A method for reducing terminal power consumption during low earth orbit satellite overpass

Abstract

The application discloses a method for reducing terminal power consumption in the process of low-orbit satellite overtrack, comprising the following steps: a terminal acquires its geographical position coordinates and system time through a GNSS module, reads a pre-stored satellite ephemeris file, and calculates spatial coordinates, azimuth, elevation angle and spatial distance of a target low-orbit satellite; link path loss is estimated in combination with a free space path loss model and an atmospheric attenuation model, and an elevation angle-equivalent isotropically radiated power optimization mapping table is generated according to antenna directional diagram characteristics and power amplifier efficiency characteristics; the target equivalent isotropically radiated power is determined according to the current elevation angle, power dynamic adjustment is realized by adjusting the power supply voltage of a transceiving integrated chip for a phased array terminal, and radio frequency link gain is adjusted through a numerical control adjustable attenuator for a non-phased array terminal; the signal-to-noise ratio or the bit error rate of a received signal is monitored, and the transmission power is increased when the preset threshold is not met. The application can reduce power consumption while ensuring communication reliability and prolong the endurance time.

Description

Technical Field

[0001] This invention relates to the field of satellite communication technology, and in particular to a method for reducing terminal power consumption during the orbital transit of low-Earth orbit satellites. Background Technology

[0002] With the rapid deployment of domestic low-Earth orbit (LEO) satellite internet constellations such as GW and Qianfan, the power consumption of satellite communication ground terminals has become a key bottleneck affecting user experience and device battery life. Because LEO satellites are at relatively low altitudes and move at high speeds relative to the ground, the path loss of the communication link continuously changes throughout the entire process of satellite orbit change, from rise to fall.

[0003] In existing technologies, terminals typically employ fixed transmit power or closed-loop power control mechanisms. However, fixed power strategies, while ensuring communication quality at low elevation angles, often result in energy waste during high elevation angles; while traditional closed-loop power control relies on satellite feedback, incurring time delays and making it difficult to predict link loss trends. For battery-powered portable handheld terminals or mobile IoT devices, this suboptimal power allocation shortens the terminal's operating time. Therefore, it is necessary to predict link loss changes based on satellite orbital position and adjust the terminal's transmit power accordingly.

[0004] Chinese invention patent CN112996093B discloses a method and system for radio frequency power control of a low-orbit satellite ground terminal. It adopts a dual power control method based on satellite ephemeris and downlink closed-loop control. It utilizes time and position parameters provided by GNSS satellites, calculates satellite transit conditions and the distance between the terminal and the satellite by pre-stored ephemeris, determines the current optimal uplink power value based on the link parameters corresponding to the satellite communication frequency and the distance between the terminal and the satellite, and uses this uplink power value to initiate network connection. After the network connection is completed, the ground terminal performs power control fine-tuning by receiving control word information in the satellite downlink service PCCH channel. However, CN112996093B primarily determines the uplink power based on satellite communication link parameters and the distance between the terminal and the satellite, without considering the nonlinear efficiency characteristics of the terminal power amplifier under different output powers, nor does it disclose the equivalent omnidirectional radiated power optimization method for the entire over-orbit process aimed at reducing the total power consumption of the terminal; its closed-loop power control after network access relies on the control words sent by the satellite through the PCCH channel, without providing specific methods for the terminal to make threshold judgments and step-by-step power back-off based on the locally detected signal-to-noise ratio or bit error rate; in addition, it does not distinguish between the different hardware structures and power execution methods of phased array terminals and non-phased array terminals.

[0005] Chinese invention patent CN114845404B discloses a method for controlling the uplink power of users in asymmetric channels of narrowband GEO satellite communication. This method calculates the off-axis angle of the user's position relative to the beam center in the satellite coordinate system, and estimates the user's downlink signal reception power under ideal conditions by combining the satellite beam gain pattern. By comparing the user's actual downlink signal reception power with the user's downlink signal reception power under ideal conditions, the non-ideal attenuation value of the downlink channel is obtained. The user terminal uses the non-ideal attenuation value of the downlink channel and a frequency compensation factor to perform open-loop pre-compensation on the uplink transmit power, and the control section performs non-real-time closed-loop control of the user's transmit power according to actual needs. However, CN114845404B is designed for GEO satellite communication scenarios. GEO satellites are basically stationary relative to the ground. Its power control mainly addresses the power differences of users at different locations within the beam, non-ideal channel attenuation, and co-channel multiple access interference. It does not address the terminal power consumption optimization under the condition of continuous changes in elevation angle and satellite-to-ground distance during the low-orbit satellite's overpass. Its open-loop pre-compensation is mainly determined based on the non-ideal attenuation value of the downlink channel and the frequency compensation factor. It does not combine the efficiency characteristics of the terminal power amplifier to generate an equivalent omnidirectional radiated power optimization mapping relationship for the entire overpass process. Its closed-loop control is initiated by the control segment and is a non-real-time closed-loop control. Furthermore, it does not disclose the differentiated power execution methods and power switching hysteresis mechanisms for different terminal hardware types.

[0006] In the power control process of satellite communication terminals, adjusting the output power of the final-stage power amplifier directly affects the terminal's average power consumption and operating efficiency. Existing technologies reduce the output power of the power amplifier by methods such as fixed supply voltage with adjustable attenuators, digital domain power back-off, gate bias voltage adjustment, and supply voltage adjustment. Different adjustment methods have varying impacts on the DC power consumption and efficiency of the power amplifier.

[0007] In a fixed supply voltage with an adjustable attenuator approach, the power amplifier's supply voltage typically remains constant. When a reduction in output power is needed, the input signal power of the power amplifier is reduced by increasing the attenuation in the RF link. While this method reduces RF output power, the power amplifier still operates at a fixed supply voltage. Therefore, when the output power drops significantly, the power amplifier's efficiency may decrease accordingly. Digital domain power back-off also primarily reduces the output power by decreasing the input signal power of the power amplifier, while the power amplifier's supply voltage typically remains unchanged.

[0008] Gate bias voltage adjustment can reduce static bias current by changing the bias state of the power amplifier, but changes in the bias state may affect the linearity of the power amplifier. By adjusting the supply voltage of the power amplifier or transceiver chip, the power amplifier can be made to operate at the corresponding supply voltage for different output power requirements. However, existing satellite communication terminal power control schemes usually focus primarily on the transmit power required by the link, lacking a power control method that jointly considers link changes during low-Earth orbit satellite overpass, terminal antenna pattern, and the output power and DC power consumption characteristics of the power amplifier under different supply voltages.

[0009] Therefore, it is necessary to provide a method for reducing terminal power consumption during low-Earth orbit satellite overpass. The equivalent omnidirectional radiated power of the terminal is determined based on the satellite position and link changes during overpass, and dynamically adjusted in combination with the efficiency characteristics of the terminal power amplifier. Appropriate power execution methods are adopted for different terminal hardware types to reduce the average power consumption of the terminal while ensuring the quality of the communication link. Summary of the Invention

[0010] The purpose of this invention is to provide a method for reducing terminal power consumption during low-Earth orbit satellite transit, in order to solve the problem that existing low-Earth orbit satellite communication terminals use fixed transmission power or rely solely on closed-loop feedback for power control during satellite transit due to the continuous changes in elevation angle and satellite-to-ground distance, resulting in power waste and high average terminal power consumption during high elevation angle periods.

[0011] To achieve the above objectives, the present invention provides a method for reducing terminal power consumption during the orbital transit of low-Earth orbit satellites, comprising the following steps.

