EIRP control method and device for phased array antenna

Abstract

This application relates to a method and apparatus for controlling the EIRP of a phased array antenna. The control method includes: calculating the baseline EIRP of the phased array antenna in real time based on the link budget of a low-orbit satellite and the characteristics of the phased array antenna; calculating the link loss within the beam range of the phased array antenna in real time; calculating the carrier-to-noise ratio of the EIRP transmitted by the phased array antenna in real time; calculating the off-axis EIRP attenuation of the phased array antenna; and adjusting the EIRP value transmitted by the phased array antenna in real time based on the received satellite signal strength.

Description

Technical Field

[0001] The present application relates to the field of low-altitude orbit satellite Internet, and in particular to an EIRP control method and device for a phased array antenna. Background Art

[0002] Low-orbit satellite internet is a wireless communication network based on low-altitude orbit satellites, enabling local or global internet connectivity. With the rapid growth of my country's foreign trade and investment, the demand for internet is increasing. Due to their proximity to the Earth's surface, low-orbit satellites offer significantly higher signal strength, available frequencies, data bandwidth, and application scope than high-orbit satellites. A constellation of low-orbit satellites can achieve truly global coverage. Generally speaking, compared to medium- and high-orbit satellite networks, low-orbit satellite networks offer shorter latency and less path loss. Compared to terrestrial mobile communication networks, low-orbit satellite networks offer advantages such as lower costs and wider coverage.

[0003] However, low-orbit satellites have low orbits, fast speeds, and are not synchronized with the Earth. The distance between a point on the Earth and the satellite (satellite altitude) changes in real time. Changes in satellite altitude directly affect the loss of the communication link between the ground and the satellite. If ground-based phased array satellites use fixed or imprecise link estimation to transmit EIRP signals, this can lead to satellite transponder push saturation or insufficient communication rate, seriously affecting the quality of low-orbit satellite communications. Therefore, a low-orbit satellite EIRP control method is urgently needed to meet the requirements of low-orbit satellite communications. Summary of the Invention

[0004] To overcome the problems existing in the related art, the present application provides an EIRP control method and device for a phased array antenna. The control method includes: before capturing a satellite, calculating the phased array antenna's baseline EIRP value based on the low-orbit satellite link budget and the phased array antenna's characteristics; after capturing the satellite, adjusting the transmitting phased array antenna's EIRP value in real time based on changes in the strength of the signal received by the phased array antenna, so as to achieve the same EIRP value transmitted by the phased array antenna to the satellite, thereby ensuring a stable uplink rate of the phased array.

[0005] The present application provides an EIRP control method for a phased array antenna, comprising: calculating a baseline EIRP of the phased array antenna in real time based on a link budget of a low-orbit satellite and the characteristics of the phased array antenna; calculating link loss within the beam range of the phased array antenna in real time; calculating the EIRP carrier-to-noise ratio of the phased array antenna in real time; calculating the off-axis EIRP attenuation of the phased array antenna; and adjusting the EIRP value of the phased array antenna in real time based on the received satellite signal strength.

[0006] Preferably, the real-time calculation of the benchmark EIRP of the phased array antenna based on the link budget of the low-orbit satellite and the characteristics of the phased array antenna further includes: calculating the allocated bandwidth based on the service carrier information; and calculating the satellite converter carrier input back-off amount based on the satellite input power flux density of each carrier and the saturated input power spectrum density of the satellite converter.

[0007] Preferably, the real-time calculation of the link loss within the beam range of the phased array antenna further comprises:

[0008] The total uplink path loss of the phased array antenna beam is calculated based on free space loss, uplink atmospheric loss, antenna beam transmission pointing error loss and rain attenuation loss.

[0009] Preferably, the real-time calculation of the EIRP carrier-to-noise ratio transmitted by the phased array antenna further includes: calculating the EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna based on the satellite transponder quality factor, the baseline EIRP of the phased array antenna, and the total uplink path loss of the phased array antenna beam.

[0010] Preferably, the real-time calculation of the link loss within the beam range of the phased array antenna further comprises: calculating the uplink interference carrier-to-noise ratio of the phased array antenna beam according to the satellite's cross-polarization interference, neighboring satellite interference and adjacent channel interference.

