CN113242065B - Sky wave large-scale MIMO uplink synchronization method using position information - Google Patents

Sky wave large-scale MIMO uplink synchronization method using position information Download PDF

Info

Publication number
CN113242065B
CN113242065B CN202110550483.2A CN202110550483A CN113242065B CN 113242065 B CN113242065 B CN 113242065B CN 202110550483 A CN202110550483 A CN 202110550483A CN 113242065 B CN113242065 B CN 113242065B
Authority
CN
China
Prior art keywords
base station
user
antenna
user side
sky
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
CN202110550483.2A
Other languages
Chinese (zh)
Other versions
CN113242065A (en
Inventor
高西奇
孙榛
王闻今
何思然
石丁
郑奕飞
仲文
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.)
Southeast University
Original Assignee
Southeast University
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 Southeast University filed Critical Southeast University
Priority to CN202110550483.2A priority Critical patent/CN113242065B/en
Publication of CN113242065A publication Critical patent/CN113242065A/en
Application granted granted Critical
Publication of CN113242065B publication Critical patent/CN113242065B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/22—Traffic simulation tools or models
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W56/00—Synchronisation arrangements
    • H04W56/0005—Synchronisation arrangements synchronizing of arrival of multiple uplinks

Landscapes

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

Abstract

The invention discloses a sky wave large-scale MIMO uplink synchronization method using position information, which comprises the following steps: a base station side broadcasts and sends a downlink synchronous signal, and a user side receives the downlink synchronous signal from the base station; the user side calculates and obtains the initial position of the downlink data frame according to the downlink synchronous signal; the user side calculates and obtains the shortest propagation path distance according to the self position information and the base station position information, and obtains the minimum relative time delay of the round-trip transmission of the wireless link of the user according to the shortest propagation path distance; the user side adjusts the sending time of the uplink frame according to the initial position and the downlink relative time delay of the obtained data frame; the base station side feeds back user timing advance information to the user side according to the received uplink synchronization sequence to realize uplink synchronization; the sky wave large-scale MIMO uplink synchronization method utilizing the position information can obviously reduce the system synchronization overhead and improve the frequency spectrum efficiency of a sky wave wireless communication system.

