CN111182594A - Low-orbit satellite constellation system cell switching method and device based on ephemeris information - Google Patents

Low-orbit satellite constellation system cell switching method and device based on ephemeris information Download PDF

Info

Publication number
CN111182594A
CN111182594A CN201911275733.5A CN201911275733A CN111182594A CN 111182594 A CN111182594 A CN 111182594A CN 201911275733 A CN201911275733 A CN 201911275733A CN 111182594 A CN111182594 A CN 111182594A
Authority
CN
China
Prior art keywords
satellite
mobile terminal
cell
switching
current
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201911275733.5A
Other languages
Chinese (zh)
Other versions
CN111182594B (en
Inventor
田洲
刘岩
惠蕾放
孙汉汶
赵雨
毛一丁
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xian Institute of Space Radio Technology
Original Assignee
Xian Institute of Space Radio Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Xian Institute of Space Radio Technology filed Critical Xian Institute of Space Radio Technology
Priority to CN201911275733.5A priority Critical patent/CN111182594B/en
Publication of CN111182594A publication Critical patent/CN111182594A/en
Application granted granted Critical
Publication of CN111182594B publication Critical patent/CN111182594B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
    • H04W36/00835—Determination of neighbour cell lists
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
    • H04W36/00837—Determination of triggering parameters for hand-off
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
    • H04W36/0085—Hand-off measurements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/24—Reselection being triggered by specific parameters
    • H04W36/30—Reselection being triggered by specific parameters by measured or perceived connection quality data
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/18521—Systems of inter linked satellites, i.e. inter satellite service

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Radio Relay Systems (AREA)

Abstract

The invention discloses a cell switching method and device of a low-orbit satellite constellation system based on ephemeris information. The mobile terminal calculates the visible time of each wave beam in the neighbor cell list, screens out the wave beams with the visible time smaller than the wave beam visible time threshold, selects the wave beam with the maximum switching weight value in the screened neighbor cell list as a target wave beam, and finally sends a request for switching to the target wave beam to a source wave beam. The method has the characteristics of improving the beam cell switching reliability, reducing the ping-pong switching probability, reducing the number of system control signaling and improving the network efficiency.

Description

Low-orbit satellite constellation system cell switching method and device based on ephemeris information
Technical Field
The invention discloses a cell switching method and device of a low-orbit satellite constellation system based on ephemeris information, and belongs to the field of mobility management in a mobile communication system.
Background
The low-earth-orbit satellite communication system has the characteristics of low time delay, high bandwidth utilization rate, low power consumption of the mobile terminal and the like, and is one of the development directions of future mobile communication technologies. Meanwhile, because the LEO system satellite orbit is low, the satellite moves at a high speed relative to the earth, so that communication connection is frequently switched between satellites or among beams, the overhead of system control signaling is greatly increased, and the call drop rate and the call termination probability are obviously improved. Therefore, mobility management technology is a focus and focus of research on low earth orbit satellite communication systems.
Currently, the research on the handover technology of the low earth orbit satellite communication system mainly includes the research on the network layer handover and the research on the link layer handover. The research of network layer handover mainly uses Mobile IP (MIP) technology to manage the Mobile terminal IP, and the research of link layer handover mainly discusses the influence of different handover criteria on the Mobile terminal drop call rate, call blocking rate, network utilization rate and other indexes. Link layer handovers may be classified as inter-satellite handovers and inter-beam handovers according to the handover beam and source beam satellite affiliation. Inter-satellite handover refers to a handover of a mobile terminal from a satellite coverage area to the coverage area of another satellite, and inter-beam handover refers to a handover of a mobile terminal between different beams of the same satellite. For low earth orbit satellite communication systems, the frequency of inter-beam handovers requires that the design of handover guidelines be heavily considered to avoid the occurrence of "ping-pong handovers".
Currently, common criteria for link layer handoff in low earth orbit satellite communication systems include the strongest signal criterion, the longest visible time criterion, the maximum elevation angle criterion, and the minimum load criterion. The study of these criteria is usually based on ideal cellular beams, taking into account less of the requirements of the actual system and the feasibility of the implementation. Therefore, the invention provides a cell switching method and a device of a low-orbit satellite constellation system based on ephemeris information.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the invention provides a switching method and a device thereof based on ephemeris track prediction aiming at the switching criterion of a low-orbit satellite communication system, which are used for predicting received broadcast ephemeris information, calculating a neighbor cell list at the switching triggering moment by combining the geographical position information of a mobile terminal, and screening an optimal access beam from the neighbor cell list according to the visible time of the beam and the received signal strength, thereby reducing the switching frequency of the mobile terminal, reducing the occurrence probability of ping-pong switching and improving the overall network utilization rate of the system.
The technical solution of the invention is as follows: the technical scheme adopted by the invention is as follows: a cell switching method of a low-orbit satellite constellation system based on ephemeris information comprises the following steps:
(1) the mobile terminal receives the signal of the current service cell at the current time t, and judges whether the received signal intensity of the current service cell is smaller than the signal intensity measurement threshold value P of any adjacent service cellthresh1If yes, continuing to execute the step (2); otherwise, the current serving cell does not need to be switched;
(2) the mobile terminal receives broadcast ephemeris information at the moment t, determines the position of the satellite-borne point at the moment t according to the position of the service satellite at the moment t in the broadcast ephemeris information at the moment t, and calculates the distance d from the mobile terminal to the satellite-borne point of the service satellite according to the position of the satellite-borne point at the moment tTH(t)；
(3) The mobile terminal is used for receiving the service satellite down-satellite distance d according to the mobile terminalTH(t) calculating the subsatellite half field angle of the serving satellite
Figure BDA0002315510490000021
And a movement direction declination angle mu (t) according to the half-aperture angle of the satellite under the satellite serving
Figure BDA0002315510490000022
And the direction of movement is deviatedAngle mu (t), calculating ideal received signal power sideal(t); judgment sideal(t) whether the value is less than or equal to the set ideal communication threshold value, if so, continuing to execute the step (4), otherwise, adding a value after the interval delta t is increased at the moment t to the t, replacing the t in the step (2) and returning to the step (2);
(4) the mobile terminal calculates critical power of all beams in a coverage satellite set of the mobile terminal according to the satellite position at the moment t, and the critical power is compared with the ideal received signal power s in the step (3)ideal(t) comparing, if the comparison result is larger than or equal to the threshold power, putting the wave beam corresponding to the threshold power into a neighbor list of the mobile terminal, otherwise, discarding the wave beam corresponding to the threshold power;
(5) the mobile terminal simultaneously measures the signal intensity of the current service cell and the signal intensity of the wave beam in the neighbor cell list, and judges whether the received signal intensity of the current service cell is smaller than the set switching trigger threshold value Pthresh2If the current cell number is less than the preset value, continuing to execute the step (6), otherwise, the current serving cell does not need to be switched;
(6) calculating the visible time of the wave beams of the mobile terminal corresponding to the wave beams in the neighbor cell list one by one;
(7) mobile terminal screens out less-than-set wave beam visible time threshold t in neighbor listthreshIf the filtered neighbor list is empty, the set visible time threshold t of the wave beam is setthreshThe size of the neighbor list is reduced by half, and the original neighbor list is screened again until the neighbor list is not empty;
(8) and calculating the beam switching weight values of all the beams in the filtered neighbor cell list, selecting the beam with the maximum beam switching weight value in the neighbor cell list as a target beam, and switching the current beam to the target beam.
Preferably, in step (1), the received signal strength P of the serving cellmeasThe formula for calculation of (t) is:
Figure BDA0002315510490000031
where N is the length of the sampling window,Δ t is the interval of measurement, αnThe weight values of the received power at different sampling moments are shown, and P (t-n delta t) represents the actual received power at the t-n delta t moment;
preferably, the position of the point under the star(s)j,sw) The calculation formula of (2) is as follows:
Figure BDA0002315510490000032
wherein (x)r,yr,zr) The coordinate of the low earth orbit satellite in the geocentric inertial coordinate system, when GAST represents the Greenwich mean star at the current moment, the GAST is equal to the GMST of the Greenwich mean star in value, and the calculation formula of the GMST is as follows:
Figure BDA0002315510490000033
wherein, the parameter C4、C5The values of (1) are respectively the number of seconds contained in one solar day and the conversion coefficient of the solar day and the sidereal day, and the calculation formula of the parameter UT is as follows:
UT mod (JD +0.5,1) [ equation 4]
The JD represents the julian day corresponding to the current day, and the calculation formula is as follows:
Figure BDA0002315510490000041
wherein the parameter Y, M, D represents the year, month and date corresponding to the current day,
Figure BDA0002315510490000046
GMST0representing Greenwich mean time of 0 o' clock in world time, the calculation formula is:
GMST0＝C0+C1T+C2T2-C3T3[ equation 6)]
Wherein, the parameter C0、C1、C2And C3Are 24110.54841, 8640184.812866, 0.0 respectively93104 and 6.2 x 10-6，T＝(JD-2451545.0-UT)/36525.0。
Preferably, the calculation formula of the terminal-substellar point distance is as follows:
Figure BDA0002315510490000042
wherein (u)j,uw) Indicating the current location of the mobile terminal,(s)j,sw) Representing the current position of the sub-satellite point, RERepresenting the radius of the earth.
The calculation formula of the half aperture angle under the satellite is as follows:
Figure BDA0002315510490000043
wherein d isTH(t) represents the terminal-to-subsatellite point distance at time t, RERepresenting the earth radius and h the orbit height.
The calculation formula of the deflection angle of the motion direction is as follows:
Figure BDA0002315510490000044
wherein R isERepresenting the radius of the earth, parameter dTQ(t) the calculation formula is:
Figure BDA0002315510490000045
parameter dHQ(t) the calculation formula is:
Figure BDA0002315510490000051
preferably, the calculation formula of the ideal received signal power is:
sideal(t)＝10logδ2-Lr(t) [ equation 12]
Wherein δ represents a signal field value at time t, and the calculation formula is as follows:
δ ═ H (u, v) [ equation 13]
Wherein the content of the first and second substances,
Figure BDA0002315510490000056
and δ H (u, v) represents a UV coordinate system coordinate-field value mapping relationship of the on-satellite antenna corresponding to the mobile terminal. L isr(t) is the relative path loss of the signal, and the calculation formula is as follows:
Figure BDA0002315510490000052
wherein R isERepresenting the radius of the earth, h representing the orbit height,
Figure BDA0002315510490000053
representing the inferior star half opening angle at time t.
The conditions under which the beam is visible are:
sideal(t)>sthresh[ equation 15)]
Wherein s isthreshThe calculation formula represents the visible critical power value of the beam and is as follows:
sthresh＝sguarantee+soff[ equation 16]
Wherein s isguaranteeThe minimum relative received power for the mobile terminal communication is guaranteed and is determined by the link budget. soffThe value of the intensity drop of the mobile terminal due to signal fading is represented by the following formula:
Figure BDA0002315510490000054
wherein, Pideal(thandover) Representing the moment of handover trigger thandoverIdeal received power of Pmeas(thandover) Representing the actual measured signal strength value at the moment of handover trigger.
Preferably, the beam visibility time calculation formula is:
Figure BDA0002315510490000055
wherein, thandoverFor the handover trigger time, t is the time at which the beam visibility condition is first not satisfied, and Δ t is the calculation interval.
Preferably, the screening criteria of the best access cell beam [ i ] [ j ] are as follows:
beam[i][j]＝argmax{W[i][j]}
s.t.tvisble[i][j]≥tthresh[ equation 19]
Wherein, W [ i ] [ j ] represents the beam switching weight of the i number satellite j number beam in the neighbor list, and the calculation formula is as follows:
Figure BDA0002315510490000061
wherein, Pmeas(thandover)[i][j]And the measured signal strength represents the switching triggering moment of the j wave beam of the i satellite in the adjacent area list, M is a constant for judging whether the wave beam and the source wave beam are under the same satellite, the value under the same satellite is 1, and M is 0 under the condition that the visible time is the same if certain wave beam power values of the j satellite and the i satellite exist under different satellites, so that the probability of switching between the satellites is reduced, and the wave beam switching under the same satellite is ensured to be preferentially selected when the maximum value is calculated. t is tvisble[i][j]Representing the visible time of the mobile terminal to the j wave beam of the i-number satellite in the adjacent area list, T representing the maximum value of the visible time of the wave beam in all the adjacent area wave beams, P representing the maximum value of the intensity of the received signal at the switching triggering moment in all the adjacent area wave beams, and TthreshRepresenting the beam visibility time threshold.
As shown in fig. 2, preferably, the device for switching a cell of a low-earth satellite constellation system based on ephemeris information according to the present invention includes:
the signal measurement module is used for measuring the signal intensity of the service cell on a service channel and the signal intensity of a pilot signal of an adjacent cell;
the ephemeris information receiving module is used for receiving ephemeris information broadcasted by the satellite-borne base station in a downlink manner;
the mobile terminal positioning module is used for acquiring real-time position information of the mobile terminal;
the ephemeris prediction and satellite node calculation module is used for predicting ephemeris information at the current moment according to the received latest ephemeris information and calculating the satellite node position of the low-orbit constellation;
the signal field value storage module is used for pre-storing the coordinates and the signal field value pairs under the UV coordinate system of each beam internal branch point according to the antenna design condition;
the neighbor cell list calculation module is used for calculating and storing a neighbor cell list of the mobile terminal at the switching triggering moment according to the satellite point information, the mobile terminal position information and the signal field value;
the beam visible time calculation module is used for switching the trigger time and calculating the beam visible time of all beam cells in the neighbor cell list according to the satellite point information, the mobile terminal position information and the signal field value;
and the screening and judging module screens out the best access beam cell for the beam cell in the neighbor cell list according to the visible time of the beam and the intensity of the received signal.
Compared with the prior art, the invention has the beneficial effects that:
(1) the invention provides a method and a device for switching cells of a low-orbit satellite constellation system based on ephemeris information. This handover criterion reduces the frequency of mobile terminal handovers starting from the requirements of practical low earth orbit satellite systems.
(2) The method is simultaneously suitable for inter-satellite switching and intra-satellite switching, and has strong operability;
(3) the invention judges from two dimensions of power and time at the same time, the optimized switching target is real, and the reliability is high
(4) The invention effectively reduces the control signaling overhead brought by switching between the satellites.
Drawings
FIG. 1 is a process flow diagram of the present process;
FIG. 2 is a schematic diagram of a possible apparatus provided by the present method;
fig. 3 is a flow chart of possible intra-satellite beam switching signaling transmission provided by the present method;
fig. 4 is a flow chart of a possible inter-satellite beam switching signaling transmission provided by the present method;
fig. 5 is an application scenario diagram of the method.
Detailed Description
The present invention is further described with reference to the accompanying drawings and specific examples, which are intended to be illustrative only and not to be limiting of the scope of the invention, and various equivalent modifications of the invention will occur to those skilled in the art upon reading the present invention and fall within the scope of the invention defined by the appended claims.
The invention discloses a cell switching method and device of a low-orbit satellite constellation system based on ephemeris information. The mobile terminal judges the switching triggering time according to the signal intensity of the received service satellite, then predicts the position of the satellite points under the low orbit satellite according to the received satellite ephemeris parameters, calculates the covering satellite set of the switching triggering time according to the predicted position of the satellite points under the low orbit satellite, and compares the mobile terminal with the wave beam characteristic point set of all wave beams of each satellite in the covering satellite set to obtain a neighbor cell list. The mobile terminal calculates the visible time of each wave beam in the neighbor cell list, screens out the wave beams with the visible time smaller than the wave beam visible time threshold, selects the wave beam with the maximum switching weight value in the screened neighbor cell list as a target wave beam, and finally sends a request for switching to the target wave beam to a source wave beam. The method has the characteristics of improving the beam cell switching reliability, reducing the ping-pong switching probability, reducing the number of system control signaling and improving the network efficiency.
As shown in fig. 1, a method for switching a cell of a low-earth-orbit satellite constellation system based on ephemeris information according to the present invention includes the following steps:
(1) the mobile terminal receives the signal of the current service cell at the current time t and judges the received current service cellWhether the signal strength of a cell is less than the signal strength measurement threshold P of any one of the neighboring serving cellsthresh1If yes, continuing to execute the step (2); otherwise, the current serving cell does not need to be switched;
(2) the mobile terminal receives broadcast ephemeris information at the moment t, determines the position of the satellite-borne point at the moment t according to the position of the service satellite at the moment t in the broadcast ephemeris information at the moment t, and calculates the distance d from the mobile terminal to the satellite-borne point of the service satellite according to the position of the satellite-borne point at the moment tTH(t)；
(3) The mobile terminal is used for receiving the service satellite down-satellite distance d according to the mobile terminalTH(t) calculating the subsatellite half field angle of the serving satellite
Figure BDA0002315510490000081
And a movement direction declination angle mu (t) according to the half-aperture angle of the satellite under the satellite serving
Figure BDA0002315510490000082
And a motion direction deviation angle mu (t) for calculating the ideal received signal power sideal(t); judgment sideal(t) whether the value is less than or equal to the set ideal communication threshold value, if so, continuing to execute the step (4), otherwise, adding a value after the interval delta t is increased at the moment t to the t, replacing the t in the step (2) and returning to the step (2);
(4) the mobile terminal calculates critical power of all beams in a coverage satellite set of the mobile terminal according to the satellite position at the moment t, and the critical power is compared with the ideal received signal power s in the step (3)ideal(t) comparing, if the comparison result is larger than or equal to the threshold power, putting the wave beam corresponding to the threshold power into a neighbor list of the mobile terminal, otherwise, discarding the wave beam corresponding to the threshold power;
(5) the mobile terminal simultaneously measures the signal intensity of the current service cell and the signal intensity of the wave beam in the neighbor cell list, and judges whether the received signal intensity of the current service cell is smaller than the set switching trigger threshold value Pthresh2If the current cell number is less than the preset value, continuing to execute the step (6), otherwise, the current serving cell does not need to be switched;
(6) calculating the visible time of the wave beams of the mobile terminal corresponding to the wave beams in the neighbor cell list one by one;
(7) mobile terminal screens out less-than-set wave beam visible time threshold t in neighbor listthreshIf the filtered neighbor list is empty, the set visible time threshold t of the wave beam is setthreshThe size of the neighbor list is reduced by half, and the original neighbor list is screened again until the neighbor list is not empty;
(8) and calculating the beam switching weight values of all the beams in the filtered neighbor cell list, selecting the beam with the maximum beam switching weight value in the neighbor cell list as a target beam, and switching the current beam to the target beam.
Mobile terminal, in particular satellite terminal
Neighbor measurement threshold Pthresh1The method includes that the mobile terminal starts signal intensity measured by a neighboring cell, and the neighboring cell is determined according to system requirements;
broadcast ephemeris information, including: the longitude and latitude position of the service satellite at the current time t also comprises information of the satellite such as time, running speed, running azimuth, satellite number, beam number and the like.
The set ideal communication threshold value is the minimum relative receiving power value for guaranteeing the communication of the mobile terminal and is determined according to the link budget.
The coverage satellite set refers to a set of satellites that the mobile terminal can receive signals at time t.
Set handover trigger threshold Pthresh2The power determination value when switching is required is determined by the transmission power (antenna design value) of the current access beam, the transmission loss of the distance power of the satellite point (path power loss of the position of the satellite point) and the minimum receiving power (mobile terminal design value) of the mobile terminal.
The mobile terminal beam visible time corresponding to each beam is the time when the mobile terminal can measure the signal corresponding to each beam.
The set beam visible time threshold tthreshThe size of the neighbor list is reduced by half, and the original neighbor list is screened again until the neighbor list is not empty; when the list screened out under the visible time threshold of the wave beam is empty, the value of the time is reduced to halfAnd resetting this value as the beam visibility time threshold
The beam switching weight value is a value for judging the switching target beam, and the value is the maximum value of the sum of constants of the visible time of each beam covering the mobile terminal, the measurement power of each beam covering the mobile terminal at the switching moment and whether each beam covering the mobile terminal and the current access beam are in the same star.
And the current beam is switched to the target beam, so that cell switching is realized.
The critical power of all beams in the set of coverage satellites of the mobile terminal refers to the received power of the mobile terminal, and the value is determined according to the transmitting power of the satellite antenna.
Fig. 5 is a schematic view of an application scenario of the switching method based on ephemeris trajectory prediction in the low earth orbit satellite communication system according to the preferred embodiment of the present invention. The low-orbit constellation adopted in the embodiment totally comprises 6 orbits, the longitude difference of the orbit ascending point is fixed, 10 satellites are uniformly distributed in each orbit, the specific parameters of the system are shown in the following table 1, and the specific values and the constant values are shown in the following table 2, wherein the specific values of the thresholds can be properly adjusted according to the simulation result and the system requirement, the processes of inter-satellite switching and intra-satellite beam switching are illustrated in fig. 3 and 4, the switching method disclosed by the invention is suitable for two situations, and the satellite ephemeris information contains the information whether the current beam and the measurement beam are in the same satellite.
TABLE 1 System parameter Table
Figure BDA0002315510490000101
TABLE 2 threshold and constant tables
Figure BDA0002315510490000112
The invention discloses a further preferable scheme of a low-orbit satellite constellation system cell switching method based on ephemeris information, which comprises the following steps: :
the first step is as follows: and the mobile terminal receives the signal of the current service cell and judges whether the signal intensity of the service cell is smaller than the neighbor cell measurement threshold value.
In this step, the mobile terminal receives the serving cell signal on the traffic channel, and continuously receives N subframes, preferably according to the following formula:
Figure BDA0002315510490000113
obtaining the received signal strength value P of the current time tmeas(t), where P (t-n Δ t) is the power of the subframe received at time t-n Δ t, αnIs the power weight. After the next time slot arrives, the power of the sub-frame received by the first N-1 time slots and the power of the sub-frame received by the current time slot are weighted and averaged to obtain the received signal strength P at the momentmeas(t + Δ t), and so on. When:
Pmeas(t)≤Pthresh1
meanwhile, the mobile terminal starts the neighbor measurement, as shown in fig. 3 and 4. Wherein, Pthresh1The threshold value is the neighbor cell measurement threshold value, is the critical serving cell signal strength for the mobile terminal to start neighbor cell measurement, and is determined according to the system requirements.
The second step is that: and the mobile terminal calculates the distance between the terminal and the sub-satellite point. Firstly, receiving broadcast ephemeris information on a control channel, and obtaining the coordinate (x) of the service satellite at the current moment under the geocentric inertial coordinate system through orbit extrapolationr,yr,zr). Preferably according to the following formula:
Figure BDA0002315510490000121
Figure BDA0002315510490000122
UT mod (JD +0.5,1) [ equation 4]
Figure BDA0002315510490000123
Figure BDA0002315510490000124
Calculating to obtain the coordinate(s) of the satellite point of the service satellitej,sw). Wherein, C0、C1、C2、C3And C4Respectively being a parameter, GMST0Representing Greenwich mean time constant at world time 0, GMST representing Greenwich mean time constant at the current time, numerically equal to Greenwich mean time GAST, JD representing the Confucian day for that day, Y, M, D representing the year, month and date for that day.
Preferably according to the following formula:
Figure BDA0002315510490000125
calculating the terminal-substellar point distance d at the time tTH(t) wherein(s)j,sw) Is the position of the point under the satellite (u) calculated from the ephemerisj,uw) Is the current position that the mobile terminal obtained from the internal positioning module.
The third step: the mobile terminal calculates the ideal relative received signal power s to the serving cellidealAnd (t) predicting the switching trigger time so as to calculate the neighbor list.
Preferably according to the following formula:
Figure BDA0002315510490000131
calculating the half-satellite field angle of the mobile terminal to the service satellite
Figure BDA0002315510490000139
Wherein d isTH(t) represents the terminal-to-subsatellite point distance at time t, RERepresenting the earth radius and h the orbit height.
Preferably according to the following formula:
Figure BDA0002315510490000132
Figure BDA0002315510490000133
Figure BDA0002315510490000134
and calculating the movement direction deflection angle mu (t) of the mobile terminal to the service satellite.
Preferably according to the following formula:
sideal(t)＝10logδ2-Lr(t) [ equation 12]
δ ═ H (u, v) [ equation 13]
Figure BDA0002315510490000135
Figure BDA0002315510490000136
Figure BDA0002315510490000137
Calculating the ideal relative received signal power s of the mobile terminal to the service cell at the time tideal(t) of (d). And δ represents a signal field value at the time t, and δ -H (u, v) represents a mapping relation between UV coordinate system coordinates and field values of the satellite antenna corresponding to the mobile terminal, and is related to the design condition of the antenna. L isr(t) represents the relative path loss of the signal, RERepresenting the radius of the earth, h representing the orbit height,
Figure BDA0002315510490000138
represents the half field angle of the mobile terminal to the service satellite, and the mu (t) represents the movement direction deflection angle of the mobile terminal to the service satellite.
Preferably when:
sideal(t)≤sguarantee
then, predicting the time t as a switching trigger time; otherwise, let t be t + Δ t and jump to the second step. Wherein s isguaranteeThe minimum relative received power of the mobile terminal communication is guaranteed and is determined according to the link budget.
The fourth step: and the mobile terminal calculates the neighbor list. Firstly, calculating the half field angle of the mobile terminal to other satellites in the constellation at the time t, preferably according to the following formula:
Figure BDA0002315510490000141
a decision is made that satellite number i enters the set of overlay satellites, where,
Figure BDA0002315510490000142
is the ideal critical satellite lower half opening angle of the satellite No. i,
Figure BDA0002315510490000143
representing the inferior star half field angle of the mobile terminal to the i-number satellite, the preferred calculation formula is as follows:
Figure BDA0002315510490000144
Figure BDA0002315510490000145
wherein d isTH(t)[i]Represents the distance between the mobile terminal and the satellite-satellite point of the number i, RERepresents the earth radius, h represents the orbital height, (u)j,uw) Representing the position of the mobile terminal,(s)j[i],sw[i]) Representing the position of the satellite under the satellite No. i.
Still more preferably according to the following formula:
Figure BDA0002315510490000146
calculating the movement direction deflection angle mu (t) [ i ] of the mobile terminal to the No. i satellite]。dTH(t)[i]Representing the distance between the mobile terminal and the satellite-satellite point I, and the parameter dTQ(t)[i]The preferred calculation formula of (c):
Figure BDA0002315510490000147
parameter of
Parameter dHQ(t)[i]The preferred calculation formula of (c):
Figure BDA0002315510490000148
the mobile terminal is to
Figure BDA0002315510490000151
μ(t)[i]And comparing the critical power of all wave beams in the No. i satellite, and calculating to obtain a neighbor list of the mobile terminal. The critical power of the beam is determined by the antenna design.
The fifth step: and simultaneously measuring the signal intensity of the beam cell in the service cell and the neighbor cell list. If the intensity of the signal received by the serving cell is less than Pthresh2Then the handover trigger is decided. Pthresh2Is a handover trigger threshold, the preferred calculation formula:
Figure BDA0002315510490000152
Pthresh2＝10logPbeam-Ploss+sguarantee
wherein, PlossRepresents the satellite-borne point path loss of the service satellite, lambda represents the operating wavelength, h represents the orbital altitude, PbeamRepresenting the transmission power of a single beam, sguaranteeRepresenting the minimum relative received power at which the mobile terminal is guaranteed to communicate.
And a sixth step: the mobile terminal calculates the visible time of the pre-screened wave beams one by one through a snapshot method, preferably according to the following formula:
Figure BDA0002315510490000153
where Δ t is the interval of snapshots, r represents the number of snapshots, and preferably satisfies:
sideal(t+rΔt)≤sthresh[i][j]
sideal(t + r Δ t) represents the ideal relative received signal power of the mobile terminal to the j beam of satellite number i at time t + r Δ t, sthresh[i][j]The optimal calculation formula for the visible critical power value of the beam of satellite number j represents the number i:
sthresh[i][j]＝sguarantee+soff[i][j][ equation 16]
Figure BDA0002315510490000154
Wherein s isguaranteeIs to ensure the minimum relative received power, s, of the mobile terminal communicationoff[i][j]Representing the value of the intensity drop, P, of the mobile terminal due to signal fadingideal(t)[i][j]Representing the ideal receiving power, P, of the mobile terminal to the j wave beam of the i satellite at the switching triggering time tmeas(t)[i][j]Representing the actual measured signal strength value of the handoff trigger time t for satellite number i beam number j.
The seventh step: screening the beam cells in the neighbor cell list according to the beam visible time is preferably according to the following formula:
Figure BDA0002315510490000162
wherein, W [ i ] [ j ] represents the beam switching weight of the i number satellite j number beam in the neighbor list, and the preferred calculation formula is as follows:
Figure BDA0002315510490000161
wherein, Pmeas(thandover)[i][j]The measured signal strength of the beam switching triggering moment of the satellite number j in the adjacent area list is represented, and M represents judgmentAnd if the power value of the beam of the broken beam and the power value of the beam of the source beam are constant under the same satellite, the value under the same satellite is 1, and if the power values of the beam of the satellite j and the beam of the satellite i exist under different satellites, the M is 0 under the condition that the visible time is the same, the probability of switching among the satellites is reduced, and when the maximum value is calculated, the beam switching under the same satellite is preferentially selected. t is tvisble[i][j]Representing the visible time of the mobile terminal to the j wave beam of the i-number satellite in the adjacent area list, T representing the maximum value of the visible time of the wave beam in all the adjacent area wave beams, P representing the maximum value of the intensity of the received signal at the switching triggering moment in all the adjacent area wave beams, and TthreshRepresenting the beam visibility time threshold.
If the adjacent area list after screening is empty, t is addedthreshAnd (4) dividing the size by half, and re-screening the original neighbor list. Until the filtered neighbor list is not empty.
And selecting the wave beam cell with the maximum received signal intensity in the screened neighbor cell list as a new service cell and accessing the new service cell.
The invention provides a method and a device for switching cells of a low-orbit satellite constellation system based on ephemeris information. This handover criterion reduces the frequency of mobile terminal handovers starting from the requirements of practical low earth orbit satellite systems.

Claims (6)

1. A cell switching method of a low-orbit satellite constellation system based on ephemeris information is characterized by comprising the following steps:
(1) the mobile terminal receives the signal of the current service cell at the current time t, and judges whether the received signal intensity of the current service cell is smaller than the signal intensity measurement threshold value P of any adjacent service cellthresh1If yes, continuing to execute the step (2); otherwise, the current serving cell does not need to be switched;
(2) the mobile terminal receives broadcast ephemeris information at the moment t, determines the position of the satellite-borne point at the moment t according to the position of the service satellite at the moment t in the broadcast ephemeris information at the moment t, and calculates the distance d from the mobile terminal to the satellite-borne point of the service satellite according to the position of the satellite-borne point at the moment tTH(t)；
(3) The mobile terminal is used for receiving the service satellite down-satellite distance d according to the mobile terminalTH(t) calculating the subsatellite half field angle of the serving satellite
Figure FDA0002315510480000011
And a movement direction declination angle mu (t) according to the half-aperture angle of the satellite under the satellite serving
Figure FDA0002315510480000012
And a motion direction deviation angle mu (t) for calculating the ideal received signal power sideal(t); judgment sideal(t) whether the value is less than or equal to the set ideal communication threshold value, if so, continuing to execute the step (4), otherwise, adding a value after the interval delta t is increased at the moment t to the t, replacing the t in the step (2) and returning to the step (2);
(4) the mobile terminal calculates critical power of all beams in a coverage satellite set of the mobile terminal according to the satellite position at the moment t, and the critical power is compared with the ideal received signal power s in the step (3)ideal(t) comparing, if the comparison result is larger than or equal to the threshold power, putting the wave beam corresponding to the threshold power into a neighbor list of the mobile terminal, otherwise, discarding the wave beam corresponding to the threshold power;
(5) the mobile terminal simultaneously measures the signal intensity of the current service cell and the signal intensity of the wave beam in the neighbor cell list, and judges whether the received signal intensity of the current service cell is smaller than the set switching trigger threshold value Pthresh2If the current cell number is less than the preset value, continuing to execute the step (6), otherwise, the current serving cell does not need to be switched;
(6) calculating the visible time of the wave beams of the mobile terminal corresponding to the wave beams in the neighbor cell list one by one;
(7) mobile terminal screens out less-than-set wave beam visible time threshold t in neighbor listthreshIf the wave beam corresponding to the visible time is screenedIf the neighbor list after division is empty, the set wave beam visible time threshold value t is usedthreshThe size of the neighbor list is reduced by half, and the original neighbor list is screened again until the neighbor list is not empty;
(8) and calculating the beam switching weight values of all the beams in the filtered neighbor cell list, selecting the beam with the maximum beam switching weight value in the neighbor cell list as a target beam, and switching the current beam to the target beam.
2. The ephemeris trajectory prediction based handover method for low earth orbit satellite communication system as claimed in claim 1, wherein the received signal strength P of the serving cellmeasThe formula for calculation of (t) is:
Figure FDA0002315510480000021
where N is the length of the sampling window, Δ t is the interval of measurement, αnIs the weight of the received power at different sampling moments, and P (t-n Δ t) represents the actual received power at t-n Δ t.
3. The ephemeris trajectory prediction based handover method in a low earth orbit satellite communication system of claim 1, wherein the position(s) of the sub-satellite pointj,sw) The calculation formula of (2) is as follows:
Figure FDA0002315510480000022
wherein (x)r,yr,zr) The coordinate of the low earth orbit satellite in the geocentric inertial coordinate system, when GAST represents the Greenwich mean fixed star at the current moment, the GAST is approximately equal to GMST of Greenwich mean fixed star in the numerical value, and the calculation formula is as follows:
Figure FDA0002315510480000031
wherein, the parameter C4、C5Are each oneThe calculation formula of the parameter UT is as follows:
UT mod (JD +0.5,1) [ equation 4]
The JD represents the julian day corresponding to the current day, and the calculation formula is as follows:
Figure FDA0002315510480000032
wherein the parameter Y, M, D represents the year, month and date corresponding to the current day,
Figure FDA0002315510480000033
GMST0representing Greenwich mean time of 0 o' clock in world time, the calculation formula is:
GMST0＝C0+C1T+C2T2-C3T3[ equation 6)]
Wherein, C0、C1、C2And C3All are parameters, T ═ T (JD-2451545.0-UT)/36525.0.
4. The ephemeris trajectory prediction based handover method for a low earth orbit satellite communication system according to claim 1, wherein the calculation formula of the terminal-satellite point distance is:
Figure FDA0002315510480000034
wherein (u)j,uw) Indicating the current location of the mobile terminal,(s)j,sw) Representing the current position of the sub-satellite point, RERepresents the radius of the earth;
the calculation formula of the half aperture angle under the satellite is as follows:
Figure FDA0002315510480000041
wherein d isTH(t) generationTerminal-substellar distance, R, at time tERepresents the earth radius, h represents the orbit height;
the calculation formula of the deflection angle of the motion direction is as follows:
Figure FDA0002315510480000042
wherein R isERepresenting the radius of the earth, parameter dTQ(t) is calculated by the formula
Figure FDA0002315510480000043
Parameter dHQ(t) the calculation formula is:
Figure FDA0002315510480000044
5. the ephemeris trajectory prediction based handover method for low earth orbit satellite communication system according to claim 1, wherein the ideal received signal power is calculated by the following formula:
sideal(t)＝10logδ2-Lr(t) [ equation 12]
Wherein δ represents a signal field value at time t, and the calculation formula is as follows:
δ ═ H (u, v) [ equation 13]
Wherein the content of the first and second substances,
Figure FDA0002315510480000045
h (u, v) represents a UV coordinate system coordinate-field value mapping relationship of the on-satellite antenna corresponding to the mobile terminal; l isr(t) is the relative path loss of the signal, and the calculation formula is as follows:
Figure FDA0002315510480000046
wherein R isERepresenting the radius of the earth, h representing the orbit height,
Figure FDA0002315510480000051
representing the inferior star half opening angle at time t.
6. A low earth orbit satellite communication system ephemeris track prediction based handover apparatus, comprising:
the signal measurement module is used for measuring the signal intensity of the service cell on a service channel and the signal intensity of a pilot signal of an adjacent cell;
the ephemeris information receiving module is used for receiving ephemeris information broadcasted by the satellite-borne base station in a downlink manner;
the mobile terminal positioning module is used for acquiring real-time position information of the mobile terminal;
the ephemeris prediction and satellite node calculation module is used for predicting ephemeris information at the current moment according to the received latest ephemeris information and calculating the satellite node position of the low-orbit constellation;
the signal field value storage module is used for pre-storing the coordinates and the signal field value pairs under the UV coordinate system of each beam internal branch point according to the antenna design condition;
the neighbor cell list calculation module is used for calculating and storing a neighbor cell list of the mobile terminal at the switching triggering moment according to the satellite point information, the mobile terminal position information and the signal field value;
the beam visible time calculation module is used for switching the trigger time and calculating the beam visible time of all beam cells in the neighbor cell list according to the satellite point information, the mobile terminal position information and the signal field value;
and the screening and judging module screens out the best access beam cell for the beam cell in the neighbor cell list according to the visible time of the beam and the intensity of the received signal.
CN201911275733.5A 2019-12-12 2019-12-12 Low-orbit satellite constellation system cell switching method and device based on ephemeris information Active CN111182594B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911275733.5A CN111182594B (en) 2019-12-12 2019-12-12 Low-orbit satellite constellation system cell switching method and device based on ephemeris information

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911275733.5A CN111182594B (en) 2019-12-12 2019-12-12 Low-orbit satellite constellation system cell switching method and device based on ephemeris information

Publications (2)

Publication Number Publication Date
CN111182594A true CN111182594A (en) 2020-05-19
CN111182594B CN111182594B (en) 2022-03-04

Family

ID=70651965

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911275733.5A Active CN111182594B (en) 2019-12-12 2019-12-12 Low-orbit satellite constellation system cell switching method and device based on ephemeris information

Country Status (1)

Country Link
CN (1) CN111182594B (en)

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111464235A (en) * 2020-06-22 2020-07-28 北京前沿探索深空科技有限公司 Low-orbit satellite mobile network switching method and device based on time
CN112054823A (en) * 2020-09-10 2020-12-08 重庆邮电大学 Low-earth-orbit satellite communication switching method
CN112311445A (en) * 2020-10-20 2021-02-02 陕西航天技术应用研究院有限公司 Beam switching method, device and system based on signal ground power calibration value
CN112640531A (en) * 2020-12-08 2021-04-09 北京小米移动软件有限公司 Cell switching method and device, communication equipment and storage medium
CN112653507A (en) * 2020-12-25 2021-04-13 东方红卫星移动通信有限公司 Mobile switching method and system for low-orbit communication satellite constellation
CN112671450A (en) * 2020-12-09 2021-04-16 中国电子科技集团公司第五十四研究所 Low-orbit satellite communication routing area updating method based on terminal position
CN112764067A (en) * 2020-12-23 2021-05-07 深圳创维数字技术有限公司 Method and device for acquiring ephemeris data of GPS (Global positioning System) satellite, and vehicle-mounted and readable storage medium
CN112822738A (en) * 2021-01-14 2021-05-18 重庆邮电大学 Low-orbit satellite communication system switching management method in dense user scene
CN112821941A (en) * 2021-01-14 2021-05-18 重庆邮电大学 Pre-switching method for multi-beam low-orbit satellite communication system
CN113038618A (en) * 2021-05-20 2021-06-25 银河航天(北京)网络技术有限公司 Satellite communication system and method for accessing satellite communication system
CN113038498A (en) * 2021-03-02 2021-06-25 航天科工空间工程发展有限公司 Method for realizing beam-to-ground coverage through low-earth-orbit satellite wave position design
CN113242085A (en) * 2021-05-13 2021-08-10 重庆邮电大学 Terminal position management method of low-earth-orbit satellite network
CN113271558A (en) * 2021-05-08 2021-08-17 东方红卫星移动通信有限公司 Internet of things information transmission method, terminal and system in low-orbit satellite Internet of things
CN113872676A (en) * 2021-09-28 2021-12-31 东方红卫星移动通信有限公司 Switching method and system realized by combining position information and channel measurement information
CN114006642A (en) * 2021-11-02 2022-02-01 东方红卫星移动通信有限公司 Rapid wave beam searching method, terminal and satellite communication system
WO2022032303A1 (en) * 2020-08-06 2022-02-10 Qualcomm Incorporated Switching satellites in fixed radio cell
CN114039641A (en) * 2021-10-08 2022-02-11 中国联合网络通信集团有限公司 Satellite determination method, device, equipment and storage medium
CN114095107A (en) * 2021-11-22 2022-02-25 北京中科晶上科技股份有限公司 Switching simulation method, device and simulation system of satellite mobile communication system
WO2022067760A1 (en) * 2020-09-30 2022-04-07 Oppo广东移动通信有限公司 Cell measurement method, electronic device, and storage medium
CN114342470A (en) * 2020-07-29 2022-04-12 北京小米移动软件有限公司 Satellite communication method and device, storage medium
CN114614884A (en) * 2022-03-18 2022-06-10 中国电子科技集团公司第十研究所 Method for continuously covering beam on non-stationary orbit satellite constellation satellite to ground
CN114828113A (en) * 2021-05-17 2022-07-29 银河航天(北京)网络技术有限公司 Method for user mobility management of constellation communication system
CN115103449A (en) * 2022-08-24 2022-09-23 椭圆时空(北京)科技有限公司 Multi-beam low-orbit satellite space energy distribution method and device and electronic equipment
CN115118324A (en) * 2022-05-31 2022-09-27 北京邮电大学 Satellite-ground converged network switching method based on ephemeris tracking
WO2022247440A1 (en) * 2021-05-27 2022-12-01 广州爱浦路网络技术有限公司 5g core network-based low-earth-orbit satellite paging method, system, and apparatus, and medium
WO2022252160A1 (en) * 2021-06-02 2022-12-08 北京小米移动软件有限公司 Satellite cell position indication method and apparatus, user equipment, network side device, and storage medium
CN115474253A (en) * 2022-11-07 2022-12-13 中国电子科技集团公司第五十四研究所 Satellite network user cross-satellite cross-beam seamless mobile switching method
WO2023011405A1 (en) * 2021-08-04 2023-02-09 展讯通信（上海）有限公司 Method for starting power saving mode, communication apparatus, and readable storage medium
WO2023011530A1 (en) * 2021-08-06 2023-02-09 大唐移动通信设备有限公司 Information processing method and apparatus, and terminal
WO2023087147A1 (en) * 2021-11-16 2023-05-25 北京小米移动软件有限公司 Information processing method and apparatus, and communication device and storage medium
CN117528710A (en) * 2024-01-05 2024-02-06 广东世炬网络科技有限公司 Terminal NTN cell selection method, device, equipment and medium based on management platform
WO2024055316A1 (en) * 2022-09-16 2024-03-21 华为技术有限公司 Parameter determining method and apparatus

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015061983A1 (en) * 2013-10-30 2015-05-07 Qualcomm Incorporated Service continuity for group communications over evolved multimedia broadcast multicast service
CN107454571A (en) * 2017-07-20 2017-12-08 清华大学 A kind of coastal waters user's access switching method towards broadband experience
CN108141277A (en) * 2015-10-13 2018-06-08 高通股份有限公司 For the method and apparatus of the inter-satellite switching in Low Earth Orbit (LEO) satellite system
WO2019027626A1 (en) * 2017-08-01 2019-02-07 Viasat, Inc. Handover based on predicted network conditions
CN110493833A (en) * 2019-08-29 2019-11-22 中国电子科技集团公司第五十四研究所 A kind of autonomous method for handover control of terminal for LEO mobile satellite communication system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015061983A1 (en) * 2013-10-30 2015-05-07 Qualcomm Incorporated Service continuity for group communications over evolved multimedia broadcast multicast service
CN108141277A (en) * 2015-10-13 2018-06-08 高通股份有限公司 For the method and apparatus of the inter-satellite switching in Low Earth Orbit (LEO) satellite system
CN107454571A (en) * 2017-07-20 2017-12-08 清华大学 A kind of coastal waters user's access switching method towards broadband experience
WO2019027626A1 (en) * 2017-08-01 2019-02-07 Viasat, Inc. Handover based on predicted network conditions
CN110493833A (en) * 2019-08-29 2019-11-22 中国电子科技集团公司第五十四研究所 A kind of autonomous method for handover control of terminal for LEO mobile satellite communication system

Non-Patent Citations (7)

* Cited by examiner, † Cited by third party
Title
" "R2-1808961 - Connection control TP"", 《3GPP TSG-RAN WG2 #102 TDOC》 *
刘岩: "网络流量控制若干关键技术研究", 《中国博士学位论文电子期刊网》 *
张姗姗: "基于软件定义卫星网络的低轨卫星切换策略研究", 《中国优秀硕士论文电子期刊网》 *
惠蕾放: "分布式MANET的多址技术及抗毁性研究", 《中国优秀硕士论文电子期刊网》 *
惠蕾放: "无线网络中的资源管理问题研究", 《中国博士学位论文电子期刊网》 *
王祥鹤: "低轨卫星通信系统用户切换方案研究与实现", 《中国优秀硕士论文电子期刊网》 *
赵雨: "车用网络的簇式路由机例研究", 《中国优秀硕士论文电子期刊网》 *

Cited By (52)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111464235A (en) * 2020-06-22 2020-07-28 北京前沿探索深空科技有限公司 Low-orbit satellite mobile network switching method and device based on time
CN111464235B (en) * 2020-06-22 2020-09-25 北京前沿探索深空科技有限公司 Low-orbit satellite mobile network switching method and device based on time
CN114342470A (en) * 2020-07-29 2022-04-12 北京小米移动软件有限公司 Satellite communication method and device, storage medium
WO2022032303A1 (en) * 2020-08-06 2022-02-10 Qualcomm Incorporated Switching satellites in fixed radio cell
CN112054823A (en) * 2020-09-10 2020-12-08 重庆邮电大学 Low-earth-orbit satellite communication switching method
CN112054823B (en) * 2020-09-10 2022-04-15 重庆邮电大学 Low-earth-orbit satellite communication switching method
WO2022067760A1 (en) * 2020-09-30 2022-04-07 Oppo广东移动通信有限公司 Cell measurement method, electronic device, and storage medium
CN112311445B (en) * 2020-10-20 2022-08-23 陕西航天技术应用研究院有限公司 Beam switching method, device and system based on signal ground power calibration value
CN112311445A (en) * 2020-10-20 2021-02-02 陕西航天技术应用研究院有限公司 Beam switching method, device and system based on signal ground power calibration value
CN112640531B (en) * 2020-12-08 2024-04-09 北京小米移动软件有限公司 Cell switching method and device, communication equipment and storage medium
CN112640531A (en) * 2020-12-08 2021-04-09 北京小米移动软件有限公司 Cell switching method and device, communication equipment and storage medium
WO2022120601A1 (en) * 2020-12-08 2022-06-16 北京小米移动软件有限公司 Cell handover method and apparatus, communication device and storage medium
CN112671450A (en) * 2020-12-09 2021-04-16 中国电子科技集团公司第五十四研究所 Low-orbit satellite communication routing area updating method based on terminal position
CN112764067A (en) * 2020-12-23 2021-05-07 深圳创维数字技术有限公司 Method and device for acquiring ephemeris data of GPS (Global positioning System) satellite, and vehicle-mounted and readable storage medium
CN112764067B (en) * 2020-12-23 2023-07-07 深圳创维数字技术有限公司 GPS satellite ephemeris data acquisition method and device, vehicle-mounted and readable storage medium
CN112653507A (en) * 2020-12-25 2021-04-13 东方红卫星移动通信有限公司 Mobile switching method and system for low-orbit communication satellite constellation
CN112653507B (en) * 2020-12-25 2022-07-26 东方红卫星移动通信有限公司 Mobile switching method and system for low-orbit communication satellite constellation
CN112822738B (en) * 2021-01-14 2022-03-11 重庆邮电大学 Low-orbit satellite communication system switching management method in dense user scene
CN112821941B (en) * 2021-01-14 2022-10-21 重庆邮电大学 Pre-switching method for multi-beam low-orbit satellite communication system
CN112822738A (en) * 2021-01-14 2021-05-18 重庆邮电大学 Low-orbit satellite communication system switching management method in dense user scene
CN112821941A (en) * 2021-01-14 2021-05-18 重庆邮电大学 Pre-switching method for multi-beam low-orbit satellite communication system
CN113038498B (en) * 2021-03-02 2022-09-23 航天科工空间工程发展有限公司 Method for realizing beam-to-ground coverage through low-earth-orbit satellite wave position design
CN113038498A (en) * 2021-03-02 2021-06-25 航天科工空间工程发展有限公司 Method for realizing beam-to-ground coverage through low-earth-orbit satellite wave position design
CN113271558A (en) * 2021-05-08 2021-08-17 东方红卫星移动通信有限公司 Internet of things information transmission method, terminal and system in low-orbit satellite Internet of things
CN113242085A (en) * 2021-05-13 2021-08-10 重庆邮电大学 Terminal position management method of low-earth-orbit satellite network
CN114828113B (en) * 2021-05-17 2023-10-20 银河航天(北京)网络技术有限公司 Method for managing user mobility of constellation communication system
CN114828113A (en) * 2021-05-17 2022-07-29 银河航天(北京)网络技术有限公司 Method for user mobility management of constellation communication system
CN113038618B (en) * 2021-05-20 2021-09-14 银河航天(北京)网络技术有限公司 Satellite communication system and method for accessing satellite communication system
CN113038618A (en) * 2021-05-20 2021-06-25 银河航天(北京)网络技术有限公司 Satellite communication system and method for accessing satellite communication system
WO2022247440A1 (en) * 2021-05-27 2022-12-01 广州爱浦路网络技术有限公司 5g core network-based low-earth-orbit satellite paging method, system, and apparatus, and medium
WO2022252160A1 (en) * 2021-06-02 2022-12-08 北京小米移动软件有限公司 Satellite cell position indication method and apparatus, user equipment, network side device, and storage medium
WO2023011405A1 (en) * 2021-08-04 2023-02-09 展讯通信（上海）有限公司 Method for starting power saving mode, communication apparatus, and readable storage medium
WO2023011530A1 (en) * 2021-08-06 2023-02-09 大唐移动通信设备有限公司 Information processing method and apparatus, and terminal
CN113872676A (en) * 2021-09-28 2021-12-31 东方红卫星移动通信有限公司 Switching method and system realized by combining position information and channel measurement information
CN113872676B (en) * 2021-09-28 2023-09-01 东方红卫星移动通信有限公司 Switching method and system realized by combining position information and channel measurement information
CN114039641A (en) * 2021-10-08 2022-02-11 中国联合网络通信集团有限公司 Satellite determination method, device, equipment and storage medium
CN114006642B (en) * 2021-11-02 2024-02-27 中国星网网络应用有限公司 Quick beam searching method, terminal and satellite communication system
CN114006642A (en) * 2021-11-02 2022-02-01 东方红卫星移动通信有限公司 Rapid wave beam searching method, terminal and satellite communication system
WO2023087147A1 (en) * 2021-11-16 2023-05-25 北京小米移动软件有限公司 Information processing method and apparatus, and communication device and storage medium
CN114095107B (en) * 2021-11-22 2023-09-05 北京中科晶上科技股份有限公司 Switching simulation method, device and simulation system of satellite mobile communication system
CN114095107A (en) * 2021-11-22 2022-02-25 北京中科晶上科技股份有限公司 Switching simulation method, device and simulation system of satellite mobile communication system
CN114614884A (en) * 2022-03-18 2022-06-10 中国电子科技集团公司第十研究所 Method for continuously covering beam on non-stationary orbit satellite constellation satellite to ground
CN114614884B (en) * 2022-03-18 2023-05-26 中国电子科技集团公司第十研究所 Method for continuously covering satellite wave beam of non-stationary orbit satellite on ground
CN115118324A (en) * 2022-05-31 2022-09-27 北京邮电大学 Satellite-ground converged network switching method based on ephemeris tracking
CN115118324B (en) * 2022-05-31 2023-12-01 北京邮电大学 Star-ground fusion network switching method based on ephemeris tracking
CN115103449B (en) * 2022-08-24 2022-11-15 椭圆时空(北京)科技有限公司 Multi-beam low-orbit satellite space energy distribution method and device and electronic equipment
CN115103449A (en) * 2022-08-24 2022-09-23 椭圆时空(北京)科技有限公司 Multi-beam low-orbit satellite space energy distribution method and device and electronic equipment
WO2024055316A1 (en) * 2022-09-16 2024-03-21 华为技术有限公司 Parameter determining method and apparatus
CN115474253B (en) * 2022-11-07 2023-02-07 中国电子科技集团公司第五十四研究所 Satellite network user cross-satellite cross-beam seamless mobile switching method
CN115474253A (en) * 2022-11-07 2022-12-13 中国电子科技集团公司第五十四研究所 Satellite network user cross-satellite cross-beam seamless mobile switching method
CN117528710A (en) * 2024-01-05 2024-02-06 广东世炬网络科技有限公司 Terminal NTN cell selection method, device, equipment and medium based on management platform
CN117528710B (en) * 2024-01-05 2024-05-03 广东世炬网络科技股份有限公司 Terminal NTN cell selection method, device, equipment and medium based on management platform

Also Published As

Publication number Publication date
CN111182594B (en) 2022-03-04

Similar Documents

Publication Publication Date Title
CN111182594B (en) Low-orbit satellite constellation system cell switching method and device based on ephemeris information
CN111371486B (en) Method, system, device and storage medium for beam switching based on low earth orbit satellite
EP3513510B1 (en) Neighbor cell list in a satellite communication system
CN111525950A (en) Terminal access and switching method for low-orbit mobile satellite communication system
RU2123762C1 (en) Method for prediction of cell-to-cell communication in satellite cellular communication network
CN111756414B (en) Beam switching method and related equipment
CN112821941B (en) Pre-switching method for multi-beam low-orbit satellite communication system
CN110493833A (en) A kind of autonomous method for handover control of terminal for LEO mobile satellite communication system
CN1122959A (en) Antenna for multipath satellite communication links
US7474873B2 (en) Satellite mobile telephone cell departure prediction
JPH05218928A (en) Method of changing over communication in communication system by low-orbit satellite for terminal device and communication system using said method
KR100617812B1 (en) Mobile terminal for performing handoff using location information and method therefor
CN104735738A (en) Switching method in GMR-1 satellite mobile communication system
CN113613208A (en) Method for wireless communication of aircraft via land network and airborne system
CN115173934B (en) Beam switching method and system
Park et al. Trends in LEO satellite handover algorithms
CN111836315A (en) Joint switching method, device, equipment and storage medium
EP4195764A1 (en) Cell selection method and apparatus, device and medium
Euler et al. Using 3GPP technology for satellite communication: Most Satellite Communication Today is Based on Proprietary Solutions, But That May Soon Change. Non-Terrestrial Networks Became Part of the 3rd Generation Partnership Project Standard in Release 17, Establishing a Strong Foundation for Direct Communication Between Satellites, Smartphones and Other Types of Mass-Market User Equipment
Zou et al. Dynamic channel allocation strategy of satellite communication systems based on grey prediction
Rehman et al. Optimizing satellite handover rate using particle swarm optimization (pso) algorithm
US7317895B2 (en) Method of controlling a satellite communication system, a timing unit, and a control unit of a timing unit
CN113972945A (en) Handover method, apparatus, storage medium, and wireless communication system
Lin et al. A novel method to determine the handover threshold based on reconfigurable factor graph for LEO satellite internet network
CN113965243B (en) Low-orbit satellite communication method, device, electronic equipment and storage medium

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant