Sub-band and sub-band power adjustment method for multiple users in DTP satellite multi-beam overlapping coverage area

Abstract

The invention discloses a sub-band and sub-band power adjustment method for multiple users in a DTP satellite multi-beam overlapping coverage area. Reasonable user transmitting sub-band and receiving sub-band measurement periods are respectively set by respectively measuring power attenuation conditions of a user transmitting sub-band and a user receiving sub-band. Furthermore, according to the power attenuation condition of the transmitting sub-band or the receiving sub-band of the user in the measurement period, the user needing to be adjusted and the adjustment priority are determined. For a plurality of beams where the current user to be adjusted is located, a candidate beam set is determined according to whether the residual power of each beam and the number of idle sub-bands meet the total sub-band power of the adjusted user and the number of sub-bands occupied by the user or not, and finally, according to the power-band ratio maximization principle of the residual power of the beams and the idle sub-band set, the candidate beam set is determined. And selecting an optimal adjustment beam for the user from the candidate beam set, and allocating the corresponding sub-band and the power of each sub-band for the user in the optimal adjustment beam, so that the signal bandwidth and power allocation advantages of the DTP satellite by taking the sub-band as the granularity are exerted.

Description

Technical Field

[0001] The invention belongs to the technical field of satellite communications, and in particular relates to a sub-band and sub-band power adjustment method for multiple users in a DTP satellite multi-beam overlapping coverage area. Background Art

[0002] DTP (Digital Transparent Process) satellites are high-throughput satellites that utilize digital transparent processing technology and implement inter-beam articulation at a sub-band granularity. When using a mix of spot and shaped beams for coverage, DTP satellites have areas of overlapping coverage. When communicating in overlapping coverage areas, mobile users (aircraft, ships, vehicles, backpacks, portable devices, etc.) experience signal power fluctuations due to movement, leading to challenges with transmitting and receiving sub-bands and their power adjustment. This fundamental issue lies in how to select and adjust the power of the multiple transmit and receive beams. DTP satellites have only recently been introduced and put into practical use. The current solution is to follow the traditional high-throughput satellite beam switching method, selecting the beam with the highest equivalent isotropically radiated power (EIRP) among multiple beams as the transmit and receive beam. Onboard, the power of the newly selected beam is evenly distributed across each sub-band according to the ratio of the sub-band bandwidth to the beam bandwidth.

[0003] The traditional high-throughput satellite beam switching method has three major drawbacks when applied to the overlapping beam coverage area of ​​DTP satellites:

[0004] (1) Users all select the beam with the largest equivalent isotropic radiation power as the signal receiving and transmitting beam, which will cause the service load of different satellite beams to be unbalanced.

[0005] (2) Beam switching is based on the user's location and there is no signal power measurement. When the signal attenuation is not obvious, some unnecessary switching will occur, affecting the communication quality.

[0006] (3) For different users in the same beam area, the power allocation of the onboard payload is proportional to the user's signal bandwidth. Users with larger signal bandwidth are allocated more power, without considering that different users have different requirements for communication service quality. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for adjusting sub-bands and sub-band powers for multiple users in a DTP satellite multi-beam overlapping coverage area, so as to solve the technical problems in the prior art of adjusting sub-bands and sub-band powers, such as unbalanced bandwidth and power distribution of each beam of the DTP satellite, simple payload power distribution method, and the need to further improve the granularity and adjustment accuracy of signal power adjustment.

[0008] The technical solution adopted by the present invention is a method for adjusting sub-bands and sub-band powers for multiple users in a DTP satellite multi-beam overlapping coverage area, which adjusts the transmission sub-bands and their powers for multiple users, including the following steps:

[0009] S1, based on the acquired user latitude and longitude information, determine M users located in the multi-beam overlapping coverage area;

[0010] S2, adjusting the measurement period of the M user transmit subband powers in sequence according to the measured power attenuation of the M user transmit subbands;

[0011] S3, determining S users for which transmit subbands and subband powers need to be adjusted based on the measured power attenuation of the M user transmit subbands;

[0012] S4, selecting one user from the S users in descending order of transmit sub-band power attenuation values ​​as the user to be adjusted;

[0013] S5, calculating the new power of each transmission sub-band of the user to be adjusted, and obtaining the total power P required for all transmission sub-bands;

[0014] S6, the remaining power of each beam in the beam set of the user to be adjusted is P free , according to P free ≥P, a beam set B is constructed. If the beam set B is an empty set, the transmit subband and subband power of the user to be adjusted are not adjusted, and the process goes to S11.