Description

Sky wave large-scale MIMO uplink synchronization method using position information
Technical Field
The invention relates to the technical field of sky wave large-scale MIMO communication, in particular to a sky wave large-scale MIMO uplink synchronization method utilizing position information.
Background
Short-wave communication refers to wireless communication using electromagnetic waves having a frequency of 3-30MHz, i.e., short-wave communication having a wavelength of about 10-100 m. Short-wave communication is widely applied to various fields due to the characteristics of flexibility, easiness in deployment, reliability, long communication distance and the like, plays an irreplaceable role particularly in military departments, and is an important means for military strategy and tactical communication. Sky wave transmission refers to a short-wave communication transmission mode that radio waves are reflected back to a ground receiving point through an ionized layer, and can provide single-hop (<4000km) or multi-hop short-wave communication based on ionized layer reflection. The sky wave transmission has two outstanding advantages, one is that the transmission loss is small, and long-distance communication can be carried out with smaller power; and secondly, the ionosphere as a transmission medium has strong survivability and high transmission reliability.
The large-dimensional characteristic of large-scale MIMO can bring the advantages of improving the utilization rate of frequency spectrum resources, increasing the system capacity and the like, and the OFDM orthogonal frequency division multiplexing technology distributes serial transmission data streams to a plurality of parallel orthogonal subcarriers through serial-parallel conversion, so that intersymbol interference and frequency selective fading can be effectively inhibited. In the actual sky-wave large-scale MIMO wireless communication system, especially uplink, uncorrected time offset will destroy orthogonality, generate inter-symbol interference, inter-channel interference and multi-user interference, and reduce system performance. Because the sky wave transmission distance is long, the uplink synchronization traversal cost is increased, and therefore the uplink synchronization traversal cost of the base station side can be reduced by utilizing the position information to calculate the minimum relative time delay of the round trip transmission of the wireless link of the user and complete the uplink synchronization.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a sky-wave massive MIMO uplink synchronization method using location information, in which a user side calculates a minimum relative time delay for round-trip transmission of a user radio link and completes uplink synchronization by using location information and fully considering a sky-wave transmission mode, an ionosphere height, and a curved surface distance between the user side and a base station side, so as to reduce uplink synchronization traversal cost of the base station side.
In order to achieve the purpose, the invention adopts the following technical scheme:
a sky wave massive MIMO uplink synchronization method using position information is suitable for a sky wave massive MIMO communication system, the system comprises a short wave base station and a plurality of short wave users, and the short wave base station and the short wave users realize massive MIMO communication; the method comprises the following steps:
step S1, the base station side broadcasts and sends the downlink synchronous signal, and the user side receives the downlink synchronous signal from the base station side;
step S2, the user side calculates and obtains the initial position of the downlink data frame according to the downlink synchronous signal;
step S3, the user side calculates and obtains the shortest propagation path distance according to the position information of the user side and the position information of the base station side, and obtains the minimum relative time delay of the round-trip transmission of the wireless link of the user according to the shortest propagation path distance;
step S4, the user side adjusts the sending time of the uplink frame according to the initial position of the downlink data frame calculated in the step S2 and the minimum relative time delay obtained in the step S3;
step S5, the base station side calculates the user timing advance information according to the received uplink synchronization sequence and feeds back the user timing advance information to the user side, and the user side adjusts the uplink frame sending time again by using the user timing advance information to realize uplink synchronization.
Furthermore, in the sky-wave large-scale MIMO communication system, a large-scale antenna array is arranged at the base station side, and a single antenna is arranged at the user side.
Further, the user side calculates and obtains the initial position of the downlink data frame by utilizing the autocorrelation, the cross correlation and the constant amplitude low peak-to-average power ratio characteristic of the downlink synchronization sequence, and completes downlink synchronization.
Further, the location information of the user side and the base station side includes longitude information and latitude information.
Further, the step S3 specifically includes: and the user side solves the approximate shortest propagation path distance or obtains the shortest propagation path distance by tracking by utilizing a ray tracing technology by considering the height of the ionization layer and the longitude and latitude information of two places according to the position information of the user side and the position information of the base station side.
Further, in step S3, when the approximate shortest propagation path distance is solved, the curved surface distance between the base station side and the user side on the earth surface is calculated first, the propagation mode is determined according to the distance, and then the minimum relative delay time of the round-trip transmission of the wireless link of the user is obtained by calculating the solution problem according to the propagation mode, the height of the ionosphere and the curved surface distance
The invention has the beneficial effects that:
1. in the traditional sky wave uplink synchronization, a base station side calculates timing advance through an uplink synchronization signal and sends the timing advance to a user side, and then the user side adjusts the uplink frame sending time to realize uplink synchronization, but the sky wave transmission distance is long, the channel time delay is large, and the cost of traversing and searching an uplink synchronization sequence by the base station is high; for the invention, the user side calculates the minimum relative time delay of the round trip transmission of the wireless link of the user and adjusts the uplink frame sending time by fully considering the sky wave transmission mode, the ionosphere height and the curved surface distance between the user side and the base station side by utilizing the position information, thereby finishing the preliminary uplink synchronization, saving the cost of traversing and searching the uplink synchronization sequence at the base station side, reducing the length of the uplink synchronization sequence and improving the transmission efficiency of the communication system.
