Satellite communication system uplink power control method and control device

Abstract

This invention relates to an uplink power control method and control device for a satellite communication system. The uplink power control method for the satellite communication system includes: S100, acquiring the downlink signal strength P0 of the satellite under clear sky weather conditions; S200, at t i Continuously measure the signal strength P of the satellite downlink under severe weather conditions i S300, based on P0 and P i Calculate the downlink signal attenuation value Ad i S400 divides the uplink frequency band into multiple sub-bands, according to Ad... i Calculate the signal attenuation value Au for each uplink sub-band. ki S500, according to Au ki Adjust the compensation attenuation value A of the corresponding sub-band ki This can effectively reduce uplink power compensation errors in satellite communication systems and improve the control accuracy of uplink power.

Description

Technical Field

[0001] This invention relates to the field of satellite communication technology, and specifically to an uplink power control method and control device for a satellite communication system. Background Technology

[0002] Broadband satellite communication systems generally refer to high-speed satellite communication systems that carry broadband internet access services and new broadband multimedia services. Inclement weather such as rain and snow significantly impacts signal transmission in satellite communication systems. Current methods for controlling uplink power to combat rain attenuation in broadband satellite communication systems are as follows: Figure 1 As shown, the uplink signal is compensated for by the processor to reduce rain attenuation. However, compared to traditional satellite communication, broadband satellite communication has a wider bandwidth, higher data rate, and greater capacity. Broadband satellite communication currently mostly uses the Ka band, but may develop towards higher frequency bands such as Q / V and W in the future. Traditional satellite communication systems, such as Ku-band, typically have a bandwidth of only 500MHz, while Ka-band broadband satellite communication systems can reach bandwidths of over 2.5GHz. Therefore, using a uniform compensation power value across the entire uplink frequency band using current methods is acceptable for traditional satellite communication systems with narrow bandwidths. However, for broadband satellite communication systems, using a uniform compensation power value across the entire frequency band will result in large uplink power compensation errors. Summary of the Invention

[0003] In view of this, the present invention aims to propose an uplink power control method and control device for satellite communication systems, so as to solve the problem of large uplink power control error in current satellite communication systems.

[0004] In a first aspect, embodiments of the present invention provide an uplink power control method for a satellite communication system, the uplink power control method for the satellite communication system comprising:

[0005] S100, obtain the signal strength P0 of the satellite downlink under clear weather conditions;

[0006] S200, in t i Continuously measure the signal strength P of the satellite downlink under severe weather conditions i ;

[0007] S300, based on P0 and P i Calculate the downlink signal attenuation value Ad i ;

[0008] S400 divides the uplink frequency band into multiple sub-bands, according to Ad... i Calculate the signal attenuation value Au for each uplink sub-band. ki ;

[0009] S500, according to Auki Adjust the compensation attenuation value A of the corresponding sub-band ki .

[0010] Preferably, in step S200, the severe weather includes rain, snow, fog, and hail.

[0011] Preferably, in step S300, the signal attenuation value Ad i The calculation formula is:

[0012] Ad i =P0-P i .

[0013] Preferably, in step S400, the uplink sub-band attenuation value Au ki Calculated using the following formula:

[0014]

[0015]

[0016] in, and Calculated using the following formula:

[0017]

[0018]

[0019] Where f1 is the downlink signal attenuation value A di The corresponding frequency, f2 is the uplink sub-band attenuation value Au. ki The corresponding frequency.

[0020] Preferably, in step S500, the compensation attenuation value A ki Calculated using the following formula:

[0021] A ki =A ki-1 +Au ki-1 -Au ki

[0022] A ki-1 For t i-1 The compensation attenuation value of the corresponding uplink sub-band at any given time, Au ki-1 For t i-1 The signal attenuation value of the corresponding uplink sub-band at any time.

[0023] Preferably, after step S500, the method further includes:

[0024] S600, the link signals of multiple uplink sub-bands are combined to form a complete uplink signal.

[0025] Preferably, there is frequency overlap between two adjacent uplink sub-bands.

[0026] Preferably, the number of uplink sub-bands is two, three, or four.

[0027] In a second aspect, embodiments of the present invention also provide an uplink power control device for a satellite communication system, used in accordance with the uplink power control method for a satellite communication system according to any one of the first aspects, wherein the uplink power control device for the satellite communication system comprises:

[0028] A receiver for receiving clear-sky signals, receiving satellite downlink signals, and measuring the signal strength of the downlink signals at a predetermined frequency;

[0029] The processor is used to receive signal strength information from the receiver, compare downlink signal strength under clear sky and downlink signal strength under severe weather, and calculate uplink signal attenuation value.

[0030] Multiple uplink power control units, each corresponding one-to-one with one of the multiple uplink sub-bands, are used to receive uplink signal attenuation information from the processor and to compensate for uplink attenuation; and

[0031] A combiner is used to combine link signals from multiple uplink sub-bands.