[0011] Preferably, the calculating the off-axis EIRP attenuation of the phased array antenna further comprises: calculating the elevation angle EIRP attenuation of the phased array antenna according to the elevation angle of the phased array antenna.

[0012] Preferably, adjusting the EIRP value transmitted by the phased array antenna in real time based on the received satellite signal strength further includes: calculating the change in the satellite signal strength received by the phased array small station antenna based on the baseline EIRP of the phased array antenna, the total uplink path loss of the phased array antenna beam, and the EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna; and dynamically compensating the EIRP value transmitted by the phased array antenna based on the change in the satellite signal strength received by the phased array small station antenna to keep the power received by the satellite transponder to the ground station unchanged.

[0013] The present application also provides an EIRP control device for a phased array antenna, which includes: a phased array antenna, which is configured to transmit according to a steerable beam pattern; a low-orbit satellite, which is configured to communicate with a low-orbit small station antenna and a low-orbit master station antenna, respectively; a processor and a memory; the processor is used to read computer instructions in the memory and execute: real-time calculation of a baseline EIRP of the phased array antenna based on a link budget of the low-orbit satellite and characteristics of the phased array antenna; real-time calculation of link loss within the beam range of the phased array antenna; real-time calculation of the EIRP carrier-to-noise ratio transmitted by the phased array antenna; calculation of the off-axis EIRP attenuation of the phased array antenna; and real-time adjustment of the EIRP value transmitted by the phased array antenna based on the received satellite signal strength.

[0014] Preferably, the processor specifically performs: calculating the total uplink path loss of the phased array antenna beam based on free space loss, uplink atmospheric loss, antenna beam transmission pointing error loss and rain attenuation loss; calculating the EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna based on the satellite transponder quality factor, the benchmark EIRP of the phased array antenna, and the total uplink path loss of the phased array antenna beam; and calculating the elevation angle EIRP attenuation of the phased array antenna based on the elevation angle of the phased array antenna.

[0015] Preferably, the processor specifically performs the following steps: calculating a change in the satellite signal strength received by the phased array small station antenna based on a baseline EIRP of the phased array antenna, a total uplink path loss of the phased array antenna beam, and an EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna; and dynamically compensating the EIRP value transmitted by the phased array antenna based on the change in the satellite signal strength received by the phased array small station antenna to keep the power received by the satellite transponder at the ground station unchanged.

[0016] The technical solution provided by this application may include the following beneficial effects: Since the low-orbit satellite adopts the point beam coverage form, even if the phased array satellite antenna does not move, the low-orbit satellite will move, and the phased array antenna will change from the beam edge → beam center → beam edge; the receiving GT value and the transmitting EIRP value of the satellite transponder receiving and transmitting antenna at the point beam center and beam edge are different, that is, the beam center is strong and the beam edge is weak; in addition to the change in beam strength, the distance between the satellite and the phased array antenna will also change during the movement of the satellite, and then the transmission link will change; at the same time, the antenna pitch angle will also change accordingly. By keeping the on-board satellite antenna receiving and transmitting with consistent point beam coverage strength, the phased array antenna receives the change in satellite signal strength through the phased array small station antenna to dynamically compensate for the phased array antenna transmission EIRP value, so as to solve the problem that if the ground phased array satellite uses a fixed or imprecise link to estimate the EIRP transmission signal, the satellite transponder push saturation or insufficient communication rate will be caused.

[0017] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0019] Figure 1 1 is a flow chart of an EIRP control method for a phased array antenna according to an embodiment of the present application;

[0020] Figure 2 is a schematic diagram of a low-orbit satellite link budget according to an embodiment of the present application;

[0021] Figure 3 is a satellite transponder power characteristic curve diagram shown in an embodiment of the present application;

[0022] Figure 4 is a schematic diagram of air attenuation parameters shown in an embodiment of the present application;

[0023] Figure 5 1 is a schematic diagram showing EIRP attenuation caused by the elevation angle of a phased array antenna according to an embodiment of the present application;

[0024] Figure 6 This is a schematic diagram of coverage of a low-orbit satellite using a spot beam, shown in one embodiment of the present application. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0026] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0027] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0028] The technical solutions of the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0029] Figure 1 1 is a flow chart of an EIRP control method for a phased array antenna according to an embodiment of the present application. Figure 2 This is a schematic diagram of a low-orbit satellite link budget shown in an embodiment of the present application. Figure 3 This is a satellite transponder power characteristic curve diagram shown in an embodiment of the present application. Figure 4 This is a schematic diagram of air attenuation parameters shown in an embodiment of the present application. Figure 5 FIG. 1 is a schematic diagram showing EIRP attenuation caused by the elevation angle of a phased array antenna according to an embodiment of the present application. Figure 6 This is a schematic diagram of coverage of a low-orbit satellite using a spot beam, shown in one embodiment of the present application.

[0030] See also Figures 1 to 3 , a method for controlling EIRP of a phased array antenna, comprising:

[0031] S1. Calculate the benchmark EIRP of the phased array antenna in real time based on the link budget of the low-orbit satellite and the characteristics of the phased array antenna.

[0032] S2, real-time calculation of link loss within the beam range of the phased array antenna;

[0033] S3, real-time calculation of the EIRP carrier-to-noise ratio transmitted by the phased array antenna;

[0034] S4. Calculate the off-axis EIRP attenuation of the phased array antenna;

[0035] S5. Adjust the EIRP value transmitted by the phased array antenna in real time according to the received satellite signal strength.

[0036] Specifically, this control method uses a calculation based on the assumption that the power received by the satellite transponder from the ground station remains constant. Four parameters are known: ground station (master station, small station), satellite transponder parameters, service carrier parameters, and interference parameters. Based on these given parameters, the allocated bandwidth, link loss, uplink carrier-to-noise ratio, and other parameters are calculated, and adjustments are made based on the calculated results.

[0037] Please refer to Figures 1 to 3 , calculating the benchmark EIRP of the phased array antenna in real time based on the link budget of the low-orbit satellite and the characteristics of the phased array antenna further includes:

[0038] Calculate the allocated bandwidth based on the service carrier information;

[0039] The satellite converter carrier input back-off amount is calculated based on the satellite input power flux density of each carrier and the saturated input power spectrum density of the satellite converter.

[0040] Specifically, the carrier information parameters include: carrier rate / (bps) is R b , symbol rate / (sps) is Rs, carrier modulation mode is M, carrier RS outer coding is RS, carrier forward error correction code rate FEC is C r , the roll-off coefficient is α, the demodulation threshold is Eb / N0 or Es / N0, and the carrier occupies the satellite bandwidth B o / (Hz), the allocated bandwidth is B / (Hz).

[0041] Satellite parameters include: Two-line orbit number information of satellite: TLE (two-line orbit data) describes the relationship between the satellite's motion and time period. It is the satellite's ephemeris information. The structure of the satellite ephemeris is three lines. The first line of data is the satellite name. The next two lines store satellite-related data. Each line has 69 characters, including 0 to 9, A to Z, space, dot and positive and negative signs. The following is an example of TLE data:

[0042] First track number information: 49052U, 21068A, 23307.89994294, .0000525700000+0, 50467-3, 0, 9999

[0043] First track number information: 49052, 37.0188, 170.3286, 0005658, 347.734212.3260, 14.92907142123504.

[0044] First line:

[0045]

[0046] Second line:

[0047]

[0048]

[0049] Among them, the satellite saturation flux density is SFD, and the satellite quality factor is G / T sat / (dB / K), the satellite transponder input back-off is IBO / (dB), the transponder bandwidth is BW / MHz, and the uplink frequency is f u / (MHz).

[0050] The antenna parameters of the low-orbit small station include: antenna longitude is Φ1 / (°), antenna latitude is Θ1 / (°), and the isotropic radiated power of the small station is EIRP. ant / (dBW), the elevation angle of the small station antenna is β / (°).

[0051] The uplink neighboring satellite interference constant is C / ASI u , the uplink polarization interference constant is C / XPI u , the uplink intermodulation interference constant is C / IM u , the uplink adjacent channel interference constant is C / ACI u .

