CN105323029B - Acoustic underwater communication link distance, speed clock synchronization based on a dynamic - Google Patents

Acoustic underwater communication link distance, speed clock synchronization based on a dynamic Download PDF

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CN105323029B
CN105323029B CN201510771241.0A CN201510771241A CN105323029B CN 105323029 B CN105323029 B CN 105323029B CN 201510771241 A CN201510771241 A CN 201510771241A CN 105323029 B CN105323029 B CN 105323029B
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node
synchronization
signal
clock
time
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CN105323029A (en
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张友文
孙大军
李想
刘璐
范巍巍
刘衍超
王鹏
勇俊
刘鑫
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哈尔滨工程大学
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Abstract

本发明涉及水声通信领域,具体涉及基于声链路测距、测速的水声通信动态时钟同步方法。 The present invention relates to underwater acoustic communications, and in particular relates to a synchronization method for underwater acoustic communications link distance, speed of dynamic clock. 本发明包括:通信节点B根据高精度时钟驱动产生的周期为T的脉冲中断;通信节点A在T2时刻接收到B节点的同步配置信号a′;B节点在T4时刻接收到A节点在T3时刻发送的同步请求信号b′后;A节点在T6时刻接收到B节点的同步应答信号c′;B节点依据自身计算获得的时钟偏差和A节点计算获得的时钟偏差。 The present invention comprises: a communication interruption Node B accurately based on the cycle of the clock driven pulse generating T; a communication node A receives a synchronization signal configuration of a node B at time T2 '; Node B receives Node A at time T4 at time T3 synchronization request transmitted signal b 'after; a at time T6, node synchronization response signal receiving node c B'; B by node clock bias and clock bias node a itself obtained by calculation obtained by calculation. 本发明利用脉冲对互协方差算法估计节点间的相对运动速度,补偿由于节点间相对运动导致的双程传播时延不对等的情况,提高了运动条件下节点间的时钟同步精度,在相对运动速度在5节的条件下,时钟同步精度可以达到1毫秒以下。 The present invention, by pulse the relative velocity between the cross-covariance estimation algorithm nodes, not compensate for such relative movement results in the case of the inter-node round-trip propagation delay, improve the accuracy of the clock synchronization between nodes under the conditions of motion, a relative movement 5 at speed, the clock synchronization accuracy of up to 1 millisecond or less.

Description

基于声链路测距、测速的水声通信动态时钟同步方法 Acoustic underwater communication link distance, speed clock synchronization based on a dynamic

技术领域 FIELD

[0001] 本发明涉及水声通信领域,具体涉及基于声链路测距、测速的水声通信动态时钟同步方法。 [0001] The present invention relates to the field of underwater acoustic communications, particularly relates to clock synchronization method of dynamic acoustic underwater communication link distance, based on the velocity.

背景技术 Background technique

[0002] 在水下传感器网络中,节点间的同步性能是影响网络效能以及保证数据同步传输的一个重要因素。 [0002] In the underwater sensor network synchronization performance between nodes and network performance impact is an important factor to ensure synchronous data transfer. 在基于传感器网络的目标探测应用场合中,一方面,将不同网络中不同传感器节点感知到的数据或结果进行融合检测,网络检测性能严重依赖于节点数据的同步时间戳;另一方面,网络系统只有依赖统一的时间基准才有效地协同工作而避免不必要的数据传输碰撞而引发的额外能量损耗及网络吞吐量损失。 In applications where target detection based on the sensor network, on the one hand, the different sensor nodes of different network data sensed or detected result of the integration, the detection performance depends heavily on network synchronization timestamp of node data; on the other hand, the network system only rely on a uniform time reference was to work together effectively and avoid unnecessary data transmission collision caused by additional energy loss and network throughput loss. 目前有许多应用于无线网络的时钟同步协议,这些协议提供了很高的时钟同步精度,通过采用复杂的算法来减少同步误差,且考虑了信息在非物理信道中的延时,但在协议设计时,大都假设信道中的传播时延可以忽略不计,由于无线电波的即时传播特性,这些假设是合理的。 There are many clock synchronization protocol used in wireless networks, these protocols provide high clock synchronization accuracy, by using complex algorithms to reduce the synchronization error, and in view of the delay information in a non-physical channel, but in the protocol design , the propagation delay is assumed that most channels is negligible, since the propagation characteristics of radio waves instantly, which is a reasonable assumption. 在水下,无线电波的传播距离是非常有限的,而水声通信为水下节点的时钟同步提供了一个可选的方案。 In water, the propagation distance of radio waves is very limited, and underwater acoustic communication node clock synchronization provides an alternative solution. 《Time synchronization for high latency acoustic networks〉〉中指出水下节点时钟同步精度低的最大原因是由于声波的低速传播特性,提出了两个阶段的时钟同步算法TSHL:第一阶段通过发送若干个消息包来估计时钟漂移斜率;第二阶段通过两次信息交互来估计时钟偏差。 "Time synchronization for high latency acoustic networks >> noted that the biggest reason for the low underwater node clock synchronization accuracy is low due to the characteristics of propagation, the clock synchronization algorithm proposed TSHL two phases: the first phase by transmitting a plurality of packets estimated clock drift slope; second phase clock bias is estimated through information interaction twice. 该算法假设同步时节点在同步过程中是相对静止的,即传播时延是恒定的,这限制了其在水下移动节点场合的应用。 The algorithm assumes that a node synchronization in the synchronization process is relatively static, i.e., a constant propagation delay, which limits its application in underwater mobile node occasions. 王怿等人的《水下传感网时钟同步与节点定位研究》通过增大TSHL算法的同步信号的间隔来减少信号发送的数量,从而减少能量消耗。 Yi Wang et al., "Underwater sensor network clock synchronization and Orientation of the node" to reduce the number of signal transmission by increasing the interval of the synchronizing signal TSHL algorithm, thereby reducing power consumption. Tri-Message (长时延低耗网络的轻量级时间同步协议)在TSHL协议的基础上对信息交互的开销进行了进一步的削减,在一次同步过程中只需要交换3次彳目息,但仍是在节点相对静止的前提条件下。 Tri-Message (lightweight long-latency and low consumption of network time synchronization protocol) on the basis of TSHL agreement on information exchange on the overhead carried out further cuts in the first synchronization exchange only three left foot head interest rates, but still under the prerequisite node relatively static. 水下节点时钟同步的关键问题在于如何正确估计声信号在信道中的传播时延,受洋流、节点自身运动等因素影响,传播时延变得难以预测,这也是水下节点时钟同步的困难所在。 Underwater node clock synchronization key issue is how to correctly estimate the acoustic signal propagation delay in the channel, by the ocean currents, node affect their exercise and other factors, the propagation delay becomes difficult to predict, and this is where the underwater node clock synchronization difficulties .