[0015] S7: Select a beam from beam set B to construct beam set C. The condition for any beam in beam set B to be included in beam set C is that the beam has at least one idle subband cluster with a number of idle subbands ≥ the number of user transmit subbands. If beam set C is empty, the transmit subbands and subband powers of the user to be adjusted are not adjusted, and the process goes to S11.

[0016] S8: Calculate the remaining power of each beam in beam set C and the power-to-band ratio γ of the idle subband set, and select the beam with the largest power-to-band ratio as the new transmit beam for the user to be adjusted.

[0017] S9: Adjust the user's current transmit subband to the idle subband cluster in the new beam whose number of idle subbands is closest to the number of transmit subbands;

[0018] S10, completing transmit subband power adjustment according to the new power of each transmit subband of the user calculated in S5;

[0019] S11, repeat S4 to S10 until S users are traversed and the adjustment of their transmission subbands and subband powers is completed.

[0020] Furthermore, in S2, the specific steps of sequentially adjusting the measurement period of the M user transmit subband powers according to the power attenuation of the M user transmit subbands obtained by measurement include:

[0021] S21, when a user has N transmission subbands, the power attenuation value of the user's transmission subband is defined as the maximum attenuation value of the N transmission subbands measured, denoted as δdB;

[0022] S22, adaptively adjusting the user transmit sub-band power measurement period based on the time required for the transmit sub-band power to attenuate by 1 dB;

[0023] In step S23, if the current measurement period is T and the measured power attenuation is δdB, the adaptively adjusted measurement period is T′, where T′ corresponds to 1dB power attenuation. The relationship among T, δ, and T′ is defined by the following equation:

[0024]

[0025] S24, the measurement period T′ after adaptive adjustment is:

[0026]

[0027] in, Indicates rounding up.

[0028] Furthermore, in S3, the basis for determining the S users who need to adjust the transmission subbands and subband powers is that in the current measurement period, the transmission subband power attenuation values ​​δ of the S users need to satisfy δ≥1dB.

[0029] Furthermore, in S5, the specific steps of calculating the new power of each transmission subband of the user to be adjusted to obtain the total power P required for all transmission subbands include:

[0030] S51: The number of transmit subbands of the user to be adjusted is N, and the subbands are numbered [k+1, k+2, ..., k+N], where k+1 represents the starting subband number of the user's transmit subband in the current transmit beam, and k+N represents the ending subband number.

[0031] S52, the power of each transmission sub-band of the user at the last measurement time t is [P k+1,t , P k+2,t ,…,P k+N,t ], at the current measurement time t+τ, they are [P k+1,t+τ , P k+2,t+τ ,…,P k+N,t+τ ], where τ is the measurement period of the user's transmit sub-band power;

[0032] S53, the new power of each transmitting sub-band is [Pk+1,t+τ +Δ k+1 , P k+2,t+τ +Δ k+2 ,…,P k+N,t+τ +Δ k+N ], where Δ i is the power compensation amount of the transmit subband numbered i;

[0033] S54, the total power P required for all transmit sub-bands is:

[0034]

[0035] For any transmitting subband i∈[k+1,k+N], its subband power compensation amount Δ i =P i,t -P i,t+τ +1dB;

[0036] Among them, Δ i Indicates that when adjusting the power of transmit sub-band i, a 1dB compensation margin is added on top of the compensation based on its power attenuation value.

[0037] Furthermore, in S6, the beam residual power P free It is defined as the total power of the beam minus the total power occupied by the transmit sub-bands of other users in the beam, and the remaining power P of the transmit beam where the user to be adjusted is located. free Including the total power occupied by the user's own transmit sub-band to be adjusted.

[0038] Furthermore, in S8, the residual power P of each beam in the beam set C is calculated. free And the power band ratio γ of the idle subband set:

[0039] γ=P free / F

[0040] Wherein, F is the total bandwidth of the idle subband set.

[0041] Furthermore, for multi-user receiving sub-bands and their power adjustment, the same steps as those for transmitting sub-bands and their power adjustment are adopted.

[0042] The beneficial effects of the present invention are:

[0043] (1) The present invention adjusts the user's receiving and transmitting sub-band power based on sub-band power measurement. The sub-band power measurement period is based on the time required for the sub-band power to attenuate by 1 dB, and adaptive adjustment is performed on the receiving and transmitting sub-band power measurement period to ensure that the adjustment time is more reasonable.

[0044] (2) When the present invention adjusts the power of the user's transceiver subband, it adjusts the power based on the power attenuation of each subband at the current measurement moment and the previous measurement moment, plus a 1dB margin. This ensures the accuracy of the power adjustment of each transceiver subband. The addition of 1dB of power margin ensures that within a power measurement cycle, when the power attenuation is large, the transceiver signal still has sufficient power to maintain signal quality.

[0045] (3) The present invention selects the beams of the transmitting and receiving sub-bands based on the principle of maximizing the power-band ratio of the beam's residual power to the idle sub-band set, that is, maximizing the power that the payload can provide per unit bandwidth. By comprehensively considering the bandwidth and power factors of the beam, the bandwidth and power of the DTP satellite can be better balanced among the beams, preventing user services from being excessively concentrated in beams with high equivalent isotropic radiation power.

[0046] (4) The present invention allows users to use different beams to send and receive signals respectively, so that the DTP satellite can achieve more flexible on-board hinge configuration and sub-band power adjustment for each user service with sub-band as the granularity. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a flow chart of the overall steps of multi-user transmission sub-band and power adjustment of the present invention;

[0048] Figure 2 Schematic diagram of the six beam coverage areas and overlapping coverage areas of the DTP satellite of the present invention;

[0049] Figure 3 Schematic diagram of user transmission sub-band distribution and sub-band power at measurement time t+τ of the present invention;

[0050] Figure 4 A schematic diagram of new user transmission sub-band power that needs to be adjusted for the present invention;

[0051] Figure 5 This is a flow chart of the overall steps of multi-user receiving sub-bands and power adjustment according to the present invention. DETAILED DESCRIPTION

[0052] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings.

[0053] Compared with traditional high-throughput satellites, DTP satellites are equipped with a dedicated DTP payload ground control station, which dynamically measures and controls the hinge relationship between the input and output sub-bands in the payload and the power of each sub-band. This provides an engineering implementation basis for sub-band and sub-band power adjustment based on signal power measurement.

[0054] A method for adjusting the sub-band and sub-band power of multiple users in a DTP satellite multi-beam overlapping coverage area is provided. The method adjusts the user sub-band and sub-band power according to the transmit and receive sub-bands of multiple satellite communication users in the DTP satellite multi-beam overlapping coverage area and their power attenuation, based on the principle of maintaining a balanced power-band ratio by the remaining power of each beam and the idle sub-bands. Figure 1 As shown, for multi-user transmission subbands and their power adjustment, the following steps are included:

[0055] S1. Determine M users located in the multi-beam overlapping coverage area based on the acquired user latitude and longitude information.

[0056] like Figure 2 As shown in the figure, a DTP satellite has six beams in a given area. Beams i, i+2, and i+4 are typical high-throughput satellite spot beams, while beams i+1, i+3, and i+5 are shaped beams. Each beam has a total bandwidth of 500 MHz and is divided into 400 subbands, each with a bandwidth of 1.25 MHz. The six beams overlap, and for the M users within the overlapping coverage area, beams i through i+5 can all be used for signal transmission and reception.