[0052] Based on the service carrier information, the allocated bandwidth is calculated as follows:

[0053]

[0054] Where M is the symbol base number, which is 2 for BPSK, 4 for QPSK, and 8 for 8PSK;

[0055] B o =R s ×α, B=Int(B o ).

[0056] Based on the satellite input power flux density of each carrier and the saturated input power spectrum density of the satellite converter, the satellite converter carrier input back-off amount is calculated as follows:

[0057] The saturated input power spectrum density of the converter is for a single uplink carrier. When the satellite converter input operates with multiple carriers, the satellite input power flux density of each carrier is less than the saturated input power density SPD by a backoff amount X, where the formula is as follows:

[0058]

[0059] When the transponder operates in multi-carrier mode, in addition to the reduced backoff X due to multi-carrier operation, the input rate per carrier needs to be backed off to the constant IBO provided by the satellite company, i.e.

[0060] IPBO=IBO+X

[0061] In normal circumstances, IBO=6dB.

[0062] Please refer to Figures 1 to 4 , the real-time calculation of the link loss within the beam range of the phased array antenna further includes:

[0063] The total uplink path loss of the phased array antenna beam is calculated based on free space loss, uplink atmospheric loss, antenna beam transmission pointing error loss and rain attenuation loss.

[0064] Specifically, L u is the total uplink path loss, which is equal to the free space loss L uF , Upward atmospheric loss L au , transmission pointing error loss L ou and rain attenuation loss L rianu The sum of several losses, namely:

[0065] L u =L uF +L au +L ou +L rianu

[0066] The first step is to calculate the free space loss as:

[0067] L uF =32.44+20logd+20logf

[0068] Where d represents the distance from the ground antenna to the satellite (unit: km), and f represents the communication frequency (unit: MHz).

[0069] The distance d between the satellite and the ground station is calculated as follows:

[0070] Assume that the average angular velocity of motion is: n = 360*V, V is the number of orbits the satellite orbits the earth per day, the semi-major axis of the orbit is a = (μ / n2)1 / 3, the gravitational constant μ is 398600.5, ω0 is the argument of perigee, Ω0 is the right ascension of the ascending node, i is the orbital intersection angle, e is the orbital eccentricity, K1 is a constant of 66063.1704 km, the Julian day of the base year is JD, where time t0 = JD+T, t is the current universal time UT, and K = nK1 / a 2 (1-e 2 ) 2 .

[0071] Among them, the rate of change of the right ascension of the ascending node is dΩ / dt=-Kcosi

[0072] Among them, the rate of change of the perigee argument is dω / dt=K(2-2.5sin 2 i)

[0073] Among them, the rate of change of the angle of the mean perihelion is dV / dt=2π*V

[0074] Among them, the right ascension of the ascending node is Ω=Ω0+dΩ / dt(t-t0)

[0075] Wherein, the argument of perigee is ω=ω0+dω / dt(t-t0)

[0076] Wherein, the mean anomaly angle is E=E0+dV / dt(t-t0)

[0077] The satellite coordinates are: r = a(1-ecosE), x0 = rcosv, y0 = rsinv.

[0078] The satellite's geocentric equatorial plane vernal equinox coordinates:

[0079] x i =(cosΩcosω-sinΩsinωcosi)x0+(-cosΩsinω-sinΩcosωcosi)y0

[0080] y i =(sinΩcosω+cosΩsinωcosi)x0+(-sinΩsinω+cosΩcosωcosi)y0

[0081] z i =(sinωsini)x0+(cosωsini)y0

[0082] The satellite's geocentric equatorial coordinates in Greenwich:

[0083] x g =cos(GST)x i +sin(GST)y i ;

[0084] y g =-sin(GST)x i +cos(GST)y i ;

[0085] z g =zi;

[0086] In GST, which stands for Greenwich Mean Time, (T u =(JD-2451545) / 36525,GST=67310.54841+(876600+8640184.812866)*T u +0.093104T 2 u -6.2*106Tu3).

[0087] The terminal geocentric latitude is:

[0088] φgc=arctan((R p / R e )tan(φg))

[0089] Distance from terminal to geocenter:

[0090]

[0091] Among them, R e is the Earth's equatorial radius of 6378.137 km, R is the Earth's polar radius of 6356.755 km, h is the satellite terminal's altitude in km, φg is the terminal's geographical latitude, and λ is the Earth's polar radius of 6356.755 km. g is the longitude of the terminal geographic system;

[0092] Finally, the Earth-centered equatorial plane Greenwich coordinates of the satellite terminal are:

[0093] x t =rtcosφgccosλ g ,y t =rtcosφgcsinλ g , z t =rtsinφgc.

[0094] The horizontal coordinates of the satellite's site are:

[0095] x h =sinφgccosλ g (x g -x t )+sinφgcsinλ g (y g -y t )-cosφgc(z g -z t );

[0096] y h = -sinλ g (x g -x t )+cosλ g (y g -y t );

[0097] z h =cosφgccosλ g (x g -x t )+cosφgcsinλ g (y g -y t )+sinφgc(z g -z t );

[0098] Finally, the distance from the terminal to the satellite:

[0099]

[0100] The elevation angle from the terminal to the satellite is:

[0101]

[0102] See Figure 4 ,The second step is to calculate the atmospheric loss as follows:

[0103] In clear weather, the atmosphere (mainly O2 and H2O molecules) will cause additional absorption losses to radio wave propagation.

[0104] Referring to the ITU-R_P.676-13 standard model, the calculation formula is as follows:

[0105] A=γr0, where γ is the air absorption rate (Km / dB) and r0 is the electromagnetic wave propagation path (Km).

[0106] The third step is to calculate rain attenuation, rain fog attenuation and snow attenuation as follows:

[0107] Among them, rain attenuation L rain for:

[0108] According to Recommendation ITU-R P.838-3, the relationship between rain attenuation (dB / Km) and rainfall intensity (R) (mm / h) is: R =fR a , where f and is the communication signal frequency (GHz) and the angle between the electromagnetic wave and the rainfall (θ). Generally, the height h during rainfall is no more than 5 km, so the rain attenuation L rain for:

[0109] L rain =γ R ·h / sinθ

[0110] The cloud attenuation is:

[0111]

[0112] In the above formula, f is the frequency (GHz), V m is visibility m, dense fog is V m <50m, dense fog: 50m≤V m <200m, moderate fog is 200m≤Vm<500m.

[0113] Among them, the snow attenuation is:

[0114] L s =7.47×10 -5 f·I·(1+5.77×10 -5 f 3 I 0.6)(dB / km)

[0115] In the above formula, f is the frequency (GHz), and I is the snowfall intensity in mm / h.

[0116] In one embodiment, it also includes tracking error loss. The tracking error is required to be less than one-eighth of the beam width. The tracking loss needs to be determined based on the radiation pattern. Usually, the alignment deviation loss is less than 0.5dB.

[0117] In one embodiment, the real-time calculation of the EIRP carrier-to-noise ratio transmitted by the phased array antenna further includes:

[0118] Calculate the EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna based on the satellite transponder quality factor, the benchmark EIRP of the phased array antenna, and the total uplink path loss of the phased array antenna beam.

[0119] Specifically,

[0120] Satellite transponder quality factor [G / T] sat , the isotropic radiated power of the phased array antenna is EIRP ant , the uplink carrier-to-noise ratio is:

[0121] [C / T] u =[EIRP] ant -L u +[G / T] sat

[0122] N=K*B sat *T SR

[0123] [C / N] = [C / T] u -KB n

[0124] Where K = -228.6dB Boltz constant, Bn allocation bandwidth / noise bandwidth, T SR The satellite system noise coefficient plus various uplink interferences can be obtained to obtain the total uplink carrier-to-noise ratio [C / (N+I)]:

[0125]

[0126] When the satellite is a multi-carrier, the satellite transponder carrier fallback is considered, and the fallback method is based on the above multi-carrier method.

[0127] In one embodiment, the real-time calculation of the link loss within the beam range of the phased array antenna further includes: calculating the uplink interference carrier-to-noise ratio of the phased array antenna beam based on the satellite's cross-polarization interference, neighboring satellite interference, and adjacent channel interference.