2. The algorithm for the minimum relative time delay of the round trip transmission of the wireless link of the user has low calculation complexity and can be well applied to a large-scale MIMO system of the actual sky wave; meanwhile, the method for actually obtaining the minimum relative time delay of the round-trip transmission of the wireless link of the user is not unique, and a plurality of algorithms and ray tracing software can be used, so that the method for obtaining the minimum relative time delay by utilizing the position information has high flexibility.
Drawings
Fig. 1 is a flowchart of a sky-wave massive MIMO uplink synchronization method using location information in embodiment 1.
Fig. 2 is a comparison diagram of the steps of a general uplink synchronization method and the method provided in example 1.
Fig. 3 is a schematic diagram of the spherical distances of the user side and the base station side.
Fig. 4 is a diagram illustrating an uplink timing advance effect.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
Referring to fig. 1 to fig. 4, the present embodiment provides a sky-wave massive MIMO uplink synchronization method using position information, which mainly includes the following steps:
1. a base station side broadcasts and sends a downlink synchronous signal, and a user side receives the downlink synchronous signal from the base station;
2. the user side calculates and obtains the initial position of the downlink data frame according to the downlink synchronous signal;
3. the user side calculates and obtains the shortest propagation path distance according to the self position information and the base station position information, and obtains the minimum relative time delay of the round-trip transmission of the wireless link of the user according to the shortest propagation path distance;
4. the user side adjusts the sending time of the uplink frame according to the initial position and the downlink relative time delay of the obtained data frame;
5. the base station side feeds back the user timing advance information to the user side according to the received uplink synchronous sequence, and the user side adjusts the uplink frame sending time again by using the feedback information to realize uplink synchronization.
Specifically, the embodiments of the present invention are further described in detail below with reference to specific system models.
1. Sky wave large-scale MIMO system configuration and channel model using position information
In the sky wave large-scale MIMO system model, a base station side antenna array comprises more than dozens of antenna units, and each antenna adopts an omnidirectional antenna; the user side antenna is a single antenna, and each user side antenna adopts an omnidirectional antenna.
Considering a long-distance sky wave large-scale MIMO communication system, a linear uniform array with the total number of antennas being M is configured at the base station side, and U single-antenna user terminals are arranged at the user side. The ionosphere is divided into three layers D, E and F, wherein the layers E and F mainly play a role in reflecting electric waves in the transmission process to ensure long-distance transmission, and the layer D plays a role in absorbing to cause signal attenuation. Similar to a general massive MIMO transmission system, the sky wave channel also has characteristics of multipath propagation. In particular, signals typically arrive at the receiving end via multiple paths due to single or multiple reflections from the E or F layers.
Let NcIs the total number of OFDM subcarriers, NgIs the Cyclic Prefix (CP) length, TsFor a systematic sampling interval, a single OFDM symbol duration Tc＝NcTsDuration T of CPg＝NgTc. And order
Figure GDA0003677105180000031
For the analog baseband signal transmitted by the U-th single-antenna user terminal, the received analog baseband signal at the base station side can be expressed as
Figure GDA0003677105180000041
Wherein the content of the first and second substances,
Figure GDA0003677105180000042
is the time-varying uplink channel impulse response vector, z, between the Uth single-antenna user terminal and the base stationul(t) is a noise vector containing M independent complex gaussian white noises having the same power spectral density.
Similarly, order
Figure GDA0003677105180000043
For the analog baseband signal vector transmitted to the U-th single-antenna user terminal in the downlink, the analog baseband signal vector received by the U-th single-antenna user terminal may be represented as:
Figure GDA0003677105180000044
wherein, [ h ]u(t,τ)]TTime-varying downlink channel impulse response vectors for the base station and the U-th single-antenna user terminal, which are the transposes of the uplink channel impulse response vectors in terms of expression,
Figure GDA0003677105180000045
is complex white gaussian noise.In practical applications, only N is generally selectedνThe subcarriers are used for data transmission and are typically chosen close to the center carrier frequency. Suppose that N isνThe sequence number set for transmitting sub-carriers is K ═ {0,1, …, Nν-1}, the remaining Nc-NνThe subcarriers serve as guard subcarriers of the system. Order to
Figure GDA0003677105180000046
For the u-th single-antenna user terminal at
Figure GDA0003677105180000047
The signal transmitted on the k sub-carrier of the symbol.
Then the u-th single-antenna user terminal is at the u-th in case of containing CP
Figure GDA0003677105180000048
The analog baseband signal transmitted on one symbol can be represented as:
Figure GDA0003677105180000049
wherein, Δ f is 1/TcIndicating the subcarrier spacing. Similarly, order
Figure GDA00036771051800000410
Is arranged at the base station side
Figure GDA00036771051800000411
The signal transmitted to the u-th single-antenna user terminal on the k-th sub-carrier of each symbol. Then, in case of containing CP, in the second place
Figure GDA00036771051800000412
The analog baseband signal transmitted on one symbol to the u-th single-antenna user terminal can be represented as:
Figure GDA00036771051800000413
first of base station side
Figure GDA00036771051800000414
The demodulated signal vector for the k-th subcarrier of the symbol can be represented as:
Figure GDA00036771051800000415
wherein the content of the first and second substances,
Figure GDA00036771051800000416
indicating that the u-th single-antenna user terminal and the base station are in the second
Figure GDA00036771051800000417
The uplink channel frequency response vector on the k-th subcarrier of each symbol can be represented as:
Figure GDA00036771051800000418
wherein the content of the first and second substances,
Figure GDA0003677105180000051
to represent
Figure GDA0003677105180000052
The fourier transform of (d).
Figure GDA0003677105180000053
Is subject to
Figure GDA0003677105180000054
A distributed complex gaussian noise vector.
Analogous u th single-antenna user terminal
Figure GDA0003677105180000055
The demodulated signal of the k-th subcarrier of the symbol can be expressed as
Figure GDA0003677105180000056
Wherein, the first and the second end of the pipe are connected with each other,
Figure GDA0003677105180000057
indicating that the base station and the u-th single-antenna user terminal are in the second place
Figure GDA0003677105180000058
The downlink channel frequency response vector of the k-th subcarrier of the symbol,
Figure GDA0003677105180000059
is subject to
Figure GDA00036771051800000510
Distributed complex gaussian noise.
The uplink synchronization process generally refers to a process between a user sending an uplink synchronization signal and a basic connection established between the user and a base station. The significance of realizing uplink synchronization between a user side and a base station side is that because the uplink data transmission in the sky wave large-scale MIMO-OFDM system is based on OFDM modulation, the OFDM modulation requires that the time for the signals of different users to reach the base station is basically the same, otherwise, the interference among subcarriers can be generated. The user side can only realize the synchronization of the user side through the downlink synchronization process, if the user side sends uplink signals according to the downlink synchronization timing, the time difference of the signals of different users reaching the base station can reach 2R due to different distances between different user sides and the base stationcC, wherein RcAnd c is the propagation speed of the electromagnetic wave. By the uplink synchronization method, the time difference of the user signal reaching the base station can be calculated, so that the uplink sending time of the user is adjusted, and preliminary uplink synchronization is realized. FIG. 2 is a comparison between a general uplink synchronization method and a sky-wave massive MIMO uplink synchronization method using position information, in which a user side uses position information to estimate and calculate a timing advance to adjust the uplink frame transmission time, thereby saving the cost of traversing and searching uplink synchronization sequences at a base station side and reducing the uplink synchronization sequencesThe length of the columns improves the transmission efficiency of the system.
2. Calculating and obtaining shortest propagation path distance by using position information
The user side knows its own location information and base station location information, and the location information includes, but is not limited to, longitude and latitude information. And the user side approximates the shortest propagation path distance by considering the height of an ionization layer and latitude and longitude of two places or obtains the shortest propagation path distance by tracing by utilizing a ray tracing technology according to the known self position information and the base station position information.
User position P known by user side1And base station position P2In which position Pi(i-1, 2) determining the position, i.e. the user position P, from the latitude and longitude information of the position1Has a longitude and latitude of (alpha)1,β1) Base station position P2Has a longitude and latitude of (alpha)2,β2) In which α isi(i-1, 2) is position PiLongitude, beta ofi(i is 1,2) is a position PiThe latitude of (c). For the sake of calculation, the earth is assumed to be a perfect sphere with a radius equal to 6378.137km, which is the average radius R of the earth. According to the definition of longitude and latitude, the north and the south are respectively divided into 90 degrees from the equator, which are called north latitude and south latitude, and the north latitude takes a positive value and the south latitude takes a negative value. According to the reference of 0 degree of longitude, the east longitude takes positive value, the west longitude takes negative value, namely alphai∈(-180,180],βi∈[-90,90]. Fig. 3 is a schematic diagram of the spherical distances of the user side and the base station side, and the spherical distance S between the user side and the base station side can be expressed by solving the geodetic problem as follows:
Figure GDA0003677105180000061
because possible propagation modes of sky-wave communication are different according to different propagation distances, the shortest propagation path distance is considered, the propagation distance is considered to be within the range of 0-2000km, and the sky-wave transmission is carried out in a propagation mode of once passing through E-layer ionosphere reflection; within the range of 2000-4000km of propagation distance, the sky wave transmission is carried out in a propagation mode of once passing through the F-layer ionosphere reflection; propagation distance of 400In the range of 0-8000km, the sky wave transmission is carried out twice through a propagation mode of F-layer ionospheric reflection. Let E layer ionosphere reflection height hE100km, ionospheric reflection height h of F layerF300km, the shortest propagation path distance S between the user side and the base station sideSWCan be expressed as:
Figure GDA0003677105180000062
3. uplink timing advance
According to the shortest path propagation distance S obtained by calculationSWThe user can obtain the shortest time difference theta of the user signal to the base station as SSWAnd c, adjusting the uplink sending time of the user to be 2 theta earlier than the original uplink sending time, thereby realizing that the time of the signals of a plurality of users reaching the base station is basically the same, saving the cost of traversing and searching the uplink synchronous sequence at the base station side, calculating the timing advance of the user and feeding the timing advance back to the user at the base station side according to the uplink synchronous sequence, and updating the uplink frame sending time by the user according to the received timing advance of the user to realize uplink synchronization. Fig. 4 is a schematic diagram illustrating an effect of uplink timing advance, where multiple users make the time for receiving signals of the multiple users by the base station side substantially the same through the uplink timing advance, so that the cost of traversing and searching an uplink synchronization sequence by the base station side is saved, uplink synchronization is achieved, and interference between subcarriers is avoided.
The invention is not described in detail, but is well known to those skilled in the art. The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims (5)

1. An sky-wave massive MIMO uplink synchronization method using position information is characterized in that the method is suitable for an sky-wave massive MIMO communication system, the system comprises a short wave base station and a plurality of short wave users, and the short wave base station and the short wave users realize massive MIMO communication;
the method comprises the following steps:
step S1, the base station side broadcasts and sends the downlink synchronous signal, and the user side receives the downlink synchronous signal from the base station side;
step S2, the user side calculates and obtains the initial position of the downlink data frame according to the downlink synchronous signal;
the step S2 is based on a sky-wave massive MIMO system and a channel model using location information, and specifically includes:
in the sky wave large-scale MIMO system model, a base station side antenna array comprises more than dozens of antenna units, and each antenna adopts an omnidirectional antenna; the user side antenna is a single antenna, and each user side antenna adopts an omnidirectional antenna;
considering a long-distance sky wave large-scale MIMO communication system, a linear uniform array with the total number of antennas being M is configured on a base station side, U single-antenna user terminals are arranged on a user side, and an ionized layer is divided into three layers D, E and F, wherein the E and F mainly play a role in reflecting electric waves in a transmission process to ensure long-distance transmission, and the D layer plays a role in absorbing to cause signal attenuation;
let NcIs the total number of OFDM sub-carriers, NgIs a cyclic prefix length, TsFor a systematic sampling interval, a single OFDM symbol duration Tc＝NcTsDuration T of CPg＝NgTcAnd make an order
Figure FDA0003631470970000011
For the analog baseband signal transmitted by the U-th single-antenna user terminal, the analog baseband signal received by the base station side is represented as:
Figure FDA0003631470970000012
wherein the content of the first and second substances,
Figure FDA0003631470970000013
is the time-varying uplink channel impulse response vector, z, between the Uth single-antenna user terminal and the base stationul(t) is a noise vector containing M independent complex gaussian white noises having the same power spectral density;
order to
Figure FDA0003631470970000014
For the analog baseband signal vector transmitted to the U-th single-antenna user terminal in the downlink, the analog baseband signal vector received by the U-th single-antenna user terminal is expressed as:
Figure FDA0003631470970000015
wherein [ h ]u(t,τ)]TTime-varying downlink channel impulse response vectors for the base station and the Uth single-antenna user terminal, which are the transpose of the uplink channel impulse response vector in terms of expression,
Figure FDA0003631470970000021
complex white gaussian noise;
selecting only NνSub-carriers are used for data transmission and sub-carriers near the center carrier frequency are selected, assuming that N is assignedνThe sequence number set for transmitting sub-carriers is K ═ {0,1, …, Nν-1}, the remaining Nc-NνThe sub-carriers are used as guard sub-carriers for the system, order
Figure FDA0003631470970000022
A signal transmitted on a kth subcarrier of a l symbol for a u single-antenna user terminal;
then, in the case of containing CP, the analog baseband signal transmitted by the u-th single-antenna user terminal on the l-th symbol is represented as:
Figure FDA0003631470970000023
wherein, Δ f is 1/TcRepresents a subcarrier spacing;
order to
Figure FDA0003631470970000024
For the signal transmitted to the u-th single-antenna user terminal on the kth subcarrier of the l-th symbol on the base station side, the analog baseband signal transmitted to the u-th single-antenna user terminal on the l-th symbol in the case of including the CP is represented as:
Figure FDA0003631470970000025
the demodulation signal vector of the kth subcarrier of the ith symbol on the base station side is expressed as:
Figure FDA0003631470970000026
wherein the content of the first and second substances,
Figure FDA0003631470970000027
the uplink channel frequency response vector of the u-th single-antenna user terminal and the base station on the k-th subcarrier of the l-th symbol is represented as:
Figure FDA0003631470970000028
wherein the content of the first and second substances,
Figure FDA0003631470970000029
to represent
Figure FDA00036314709700000210
The fourier transform of (a) the signal,
Figure FDA00036314709700000211
is subject to
Figure FDA00036314709700000212
A distributed complex gaussian noise vector;
the demodulated signal of the k sub-carrier of the ith symbol of the u single-antenna user terminal is represented as
Figure FDA0003631470970000031
Wherein the content of the first and second substances,
Figure FDA0003631470970000032
representing the downlink channel frequency response vector of the base station and the u-th single-antenna user terminal at the k-th subcarrier of the l-th symbol,