[0057] S2, according to the power attenuation of the M user transmission subbands obtained by measurement, sequentially adjust the measurement period of the M user transmission subband powers, the specific steps include:

[0058] S21, when a user has N (N≥1) transmission subbands, the power attenuation value of the user's transmission subband is defined as the maximum attenuation value of the N transmission subbands obtained by measurement, denoted as δdB.

[0059] S22, the transmit subband power measurement period is crucial for timely adjustment of the transmit subband and subband power. To prevent these two extreme situations, such as the measurement period being too long resulting in a large power attenuation value of the user transmit subband, or the user transmit subband power attenuation value being actually very small but frequent measurements are required, the user transmit subband power measurement period is adaptively adjusted based on the time required for the transmit subband power to attenuate by 1dB.

[0060] In step S23, if the current measurement period is T and the measured power attenuation is δdB, the adaptively adjusted measurement period is T′, where T′ corresponds to 1dB power attenuation. The relationship among T, δ, and T′ is defined by the following equation:

[0061]

[0062] S24, so the measurement period T′ after adaptive adjustment is:

[0063]

[0064] in, Indicates rounding up.

[0065] S3. Determine S (S≤M) users whose transmit subbands and subband powers need to be adjusted based on the measured power attenuation of the M user transmit subbands.

[0066] The basis for determining the S users who need to adjust the transmit subband and subband power is that in the current measurement period, the transmit subband power attenuation values ​​δ of the S users need to satisfy δ≥1dB.

[0067] S4: Select one user from the S users in descending order according to the transmit sub-band power attenuation values ​​as the user to be adjusted.

[0068] S5, calculate the new power of each transmission subband of the user to be adjusted to obtain the total power P required for all transmission subbands. The specific steps include:

[0069] S51, the number of transmit subbands of the current user to be adjusted is N, N ≥ 1, and the subbands are numbered [k+1, k+2, ..., k+N] in sequence, where k+1 represents the starting subband number of the user's transmit subband in the current transmit beam, and k+N represents the ending subband number.

[0070] S52, the power of each transmission sub-band of the user at the last measurement time t is [P k+1,t , P k+2,t ,…,P k+N,t ],like Figure 3 As shown, at the current measurement time t+τ, they are [P k+1,t+τ , P k+2,t+τ ,…,P k+N,t+τ ], where τ is the measurement period of the user's transmit sub-band power.

[0071] S53, such as Figure 4 As shown, the new power of each transmitting sub-band is [P k+1,t+τ +Δ k+1 , P k+2,t+τ +Δ k+2 ,…,P k+N,t+τ +Δ k+N ], where Δ i is the power compensation amount of the transmit subband numbered i.

[0072] S54, the total power P required for all transmit sub-bands is:

[0073]

[0074] For any transmitting subband i∈[k+1,k+N], its subband power compensation amount Δ i =P i,t -P i,t+τ +1dB.

[0075] Among them, Δ i Indicates that when adjusting the power of transmit sub-band i, a 1dB compensation margin is added on top of the compensation based on its power attenuation value.

[0076] S6, the remaining power of each beam in the beam set of the user to be adjusted is P free , according to P free ≥P, a beam set B is constructed. If the beam set B is an empty set, the transmit subband and subband power of the user to be adjusted are not adjusted, and the process goes to S11.

[0077] Beam residual power P free It is defined as the total power of the beam minus the total power occupied by the transmit sub-bands of other users in the beam. Therefore, the remaining power P of the transmit beam where the user to be adjusted is free Including the total power occupied by the user's own transmit sub-band to be adjusted.

[0078] S7: Select a beam from beam set B to construct beam set C. Any beam in beam set B can be added to beam set C only if the beam has at least one idle subband cluster with a number of idle subbands ≥ the number of user transmit subbands. If beam set C is empty, the transmit subbands and subband powers of the user to be adjusted are not adjusted, and the process proceeds to S11.

[0079] S8, calculate the residual power P of each beam in beam set C free and the power-band ratio γ of the idle subband set, and select the beam with the largest power-band ratio as the new transmission beam of the user to be adjusted.

[0080] The total bandwidth of the idle subband set is F Hz, and the power-band ratio is γ:

[0081] γ=P free / F Formula 4.

[0082] S9: Adjust the user's current transmit subband to an idle subband cluster in the new beam whose number of idle subbands is closest to the number of transmit subbands.

[0083] S10 , completing transmission subband power adjustment according to the new power of each transmission subband of the user calculated in S5 .

[0084] S11, repeat S4 to S10 until S users are traversed and the adjustment of their transmission subbands and subband powers is completed.

[0085] For multi-user receiving sub-band and its power adjustment, the same steps as the transmitting sub-band and its power adjustment are adopted, such as Figure 5 shown.

[0086] It is important to note that:

[0087] (1) For the same user, the number of transmitting sub-bands and receiving sub-bands are different due to the different bandwidths of the signals being transmitted and received. The power attenuation value of the receiving sub-band of the user is the maximum value of the attenuation values ​​of all the receiving sub-bands obtained by measurement.

[0088] (2) For the same user, the transmit sub-band power attenuation value and the receive sub-band power attenuation value are different, so the transmit sub-band power measurement period and the receive sub-band power measurement period are also different, but the calculation method for the two is the same.

[0089] (3) For the same user, when its transmit subband and subband power are adjusted, its receive subband and subband power do not necessarily need to be adjusted, and vice versa.

[0090] In summary, the present invention proposes a method for adjusting sub-band and sub-band power for multiple users in a DTP satellite multi-beam overlapping coverage area. By measuring the power attenuation of the user's transmit sub-band and receive sub-band, reasonable user transmit sub-band and receive sub-band measurement periods are set. Furthermore, based on the power attenuation of the user's transmit sub-band or receive sub-band within the measurement period, the user to be adjusted and the adjustment priority are determined. For the multiple beams where the user to be adjusted is currently located, the candidate beam set is determined based on whether the remaining power and number of idle sub-bands of each beam meet the total sub-band power of the user after adjustment and the number of sub-bands occupied by the user. Finally, based on the principle of maximizing the power-to-band ratio of the beam's remaining power to the idle sub-band set, the optimal adjustment beam is selected for the user from the candidate beam set. The corresponding sub-band and each sub-band power are allocated to the user in the optimal adjustment beam, thereby leveraging the DTP satellite's signal bandwidth and power allocation advantages based on sub-band granularity.

[0091] Parts of the present invention that are not described in detail belong to common knowledge among those skilled in the art.

Claims

1. A method for adjusting sub-bands and sub-band powers for multiple users in a DTP satellite multi-beam overlapping coverage area, characterized in that: The multi-user transmission subband and power adjustment includes the following steps: S1, based on the acquired user latitude and longitude information, determine M users located in the multi-beam overlapping coverage area; S2, adjusting the measurement period of the M user transmit subband powers in sequence according to the measured power attenuation of the M user transmit subbands; S3, determining S users for which transmit subbands and subband powers need to be adjusted based on the measured power attenuation of the M user transmit subbands; S4, selecting one user from the S users in descending order of transmit sub-band power attenuation values ​​as the user to be adjusted; S5, calculating the new power of each transmission sub-band of the user to be adjusted, and obtaining the total power P required for all transmission sub-bands; S6, the remaining power of each beam in the beam set of the user to be adjusted is P free , according to P free ≥P, a beam set B is constructed. If the beam set B is an empty set, the transmit subband and subband power of the user to be adjusted are not adjusted, and the process goes to S11. S7: Select a beam from beam set B to construct beam set C. The condition for any beam in beam set B to be included in beam set C is that the beam has at least one idle subband cluster with a number of idle subbands ≥ the number of user transmit subbands. If beam set C is empty, the transmit subbands and subband powers of the user to be adjusted are not adjusted, and the process goes to S11. S8: Calculate the remaining power of each beam in beam set C and the power-to-band ratio γ of the idle subband set, and select the beam with the largest power-to-band ratio as the new transmit beam for the user to be adjusted. S9: Adjust the user's current transmit subband to the idle subband cluster in the new beam whose number of idle subbands is closest to the number of transmit subbands; S10, completing transmit subband power adjustment according to the new power of each transmit subband of the user calculated in S5; S11, repeat S4 to S10 until S users are traversed and the adjustment of their transmission subbands and subband powers is completed.