[0012] Step 1, Obtain Location and Time: The terminal obtains its own geographic location coordinates and system time through the GNSS module.

[0013] Step 2: Calculate the satellite position and relative geometric relationship: The terminal reads the pre-stored satellite ephemeris file, calculates the spatial coordinates of the target low-Earth orbit satellite at the current time based on the system time, converts the spatial coordinates into azimuth and elevation angles in the terminal's local horizontal coordinate system, and calculates the spatial distance between the terminal and the target low-Earth orbit satellite.

[0014] Furthermore, the spatial coordinates of the target low-orbit satellite at the current moment are represented by a geocentric geofixed coordinate system or a geocentric inertial coordinate system. The terminal transforms the spatial coordinates of the target low-orbit satellite to the local horizontal coordinate system with the terminal as the origin through coordinate system rotation and translation transformation.

[0015] Step 3, Estimate Path Loss: Based on the elevation angle and spatial distance, and combining the free-space path loss model and the atmospheric attenuation model, estimate the link path loss at the current moment. The link path loss is calculated according to the following formula:

[0016] Where d is the spatial distance between the terminal and the target low-orbit satellite, f is the communication carrier frequency, c is the speed of light, and L_atm(θ) is the atmospheric attenuation corresponding to the elevation angle θ.

[0017] Step 4: Generate an elevation angle-equivalent omnidirectional radiated power optimization mapping table: Based on its own antenna pattern characteristics and power amplifier efficiency characteristics, the terminal pre-generates an elevation angle-equivalent omnidirectional radiated power optimization mapping table for the entire process of low-Earth orbit satellite transit.

[0018] Specifically, the actual antenna gain at different elevation angles is obtained based on the antenna pattern data of the terminal; the minimum equivalent isotropic radiated power required to meet the demodulation threshold is determined based on the satellite communication link budget; the optimal equivalent isotropic radiated power corresponding to different elevation angles is determined based on the minimum equivalent isotropic radiated power and combined with the nonlinear efficiency curve of the power amplifier, with the goal of reducing the total power consumption of the terminal; the optimal equivalent isotropic radiated power is discretized and stored in the non-volatile memory of the terminal.

[0019] Step 5, dynamically adjust the equivalent omnidirectional radiated power: The terminal queries the elevation angle-equivalent omnidirectional radiated power optimization mapping table based on the current elevation angle to determine the target equivalent omnidirectional radiated power, and adopts the corresponding power execution mode according to the terminal type.

[0020] When the terminal is a phased array terminal, the equivalent omnidirectional radiated power is dynamically adjusted by adjusting the supply voltage of the transceiver chip. The phased array terminal pre-calibrates the output power and DC power consumption of the transceiver chip under different supply voltages. Based on the target's equivalent omnidirectional radiated power and the actual antenna gain corresponding to the current elevation angle, the required target output power is determined according to the following formula: P_out_target=EIRP_target-G_ant(θ)+L_feed Where P_out_target is the target output power, EIRP_target is the target equivalent isotropic radiated power, G_ant(θ) is the actual antenna gain corresponding to the current elevation angle, and L_feed is the feeder loss.

[0021] Find the supply voltage with output power no less than the target output power from the pre-calibrated data, and select the supply voltage with the lowest corresponding DC power consumption as the target supply voltage.

[0022] Furthermore, during the production calibration stage of the phased array terminal, the output power and DC power consumption corresponding to different supply voltages are scanned within the operating range of the power supply voltage of the transceiver chip according to a preset voltage step size. The calibration data of power supply voltage-output power-DC power consumption is generated and stored in non-volatile memory. Each transceiver channel of the phased array terminal is calibrated separately.

[0023] The target supply voltage is adjusted through the dynamic voltage adjustment interface of the power management chip; while adjusting the supply voltage, the bias current of the gain amplifier inside the transceiver chip is adjusted simultaneously; when the supply voltage adjustment exceeds the preset range, the supply voltage is adjusted according to the preset slope to avoid transient overshoot during the adjustment process.

[0024] When the terminal is a non-phased array terminal, the RF link gain is adjusted via a digitally controlled adjustable attenuator. The non-phased array terminal calculates the target attenuation of the digitally controlled adjustable attenuator based on the target's equivalent isotropic radiated power, the maximum output power of the power amplifier, the actual antenna gain corresponding to the current elevation angle, and the feeder loss, using the following formula: A_atten = P_max + G_ant(θ) - L_feed - EIRP_target Where A_atten is the target attenuation, P_max is the maximum output power of the power amplifier, G_ant(θ) is the actual antenna gain corresponding to the current elevation angle, L_feed is the feeder loss, and EIRP_target is the target equivalent isotropic radiated power.

[0025] The target attenuation is quantized to the attenuation step value corresponding to the digitally controlled adjustable attenuator, and the attenuation step value is written to the digitally controlled adjustable attenuator through the serial control interface to achieve the adjustment of the RF link gain.

[0026] Furthermore, when the elevation angle is less than the minimum effective elevation angle, the terminal adjusts the RF front-end output power to the minimum or enters a low-power standby state; when the elevation angle is not less than the minimum effective elevation angle and not greater than 60°, the terminal dynamically adjusts the transmit power according to the elevation angle-equivalent omnidirectional radiated power optimization mapping table; when the elevation angle is greater than 60°, the terminal reduces the RF front-end output power to the power that meets the demodulation threshold.

[0027] Step 6, Power switching hysteresis control: Set an elevation hysteresis range near the lowest effective elevation angle, and maintain the current power state within the elevation hysteresis range to prevent frequent power state switching due to measurement errors or elevation fluctuations near the lowest effective elevation angle.

[0028] Step 7, Closed-loop verification and step-by-step power back-off: During the adjustment of the equivalent omnidirectional radiated power, the terminal continuously monitors the signal-to-noise ratio or bit error rate of the received signal, and classifies the signal quality into good signal quality state, critical signal quality state, and poor signal quality state according to the signal-to-noise ratio.

[0029] When the signal quality is good, maintain the current power strategy; when the signal quality is critical, pause further reduction of the transmission power; when the signal quality is poor, increase the transmission power in increments according to the preset power step size, and wait for a preset time after each increase in transmission power to re-detect the signal-to-noise ratio until the signal-to-noise ratio meets the preset requirements or the transmission power reaches the maximum equivalent isotropic radiated power.

[0030] Furthermore, the terminal records the reliable equivalent omnidirectional radiated power corresponding to the current elevation angle during the power increase process, and uses the reliable equivalent omnidirectional radiated power to update the elevation angle-equivalent omnidirectional radiated power optimization mapping table for power control during the subsequent low-Earth orbit satellite overpass process.

[0031] Step 8, Beam Edge Link Budget Constraint: The terminal determines the beam edge gain attenuation based on the angular deviation between the beam pointing direction and the actual direction of the target low-Earth orbit satellite, and incorporates the beam edge gain attenuation when determining the minimum equivalent isotropic radiated power; when the angular deviation exceeds the allowable range, beam realignment is triggered first to bring the angular deviation between the beam pointing direction and the actual direction of the target low-Earth orbit satellite back to the allowable range.

[0032] Compared with the prior art, the present invention has the following beneficial effects.

[0033] First, by calculating the azimuth, elevation, and distance to the target low-orbit satellite using GNSS positioning, satellite ephemeris, and system time, the equivalent omnidirectional radiation power of the terminal is dynamically adjusted according to the link changes during the orbital transit process. This avoids using excessively high transmission power when the elevation angle is high and the path loss is low, thereby reducing the average power consumption of the terminal.

[0034] Second, for phased array terminals, a power supply voltage that meets the target output power and has low DC power consumption is selected by using power supply voltage-output power-DC power consumption calibration data; for non-phased array terminals, the RF link gain is adjusted by using a digitally controlled adjustable attenuator, so that this method can be applied to satellite communication terminals with different hardware types.

[0035] Third, by combining open-loop prediction based on satellite position and elevation angle-equivalent omnidirectional radiated power optimization mapping table with closed-loop verification based on signal-to-noise ratio or bit error rate and step-by-step power back-off, we can not only utilize the predictability of low-Earth orbit satellite orbital position, but also gradually increase the transmission power when the link quality does not meet the requirements, thereby improving the reliability of the communication link.

[0036] Fourth, by setting an elevation hysteresis range, the frequent switching of power states near the lowest effective elevation angle can be reduced; by taking beam edge gain attenuation into the link budget and prioritizing beam realignment when the included angle deviation is too large, it is possible to avoid simply relying on increasing transmit power to compensate for beam pointing deviation.

[0037] Fifth, by recording the reliable equivalent omnidirectional radiated power corresponding to different elevation angles and updating the elevation angle-equivalent omnidirectional radiated power optimization mapping table, the terminal can adjust the subsequent power control based on the link conditions during previous track crossings. Attached Figure Description

[0038] Figure 1 This is a flowchart of a method for reducing terminal power consumption during the orbital transit of a low-Earth orbit satellite, according to an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram illustrating the strategy for adjusting the satellite elevation angle and the equivalent omnidirectional radiated power at the terminal during the orbital passage of a low-Earth orbit satellite.

[0040] Figure 3 This is a block diagram of the internal module structure of a terminal applying the method of the present invention. Detailed Implementation

[0041] The technical solution of the present invention will be further described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention.

[0042] like Figure 1 As shown, this embodiment provides a method for reducing terminal power consumption during the transit of low-Earth orbit (LEO) satellites. By performing satellite position calculation, link path loss estimation, elevation angle-equivalent omnidirectional radiated power optimization mapping table lookup, dynamic power adjustment, closed-loop verification, beam edge constraint, and online updates, the terminal power control during the entire LEO satellite transit process is achieved.

[0043] like Figure 3 As shown, the terminal includes a power management module, a GNSS antenna, a GNSS module, a satellite communication antenna, a transceiver front-end, a main control module, DDR memory, and eMMC memory. The GNSS antenna is connected to the GNSS module, and the GNSS module is connected to the main control module; the satellite communication antenna is connected to the transceiver front-end, and the transceiver front-end is connected to the main control module; the DDR memory and eMMC memory are each connected to the main control module; the power management module supplies power to the power-consuming modules in the terminal. The terminal can be a phased array terminal or a conventional terminal.

[0044] In the power control process of a satellite communication terminal, the output power of the final-stage power amplifier directly affects the terminal's average power consumption and efficiency. Methods to reduce the power amplifier's output power include using a fixed supply voltage with an adjustable attenuator, digital domain power back-off, gate bias voltage adjustment, and drain supply voltage V_dd adjustment. Different adjustment methods have different effects on the power amplifier's DC power consumption and efficiency. This embodiment employs either dynamic supply voltage adjustment or digitally controlled adjustable attenuator adjustment, depending on the terminal hardware type.

[0045] When a fixed supply voltage is used with an adjustable attenuator, the power amplifier's supply voltage V_dd remains at its rated maximum value. The input signal power of the power amplifier is reduced by increasing the attenuation in the preceding RF link. Even with the reduced output power, the decrease in the power amplifier's static bias current and DC power dissipation may still be relatively small. Taking a Class AB power amplifier as an example, when the output power drops 10dB from the saturation point, with V_dd at 5V, the DC power dissipation decreases from 10W to approximately 8.5W, while the RF output power decreases from 4W to 0.4W, and the power-added efficiency decreases from approximately 40% to approximately 4.7%.

[0046] Digital domain power back-off reduces the input signal power of the power amplifier through digital predistortion or digital domain amplitude scaling, allowing the power amplifier to operate in the back-off region, but the supply voltage V_dd remains unchanged. When the digital back-off exceeds 6dB to 8dB, peak factor reduction may also be required. Gate bias voltage adjustment changes the operating class of the power amplifier and reduces the static bias current by adjusting the gate or base bias voltage, but the supply voltage V_dd remains unchanged. However, a large adjustment of the gate bias may affect the adjacent channel leakage ratio and the error vector amplitude, requiring linearization compensation in conjunction with digital predistortion.

[0047] The power supply voltage is dynamically adjusted according to the target output power, changing the power supply voltage of the power amplifier or transceiver chip so that the saturated output power varies with the power supply voltage, and the efficiency curve shifts towards lower or higher output power. Thus, a higher power supply voltage is used during low elevation angle, high power demand phases, and a lower power supply voltage is used during high elevation angle, low power demand phases, allowing the power amplifier to approach the high-efficiency operating range corresponding to the appropriate power supply voltage at different target output power levels.

[0048] Initialization phase: After the terminal is powered on, it activates the GNSS module to obtain the terminal's current geographic location coordinates and precise UTC time. The geographic location coordinates include longitude, latitude, and altitude. At the same time, the terminal loads a valid satellite ephemeris file from non-volatile memory. The satellite ephemeris file can be in BeiDou ephemeris format or GPS ephemeris format.

[0049] The terminal reads its own model identifier to determine whether it is a phased array terminal or a regular terminal, and loads the antenna pattern parameter G_ant(θ), power amplifier efficiency curve η(EIRP), and elevation angle-equivalent omnidirectional radiated power optimization mapping table corresponding to the terminal type. If the elevation angle-equivalent omnidirectional radiated power optimization mapping table has not yet been generated or needs to be updated, a new elevation angle-equivalent omnidirectional radiated power optimization mapping table is generated according to the mapping table generation method described later.

[0050] Satellite position and relative geometric relationship calculation stage: The terminal calculates the geocentric-ground-fixed coordinates or geocentric-inertial coordinates of the target low-Earth orbit satellite at the current moment using a satellite position calculation algorithm based on the current UTC time T and satellite ephemeris data provided by the GNSS module. Taking the geocentric-ground-fixed coordinates as an example, the spatial coordinates of the target low-Earth orbit satellite are (X_s, Y_s, Z_s), and the spatial coordinates of the terminal itself are (X_u, Y_u, Z_u). The spatial distance d between the terminal and the target low-Earth orbit satellite is calculated according to equation (1): (1) By performing coordinate system rotation and translation transformations, the spatial coordinates of the target low-Earth orbit satellite are transformed to the local horizontal coordinate system with the terminal as the origin, i.e., the northeast-sky coordinate system, to obtain the real-time azimuth angle φ and elevation angle θ of the target low-Earth orbit satellite relative to the terminal. The elevation angle θ is calculated based on the altitude angle of the target low-Earth orbit satellite in the local horizontal coordinate system.

[0051] Path loss estimation stage The terminal calculates the free space path loss L_fs at the current moment according to the free space path loss model. The free space path loss L_fs is calculated according to equation (2): (2) In equation (2), d is the spatial distance between the terminal and the target low-orbit satellite, f is the communication carrier frequency, and c is the speed of light.

[0052] The terminal looks up the corresponding atmospheric attenuation L_atm(θ) based on the elevation angle θ. Atmospheric attenuation includes tropospheric gas attenuation, water vapor attenuation, and ionospheric scintillation loss. The total link path loss L(θ) at the current moment is calculated according to equation (3): (3) Elevation Angle—Equivalent Isotropic Radiated Power Optimization Mapping Table Generation Stage Based on its own antenna pattern characteristics and power amplifier efficiency characteristics, the terminal pre-generates an elevation angle-equivalent omnidirectional radiated power optimization mapping table for the entire process of the target low-Earth orbit satellite's orbital transit.