发明内容 SUMMARY

[0003] 本发明的目的是为了提供一种解决传统的TSHL时钟同步算法及其演化算法在通信节点存在相对运动时同步精度下降的问题的基于声链路测距、测速的水声通信动态时钟同步方法。 [0003] The object of the present invention is to provide a clock synchronization algorithm TSHL its evolution algorithm to solve the traditional problems of synchronization accuracy is lowered when there is relative movement in a communication node for underwater acoustic communications link distance, speed of dynamic clock synchronization method.

[0004] 本发明的目的是这样实现的: [0004] The object of the present invention is implemented as follows:

[0005] 本发明包括:(1)通信节点B根据高精度时钟驱动产生的周期为T的脉冲中断,发射同步配置信号a、同时记录本地发射时刻T1;其中同步配置信号a'内含有前后联接的两个线性调频信号组成的脉冲对;通信节点B即为B节点; [0005] The present invention comprises: (1) B is a communication node in accordance with a pulse period T of the interrupt generated by the driving high-precision clock, transmitting a synchronization signal configuration, while recording the local time of transmission Tl; configuration wherein the synchronization signal comprises a longitudinal coupling 'of the composition of the two chirp signal pulse; communication node B is the node B;

[0006] (2)通信节点六在!^时刻接收到B节点的同步配置信号a',并求解得到节点间的相对运动速度V; [0006] (2) at the six communication node receiving timing synchronization ^ B signal configuration node a ', and solved to obtain the relative velocity V between the nodes!;

[0007] 通信节点A即为A节点;A节点在T3时刻,将含有T2&T3两个时刻的信息进行编码后发送同步请求信号I/给B节点,B节点根据测得的脉冲对的频偏f△计算多普勒压缩因子,根据多普勒压缩因子同步请求信号M进行线性重采样,由B节点将重采样后的信号进行后续的解调及译码,得到含有T2&T3两个时刻的信息; [0007] The communication node A is the node A; A node at time T3, containing the T2 & amp; the information T3 two time encoding transmission synchronization request signal I / to a Node B, Node B according to the measured pulse frequency pairs partial f △ calculating the Doppler compression factor, the compression factor based on the Doppler synchronization request signal M to linear resampling, the signal is re-sampled for subsequent demodulation and decoding by the node B, to give containing T2 & amp; T3 two time information;

[0008] (3) B节点在Τ4时刻接收到A节点在T3时刻发送的同步请求信号1/后,在!^时刻再次发送含有T4、I^t刻的信息进行编码后,发送同步应答信号夕给A节点; Synchronization request [0008] (3) B node receives A node Τ4 time transmitted at time T3 signal 1 /, the at! ^ Time retransmission containing T4, the information I ^ t engraved encoding, transmitting a synchronization response signal Xi to node A;

[0009] (4) A节点在T6时刻接收到B节点的同步应答信号c7,假设在整个同步过程中节点间的相对运动速度保持不变,声波在水中传播的平均声速为c;设在T1时亥IjB节点与A节点的相对距离为L1,根据B节点获得的四个时刻值T1、T2、T3、T4及相对运动速度V得到 [0009] (4) A node receives the synchronization response signal Node B in time T6 C7, assuming the relative velocity between nodes remain constant during the synchronization process, the average speed of sound in the propagation of acoustic waves in water C; provided T1 when the relative distance Hai IjB node a node is L1, V obtained according to the four time value T1 B node obtained, T2, T3, T4 and the relative velocity

Figure CN105323029BD00051

[0011]其中,L^T2时刻B节点与A节点的相对距离,L4是T4时刻B节点与A节点的相对距离; [0011] wherein, L ^ Node B and the relative distance of the node A at time T2, L4 is the relative distance in time T4 and the node A node B;

Figure CN105323029BD00052

为B节点要估计的时钟偏差; Node B is to be estimated clock bias;

[0012] 求出固定时钟偏差,和相对斜距 [0012] determined clock offset is fixed, and an opposite slant range

Figure CN105323029BD00053

,即 , which is

Figure CN105323029BD00054

Figure CN105323029BD00055

[0015] 根据四个时刻值T3、T4、T5、T6及相对运动速度V,得到A节点的时钟偏差 [0015] T3, T4, T5, T6 and the relative velocity V according to the value four time, clock bias node A to give

Figure CN105323029BD00056

[0016] (5) B节点依据自身计算获得的时钟偏差 [0016] The clock offset (5) B obtained by the calculation based on their node

Figure CN105323029BD00057

和A节点计算获得的时钟偏差 A node calculation and clock bias obtained

Figure CN105323029BD00058

计算两者差值,若差值小于所设门限,则认为该时钟偏差计算正确,A节点能够调整时钟与节点B 对齐;否则认为时钟估计有误,返回步骤(1)再次进行同步。 Calculating difference between the two, if the difference is less than the set threshold, the clock offset calculation is considered correct, A node can align with the Node B to adjust the clock; clock estimation error that otherwise returns to step (1) to synchronize again.

[0017] 所述步骤(2)中通信节点六在!^时刻接收到B节点的同步配置信号a、并求解得到节点间的相对运动速度V: [0017] The step (2) is six at a communication node receiving timing synchronization ^ a B signal configuration node, and solved to obtain the relative velocity V between the nodes!:

[0018] (2.1)A节点用本地存储的线性调频信号d'与接收到B节点的同步配置信号a'进行匹配滤波,对匹配滤波后的输出信号取绝对值以后通过一个低通滤波器,得到匹配以后的信号包络低通滤波器的带宽与同步配置信号带宽相等; [0018] (2.1) A node 'and the reception of the synchronization signal Node B is arranged a' chirp matched filtering with a locally stored signal d, the output signal of the absolute value after matched filtering by a low-pass filter, after matching the obtained signal envelope and the bandwidth of the low pass filter of bandwidth equal to the synchronizing signal configuration;

[0019] (2.2)对信号包络^进行门限判决,对超过判决门限的信号包络^进行鉴别,如果满足:在信号包络^上出现与本地存储线性调频信号cT长度相等且高度相等或者相近的两个相关峰,且相关峰高度与旁瓣包络均值比超过设计门限,而且相关峰3dB宽度与同步配置信号的带宽倒数相等或者相近;截取获得同步配置信号a% [0019] (2.2) of the signal envelope ^ for threshold decision, in excess of the decision threshold signal envelope ^ identification, if satisfied: it appears equal to a locally stored chirp signal cT length and a height equal to or a signal envelope ^ two correlation peaks close, and the height of the correlation peak to average ratio sidelobe envelope exceeds the design threshold, and a correlation peak width of 3dB bandwidth of the synchronization signal reciprocal configuration equal or similar; taken acquires synchronization signal arranged a%

[0020] (2.3)对截取获得的同步配置信号a',采用互协方差计算脉冲对的频偏f△,从而得到节点间相对运动速度V。 [0020] (2.3) arranged synchronization signal is taken to obtain a ', using the frequency deviation f △ cross-covariance calculation of pulse pairs, whereby the relative velocity between nodes V.

[0021] 所述步骤(2.3)得到节点间相对运动速度V是通过互相关协方差法求解得到的: [0021] The step (2.3) to obtain the relative velocity V between the nodes is achieved by cross-correlation method to solve the covariance obtained:

[0022] B节点在T1时刻发送时的域数据信号为X (k),它的复通频带等效信号为 [0022] B domain node at a time T1 when the data signal is transmitted as X (k), which is equivalent to the complex passband signal

[0023] s (k) =x (k) exp (2 Xpi X j XftxXkXTs) [0023] s (k) = x (k) exp (2 Xpi X j XftxXkXTs)

[0024] 式中,ftx为发送的载波频率;pi为π,j为虚部;k为采样点下标;TS为采样间隔; [0024] wherein, ftx is the transmission carrier frequency; PI is π, j is an imaginary unit; subscript K sampling points; the TS is the sampling interval;

[0025] 在接收端,S卩A节点,在忽略噪声的情况下,复的基带信号为 [0025] At the receiving end, S Jie A node, in a case where the noise is ignored, the complex baseband signal is

Figure CN105323029BD00061

[0027] 式中,frx为接收的载波频率;为频偏,= ftx_frx; ε =NhTs = N (ftx_frx) Ts为归一化载波频率偏差,N为采样点数; [0027] wherein, frx of the received carrier frequency; frequency deviations, = ftx_frx; ε = NhTs = N (ftx_frx) Ts is the normalized carrier frequency deviation, N is the number of sampling points;

[0028] 两个线性调频信号的总长度为L,中间变量 [0028] The total length of the two chirp signals is L, an intermediate variable

Figure CN105323029BD00062

[0030] 其中,D为截取的单个信号为长度;f (·)为r (·)转置; [0030] where, D is the length of a single signal is taken; f (·) of r (·) transposition;

[0031] 得到归一化载波频率偏差的估计值为 [0031] to obtain a normalized value of the estimated carrier frequency offset

Figure CN105323029BD00063

[0033] 其中,ZR为R的相位; [0033] wherein, ZR phases R;

[0034] 根据归一化载波频率偏差ε =Nfds = N (ftx_frx) Ts求得h; [0034] The normalized carrier frequency offset ε = Nfds = N (ftx_frx) Ts obtained H;

[0035] 依据多普勒原理,估算出同步周期内两个通信节点间的相对速度V; [0035] based on the Doppler principle, the estimated relative velocity between the two communication nodes V synchronization period;

Figure CN105323029BD00064

[0037] 所述步骤(2.3)的归一化载波频率偏差估计值ε的估计范围 [0037] The step (2.3) the normalized carrier frequency offset estimation range of the estimation value ε

Figure CN105323029BD00065

[0038] 本发明的有益效果在于: [0038] Advantageous effects of the present invention:

[0039] 本发明利用脉冲对互协方差算法估计节点间的相对运动速度,补偿由于节点间相对运动导致的双程传播时延不对等的情况,提高了运动条件下节点间的时钟同步精度,在相对运动速度在5节的条件下,时钟同步精度可以达到1毫秒以下。 [0039] The present invention, by pulse relative velocity between the node cross-covariance variance estimation algorithm, to compensate the two-way propagation delay between nodes does not like the case of relative movement results in improved accuracy of the clock synchronization between nodes under the conditions of motion, the relative velocity at 5, the clock synchronization accuracy of up to 1 millisecond or less.

附图说明 BRIEF DESCRIPTION

[0040] 图1为基于声链路测距、测速的时钟同步方法示意图。 [0040] FIG. 1 is a schematic method for clock synchronization link sound ranging, based on the velocity.

具体实施方式 Detailed ways

[0041] 下面结合附图对本发明做进一步描述。 [0041] The following figures further described in conjunction with the present invention.

[0042] 基于声链路测距、测速的水声通信动态时钟同步方法,涉及水声通信领域,具体涉及水声通信动态时钟同步方法。 [0042] Acoustic underwater communication link distance, speed dynamic clock synchronization based, relates to underwater acoustic communications, and in particular relates to dynamic acoustic communication method for clock synchronization. 为了解决传统的TSHL时钟同步算法及其演化算法在通信节点存在相对运动时同步精度下降的问题。 To solve the problem when a conventional TSHL synchronization accuracy clock synchronization algorithm and its evolutionary algorithm there is relative motion communication node lowered. 本发明通过通信节点B发射带有时刻信息的同步配置信号a';通信节点A对同步配置信号a'进行匹配滤波,得到匹配以后的信号包络^,截取获得同步配置信号a、采用互协方差计算脉冲对的频偏f△,从而得到节点间相对运动速度V;然后根据节点B和节点A相互发送带有时刻信息的信号,分别求出B节点的时钟偏差見和A节点的时钟偏差£;:,并计算两者差值,当差值小于所设门限,则A节点能够调整时钟与节点B对齐,完成同步。 The present invention is transmitted through the communication with the Node B synchronization configuration time information signal a '; A communication node for configuration synchronization signal a' matched filtering, to obtain the signal envelope after matching ^, taken configured to obtain synchronization signals a, using the cross-covariance calculating the variance of the frequency offset f △ pulse, resulting in a relative velocity V between the nodes; then sends a signal to each other according to the time information with nodes B and a, respectively, to obtain clock bias clock bias node B and node a, see £;:, and calculates the difference between the two, when the difference is smaller than the set threshold, it is possible to adjust the clock node A and the node B is aligned, complete synchronization. 本发明适用于水声通信动态时钟的同步。 The present invention is applicable to synchronous dynamic acoustic communication clock.

[0043] 基于声链路测距、测速的水声通信动态时钟同步方法,包括下述步骤: [0043] The clock synchronization method of dynamic acoustic underwater communication link distance, based on speed, comprising the steps of:

[0044] 步骤1、通信节点B根据高精度时钟驱动产生的周期为T的脉冲中断,发射同步配置信号a、同时记录本地发射时刻T1;其中同步配置信号a'内含有前后联接的两个线性调频信号组成的脉冲对,脉冲对用于帧信号的鉴别及相对运动速度V的估计;通信节点B即为B节占. [0044] Step 1, the communication node B according to the clock period high-precision drive pulse T generated interrupts, transmitting a synchronization signal configuration, while recording the local time of transmission Tl; configuration wherein the synchronization signal comprises a linear coupling of the two front 'of pulse frequency modulated signal composed of a pulse frame signal used for estimation and identification of the relative velocity V; communication node B is the section B accounted for.

[0045] 步骤2、通信节点八在!^时刻接收到B节点的同步配置信号a ',并求解得到节点间的相对运动速度V; [0045] Step 2, eight communication nodes at the time of receiving the synchronization ^ B signal configuration node a ', and solved to obtain the relative velocity V between the nodes!;

[0046] 通信节点A即为A节点;A节点在T3时刻,将含有T2&T3两个时刻的信息进行编码后发送同步请求信号M给B节点,B节点根据测得的脉冲对的频偏f△计算多普勒压缩因子,根据多普勒压缩因子同步请求信号M进行线性重采样,由B节点将重采样后的信号进行后续的解调及译码,得到含有T2&T3两个时刻的信息; [0046] A communication node is the node A; A node at time T3, containing the T2 & amp; T3 after the two time information is coded synchronization request signal transmitted to the M Node B, Node B according to the deviation of the measured pulse f △ calculating the Doppler compression factor, factor synchronization request signal M to linear resampling, the signal is resampled by a node B for subsequent demodulation and decoding, to obtain the Doppler containing compressed T2 & amp; T3 two time Information;

[0047] 步骤3、Β节点在Τ4时刻接收到A节点在T3时刻发送的同步请求信号1/后,在T5时刻再次发送含有T4、I^t刻的信息进行编码后,发送同步应答信号夕给A节点; [0047] Step 3, Β node Τ4 timing of receiving the A node synchronization request signal transmitted 1 /, the transmission again at time T5 at time T3 containing T4, the information I ^ t engraved encoding, transmitting a synchronization response signal Xi A given node;

[0048] 步骤4、A节点在T6时刻接收至IjB节点的同步应答信号c7,假设在整个同步过程中节点间的相对运动速度保持不变,声波在水中传播的平均声速为c (声速可用声速梯度仪事先在该海域测量获得,同时假设同步过程中声波传播的路径和AUV运动的路径夹角近似为零, 这个假设在较远距离通信时是合理的);设在T1时刻B节点与A节点的相对距离为L1,根据B节点获得的四个时刻值T1、T2、T3、T4及相对运动速度V得到 [0048] Step 4, A node receives a response to the synchronization timing signal T6 IjB C7 node, assuming the relative velocity between nodes remain constant during the synchronization process, the average speed of sound in the propagation of acoustic waves in water C (the speed of sound the speed of sound available gradiometer measurement is obtained in advance in the area, while assuming the synchronization process path acoustic wave propagation path of movement of the AUV and approximately zero angle, when this assumption is reasonable compared with the communication distance); node B is provided at time T1 and a nodes is the relative distance L1, V obtained according to the four time value T1 B node obtained, T2, T3, T4 and the relative velocity

Figure CN105323029BD00071

[0050] 其中,!^是!^时刻B节点与A节点的相对距离,L4是T4时刻B节点与A节点的相对距离; ! [0050] wherein ^ ^ is the relative time from the node B to the node A, L4 is the relative distance in time T4 Node B and node A!;

Figure CN105323029BD00072

为B节点要估计的时钟偏差; Node B is to be estimated clock bias;

[0051] 由以上方程组⑴可求出固定时钟偏差和相对斜距 [0051] From the above equations ⑴ fixed clock can be derived from the deviation and relative swash

Figure CN105323029BD00073

,即 , which is

Figure CN105323029BD00074

Figure CN105323029BD00075

[0054] 根据四个时刻值T3、T4、T5、T6及相对运动速度V,可以得到A节点的时钟偏差;; [0054] T3, T4, T5, T6 and the relative velocity V, the node A can be obtained according to the clock offset value four time ;;

[0055] 步骤5、B节点依据自身计算获得的时钟偏差和A节点计算获得的时钟偏差^,计算两者差值,若差值小于所设门限,则认为该时钟偏差计算正确,A节点能够调整时钟与节点B对齐;否则认为时钟估计有误,返回步骤1再次进行同步。 [0055] Step 5, B is calculated based on Node A and node clock skew clock offset obtained by calculation itself obtained ^, calculated difference between the two, if the difference is less than the set threshold, it is considered that the clock bias is calculated correctly, the node A can be aligned with the node B to adjust the clock; clock estimation error that otherwise, return to step 1 for re-synchronization.

[0056] [0056]

具体实施方式一:结合图1说明本实施方式,基于声链路测距、测速的水声通信动态时钟同步方法,包括下述步骤: A specific embodiment: FIG. 1 explained in conjunction with the present embodiment, the clock synchronization method of dynamic acoustic underwater communication link distance, based on speed, comprising the steps of:

[0057] 步骤1、通信节点B根据高精度时钟驱动产生的周期为T的脉冲中断,发射同步配置信号a、同时记录本地发射时刻T1;其中同步配置信号a'内含有前后联接的两个线性调频信号组成的脉冲对,脉冲对用于帧信号的鉴别及相对运动速度V的估计;通信节点B即为B节占. [0057] Step 1, the communication node B according to the clock period high-precision drive pulse T generated interrupts, transmitting a synchronization signal configuration, while recording the local time of transmission Tl; configuration wherein the synchronization signal comprises a linear coupling of the two front 'of pulse frequency modulated signal composed of a pulse frame signal used for estimation and identification of the relative velocity V; communication node B is the section B accounted for.

[0058] 步骤2、通信节点六在!^时刻接收到B节点的同步配置信号a',并求解得到节点间的相对运动速度V; [0058] Step 2, the six communication node receiving timing synchronization ^ B signal configuration node a ', and solved to obtain the relative velocity V between the nodes!;

[0059] 通信节点A即为A节点;A节点在T3时刻,将含有T2&T3两个时刻的信息进行编码后发送同步请求信号M给B节点,B节点根据测得的脉冲对的频偏f△计算多普勒压缩因子,根据多普勒压缩因子同步请求信号M进行线性重采样,由B节点将重采样后的信号进行后续的解调及译码,得到含有T2&T3两个时刻的信息; [0059] A communication node is the node A; A node at time T3, containing the T2 & amp; T3 after the two time information is coded synchronization request signal transmitted to the M Node B, Node B according to the deviation of the measured pulse f △ calculating the Doppler compression factor, factor synchronization request signal M to linear resampling, the signal is resampled by a node B for subsequent demodulation and decoding, to obtain the Doppler containing compressed T2 & amp; T3 two time Information;

[0060] 步骤3、Β节点在Τ4时刻接收到A节点在T3时刻发送的同步请求信号1/后,在T5时刻再次发送含有T4、I^t刻的信息进行编码后,发送同步应答信号夕给A节点; [0060] Step 3, Β node Τ4 timing of receiving the A node synchronization request signal transmitted 1 /, the transmission again at time T5 at time T3 containing T4, the information I ^ t engraved encoding, transmitting a synchronization response signal Xi A given node;

[0061] 步骤4、A节点在T6时刻接收到B节点的同步应答信号c7,假设在整个同步过程中节点间的相对运动速度保持不变,声波在水中传播的平均声速为c (声速可用声速梯度仪事先在该海域测量获得,同时假设同步过程中声波传播的路径和AUV运动的路径夹角近似为零, 这个假设在较远距离通信时是合理的);设在T1时刻B节点与A节点的相对距离为L1,根据B节点获得的四个时刻值T1、T2、T3、T4及相对运动速度V,得到 [0061] Step 4, A at time T6, node receiving the synchronization response signal C7 Node B, assuming the relative velocity between nodes remain constant during the synchronization process, the average speed of sound in the propagation of acoustic waves in water C (the speed of sound the speed of sound available gradiometer measurement is obtained in advance in the area, while assuming the synchronization process path acoustic wave propagation path of movement of the AUV and approximately zero angle, when this assumption is reasonable compared with the communication distance); node B is provided at time T1 and a nodes is the relative distance L1, T1 B in accordance with the value of the time four nodes obtained, T2, T3, T4 and the relative velocity V, to give

Figure CN105323029BD00081

[0063] 其中,!^是!^时刻B节点与A节点的相对距离,L4是T4时刻B节点与A节点的相对距离; ! [0063] wherein ^ ^ is the relative time from the node B to the node A, L4 is the relative distance in time T4 Node B and node A!;

Figure CN105323029BD00082

为B节点要估计的时钟偏差; Node B is to be estimated clock bias;

[0064] 由以上方程组⑴可求出固定时钟偏差,和相对斜距 [0064] From the above equations can be derived ⑴ fixed clock skew, slant range and relative

Figure CN105323029BD00083

,即 , which is

Figure CN105323029BD00084

Figure CN105323029BD00085

[0067] A节点可以根据四个时刻值T3、T4、T5、T6及相对运动速度V,得到A节点的时钟偏差 [0067] A node may be a value according to the four time moments T3, T4, T5, T6 and the relative velocity V, the node A to obtain the clock offset

Figure CN105323029BD00086

[0068] 步骤5、Β节点依据自身计算获得的时钟偏差 [0068] Step 5, Β node itself based clock offset calculation obtained

Figure CN105323029BD00087

和A节点计算获得的时钟偏差 A node calculation and clock bias obtained

Figure CN105323029BD00088

计算两者差值,若差值小于所设门限,则认为该时钟偏差计算正确,A节点能够调整时钟与节点B对齐;否则认为时钟估计有误,返回步骤1再次进行同步。 Calculating difference between the two, if the difference is less than the set threshold, the clock offset calculation is considered correct, A node can align with the Node B to adjust the clock; clock estimation error that otherwise, return to step 1 for re-synchronization.

[0069] [0069]

具体实施方式二:本实施方式所述的步骤2中通信节点六在!^时刻接收到B节点的同步配置信号a、并求解得到节点间的相对运动速度V的具体步骤如下: DETAILED Embodiment 2: This embodiment of the six step 2 in the communication node receiving timing synchronization ^ a B signal configuration node, and solved to obtain the relative velocity V between the nodes specific steps are as follows!:

[0070] 步骤2.1 :A节点用本地存储的线性调频信号cT与接收到B节点的同步配置信号a' 进行匹配滤波,对匹配滤波后的输出信号取绝对值以后通过一个低通滤波器,得到匹配以后的信号包络低通滤波器的带宽与同步配置信号带宽相等; [0070] Step 2.1: A node receiving the locally stored chirp signal cT to the synchronous signal Node B is arranged a 'matched filtering on the matched filter output signal after the absolute value through a low pass filter, to give after the signal envelope matching the bandwidth of the low pass filter with a bandwidth equal to the synchronizing signal configuration;

[0071] 步骤2.2:对信号包络,进行门限判决,对超过判决门限的信号包络,进行鉴别, 如果满足:在信号包络^上出现与本地存储线性调频信号d'长度相等且高度相等或者相近的两个相关峰,且相关峰高度与旁瓣包络均值比超过设计门限,而且相关峰3dB宽度与同步配置信号的带宽倒数相等或者相近;截取获得同步配置信号a% [0071] Step 2.2: signal envelope, a threshold decision on the signal envelope exceeds the decision threshold, identification, if satisfied: it appears equal to a locally stored chirp signal d 'length and a height equal to the signal envelope ^ or similar two correlation peaks, and correlation peak sidelobe height exceeds the design envelope to average ratio threshold, and a correlation peak width of 3dB bandwidth of the synchronization signal reciprocal configuration equal or similar; taken acquires synchronization signal arranged a%

[0072] 步骤2.3:对截取获得的同步配置信号a',采用互协方差计算脉冲对的频偏f △,从而得到节点间相对运动速度V。 [0072] Step 2.3: Configuring the synchronization signal is taken to obtain a ', using the frequency deviation f △ cross-covariance calculation of pulse pairs, whereby the relative velocity between nodes V.

[0073] 其它步骤和参数与具体实施方式一相同。 [0073] Other steps and parameters of a specific embodiment of the same embodiment.

[0074] [0074]

具体实施方式三:本实施方式中的步骤2.3得到节点间相对运动速度V是通过互相关协方差法求解得到的, DETAILED Embodiment 3: Step 2.3 of the present embodiment to obtain the relative velocity V between the nodes is achieved by cross-correlation method to solve the obtained covariance,

[0075] 具体步骤入下: [0075] into the following specific steps:

[0076] 通过采用互相关协方差方法对前后串联的线性调频信号的频偏进行估计,依据多普勒原理估算出同步周期内两个通信节点间的相对速度V,从而补偿同步周期内由于节点运动导致的双程传播时延的不对等,提高时钟同步的精度; [0076] By using the cross-correlation covariance method of linear frequency modulation of the frequency offset is estimated in tandem, to estimate the relative velocity V between two communicating nodes synchronization period based on the Doppler principle, whereby the synchronization period to compensate since the node two-way propagation delay caused by unequal movement to improve the accuracy of clock synchronization;

[0077] B节点在T1时刻发送时的域数据信号为X (k),它的复通频带等效信号为 [0077] B domain node at a time T1 when the data signal is transmitted as X (k), which is equivalent to the complex passband signal

[0078] s (k) =x (k) exp (2 Xpi X j XftxXkXTs) (4) 式中,ftx为发送的载波频率;pi为π,j为虚部;k为采样点下标;Ts为采样间隔; [0078] s (k) = x (k) exp (2 Xpi X j XftxXkXTs) (4) where, ftx carrier frequency transmitted; PI is π, j is an imaginary unit; K sampling points subscript; Ts of sampling interval;

[0079] 在接收端,S卩A节点,在忽略噪声的情况下,复的基带信号为 [0079] At the receiving end, S Jie A node, in a case where the noise is ignored, the complex baseband signal is

Figure CN105323029BD00091

[0081] 式中,frx为接收的载波频率;f λ为频偏,f λ = f tx_frx; ε =Nf ATs = N (f tx_frx) Ts为归一化载波频率偏差,N为采样点数; [0081] wherein, frx of the received carrier frequency; f λ is the frequency offset, f λ = f tx_frx; ε = Nf ATs = N (f tx_frx) Ts is the normalized carrier frequency deviation, N is the number of sampling points;

[0082] 定义两个线性调频信号的总长度为L,定义中间变量 [0082] The total length of the two chirp signals is defined as L, the definition of intermediate variables

Figure CN105323029BD00092

[0084] 其中,D为截取的单个信号为长度;f ( ·)为r ( ·)转置; [0084] where, D is the length of a single signal is taken; f (·) of r (·) transposition;

[0085] 有公式⑶得到归一化载波频率偏差的估计值为 [0085] Equation ⑶ have been estimated as a normalized carrier frequency offset

Figure CN105323029BD00093

[0087] 其中,ZR为R的相位; [0087] wherein, ZR phases R;

[0088] 根据公式⑵和归一化载波频率偏差ε =Nfds = N (ftx_frx) Ts可以求得h; [0088] According to the formula ⑵ and normalized carrier frequency offset ε = Nfds = N (ftx_frx) Ts H can be determined;

[0089] 依据多普勒原理,根据公式⑶估算出同步周期内两个通信节点间的相对速度V; [0089] based on the Doppler principle, according to the formula ⑶ estimated relative velocity V between two communicating nodes synchronization period;

[0090] [0090]

Figure CN105323029BD00101

[0091] 其它步骤和参数与具体实施方式二相同。 [0091] Other steps and parameters with the same two specific embodiments.

[0092] 具体实施方式四:本实施方式所述步骤2.3所述的归一化载波频率偏差估计值ε的估计范围 [0092] DETAILED DESCRIPTION four: the present embodiment, the step of normalizing the carrier frequency offset estimation range of the estimation value ε 2.3

Figure CN105323029BD00102

Claims (4)

1. 基于声链路测距、测速的水声通信动态时钟同步方法,其特征在于,包括下述步骤: (1) 通信节点B根据高精度时钟驱动产生的周期为T的脉冲中断,发射同步配置信号a、 同时记录本地发射时刻T1;其中同步配置信号a'内含有前后联接的两个线性调频信号组成的脉冲对;通信节点B即为B节点; (2) 通信节点六在!^时刻接收到B节点的同步配置信号a',并求解得到节点间的相对运动速度V; 通信节点A即为A节点;A节点在T3时刻,将含有T2&T3两个时刻的信息进行编码后发送同步请求信号M给B节点,B节点根据测得的脉冲对的频偏f△计算多普勒压缩因子,根据多普勒压缩因子同步请求信号M进行线性重采样,由B节点将重采样后的信号进行后续的解调及译码,得到含有T2&T3两个时刻的信息; (3) B节点在Τ4时刻接收到A节点在T3时刻发送的同步请求信号1/后,在T5时刻再次 1. The clock synchronization method of dynamic acoustic underwater communication link distance, based on speed, characterized by comprising the steps of: (1) The communication node B precision clock period T of the driving pulse generated interruption, transmit a synchronization configuration signal a, while recording the time Tl local transmitter; configuration wherein the synchronization signal comprises a pulse consisting of two chirp signals coupled to the front 'of; communication node B is the node B; (2) six communications node at time ^! receipt of the synchronization configuration signal node B a ', and solved to obtain the relative velocity V between the nodes; communication node a is the node a; a node at time T3, containing the T2 & amp; transmit the information T3 two time encoding after synchronization request signal to the M node B, node B calculates the Doppler frequency deviation f △ compression factor in accordance with the measured pulse pairs, according to the synchronization request signal Doppler compression factor M to linear resampling, a node B resampled subsequent signal demodulating and decoding, to obtain comprising T2 & amp; T3 two time information; (3) B a node receives the node synchronization request transmitted at time T3 signal 1 / Τ4 after time again at time T5 发送含有T4、I^t刻的信息进行编码后,发送同步应答信号夕给A节点; ⑷A节点在T6时刻接收到B节点的同步应答信号c7,在整个同步过程中节点间的相对运动速度保持不变,声波在水中传播的平均声速为c;设在T1时刻B节点与A节点的相对距离为L1,根据B节点获得的四个时刻值T1、T2、T3、T4及相对运动速度V得到 Transmitting containing T4, the information I ^ t engraved encoding, transmitting a synchronization response signal Xi to the node A; ⑷A node receives the synchronization response signal Node B c7 at time T6, the relative velocity between the nodes held in the entire synchronization process constant average speed of sound in the propagation of acoustic waves in water C; relative distance is provided at the time T1 node B and node a is L1, according to the value four time T1 node B obtained, T2, T3, T4 and the relative velocity V to give
Figure CN105323029BC00021
其中,!^是!^时刻B节点与A节点的相对距离,L4是T4时刻B节点与A节点的相对距离; ! Wherein ^ ^ is the relative time from the node B to the node A, L4 is the relative distance in time T4 Node B and node A!;
Figure CN105323029BC00022
为B节点要估计的时钟偏差; 求出固定时钟偏差和相对斜距 Node B is to be estimated clock bias; fixed clock is obtained from the deviation and relative swash
Figure CN105323029BC00023
,即 , which is
Figure CN105323029BC00024
Figure CN105323029BC00025
根据四个时刻值T3、T4、T5、T6及相对运动速度V,得到A节点的时钟偏差; (5) B节点依据自身计算获得的时钟偏差i;^PA节点计算获得的时钟偏差^,计算两者差值,若差值小于所设门限,则认为该时钟偏差计算正确,A节点能够调整时钟与节点B对齐;否则认为时钟估计有误,返回步骤(1)再次进行同步。 The four time value T3, T4, T5, T6 and the relative velocity V, to give clock bias node A; (5) B is calculated based on its own clock bias node i obtained; ^ PA clock bias node calculation obtained ^, calculated difference between the two, if the difference is less than the set threshold, the clock offset calculation is considered correct, A node can align with the node B to adjust the clock; clock estimation error that otherwise returns to step (1) to synchronize again.
2. 根据权利要求1所述的基于声链路测距、测速的水声通信动态时钟同步方法,其特征在于:所述步骤(2)中通信节点六在!^时刻接收到B节点的同步配置信号a',并求解得到节点间的相对运动速度V: (2.1) A节点用本地存储的线性调频信号cT与接收到B节点的同步配置信号a'进行匹配滤波,对匹配滤波后的输出信号取绝对值以后通过一个低通滤波器,得到匹配以后的信号包络低通滤波器的带宽与同步配置信号带宽相等; (2.2) 对信号包络,进行门限判决,对超过判决门限的信号包络,进行鉴别,如果满足:在信号包络^上出现与本地存储线性调频信号cT长度相等且高度相等或者相近的两个相关峰,且相关峰高度与旁瓣包络均值比超过设计门限,而且相关峰3dB宽度与同步配置信号的带宽倒数相等或者相近;截取获得同步配置信号a% (2.3)对截取获得的同步配置信号a',采 2. The method for clock synchronization dynamic acoustic underwater communication link distance, based on speed, wherein according to claim 1:! Said step (2) is six at a communication node receiving the Node B ^ timing synchronization configuration signal a ', and solved to obtain the relative velocity V between the nodes: (2.1) a node with a chirp signal cT stored locally with the received configuration synchronization signal node B is a' matched filtering, the output of the matched filter signal through a low-pass filter, an absolute value obtained after matching signal envelope after the low pass filter with a bandwidth equal to the bandwidth of the synchronization signal configuration; (2.2) of the signal envelope, a threshold decision of the decision threshold signal exceeds envelope identification, if satisfied: there are two correlation peaks is equal to a locally stored chirp signal cT length and a height equal to or close to the signal envelope ^ on, and the correlation peak height of the sidelobe envelope mean limit ratio exceeds design door and the 3dB width of the correlation peak with the synchronization signal, the reciprocal of the bandwidth of the configuration is equal or similar; taken acquires synchronization signal arranged a% (2.3) arranged on the synchronizing signal obtained taken a ', taken 互协方差计算脉冲对的频偏f△,从而得到节点间相对运动速度V。 The cross-covariance is calculated for the frequency offset f △ pulse, whereby the relative velocity between nodes V.
3. 根据权利要求2所述的基于声链路测距、测速的水声通信动态时钟同步方法,其特征在于:所述步骤(2.3)得到节点间相对运动速度V是通过互相关协方差法求解得到的: B节点在T1时刻发送时的域数据信号为X (k),它的复通频带等效信号为s (k) =x (k) exp (2 X pi X j X ftx X k X Ts) 式中,ftx为发送的载波频率;pi为π,j为虚部;k为采样点下标;Ts为采样间隔; 在接收端,即A节点,在忽略噪声的情况下,复的基带信号为 According to claim 2, the method for clock synchronization dynamic acoustic underwater communication link distance, based on speed, wherein: said step (2.3) to obtain the relative velocity V between the nodes is achieved by cross-correlation covariance solving obtained: B node T1 time-domain signals transmitted to the data X (k), which is equivalent to the complex passband signal s (k) = x (k) exp (2 X pi X j X ftx X k X Ts) wherein, FTX carrier frequency transmitted; PI is π, j is an imaginary unit; K sampling points subscript; Ts of the sampling interval; at the receiving end, i.e. the a node, ignoring noise, complex the baseband signal
Figure CN105323029BC00031
式中,frx为接收的载波频率;f △为频偏,f △ = f tx-frx; ε = Nf ^Ts = N (f tx_frx) Ts为归一化载波频率偏差,N为采样点数; 两个线性调频信号的总长度为L,中间变量 Wherein, frx of the received carrier frequency; f △ is the frequency offset, f △ = f tx-frx; ε = Nf ^ Ts = N (f tx_frx) Ts is the normalized carrier frequency deviation, N is the number of sampling points; two the total length of the chirp signal is L, the intermediate variables
Figure CN105323029BC00032
其中,D为截取的单个信号为长度;f (·)为r (·)转置; 得到归一化载波频率偏差的估计值为 Wherein, D is the length of a single signal is taken; f (·) of r (·) transposition; obtained normalized carrier frequency offset estimate value
Figure CN105323029BC00033
其中,ZR为R的相位; 根据归一化载波频率偏差ε =Nf ATs = N (ftx_frx) Ts求得h; 依据多普勒原理,估算出同步周期内两个通信节点间的相对速度v; Wherein, ZR phases R; The normalized carrier frequency offset ε = Nf ATs = N (ftx_frx) Ts obtained H; based Doppler principle, the estimated relative velocity v between the two communication nodes synchronization period;
Figure CN105323029BC00034
4. 根据权利要求3所述的基于声链路测距、测速的水声通信动态时钟同步方法,其特征在于:所述步骤(2.3)的归一化载波频率偏差估计值ε的估计范围 4. The method for clock synchronization dynamic acoustic underwater communication link distance, based on speed, wherein according to claim 3: said step (2.3) the normalized carrier frequency offset estimation range of the estimation value ε
Figure CN105323029BC00035
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