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In the dynamic point-to-point communication, to track and aim at antenna fast and accurately is the guarantee of high quality communication signal. In order to solve the problem of antenna alignment, we used the least square method (LSM) to fit the optimal level signal value (LSV) point which is based on coordinate coarse tracking alignment and matrix scanning strategy to find the LSV in this paper. Antenna is driven by two-dimensional turntable (azimuth and elevation angle (AE)): the two-dimensional turntable is decomposed into two independent one-dimensional turntables, and the LSV in AE direction are obtained by scanning, respectively. The optimal LSV point of two-dimensional turntable can be find by combing optimal LSV point of two independent one-dimensional turntables. The method has the advantages of high precision and easy implementation and can meet the requirement of fast and accurately alignment in dynamic point-to-point communication antenna engineering.

Directional antennas are commonly used for point-to-point communication in microwaves to reduce transmission and receiving power. The basic principle of alignment is that both stations can receive and transmit microwave signal. However, it is difficult to align the communication antenna at a long distance with the narrow beam angle of antenna, especially when there is relative motion at both stations. At present, the coordinate tracking control method (TCM)[

In this paper, the problem of antenna tracking and alignment is analyzed under the movement of directional antenna for two stations; the solution and implementation scheme are proposed. The engineering method of antenna alignment is based on the known geographic latitude and longitude of both stations of communication, which is instructive for engineering realization of microwave communication antenna alignment.

Both sides of the communication (two stations) obtain the local longitude, latitude, and altitude data through GPS [

The matrix scan is shown in Figure

Matrix scan for finding the optimal LSV.

Know the latitude and longitude of both stations communication platform, use the coordinate TCM for coarse alignment of the antenna, and then use the signal tracking method for high-precision secondary alignment, designers generally to monitor the strength of the receive signal by detecting the amplitude of the intermediate frequency signal. In this paper, the microwave signal theory to measure the strength of the receive LSV is written in Friis [

In (

It can be known from (

The LSM is a form of mathematical regression analysis that finds the line of optimal fit for a dataset, providing a visual demonstration of the relationship between the data points. We used the LSM fitting large amounts of data points by linear polynomial in the paper in which the method has proved that the distance errors between the fitted curve and the data point are the smallest [

Defining the alignment center of antenna as the optimal LSV point, the LSV can be expressed as a polynomial:

Equation (

If alignment center the antenna is in the position of

According to the conventional polynomial, (

So we need to solve the value of a_{2} / a_{1} / a_{0}, which according to (

According to the LSM principle

Here

According to (

Equation (

In this paper, the AE direction is scanned within a certain errors range, respectively, fitting the optimal LSV of AE by LSM. Figure

Fitting diagram of theoretical and noise measurement value.

The theoretical center value of the antenna is set to 1deg in Figure

However, there may be some coincidence that one or several times optimal values are close to theoretical value by fitting of LSM. Therefore, our paper analyzed the value that the optimal points of 20 times and then compared these values with theoretical value. The light blue line is angle of the theoretical center value of the antenna, and the 20 red dots are the different optimal value by multiplex fitting of LSM in Figure

Analysis of actual measurements and theoretical measurements after multiple measurements.

Because of the noise and interference in the dynamic point-to-point communication it is difficult to align the communication antenna at a long distance with the narrow beam angle of antenna. In this paper, a method based on coordinate tracking coarse alignment and matrix scanning to find the level is proposed; the LSM fitting is used to find the optimal LSV. Antenna is driven by two-dimensional turntable; the two-dimensional turntable is decomposed into two independent one-dimensional turntables, and the optimal LSV of AE direction is obtained, respectively. The simulation result shows that obtaining the optimal value by fitting of LSM is very reliable method. The method of LSM fitting can meet the requirement of fast alignment in antenna automatic tracking when two stations are stationary or in fast motion.

The data used to support the findings of this study are available from the corresponding author upon request.

The authors declare that they have no conflicts of interest.