[0053] First, based on the antenna pattern data of the terminal, obtain the actual antenna gain G_ant(θ) at different elevation angles θ. Second, based on the satellite communication link budget, calculate the minimum EIRP value required to satisfy the demodulation threshold SNR_th, according to equation (4): (4) In equation (4), k is the Boltzmann constant, T is the system noise temperature, B is the signal bandwidth, and Margin is the link margin, which includes beam pointing error and fading reserve.

[0054] Based on EIRP_min(θ), and combined with the nonlinear efficiency curve η(EIRP) of the power amplifier, the optimal equivalent isotropic radiated power EIRP_opt(θ) corresponding to different elevation angles is determined with the goal of reducing the total power consumption of the terminal. The corresponding optimization objective is expressed according to equation (5): (5) In equation (5), P_other represents the power consumption of modules other than the power amplifier in the terminal. The optimization process satisfies the constraint that EIRP is not less than EIRP_min(θ) and not greater than the terminal's maximum equivalent isotropic radiated power EIRP_max.

[0055] When optimizing the entire overpass process, corresponding weights are set according to the duration of each elevation angle interval during the overpass process, with the weighted average power consumption of the entire overpass process as the optimization objective. The obtained EIRP_opt(θ) is discretized according to the preset elevation angle interval to form an elevation angle-equivalent isotropic radiated power optimization mapping table, which is stored in non-volatile memory.

[0056] The mapping table generation process considers not only the instantaneous power consumption at a single operating point, but also the time proportions of the low-elevation, medium-elevation, and high-elevation segments during a single track crossing. The terminal calculates the minimum required equivalent omnidirectional radiated power and candidate power operating points for each discrete elevation angle, and then weights the DC power consumption according to the duration of each discrete elevation angle to reduce the average total power consumption throughout the track crossing process.

[0057] For phased array terminals, the mapping table generation process calls the power supply voltage-output power-DC power consumption calibration data and selects the power supply voltage with lower DC power consumption among the operating points that meet the link budget constraints. For ordinary terminals, the mapping table generation process determines the attenuation amount corresponding to each discrete elevation angle based on the maximum output power of the power amplifier, antenna gain, feeder loss and attenuation step of the digitally controlled adjustable attenuator.

[0058] like Figure 2As shown, the elevation angle-equivalent isotropic radiated power optimization mapping relationship exhibits a nonlinear variation. In the low elevation angle segment, from the lowest effective elevation angle θ_min to 20°, the equivalent isotropic radiated power increases rapidly with elevation angle to compensate for significant path loss and insufficient antenna gain. In the medium elevation angle segment, from 20° to 60°, the equivalent isotropic radiated power smoothly transitions according to the optimized mapping relationship. In the high elevation angle segment, greater than 60°, the equivalent isotropic radiated power slowly decreases to the power required to meet the demodulation threshold.

[0059] Mapping table lookup and target equivalent isotropic radiated power determination stage The terminal uses the current elevation angle θ as an index to query the elevation angle-equivalent isotropic radiated power optimization mapping table to obtain the target equivalent isotropic radiated power EIRP_target. If the current elevation angle is within the hysteresis interval corresponding to the lowest effective elevation angle θ_min, the power state of the previous moment remains unchanged; if the current elevation angle is outside the hysteresis interval, the target equivalent isotropic radiated power is updated according to the elevation angle-equivalent isotropic radiated power optimization mapping table.

[0060] Dynamic power execution mode of phased array terminal When the terminal is a phased array terminal, the equivalent omnidirectional radiation power is dynamically adjusted by adjusting the supply voltage V_dd of the core transceiver chip. The terminal pre-calibrates the output power P_out(V_dd) and DC power consumption P_dc(V_dd) of the transceiver chip under different supply voltages V_dd, and calculates the efficiency η(V_dd) under each supply voltage according to equation (6): η(V_dd)=P_out(V_dd) / P_dc(V_dd) (6) During the terminal production calibration stage, each transceiver channel is scanned within a supply voltage range of 0.6V to 1.2V in 0.05V steps. The output power P_out(V_dd) and DC power consumption P_dc(V_dd) corresponding to each supply voltage are recorded, generating supply voltage-output power-DC power consumption calibration data, which is stored in non-volatile memory. Each transceiver channel is calibrated separately to compensate for process deviations between different channels.

[0061] Based on the target equivalent isotropic radiated power EIRP_target, the actual antenna gain G_ant(θ) corresponding to the current elevation angle, and the feed loss L_feed, the target output power P_out_target required by the transceiver chip is calculated according to equation (7): P_out_target=EIRP_target-G_ant(θ)+L_feed(7) In the supply voltage-output power-DC power consumption calibration data, all supply voltages that satisfy P_out(V_dd) not less than P_out_target are searched, and the supply voltage with the smallest corresponding DC power consumption P_dc(V_dd) is selected as the target supply voltage V_dd_opt. If multiple supply voltages correspond to the same output power, the supply voltage with the higher efficiency η(V_dd) is selected. In this way, the DC power consumption of the transceiver chip is reduced while meeting the target equivalent isotropic radiation power.

[0062] The target supply voltage is adjusted via the dynamic voltage regulation interface of the power management chip, with a voltage adjustment accuracy of 10mV and a settling time of less than 100μs. Simultaneously, the bias current of the gain amplifier within the transceiver chip is adjusted to ensure that the output power stability and linearity meet requirements. When the supply voltage adjustment exceeds 50mV, a slope control method is used with an adjustment slope of 1V / ms to avoid transient overshoot.

[0063] Based on the calibration data under different supply voltages, two-dimensional efficiency data can also be established with output power P_out and supply voltage V_dd as parameters. For a given target output power, the supply voltage with the minimum DC power consumption P_dc can be found in the two-dimensional efficiency data, and the search result can be used to generate and query the elevation angle-equivalent omnidirectional radiated power optimization mapping table.

[0064] When the supply voltage is dynamically adjusted, the saturated output power of the power amplifier changes with the supply voltage, and the efficiency curve of the power amplifier shifts accordingly towards the desired output power. This allows the power amplifier to operate in a relatively high-efficiency region even at high elevation angles and low output power requirements. Compared to reducing output power solely through input signal backoff at a fixed supply voltage, this method can further reduce the DC power consumption of the power amplifier.

[0065] In one embodiment illustrating efficiency variation, a GaAs power amplifier with a rated supply voltage of 5V is used. When the supply voltage is fixed at 5V, the saturated output power P_sat is 36dBm, or approximately 4W, and the maximum power-added efficiency is 45%. When the output power drops from the saturated output power to 26dBm, or approximately 0.4W, the power-added efficiency decreases to approximately 5.2%, and the DC power consumption calculated based on the output power and power-added efficiency is approximately 7.7W.

[0066] When using dynamic power supply voltage adjustment, if the output power corresponding to the target's equivalent isotropic radiation power is 26dBm, reducing the power supply voltage from 5V to 3.2V reduces the saturated output power of the power amplifier at 3.2V to 32dBm, or approximately 1.6W. At an output power of 26dBm, the power-added efficiency can reach approximately 28%, corresponding to a DC power consumption of approximately 1.43W, which is about 18.6% of the DC power consumption under a fixed 5V power supply voltage.

[0067] The aforementioned supply voltage change causes the power-added efficiency-output power curve to shift towards lower output power. When the supply voltage decreases from 5V to 3.2V, the output power corresponding to the peak power-added efficiency shifts from 36dBm to 32dBm, the peak power-added efficiency changes from 45% to approximately 38%, and the power-added efficiency at the 26dBm output power point increases from 5.2% to approximately 28%.

[0068] In another phased array transceiver chip embodiment, the supply voltage is adjusted within the range of 0.6V to 1.2V. A supply voltage close to 1.2V is used during low elevation angles, while the supply voltage is reduced to approximately 0.8V during high elevation angles. Although the saturated output power decreases after the supply voltage is reduced, the efficiency during high elevation angles can be maintained at 25% to 30%, and the DC power consumption is reduced by more than 40% compared to the method using a fixed maximum supply voltage.

[0069] Comparison of operating points of different power regulation methods Taking a GaAs power amplifier with a rated supply voltage of 5V and an operating frequency of 17.7GHz as an example, we compare the fixed supply voltage method, the fixed supply voltage combined with an adjustable attenuator method, the gate bias voltage adjustment method, and the dynamic supply voltage adjustment method.

[0070] At low elevation angles, the target output power is 35dBm, or approximately 3.2W. The power-added efficiency (PEP) is 42% with a DC power consumption of 7.6W using a fixed 5V supply voltage. The PEP with a fixed 5V supply voltage and an adjustable attenuator is 42%, with a total power consumption of 8.1W after accounting for 0.5W attenuator insertion loss. The PEP after bias adjustment using a gate bias voltage adjustment method is 45%, with a DC power consumption of 7.1W. The dynamic supply voltage adjustment method uses a full 5V supply in this stage, achieving a PEP of 42% and a DC power consumption of 7.6W.

[0071] At high elevation angles, the target output power is 26dBm, or approximately 0.4W. The power-added efficiency (PEP) is 5.2% and the DC power consumption is 7.7W with a fixed 5V supply voltage. The PEP is also 5.2% with an adjustable attenuator, and the power amplifier's DC power consumption is 7.7W. Including the 0.5W attenuator insertion loss, the total power consumption is 8.2W. With gate bias voltage adjustment, the PEP is 12% and the DC power consumption is 3.3W. With dynamic supply voltage adjustment to 3.2V, the PEP is 28% and the DC power consumption is 1.43W.

[0072] In this comparative embodiment, when using dynamic power supply voltage adjustment at high elevation angles, the DC power consumption of the power amplifier is approximately 18.6% of that of the fixed power supply voltage method, 17.4% of the total power consumption of the fixed power supply voltage combined with an adjustable attenuator method, and 43.3% of the DC power consumption of the gate bias voltage adjustment method. Considering the 90% efficiency of the power management chip, approximately 2.5W of baseband processor power consumption, and approximately 1.0W of power consumption of other RF front-end devices, the total system power consumption of the dynamic power supply voltage adjustment method at high elevation angles is approximately 5.2W, while the total system power consumption of the fixed power supply voltage method is approximately 11.5W.

[0073] The high elevation angle and low power demand phase accounts for over 50% of the typical rail crossing process. Dynamic power supply voltage adjustment reduces total system power consumption by approximately 54.8% compared to a fixed power supply voltage approach during the high elevation angle phase. In the traditional fixed power supply voltage approach, the power amplifier efficiency is approximately 35% to 40% during the low elevation angle phase, and approximately 15% to 20% after output power reduction during the high elevation angle phase; with dynamic power supply voltage adjustment, the efficiency during the high elevation angle phase can be maintained at 25% to 30%.

[0074] Dynamic power execution mode of ordinary terminals When the terminal is a standard terminal, the RF link gain is adjusted via a digitally controlled adjustable attenuator (DAT) located in the RF front-end. The DAT can be an HMC424, HMC624, or other 6-bit or 7-bit DAT, with an attenuation range of 0 to 31.5 dB or 0 to 63 dB, and attenuation steps of 0.5 dB or 1 dB. The control register is written via an SPI or I²C interface, with a write time of less than 1 μs. The typical insertion loss of the DAT is 1 dB to 2 dB, which is factored into the link budget. When the phased array terminal already achieves fine power control through power supply voltage adjustment, the DAT serves as an auxiliary fine-tuning device with 0.5 dB steps; when a standard terminal relies entirely on the DAT for power control, 1 dB steps are used to cover a larger dynamic range.

[0075] Based on the target's equivalent isotropic radiated power EIRP_target, the power amplifier's maximum output power P_max, the actual antenna gain G_ant(θ) corresponding to the current elevation angle, and the feed loss L_feed, the target attenuation A_atten is calculated according to equation (8): A_atten = P_max + G_ant(θ) - L_feed - EIRP_target (8) The relationship between the attenuation of the numerically controlled adjustable attenuator and the output power of the power amplifier is expressed by equation (9): P_out = P_max - A_atten(9) The calculated target attenuation is quantized to the most recent attenuation step value of the CNC adjustable attenuator. If the target attenuation is less than 0, the attenuation is set to 0dB and an insufficient power alarm is triggered; if the target attenuation is greater than the maximum attenuation of the CNC adjustable attenuator, the attenuation is set to the maximum value and the system is marked as low power mode.

[0076] The terminal writes the quantized attenuation value to the control register of the numerically controlled adjustable attenuator via the SPI or I²C interface. To increase the attenuation to reduce output power, the numerically controlled adjustable attenuator is adjusted directly. To decrease the attenuation to increase output power, the reflected power and VSWR of the power amplifier are first detected. If the VSWR is greater than 2.5, the adjustment is paused and an alarm is issued. When a single attenuation change exceeds 3dB, the target change is divided into 2 to 3 steps for gradual adjustment, with a time interval of 50ms between adjacent steps.

[0077] In a typical terminal, the power amplifier's output power is reduced by decreasing the signal power at the power amplifier's input. The power amplifier's supply voltage and DC bias remain constant; the reduction in terminal power consumption primarily stems from the decrease in dynamic current at the power amplifier's output stage and the power consumption of the preceding driver amplifier.

[0078] In a typical terminal power consumption analysis example, the decrease in output stage dynamic current due to the reduction in power amplifier output power accounts for approximately 60% of the energy savings, and the decrease in power consumption of the pre-amplifier accounts for approximately 40% of the energy savings. The average power saving rate for a typical terminal using a digitally controlled adjustable attenuator is approximately 20.0%, while the average power saving rate for a phased array terminal using a dynamic power supply voltage adjustment method is approximately 35.2%.

[0079] The numerically controlled adjustable attenuator reduces the signal power reaching the power amplifier input through pre-stage attenuation, while keeping the power amplifier's supply voltage and DC bias constant. Dynamic supply voltage adjustment, on the other hand, changes the power amplifier's supply voltage, causing its efficiency curve to vary accordingly. Both methods determine the target power based on an elevation angle-equivalent isotropic radiated power optimization mapping table, but they are suitable for different terminal hardware types.

[0080] Elevation zone control and hysteresis mechanism When the elevation angle θ is less than the minimum effective elevation angle θ_min, the target low-Earth orbit satellite is determined to be located in an area outside the effective beam coverage zone, and the terminal adjusts the RF front-end output power to the minimum value or enters a low-power standby state. When θ_min is not greater than θ and θ is not greater than 60°, the terminal dynamically adjusts the power according to the elevation angle-equivalent isotropic radiated power optimization mapping table; the lower the elevation angle, the higher the EIRP. When θ is greater than 60°, the target low-Earth orbit satellite is determined to be located in a high elevation angle coverage zone, and the terminal reduces the RF front-end output power to the power that meets the demodulation threshold.

[0081] For phased array terminals, the minimum effective elevation angle θ_min is the larger of the minimum scannable elevation angle θ_scan_min and the antenna beam half-power angle θ_beam_3dB; for fixed antenna terminals, the minimum effective elevation angle θ_min is determined based on the antenna beam half-power angle θ_beam_3dB.

[0082] To prevent frequent power switching near the lowest effective elevation angle due to measurement errors or minor fluctuations in elevation angle, an elevation hysteresis interval of Δθ = ±3° is set near θ_min. This hysteresis interval is determined by comprehensively considering GNSS positioning error, satellite ephemeris error, and terminal attitude fluctuations. Specifically, the GNSS positioning error is less than 5m, the elevation angle calculation error caused by ephemeris error is less than 1°, and the elevation angle change caused by terminal attitude fluctuations is less than 2°. When the elevation angle is within (θ_min - Δθ, θ_min + Δθ), the terminal maintains its current power state.

[0083] Closed-loop verification and step-by-step power back-off stage While dynamically adjusting the power, the terminal continuously monitors the signal-to-noise ratio (SNR) or bit error rate (BER) of the downlink received signal, and classifies the signal quality into three states based on the relationship between the SNR and the demodulation threshold (SNR_th): good signal quality (SNR_good), critical signal quality (SNR_margin), and poor signal quality (SNR_bad).

[0084] When the SNR is greater than SNR_th + 3dB, it is determined to be in the SNR_good state, and the terminal maintains the current power strategy; when the SNR is greater than SNR_th but not greater than SNR_th + 3dB, it is determined to be in the SNR_margin state, and the terminal suspends further reduction of transmission power and maintains the current power; when the SNR is not greater than SNR_th, it is determined to be in the SNR_bad state, and the terminal triggers the step-by-step power back-off procedure.

[0085] In the SNR_bad state, the transmit power is increased incrementally according to a preset power step size P_step. P_step is 0.5dB for phased array terminals and 1dB for ordinary terminals. After each power increase, a wait of T_wait = 100ms is performed before re-evaluating the signal-to-noise ratio. When the SNR recovers to a value greater than SNR_th + Margin, the power increase stops. If the transmit power reaches the terminal's maximum equivalent isotropic radiated power EIRP_max but still fails to meet the threshold, a link interruption is determined, and a link reconstruction process is triggered.

[0086] After each increase or decrease in transmit power, wait at least 50ms for the stabilization time T_stable to allow the transceiver link and modem to reach a stable state before performing the next signal-to-noise ratio measurement or power adjustment.

[0087] During the step-back power process, if the equivalent omnidirectional radiated power corresponding to the current elevation angle in the elevation angle-equivalent omnidirectional radiated power optimization mapping table is insufficient to maintain link quality, the current elevation angle and the actual measured reliable equivalent omnidirectional radiated power are recorded, and the elevation angle-equivalent omnidirectional radiated power optimization mapping table is updated using the reliable equivalent omnidirectional radiated power for power control during subsequent track crossings.

[0088] The aforementioned closed-loop verification is performed by the terminal based on local signal-to-noise ratio or bit error rate measurements, without relying on continuous power control words from the satellite side. When downlink power control signaling is interrupted or weak real-time transmission occurs, the terminal still performs power maintenance, pauses power reduction, or incremental increases according to the three threshold states of SNR_good, SNR_margin, and SNR_bad.

[0089] The system combines three-level threshold control with step-by-step incrementing. It retains the current link margin when signal quality is critical, gradually increases transmit power when signal quality falls below the demodulation threshold, and waits for link stabilization after each adjustment. By recording the elevation angle and reliable equivalent isotropic radiated power at the time of power increment, the terminal can perform online correction of the statically generated elevation angle-equivalent isotropic radiated power optimization mapping table.

[0090] Beam edge link budget constraint phase The terminal obtains the angular deviation θ_offset between the terminal beam pointing and the actual direction of the target low-Earth orbit satellite in real time through attitude sensors or by estimating the signal angle of arrival. Attitude sensors include IMUs or gyroscopes. The terminal obtains the beam edge gain attenuation G_edge(θ_offset) corresponding to the angular deviation θ_offset by looking up a table based on the antenna pattern data.

[0091] When determining the minimum equivalent isotropic radiated power, in addition to free-space path loss and atmospheric attenuation, other link losses and beam edge gain attenuation are also taken into account. The complete link budget constraint is expressed by equation (10): (10) In equation (10), L_other represents other link losses, and G_edge(θ_offset) represents beam edge gain attenuation. The link margin is dynamically adjusted according to the angle deviation θ_offset, taking 3dB when the angle deviation is small and 6dB when the angle deviation is large.

[0092] When the included angle deviation θ_offset exceeds the maximum allowable value (which can be the antenna beam half-power angle), the terminal prioritizes triggering beam realignment. For phased array terminals, realignment is performed by adjusting the phased array beam pointing; for terminals with mechanical rotation mechanisms, realignment is performed by adjusting the mechanical rotation angle of the antenna. After beam realignment is completed and the included angle deviation returns to the allowable range, power adjustment is then performed to avoid compensating for beam pointing deviation solely by increasing transmit power.

[0093] Power supply voltage efficiency surface and average power consumption optimization Based on the calibration results under different output powers P_out and different supply voltages V_dd, a two-dimensional efficiency surface of drain efficiency η(P_out, V_dd) is established. For a given output power target, the DC power consumption is determined according to equation (11): P_dc(P_out, V_dd)=P_out / η(P_out, V_dd) (11) The system searches a two-dimensional efficiency surface for the supply voltage that minimizes DC power consumption under a given output power target, and uses the found supply voltage as the target supply voltage at the corresponding elevation angle. This two-dimensional efficiency surface is associated with an elevation angle-equivalent omnidirectional radiated power optimization mapping table, so that each discrete elevation angle corresponds to a supply voltage operating point that satisfies the link budget constraint and has low DC power consumption.

[0094] When the weighted average power consumption throughout the over-orbit process is used as the optimization objective, the objective function is min E[P_dc(θ)], θ∈[θ_min, 90°]. The weight of each elevation angle interval is determined based on the time proportion of the target low-Earth orbit satellite within the corresponding elevation angle interval. The optimization process jointly considers link budget constraints, terminal maximum equivalent isotropic radiated power constraints, power amplifier efficiency surfaces, and the time weights of each elevation angle interval.

[0095] According to the load line relationship of the power amplifier, the optimal load impedance R_opt, the supply voltage V_dd, and the saturated output power P_sat satisfy the following relationship: R_opt∝V_dd² / P_sat.

[0096] When the supply voltage decreases, the saturated output power of the power amplifier decreases accordingly, and the power-added efficiency-output power curve shifts towards lower power. The terminal utilizes this characteristic to adjust the supply voltage according to the output power requirements at different elevation angles during track crossing, ensuring the power amplifier operates in the higher efficiency region corresponding to the current supply voltage.

[0097] Track crossing power consumption verification example In a phased array terminal simulation embodiment, the terminal uses an 8×8 phased array and operates in the Ku band. The visibility time for a single track crossing is approximately 8 minutes, with an elevation angle ranging from 5° to 90°. The average power consumption during track crossing is 12.5W under fixed power mode, and 8.1W after adopting dynamic power supply voltage adjustment mode, representing an average power saving rate of 35.2%.