Figure FDA0003631470970000033
is subject to
Figure FDA0003631470970000034
Distributed complex gaussian noise;
step S3, the user side calculates and obtains the shortest propagation path distance according to the position information of the user side and the position information of the base station side, and obtains the minimum relative time delay of the round-trip transmission of the wireless link of the user according to the shortest propagation path distance;
the user side calculates and obtains the shortest propagation path distance according to the position information of the user side and the position information of the base station side, and the method specifically comprises the following steps:
user side known user position P1And base station position P2In which position Pi(i-1, 2) determining the position, i.e. the user position P, from the latitude and longitude information of the position1Has a longitude and latitude of (alpha)1,β1) Base station position P2Has a longitude and latitude of (alpha)2,β2) In which α isi(i-1, 2) is a positionPiLongitude, beta ofi(i is 1,2) is a position PiThe latitude of (d);
the earth is assumed to be a perfect sphere, and the radius of the sphere is 6378.137km which is the average radius R of the earth;
positive north latitude, negative south latitude, positive east longitude and negative west longitude, alphai∈(-180,180],βi∈[-90,90]；
The spherical distance S between the user side and the base station side is known by solving the geodetic problem and is expressed as:
Figure FDA0003631470970000035
because the propagation modes of sky-wave communication are different according to the difference of the propagation distances, the shortest propagation path distance is considered, the propagation distance is considered to be within the range of 0-2000km, and the sky-wave transmission is carried out in a propagation mode of once passing through E-layer ionosphere reflection; within the range of 2000-4000km of propagation distance, the sky wave transmission is carried out in a propagation mode of once passing through the F-layer ionosphere reflection; the propagation distance is 4000-8000km, the sky wave transmission is performed twice through the F layer ionosphere reflection, so that the E layer ionosphere reflection height hE100km, ionospheric reflection height h of F layerF300km, the shortest propagation path distance S between the user side and the base station sideSWExpressed as:
Figure FDA0003631470970000041
step S4, the user side adjusts the sending time of the uplink frame according to the initial position of the downlink data frame calculated in step S2 and the minimum relative time delay obtained in step S3;
and step S5, the base station side calculates the user timing advance information according to the received uplink synchronization sequence and feeds the user timing advance information back to the user side, and the user side utilizes the user timing advance information to adjust the uplink frame sending time again to realize uplink synchronization.
2. The method of claim 1, wherein the user side calculates the starting position of the downlink data frame by using autocorrelation, cross-correlation and constant amplitude low peak-to-average power ratio of the downlink synchronization sequence to complete downlink synchronization.
3. The sky-wave massive MIMO uplink synchronization method using location information as claimed in claim 2, wherein the location information of the user side and the base station side includes longitude information and latitude information.
4. The skywave massive MIMO uplink synchronization method according to claim 3, wherein the step S3 specifically includes: and the user side solves the approximate shortest propagation path distance or obtains the shortest propagation path distance by tracking by utilizing a ray tracing technology by considering the height of the ionization layer and the longitude and latitude information of two places according to the position information of the user side and the position information of the base station side.
5. The sky-wave massive MIMO uplink synchronization method using position information as claimed in claim 4, wherein in the step S3, when the approximate shortest propagation path distance is solved, the curved surface distance between the earth surface and the base station side and the user side is calculated first, and the propagation mode is determined according to the distance, and then the minimum relative time delay of the round trip transmission of the user wireless link is obtained by calculating the ground problem according to the propagation mode, the height of the ionosphere and the curved surface distance.
CN202110550483.2A 2021-05-20 2021-05-20 Sky wave large-scale MIMO uplink synchronization method using position information Active CN113242065B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110550483.2A CN113242065B (en) 2021-05-20 2021-05-20 Sky wave large-scale MIMO uplink synchronization method using position information

