A method for fast acquisition of high speed burst signals

Abstract

The application discloses a fast acquisition method of high-speed burst signal and relates to the acquisition technical field in a communication system. The application comprises the steps of calculating a correlation value, storing a maximum correlation value, comparing the maximum correlation value with a threshold value and the like, can realize the function of fast acquisition of high-speed burst signal, and saves the storage space to a certain extent. The application is particularly suitable for high-speed signal acquisition in satellite communication.

Description

Technical Field

[0001] This invention relates primarily to the field of acquisition technology in communication systems, and in particular to a method for rapidly acquiring high-speed burst signals. Background Technology

[0002] Acquisition techniques primarily utilize the autocorrelation property. The local code is copied from the received code. By adjusting the phase of the local code to ensure the correlation function between the local code and the received code reaches its peak, the phase of the received code can be determined, thus achieving acquisition. Acquisition methods can be further divided into acquisition with prior knowledge and acquisition without prior knowledge.

[0003] In capture based on no prior knowledge, for any filter, its output... Make the input signal The impulse response of the filter Convolution, i.e. The transfer function of the matched filter is the complex conjugate of the signal to be matched. The output of the matched filter reaches its peak when the received code and the local code are in phase. Therefore, using a matched filter for acquisition has the advantage of high speed and can support functionality at both intermediate frequency (IF) and baseband. However, for high-speed burst signals, the correlation operations between the received code and the local code require storing a large number of correlation values, consuming significant hardware resources. Summary of the Invention

[0004] In view of this, the present invention proposes a fast acquisition method for high-speed burst signals. Based on the principle of matched filter method, the method calculates the correlation value by grouping and only stores the maximum correlation value calculated at the same time, thereby saving storage space and shortening the compilation time.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for rapidly acquiring high-speed burst signals includes the following steps:

[0007] (1) Receive 8 parallel signals with an oversampling factor of 4. ;

[0008] (2) To Storage is performed at a depth equal to the frame header length; since there are 8 sampling points per clock cycle, and 4 sampling points constitute one symbol, there are 2 symbols per clock cycle. , Assume that at time k, the 8 sampling points obtained by performing a 4x oversampling on the 8 parallel signals are as follows: , , , , , , , ,but , , , For the first symbol , , , , For the second symbol ;

[0009] (3) Divide the sampling points within the two symbols at time k into 4 groups;

[0010] (4) Perform correlation calculations between the four sets of sampling points and the local code to obtain four correlation values. Compare the four correlation values ​​and take the largest correlation value. Store the data; the specific method for calculating the four relevant values ​​is as follows: Take... and As the received code, it is correlated with the local code to obtain the correlation value result. ;Pick and As the received code, it is correlated with the local code to obtain the correlation value result. ;Pick and As the received code, it is correlated with the local code to obtain the correlation value result. ;Pick and As the received code, it is correlated with the local code to obtain the correlation value result. Thus, four correlation values ​​are obtained at time k. , , , ;

[0011] (5) The amplitude is calculated and compared with the set threshold value. If the amplitude is greater than the threshold, the acquisition is considered successful; if the amplitude is not greater than the threshold value, the signal is considered not acquired. The above steps are repeated until the acquisition is successful.

[0012] Compared with the methods in the prior art, the present invention has the following advantages:

[0013] 1. This invention requires less storage of related calculation results and occupies fewer hardware resources, making it easier to implement in engineering.

[0014] 2. This invention only stores the maximum correlation value calculated at the same time, thus saving storage space and shortening compilation time compared to the traditional matched filter capture method that uses all samples for correlation calculation. Attached Figure Description

[0015] Figure 1 This is a flowchart of the present invention.

[0016] Figure 2 This is a schematic diagram illustrating the process of calculating correlation values ​​for grouping. Detailed Implementation

[0017] The present invention will now be described in further detail:

[0018] A method for capturing high-speed burst signals, such as Figure 1 As shown, it includes the following steps:

[0019] (1) Receive 8 parallel signals with an oversampling factor of 4. ;

[0020] (2) To Storage is performed at a depth equal to the frame header length. Since there are 8 sampling points per clock cycle, and 4 sampling points constitute one symbol, there are 2 symbols per clock cycle. , ;

[0021] (3) Divide the sampling points within the two symbols at time k into 4 groups. In engineering applications, the number of groups of sampling points can be determined according to the actual situation.

[0022] (4) Obtain the appropriate original polynomial by looking up the table, and generate the local code according to the original polynomial. Perform correlation value calculations between the four sets of samples and the local code to obtain four correlation values. Compare the four correlation values ​​and take the largest correlation value. Store, such as Figure 2 As shown;

[0023] (5) The amplitude is calculated and compared with the set threshold value. If the amplitude is greater than the threshold, the acquisition is considered successful; if the amplitude is not greater than the threshold value, the signal is considered not acquired. The above steps are repeated until the acquisition is successful.

[0024] Furthermore, the specific process of step (2) is as follows: Assume that at time k, the 8 sampling points obtained by performing a 4x oversampling on the 8 parallel signals are as follows: , , , , , , , .in , , , For the first symbol , , , , For the second symbol .

[0025] Furthermore, the specific method for calculating the four relevant values ​​in step (4) is as follows: take and As the received code, it is correlated with the local code to obtain the correlation value result. ;Pick and As the received code, it is correlated with the local code to obtain the correlation value result. ;Pick and As the received code, it is correlated with the local code to obtain the correlation value result. ;Pick and As the received code, it is correlated with the local code to obtain the correlation value result. Thus, four correlation values ​​are obtained at time k. , , , .

[0026] In summary, this invention includes steps such as grouping and calculating correlation values, storing the maximum correlation value, and comparing the maximum correlation value with the threshold value. It can achieve the function of quickly capturing high-speed burst signals, while saving storage space to a certain extent, speeding up the compilation process, and being easy to implement in engineering. It is particularly suitable for high-speed signal capture in satellite communications.

[0027] The contents not described in detail in this invention are common knowledge in the field.

[0028] The above description is one specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art based on the technical solution and inventive concept of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for rapidly acquiring high-speed burst signals, characterized in that, Includes the following steps: (1) Receive 8 parallel signals with an oversampling factor of 4. ; (2) To Storage is performed at a depth equal to the frame header length; since there are 8 sampling points per clock cycle, and 4 sampling points constitute one symbol, there are 2 symbols per clock cycle. , Assume that at time k, the 8 sampling points obtained by performing a 4x oversampling on the 8 parallel signals are as follows: , , , , , , , ,but , , , For the first symbol , , , , For the second symbol ; (3) Divide the sampling points within the two symbols at time k into 4 groups; (4) Perform correlation calculations between the four sets of sampling points and the local code to obtain four correlation values. Compare the four correlation values ​​and take the largest correlation value. Store the data; the specific method for calculating the four relevant values ​​is as follows: Take... and As the received code, it is correlated with the local code to obtain the correlation value result. ;Pick and As the received code, it is correlated with the local code to obtain the correlation value result. ;Pick and As the received code, it is correlated with the local code to obtain the correlation value result. ;Pick and As the received code, it is correlated with the local code to obtain the correlation value result. Thus, four correlation values ​​are obtained at time k. , , , ; (5) The amplitude is calculated and compared with the set threshold value. If the amplitude is greater than the threshold, the acquisition is considered successful; if the amplitude is not greater than the threshold value, the signal is considered not acquired. The above steps are repeated until the acquisition is successful.

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