A Ku-band Starlink terminal uplink signal detection method

Abstract

The present invention discloses a Ku-band Starlink terminal uplink signal detection method, comprising the following steps: Step 1, a broadband receiver sets a signal frequency and collects signal IQ data, the sampling rate is fs, and the complex signal sample is recorded as; Step 2, the complex signal sample is divided into packets for autocorrelation operation, and the number of samples L in each packet should satisfy:; wherein, is the effective length of the Starlink terminal uplink signal synchronization frame; Step 3, a spectrum peak search is performed at a specified index,, where is an integer and 1, the maximum value of is related to the length of, that is, it satisfies; Step 4, if a spectrum peak is detected at, it is considered that a Starlink terminal uplink signal is detected, and the detection result is reported; Step 5, if no spectrum peak is detected, return to step 2 to perform detection and judgment on the next packet of data.

Description

Technical Field

[0001] The present invention relates to the field of radio monitoring technology, and more specifically to a Ku-band Starlink terminal uplink signal detection method. Background Art

[0002] Currently, Internet satellite constellations are developing rapidly, especially Starlink, which has opened communication services in many regions. Since its communication relies on inter-satellite link transmission, it is not constrained by the ground and out of supervision. Satellite user terminals are small in size, have narrow uplink beams, and are difficult to detect, which poses a serious threat to information security.

[0003] Currently, satellite terminal supervision is usually achieved by using drones equipped with monitoring equipment. However, since the Starlink satellite terminal uses a phased array antenna with a very narrow main lobe wave velocity, the drone monitoring platform usually receives sidelobe signals, which are weak and burst communications. When the distance is far, the signal may be submerged in noise, making it difficult to detect the signal by conventional means. Summary of the invention

[0004] The purpose of the present invention is to provide a Ku-band Starlink terminal uplink signal detection method, in order to solve the technical problems existing in the background technology.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A Ku-band Starlink terminal uplink signal detection method comprises the following steps:

[0007] Step 1: The broadband receiver sets the signal frequency and collects the signal IQ data. The sampling rate is fs, and the complex signal sample is recorded as ;

[0008] Step 2: Transform the complex signal samples The autocorrelation operation is performed in packages, and the number of samples L in each package should satisfy:

[0009] ;

[0010] in, It is the effective length of the synchronization frame of the uplink signal of the Starlink terminal;

[0011] The autocorrelation formula is as follows:

[0012]

[0013] Step 3: To specify the index Perform peak search at ,here is an integer and 1, The maximum value of The length of ;

[0014] Step 4: If If a spectrum peak is detected at , it is considered that the Starlink terminal uplink signal is detected and the detection result is reported;

[0015] Step 5: If no spectrum peak is detected, return to step 2 to detect and judge the next packet of data.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention detects the Starlink terminal uplink signal by means of autocorrelation based on the prior knowledge of the Starlink terminal uplink signal. The proposed method is suitable for FPGA implementation and can also be implemented in processors such as CPU\GPU. The process is simple, fast and effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a flow chart of an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the amplitude of the collected signal of this embodiment;

[0020] Figure 3 is a schematic diagram of an autocorrelation curve when a Starlink uplink signal exists in this embodiment; DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0022] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0023] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are orientations or positional relationships based on the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0025] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or display that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed but may include other steps or elements not explicitly listed or inherent to such process, method, product, or display.

[0026] The following will be combined Figure 1-3 , a Ku-band Starlink terminal uplink signal detection method involved in the embodiment of the present application is described in detail. It is worth noting that the following embodiments are only used to explain the present application and do not constitute a limitation on the present application.

[0027] Embodiment 1:

[0028] like Figure 1 As shown, a Ku-band Starlink terminal uplink signal detection method includes the following steps:

[0029] Step 1: The broadband receiver sets the signal frequency and collects the signal IQ data. The sampling rate is fs = 102.4 MHz, the acquisition time is 10 ms, and the complex signal sample is recorded as , the acquisition signal amplitude is as follows Figure 2 As shown, the burst signal is the Starlink uplink signal;

[0030] Step 2: Transform the complex signal samples The autocorrelation operation is performed in packets, and the number of samples in each packet is L:

[0031]

[0032] In the above formula, It is the effective length of the Starlink terminal uplink signal synchronization frame.

[0033] The autocorrelation is calculated using the following formula:

[0034]

[0035] Step 3: To specify the index Perform peak search at , the autocorrelation curve when there is a Starlink uplink signal is as follows Figure 3 shown.

[0036] Step 4: If If a spectrum peak is detected at , it is considered that the Starlink terminal uplink signal is detected and the detection result is reported;

[0037] Step 5: If no spectrum peak is detected, return to step 2 to detect and judge the next packet of data.

[0038] The present invention utilizes the characteristics of the Ku-band Starlink terminal uplink signal to propose a Ku-band Starlink terminal uplink signal detection method, which has high detection sensitivity and greatly improves the signal detection probability.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A Ku-band Starlink terminal uplink signal detection method, characterized in that: The following steps are involved: Step 1: The broadband receiver sets the signal frequency and collects the signal IQ data. The sampling rate is fs, and the complex signal sample is recorded as ; Step 2: Transform the complex signal samples Autocorrelation calculations in packages , the number of samples L in each package should satisfy: ； in, It is the effective length of the synchronization frame of the uplink signal of the Starlink terminal; Step 3: To specify the index Perform peak search at ,here is an integer and 1, The maximum value of The length of ; Step 4: If If a spectrum peak is detected at , it is considered that the Starlink terminal uplink signal is detected and the detection result is reported; Step 5: If no spectrum peak is detected, return to step 2 to detect and judge the next packet of data.

2. A Ku-band Starlink terminal uplink signal detection method according to claim 1, characterized in that: The autocorrelation formula is as follows: 。

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