CN-122026946-A - Multichannel frequency hopping communication method based on underwater unmanned vehicle broadside array

CN122026946ACN 122026946 ACN122026946 ACN 122026946ACN-122026946-A

Abstract

A multichannel frequency hopping communication method based on an underwater unmanned vehicle broadside array aims to solve the problems that noise of each array element of the broadside array is related and inconsistent in strength and communication performance of the broadside array is reduced due to too strong platform self-noise of the underwater unmanned vehicle. Performing port and starboard deblurring according to the signal energy of the array elements in the broadside array to determine a signal incidence side, estimating the arrival direction of the array elements on the signal incidence side, obtaining the delay difference of adjacent array element signals, compensating the array element signals, sequentially weighting and merging a plurality of array elements with compensated delay differences to obtain a plurality of merging results, and selecting the number of the array elements which are finally needed to be merged to form an array element subset. And solving the output signal-to-noise ratio of the array element subset and the weighting coefficient of each array element to obtain a unique weighting coefficient, combining all array element signals in the array element subset, calculating the signal arrival time in the combined signal, carrying out Doppler estimation compensation, and calculating the compensated combined signal by using an iterative receiver to obtain original bit information.

Inventors

ZHANG DIANLUN
WANG LIANJIE
HONG XIAOPING
SUN DAJUN
ZHANG JUCHENG
ZHENG CUIE
LI HAIPENG
HAN YUNFENG

Assignees

哈尔滨工程大学

Dates

Publication Date: 20260512
Application Date: 20260214

Claims (10)

1. A multichannel frequency hopping communication method based on an underwater unmanned vehicle side array is characterized by comprising the following steps: S1, a receiving end of an unmanned aircraft receives channel signals collected by a port and starboard of a broadside array of the unmanned aircraft, and a rough estimation time for a communication signal in each channel signal to reach the receiving end is obtained by adopting a matching correlation method; s2, calculating the signal energy of each array element in the broadside array according to the rough estimation time when each communication signal reaches the receiving end, and performing port-starboard deblurring according to the signal energy of each array element to determine a signal incident side; s3, estimating the direction of arrival of the array element at the signal incidence side based on the S2, and obtaining the delay difference of the channel signals received by the adjacent array element at the signal incidence side; S4, obtaining a noise power change trend according to the signal energy of each array element in the signal incidence side in the S2, sequentially carrying out delay difference compensation on each array element in the signal incidence side according to the noise power change trend and the delay difference of the adjacent array element received channel signals obtained in the S3, and sequentially weighting and combining a plurality of array elements after compensating the delay differences to obtain a plurality of combining results; Calculating the output signal-to-noise ratio of each combination result, setting an output signal-to-noise ratio threshold value, and taking the number of array elements in the combination result corresponding to the first output signal-to-noise ratio greater than the output signal-to-noise ratio threshold value as the number of array elements to be finally combined; starting with the array element corresponding to the minimum value in the noise power variation trend, sequentially selecting the number of the array elements to be combined finally to form an array element subset; S5, solving a weight coefficient of each array element in the array element subset and an output signal to noise ratio of the array element subset, solving a first-order partial derivative of the weight coefficient of any array element by utilizing the output signal to noise ratio, simplifying a first-order partial derivative formula into a homogeneous linear equation, and restraining the homogeneous linear equation to obtain a non-homogeneous linear square array equation set, and solving a unique weight coefficient according to the non-homogeneous linear square array equation set; S6, combining the channel signals of all the array elements in the array element subset according to the delay difference of the channel signals received by the adjacent array elements in the signal incidence side obtained in the S3, the array element subset obtained in the S4 and the unique weighting coefficient obtained in the S5 to obtain a combined signal; S7, calculating the time of the communication signal in the combined signal reaching the receiving end by using a matching correlation method, and carrying out Doppler estimation compensation to obtain a compensated combined signal; s8, resolving the compensated combined signal by adopting an iterative receiver to obtain original bit information.
2. The multichannel frequency hopping communication method based on the side array of the underwater unmanned vehicle according to claim 1, wherein the specific process of S2 is as follows: and calculating the signal energy of each array element in the broadside array according to the rough estimation time when each communication signal reaches the receiving end, comparing the signal energy of two array elements opposite to each other in the port and starboard until all the array elements in the port and starboard are compared, and taking the side with the large total signal energy as the signal incidence side.
3. The multichannel frequency hopping communication method based on the side array of the underwater unmanned vehicle according to claim 2, wherein the specific process of S3 is as follows: S31, calculating according to the receiving sampling rate and the distance between adjacent array elements to obtain the direction of arrival of each array element, and expressing the direction of arrival of all the array elements as a one-dimensional vector The outputs of the array on the signal incidence side in different directions of arrival are as follows: (1) (2) Wherein, the To compensate for the time-delay-difference signal-incident-side array-combined signal, Is the number of the array elements on one side, , In order to be able to distinguish the direction of arrival, , To compensate for the delay difference The channel signals received by the array elements, Is the direction of arrival The delay difference of the channel signals received by adjacent array elements, Is the speed of sound, Is the distance between adjacent array elements; S32, calculating signal incidence side array combined signal power in different directions of arrival, and obtaining an estimated value of the direction of arrival according to the signal incidence side array combined signal power: (3) (4) Wherein, the Is the direction of arrival The corresponding signal-incident side array combines the signal powers, In order to receive the channel signal duration, Is the estimated value of the direction of arrival; S33, obtaining the time delay difference of the channel signals received by the adjacent array elements on the signal incidence side according to the arrival direction estimation value : (5)。
4. The multichannel frequency hopping communication method based on the side array of the underwater unmanned vehicle according to claim 3, wherein the specific process of S4 is as follows: S41, obtaining signal energy of each array element in the signal incidence side according to the S2, obtaining noise power change trend according to the signal energy of each array element, starting from an array element corresponding to the minimum value in the noise power change trend, sequentially performing delay difference compensation on each array element in the signal incidence side by using the delay difference of the channel signals received by the adjacent array elements obtained in the S3, and sequentially weighting and combining Obtaining a plurality of merging results by compensating array elements with time delay differences; s42, calculating the output signal-to-noise ratio of each combination result ; S43, setting the threshold value of the output signal to noise ratio The first is larger than the threshold value of the output signal to noise ratio The number of the array elements in the combination result corresponding to the output signal-to-noise ratio is used as the number of the array elements which are finally required to be combined ; S44, starting with the array element corresponding to the minimum value in the noise power variation trend, and sequentially selecting The array elements form a subset of array elements.
5. The multi-channel frequency hopping communication method based on the side array of the underwater unmanned vehicle according to claim 4, wherein the specific process of S41 is as follows: assume that the signal incident side comprises 12 array elements, i.e Obtaining signal energy of each array element according to S2, obtaining noise power change trend according to the signal energy of 12 array elements, assuming that the noise power change trend is a linear descending trend, and the array element corresponding to the minimum value in the noise power change trend is the 12 th array element, starting from the 12 th array element, performing delay difference compensation on each array element sequentially from back to front by using the delay difference of the adjacent array element obtained by S3 to receive channel signals, and then according to the following steps Value weighted combining in turn The array elements after the compensation of the time delay difference, : When (when) When the method is used, only the array elements after the 12 th compensation delay difference are taken as a group; When (when) When the method is used, only the array elements after the 12 th and 11 th compensation delay differences are taken as a group; When (when) When the method is used, only the array elements after the 12 th, 11 th and 10 th compensation delay differences are taken as a group; and so on, according to Each is obtained separately And merging results corresponding to the values.
6. The multi-channel frequency hopping communication method based on the side array of the unmanned underwater vehicle as set forth in claim 5, wherein the S43 sets an output signal-to-noise ratio threshold value The specific process of (2) is as follows: (6) Wherein, the For the maximum output signal-to-noise ratio obtained at S42, Is an arbitrary positive number.
7. The multi-channel frequency hopping communication method based on the side array of the unmanned underwater vehicle as set forth in claim 6, wherein the number of array elements to be finally combined in S43 Expressed as: (7)。
8. the multichannel frequency hopping communication method based on the side array of the underwater unmanned vehicle according to claim 7, wherein the specific process of S5 is as follows: s51, solving a weighting coefficient of each array element in the array element subset by using a maximum proportion combination mode; S52, assuming output signal-to-noise ratio of array element subset under the additive Gaussian white noise channel The method comprises the following steps: (8) Wherein, the Is the first The weighting coefficients of the individual array elements are, , Is the first The channel fading coefficients of the individual array elements, For the signal power of each array element, Is the sum of the self-power spectral densities of all the array element noises in the array element subset, Contributing terms for cross power spectral density of noise among all array elements in the array element subset; S53, utilizing the output signal to noise ratio of the array element subset Solving a first-order bias guide for the weighting coefficient of any array element, and setting the bias guide to be 0 to obtain: (9) Wherein, the Is the first The channel fading coefficients of the individual array elements, Is the first The weighting coefficients of the individual array elements are, Is the first The noise power of the individual array elements is, Is the first Array elements and the first Correlation of individual array element noise; S54, based on formula (9): (10) Wherein, the For the weighting coefficients of two array elements taken from the subset of array elements, , Is the first The channel fading coefficients of the individual array elements, Is the first The channel fading coefficients of the individual array elements, Is the first The noise power of the individual array elements is, Is the first The noise power of the individual array elements is, Is the first Array elements and the first The correlation of the noise of the individual array elements, Is the first Array elements and the first Correlation of individual array element noise; Reducing equation (10) to a homogeneous linear equation: (11) Wherein, the Is the first Array elements and the first Correlation of individual array element noise; the following constraints are added to formula (11): (12) Wherein, the Is any array element in the array element subset, , Is the first Weighting coefficients of the array elements; the combination of the two (11) and (12) to obtain a non-homogeneous linear square matrix equation set, and the unique weighting coefficient is obtained according to the non-homogeneous linear square matrix equation set 。
9. The multi-channel frequency hopping communication method based on the side array of the unmanned underwater vehicle as set forth in claim 8, wherein the sum of the self-power spectral densities of all the array element noises in the subset of the array elements in S52 And the cross-power spectral density of noise between all elements in the subset of elements The expressions of (2) are respectively: (13) (14) Wherein, the Is the first Array elements and the first The correlation coefficient of the noise of each array element, Is the first The weighting coefficients of the individual array elements are, Is the first The noise power of the individual array elements is, Is the first Noise power of individual array elements.
10. The multi-channel frequency hopping communication method based on the side array of the underwater unmanned vehicle according to claim 1, wherein the expression of S6 is: (15) Wherein, the In order to combine the signals, To compensate for the delay difference And channel signals received by each array element.

Description

Multichannel frequency hopping communication method based on underwater unmanned vehicle broadside array Technical Field The invention relates to the field of underwater acoustic communication, in particular to a multichannel frequency hopping communication method based on an underwater unmanned aircraft broadside array. Background With the continued exploration and development of the ocean, unmanned underwater vehicles (Unmanned Underwater Vehicle, UUV) are receiving widespread attention. UUVs can provide information transfer services for various underwater, water-surface and air platforms by carrying communications equipment. The wide application of underwater vehicles puts higher demands on the communication capability of the underwater vehicles, however, the UUV platform self-noise covers the common underwater acoustic communication frequency band, and is an important consideration for the design of the communication system of the underwater vehicles. Frequency hopping multi-system frequency shift keying (Frequency Hopping-Multiple Frequency SHIFT KEYING, FH-MFSK), which is called frequency hopping communication for short, is widely applied to UUV communication because of strong anti-interference and anti-noise capability. In order to further improve the communication capability, the communication research is gradually developed to the array receiving direction, and the multichannel receiving processing can effectively improve the communication reliability. For a UUV platform with limited space and small size, communication is realized by using a broadside detection array, so that loads brought by other arrays can be effectively avoided. Chinese patent CN119854072a discloses a method for processing a single carrier communication frequency domain array based on equal gain combination, but UUV self-noise causes significant differences in noise intensity of each array element of the broadside array, and equal gain combination cannot obtain an optimal output signal-to-noise ratio. The Chinese patent CN120151164A discloses a diversity combining method in the technical field of wireless communication, calculates a weighting coefficient by utilizing a received signal-to-noise ratio, and overcomes the defect that diversity gain is reduced when the signal-to-noise ratio difference is large in the traditional method. However, UUV platform self-noise causes noise of each array element of the broadside array to have certain correlation, and the performance of the weight coefficient calculated by using the signal-to-noise ratio is poor in broadside array communication. Therefore, the invention discloses a communication signal processing method suitable for the side array of the underwater unmanned aircraft. Disclosure of Invention The invention aims to solve the problem that the noise of each array element of a broadside array is related and strength is inconsistent due to the fact that the self-noise of a platform of an underwater unmanned aircraft is too strong, and the communication performance of the broadside array is reduced, and further provides a multichannel frequency hopping communication method based on the broadside array of the underwater unmanned aircraft. The technical scheme adopted by the invention is as follows: it comprises the following steps: S1, a receiving end of an unmanned aircraft receives channel signals collected by a port and starboard of a broadside array of the unmanned aircraft, and a rough estimation time for a communication signal in each channel signal to reach the receiving end is obtained by adopting a matching correlation method; s2, calculating the signal energy of each array element in the broadside array according to the rough estimation time when each communication signal reaches the receiving end, and performing port-starboard deblurring according to the signal energy of each array element to determine a signal incident side; s3, estimating the direction of arrival of the array element at the signal incidence side based on the S2, and obtaining the delay difference of the channel signals received by the adjacent array element at the signal incidence side; S4, obtaining a noise power change trend according to the signal energy of each array element in the signal incidence side in the S2, sequentially carrying out delay difference compensation on each array element in the signal incidence side according to the noise power change trend and the delay difference of the adjacent array element received channel signals obtained in the S3, and sequentially weighting and combining a plurality of array elements after compensating the delay differences to obtain a plurality of combining results; Calculating the output signal-to-noise ratio of each combination result, setting an output signal-to-noise ratio threshold value, and taking the number of array elements in the combination result corresponding to the first output signal-to-noise ratio greater than the output signal-to-noise rat