CN101494522B - Method for eliminating wireless signal interference based on network encode - Google Patents

Method for eliminating wireless signal interference based on network encode Download PDF

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CN101494522B
CN101494522B CN 200810247342 CN200810247342A CN101494522B CN 101494522 B CN101494522 B CN 101494522B CN 200810247342 CN200810247342 CN 200810247342 CN 200810247342 A CN200810247342 A CN 200810247342A CN 101494522 B CN101494522 B CN 101494522B
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signal
interference
delay
χ
mixed
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CN101494522A (en )
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张婧垚
樊平毅
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清华大学
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Abstract

The present invention relates to a method for eliminating wireless signal interference based on network coding and a system thereof. The method comprises the following steps: a frame of mixed signal s comprising an interference signal x and a useful signal y is received; under the condition that x is known, after different time delay is carried out, relevant operation is carried out to the known local interference signal x' and s respectively; the time delay D with the operation result of the relevant operation of largest is determined as time delay of the x relative to the y; after the time delay D is carried out to the x', the result of the relevant operation of x' and s is divided by frame size so as to determine the signal amplitude Hx' of x relative to y; and the interference signal is eliminated from the mixed signal according to D and Hx'. The invention allows that two transmitting nodes in the receiving range of a node are transmitted simultaneously, thus improving the utilization ratio of the channel without needing the transmitting end to carry out strict control to synchronization and power and being applicable to a distributed type asynchronous transmission network.

Description

一种基于网络编码的无线信号干扰消除方法 Method for eliminating radio interference signal based on network coding

技术领域 FIELD

[0001] 本发明涉及无线通信领域,具体涉及可应用到无线局域网、无线移动网络、无线自组织网络和无线信号处理中的基于网络编码的无线信号干扰消除方法。 [0001] The present invention relates to wireless communication field, and particularly relates to the wireless local area network, a wireless network based on the interference signal coding wireless mobile networks, wireless ad-hoc network and a wireless signal processing method of elimination.

背景技术 Background technique

[0002] 网络编码(Network Coding)指出允许路由器对不同的信息流进行编码组合可以达到容量上界。 [0002] Network coding (Network Coding) noted that allows the router to different stream combinations may achieve the capacity to encode upper bound. 网络编码和路由器有机的融为一体,彻底改变了交换/路由器只能对信息进行存储转发的传统多播模式,建立起一种全新的网络体系结构及信息编码和传输模式。 Network coding and the organic integration of the router, completely changed the switch / router can only store and forward the information of the traditional multicast mode, to establish a new network architecture and information coding and transmission mode. 网络编码代表了一种协同工作的理念,这使得它的应用不仅仅局限于改进多播增加网络容量;与其它技术相结合已经应用于网络管理、纠错、信息安全、P2P对等网络通信、路由和交换等数十个领域。 The concept of network coding representative of one kind of work, which makes its application is not limited to improved multicast increase network capacity; combined with other techniques have been used in network management, error correction, the communication network information security, P2P peer, routing and switching, dozens of fields.

[0003] 国际上许多著名的科研机构如贝尔实验室和麻省理工大学都参与了这一领域的研究。 [0003] Many internationally renowned research institutions such as Bell Labs and MIT are involved in research in this field. 不仅如此,包括微软、惠普、英特尔在内的众多高科技企业也在这一技术的应用方面作了大量的投入,其中英特尔正在研究将网络编码引入其WiMax产品中,以提高吞吐量,增加产品的竞争力。 Not only that, including Microsoft, Hewlett-Packard, Intel, including many high-tech companies are also applications of this technology made a lot of investment, of which Intel is studying the introduction of its WiMax network coding products in order to improve throughput, increase product competitiveness. 然而,无线信道的广播性以及由此带来的信号干扰大大制约了网络编码优势的发挥,目前并没有在无线网络中应用网络编码来解决信号干扰的具体的实用技术手段。 However, the radio channel broadcast signal interference as well as the resulting advantages of network coding has greatly restricted the play, specific technical means there is no practical application of network coding in wireless networks to address signal interference.

[0004] 国内学术界和业界对网络编码也越来越重视。 [0004] Domestic academia and industry to network coding more and more attention. 在2008年度的国家自然科学基金项目规划中,网络编码被列为重点支持项目。 National Natural Science Foundation project planning for 2008, the network coding is listed as key support for the project. 但目前研究还主要集中在理论分析阶段,并未涉及到网络编码在工程上,特别是在无线网络中的具体实现问题。 But the study also focused on the theoretical analysis phase, did not involve the network coding in engineering, especially in the wireless network specific implementation issues. 无线网络中的信号干扰已成为影响其网络性能的一大因素,因此,迫切需要一种基于网络编码的无线信号干扰消除方法来提高无线网络中容量和效率。 Signal interference in a wireless network has become a major factor affecting the performance of the network, therefore, an urgent need for a network coding method based on radio signal interference cancellation in a wireless network to improve capacity and efficiency.

发明内容 SUMMARY

[0005] 本发明的目的是提供一种基于网络编码的无线信号干扰消除方法,目的是将有用的信号从混叠在一起的同时同频信号中有效的分离开来,以增加网络的传输容量。 [0005] The object of the present invention is to provide a method for eliminating signal interference radio network coding based on the purpose of a useful signal with the pilot signal from the valid aliased together while separated, in order to increase the transmission capacity of the network . 该方法适用于多种不同的调制方式,并且不需要各终端间进行严格的时间同步或功率控制,因此具有较高的灵活性和实用性。 This method is applicable to many different modulation scheme, and does not require strict time synchronization or power control of each terminal, thus having a higher flexibility and practicality.

[0006] 为实现上述目的,本发明采用如下技术方案: [0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] —种基于网络编码的无线信号干扰消除方法,包括: [0007] - based on the kind of radio signal interference cancellation network coding method, comprising:

[0008] 接收一帧包含干扰信号χ和有用信号y的混合信号s ; [0008] receiving a mixed signal comprising an interference signal s χ and useful signal y;

[0009] 在干扰信号χ已知的情况下,将本地已知的干扰信号χ'进行不同延时后分别与s 作相关运算; After [0009] [chi] in the presence of interference signals is known, the known local interference signal χ 's with different delays for each correlation calculation;

[0010] 将使相关运算结果最大的延时D确定为X相对于1的延时; [0010] will delay the maximum correlation operation result D is determined with respect to X 1 delayed;

[0011] 将χ'进行延时D后与S作相关运算的结果除以帧长,确定χ相对于y的信号幅值Hx';[0012] 根据所确定的干扰信号χ相对于有用信号y的延时D和信号幅值Hx',利用公式sk = Hyyk+Hxx' k_D。 [0011] The χ 'and S as a result of the correlation operation after delay D by the frame length, [chi] is determined relative to the signal levels y Hx'; [0012] [chi] phase according to the determined interference signal useful for signal y signal amplitude and delay D Hx ', using the formula sk = Hyyk + Hxx' k_D. . sy +nk从混合信号中消去干扰信号;其中,%为经过滤波和解调后,混合信号s在每个采样时刻的离散信号;HX为干扰信号χ的信道增益;yk为有用信号的离散信号表达方式,¾'为本地已知的干扰信号的离散信号表达方式,、为yk的模拟信号形式与χ' k_D的模拟信号形式载波间的相位差;信号幅值H' x = HxC0s γ ;延时乃=£)。 sy + nk cancel interference signals from the mixed signal; wherein, after filtering and demodulation% After mixing signal discrete signal s at each sampling instant; HX is the channel gain of the interference signal χ; YK useful signal discrete signal expression, ¾ 'discrete signal known to the local expression of the interference signal into an analog signal form ,, and χ yk' of a phase difference between a carrier in the form of an analog signal k_D; signal amplitude H 'x = HxC0s γ; Yan when is the = £).

[0013] 优选地,在进行相关运算前还包括步骤: [0013] Preferably, before performing the correlation operation further comprises the step of:

[0014] 对混合信号s进行解调得到离散采样信号% ; [0014] s is demodulated mixed signal to obtain discrete signal samples%;

[0015] 将本地已知的干扰信号X'映射为离散采样信号X' k; [0015] interference signals of known local X 'is mapped to a discrete sampled signal X' K;

[0016] 相关运算步骤中,将χ' k进行不同延时d后分别与、作相关运算: After [0016] The correlation operation step, the χ 'k and d are different delays, correlation calculation made:

[0017] [0017]

[0018] 其中,L为帧长,其中k为正整数,表示采样时刻点的序号。 [0018] where, L is the frame length, where k is a positive integer representing the number of sampling time points.

[0019] 优选地,若信道间存在延时扩展,还包括根据信道的最大延时扩展m,求出干扰信号在不同采样时刻造成的串扰幅度的步骤: [0019] Preferably, if the inter-channel delay spread is present, further comprising m The maximum delay spreading of channel, the step of causing the crosstalk amplitude interference signals obtained at different sampling timing:

[0020] [0020]

[0021] 其中,i为正整数,|i|≤m,且i乒0 ; [0021] where, i is a positive integer, | i | ≤m, ping and i 0;

[0022] 在消除干扰信号步骤中,还包括根据m和#利用公式 [0022] In the step of eliminating interference signals, further comprising using the formula of m and #

消除干扰信号由于延时扩展造成的串扰的子步骤,其中Λ 为从混合采样信号%中消除干扰信号&由于延时扩展造成的串扰后的有用信号。 Substep crosstalk canceling interference signals caused due to the delay spread, wherein Λ is the elimination of an interference signal from the mixed signal samples% & useful signal after crosstalk caused due to the delay spread.

[0023] 优选地,所述延时d的取值范围为-L < d < L。 [0023] Preferably, the delay d is in the range of -L <d <L.

[0024] 优选地,该方法中接收的混合信号采用二进制相位键控调制得到,对混合信号s 采用二进制相位键控解调得到离散采样信号%。 [0024] Preferably, the method of the mixed signal received binary phase shift keying modulation obtained, the mixed signal s binary phase shift keying demodulating signal obtained discrete sample%.

[0025] 优选地,该方法中相同帧采用相同的帧编号,接收s的接收端存储接收s之前设定时间段内收到的所有帧,根据帧编号来判断所述干扰信号X是否已知。 [0025] Preferably, the method of the same frame with the same frame number, frame period setting all received before the receiving terminal stores the received s s received, the frame number is determined according to whether the interference signal known X .

[0026] 优选地,s来自多个节点,各节点首先发送包含帧编号的广播信号,接收端根据帧编号判断得出只有来自一个节点的帧为未接收帧时,向各节点发出允许发送信号。 [0026] Preferably, s from the plurality of nodes, each node comprising a first transmission frame number of the broadcast signal, the receiver only obtained for frames from one node does not receive a frame, to allow each node sends a transmission signal from the frame number determination .

[0027] 本发明还提供了一种基于网络编码的无线信号干扰消除系统,该系统包括: [0027] The present invention further provides a wireless network coding signal interference cancellation system, the system comprising:

[0028] 接收器,接收一帧包含干扰信号χ和有用信号y的混合信号s ; [0028] The receiver that receives a mixed signal comprising an interference signal s χ and useful signal y;

[0029] 干扰信号识别器,用于识别干扰信号χ在本地是否已知; [0029] The interference signal recognizer for identifying interfering signals χ known whether locally;

[0030] 延迟控制器,用于对本地已知的干扰信号χ'进行不同延时; [0030] The delay controller, known locally for the interfering signal χ 'different delays;

[0031] 相关运算器,用于将延迟控制器的输出分别与s作相关运算; [0031] The correlation operator, the delay controller for outputting the correlation operations respectively for s;

[0032] 判断比较器,用于比较相关运算结果判断其是否最大; [0032] determining comparator for comparing the result of correlation calculation is determined whether the maximum;

[0033] 延时确定器,用于将使相关运算结果最大的延时D确定为χ相对于y的延时; [0033] The delay time determination unit configured to enable correlation-operation result D is determined as the maximum delay χ y with respect to the delay;

[0034] 幅值计算器,用于将X'进行延时£)后与s作相关运算的结果除以帧长,计算出X 相对于y的信号幅值Hx'; [0034] The magnitude calculator for converting X 's as a result of the correlation operation after delay £) divided by the frame length, X is calculated with respect to the amplitude of the signal y Hx';

[0035] 干扰消减器,用于根据所确定的干扰信号χ相对于有用信号y的延时力和信号幅值Hx',利用公式% = HyydHxx' k_D。 [0035] The interference reducer, according to the determined interference signal χ with respect to the useful signal y and a delayed signal amplitude force Hx ', using the formula% = HyydHxx' k_D. . sY+nk从混合信号中消去干扰信号;其中^为经过滤波和解调后,混合信号s在每个采样时刻的离散信号;HX为干扰信号χ的信道增益;yk为有用信号的离散信号表达方式,为本地已知的干扰信号的离散信号表达方式,Y为yk的模拟信号形式与χ' k_D的模拟信号形式载波间的相位差;信号幅值H' x = HxC0s γ;延时D = D0 sY + nk cancel interference signals from the mixed signal; where ^ is the filtered and demodulated after mixing signal discrete signal s at each sampling instant; HX is the channel gain of the interference signal χ; discrete signal yk expressed useful signal mode, the local expression of the interference signal known discrete signals, Y is an analog signal form and χ yk 'of a phase difference between a carrier in the form of an analog signal k_D; signal amplitude H' x = HxC0s γ; D = delay D0

[0036] 优选地,所述接收器包括: [0036] Preferably, the receiver comprising:

[0037] 低通滤波器,用于对接收的混合信号s的初始模拟信号进行滤波; [0037] The low-pass filter for initial analog signal s received mixed signal filtering;

[0038] 解调器,用于对经滤波的混合信号解调得到离散采样信号%。 [0038] The demodulator for the discrete sampling signal demodulated filtered mixed signal%.

[0039] 优选地,若信道间存在延时扩展,最大延时扩展为m时,该系统包括串扰幅度计算器,用于根据信道的最大延时扩展m,求出干扰信号在不同采样时刻造成的串扰幅度应,.: When [0039] Preferably, if the inter-channel delay spread is present, m is the maximum delay spread, the system includes crosstalk magnitude calculator for extended m the maximum delay of the channel, causing interference signal obtained at different sampling time crosstalk magnitude should,:

λ 2L-1 λ λ 2L-1 λ

[0040] [0040]

[0041] 其中,i为正整数,|i| <m,且i乒0; [0041] where, i is a positive integer, | i | <m, and i ping 0;

m m

[0042] 所述干扰消减器根据m和仓众利用公式 [0042] According to the interference reducer using the formula m and all the bins

—m ·—.... -m · -....

<min{L+D,L})消除干扰信号由于延时扩展造成的串扰,其中Λ为从混合采样信号%中消除干扰信号&由于延时扩展造成的串扰后的有用信号。 <Min {L + D, L}) to eliminate the crosstalk due to the delay spread caused by the interference signal, wherein Λ is the canceling interference signals from the mixed signal samples% & useful signal after crosstalk caused due to the delay spread.

[0043] 优选地,所述干扰信号识别器包括: [0043] Preferably, said interference signal identifier comprises:

[0044] 存储器,用于存储在接收s之前设定时间段内收到的所有帧; [0044] memory, for storing a set of all frames received prior to receiving period S;

[0045] 广播信号接收器,用于在接收混合信号s之前首先接收来自各节点的广播信号, 所述广播信号包含将要发送的帧的帧编号; [0045] The broadcast signal receiver, for receiving broadcast signals from each first node before receiving the mixed signal s, the broadcast signal comprising a frame number of the frame to be transmitted;

[0046] 帧编号比较器,用于根据广播信号中的帧编号与存储器内帧的帧编号的比较结果,来识别干扰信号X在本地是否已知。 [0046] The frame number comparator for comparing a broadcast signal with the comparison result of the frame number of the frame number of the frame memory to identify whether an interference signal X is known locally.

[0047] 本发明利用了接收端对干扰信号的预知性,从混杂的波形中“抓住”干扰信号并将其“剥离”出来。 [0047] The present invention takes advantage of predictability of the interference signal receiving end, from the mixed waveform "grab" and the interference signals "peeling" them. 这样做的好处是允许一个节点接收范围内的两个或多个发送节点同时发送,从而提高了信道的利用率。 The advantage of this is that it allows two or more nodes within receiving range of a transmitting node transmitting simultaneously, thereby improving channel utilization. 而且由于能有效的估计出干扰信号相对于有用信号的延迟和幅值,不需要发送端进行严格的同步和功率控制,甚至不需要对载波相位进行同步,非常适合分布式的异步传输网络。 And because the effective interference signal with respect to the estimated delay and amplitude of the useful signal, the transmitting side does not need strict synchronization and power control, not even require carrier phase synchronization, asynchronous transfer is suitable for distributed networks.

[0048] 附图说明 [0048] BRIEF DESCRIPTION OF DRAWINGS

[0049] 图1为无线网络中数据接收示意图; [0049] FIG. 1 is a schematic diagram of a wireless network, receiving data;

[0050] 图2为本发明基于网络编码的无线信号干扰消除方法流程图; [0050] FIG second radio network coding signal interference elimination flowchart of a method of the present invention;

[0051] 图3为本发明实施例中基于网络编码的无线信号干扰消除方法流程图; [0051] Figure 3 a wireless network based on the interference signal coding flowchart of a method embodiment of the present invention eliminate the embodiment;

[0052] 图4为本发明实施例中网络编码的无线信号干扰消除系统的结构框图。 [0052] FIG. 4 embodiment radio signal interference network coding system block diagram of the embodiment of the present invention to eliminate.

[0053] 具体实施方式 [0053] DETAILED DESCRIPTION

[0054] 本发明提出的基于网络编码的无线信号干扰消除方法及系统,结合附图和实施例说明如下。 [0054] The present invention is proposed based on network coding method and a wireless signal interference elimination system, in conjunction with the accompanying drawings and the embodiments described below.

[0055] 本发明无线信号干扰消除方法及系统的适用对象介绍如下:适用于无线网络,网络的拓扑结构不限;网络中的各终端处于半双工的工作状态,即每个终端在任一时刻可以接收或发送信息,但收和发不能同时进行;各终端用同一频段发送信息(因为如果不是同频,则不会出现信号干扰);无线信道为高斯白噪声(AWGN)信道或者块衰落(BlockFading)信道,即在一帧数据的传输期间,信道的增益基本保持不变或变化很小。 Suitable [0055] The present invention is a wireless signal interference cancellation method and system are described below: For a wireless network, the network topology is not limited; network each terminal is in a half-duplex operation state, i.e., each terminal at any one time You may receive or transmit information, but can not receive and transmit at the same time; each terminal transmits information using the same frequency band (if not the same as the frequency, signal interference does not occur); radio channel is Gaussian white noise (AWGN) channel or block fading ( BlockFading) channel, i.e. during the transmission of a data frame, the gain of the channel remains substantially constant or changes very little.

[0056] 无线网络中由于功率有限,网络中每个节点都有一个最大的有效传输范围,定义为有效传输半径R。 [0056] Due to the limited power in a wireless network, each node in the network has a maximum transmission range, defined as the effective transmission radius R. 在上述条件的无线网络中,往往有多个节点在同时发送或接收信息帧。 In the above-described conditions in a wireless network, often have multiple nodes simultaneously transmit or receive information frames. 如果一个接收节点处于两个发送节点的有效传输范围之内,两个发送节点在同一时隙发出的信号就可能混叠在一起,导致接收失败。 If received within effective transmission range of a node is transmitting two nodes, the nodes transmit two signals in the same time slot may aliasing issued together, leading to reception failure. 为便于理解,给出下面一个简单的网络拓扑结构在传统条件下的时隙分配及采用本发明消除干扰情况下的时隙分配。 For ease of understanding, given a simple network topology and the following time slot assignment according to the present invention eliminates interference in the time slot assignment under conventional conditions.

[0057] 如图1所示,若在同一时隙内,发送节点S1向接收节点R1发送信息X,发送节点& 向接收节点&发送信息1。 [0057] 1, in the same time slot when transmitting node S1 transmits information to the receiving node X R1, & transmits information transmitting node & 1 to the receiving node. 由于&同时处于S1和&的传输范围之内,将χ视为干扰信号, 而将y视为有用信号,因此,干扰信号X会在&处对有用信号y造成干扰,导致&无法正确接收到ι,因此在传统的网络中S1和&不能同时发送。 Since the S1 and & & simultaneously in the transmission range, the χ as interference signals, and y is treated as the useful signal, and therefore, interference signal X will be useful signal y & cause interference, the cause can not correctly received & ι, S1, and thus it can not be transmitted simultaneously in conventional & networks. 但是,如果&以前曾经收到过χ,就可以利用对χ的已知性,有效的消除χ的信号对y造成的干扰,这样即使S1和&同时发送, 也能保证&正确的收到y。 However, if χ & previously received, you can use the known properties of χ, χ effectively eliminate the interference caused by signals on y, so that even if S1 simultaneously transmit and &, & can be guaranteed the right to receive y. 这就是网络编码的原理。 This is the principle of network coding.

[0058] 值得注意的是,上述假设的&以前曾经收到过χ,又同时接收包含χ和y的混合信号的情形在多跳传输中是经常存在的。 [0058] It is worth noting that the case had previously received & χ, and simultaneously receives a mixed signal containing the [chi] and y are assumed in the multi-hop transmission is often present. 如图1中,如果&要通过S-R2-S1-R1路径向R1依次发送信息χ和y,在某个时隙,S1向队传递χ时,S2也同时向&传递y,R2先前已经收到过χ 了(因为是由&向S1RSxh这时利用本发明提出的基于网络编码的干扰消除方法,S2 向R2发送y,与S1向R1发送χ就可以同时进行了,而不必分两个时隙进行,从而节省了时间,提高了信道的利用率。 As shown in FIG. 1, if you want to send via & S-R2-S1-R1 path sequence information in the R1 χ and y, at a certain time slot, the team Sl transmitted χ, S2 is transmitted simultaneously to the & y, R2 have been previously χ received (because this time is & S1RSxh to eliminate the use of network-based interference coding method proposed by the present invention, S2 transmits y to R2, R1 and S1 sent to the χ can be carried out simultaneously, rather than two time slots, thus saving time, improve the utilization of the channel.

[0059] 下面给出本发明基于网络编码的无线信号干扰消除方法及系统的优选实施方式。 [0059] The present invention is given below wireless network coding based on the interference signal elimination preferred embodiment of the method and system.

[0060] 实施例 [0060] Example

[0061] 无线网络中若接收端事先已知道将要接收的包含干扰信号χ和有用信号y的混合信号s中的干扰信号时,并不能用接收后的混合信号直接与干扰信号X相减获取有用信号, 这是因为干扰信号经传输一方面可能与有用信号不同步,即存在延时,另一方面由于信道增益不同,信号传递过来幅值也会发生变化,因而,如何估计传递过来后的干扰信号X相对于有用信号y的延时和信号幅值,是网络编码的目的。 [0061] The wireless network if the receiving end are known in advance when an interference signal the mixed signal s contains interference signals χ and useful signal y to be received, does not use the mixed signal received directly interfering signal X is subtracted to obtain useful signal, because the interference signal via a transmission aspect may not synchronize with the desired signal, i.e. there is no delay, on the other hand due to the different channel gain, signal amplitude will change over the transfer, therefore, how to estimate the interference over the transmission X with respect to the signal delay and signal amplitude of the useful signal y, is the object of the network coding. 为便于区别,后面用符号χ'表示本地已知的干扰信号,以区别实际传输过来的干扰信号X。 For ease of distinction, behind 'represents known local interference signal the interference signal difference transmitted over the actual symbol χ X.

[0062] 如图2所示为本发明方法流程图,该方法包括:s201,接收一帧包含干扰信号χ和有用信号y的混合信号s ;s202,在干扰信号χ已知的情况下,将本地已知的干扰信号χ'进行不同延时后分别与s作相关运算;s203,将使相关运算结果最大的延时0确定为χ相对于y的延时;s204,将χ'进行延时D后与s作相关运算的结果除以帧长,确定χ相对于y 的信号幅值Hx' ;s205,根据所确定的干扰信号χ相对于有用信号y的延时D和信号幅值Hx',从混合信号中消去干扰信号。 Method [0062] The flowchart shown in FIG. 2 of the present invention, the method comprising: s201, receiving a mixed signal comprising an interference signal s χ and useful signal y; S202, in the case of known interference signal χ, the known local interference signals χ 'after different delay time respectively as a relative s operation; s203, will delay the maximum correlation calculation result is determined as 0 [chi] y with respect to the delay; s204, the χ' to delay s for the correlation operation result after dividing the frame length D, χ is determined with respect to the signal amplitude Hx y '; s205, in accordance with the determined interference signal with respect to χ delay D and the signal amplitude of the useful signal y Hx' , from the mixed signal cancel interference signals.

[0063] 接收端接收的是混合信号s的初始模拟信号形式的信号,由于信号的波形与调制方式有关,对于不同的调制方式,步骤202中相关运算的函数表达式有所不同,但原理是一样的。 [0063] A receiving end receives the initial analog signal form the mixed signal s signal, since the waveforms related to the modulation signal for different modulation scheme, in step 202 the correlation calculation function expression is different, but the principle is the same. 不失一般性地,本实施例以二进制相位键控调制BPSK (Binary Phase Shift Keying) 为例。 Without loss of generality, the present embodiments are binary phase shift keying modulation BPSK (Binary Phase Shift Keying) as an example. 为了清楚地说明方法的具体步骤,引入如下符号: To clearly illustrate specific steps of the method, the following notation is introduced:

[0064] L :每帧数据所含有的符号数,即表示帧长; [0064] L: number of symbols contained in each frame of data, i.e., indicates the frame length;

[0065] χ = {Xl,X2, ... , xL}:干扰信号的离散信号表达方式,也可以用&表示; [0065] χ = {Xl, X2, ..., xL}: discrete signal expression interfering signals may be represented by &;

[0066] x(t):干扰信号的模拟信号表达方式;[0067] y = {Yl, J2,..., yL}:有用信号的离散信号表达方式,也可用yk表示; [0066] x (t): analog expression interference signal; [0067] y = {Yl, J2, ..., yL}: discrete signal expression of the desired signal can also be represented by yk;

[0068] y(t):有用信号的模拟信号表达方式; [0068] y (t): a useful expression analog signal;

[0069] n, n(t),nk :高斯白噪声(η为高斯白噪声的一般表示,n(t)为η的模拟信号表达方式,nk为η的离散信号表达方式; [0069] n, n (t), nk: white Gaussian noise (Gaussian white noise [eta] is a general representation, n (t) [eta] is the expression of an analog signal, nk discrete signal is expressed as a [eta];

[0070] Hx, Hy :分别干扰信号χ和有用信号y对应的信道增益; [0070] Hx, Hy: χ each interfering signal and the desired signal y corresponding channel gain;

[0071] D :干扰信号χ相对于有用信号y的延迟; [0071] D: χ with respect to the interfering signal delay of the useful signal y;

[0072] 上面各符号及后面叙述中,k为正整数,表示采样时刻点的序号,t表示时间信号。 [0072] The above description and following each symbol, k is a positive integer representing the number of sampling time points, t represents time signal.

[0073] 对于在无线网络中发送端和接收端采用BPSK进行调制和解调的情况,接收端同时收到的包含干扰信号χ和有用信号y的混合信号s的初始模拟信号r (t)可以表示为: [0073] In the case of the transmitting end and receiving end for BPSK modulation and demodulation in a wireless network, a receiving end while the initial signal r mixed analog signal comprising an interference signal s χ and y is the received useful signal (t) may Expressed as:

[0074] r (t) = Hyy (t) cos ω t+Hxx' (t~D) cos (ω t+γ )+η (t) (1) [0074] r (t) = Hyy (t) cos ω t + Hxx '(t ~ D) cos (ω t + γ) + η (t) (1)

[0075] 其中,ω为BPSK调制的角频率,、是两个信号y(t)和χ' (t_D)载波间的相位差。 [0075] where, ω is the angular frequency,, BPSK modulation is two signals y (t) and χ '(t_D) a phase difference between the carriers.

[0076] 经过滤波和解调后,每个采样时刻的离散信号、可以表示为: [0076] After filtering and demodulation, each discrete signal sampling instant can be expressed as:

[0077] sk = Hyyk+Hxx' k_Dcos y +nk (2) [0077] sk = Hyyk + Hxx 'k_Dcos y + nk (2)

[0078] 从式⑵可知,在已知干扰信号χ'的情况下,只要求出H' x = HxCos γ和延迟D, 就可以将干扰信号X所带来的干扰从接收的解调后的混合信号%中“减去”,恢复出有用信号y。 [0078] apparent from the equation ⑵, in the known interference signals χ 'of the case, as long as the determined H' x = HxCos γ and delay D, can be brought interfering signal X from the received demodulated mixed signal% "minus" to recover the useful signal y. 由于接收终端已知的干扰信号为X',本实施例中首先将干扰信号X'映射与%具有相同离散形式,即χ' =Ix1' , χ2' , ..., xL' },然后与混合采样信号%作相关运算: Since the received interfering signal is known to the terminal X ', in this embodiment the first interfering signal X' has the same mapping% discrete form, i.e., χ '= Ix1', χ2 ', ..., xL'}, and then % mixed sampled signal for correlation calculation:

[0079] [0079]

[0080] 其中,d表示延时,取值范围为_L<d<L,也就是说干扰信号χ'相对于y的最大延迟|DI <L,因为如果|DI ^ L,x'和y在时间上就不再有交叠部分了,χ'对y也就不构成干扰了。 [0080] wherein, d represents delay, ranging _L <d <L, that is to say the interference signals χ 'relative to the maximum delay y | DI <L, because if | DI ^ L, x' and y in time no longer has the overlapping portion, χ 'of the interference does not become a y. 由于-L<d<L,设y= {71,72,...,7],如果以71所在时刻为0时亥1],由于s是y和延迟后的χ'的叠加,s的起止时刻最多分别为-L和2L-1。 Since -L <d <L, set y = {71,72, ..., 7], where if the time is 0, 71 Hai 1], since the s and y is the delay χ 'superimposed, the s up to the beginning and ending time, respectively, and -L 2L-1. 为了简单起见,本实施例中相关运算的取值区间设为[_L,2L_1]。 For simplicity, the embodiment set value interval calculation related to the present embodiment [_L, 2L_1].

[0081] 在二进制相位键控调制BPSK调制中,,71;曰{-1,1},并且其概率? [0081] In the binary phase shift keying modulation BPSK modulation ,, 71; said {-1,1}, and the probability? 0^ = 1) =P(Xk' =-1) =P(yk=l) =P(yk = -l) = 0.5,其中P表示取概率。 0 ^ = 1) = P (Xk '= -1) = P (yk = l) = P (yk = -l) = 0.5, where P represents the probability of taking. 根据信源编码的规律,信息经过信源编码编码后,一帧数据中不同时刻的符号间是不相关的。 According to the rule source coding, the information source coding after coding, an inter-symbol data at different time is irrelevant. 所以有: So have:

[0082] [0082]

[0083] [0083]

[0084] 其中,E表示取数学期望。 [0084] wherein, E represents the mathematical expectation taken.

[0085] 在上面的理论基础上,根据大数定律,随着L取值的增大, [0085] The theoretical basis of the above, according to the law of large numbers, as the L value is increased,

[0086] [0086]

[0087] 概率0的概率就越大,当L为无穷大时,(1')和0')趋于0的概率为1。 [0087] 0, the greater the probability that when L is infinite, (1 ') and 0') tends to 0 the probability is 1. [0088] 而对于民',则有:随着L取值的增大, [0088] For China ', then: L increases as the value of

[0089] 若d = D,//xi x'ft_rf /Z趋于Hx'的概率越大,当L为无穷大时,以概率1趋 [0089] If d = D, // greater probability xi x'ft_rf / Z tends Hx 'when L is infinite, with probability 1 chemotaxis

[0090] 若d ^ Ό,ΗΧ' Μ趋于0的概率越大,当L为无穷大时,以概率1趋于 [0090] If d ^ Ό, ΗΧ 'Μ greater probability tends to 0 when L is infinite, with probability 1 tends

[0091] 因此,随着L的增大,R(s,x',D)是所有的R(s,x',d) (_L < d < L)中最大值的概率增大。 [0091] Thus, as L increases, R (s, x ', D) are all of the R (s, x' probability, d) (_L <d <L) of the maximum value is increased. 如果L足够大,R(s,x',D)是所有的R(s,x',d)(-L<d<L)中最大值的概率为1。 If L is large enough, R (s, x ', D) are all of the R (s, x', d) - the probability (L <d <L) is a maximum value. 实验证明,实际中帧长的取值使R(s,χ',D)是所有的R(s,χ',d)(-L<d<L) 中最大值的概率很大。 Experiments show that the actual value of the frame length R (s, χ ', D) are all of the R (s, χ', d) - the probability of large (L <d <L) of the maximum value. 基于该理论推导结果,只要对每个4<(1<1^范围内的d求|R(s, x',d) I,并取出其中最大的一个,就能以概率1准确估计出信号幅值Hx'和延时D,其中估计得到的延时为^,从而消除χ所带来的干扰。 Based on the theoretical analysis result, as long as each of the 4 <(1 <1 ^ d seek range | R (s, x ', d) I, and wherein a maximum extraction, in order to be able to accurately estimate the probability of a signal magnitude of Hx 'and delay D, where ^ is the estimated time delay, thereby eliminating interference caused by χ.

[0092] 以上的分析没有考虑延时扩展。 [0092] The above analysis does not consider the delay spread. 对于频率选择性衰落的信道,会由于延时扩展而带来符号间串扰。 For frequency-selective fading channels, due to inter-symbol delay spread brought crosstalk. 那么根据式0),x' k_D不仅会对yk造成干扰,还会干扰到yk前后几个符号。 So interfere with the equation 0), x 'k_D not only have yk, but also interfere with several symbols before and after yk. 为了彻底消除干扰信号χ引起的干扰,本实施例中采用下面的方法,首先根据信道的类型确定最大延时扩展m,即确定χ' k_D除会对yk造成干扰,对前后几个采样时刻的有用信号还造成干扰,然后分别算出χ' k_D在不同采样时刻造成的串扰的幅度: In order to eliminate the interference caused by the interfering signal [chi], the following method embodiment according to the present embodiment, the maximum delay spread is first determined according to the type of channel m, i.e. determined χ 'k_D will cause interference with other YK, several sampling time before and after the also interfere with the useful signal, and then respectively calculates χ 'k_D causes crosstalk levels at different sampling timing:

[0094] 其中D是根据前述方法得到的D的估计值,即 [0094] wherein D is an estimated value obtained according to Method D, i.e.,

[0096] 然后从混合采样信号%中“减去” X所有的符号间串扰,得: [0096] Then the sample from the mixed signal in% "minus the" crosstalk among all the symbols X, to give:

[0098] 其中m是信道的最大延迟扩展,根据信道状况来选择。 [0098] where m is the maximum delay spread of the channel, selected according to channel conditions. 其中i为正整数,I i I ^ m, 当i Φ 0,表示的符号间串扰,当i = 0表示的是对应采样时刻的干扰,若信道间不存在延时扩展,则i =IIi = O0 Wherein i is a positive integer, I i I ^ m, when i Φ 0, inter-symbol represents the crosstalk when i = 0 indicates that the corresponding sampling timing of interference, if the delay spread does not exist between the channels, i = IIi = O0

[0099] 综上,可以得出基于网络编码的无线信号干扰消除方法,见图3。 The [0099] Fully, you can obtain a wireless signal interference cancellation method based on network coding, see Fig. 该流程图以BPSK 调制为例,对于其他的调制方式,只要改变相干函数的表达式就可以了。 The flowchart is an example BPSK modulation, other modulation scheme, as long as the coherence function of the expression change it. 该方法包括步骤s301,初始化各量,即d = -L+1, Hd = 0, H' i = 0,yk = sk(k = 0 〜L_l),表示一帧数据; 步骤s302,根据式(3)进行相关运算R(s,x',d),并计算Hd = R(s,x',d)/L ;步骤s303, 判断I < |Hd|是否成立,若成立,执行步骤s304,否则,执行步骤s305 ;步骤s304,执行H' 1 =礼,力=^,执行步骤8305 ;步骤s305,d = d+Ι ;步骤s306,判断d彡L是否成立, 若成立,执行步骤s307,否则返回执行步骤302 ;s307,根据式(¾计算敌;步骤s308,根据式(6)将干扰信号χ消除,结束。仿真结果表明,当L = 2000时,正确估计出D的概率接近95%。因此,对于一般长度的数据包,都可以准确地估计出于扰信息χ相对于有用信息y的延迟D及信号幅值Hx',从而有效地消除干扰。 The method comprises the step S301, the amount of each of the initialization, i.e., d = -L + 1, Hd = 0, H 'i = 0, yk = sk (k = 0 ~L_l), represents a transactions; step S302, according to the formula ( 3) the correlation operation R (s, x ', d), and calculates Hd = R (s, x', d) / L; step S303, determination I <| Hd | is satisfied, if true, execute step S304, otherwise, go to step S305; step S304, execution H '1 = Li, power = ^, step 8305; step s305, d = d + Ι; step S306, determination d San L is satisfied, if true, execute step S307, otherwise, returning to step 302; s307, according to formula (¾ calculated enemy; step S308, in accordance with formula (6) the interference signal χ eliminate, end of the simulation results show that when L = 2000, the correctly estimated probability that D is close to 95% Thus, for a normal length packets can be accurately estimated for scrambling information χ with respect to delay D and the signal amplitude of the useful information y Hx ', effectively eliminating the interference.

[0100] 下面给出采用了本发明的干扰信号消除方法后,本实施例中的无线网络的调度和时隙分配问题。 After [0100] The following presents an interference signal using the method of the present invention to eliminate, for example, a wireless network scheduling and allocation of slot according to the present embodiment. 在典型的单一频率的无线网络如Ad-h0C网络中,传统的MAC层协议例如802. 11系列都规定,一个节点R在接收时,它接收范围内只能有一个节点处于发送状态。 In a typical wireless network, such as a single frequency network Ad-h0C, the conventional MAC layer protocol, such as 802.11 series are predetermined, when a receiving node R, it is within the reception range only one node in the sending state. 但采用了基于网络编码的干扰消除算法以后,有时R的接收范围内也可以有多个节点同时发送,只要它们发送的数据R以前曾经收到过,就不影响R对其有用数据的接收。 However, after using network coding interference cancellation algorithm, and sometimes the reception range R may be a plurality of nodes transmit simultaneously, as long as they transmit the data previously received R, R does not affect its receiving useful data. 为了有效的利用本发明提出的方法,可以采用如下的调度策略。 In order to effectively use the method proposed by the present invention, the following scheduling strategy may be employed. 首先,每个终端都存储在其接收混合信号之前设定时间段内收到的数据,这里时间的长短可以根据接收端的存储空间大小和剩余能量的多少来确定。 First, each terminal stores setting data received prior to the period for receiving a mixed signal, where the length of time may be determined according to the number of storage space and the receiving end of the residual energy. 对每一帧数据,都可以根据其MAC地址、IP包头的序号等作为唯一的编号。 For each frame of data, can be used as a unique number in accordance with its MAC address, IP header number or the like. 当某一节点S准备发送时,根据802. 11协议,通常要先广播一个广播信号RTS (Request to knd)。 When a node is ready to send S The 802.11 protocol, typically a first broadcast signal broadcast RTS (Request to knd). 在这个RTS中加入将要发送的数据帧的编号,那么S周围的节点就可以根据该编号判断以前是否收到过S将要发送的这一帧。 Add this to be transmitted the RTS frame number data, the node S can be around whether the received frame S to be transmitted based on the previously determined number. 假设此时节点T恰好要向节点R发送数据, 并且也发出了RTS。 Assuming that node T node just send data to R, and also sent the RTS. 那么接下来R将分析自己收到的所有RTS,如果发现除了T要发送的帧以外,其他邻近节点即将发送的帧自己以前都收到过,就向T发送CTS (Clear toSend),注意这里R只向T就可以了,因为此时R只想接收T发送的数据,其它的节点,只要没收到来自其目的节点NCTS,就可以确定自己是可以发送了;否则就发送NCTS (Not Clear to Send), 告知T当前不可发送。 Then the next R RTS will analyze all of you have received, if it is found in addition to the T frame to be transmitted, a frame to be sent to other neighboring nodes of his past have received, it sends CTS (Clear toSend) to T, note where R T only to it, because the R T want to receive data transmitted from other nodes, as long as it did not receive from the NCTS destination node, it can be determined that they are transmitted; otherwise transmitting NCTS (not Clear to send ), informed T is not currently available to send. 如果有多个节点要向R同时发送R之前未收到过的数据帧,则R随机选择向其中一个节点发送CTS,并向其它节点发送NCTS。 If there are multiple nodes simultaneously transmit not want to R received data frame prior to R, R is selected randomly wherein one node sending the CTS, and transmits NCTS other nodes. 上述CTS和NCTS中包含着相应帧的编号。 CTS and NCTS above contains a number of the corresponding frame.

[0101] 本发明提出的一种基于网络编码的无线信号干扰消除系统,包括:接收器,接收一帧包含干扰信号X和有用信号y的混合信号S ;干扰信号识别器,用于识别干扰信号X在本地是否已知;延迟控制器,用于对本地已知的干扰信号χ'进行不同延时;相关运算器,用于将延时控制器的输出分别与S作相关运算;判断比较器,用于比较相关运算结果判断其是否最大;延时确定器,用于将使相关运算结果最大的延时力确定为χ相对于y的延时;幅值计算器,用于将X'进行延时力后与S作相关运算的结果除以帧长,计算出χ相对于y的信号幅值Hx';干扰消减器,用于根据所确定的干扰信号X相对于有用信号y的延时D和信号幅值Hx',从混合信号中消去干扰信号。 [0101] One proposed invention eliminates signal interference radio network coding based system, comprising: a receiver for receiving a mixed signal comprising an interference signal S X and useful signal y; interference signal recognizer for identifying interfering signals X are known locally; delay controller for the interference signals of known local χ 'of different delay; correlation operator, the controller for the output delay for correlation operations respectively S; Analyzing comparator for comparing the result of correlation calculation is determined whether the maximum; delay determiner for correlation calculation result will force the maximum delay is determined to delay χ with respect to y; amplitude calculator for X 'for correlation calculation result S as force divided by the frame length of the delay is calculated with respect to the signal amplitude χ y of Hx '; interference reducer, for delaying a useful signal y in accordance with the determined interference signal with respect to X D and signal amplitude Hx ', canceling an interference signal from the mixed signal. 接收器具体包括:低通滤波器,用于对接收的混合信号S的初始模拟信号进行滤波;解调器,用于对经滤波的混合信号解调得到离散采样信号%。 The receiver comprises: a low pass filter for the analog signal initially received mixed signal S filtering; a demodulator configured to obtain a discrete sample signal demodulated filtered mixed signal%.

[0102] 若信道间存在延时扩展,最大延时扩展为m时,该系统包括串扰幅度&计算器, When [0102] If the inter-channel delay spread is present, the maximum delay spread is m, the system comprising & crosstalk amplitude calculator,

用于根据信道的最大延时扩展m,求出干扰信号在不同采样时刻造成的串扰幅度点,: λ 2/,-1 λ M for the maximum delay spread of the channel, the amplitude of the crosstalk caused by the interfering signal point obtained at different sampling timing,: λ 2 /, - 1 λ

[0103] Hi = Z skxk-D+i = R(s' X,力-ο [0103] Hi = Z skxk-D + i = R (s' X, force -ο

k=—L k = -L

[0104] 其中,i为正整数,|i|彡m,且i乒0 ; [0104] where, i is a positive integer, | i | San m, and i ping 0;

[0105] 同时,干扰消减器根据m和应,消除干扰信号由于延时扩展造成的串扰。 [0105] Meanwhile, according to the interference reducer and m should eliminate the crosstalk interference caused by the signal delay due to expansion.

[0106] 优选地,干扰信号识别器包括:存储器,用于存储在接收s之前设定时间内收到的所有帧;广播信号接收器,用于在接收混合信号之前首先接收来自各节点的广播信号,所述广播信号包含将要发送的帧的帧编号;帧编号比较器,用于根据广播信号中的帧编号与存储器内的帧编号的比较结果,来识别干扰信号X在本地是否已知。 [0106] Preferably, the interference signal identification device comprising: a memory for storing a set s prior to receiving all frames received within the specified time; broadcast signal receiver for receiving a broadcast from each node prior to receiving the first mixed signal signal, the broadcast signal to be transmitted contains a frame number of a frame; the frame number comparator for comparing a broadcast signal according to a frame number of the comparison result of the frame number in the memory and to identify whether an interference signal X is known locally. [0107] 本实施例中采用了干扰消除方法的接收端结构见图4。 [0107] The present embodiment uses a method of interference cancellation receiver terminal structure shown in Figure 4. 天线接收到的干扰信号χ 与有用信号y的混合信号s (t)的模拟形式信号r(t)通过滤波和采样后得到S。 Mixed signal received by the antenna interference signal s χ useful signal y (t) of the form of an analog signal r (t) obtained by sampling the filtered and S. 将%暂存到存储器中。 % To the temporary memory. 将本地已知的干扰信号χ'的内容映射成与解调成信号具有相同形式的符号得到X' k。 Known local interference signals χ 'content is mapped to the symbols and demodulated into a signal having the same form obtained X' k. 例如,对于BPSK,χ'中的0映射成-1,1映射成1。 For example, for BPSK, χ 'are mapped to -1, 0 is mapped to 1. 将X' k做不同的延迟d 后与%作相关运算R(s,χ',d),经过比较、判断后选出相关绝对值最大者,作为延迟D的估计值。 The X 'k after a different delay d do with correlation operation as% R (s, χ', d), after comparison, the absolute value of the maximum correlation is determined by selecting, as the estimated value of delay D. 为了节省时间,每个R(s,x',d)的结果都作存储。 To save time, each result R (s, x ', d) are for storage. 在此基础上,按照式(5),从存储下来的R(s,χ',d)中挑选出2m+l个作为干扰信号幅度的估计值敌。 On this basis, according to Equation (5), down from the memory R (s, χ ', d) of the 2m + l th selected as an interference signal amplitude estimate enemy. 然后再按照式(6), 将干扰信号的各个延迟分量从混合信号%中减掉,就得到有用信号的估计值Λ。 Then according to equation (6), each delay interference signal component subtracted from the mixed signal%, to obtain the estimate of the useful signal Λ.

[0108] 可以预期随着芯片技术的飞速发展和通信器件的集成度越来越高,在无线设备中应用网络编码技术所需的成本会越来越低,各种基于网络编码的技术的实用化将为无线通信系统带来可观的性能改善。 [0108] It is contemplated that the degree of integration with the rapid development of chip technology and the communication devices become increasingly high, the cost required for the application of network coding will become lower in a wireless device, a variety of network-based coding technique practical of the wireless communication system will bring considerable performance improvements.

[0109] 以上实施方式仅用于说明本发明,而并非对本发明的限制,有关技术领域的普通技术人员,在不脱离本发明的精神和范围的情况下,还可以做出各种变化和变型,因此所有等同的技术方案也属于本发明的范畴,本发明的专利保护范围应由权利要求限定。 [0109] the above embodiments are merely illustrative of the present invention, and are not restrictive of the invention, relating to ordinary skill in the art, without departing from the spirit and scope of the present invention, can make various changes and modifications , all equivalent technical solutions also within the scope of the present invention, the scope of the present invention patent is defined by the appended claims.

Claims (11)