2. The method for adjusting sub-bands and sub-band powers for multiple users in a DTP satellite multi-beam overlapping coverage area according to claim 1, characterized in that: In S2, the specific steps of sequentially adjusting the measurement period of the M user transmit subband powers according to the power attenuation of the M user transmit subbands obtained by measurement include: S21, when a user has N transmission subbands, the power attenuation value of the user's transmission subband is defined as the maximum attenuation value of the N transmission subbands measured, denoted as δdB; S22, adaptively adjusting the user transmit sub-band power measurement period based on the time required for the transmit sub-band power to attenuate by 1 dB; In step S23, if the current measurement period is T and the measured power attenuation is δdB, the adaptively adjusted measurement period is T′, where T′ corresponds to 1dB power attenuation. The relationship among T, δ, and T′ is defined by the following equation: S24, the measurement period T′ after adaptive adjustment is: in, Indicates rounding up.

3. The method for adjusting sub-bands and sub-band powers for multiple users in a DTP satellite multi-beam overlapping coverage area according to claim 2, characterized in that: In S3, the basis for determining the S users who need to adjust the transmission subband and subband power is that in the current measurement period, the transmission subband power attenuation values ​​δ of the S users need to satisfy δ≥1dB.

4. The method for adjusting sub-bands and sub-band powers for multiple users in a DTP satellite multi-beam overlapping coverage area according to claim 1, characterized in that: In S5, the specific steps of calculating the new power of each transmission subband of the user to be adjusted to obtain the total power P required for all transmission subbands include: S51: The number of transmit subbands of the user to be adjusted is N, and the subbands are numbered [k+1, k+2, ..., k+N], where k+1 represents the starting subband number of the user's transmit subband in the current transmit beam, and k+N represents the ending subband number. S52, the power of each transmission sub-band of the user at the last measurement time t is [P k+1,t , P k+2,t ,…,P k+N,t ], at the current measurement time t+τ, they are [P k+1,t+τ , P k+2,t+τ ,…,P k+N,t+τ ], where τ is the measurement period of the user's transmit sub-band power; S53, the new power of each transmitting sub-band is [P k+1,t+τ +Δ k+1 , P k+2,t+τ +Δ k+2 ,…,P k+N,t+τ +Δ k+N ], where Δ i is the power compensation amount of the transmit subband numbered i; S54, the total power P required for all transmit sub-bands is: For any transmitting subband i∈[k+1,k+N], its subband power compensation amount Δ i =P i,t -P i,t+τ +1dB; Among them, Δ i Indicates that when adjusting the power of transmit sub-band i, a 1dB compensation margin is added on top of the compensation based on its power attenuation value.

5. The method for adjusting sub-bands and sub-band powers for multiple users in a DTP satellite multi-beam overlapping coverage area according to claim 1, characterized in that: In S6, the beam residual power P free It is defined as the total power of the beam minus the total power occupied by the transmit sub-bands of other users in the beam, and the remaining power P of the transmit beam where the user to be adjusted is located. free Including the total power occupied by the user's own transmit sub-band to be adjusted.

6. The method for adjusting sub-bands and sub-band powers for multiple users in a DTP satellite multi-beam overlapping coverage area according to claim 1, characterized in that: In S8, the residual power P of each beam in the beam set C is calculated. free And the power band ratio γ of the idle subband set: γ=P free / F Wherein, F is the total bandwidth of the idle subband set.

7. The method for adjusting sub-bands and sub-band powers for multiple users in a DTP satellite multi-beam overlapping coverage area according to claim 1, characterized in that: For multi-user receiving sub-bands and their power adjustment, the same steps as those for transmitting sub-bands and their power adjustment are adopted.

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