[0032] This invention divides the uplink signal of a satellite communication system into multiple sub-bands. Based on the attenuation value of the downlink signal, the signal attenuation of each uplink sub-band is compensated separately. Since the bandwidth of the sub-band is narrower, the compensation and control error is smaller. Compared with compensating for signal attenuation of the entire uplink frequency band, the compensation error can be effectively reduced, thereby effectively improving the uplink power control accuracy of the satellite communication system. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the uplink power control system of a current satellite communication system.

[0035] Figure 2 This is a schematic diagram of the uplink power control device of a satellite communication system according to an embodiment of the present invention;

[0036] Figure 3 and Figure 4This is a schematic diagram of an uplink power control method for a satellite communication system according to an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the frequency overlap between adjacent uplink sub-bands in an embodiment of the present invention. Detailed Implementation

[0038] The description of the embodiments in this specification should be taken in conjunction with the accompanying drawings, which should form part of the complete specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and may be indicated in a simplified or convenient manner. Furthermore, parts of the various structures in the drawings will be described separately; it is worth noting that elements not shown in the figures or not described in words are in a form known to those skilled in the art.

[0039] The descriptions of the embodiments herein, including any references to directions and orientations, are for ease of description only and should not be construed as limiting the scope of the invention. The following description of preferred embodiments involves combinations of features, which may exist independently or in combination; the invention is not particularly limited to the preferred embodiments. The scope of the invention is defined by the claims.

[0040] like Figure 2 The diagram shows a schematic of the uplink power control device of a satellite communication system according to an embodiment of the present invention. The uplink power control device includes a receiver, a processor, multiple uplink power control units, and a combiner. The receiver receives downlink signals under clear skies and in real-time, and measures the signal strength of downlink signals at predetermined frequencies. The processor divides the uplink signal frequency band into multiple sub-bands, receives signal strength information from the receiver, compares the downlink signal strength under adverse weather conditions with that under clear skies, converts the signal strength difference according to frequency to estimate the rainfall attenuation value of the uplink in different frequency bands, and sends this information to the uplink power control units. Each uplink power control unit corresponds one-to-one with an uplink sub-band. The uplink power control unit adjusts the uplink power according to the uplink attenuation value sent by the processor to compensate for uplink attenuation. The combiner synthesizes the uplink signals from multiple frequency bands to form a complete broadband uplink signal.

[0041] like Figure 3 and Figure 4 The diagram shown is a flowchart illustrating the uplink power control method for a satellite communication system according to an embodiment of the present invention. This method can be implemented based on the aforementioned control device. The uplink power control method for the satellite communication system includes:

[0042] S100, obtain the signal strength P0 of the satellite downlink under clear weather conditions;

[0043] In this embodiment, at the initial time t0 (clear weather), the downlink signal strength measured by the receiver is calibrated as the clear-sky downlink signal strength P0. Theoretically, the clear-sky downlink signal strength P0 is the maximum value of the downlink signal strength.

[0044] S200, in t i Continuously measure the signal strength P of the satellite downlink under severe weather conditions i ;

[0045] In this embodiment, severe weather includes, but is not limited to, rain, snow, fog, hail, etc., which can interfere with the electromagnetic waves that transmit signals.

[0046] S300, based on P0 and P i Calculate the downlink signal attenuation value Ad i ;

[0047] In this embodiment, the signal attenuation value Ad i The calculation formula is: Ad i =P0-P i .

[0048] S400 divides the uplink frequency band into multiple sub-bands, according to Ad... i Calculate the signal attenuation value Au for each uplink sub-band. ki ;

[0049] In this embodiment, the uplink sub-band attenuation value Au ki Calculated using the following formula:

[0050]

[0051]

[0052] in, and Calculated using the following formula:

[0053]

[0054]

[0055] Where f1 is the downlink signal attenuation value A di The corresponding frequency, f2 is the uplink sub-band attenuation value Au. ki The corresponding frequency.

[0056] S500, according to Au ki Adjust the compensation attenuation value for the corresponding sub-frequency band;

[0057] In this embodiment, an adjustable attenuator is used to compensate for the attenuation value A. kiCompensation will be provided, including:

[0058] A ki =A ki-1 +Au ki-1 -Au ki

[0059] A ki-1 For t i-1 The compensation attenuation value of the corresponding uplink sub-band at any given time, Au ki-1 For t i-1 The signal attenuation value of the corresponding uplink sub-band at any time.

[0060] S600, the link signals of multiple uplink sub-bands are combined to form a complete uplink signal.

[0061] In step S400, the number of sub-bands into which the uplink frequency band is divided is unlimited. More sub-bands result in more accurate uplink power compensation and smaller errors, but this also reduces the bandwidth of each sub-band, affecting the bandwidth of the transmitted signal. Furthermore, each sub-band requires an uplink power control unit, increasing system construction costs. Considering uplink power compensation accuracy, transmission signal bandwidth, and system construction costs, 2 to 4 sub-bands are preferable in practical broadband satellite communication systems. Additionally, Formula 1 in step S400 has high accuracy in the signal frequency range of 7GHz-55GHz; therefore, it is preferable to divide the sub-bands so that the frequency range of each sub-band is within 7GHz-55GHz.

[0062] like Figure 5 As shown in this embodiment, there is frequency overlap between each adjacent uplink sub-band. In other words, the maximum frequency of the preceding sub-band is greater than the minimum frequency of the following sub-band, thereby ensuring that the uplink signal at the frequency overlap point can be output normally and guaranteeing signal integrity. The degree of frequency overlap depends on the bandwidth of the uplink signal at the frequency overlap point, which is not limited in this embodiment.

[0063] The uplink power control method and control device for satellite communication systems of the present invention divide the uplink signal of the satellite communication system into multiple sub-bands. Based on the attenuation value of the downlink signal, the signal attenuation of each uplink sub-band is compensated separately. The bandwidth of the sub-band is narrower, and the compensation and control error is smaller. Compared with compensating for signal attenuation of the entire uplink frequency band, the compensation error can be effectively reduced, thereby effectively improving the uplink power control accuracy of the satellite communication system.

[0064] The uplink power control method and control device of the satellite communication system according to the present invention will be described in detail below under two conditions: Ka-band 3 and Ka-band 4, under rainfall conditions.

[0065] Ka band under rainfall conditions

[0066] The Ka-band uplink frequency range is 27.5–30.0 GHz, and the downlink frequency range is 17.7–20.2 GHz. The frequency ranges of the three uplink sub-bands are as follows:

[0067] Frequency Band 1: 27.5–28.4 GHz

[0068] Frequency band 2: 28.3–29.2 GHz

[0069] Frequency Band 3: 29.1–30.0 GHz

[0070] Assume the downlink signal frequency received and measured by the receiver is 17.7 GHz, and the downlink signal strength is 10 dB lower during rainfall compared to clear skies. Let f be the starting frequency of each frequency band. a The termination frequency is denoted as f. b The center frequency is denoted as f. av =(f a +f b ) / 2. Based on the formula in step S400, frequency conversion is performed on the starting frequency, ending frequency, and center frequency of each uplink frequency band to convert the downlink rainfall attenuation into the uplink rainfall attenuation value. The resulting rainfall attenuation values ​​are denoted as A. a A b A av Take A av -A a and A b -A av The maximum value is the rain attenuation compensation error. The results are listed in Table 1 below. It can be concluded that under the aforementioned premise, the maximum rain attenuation compensation error of the Ka full-band uplink power control using the unified compensation power method is 1.383dB, while the maximum rain attenuation compensation error using the three-band segmented compensation method is 0.501dB. The rain attenuation compensation error of the three-band segmented compensation method is 36.2% of the rain attenuation compensation error of the full-band unified compensation method.

[0071]

[0072] Table 1

[0073] Ka band under rainfall conditions

[0074] The Ka-band uplink frequency range is 27.5–30.0 GHz, and the downlink frequency range is 17.7–20.2 GHz. The frequency ranges for the four bands are as follows:

[0075] Frequency band 1: 27.5–28.2 GHz

[0076] Frequency Band 2: 28.1–28.8 GHz

[0077] Frequency band 3: 28.7–29.4 GHz

[0078] Frequency band 4: 29.3–30.0 GHz

[0079] The remaining conditions are the same as in the Ka three-band implementation. The results are shown in Table 2 below. It can be concluded that the maximum rain attenuation compensation error using the unified compensation power method for uplink power control in the Ka full band is 1.383dB, while the maximum rain attenuation compensation error using the four-band segmented compensation method is 0.390dB. The rain attenuation compensation error using the four-band segmented compensation method is 28.2% of the rain attenuation compensation error of the unified compensation method in the full band.

[0080]

[0081] Table 2

[0082] The analysis of the results of the Ka three-band and Ka four-band shows that the control method of the present invention can effectively reduce the rain attenuation compensation error, greatly improve the accuracy of rain attenuation compensation, and the more frequency bands are divided in the uplink frequency band, the more accurate the uplink power compensation and the smaller the error.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An uplink power control method for a satellite communication system, characterized in that, The uplink power control method of the satellite communication system includes: S100, obtain the signal strength of the satellite downlink under clear weather conditions. ; S200, in Continuously measure the signal strength of the satellite downlink under adverse weather conditions ; S300, according to and Calculate the downlink signal attenuation value Signal attenuation value The calculation formula is: = - ； S400 divides the uplink frequency band into multiple sub-bands, according to Calculate the signal attenuation value for each uplink sub-band. Uplink subband attenuation value Calculated using the following formula: in, and Calculated using the following formula: = = in, Downlink signal attenuation value The corresponding frequency, Uplink sub-band attenuation value The corresponding frequency; There is frequency overlap between two adjacent uplink sub-bands; S500, according to Adjust the compensation attenuation value of the corresponding sub-band The compensation attenuation value Calculated using the following formula: for The compensation attenuation value for the corresponding uplink sub-band at any given time. for The signal attenuation value of the corresponding uplink sub-band at any time; The S600 synthesizes the link signals from multiple uplink sub-bands to form a complete uplink signal.

2. The uplink power control method for a satellite communication system according to claim 1, characterized in that, In step S200, the severe weather includes rain, snow, fog, and hail.

3. The uplink power control method for a satellite communication system according to claim 1 or 2, characterized in that, The number of uplink sub-bands is two, three, or four.

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