  1. 1. 一种基于网络编码的无线信号干扰消除方法,包括:接收一帧包含干扰信号X和有用信号y的混合信号S ;在干扰信号χ已知的情况下,将本地已知的干扰信号χ'进行不同延时后分别与s作相关运算;将使相关运算结果最大的延时乃确定为χ相对于ι的延时;将X"进行延时力后与S作相关运算的结果除以帧长,确定χ相对于y的信号幅值Hx';根据所确定的干扰信号X相对于有用信号1的延时力和信号幅值Hx',利用公式% = Hyyk+Hxx' k_DcoSY+nk从混合信号中消去干扰信号;其中,%为经过滤波和解调后,混合信号8在每个采样时刻的离散信号;HX为干扰信号χ的信道增益;yk为有用信号的离散信号表达方式,xk'为本地已知的干扰信号的离散信号表达方式,Y为yk的模拟信号形式与χ' k_D 的模拟信号形式载波间的相位差;信号幅值H' x = HxCos γ ;延时β = /)。 A wireless network based on the interference signal elimination method of encoding, comprising: receiving a mixed signal comprising an interference signal S X and useful signal y; in the case of a known interfering signal χ, the known local interference signals χ 'after the s different latency for each correlation calculation; enable correlation calculation result is the maximum delay is determined to delay with respect to χ ι; and the X and s as a result of the correlation operation delay after power "by frame length determining χ with respect to the signal amplitude y Hx '; X in accordance with the determined interference signal with respect to the useful signal and the delayed power signal amplitude 1 Hx', using the formula% = Hyyk + Hxx 'k_DcoSY + nk from cancel interference signals in the mixed signal; wherein percent after filtering and demodulation, mixed signal 8 discrete signal at each sampling instant; HX is the channel gain of the interference signal χ; discrete signal yk for the expression of the useful signal, XK 'discrete signal is known in the local expression of the interference signal, Y is a form of analog signal and yk [chi]' k_D phase difference between the analog signal in the form of a carrier; signal amplitude H 'x = HxCos γ; delay β = / ).
  2. 2.根据权利要求1所述的方法,其特征在于,在进行相关运算前还包括步骤:对混合信号s进行解调得到离散采样信号%;将本地已知的干扰信号χ'映射为离散采样信号χ' k;相关运算步骤中,将χ' k进行不同延时d后分别与%作相关运算: 21-1R(s,x\d)= ^skx\_d其中,L为帧长,其中k为正整数,表示采样时刻点的序号。 2. The method according to claim 1, characterized in that, before performing the correlation operation further comprises the step of: demodulating the mixed signal s obtained discrete sample signal%; known local interference signals χ 'mapped to discrete samples signal [chi]; the 'k correlation operation step, the [chi]' k and d are different delays% as a relative calculation: 21-1R (s, x \ d) = ^ skx \ _d where, L is the frame length, wherein k is a positive integer representing the number of sampling time points.
  3. 3.根据权利要求2所述的方法,其特征在于,若信道间存在延时扩展,还包括根据信道的最大延时扩展m,求出干扰信号在不同采样时刻造成的串扰幅度或的步骤:Λ 2L-1ι» » v ...其中,i为正整数,|i|彡m,且i乒0;m在消除干扰信号步骤中,还包括根据m和&利用公式Λ 二& - Σ台ixk.D+i (max {O,D} ^k<min{L+D,L})消除干扰信号由于延时扩展造成的串扰的子步骤,其中Λ为从混合采样信号%中消除干扰信号&由于延时扩展造成的串扰后的有用信号。 3. The method according to claim 2, wherein, if the inter-channel delay spread is present, further comprising a maximum delay spread of the channel m, crosstalk or interference signal amplitude due to the different sampling moments in the step of obtaining: Λ »» 2L-1ι v ... where, i is a positive integer, | i | San m, and i ping 0; m step in eliminating the interference signal, and further comprising m & Lambda use according to formula 2 & - Σ station ixk.D + i (max {O, D} ^ k <min {L + D, L}) to eliminate interference signals substep crosstalk caused due to the delay spread, wherein Λ is mixed eliminate the interference signal from the sampled signal in% & useful signal after crosstalk due to the delay caused by the expansion.
  4. 4.根据权利要求2所述的方法,其特征在于,所述延时d的取值范围为-L < d < L。 4. The method according to claim 2, wherein said delay d is in the range of -L <d <L.
  5. 5.根据权利要求2所述的方法,其特征在于,该方法中接收的混合信号采用二进制相位键控调制得到,对混合信号s采用二进制相位键控解调得到离散采样信号^。 5. The method according to claim 2, characterized in that the process the mixed signal received binary phase shift keying modulation obtained, the mixed signal s binary phase shift keying demodulating signal obtained discrete sample ^.
  6. 6.根据权利要求1所述的方法,其特征在于,该方法中相同帧采用相同的帧编号,接收s的接收端存储接收s之前设定时间段内收到的所有帧,根据帧编号来判断所述干扰信号χ 是否已知。 6. The method according to claim 1, characterized in that, in the method of the same frame with the same frame number, the receiving terminal stores all frames received prior to receiving the s s received set period, in accordance with frame number Analyzing the interference signal χ is known.
  7. 7.根据权利要求6所述的方法,其特征在于,s来自多个节点,各节点首先发送包含帧编号的广播信号,接收端根据帧编号判断得出只有来自一个节点的帧为未接收帧时,向各节点发出允许发送信号。 7. The method according to claim 6, characterized in that, s from the plurality of nodes, each node comprising a first transmission frame number of the broadcast signal, the receiver only frames derived from a node is not receiving frames from the frame number determination when, allows each node sends a transmission signal.
  8. 8. 一种基于网络编码的无线信号干扰消除系统,包括:接收器,接收一帧包含干扰信号χ和有用信号y的混合信号s ;干扰信号识别器,用于识别干扰信号X在本地是否已知; 延迟控制器,用于对本地已知的干扰信号X'进行不同延时; 相关运算器,用于将延迟控制器的输出分别与S作相关运算; 判断比较器,用于比较相关运算结果判断其是否最大; 延时确定器,用于将使相关运算结果最大的延时乃确定为X相对于1的延时; 幅值计算器,用于将χ'进行延时乃后与S作相关运算的结果除以帧长,计算出X相对于y的信号幅值Hx';干扰消减器,用于根据所确定的干扰信号χ相对于有用信号y的延时力和信号幅值Hx',利用公式% = Hyyk+Hxx' k_DcoSY+nk从混合信号中消去干扰信号;其中,、为经过滤波和解调后,混合信号s在每个采样时刻的离散信号;HX为干扰信号χ的信道 A wireless network coding signal interference cancellation system, comprising: a receiver for receiving a mixed signal comprising an interference signal s χ and useful signal y; interference signal recognizer for identifying interfering signal X has been locally known; delay controller for an interference signal known to the local X 'of different delay; correlation operator, the delay controller for outputting the correlation operation for S, respectively; Analyzing comparator for comparing the correlation calculation determining whether the maximum result; delay determiner for correlation calculation will result delay is the maximum delay of 1 is determined with respect to X; amplitude calculator for χ 'to delay and after is the S the results for the correlation calculation by dividing the frame length is calculated with respect to the X signal amplitude y Hx '; interference reducer, according to the determined interference signal χ force with respect to the useful signal delay and signal amplitude Hx y ', using the formula% = Hyyk + Hxx' k_DcoSY + nk cancel interference signals from the mixed signal; ,, wherein after demodulation and filtering through, mixed signal discrete signal s at each sampling instant; the HX is an interference signal of χ channel 益;yk为有用信号的离散信号表达方式,为本地已知的干扰信号的离散信号表达方式,Y为yk的模拟信号形式与χ' k_D的模拟信号形式载波间的相位差;信号幅值Hx = Hx cosy;延时D =D。 Yi; discrete signal yk for the expression of the useful signal, a signal known to the local expression of discrete interference signal, Y [chi] is a form of analog signal yk and a phase difference between a carrier in the form of an analog signal k_D '; signal amplitude Hx = Hx cosy; delay D = D.
  9. 9.根据权利要求8所述的系统,其特征在于,所述接收器包括: 低通滤波器,用于对接收的混合信号s的初始模拟信号进行滤波; 解调器,用于对经滤波的混合信号解调得到离散采样信号%。 9. The system of claim 8, wherein the receiver comprises: a low pass filter for initial analog signal s received mixed signal filtering; demodulator for the filtered mixing discrete sample signals obtained by demodulating the signal%.
  10. 10.根据权利要求9所述的系统,其特征在于,若信道间存在延时扩展,最大延时扩展为m时,该系统包括串扰幅度计算器,用于根据信道的最大延时扩展m,求出干扰信号在不同采样时刻造成的串扰幅度应: 10. The system of claim 9, wherein, if the inter-channel delay spread is present, m is the maximum delay spread, the system includes crosstalk magnitude calculator for extended m the maximum delay of the channel, obtaining the amplitude of the crosstalk interference caused by signals at different sampling time shall: 其中,i为正整数,|i|彡m,且i乒0; 所述干扰消减器根据m和众利用公式( Wherein, i is a positive integer, | i | San m, and i ping 0; utilizes the interference mitigation according to the formula m and public ( L})消除干扰信号由于延时扩展造成的串扰,其中Λ为从混合采样信号%中消除干扰信号Xk由于延时扩展造成的串扰后的有用信号。 L}) to eliminate the crosstalk due to the delay spread caused by the interference signal, wherein Λ is the elimination of the signal from the useful signal samples% after mixing crosstalk interference signals due to the delay spread caused by Xk.
  11. 11.根据权利要求10所述的系统,其特征在于,所述干扰信号识别器包括: 存储器,用于存储在接收S之前设定时间段内收到的所有帧;广播信号接收器,用于在接收混合信号s之前首先接收来自各节点的广播信号,所述广播信号包含将要发送的帧的帧编号;帧编号比较器,用于根据广播信号中的帧编号与存储器内帧的帧编号的比较结果,来识别干扰信号χ在本地是否已知。 11. The system of claim 10, wherein the interference signal identifier comprises: a memory for storing a set of all frames received prior to receiving period S; broadcast signal receiver, for received before the mixed signal s is first broadcast signal from each node, the broadcast signal comprising a frame number of the frame to be transmitted; frame number comparator for comparing the frame number of the frame within the broadcast signal in accordance with a frame number of the memory comparison, to identify whether an interference signal χ is known locally.
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EP1180868A1 (en) 2000-03-24 2002-02-20 Matsushita Electric Industrial Co., Ltd. Receiving apparatus and gain control method
CN101166205A (en) 2007-09-21 2008-04-23 上海广电(集团)有限公司中央研究院 A device and method for eliminating non related interference signals

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