CN107395299B - Interference analysis method for 450MHz frequency band satellite meteorological service and railway train dispatching system - Google Patents

Interference analysis method for 450MHz frequency band satellite meteorological service and railway train dispatching system Download PDF

Info

Publication number
CN107395299B
CN107395299B CN201710535011.3A CN201710535011A CN107395299B CN 107395299 B CN107395299 B CN 107395299B CN 201710535011 A CN201710535011 A CN 201710535011A CN 107395299 B CN107395299 B CN 107395299B
Authority
CN
China
Prior art keywords
interference
value
gain
train
case
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.)
Active
Application number
CN201710535011.3A
Other languages
Chinese (zh)
Other versions
CN107395299A (en
Inventor
胡欣
李博
王卫东
刘帅军
崔高峰
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.)
Beijing University of Posts and Telecommunications
Original Assignee
Beijing University of Posts and Telecommunications
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 Beijing University of Posts and Telecommunications filed Critical Beijing University of Posts and Telecommunications
Priority to CN201710535011.3A priority Critical patent/CN107395299B/en
Publication of CN107395299A publication Critical patent/CN107395299A/en
Application granted granted Critical
Publication of CN107395299B publication Critical patent/CN107395299B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/30—Monitoring; Testing of propagation channels
    • H04B17/309—Measuring or estimating channel quality parameters
    • H04B17/345—Interference values
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/02—Arrangements for optimising operational condition

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Quality & Reliability (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Radio Relay Systems (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

The invention discloses an interference analysis method for a weather service and railway train dispatching system of a 450MHz frequency band satellite, belonging to the field of interference analysis of a mobile scene and a low-orbit satellite. The invention uses the parameters of the Argos system and the railway train dispatching system in practical application, combines antenna directional diagrams provided by ITU in different systems and different services and the orbit operation rule of meteorological satellites in the Argos system, analyzes four interference conditions, dynamically analyzes the interference under different conditions, selects a dynamic channel propagation model and a system dynamic interference threshold value, corrects the propagation path loss under the four interference conditions by using a least square method, and analyzes whether the interference exists between the low-orbit satellite and the ground mobile system. The interference analysis method reflects the performance of an actual link, improves the accuracy of interference analysis, provides a uniform interference analysis form, and has wider application range.

Description

Interference analysis method for 450MHz frequency band satellite meteorological service and railway train dispatching system
Technical Field
The invention belongs to the field of interference analysis of a mobile scene and a low-orbit satellite, and provides an interference analysis method of a weather service and railway train dispatching system of a 450MHz frequency band satellite.
Background
In 11 months of 2015, world radio congress of the International Telecommunications Union (ITU), 28 topics were proposed for a new research period from 2015 to 2019. Among them, in issue 1.3, according to resolution 766 of WRC-15, the possibility of upgrading the secondary division of satellite weather services (air-to-ground) to the primary division and providing the primary division for satellite earth sounding services (air-to-ground) in the 460-470MHz band is considered.
The 450MHz frequency band is one of the earliest used frequency bands in China, and is mainly used for fixed and mobile services. As shown in FIG. 1, the 457.200-458.650 MHz/467.2-468.675 MHz frequency band is allocated to train dispatching; the Argos system is a data collection and positioning satellite communication system jointly established in the United states and France, the system space section consists of polar orbit meteorological satellites, various environment detection data are transmitted by utilizing the polar orbit meteorological satellites, and a service uplink of the meteorological satellite system works in a frequency band of 401 plus 403 MHz; the downlink works in a frequency band of 460-470MHz, and the frequency band is overlapped with a frequency band used by a railway train dispatching system, so that the method has important significance for the interference coexistence research of the Argos system downlink and the railway train dispatching system.
Along with the increasing of various wireless applications, the problem of spectrum shortage is increasingly serious, and more researches are carried out on the problem of system coexistence under the condition of same frequency or adjacent frequency; the co-frequency deployment of the 5G small cellular network and the fixed satellite earth station has the possibility of coexistence by using a large number of antenna arrays and reasonably setting the protection distance. The interference between a 17.7-19.7 GHz ground system and a satellite system can be evaluated by using a database of a European country and a proper propagation model; on the 450MHz frequency band, the coexistence research of the railway train dispatching system and other systems can be obtained by deterministic calculation, and the interference can be avoided by certain measures. However, there is no research on how to influence the two systems and solve the coexistence problem in the dynamic scene after the introduction of the satellite weather service (air-to-ground) in the 450MHz frequency band.
Disclosure of Invention
The invention provides an interference analysis method of weather service and railway train dispatching system of a 450MHz frequency band satellite aiming at the interference problem of a low earth orbit satellite and a ground mobile system, which comprises the following steps:
aiming at a 450MHz frequency band, a railway train dispatching system and a satellite meteorological service downlink frequency band coexist with same frequency and adjacent frequency to obtain four interference conditions;
the four interference cases are as follows: 1) the transmission of meteorological satellites interferes with the reception of trains; 2) the transmission of meteorological satellites interferes with the reception of railway stations; 3) the emission of the railway station interferes with the reception of the meteorological satellite earth station; 4) the transmission of the train interferes with the reception of the meteorological satellite earth station.
Wherein the cases of 2) and 4) are coexistence of interference in adjacent frequency; the 1) and 3) cases are adjacent frequency and co-frequency coexistence;
step two, when the meteorological satellite and the railway train dispatching system are positioned in the same wave beam coverage area, respectively calculating the received power P in four interference conditionsr；
For four different interference situations, the following formula is adopted to calculate the received power Pr：
Pr＝Pt+Gt+Gr-Lp-ACIR
PrRepresents the received power; the method specifically comprises the following steps: the 1) case is a reception power value of the train; the 2) case is the reception power value of the train station; the reception power values of the meteorological satellite earth station in the cases of 3) and 4);
Ptis the transmit power of the offending system; the method specifically comprises the following steps: in cases 1) and 2) PtAre the transmitting power of meteorological satellites; case 3) of PtIs the transmission power of the railway station; case 4) PtIs the transmission power of the train;
Gtgain for the transmit antenna; the method specifically comprises the following steps: 1) and 2) cases GtThe gain of the transmitting antenna is the meteorological satellite; case 3) of PtGain for the transmitting antenna of the railway station; case 4) PtA transmit antenna gain for the train;
Grgain for the receive antenna; the method specifically comprises the following steps: case 1) GrA receive antenna gain for the train; case 2) GrGain for the receiving antenna of the railway station; g in cases 3) and 4)rThe gain of the receiving antenna of the meteorological satellite earth station;
for the 1) case and the 2) case, when the meteorological satellite generates interference to the ground, the pitch angle of the receiving antenna relative to the maximum gain is different, and the value of the receiving gain is influenced; the method comprises the following specific steps:
Figure BDA0001340067770000021
g (θ) represents a gain with respect to the omni-directional antenna; theta is the pitch relative to the maximum gain (-90 DEG-theta-90 DEG); g0Represents the maximum gain in the azimuth plane; theta3Is a 3dB beam width in the elevation plane; k represents a parameter that accounts for the side lobe level being above a value predicted by the antenna for improved side lobe performance;
for the case of 3) and the case of 4), when considering interference of a train or a train station to a satellite earth station, the satellite follows an angle deviating from the axial direction
Figure BDA0001340067770000022
The antenna gain in the horizontal direction of the earth station is different, and the specific calculation is as follows:
Figure BDA0001340067770000023
Figure BDA0001340067770000024
Figure BDA0001340067770000025
Figure BDA0001340067770000026
wherein the content of the first and second substances,
Figure BDA0001340067770000027
is the gain of the receiving antenna; gmaxIs the antenna main lobe gain; d is the diameter of the antenna, and lambda is the wavelength;
Figure BDA0001340067770000028
is an angle off axial;
Figure BDA0001340067770000029
is the first side-lobe gain.
LpIs the propagation path loss; the corresponding values in the four interference cases are different;
ACIR is the isolation provided by each interference situation under different frequency intervals; the calculation formula is as follows:
Figure BDA0001340067770000031
ACLR represents the adjacent channel leakage power ratio of the offending system; the method specifically comprises the following steps: in the cases of 1) and 2), the ACLR is the adjacent channel leakage power ratio of the meteorological satellite; ACLR in the case of 3) is the adjacent channel leakage power ratio of the railway station; ACLR is the adjacent channel leakage power ratio of the train in the case of 4);
ACS represents the adjacent channel selectivity value of the victim system; the method specifically comprises the following steps: ACS is the adjacent channel selectivity value of the train in case 1); ACS is the adjacent channel selectivity value of the train station in case 2); ACS in the cases of 3) and 4) is the adjacent channel selectivity value of the meteorological satellite earth station;
grouping the four interference situations pairwise, and respectively selecting a static interference threshold value and a dynamic interference evaluation standard;
the four interference situation groups are specifically:
the 1) and 2) cases are taken as a group, and a static interference threshold value is adopted;
the cases of the 3) and the 4) are taken as a group, the dynamic interference evaluation standard is adopted, and the specific parameter is an allowable interference limit value Ilimit(ii) a The method specifically comprises the following steps: i islimit＝N0(Mq-1),M＞Mmin。
N0Is the noise power spectral density; m is the threshold margin of the actual link; q is a margin loss factor; mminIs the minimum value of the threshold margin M.
Step four, correcting transmission in four interference conditions by adopting SPM standard transmission model and using least square methodPropagation path loss value Lp'；
The method comprises the following specific steps:
step 401, for a certain interference situation, giving initial values of each coefficient in an SPM standard propagation model, and calculating a corresponding propagation path loss value L;
L＝(k1+k2×lgf+k3×lghTseff+k4×lgd+k5×lgd×lghTseff+k6×lghRseff)+(k7×Diff+Ccluster)
wherein k is1，k2，k3，k4，k5，k6And k7F is the coefficient of the median propagation path loss, and is the central frequency value; h isTseffIs the effective height value of the transmitting antenna in the interference situation; d is the distance between the transmitting end and the receiving end in the interference situation; h isRseffIs the effective height value of the receiving antenna in the interference situation; diff is the diffraction loss value; cclusterA total terrain correction factor for the interference condition; k is a radical of1，k2，k3，k4，k5，k6And k7Together forming a coefficient matrix K;
step 402, according to the initial value of the actually measured path loss matrix Y, iteration is started to obtain a residual vector delta after k iterationsk；
Y＝(y1y2...ym)T＝AK+BC
And C is a coefficient matrix of random variables of the propagation loss.
The specific process is as follows:
first, the result of the K-1 iteration is Kk-1And Ck-1By AKk＝Y-BCk-1And a matrix solving method of a least square method to obtain a component coefficient Kk；
Then, according to BCk＝Y-AKkAnd a matrix solving method of a least square method to obtain a random component coefficient Ck；
Finally, a residual vector after k iterations is obtained: deltak＝Y-BCk-AKk；
Step 403, determining residual vector deltakWhether convergence is achieved or not, if yes, the correction is finished, and the initial coefficient is successfully corrected; propagation path loss value Lp'The same as the propagation path loss value L; otherwise, continuing iteration until reaching the maximum iteration times, and performing a new round of correction.
Step five, according to the corrected propagation path loss value L in the four interference conditionsp'Recalculating received power P for four interference scenariosr'；
Step six, judging the receiving power P in each interference situation which is recalculated one by onerWhether' is greater than a static interference threshold or a dynamic interference evaluation criterion; if so, indicating that the interference exists in the interference situation, otherwise, indicating that the interference does not exist.
The specific analysis is as follows:
calculating the received power P of the train in case 1)rIf the static interference threshold value is larger than the static interference threshold value, the transmission of the meteorological satellite can interfere the reception of the train;
calculating the received power P of the railway station in case 2)rIf the static interference threshold value is larger than the static interference threshold value, the transmission of the meteorological satellite can interfere the reception of the railway station;
calculating the received power P of the meteorological satellite earth station in case 3)rIf the signal is larger than the dynamic interference evaluation standard, the signal indicates that the emission of the railway station can interfere the reception of the meteorological satellite earth station;
computing received power P of meteorological satellite earth station in case 4)r' greater than the dynamic interference assessment criteria, indicates that the transmission of the train interferes with the reception of the meteorological satellite earth station.
The invention has the advantages that:
1) the interference analysis method for the satellite meteorological service and railway train dispatching system in the 450MHz frequency band reflects the performance of an actual link and improves the accuracy of interference analysis.
2) The interference analysis method for the 450MHz frequency band satellite meteorological service and railway train dispatching system provides a uniform interference analysis form, and is wider in application range.
Drawings
FIG. 1 is a prior art scheme of frequency allocation for railroad train dispatch and meteorological satellites;
FIG. 2 is a flowchart of an interference analysis method for a 450MHz frequency band satellite weather service and railway train dispatching system according to the invention;
FIG. 3 is a schematic diagram of 4 interference scenarios coexisting between the satellite weather and railway train dispatching systems of the present invention;
FIG. 4 is a diagram of the elevation position of the receiving antenna of the present invention when a meteorological satellite interferes with the ground;
FIG. 5 is a graph of the relationship between the elevation angle of the receiving antenna and the receiving gain of the ground according to the present invention;
FIG. 6 is a model of the off-axis angle calculation of the present invention;
FIG. 7 is a graph of receive gain versus off-axis angle for a satellite earth station in accordance with the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples.
According to the ITU-R SA.1162-2 recommendation, the uplink of a polar orbit meteorological satellite Data Collection System (DCS) is 401-403MHz, and the downlink is 460-470 MHz; considering the frequency band planning of the railway train dispatching system, the direct co-frequency and adjacent frequency coexistence of the downlink frequency band of the satellite meteorological service and the railway train dispatching system exists, the interference analysis method of the 450MHz frequency band satellite meteorological service and the railway train dispatching system is provided, the parameters of the Argos system and the railway train dispatching system in practical application are used, and the dynamic analysis is carried out on the interference under four conditions by combining antenna directional patterns provided by ITU in different systems and different services and the meteorological satellite orbit operation rule in the Argos system; and aiming at the interference under different conditions, selecting a dynamic channel propagation model and a system dynamic interference threshold value, and analyzing the interference between the low-orbit satellite and the ground mobile system.
As shown in fig. 2, the specific steps are as follows:
aiming at a 450MHz frequency band, a railway train dispatching system and a satellite meteorological service downlink frequency band coexist with same frequency and adjacent frequency to obtain four interference conditions;
considering that trains and train stations, etc. in the railway train dispatching system are mainly transmitting and receiving ends, the coexistence scene is as shown in fig. 3:
the method specifically comprises the following steps: a) the transmission of meteorological satellites interferes with the reception of trains; b) the transmission of meteorological satellites interferes with the reception of railway stations; c) the emission of the railway station interferes with the reception of the meteorological satellite earth station; d) the transmission of the train interferes with the reception of the meteorological satellite earth station. The meteorological satellite and the meteorological satellite earth station are in normal communication, and the railway station and the train are in normal communication.
In the cases of the 2) and the 4), the interference coexistence under adjacent frequency needs to be analyzed by the meteorological satellite to the railway station and the railway to the meteorological satellite earth station; the meteorological satellite is opposite to the train in the 1) and 3) cases, and the railway station is opposite to the meteorological satellite earth station and not only analyzes the adjacent frequency but also analyzes the coexistence condition under the same frequency.
Step two, when the meteorological satellite and the railway train dispatching system are positioned in the same wave beam coverage area, respectively calculating the received power P in four interference conditionsr；
For four different interference situations, the following formula is adopted to calculate the received power Pr：
Pr＝Pt+Gt+Gr-Lp-ACIR
PrRepresents the received power; the method specifically comprises the following steps: the 1) case is a reception power value of the train; the 2) case is the reception power value of the train station; the reception power values of the meteorological satellite earth station in the cases of 3) and 4);
Ptis the transmit power of the offending system; the method specifically comprises the following steps: in cases 1) and 2) PtAre the transmitting power of meteorological satellites; case 3) of PtIs the transmission power of the railway station; case 4) PtIs the transmission power of the train;
Gtgain for the transmit antenna; the method specifically comprises the following steps: first, the1) And 2) case GtThe gain of the transmitting antenna is the meteorological satellite; case 3) of PtGain for the transmitting antenna of the railway station; case 4) PtA transmit antenna gain for the train;
Grgain for the receive antenna; the method specifically comprises the following steps: case 1) GrA receive antenna gain for the train; case 2) GrGain for the receiving antenna of the railway station; g in cases 3) and 4)rThe antenna gains are all received antenna gains of a meteorological satellite earth station;
for the cases 1) and 2), when the meteorological satellite interferes with the ground, the elevation angle of the receiving antenna influences the value of the receiving gain;
as shown in fig. 4, assuming that the earth is a regular sphere, the radius of the receiving point is similar to the radius of the regular sphere; the Argos meteorological satellite runs on a near polar earth orbit, which is approximately circular and perpendicular to the equatorial plane. By the concept and the assumed condition of the elevation angle, the S point is a meteorological satellite, the P point is a meteorological satellite earth station, the O point is the earth center, and theta is the elevation angle.
When analyzing the interference of the meteorological satellite to the ground, for the antenna radiation pattern of the receiver, considering the omnidirectional antenna, the calculation formula of the receiving gain is as follows,
Figure BDA0001340067770000061
wherein G (θ) represents a gain with respect to the omni-directional antenna; theta is the pitch relative to the maximum gain (-90 DEG-theta-90 DEG); g0Represents the maximum gain in the azimuth plane; theta3For a 3dB beam width in the elevation plane,
Figure BDA00013400677700000610
k represents a parameter that accounts for the side lobe level being above the value predicted by the antenna for improved side lobe performance, taken here to be 0.7. When G is0Taking a relation graph of receiving gain at 10dB and the elevation angle of a receiving antenna, as shown in FIG. 5; when the elevation angle is 0 degree, the receiving gain is maximum, and the gain is increased along with the elevationThe increase in angle decreases the receive gain in the range-180 deg. -0 deg. and 0 deg. -180 deg..
For the case 3) and the case 4), when the interference of the train or the train station to the satellite earth station is considered, the reception gain is decreased as the off-axis angle is increased.
When considering the interference of a train or train station to a satellite earth station, the satellite earth station antenna radiation pattern is seen as a function of off-axis angle. Wherein the off-axis angle of the direction of the disturbance system relative to the main axis direction of the satellite earth station
Figure BDA0001340067770000062
Calculating according to the calculation method shown in FIG. 6; meanwhile, the protection distance between the disturbance system and the satellite earth station can be obtained through geometric analysis.
Using the model in ITU-R P.452-15, the antenna gain in the horizontal direction of the earth station is calculated as follows:
Figure BDA0001340067770000063
Figure BDA0001340067770000064
Figure BDA0001340067770000065
Figure BDA0001340067770000066
wherein the content of the first and second substances,
Figure BDA0001340067770000067
a first side-lobe gain; gmaxIs the antenna main lobe gain;
Figure BDA0001340067770000068
is the antenna gain;
Figure BDA0001340067770000069
is an angle off axial; d is the antenna diameter and λ is the wavelength, both expressed in the same unit.
The specific reference radiation pattern is shown in fig. 7: the satellite earth station reception gain versus off-axis angle is plotted, with the off-axis angle increasing and the reception gain decreasing within the range of 0-180.
LpIs the propagation path loss; the corresponding values in the four interference cases are different;
ACIR is the isolation provided by each interference situation under different frequency intervals; the formula of calculation according to the relevant standard of 3GPP is:
Figure BDA0001340067770000071
ACLR represents the adjacent channel leakage power ratio of the offending system; the method specifically comprises the following steps: in the cases of 1) and 2), the ACLR is the adjacent channel leakage power ratio of the meteorological satellite; ACLR in the case of 3) is the adjacent channel leakage power ratio of the railway station; ACLR is the adjacent channel leakage power ratio of the train in the case of 4);
ACS represents the adjacent channel selectivity value of the victim system; the method specifically comprises the following steps: ACS is the adjacent channel selectivity value of the train in case 1); ACS is the adjacent channel selectivity value of the train station in case 2); ACS in the cases of 3) and 4) is the adjacent channel selectivity value of the meteorological satellite earth station;
in order to obtain the extra isolation under four kinds of interference, when analyzing the adjacent channel interference, the invention adopts a calculation scheme based on ACIR, namely the adjacent channel interference rejection ratio, which is specifically as follows: a. theaddiso＝Pt+Gt+Gr-Lp-ACIR-Ilimit
IlimitFor the interference threshold value, four interference conditions are determined according to different rules;
Aaddisorepresenting the required isolation; the method specifically comprises the following steps: under the condition of 1), the same frequency and adjacent frequency are considered simultaneously, the longitude difference between the meteorological satellite and the train is taken as zero, and the analysis is not carried outIsolation between the two in the same latitude area.
In case 2), only the adjacent frequencies, A, are consideredaddisoThe isolation between the meteorological satellite and the railway station;
and 3) under the condition of simultaneously considering the same frequency and adjacent frequency, an interference coordination contour line can be made when different elevation angles exist, and the isolation distance is seen from the contour line, so that the judgment is made.
4) in case of considering only adjacent frequency, interference coordination contour line can be made at different elevation angles.
Both ACLR and ACS are generally given in the specification, the non-ideal characteristics of the transmitting end and the receiving end are comprehensively characterized by ACIR, and the influence of ACIR is not considered under the same frequency condition, and the following formula is adopted for calculation: a. theaddiso＝Pt+Gt+Gr-Lp-Ilimit(ii) a And the space isolation distance required by coexistence of the transmitting end and the receiving end system can be obtained by combining the propagation model.
Grouping the four interference situations pairwise, and respectively selecting a static interference threshold value and a dynamic interference evaluation standard;
in the selection of the interference threshold, long-term and short-term constraints in a dynamic scene are considered simultaneously; the four interference situation groups are specifically:
the 1) and 2) cases are taken as a group, and a static interference threshold value is adopted; when the railway station and the train are used as receivers, the selected static interference threshold values are all-128 dBm;
the cases of the 3) and the 4) are taken as a group, the dynamic interference evaluation standard is adopted, and the specific parameter is an allowed interference threshold value Ilimit(ii) a The method specifically comprises the following steps: i islimit＝N0(Mq-1),M＞Mmin。
N0Is the noise power spectral density; m is the threshold margin of the actual link; q is a margin loss factor; for the system, considering the influence of the instability of the equipment, the aging of the device and other factors, a minimum value M of a threshold margin M usually existsminThe minimum value of the threshold margin MminAnd should be strictly protected.
Interference threshold value IlimitAnd a thresholdThe margin M is related to a margin loss factor q, q represents the percentage of the allowed loss part, and the value of q has certain floating amount; due to the existence of the interference signal, part of link margin can be consumed, namely, a part of system margin M can be lost, the percentage of the allowed lost part is q, and the value of q is determined by the actual performance and the operating environment of the receiving system and is usually 0.33-0.6.
Step four, correcting the propagation path loss value L in four interference conditions by adopting an SPM standard propagation model and using a least square methodp'；
Aiming at the mobile propagation model, an SPM (Standard deployment model) standard propagation model is uniformly adopted in the calculation of the path loss, the application range is wide, and the formula form can unify most propagation models, so that a standard template is provided for the correction of the propagation model. The SPM model can be used for distinguishing and analyzing a near area/a far area and a visual distance/a non-visual distance under four conditions by adopting different constant terms (K1) and distance factors (K2) and changing coefficients from fixed to variable, increasing the influence of ground object diffraction and carrying out coefficient correction on the coefficients under different interference conditions by using a least square algorithm.
The method comprises the following specific steps:
step 401, for a certain interference situation, giving initial values of each coefficient in an SPM standard propagation model, and calculating a corresponding propagation path loss value L;
L＝(k1+k2×lgf+k3×lghTseff+k4×lgd+k5×lgd×lghTseff+k6×lghRseff)+(k7×Diff+Ccluster)
＝L1+L2
wherein k is1，k2，k3，k4，k5，k6And k7The coefficients of the propagation path loss median value jointly form a coefficient matrix K; l is1Median propagation loss; l is2Is a propagation loss random variable; f is the central frequency value; h isTseffIs the effective height value of the transmitting antenna in the interference situation; d is theDistance between the transmitting end and the receiving end in case of interference; h isRseffIs the effective height value of the receiving antenna in the interference situation; diff is the diffraction loss value; cclusterA total terrain correction factor for the interference condition; the calculation formula is as follows:
Figure BDA0001340067770000081
clu (j) is the jth formation correction factor, OjAre the coefficients on this path.
Step 402, according to the initial value of the actually measured path loss matrix Y, iteration is started to obtain a residual vector delta after k iterationsk；
Assuming that the known measured path loss matrix Y is: y ═ Y1y2...ym)TLet Y be AK + BC; and C is a coefficient matrix of random variables of the propagation loss.
The specific process is as follows:
first, the result of the K-1 iteration is Kk-1And Ck-1Obtaining AK according to the equation Y-AK + BCk＝Y-BCk-1Obtaining a propagation loss median component coefficient K by a matrix solving method of a least square methodk；
Then, BC is obtained according to the equation Y ═ AK + BCk＝Y-AKkThe matrix solving method of the least square method is adopted to obtain the random component coefficient C of the propagation lossk；
Finally, a residual vector after k iterations is obtained: deltak＝Y-BCk-AKk；
Step 403, determining residual vector deltakWhether convergence is achieved or not, if yes, the correction is finished, and the initial coefficient is successfully corrected; propagation path loss value Lp'The same as the propagation path loss value L; otherwise, continuing iteration until reaching the maximum iteration times, and performing a new round of correction.
Step five, according to the corrected propagation path loss value L in the four interference conditionsp'Recalculating received power P for four interference scenariosr'；
Step six, judging the weight one by oneNewly calculated received power P in each interference situationrWhether' is greater than a static interference threshold or a dynamic interference evaluation criterion; if so, indicating that the interference exists in the interference situation, otherwise, indicating that the interference does not exist.
The specific analysis is as follows:
calculating the received power P of the train in case 1)rIf the static interference threshold value is larger than the static interference threshold value, the transmission of the meteorological satellite can interfere the reception of the train;
calculating the received power P of the railway station in case 2)rIf the static interference threshold value is larger than the static interference threshold value, the transmission of the meteorological satellite can interfere the reception of the railway station;
calculating the received power P of the meteorological satellite earth station in case 3)rIf the signal is larger than the dynamic interference evaluation standard, the signal indicates that the emission of the railway station can interfere the reception of the meteorological satellite earth station;
computing received power P of meteorological satellite earth station in case 4)r' greater than the dynamic interference assessment criteria, indicates that the transmission of the train interferes with the reception of the meteorological satellite earth station.

Claims (2)

1. A method for analyzing interference of a 450MHz frequency band satellite meteorological service and a railway train dispatching system is characterized by comprising the following specific steps:
aiming at a 450MHz frequency band, a railway train dispatching system and a satellite meteorological service downlink frequency band coexist with same frequency and adjacent frequency to obtain four interference conditions;
the four interference cases are as follows: 1) the transmission of meteorological satellites interferes with the reception of trains; 2) the transmission of meteorological satellites interferes with the reception of railway stations; 3) the emission of the railway station interferes with the reception of the meteorological satellite earth station; 4) the emission of the train interferes with the reception of the meteorological satellite earth station;
wherein, the 2) and 4) cases are the coexistence of interference under adjacent frequency; the 1) and 3) cases are adjacent frequency and co-frequency coexistence;
step two, when the meteorological satellite and the railway train dispatching system are positioned in the same wave beam coverage area, respectively calculating the received power P in four interference conditionsr；
Calculating the received power P in four interference situationsrThe formula of (1) is as follows:
Pr＝Pt+Gt+Gr-Lp-ACIR
Prrepresents the received power; the method specifically comprises the following steps: the 1) case is a reception power value of the train; the 2) case is the reception power value of the train station; the reception power values of the meteorological satellite earth station in the cases of 3) and 4);
Ptis the transmit power of the offending system; the method specifically comprises the following steps: in cases 1) and 2) PtAre the transmitting power of meteorological satellites; case 3) of PtIs the transmission power of the railway station; case 4) PtIs the transmission power of the train;
Gtgain for the transmit antenna; the method specifically comprises the following steps: 1) and 2) cases GtThe gain of the transmitting antenna is the meteorological satellite; case 3) of PtGain for the transmitting antenna of the railway station; case 4) PtA transmit antenna gain for the train;
Grgain for the receive antenna; the method specifically comprises the following steps: case 1) GrA receive antenna gain for the train; case 2) GrGain for the receiving antenna of the railway station; g in cases 3) and 4)rThe gain of the receiving antenna of the meteorological satellite earth station;
Lpis the propagation path loss; the corresponding values in the four interference cases are different;
ACIR is the isolation provided by each interference situation under different frequency intervals;
the calculation formula is as follows:
Figure FDA0002831815810000011
ACLR represents the adjacent channel leakage power ratio of the offending system; the method specifically comprises the following steps: in the cases of 1) and 2), the ACLR is the adjacent channel leakage power ratio of the meteorological satellite; ACLR in the case of 3) is the adjacent channel leakage power ratio of the railway station; ACLR is the adjacent channel leakage power ratio of the train in the case of 4);
ACS represents the adjacent channel selectivity value of the victim system; the method specifically comprises the following steps: ACS is the adjacent channel selectivity value of the train in case 1); ACS is the adjacent channel selectivity value of the train station in case 2); ACS in the cases of 3) and 4) is the adjacent channel selectivity value of the meteorological satellite earth station;
for the 1) case and the 2) case, when the meteorological satellite generates interference to the ground, the pitch angle of the receiving antenna relative to the maximum gain is different, and the value of the receiving gain is influenced; the method comprises the following specific steps:
Figure FDA0002831815810000021
g (θ) represents a gain with respect to the omni-directional antenna; theta is a pitch angle relative to the maximum gain, and theta is more than or equal to 90 degrees and less than or equal to 90 degrees; g0Represents the maximum gain in the azimuth plane; theta3Is a 3dB beam width in the elevation plane; n represents a parameter that accounts for the side lobe level being above a value predicted by the antenna for improved side lobe performance;
for the case of 3) and the case of 4), when considering interference of a train or a train station to a satellite earth station, the satellite follows an angle deviating from the axial direction
Figure FDA0002831815810000027
The antenna gain in the horizontal direction of the earth station is different, and the specific calculation is as follows:
Figure FDA0002831815810000022
Figure FDA0002831815810000023
Figure FDA0002831815810000024
Figure FDA0002831815810000025
wherein the content of the first and second substances,
Figure FDA0002831815810000028
is the gain of the receiving antenna; gmaxIs the antenna main lobe gain; d is the diameter of the antenna, and lambda is the wavelength;
Figure FDA0002831815810000029
is an angle off axial;
Figure FDA0002831815810000026
a first side-lobe gain;
grouping the four interference situations pairwise, and respectively selecting a static interference threshold value and a dynamic interference evaluation standard;
the four interference situation groups are specifically:
the 1) and 2) cases are taken as a group, and a static interference threshold value is adopted;
the cases of the 3) and the 4) are taken as a group, the dynamic interference evaluation standard is adopted, and the specific parameter is an allowable interference limit value Ilimit(ii) a The method specifically comprises the following steps: i islimit＝N0(Mq-1),M＞Mmin；
N0Is the noise power spectral density; m is the threshold margin of the actual link; q is a margin loss factor; mminIs the minimum value of the threshold margin M;
step four, correcting the propagation path loss value L in four interference conditions by adopting an SPM standard propagation model and using a least square methodp'；
The method comprises the following specific steps:
step 401, for a certain interference situation, giving initial values of each coefficient in an SPM standard propagation model, and calculating a corresponding propagation path loss value L;
L＝(k1+k2×lgf+k3×lghTseff+k4×lgd+k5×lgd×lghTseff+k6×lghRseff)+(k7×Diff+Ccluster)
wherein k is1，k2，k3，k4，k5，k6And k7F is the coefficient of the median propagation path loss, and is the central frequency value; h isTseffIs the effective height value of the transmitting antenna in the interference situation; d is the distance between the transmitting end and the receiving end in the interference situation; h isRseffIs the effective height value of the receiving antenna in the interference situation; diff is the diffraction loss value; cclusterA total terrain correction factor for the interference condition; k is a radical of1，k2，k3，k4，k5，k6And k7Together forming a coefficient matrix K;
step 402, according to the initial value of the actually measured path loss matrix Y, iteration is started to obtain a residual vector delta after k iterationsk；
Y＝(y1 y2...ym)T＝AK+BC
C is a coefficient matrix of a random variable of the propagation loss;
the specific process is as follows:
first, the K-1 th iteration results in Kk-1And Ck-1By AKk＝Y-BCk-1And a matrix solving method of a least square method to obtain a component coefficient Kk；
Then, according to BCk＝Y-AKkAnd a matrix solving method of a least square method to obtain a random component coefficient Ck；
Finally, a residual vector after k iterations is obtained: deltak＝Y-BCk-AKk；
Step 403, determining residual vector deltakWhether convergence is achieved or not, if yes, the correction is finished, and the initial coefficient is successfully corrected; propagation path loss value Lp'The same as the propagation path loss value L; if not, then,continuing iteration until the maximum iteration times are reached, and performing a new round of correction;
step five, according to the corrected propagation path loss value L in the four interference conditionsp'Recalculating received power P for four interference scenariosr'；
Step six, judging the receiving power P in each interference situation which is recalculated one by onerWhether' is greater than a static interference threshold or a dynamic interference evaluation criterion; if so, indicating that the interference exists in the interference situation, otherwise, indicating that the interference does not exist.
2. The interference analysis method for the 450MHz band satellite weather service and railway train dispatching system as claimed in claim 1, wherein said step two is to obtain the required isolation A under each interference situation by using the calculation formula based on the adjacent channel interference rejection ratio when analyzing the adjacent channel interferenceaddiso：
Aaddiso＝Pt+Gt+Gr-Lp-ACIR-Ilimit
IlimitFor the interference threshold value, four interference conditions are determined according to different rules;
the influence of ACIR is not considered in the same frequency condition, and the following formula is adopted for calculation: a. theaddiso＝Pt+Gt+Gr-Lp-Ilimit(ii) a And combining the propagation model to obtain the spatial isolation distance required by coexistence of the transmitting end system and the receiving end system.
CN201710535011.3A 2017-07-03 2017-07-03 Interference analysis method for 450MHz frequency band satellite meteorological service and railway train dispatching system Active CN107395299B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710535011.3A CN107395299B (en) 2017-07-03 2017-07-03 Interference analysis method for 450MHz frequency band satellite meteorological service and railway train dispatching system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710535011.3A CN107395299B (en) 2017-07-03 2017-07-03 Interference analysis method for 450MHz frequency band satellite meteorological service and railway train dispatching system

Publications (2)

Publication Number Publication Date
CN107395299A CN107395299A (en) 2017-11-24
CN107395299B true CN107395299B (en) 2021-01-26

Family

ID=60334235

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710535011.3A Active CN107395299B (en) 2017-07-03 2017-07-03 Interference analysis method for 450MHz frequency band satellite meteorological service and railway train dispatching system

Country Status (1)

Country Link
CN (1) CN107395299B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111294106B (en) * 2018-12-06 2022-06-07 航广卫星网络有限责任公司 Method and device for controlling off-axis equivalent radiation power of satellite communication antenna in motion
CN110290499B (en) * 2019-06-19 2022-08-09 中铁第四勘察设计院集团有限公司 Interference coordination method and device for LTE-R and wireless train dispatching communication system
CN113839727B (en) * 2021-11-24 2022-03-04 中国星网网络创新研究院有限公司 Method, device, equipment and storage medium for determining space isolation range

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102638809A (en) * 2011-02-15 2012-08-15 北京博创讯达通信技术有限责任公司 Simulation method for interference coexistence of mobile communication system
CN103634827A (en) * 2013-11-28 2014-03-12 国家无线电监测中心 Method for determining guard space of specific system under lumped interference of terminals of IMT (International Mobile Telecommunications)

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106411350A (en) * 2010-06-18 2017-02-15 联发科技股份有限公司 System and method for coordinating multiple radio transceivers

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102638809A (en) * 2011-02-15 2012-08-15 北京博创讯达通信技术有限责任公司 Simulation method for interference coexistence of mobile communication system
CN103634827A (en) * 2013-11-28 2014-03-12 国家无线电监测中心 Method for determining guard space of specific system under lumped interference of terminals of IMT (International Mobile Telecommunications)

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
450 MHz 频段卫星气象业务与铁路列调系统干扰共存分析;钱肇钧等;《北京邮电大学学报》;20170228;第40卷(第1期);第1节，图1，图2，第2.1节，第2.3节，第3.3节 *
科学卫星数传链路兼容性分析的对比研究;韩朝晖等;《第十一届卫星通信学术年会论文集》;20151026;第1.2.1节 *
移动通信网络规划中共存干扰和传播模型的研究与仿真;陈瑾;《中国优秀硕士学位论文全文数据库信息科技辑（月刊）》;20131115(第11期);第6.2.2节 *

Also Published As

Publication number Publication date
CN107395299A (en) 2017-11-24

Similar Documents

Publication Publication Date Title
US10601500B2 (en) Systems and methods for beacon detection infrastructures
US10656281B2 (en) Systems and methods for interference detection in shared spectrum channels
CN113131989B (en) Design method for frequency spectrum sharing simulation time parameter of NGSO constellation system
EP2727260B1 (en) Spectrum sharing between an aircraft-based air-to-ground communication system and existing geostationary satellite services
CN107395299B (en) Interference analysis method for 450MHz frequency band satellite meteorological service and railway train dispatching system
US20140126514A1 (en) Method and apparatus for determining network clusters for wireless backhaul networks
CN113067651B (en) Inter-constellation interference detection method for low-orbit satellite system
Tang et al. Frequency sharing between satellite and terrestrial systems in the Ka band: A database approach
CN115118363A (en) NGSO satellite system interference and channel capacity obtaining method based on spatial position probability
CN114221726B (en) Down link co-channel interference characterization method of ka band unmanned aerial vehicle communication system
Yuan et al. Interference analysis of HAPS coexistence on terrestrial mobile networks
Oodo et al. Sharing and compatibility study between fixed service using high altitude platform stations (HAPS) and other services in the 31/28 GHz bands
Wang et al. Coexistence interference analysis of 28 GHz IMT and fixed-satellite service systems
Queiroz et al. New spectrum bands for HAPS: Sharing with fixed-satellite systems
Höyhtyä Frequency sharing between FSS and BSS satellites in the 17.3–18.4 GHz band
Kim et al. Adjacent channel interference from maritime earth station in motion to 5G mobile service
CN113950065B (en) Common-frequency interference suppression method based on protection area and directional antenna
Ahiagbe et al. Methods to evaluate and mitigate the interference from maritime ESIM to other services in 27.5-29.5 GHz band
Menanor et al. Assessment of the interference effects from land earth stations in motion to fixed service stations
El-mohamady et al. Implementation issues for multiple cognitive radio systems sharing satellite Ka-band
Li et al. 0Satellite communication used in the non-geostationary Fixed-satellite service systems and Earth-exploration satellite service (passive) systems
CA3077205C (en) Systems and methods for beacon detection infrastructures
Shi et al. The interference analysis of satellite services in the 8025–8400 MHz frequency band
CN110224739A (en) A kind of LEO Satellite communication link frequency interferences judgment method
Oh et al. Protection of the mobile station from the interference by maritime earth station in motion in the 28 GHz band

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