[0128] Specifically, satellite communications may have some interference. The total carrier-to-noise ratio processing of the satellite link takes into account the uplink and downlink carrier-to-noise ratio, as well as various interferences. Common interferences include cross-polarization interference, neighboring satellite interference, and adjacent channel interference. Among them, adjacent channel uplink interference ACI u , when the inter-carrier spacing is sufficient, this interference can be ignored, according to [C / ACI] u >35dB, [C / ACI] d >35dB. Downlink [C / ASI] u Sporadic interference: If two satellites have similar sight angles and the same frequency, the satellite may receive uplink interference from the neighboring satellite’s ground transmitter. If there is no neighboring satellite with the same frequency, this interference can be ignored and [C / ASI] can be pressed. u Cross-polarization interference: The repeater uses polarization isolation for frequency reuse. The polarization isolation between the ground antenna and the ground is not ideal. Raindrops can also introduce polarization changes during transmission, causing cross-polarization interference. u >27dB is considered for calculation. Intermodulation interference, if the uplink station power amplifier works in the linear region, this interference can be ignored, press [C / IM] es >40dB. Finally, the uplink interference carrier-to-noise ratio is:

[0129]

[0130] Please refer to Figure 1 as well as Figure 5 , the calculating the off-axis EIRP attenuation of the phased array antenna further includes:

[0131] Calculate the elevation EIRP attenuation of the phased array antenna based on the elevation angle of the phased array antenna.

[0132] Specifically, the phased antenna pitch EIRP attenuation is:

[0133] EIRP ant =EIRP p1dB +10log 10 (cos 1.5 (θ)

[0134] Wherein, θ = 90-β, β is the antenna elevation angle.

[0135] Therefore, it is necessary to compensate for the EIRP attenuation of the phased array antenna elevation angle according to the elevation angle of the phased array antenna.

[0136] In one embodiment, adjusting the EIRP value transmitted by the phased array antenna in real time according to the received satellite signal strength further includes:

[0137] Calculate the change in satellite signal strength received by the phased array small station antenna based on the phased array antenna's baseline EIRP, the total uplink path loss of the phased array antenna beam, and the EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna.

[0138] According to the change in the satellite signal strength received by the phased array base station antenna, the EIRP value of the phased array antenna transmission is dynamically compensated to keep the power received by the satellite transponder at the ground station unchanged.

[0139] Please refer to Figure 1 as well as Figure 6 Dynamic compensation adjusts the EIRP of the phased array antenna's transmission. For low-orbit satellites using point beam coverage, even if the phased array satellite antenna does not move, the low-orbit satellite will move, and the phased array antenna will change from beam edge to beam center to beam edge. The satellite transponder's receiving and transmitting antennas have different receiving GT values and transmitting EIRP values at the point beam center and beam edge, with the beam center being strong and the beam edge being weak. In addition to changes in beam strength, the satellite's movement also causes changes in the distance between the satellite and the phased array antenna, which in turn changes the transmission link. The antenna's elevation angle will also change accordingly. Beam attenuation is compensated for using a relative method. The principle of satellite beam change calculation is: the onboard satellite antenna receives and transmits point beam coverage with consistent intensity. The phased array antenna receives changes in satellite signal strength to dynamically compensate for the phased array antenna's transmission EIRP. The base station transmit EIRP value is calculated using the link budget and the phased antenna EIRP value. The phased antenna transmit EIRP compensation value is dynamically adjusted based on changes in the received signal. When the received signal increases, the phased antenna EIRP is reduced; when the received signal decreases, the phased antenna EIRP is increased.

[0140] Before capturing a satellite, the phased array antenna calculates the ERP baseline value of the phased array antenna in real time based on the satellite orbit and local longitude and latitude, satellite antenna parameters, phased array antenna parameters, weather environment, and transponder beam conditions. Then, after the phased array antenna captures the satellite, the phased array antenna's transmit EIRP value is adjusted based on the received signal strength of the phased array antenna. The EIRP value of the phased array antenna is reduced by the same amount as the received signal value increases.

[0141] The technical solution provided by this application may include the following beneficial effects: before capturing a satellite, a baseline EIRP value of the phased array antenna is calculated based on the low-orbit satellite link budget and the phased array antenna characteristics. After capturing the satellite, the EIRP value of the transmitting phased array antenna is adjusted in real time based on the change in the strength of the signal received by the phased array antenna. This ensures that the EIRP values transmitted by the phased array antenna to the satellite are the same, ensuring the stability of the phased array uplink rate. The solution can be widely used in the field of low-orbit satellite communications using phased array antennas, making it possible to control the transmitting EIRP of the low-orbit phased array antenna.

[0142] The present application also provides an EIRP control device for a phased array antenna, which includes: a phased array antenna, which is configured to transmit according to a steerable beam pattern; a low-orbit satellite, which is configured to communicate with a low-orbit small station antenna and a low-orbit master station antenna, respectively; a processor and a memory; the processor is used to read computer instructions in the memory and execute: real-time calculation of a baseline EIRP of the phased array antenna based on a link budget of the low-orbit satellite and characteristics of the phased array antenna; real-time calculation of link loss within the beam range of the phased array antenna; real-time calculation of the EIRP carrier-to-noise ratio transmitted by the phased array antenna; calculation of the off-axis EIRP attenuation of the phased array antenna; and real-time adjustment of the EIRP value transmitted by the phased array antenna based on the received satellite signal strength.

[0143] In one embodiment, the processor specifically performs the following operations: calculating the total uplink path loss of the phased array antenna beam based on free space loss, uplink atmospheric loss, antenna beam transmission pointing error loss, and rain attenuation loss; calculating the EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna based on the satellite transponder quality factor, the baseline EIRP of the phased array antenna, and the total uplink path loss of the phased array antenna beam; and calculating the elevation EIRP attenuation of the phased array antenna based on the elevation angle of the phased array antenna.

[0144] In one embodiment, the processor specifically performs the following steps: calculating a change in the satellite signal strength received by the phased array small station antenna based on a baseline EIRP of the phased array antenna, a total uplink path loss of the phased array antenna beam, and an EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna; and dynamically compensating the EIRP value transmitted by the phased array antenna based on the change in the satellite signal strength received by the phased array small station antenna to keep the power received by the satellite transponder at the ground station unchanged.

[0145] The embodiments of the present application have been described above. The above description is illustrative and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for controlling EIRP of a phased array antenna, characterized in that: include: Based on the link budget of the low-orbit satellite and the characteristics of the phased array antenna, the benchmark EIRP of the phased array antenna is calculated in real time; Real-time calculation of link loss within the beam range of phased array antennas; Real-time calculation of the EIRP carrier-to-noise ratio transmitted by the phased array antenna; Calculate the off-axis EIRP attenuation of phased array antennas; Adjust the EIRP value transmitted by the phased array antenna in real time according to the received satellite signal strength; Calculating the off-axis EIRP attenuation of the phased array antenna further includes: Calculate the elevation angle EIRP attenuation of the phased array antenna according to the elevation angle of the phased array antenna; The EIRP attenuation of the phased antenna is: Where θ = 90 - β, β is the antenna elevation angle; The step of adjusting the EIRP value transmitted by the phased array antenna in real time according to the received satellite signal strength further includes: Calculate the change in satellite signal strength received by the phased array small station antenna based on the phased array antenna's baseline EIRP, the total uplink path loss of the phased array antenna beam, and the EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna. Dynamically compensate the EIRP value of the phased array antenna based on the change in the satellite signal strength received by the phased array base station antenna to keep the power received by the satellite transponder at the ground station unchanged; Calculating the benchmark EIRP of the phased array antenna in real time based on the link budget of the low-orbit satellite and the characteristics of the phased array antenna further includes: Calculate the allocated bandwidth based on the service carrier information; Calculate the satellite converter carrier input backoff amount according to the satellite input power flux density of each carrier and the saturated input power spectrum density of the satellite converter; Based on the satellite input power flux density of each carrier and the saturated input power spectrum density of the satellite converter, the satellite converter carrier input back-off amount is calculated as follows: The saturated input power spectrum density of the satellite converter is for a single uplink carrier. When the satellite converter input operates with multiple carriers, the satellite input power flux density of each carrier is less than the saturated input power density SPD by a backoff amount X, where the formula is as follows: When the satellite converter works on multiple carriers, in addition to the reduced backoff X due to the multi-carrier reason, it is also necessary to backoff the input rate of each carrier to the constant IBO provided by the satellite company, that is, Among them, under normal circumstances IBO=6dB.

2. The EIRP control method of a phased array antenna according to claim 1, wherein: The real-time calculation of the link loss within the beam range of the phased array antenna further includes: The total uplink path loss of the phased array antenna beam is calculated based on free space loss, uplink atmospheric loss, antenna beam transmission pointing error loss and rain attenuation loss.

3. The EIRP control method of a phased array antenna according to claim 2, wherein: The real-time calculation of the EIRP carrier-to-noise ratio transmitted by the phased array antenna further includes: Calculate the EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna based on the satellite transponder quality factor, the benchmark EIRP of the phased array antenna, and the total uplink path loss of the phased array antenna beam.

4. The EIRP control method of a phased array antenna according to claim 2, wherein: The real-time calculation of the link loss within the beam range of the phased array antenna further includes: calculating the uplink interference carrier-to-noise ratio of the phased array antenna beam according to the cross-polarization interference, neighboring satellite interference and adjacent channel interference of the satellite.

5. An EIRP control device for a phased array antenna, characterized in that: include: a phased array antenna configured to transmit according to a steerable beam pattern; a low-orbit satellite configured to communicate with a low-orbit small station antenna and a low-orbit main station antenna respectively; processor and memory; The processor is configured to read computer instructions in the memory and execute: Based on the link budget of the low-orbit satellite and the characteristics of the phased array antenna, the benchmark EIRP of the phased array antenna is calculated in real time; Real-time calculation of link loss within the beam range of phased array antennas; Real-time calculation of the EIRP carrier-to-noise ratio transmitted by the phased array antenna; Calculate the off-axis EIRP attenuation of phased array antennas; Adjust the EIRP value transmitted by the phased array antenna in real time according to the received satellite signal strength; Calculate the elevation angle EIRP attenuation of the phased array antenna according to the elevation angle of the phased array antenna; The EIRP attenuation of the phased antenna is: Where θ = 90 - β, β is the antenna elevation angle; The processor specifically performs: Calculate the change in satellite signal strength received by the phased array small station antenna based on the phased array antenna's baseline EIRP, the total uplink path loss of the phased array antenna beam, and the EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna. Dynamically compensate the EIRP value of the phased array antenna based on the change in the satellite signal strength received by the phased array base station antenna to keep the power received by the satellite transponder at the ground station unchanged; Calculating the baseline EIRP of the phased array antenna in real time further includes: Calculate the allocated bandwidth based on the service carrier information; Calculate the satellite converter carrier input backoff amount according to the satellite input power flux density of each carrier and the saturated input power spectrum density of the satellite converter; Based on the satellite input power flux density of each carrier and the saturated input power spectrum density of the satellite converter, the satellite converter carrier input back-off amount is calculated as follows: The saturated input power spectrum density of the satellite converter is for a single uplink carrier. When the satellite converter input operates with multiple carriers, the satellite input power flux density of each carrier is less than the saturated input power density SPD by a backoff amount X, where the formula is as follows: When the satellite converter works on multiple carriers, in addition to the reduced backoff X due to the multi-carrier reason, it is also necessary to backoff the input rate of each carrier to the constant IBO provided by the satellite company, that is, Among them, under normal circumstances IBO=6dB.

6. The EIRP control device for a phased array antenna according to claim 5, wherein: The processor specifically performs: Calculate the total uplink path loss of the phased array antenna beam based on free space loss, uplink atmospheric loss, antenna beam pointing error loss, and rain attenuation loss; Calculate the EIRP uplink carrier-to-noise ratio transmitted by the phased array antenna based on the satellite transponder quality factor, the benchmark EIRP of the phased array antenna, and the total uplink path loss of the phased array antenna beam.

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