[0098] In this phased array terminal simulation embodiment, the power consumption in the high elevation angle segment decreased from 12.5W to 5.2W, with a power saving rate of 58.4%; the power saving rate in the low elevation angle segment was approximately 8.3%; and the power saving rate in the medium elevation angle segment was approximately 28.7%.

[0099] In a typical terminal simulation example, the terminal uses a fixed antenna and a digitally controlled adjustable attenuator. The average power consumption during track crossing is 8.0W under the fixed power mode, and the average power consumption during track crossing is 6.4W after adjusting the RF link gain using the digitally controlled adjustable attenuator, with an average power saving rate of 20.0%.

[0100] Based on 12 track overruns per day, according to the following formula... (12) The phased array terminal saves an average of 7.04Wh of energy per day, while the ordinary terminal saves an average of 2.56Wh per day. For a 10Wh battery, the phased array terminal extends the battery life by approximately 6.5 hours, while the ordinary terminal extends the battery life by approximately 4.7 hours.

[0101] To compare the power consumption of different power regulation methods throughout the track crossing process, the following conditions were used: 8×8 phased array, Ku band, track crossing time of approximately 8 minutes, and elevation angle range of 5° to 90°. With a fixed 5V supply voltage and no power regulation, the power consumption was 12.5W in the low, medium, and high elevation angle segments, with an average track crossing power consumption of 12.5W. The energy consumption per track crossing was 1.67Wh, and a 10Wh battery could support 6 track crossings.

[0102] With a fixed 5V power supply and digital domain power back-off, the power consumption is 12.5W at low elevation angles, 11.8W at medium elevation angles, and 11.2W at high elevation angles. The average power consumption for track crossing is 11.8W, and the energy consumption for a single track crossing is 1.57Wh. A 10Wh battery can support 6.4 track crossings, with an average power saving rate of 5.6%.

[0103] With a fixed 5V power supply and an adjustable attenuator, the power consumption is 12.8W at low elevation angles, 10.5W at medium elevation angles, and 8.5W at high elevation angles. The average power consumption for track crossing is 10.0W, and the energy consumption for a single track crossing is 1.33Wh. A 10Wh battery can support 7.5 track crossings, with an average power saving rate of 20.0%.

[0104] When using gate bias voltage regulation, the power consumption is 11.8W at low elevation angle, 9.2W at medium elevation angle, and 6.6W at high elevation angle. The average power consumption during rail crossing is 8.8W, and the energy consumption per rail crossing is 1.17Wh. A 10Wh battery can support 8.5 rail crossings, with an average power saving rate of 29.6%.

[0105] When using dynamic power supply voltage adjustment, the power consumption is 11.5W at low elevation angle, 8.8W at medium elevation angle, and 5.2W at high elevation angle. The average power consumption for rail crossing is 8.1W, and the energy consumption for a single rail crossing is 1.08Wh. A 10Wh battery can support 9.3 rail crossings, with an average power saving rate of 35.2%.

[0106] Under the above comparative conditions, the average power saving rate of the dynamic power supply voltage adjustment method is higher than that of the fixed power supply voltage with adjustable attenuator method, the gate bias voltage adjustment method, and the digital domain power back-off method. Calculated based on 12 rail passes per day, the dynamic power supply voltage adjustment method saves an average of 7.04 Wh per day compared to the fixed power supply voltage method, 3.04 Wh per day compared to the adjustable attenuator method, and 1.12 Wh per day compared to the gate bias voltage adjustment method.

[0107] Full-process loop of track crossing The terminal performs satellite position calculation, elevation angle update, path loss estimation, mapping table lookup, dynamic power adjustment, closed-loop verification, and beam edge constraint cyclically according to a fixed period. The fixed period can be 1 second or 0.5 seconds.

[0108] When the elevation angle of the target low-Earth orbit satellite drops below the minimum effective elevation angle θ_min and remains below it for more than the time corresponding to the hysteresis interval, it is determined that the target low-Earth orbit satellite has left the area, and the terminal adjusts its power to the minimum value or enters standby mode. The terminal waits for the next low-Earth orbit satellite to enter the effective communication range before repeating the above process.

[0109] This embodiment combines open-loop power control formed by ephemeris prediction and elevation angle-equivalent omnidirectional radiated power optimization mapping table with closed-loop verification formed by signal-to-noise ratio or bit error rate threshold judgment and step-by-step power backoff, so as to maintain communication quality in edge scenarios while taking advantage of the predictability of low-Earth orbit satellite orbits.

[0110] This embodiment is based on existing software algorithms in the terminal and power supply voltage adjustment interface or digitally controlled adjustable attenuator control interface. For terminals with corresponding hardware control interfaces, satellite ephemeris analysis, mapping table lookup, power supply voltage selection, attenuation calculation, three-level threshold judgment, and online update programs can be loaded through software upgrades.

[0111] The terminal adapts to different satellite constellations, communication frequency bands, and usage scenarios by recording and updating the elevation angle-equivalent isotropic radiated power optimization mapping table online. For battery-powered handheld terminals, based on 10 to 15 orbital passes per day, the average daily battery life can be extended by 3 to 8 hours.

[0112] This invention employs nonlinear predictive power control throughout the entire low-Earth orbit (LEO) satellite transit process. It dynamically adjusts the terminal's equivalent omnidirectional radiation power based on changes in satellite position, elevation angle, satellite-to-ground distance, and link path loss. This prevents the terminal from maintaining high transmission power at high elevation angles and with low path loss, thereby reducing the terminal's average power consumption throughout the LEO satellite transit process.

[0113] For phased array terminals, by using calibration data on supply voltage, output power, and DC power consumption, a supply voltage with lower DC power consumption is selected among those that meet the target's equivalent isotropic radiation power requirements. This allows the power amplifier's efficiency curve to vary with the supply voltage, enabling the power amplifier to operate in a relatively high-efficiency region under different output power demands. Under simulation conditions of an 8×8 phased array, Ku band, single overpass time of approximately 8 minutes, and elevation angle range of 5° to 90°, the terminal's average overpass power consumption can be reduced from 12.5W under fixed power mode to 8.1W, achieving an average power saving rate of 35.2%. Among these, the power consumption during high elevation angle stages can be reduced from 12.5W to 5.2W, achieving a power saving rate of 58.4%.

[0114] For ordinary terminals, by adjusting the RF link gain through a digitally controlled adjustable attenuator and determining the attenuation amount based on the target equivalent isotropic radiated power, the maximum output power of the power amplifier, the antenna gain, and the feeder loss, dynamic power control can be achieved without changing the original power amplifier power supply method of the terminal. Under simulation conditions using a fixed antenna and a digitally controlled adjustable attenuator in an ordinary terminal, the average power consumption over track can be reduced from 8.0W to 6.4W, achieving an average power saving rate of 20.0%.

[0115] This invention can improve the battery life of battery-powered terminals. Based on 12 track crossings per day, the phased array terminal can achieve an average daily energy saving of 7.04Wh, while a regular terminal can achieve 2.56Wh. For a 10Wh battery, the phased array terminal's battery life can be extended by approximately 6.5 hours, and the regular terminal's by approximately 4.7 hours. Therefore, it is suitable for applications with high battery life requirements, such as portable handheld terminals, emergency communication backpacks, and low-power IoT terminals.

[0116] This invention combines open-loop prediction based on GNSS positioning, satellite ephemeris, and elevation angle-equivalent omnidirectional radiated power optimization mapping table with three-level threshold judgment based on signal-to-noise ratio or bit error rate and step-by-step power backoff. This allows for both the use of the predictability of low-Earth orbit satellite orbital position to adjust the transmission power in advance and the gradual increase of transmission power when the actual link quality is below the demodulation threshold, thereby balancing the reduction of terminal power consumption and the guarantee of communication link reliability.

[0117] This invention employs differentiated power execution methods for different terminal hardware types. Phased array terminals reduce DC power consumption by dynamically adjusting the power supply voltage of the transceiver chip, while ordinary terminals adjust the RF link gain through a digitally controlled adjustable attenuator, thus exhibiting good terminal compatibility. For terminals with corresponding hardware control interfaces, satellite position calculation, mapping table lookup, power supply voltage selection, attenuation calculation, and closed-loop verification programs can be added via software upgrades.

[0118] This invention reduces frequent power switching near the lowest effective elevation angle by using an elevation hysteresis interval. By incorporating beam edge gain attenuation into the link budget and prioritizing beam realignment when beam pointing deviation is excessive, it can reduce the impact of measurement errors, attitude fluctuations, and beam pointing deviation on power control stability. Simultaneously, by recording the reliable equivalent omnidirectional radiated power that maintains link quality at different elevation angles and updating the elevation-equivalent omnidirectional radiated power optimization mapping table, the terminal can perform online adaptive optimization based on actual link conditions during past track crossings.

[0119] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for reducing terminal power consumption during low-Earth orbit satellite overpass, characterized in that, Includes the following steps: The terminal obtains its own geographic location coordinates and system time through the GNSS module; The terminal reads the pre-stored satellite ephemeris file, calculates the spatial coordinates of the target low-orbit satellite at the current time based on the system time, converts the spatial coordinates into azimuth and elevation angles in the terminal's local horizontal coordinate system, and calculates the spatial distance between the terminal and the target low-orbit satellite. Based on the elevation angle and the spatial distance, and combining the free space path loss model and the atmospheric attenuation model, the link path loss at the current moment is estimated. The terminal pre-generates an elevation angle-equivalent omnidirectional radiated power optimization mapping table for the entire process of low-Earth orbit satellite overpass based on its own antenna pattern characteristics and power amplifier efficiency characteristics. The terminal queries the elevation angle-equivalent omnidirectional radiated power optimization mapping table according to the current elevation angle to determine the target equivalent omnidirectional radiated power, and adopts the corresponding power execution mode according to the terminal type. Specifically, the phased array terminal dynamically adjusts the equivalent omnidirectional radiated power by adjusting the power supply voltage of the transceiver chip, while the non-phased array terminal adjusts the RF link gain by a digitally controlled adjustable attenuator. During the adjustment of the equivalent omnidirectional radiation power, the terminal monitors the signal-to-noise ratio or bit error rate of the received signal, and when the signal-to-noise ratio or bit error rate does not meet the preset threshold requirements, it increases the transmission power in increments according to the preset power step size.

2. The method for reducing terminal power consumption during low-Earth orbit satellite overpass according to claim 1, characterized in that, The link path loss is calculated according to the following formula: ； Where d is the spatial distance between the terminal and the target low-orbit satellite, f is the communication carrier frequency, c is the speed of light, and L_atm(θ) is the atmospheric attenuation corresponding to the elevation angle θ.

3. The method for reducing terminal power consumption during low-Earth orbit satellite transit according to claim 1, characterized in that, Generating the elevation angle-equivalent isotropic radiated power optimization mapping table includes: obtaining the actual antenna gain at different elevation angles based on the antenna pattern data of the terminal; determining the minimum equivalent isotropic radiated power required to meet the demodulation threshold based on the satellite communication link budget; determining the optimal equivalent isotropic radiated power corresponding to different elevation angles based on the minimum equivalent isotropic radiated power and the nonlinear efficiency curve of the power amplifier, with the goal of reducing the total power consumption of the terminal; and discretizing the optimal equivalent isotropic radiated power and storing it in the non-volatile memory of the terminal.

4. The method for reducing terminal power consumption during low-Earth orbit satellite overpass according to claim 1, characterized in that, The phased array terminal pre-calibrates the output power and DC power consumption of the transceiver chip under different power supply voltages; determines the required target output power based on the target equivalent omnidirectional radiation power and the actual antenna gain corresponding to the current elevation angle; searches for power supply voltages with output power not lower than the target output power in the pre-calibrated data, and selects the power supply voltage with the lowest corresponding DC power consumption as the target power supply voltage.

5. The method for reducing terminal power consumption during low-Earth orbit satellite transit according to claim 4, characterized in that, During the production calibration stage of the phased array terminal, the transceiver chip is scanned within the operating range of the power supply voltage according to a preset voltage step size. The output power and DC power consumption corresponding to different power supply voltages are recorded, and power supply voltage-output power-DC power consumption calibration data are generated and stored in non-volatile memory. Each transceiver channel of the phased array terminal is calibrated separately.

6. The method for reducing terminal power consumption during low-Earth orbit satellite transit according to claim 4, characterized in that, The target supply voltage is adjusted through the dynamic voltage adjustment interface of the power management chip; while adjusting the supply voltage, the bias current of the gain amplifier inside the transceiver chip is adjusted simultaneously; when the supply voltage adjustment exceeds the preset range, the supply voltage is adjusted according to the preset slope.

7. The method for reducing terminal power consumption during low-Earth orbit satellite transit according to any one of claims 1 to 3, characterized in that, The non-phased array terminal calculates the target attenuation of the numerically controlled adjustable attenuator based on the target equivalent omnidirectional radiated power, the maximum output power of the power amplifier, the actual antenna gain corresponding to the current elevation angle, and the feeder loss; quantizes the target attenuation to the attenuation step value corresponding to the numerically controlled adjustable attenuator, and writes the attenuation step value to the numerically controlled adjustable attenuator through a serial control interface.

8. The method for reducing terminal power consumption during low-Earth orbit satellite transit according to any one of claims 1 to 6, characterized in that, When the elevation angle is less than the minimum effective elevation angle, the terminal adjusts the RF front-end output power to the minimum value or enters a low-power standby state; when the elevation angle is not less than the minimum effective elevation angle and not greater than 60°, the terminal dynamically adjusts the transmit power according to the elevation angle-equivalent omnidirectional radiated power optimization mapping table; when the elevation angle is greater than 60°, the terminal reduces the RF front-end output power to the power that meets the demodulation threshold. An elevation hysteresis range is set near the lowest effective elevation angle, and the current power state is maintained within the elevation hysteresis range.

9. The method for reducing terminal power consumption during low-Earth orbit satellite transit according to any one of claims 1 to 6, characterized in that, The terminal classifies the received signal into three states based on the signal-to-noise ratio (SNR): good signal quality, critical signal quality, and poor signal quality. In the good signal quality state, the terminal maintains the current power strategy. In the critical signal quality state, it pauses further reduction of transmission power. In the poor signal quality state, it increases the transmission power in increments according to a preset power step size, and waits a preset time after each increase in transmission power to re-detect the SNR until the SNR meets a preset requirement or the transmission power reaches the maximum equivalent isotropic radiated power.

10. The method for reducing terminal power consumption during low-Earth orbit satellite transit according to claim 3, characterized in that, The terminal determines the beam edge gain attenuation based on the angular deviation between the beam pointing and the actual direction of the target low-orbit satellite, and incorporates the beam edge gain attenuation when determining the minimum equivalent omnidirectional radiation power; when the angular deviation exceeds the allowable range, beam realignment is triggered first; the terminal also records the reliable equivalent omnidirectional radiation power corresponding to the current elevation angle during the power increment process, and updates the elevation angle-equivalent omnidirectional radiation power optimization mapping table using the reliable equivalent omnidirectional radiation power.

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