Multi-tone signal assisted distributed node wideband signal transmission phase coherent synthesis system and method

Abstract

The application discloses a kind of multi-tone signal auxiliary distributed node wideband signal emission phase-comparison synthesis system and method, belong to antenna technical field, method includes the following steps: first, N emission node keeps uplink signal frequency source synchronization, and emits modulated signal and multi-tone signal;Subsequently, by down-conversion and low-pass filtering respectively extracted multiple single-tone signals received at receiving node;Then, according to the phase difference and time difference between the decoupled multi-tone signal estimation N emission node, and by loop filtering to track prediction;Finally, by time delay filtering pre-compensation time difference between nodes at emission node, while pre-compensation phase difference between nodes, ensure the maximization of wideband signal emission phase-comparison synthesis gain.The application is suitable for the wideband signal emission phase-comparison synthesis in the case of distributed high dynamic node, real-time is high and easy to realize, can improve the gain and efficiency of wideband signal phase-comparison synthesis.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and more specifically, to a distributed node broadband signal transmission coherent synthesis system and method assisted by multi-tone signals. Background Art

[0002] Distributed coherent systems are often used in many fields such as deep space telemetry and remote control, ultra-long-range radar detection, and radio astronomy. Transmit beam coherence is achieved by coherently adjusting the transmitted signals of distributed nodes so that they can reach the receiving node simultaneously and in phase and focus the energy, maximizing the gain of the node's transmit coherent synthesis, thereby achieving long-distance, high-precision communication, detection, and tracking.

[0003] Existing distributed transmit coherent synthesis methods typically consider the coherent synthesis of narrowband signals, ignoring the signal envelope delay inconsistencies caused by the distance between the transmitting and receiving nodes, and assuming that the positions of the distributed nodes remain stationary. However, when considering the coherent synthesis of broadband signal transmissions in the case of highly dynamic distributed nodes, the signal envelope delay inconsistencies caused by the distance between the transmitting and receiving nodes cannot be ignored. In addition, mobile nodes cause the phase difference and delay variation between nodes to become real-time. Both of these factors render traditional narrowband transmit coherent synthesis methods unsuitable. Therefore, finding real-time and efficient time difference and phase difference estimation methods suitable for highly dynamic nodes is crucial to improving the gain and efficiency of broadband signal transmission coherent synthesis. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a distributed node broadband signal transmission coherent synthesis system and method assisted by multi-tone signals, which is suitable for broadband signal transmission coherent synthesis in distributed high-dynamic node conditions, has high real-time performance and is easy to implement, and can improve the gain and efficiency of broadband signal coherent synthesis.

[0005] The object of the present invention is achieved through the following solutions:

[0006] A multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis system, comprising:

[0007] A high-dynamic distributed node broadband signal transmission model establishment module is used to enable N transmitting nodes to maintain uplink signal frequency source synchronization by enabling reset, and then transmit uplink modulated signals and multi-tone signals through T components;

[0008] The multi-tone signal extraction module captures the Doppler shift at the receiving node through the R component, and then extracts the multiple received single-tone signals through down-conversion and low-pass filtering.

[0009] a parameter estimation module, estimating the phase difference and time difference between any two transmitting nodes by using the multiple single-tone signals decoupled by the multiple-tone signal extraction module, and tracking and predicting the phase difference and time difference by loop filtering;

[0010] a parameter tracking and predicting module, tracking and predicting the phase difference and time difference between any two transmitting nodes by loop filtering;

[0011] a performance evaluation module, pre-compensating the phase difference and time difference between nodes by time delay filtering at the transmitting nodes, and calculating the gain and efficiency of the wideband signal transmission phase coherent synthesis at the receiving nodes.

[0012] Further, the N transmitting nodes specifically include two transmitting nodes.

[0013] Further, the capturing of the Doppler shift by the R component at the receiving nodes specifically includes capturing the Doppler shift by the R component in real time at the receiving nodes.

[0014] Further, the tracking and predicting of the phase difference and time difference by loop filtering specifically includes tracking and predicting the phase difference and time difference in real time by loop filtering.

[0015] Further, the tracking and predicting of the phase difference and time difference between any two transmitting nodes by loop filtering specifically includes tracking and predicting the phase difference and time difference between any two transmitting nodes in real time by loop filtering.

[0016] Further, the calculation of the gain and efficiency of the wideband signal transmission phase coherent synthesis at the receiving nodes specifically includes calculating the gain and efficiency of the wideband signal transmission phase coherent synthesis in real time at the receiving nodes.

[0017] A multiple-tone signal assisted distributed node wideband signal transmission phase coherent synthesis method, including the following steps:

[0018] First, N transmitting nodes keep the uplink signal frequency source synchronized, and transmit modulated signals and multiple-tone signals;

[0019] Next, multiple single-tone signals received are extracted by down-conversion and low-pass filtering at the receiving nodes;

[0020] Then, the phase difference and time difference between N transmitting nodes are estimated according to the decoupled multiple-tone signals, and are tracked and predicted by loop filtering;

[0021] Finally, the time difference between nodes is pre-compensated by time delay filtering at the transmitting nodes, and the phase difference between nodes is pre-compensated, so as to ensure the maximization of the gain of the wideband signal transmission phase coherent synthesis.

[0022] Furthermore, the N transmitting nodes maintain uplink signal frequency source synchronization and transmit the modulated signal and the multi-tone signal, specifically including the sub-steps of:

[0023] Step 1-1: Denote the modulated signal and the positive and negative single-tone signals transmitted from the nth node to the receiving node as s n (t), s n1 (t), s n2 (t), its specific expression is:

[0024]

[0025] Where n = 1, ..., N, p(t) represents the broadband modulated signal transmitted by the node; f0 represents the frequency of the carrier signal of the same source of N transmitting nodes, f n Indicates the frequency of the positive / negative single-tone signal transmitted by the nth transmitting node; f v represents the Doppler shift; τ n ,θ n They represent the propagation delay and initial phase from the nth transmitting node to the receiving node respectively;

[0026] Step 1-2: Take the first transmitting node as the reference node, and the single tone frequency difference between the nth transmitting node and the first transmitting node is Δf n =f n -f1, the first node and the nth node each transmit a positive single-tone signal to the receiving node, denoted as s n3 (t), s n4 (t), its specific expression is:

[0027]

[0028] Step 1-3: The specific expression of the received signal at the receiving node is:

[0029]

[0030] Step 1-4: If the first transmitting node is used as a reference, the phase difference between the nth transmitting node and the first transmitting node is:

[0031] ΔΦ n1 =2π(f0+f v )(τ n -τ1)+(θ n -θ1), n=2,…,N.

[0032] Furthermore, the multiple single-tone signals received are extracted at the receiving node by down-conversion and low-pass filtering, specifically including the sub-steps of: down-converting and low-pass filtering the multi-tone signals received at the receiving node in sequence, and decoupling the zero-frequency single-tone signals to obtain the following:

[0033]

[0034] Further, the estimating phase difference and time difference between N transmitting nodes according to the decoupled multi-tone signal comprises the following steps:

[0035] Step 3-1: if multiplying signal s n1 (t) with s n2 (t), the following signal is obtained:

[0036]

[0037] Step 3-2: taking the first transmitting node as reference, multiplying s with the conjugate of s , the following signal is obtained:

[0038]

[0039] Step 3-3: the phase difference estimation value of the nth transmitting node compared with the first transmitting node is:

[0040] wherein, φ represents the solution of phase;

[0041] Step 3-4: multiplying the conjugate of signal s n2 (t) with s n3 (t), the following signal is obtained:

[0042]

[0043] Step 3-5: taking the first transmitting node as reference, multiplying the conjugate of signal s 12 (t) with s n4 (t), the following signal is obtained:

[0044]

[0045] Step 3-6: multiplying s with s , the following signal is obtained:

[0046]

[0047] Step 3-7: the time difference estimation value between the nth transmitting node and the first transmitting node is:

[0048]

[0049] Further, the tracking prediction through loop filtering comprises the following steps:

[0050] Step 4-1: The phase difference between the nthtransmitting node and the first transmitting node is tracked by the loop filter at the kthmoment as follows:

[0051] δ Φ (k)=δ Φ (k-1)+b0x Φ (n)+b1x Φ (n-1);

[0052]

[0053] wherein, ζ is an empirical value, B L represents the noise bandwidth, T s is the update period of the loop filter; x Φ (k), δ Φ (k), respectively represent the phase difference at the kthmoment, the loop filter output result and the phase difference prediction result.

[0054] Step 4-2: The time difference between the nthtransmitting node and the first transmitting node is tracked by the loop filter at the kthmoment as follows:

[0055] δ τ (k)=δ τ (k-1)+b0x τ (n)+b1x τ (n-1)

[0056]

[0057] wherein, x τ (k), δ τ (k), respectively represent the phase difference at the kthmoment, the loop filter output result and the phase difference prediction result.

[0058] Further, the time difference between the transmitting nodes is pre-compensated by the time delay filter at the transmitting node, and the phase difference between the transmitting nodes is pre-compensated, so as to maximize the gain of the wideband signal transmitting phase synthesis, and the specific steps include:

[0059] Step 5-1: The phase difference and time difference estimation results are fed back to the transmitting node, and the time delay filter is used to compensate the time difference between the N-1 transmitting nodes and the first transmitting node, and the specific expression is as follows:

[0060]

[0061] wherein, h n(t) represents the continuous delay filter, f t represents the cutoff frequency of the continuous domain;

[0062] When processing in the discrete domain, the corresponding time delay filter is

[0063]

[0064] Among them, f n represents the normalized cutoff frequency in the discrete domain, f n =f t / f s , f s is the sampling rate; D is the delay, N represents the order of the delay filter;

[0065] Step 5-2: After phase pre-compensation, the coherent synthesis signal at the receiving node C is

[0066]

[0067] Step 5-3: Calculate the gain and efficiency of the coherent synthesis of N transmitting nodes:

[0068]

[0069] The beneficial effects of the present invention include:

[0070] (1) The present invention can realize coherent synthesis of broadband signal transmission. The embodiment of the present invention provides a method for coherent synthesis of broadband signal transmission applicable to highly dynamic distributed nodes. Through multi-tone assistance, the phase difference and time difference between transmitting nodes can be simply and quickly estimated simultaneously.

[0071] (2) The present invention can achieve real-time tracking and prediction of parameters. The embodiment of the present invention provides a method for coherent synthesis of broadband signal transmission suitable for highly dynamic distributed nodes. The method uses loop filtering to track and predict the phase difference and time difference between transmitting nodes in real time. It also uses delay filtering to pre-compensate the time difference between nodes in real time and compensate the phase difference between nodes at the same time, thereby maximizing the gain of broadband signal transmission coherent synthesis.

[0072] (3) The present invention has the characteristic of flexible system expansion. The embodiment of the present invention provides a multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis method, which can be expanded to a broadband signal coherent synthesis system with any number of transmitting nodes, and the easy-to-implement method ensures the stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0074] Figure 1 This is a block diagram of the structural principle of the system according to an embodiment of the present invention;

[0075] Figure 2 Schematic diagram of the spatial geometry of transmitting nodes A, B and mobile receiving node C;

[0076] Figure 3 is the sum of the six-channel single-tone signals and the modulated signal received by node C;

[0077] Figure 4 Node C sequentially performs down-conversion and low-pass filtering on the six received single-tone signals;

[0078] Figure 5 Phase difference and time difference changes between transmitting nodes A and B predicted by loop filter tracking

[0079] Figure 6 A delay filter is used to compensate for the time difference between transmitting nodes A and B;

[0080] Figure 7 The result of pre-compensation of the time difference and phase difference of the modulated signal at the transmitting node B;

[0081] Figure 8 Perform down-conversion and low-pass filtering on the received coherent modulated signal for node C;

[0082] Figure 9 The coherent synthesis gain changes are transmitted at node C based on the prediction parameter results of the loop filter tracking. DETAILED DESCRIPTION

[0083] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0084] Given the current situation, the following technical solutions are proposed to address the problem that traditional narrowband transmit coherent synthesis methods are not applicable to the estimation of time difference and phase difference of broadband signals in highly dynamic distributed node environments:

[0085] In a preferred embodiment, a multi-tone signal assisted distributed node broadband signal transmission coherent synthesis system is proposed, such as Figure 1As shown, the specific settings are:

[0086] A high-dynamic distributed node broadband signal transmission model establishment module is used to enable N transmitting nodes to maintain uplink signal frequency source synchronization by enabling reset, and then transmit uplink modulated signals and multi-tone signals through T components;

[0087] The multi-tone signal extraction module captures the Doppler shift at the receiving node through the R component, and then extracts the multiple received single-tone signals through down-conversion and low-pass filtering.

[0088] The parameter estimation module uses the multiple single-tone signals decoupled by the multi-tone signal extraction module to estimate the phase difference and time difference between any two transmitting nodes, and tracks and predicts the phase difference and time difference through loop filtering;

[0089] Parameter tracking and prediction module, used to track and predict the phase difference and time difference between any two transmitting nodes through loop filtering;

[0090] The performance evaluation module is used to pre-compensate the time difference between nodes through delay filtering at the transmitting node, and pre-compensate the phase difference between nodes, and then calculate the gain and efficiency of the coherent synthesis of broadband signal transmission at the receiving node.

[0091] On the other hand, in a preferred embodiment, see Figure 2-Figure 9 The present invention provides a multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis method, which performs the following steps:

[0092] Step 1: Establish a highly dynamic distributed node broadband signal transmission model. N transmitting nodes maintain uplink signal frequency source synchronization by enabling reset, and then transmit uplink modulated signals and multi-tone signals through T components.

[0093] Step 2: Establish a multi-tone signal extraction module. At the receiving node, the R component is used to capture the Doppler shift in real time. Then, multiple received single-tone signals are extracted through down-conversion and low-pass filtering.

[0094] Step 3: Establish a parameter estimation module. This module uses the multiple single-tone signals decoupled by the multi-tone signal extraction module to estimate the phase difference and time difference between any two transmitting nodes. It then uses loop filtering to track and predict the phase difference and time difference in real time.

[0095] Step 4: Establish a parameter tracking and prediction module. The parameter tracking and prediction module uses loop filtering to track and predict the phase difference and time difference between any two transmitting nodes in real time.

[0096] Step 5: Establish a performance evaluation module. The performance evaluation module pre-compensates the time difference between nodes through delay filtering at the transmitting node, and pre-compensates the phase difference between nodes. Then, it calculates the gain and efficiency of the coherent synthesis of broadband signal transmission in real time at the receiving node.

[0097] In order to illustrate the distributed high-dynamic node broadband signal transmission coherent synthesis method, the specific processing steps are further described as follows:

[0098] Establish a high-dynamic distributed node broadband signal transmission model. Figure 2 , a spatial geometric diagram of two transmitting nodes and a single receiving node is given; assuming that the position coordinates of transmitting node A are (1, 0, 0) m, the position coordinates of transmitting node B are (1, 1, 4) m, the initial position of receiving node C is (0, 0, 15) km, and receiving node C moves at a uniform speed of (0, 0.5, 1) km / s, and receiving node C moves within 0 to 12.45 s.

[0099] See Figure 3 , the six-channel single-tone signals and modulation signals transmitted by the transmitting node A and the transmitting node B to the receiving node C are given, where the single-tone signals are represented by s 11 (t), s 12 (t), s 21 (t), s 22 (t), s 23 (t), s 24 (t). The frequency of the homologous carrier signal is f0 = 2.2 GHz, and the bandwidth of the modulated signal p(t) transmitted by the transmitting nodes A and B is 10 MHz, and the signal sampling rate is f s =200MHz. The positive and negative single-tone signal frequencies of transmitting nodes A and B are f1 = 20MHz, f2 = 18MHz, and Δf n =2MHz; transmitting nodes A and B send a positive tone signal respectively, with frequencies of 22MHz and 16MHz.

[0100] Establish a multi-tone signal extraction module. Figure 4 , gives the results of down-converting and low-pass filtering the four single-tone signals received at the receiving node C in sequence, and obtaining six zero-frequency received signals.

[0101] Establishing a parameter estimation module includes the following steps:

[0102] Step 3-1: Transform the signal s n1 (t) and s n2 (t) multiplied by

[0103]

[0104] Step 3-2: Taking the first transmitting node as a reference, and Multiplying the conjugate of , we get:

[0105]

[0106] Step 3-3: The estimated phase difference between the nth transmitting node and the first transmitting node is:

[0107]

[0108] Step 3-4: Transform the signal s n2 The conjugate of (t) and s n3 (t) multiplied by

[0109]

[0110] Step 3-5: Taking the first transmitting node as the reference, transmit the signal s 12 The conjugate of (t) and s n4 (t) multiplied by

[0111]

[0112] Step 3-6: and Multiplying them, we get:

[0113]

[0114] Step 3-7: The estimated time difference between the nth transmitting node and the first transmitting node is:

[0115]

[0116] Build a parameter tracking and prediction module. Figure 5 , gives the results of loop filter tracking and prediction of time difference and phase difference, where the loop filter update period T s =50ms, ζ is 0.707, and the noise bandwidth is B L =10Hz,ω n =18.9rad / s.

[0117] Establish a performance evaluation module. The specific steps include:

[0118] See Figure 6-Figure 7 , used to pre-compensate the time difference between the transmitting nodes A and B, and the delay filter for the modulated signal at the transmitting node B. and phase difference Pre-compensation result, normalized cutoff frequency f of discrete domain delay filter n =0.4, D=-2.921, N=80.

[0119] See Figure 8 After down-converting and low-pass filtering the modulated signals transmitted by nodes A and B, the coherent synthesis result at the receiving node C is:

[0120]

[0121] See Figure 9 According to the loop filter tracking prediction parameter results, the coherent synthesis gain changes at node C. It can be seen that the gain and efficiency of the coherent synthesis of the broadband signals transmitted by nodes A and B are:

[0122]

[0123] The specific implementation of the present invention is not limited to the above-mentioned methods. The above description is only the preferred embodiment of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. It is obvious that various changes, adjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the principles and concepts of the present invention, it can also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis system, characterized in that: include: High dynamic distributed node broadband signal transmission model establishment module, used to make Each transmitting node keeps the uplink signal frequency source synchronized by enabling reset, and then transmits the uplink modulated signal and multi-tone signal through the T component; The multi-tone signal extraction module captures the Doppler shift at the receiving node through the R component, and then extracts the received multi-tone signals through down-conversion and low-pass filtering. The parameter estimation module uses the multi-tone signal decoupled by the multi-tone signal extraction module to estimate the phase difference and time difference between any two transmitting nodes, and then tracks and predicts the phase difference and time difference through loop filtering; Parameter tracking and prediction module, used to track and predict the phase difference and time difference between any two transmitting nodes through loop filtering; The performance evaluation module is used to pre-compensate the time difference between nodes through delay filtering at the transmitting node, and pre-compensate the phase difference between nodes, and then calculate the gain and efficiency of the coherent synthesis of broadband signal transmission at the receiving node.

2. The multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis system according to claim 1, characterized in that: described The transmitting nodes specifically include two transmitting nodes.

3. The multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis system according to claim 1, characterized in that: The capturing of the Doppler shift by using the R component at the receiving node specifically includes: capturing the Doppler shift in real time by using the R component at the receiving node.

4. The multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis system according to claim 1, characterized in that: Tracking and predicting the phase difference and time difference through loop filtering specifically includes: tracking and predicting the phase difference and time difference in real time through loop filtering.

5. The multi-tone signal assisted distributed node broadband signal transmission coherent synthesis system according to claim 1, characterized in that: Tracking and predicting the phase difference and time difference between any two transmitting nodes through loop filtering specifically includes: tracking and predicting the phase difference and time difference between any two transmitting nodes in real time through loop filtering.

6. The multi-tone signal assisted distributed node broadband signal transmission coherent synthesis system according to claim 1, characterized in that: The calculating the gain and efficiency of the wideband signal transmission coherent synthesis at the receiving node specifically includes: calculating the gain and efficiency of the wideband signal transmission coherent synthesis in real time at the receiving node.

7. A multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis method, characterized in that: The steps include: first, Each transmitting node keeps the uplink signal frequency source synchronized and transmits the modulated signal and multi-tone signal; Then, at the receiving node, the received multi-tone signals are extracted by down-conversion and low-pass filtering; Then, the decoupled multi-tone signal is estimated The phase difference and time difference between the transmitting nodes are tracked and predicted through loop filtering; Finally, at the transmitting node, delay filtering is used to pre-compensate the time difference between nodes and the phase difference between nodes to ensure the maximization of the coherent synthesis gain of the broadband signal transmission.

8. The multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis method according to claim 7, characterized in that: described A transmitting node maintains uplink signal frequency source synchronization and transmits a modulated signal and a multi-tone signal, specifically including the following sub-steps: Step 1-1: The modulation signal transmitted from each node to the receiving node and the positive and negative single tone signals are expressed as , , , its specific expression is: ； ； ； in, , Represents the broadband modulated signal transmitted by the node; express The carrier signal frequency of the transmitting nodes is the same as that of the Indicates the The frequency of the positive single-tone signal transmitted by the transmitting node, Indicates the The frequency of the negative single-tone signal transmitted by the transmitting node; represents the Doppler shift; , Respectively represent The propagation delay and initial phase from the transmitting node to the receiving node; Step 1-2: Take the first transmitting node as the reference node, The single tone frequency difference between the transmitting node and the first transmitting node is , the first node and the Each node transmits a positive single-tone signal to the receiving node, which is expressed as , , its specific expression is: ； ； Step 1-3: The specific expression of the received signal at the receiving node is: ； Step 1-4: If the first transmitting node is used as a reference, the The phase difference between the transmitting node and the first transmitting node is: 。 9. The method for coherently synthesizing distributed node broadband signal transmission assisted by multi-tone signals according to claim 8, characterized in that: The method of extracting the received multi-tone signal at the receiving node by down-conversion and low-pass filtering specifically includes the following sub-steps: down-converting and low-pass filtering the multi-tone signal received at the receiving node in sequence, and decoupling the zero-frequency single-tone signal to obtain the following: ； ； ； 。 10. The multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis method according to claim 9, characterized in that: The decoupled multi-tone signal estimation The phase difference and time difference between the transmitting nodes specifically include the following sub-steps: Step 3-1: If the signal and Multiplying together, we get : ； Step 3-2: Taking the first transmitting node as a reference, and Multiplying the conjugate of , we get: ； Step 3-3: The estimated phase difference between the transmitting node and the first transmitting node is: ;in, Indicates the phase to be solved; Step 3-4: Transmit the signal The conjugate of Multiplying together, we get : ； Step 3-5: Using the first transmitting node as a reference, transmit the signal The conjugate of Multiplying together, we get : ； Step 3-6: and Multiplying them, we get: ； Step 3-7: The estimated time difference between the transmitting node and the first transmitting node is: 。 11. The multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis method according to claim 10, characterized in that: The tracking and prediction by loop filtering specifically includes the following sub-steps: Step 4-1: Loop filtering Track the moment The phase difference between the first transmitting node and the first transmitting node is: ； ； in, , , For experience value, , represents the noise bandwidth, is the update period of the loop filter; , , Respectively indicate time Phase difference, loop filtering output results and phase difference prediction results; Step 4-2: Loop filtering Track the moment The time difference between the first transmitting node and the first transmitting node is: in, , , Respectively indicate time The phase difference, loop filtering output and time difference prediction results.

12. The multi-tone signal-assisted distributed node broadband signal transmission coherent synthesis method according to claim 11, characterized in that: The method of pre-compensating the time difference between nodes by delay filtering at the transmitting node and pre-compensating the phase difference between nodes to ensure the maximization of the coherent synthesis gain of the broadband signal transmission specifically includes the following sub-steps: Step 5-1: Estimation results of phase difference and time difference 、 Feedback to the transmitting node, compensated by the delay filter The time difference between the transmitting node and the first transmitting node is expressed as: ； ； in, represents a continuous time-delay filter, represents the cutoff frequency of the continuous domain; When processing in the discrete domain, the corresponding time delay filter is: ； in, represents the normalized cutoff frequency in the discrete domain, , is the sampling rate; Indicates the delay amount, ; Indicates the order of the delay filter; Step 5-2: After phase pre-compensation, the coherent synthesis signal at the receiving node C is: ； Step 5-3: Calculation The gain and efficiency of the coherent synthesis of the transmitting nodes are: ； 。

Images