b3, when the communication signal is successfully decoded, subtracting the communication signal from the composite signal to obtain a radar signal without communication signal interference;

b4, using the radar signal in the step B3 as interference, and obtaining the communication rate in the mixed sub-bandwidth as:

wherein p is_c,mCommunication power allocated in the mixed sub-bandwidth in the communication independent sub-bandwidth mode;

b5, since the communication signal has been removed, according to the positioning estimation rate boundary expression of step S3, the positioning estimation rate boundary in the mixed sub-bandwidth is obtained as:

8. the method for measuring performance boundary of radar-communication integrated system according to claim 4, wherein the positioning estimation rate of radar independent sub-bandwidth in radar independent sub-bandwidth mode in step S5 is:

wherein, γ_r,oFor the communication signal-to-noise ratio, p, of the radar independent sub-bandwidth in the radar independent sub-bandwidth mode_r,oAnd allocating the radar power in the radar independent sub-bandwidth mode.

9. The method for measuring performance boundary of radar communication integration system based on positioning estimation rate as claimed in claim 8, wherein the boundary calculation procedure of communication rate and positioning estimation rate of mixed sub-bandwidth in radar independent sub-bandwidth mode in step S5 is as follows:

c1, processing the received composite signal in the mixed frequency band by using SIC;

c2, the joint receiver firstly decodes the received radar signal;

c3, when the radar signal is decoded successfully, subtracting the radar signal from the composite signal to obtain a communication signal without radar signal interference;

c4, using the communication signal in the step C3 as interference, obtaining the positioning estimation rate in the mixed sub-bandwidth:

wherein, γ_r,mCommunication signal-to-noise ratio, p, for mixed sub-bandwidths in radar independent sub-bandwidth mode_r,mAllocating radar power in the mixed sub-bandwidth in a radar independent sub-bandwidth mode;

c5, since the radar signal has been removed, according to the communication rate expression of step S4, the communication rate in the mixed sub-bandwidth is found to be: