Satellite signal waveform design and transmission method and system based on artificial mixed noise

Abstract

The invention provides a satellite signal waveform design and transmission method and system based on artificial mixed noise, and the method comprises the steps: generating original bit information, and further obtaining transmission data x (t); generating a random sequence m1 (t), and further obtaining a sequence g1 (t) to be used; generating a new random sequence m2 (t) by using the g1 (t); the x (t) is multiplied by the m2 (t) to obtain g2 (t), and the g1 (t) and the g2 (t) are added according to a certain power distribution rule to obtain y (t); performing down-conversion on the received signal to obtain y (t); the receiving end locally generates g1 (t) and m2 (t) which are the same as those of the transmitting end; and performing time delay estimation by using y (t) and g1 (t) to obtain a transmission time delay # imgabs0 #, synchronizing data by using # imgabs1 #, eliminating g1 (t) to obtain # imgabs2 #, further eliminating m2 (t) from the data # imgabs3 # after g1 (t) is eliminated to obtain # imgabs4 #, and de-mapping the # imgabs5 # to obtain an original information bit. Through numerical simulation verification, the transmission waveform safety can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a satellite signal waveform design and transmission method and system based on artificial mixed noise. Background Art

[0002] Due to the openness of the spatial channel, communication transmission needs to consider the security of its waveform. In the context of various traditional modulation waveforms being easily intercepted, some new waveform design methods have emerged in recent years, such as transform domain processing, signal masking and other technologies. These technologies can enhance the security of communication waveforms to a certain extent. Transform domain processing technology mathematically processes the signal in different transform domains to obtain a new transmission waveform in the time / frequency domain, but its transform parameters can be identified through certain technical means. In addition, if the masked signal in the signal masking technology is intercepted, it is difficult to play a protective role. Summary of the invention

[0003] Based on the purpose of improving the security of communication transmission waveform, the present invention provides a satellite signal waveform design and transmission method and system based on artificial mixed noise. By using two effective cover modes to mix the transmission signal, the difficulty of demodulation by non-cooperative parties is increased, the defects of the prior art are compensated, and the robustness of the system is enhanced.

[0004] The present invention provides a satellite signal waveform design and transmission method based on artificial mixed noise, comprising the following steps:

[0005] Transmitter:

[0006] Step 1: Generate original bit information, and obtain the transmission data x(t) at time t based on the original bit information;

[0007] Step 2: Generate a random sequence m1(t), and obtain the sequence g1(t) to be used based on the random sequence m1(t);

[0008] Step 3: Generate a new random sequence m2(t) using the sequence to be used g1(t);

[0009] Step 4: Multiply the transmission data x(t) with the random sequence m2(t) to obtain the sequence g2(t).

[0010] Step 5: Add the sequence g1(t) to be used and the sequence g2(t) according to a certain power allocation rule to obtain y(t), and up-convert y(t) and transmit it through the antenna;

[0011] Receiver:

[0012] Step 6: Down-convert the received signal to obtain the signal to be processed y(t);

[0013] Step 7: The receiving end first generates locally the same sequence g1(t) and random sequence m2(t) to be used as those of the transmitting end;

[0014] Step 8: Use the signal to be processed y(t) and the sequence to be used g1(t) to estimate the delay and obtain the transmission delay

[0015] Step 9: Use Transmission Delay Synchronize the data and eliminate the sequence to be used g1(t), and get

[0016] Step 10: Eliminate the data after the sequence g1(t) to be used Further eliminating the random sequence m2(t), we get

[0017] Step 11: Convert the data from step 10 Demapping is to obtain the original information bits.

[0018] Furthermore, in step 1, the original bit information is first subjected to M-order QAM modulation and then to shaping filtering to obtain the transmission data x(t) at time t.

[0019] Furthermore, in step 2, the random sequence m1(t) is subjected to shaping filtering to obtain the sequence g1(t) to be used.

[0020] Furthermore, in step 3, the random sequence m2(t) is expressed as:

[0021]

[0022] Where K is the phase modulation sensitivity, is the initial phase; the sequence to be used g1(t) and the random sequence m2(t) maintain a one-to-one correspondence at each moment.

[0023] Furthermore, in step 5, the transmission model of the system at time t is expressed as:

[0024] y(t)=h(t)·[p1·g1(t)+p2·g2(t)]+n(t)

[0025] Where h(t) represents the channel gain at time t, p1 and p2 represent the power allocation factors, and p1+p2=1, and n(t) represents a mean of 0 and a variance of σ 2 Gaussian noise.

[0026] Furthermore, in step 8, the transmission delay is estimated using the cross-correlation method.

[0027] Furthermore, the transmission delay It is expressed as:

[0028]

[0029] Among them, argmax{·} means to find the maximum value of the function, and R(·,·) means the cross-correlation calculation, which is

[0030] Furthermore, in step 9, the random sequence g1(t) is firstly transformed into the transmission delay estimated in step 8. Perform delay compensation and obtain Next, estimate the channel gain Finally, eliminate the random sequence g1(t) and get the eliminated data Expressed as

[0031] Furthermore, in step 10, the random sequence m2(t) is firstly transformed into the transmission delay estimated in step 8. Perform delay compensation and obtain Secondly, eliminate the influence of the random sequence m2(t), and get Specifically expressed as

[0032] The present invention also provides a satellite signal waveform design and transmission system based on artificial mixed noise, including a transmitting end and a receiving end;

[0033] The transmitting end and the receiving end are used to execute the above-mentioned satellite signal waveform design and transmission method based on artificial mixed noise.

[0034] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0035] The present invention uses two effective cover modes to mix transmission signals, thereby increasing the difficulty of demodulation for non-cooperative parties, making up for the defects of the prior art, and enhancing the robustness of the system. Numerical simulation verification shows that the security of the transmission waveform can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a principle block diagram of a satellite signal waveform design and transmission method based on artificial mixed noise in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example

[0040] like Figure 1 As shown, this embodiment proposes a satellite signal waveform design and transmission method based on artificial mixed noise, comprising the following steps:

[0041] Transmitter:

[0042] Step 1: Generate original bit information, first subject the original bit information to M-order QAM modulation, and then pass it through shaping filtering to obtain the transmission data x(t) at time t.

[0043] Step 2: Generate a random sequence m1(t) in a custom manner, and obtain the sequence g1(t) to be used by subjecting the random sequence m1(t) to shaping filtering.

[0044] Step 3: Use the sequence to be used g1(t) in step 2 to generate a new random sequence m2(t).

[0045] The specific method of generating the random sequence m2(t) is: Where K is the phase modulation sensitivity, is the initial phase. The sequence to be used g1(t) and the random sequence m2(t) are in one-to-one correspondence, that is, at time t1,

[0046] Step 4: Multiply the transmission data x(t) generated in step 1 by the random sequence m2(t) generated in step 3, expressed as g2(t)=x(t)·m2(t), where [·] represents symbol multiplication.

[0047] Step 5: Add the random sequence g1(t) in step 2 and the sequence g2(t) obtained in step 4 according to a certain power allocation rule to obtain y(t), and up-convert y(t) and transmit it through the antenna. The transmission model of the system at time t is expressed as y(t) = h(t) · [p1 · g1(t) + p2 · g2(t)] + n(t), where h(t) represents the channel gain at time t, p1 and p2 represent the power allocation factors respectively, and satisfy p1 + p2 = 1, and n(t) represents a mean of 0 and a variance of σ 2 Gaussian noise.

[0048] Receiver:

[0049] Step 6: Down-convert the received signal to obtain the signal to be processed y(t).

[0050] Step 7: The receiving end first generates locally the same sequence g1(t) and random sequence m2(t) to be used as those of the transmitting end, and the generation methods are the same as those of steps 2 and 3 respectively.

[0051] Step 8: Use the signal to be processed y(t) after down-conversion in step 6 and the random sequence g1(t) generated in step 7 to estimate the delay, and use the cross-correlation method to estimate the transmission delay.

[0052] The specific estimation method is expressed as Among them, argmax{·} means to find the maximum value of the function, and R(·,·) means the cross-correlation calculation, which is In step 3, the delays of the sequence to be used g1(t) and the random sequence m2(t) are kept in one-to-one correspondence, so only one transmission delay needs to be estimated. That's it.

[0053] Step 9: Use the data synchronized in step 8 to perform interference elimination on the random sequence g1(t).

[0054] First, the random sequence g1(t) is transformed into the transmission delay estimated in step 8 Perform delay compensation and obtain Next, estimate the channel gain Finally, eliminate the random sequence g1(t) and get the eliminated data Expressed as

[0055] Step 10: Eliminate the random sequence g1(t) in step 9 Further eliminate the influence of the random sequence m2(t).

[0056] First, the random sequence m2(t) is transmitted using the transmission delay estimated in step 8 Perform delay compensation and obtain Secondly, eliminate the influence of the random sequence m2(t), and get Specifically expressed as

[0057] Step 11: Convert the data from step 10 Demapping is to obtain the original information bits.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A satellite signal waveform design and transmission method based on artificial mixed noise, characterized in that: The steps include: Transmitter: Step 1: Generate original bit information, and obtain the transmission data x(t) at time t based on the original bit information; Step 2: Generate a random sequence m1(t), and obtain the sequence g1(t) to be used based on the random sequence m1(t); Step 3: Generate a new random sequence m2(t) using the sequence to be used g1(t); Step 4: Multiply the transmission data x(t) with the random sequence m2(t) to obtain the sequence g2(t). Step 5: Add the sequence g1(t) to be used and the sequence g2(t) according to a certain power allocation rule to obtain y(t), and up-convert y(t) and transmit it through the antenna; Receiver: Step 6: Down-convert the received signal to obtain the signal to be processed y(t); Step 7: The receiving end first generates locally the same sequence g1(t) and random sequence m2(t) to be used as those of the transmitting end; Step 8: Use the signal to be processed y(t) and the sequence to be used g1(t) to estimate the delay and obtain the transmission delay Step 9: Use Transmission Delay Synchronize the data and eliminate the sequence to be used g1(t), and get Step 10: Eliminate the data after the sequence g1(t) to be used Further eliminating the random sequence m2(t), we get Step 11: Convert the data from step 10 Demapping is to obtain the original information bits.

2. The satellite signal waveform design and transmission method based on artificial mixed noise according to claim 1 is characterized in that: In step 1, the original bit information is first modulated by M-order QAM and then subjected to shaping filtering to obtain the transmission data x(t) at time t.

3. The satellite signal waveform design and transmission method based on artificial mixed noise according to claim 1, characterized in that: In step 2, the random sequence m1(t) is subjected to shaping filtering to obtain the sequence g1(t) to be used.

4. The satellite signal waveform design and transmission method based on artificial mixed noise according to claim 1, characterized in that: In step 3, the random sequence m2(t) is expressed as: Where K is the phase modulation sensitivity, is the initial phase; the sequence to be used g1(t) and the random sequence m2(t) maintain a one-to-one correspondence at each moment.

5. The satellite signal waveform design and transmission method based on artificial mixed noise according to claim 1, characterized in that: In step 5, the transmission model of the system at time t is expressed as: y(t)=h(t)[p1·g1(t)+p·2·g2(t)]+n(t) Where h(t) represents the channel gain at time t, p1 and p2 represent the power allocation factors, and p1+p2=1, and n(t) represents a mean of 0 and a variance of σ 2 Gaussian noise.

6. The satellite signal waveform design and transmission method based on artificial mixed noise according to claim 1, characterized in that: In step 8, the transmission delay is estimated using the cross-correlation method 7. The satellite signal waveform design and transmission method based on artificial mixed noise according to claim 1, characterized in that: Transmission delay It is expressed as: Among them, argmax{·} means to find the maximum value of the function, and R(·,·) means the cross-correlation calculation, which is 8. The satellite signal waveform design and transmission method based on artificial mixed noise according to claim 1, characterized in that: In step 9, the random sequence g1(t) is first transformed using the transmission delay estimated in step 8 Perform delay compensation and obtain Next, estimate the channel gain Finally, eliminate the random sequence g1(t) and get the eliminated data Expressed as 9. The satellite signal waveform design and transmission method based on artificial mixed noise according to claim 1, characterized in that: In step 10, the random sequence m2(t) is first transmitted using the transmission delay estimated in step 8 Perform delay compensation and obtain Secondly, eliminate the influence of the random sequence m2(t), and get Specifically expressed as 10. A satellite signal waveform design and transmission system based on artificial mixed noise, characterized in that: Includes a transmitter and a receiver; The transmitting end and the receiving end are used to execute the satellite signal waveform design and transmission method based on artificial mixed noise as described in any one of claims 1-9.

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