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110550483.2A CN113242065B (en) 2021-05-20 2021-05-20 Sky wave large-scale MIMO uplink synchronization method using position information

Publications (2)

Publication Number Publication Date
CN113242065A CN113242065A (en) 2021-08-10
CN113242065B true CN113242065B (en) 2022-07-19

Family

ID=77137882

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110550483.2A Active CN113242065B (en) 2021-05-20 2021-05-20 Sky wave large-scale MIMO uplink synchronization method using position information

Country Status (1)

Country Link
CN (1) CN113242065B (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103344951A (en) * 2013-06-25 2013-10-09 电子科技大学 Method for selecting signal transmitting frequency of sky wave MIMO-OTH radar
CN108363037A (en) * 2018-02-27 2018-08-03 武汉大学 A kind of one step positioning mode of shortwave remote radiation source based on wide-area distribution type single antenna reception

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105554870A (en) * 2015-12-21 2016-05-04 海能达通信股份有限公司 Uplink synchronization method and mobile terminal
CN109792268B (en) * 2016-08-09 2021-09-21 瑞典爱立信有限公司 System and method for adaptive initial synchronization beam scanning
CN108989251A (en) * 2018-07-20 2018-12-11 江苏卓达信息科技有限公司 A kind of communication system based on shortwave narrowband waveform
CN110113285B (en) * 2019-05-05 2021-06-11 东南大学 OFDM system closed-loop time-frequency synchronization method and device
US11317427B2 (en) * 2019-11-11 2022-04-26 Trellisware Technologies, Inc. Network-enabled connectivity for disadvantaged communication links
CN112511201B (en) * 2020-11-19 2021-10-26 东南大学 Sky wave large-scale MIMO communication method, model and system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103344951A (en) * 2013-06-25 2013-10-09 电子科技大学 Method for selecting signal transmitting frequency of sky wave MIMO-OTH radar
CN108363037A (en) * 2018-02-27 2018-08-03 武汉大学 A kind of one step positioning mode of shortwave remote radiation source based on wide-area distribution type single antenna reception

Also Published As

Publication number Publication date
CN113242065A (en) 2021-08-10

Similar Documents

Publication Publication Date Title
CN110830097B (en) Active and passive reciprocal symbiotic transmission communication system based on reflecting surface
CN110518961B (en) Large-scale MIMO satellite mobile communication method and system
US6362781B1 (en) Method and device for adaptive antenna combining weights
US6826240B1 (en) Method and device for multi-user channel estimation
US7177369B2 (en) Multipath communication methods and apparatuses
CN1838656B (en) Method and apparatus for uplink carrier frequency synchronization and antenna weight vector estimation
US6765969B1 (en) Method and device for multi-user channel estimation
US6504506B1 (en) Method and device for fixed in time adaptive antenna combining weights
EP1671396B1 (en) Communication system and method for channel estimation and beamforming using a multi-element array antenna
CN101083647B (en) Method for realizing synchronization in multi-input multi-output OFDM system
CN101523736B (en) Mobile assisted downlink beamforming with antenna weight feedback
US6647078B1 (en) Method and device for multi-user frequency-domain channel estimation based on gradient optimization techniques
CN1988526B (en) Synchronizing method for multiple input multiple output orthogonal frequency division multiplex radio system
CN112511201B (en) Sky wave large-scale MIMO communication method, model and system
US8520778B2 (en) System and method for estimation and correction of carrier frequency offset in MIMO-OFDM based wireless communications systems
CN102710309B (en) Be applicable to the synchronizing signal launching technique of large-scale antenna array
EP1714454A1 (en) Multicarrier receivers and methods for separating transmitted signals in a multiple antenna system
CN101411151B (en) Radio reception device, radio transmission device, radio base station, reception method, and transmission method
CN101330316B (en) Time synchronization method and device for up link of wireless communication system
WO2016066030A1 (en) System and method for wireless communication using space-time block code encoding
CN115065432A (en) Sky wave large-scale MIMO triple beam base channel modeling and channel information acquisition
CN105516031A (en) Channel estimation and channel equalization method of fast frequency hopping system
CN100568766C (en) The apparatus and method of received signal in the mobile communication system of using adaptive antenna array scheme
CN113242065B (en) Sky wave large-scale MIMO uplink synchronization method using position information
KR100243106B1 (en) The structure of mc-cdma receiver using antenna array and receiving method

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