WO2015070679A1

WO2015070679A1 - System for quickly synthesizing wave beams and carrier synchronization method for various sending antennas at source end thereof

Info

Publication number: WO2015070679A1
Application number: PCT/CN2014/088092
Authority: WO
Inventors: 谢宁; 梁强; 王晖; 林晓辉; 曾捷
Original assignee: 深圳大学; 谢宁; 梁强; 王晖; 林晓辉; 曾捷
Priority date: 2013-11-13
Filing date: 2014-10-02
Publication date: 2015-05-21
Also published as: CN103634895A; CN103634895B

Abstract

The present invention is applicable to the technical field of wireless communications. Provided are a system for quickly synthesizing wave beams and a carrier synchronization method for various sending antennas at a source end thereof. Sending antennas at a source end in the present invention can realize accurate time slot control, and can conduct frequency and phase estimation on a received signal and conduct estimation on phase deviation information caused by a channel time delay. The present invention takes full advantage of a broadcast characteristic of a wireless link. For each broadcast, all remaining base stations except a broadcasting base station will estimate phase values and frequency values, so that meaningless mutual interference can be avoided. In the case where a system is composed of Μ base stations, two methods are provided for realizing global synchronization. Realizing global synchronization requires M or M+1 non-overlapped time slots, and the number of time slots is greatly less than the number of time slots required by other synchronization protocols, for example, a two-way synchronization protocol requires 2M-2 non-overlapped time slots.

Description

快速波束合成***及其源端各发送天线的载波同步方法Fast beamforming system and carrier synchronization method for each transmitting antenna at the source end

技术领域Technical field

本发明属于无线通信技术领域，尤其涉及一种快速波束合成***及其源端各发送天线的载波同步方法。The present invention belongs to the field of wireless communication technologies, and in particular, to a fast beam combining system and a carrier synchronization method for each transmitting antenna at the source end.

背景技术Background technique

分布式波束合成技术是一种能够显著提高***功率效率的无线通信技术，它把分布在多个小区的独立的天线组成虚拟的天线阵(其中每个天线都有各自的晶体振荡器，且只知道自己的本地时间)，天线阵中的每个天线向目的基站节点发送相同的信号，这些信号在目的基站相干合并。由于虚拟天线阵的可扩展性和稳健性，使得分布式波束合成技术相对于传统天线阵能够获得更高的定向传输特性，相对于单天线***能够获得更大的接收信噪比(Signal Noise Ratio，SNR)增益，其应用涉及多小区协作网络、多用户无线通信***、无线传感器网络(Wireless Sensor Network，WSN)、正交频分复用(Orthogonal Frequency Division Multiplexing，OFDM)-多入多出(Multiple-Input Multiple-Output，MIMO)、3G长期演进(Long Term Evolution，LTE)等众多领域。但是由于网络中源端基站的异构性，即每个源端基站都有独立的本地振荡器、源端基站的位置以及信道传输状态的差异，使得各个源端基站的信号到达目的基站时产生相位偏移，破坏信号的合并重组，因此，源端必须对发送载波进行同步处理。Distributed beamforming technology is a wireless communication technology that can significantly improve the power efficiency of the system. It integrates independent antennas distributed in multiple cells into a virtual antenna array (each antenna has its own crystal oscillator, and only Knowing their local time), each antenna in the antenna array sends the same signal to the destination base station node, and these signals are coherently combined at the destination base station. Due to the scalability and robustness of the virtual antenna array, the distributed beamforming technology can obtain higher directional transmission characteristics than the traditional antenna array, and can obtain a larger receiving signal-to-noise ratio (Signal Noise Ratio) than the single antenna system. , SNR) gain, its application involves multi-cell cooperative network, multi-user wireless communication system, Wireless Sensor Network (WSN), Orthogonal Frequency Division Multiplexing (OFDM)-Multiple Input Multiple Output ( Multiple-Input Multiple-Output (MIMO), 3G Long Term Evolution (LTE) and many other fields. However, due to the heterogeneity of the source base stations in the network, that is, each source base station has an independent local oscillator, a location of the source base station, and a difference in channel transmission status, so that signals of each source base station arrive at the destination base station. The phase offset destroys the merge and recombination of the signal. Therefore, the source must synchronize the transmitted carrier.

源端载波同步是分布式波束合成中的关键技术，载波同步与否决定目的端接收性能的好坏，同步占用时间越少***性能越好。现有技术中适用于分布式波束合成技术、并对载波进行同步的开环方法主要有基于时分双工的往返载波同步法和双向载波同步法。前一种方法把接收到的上行信号在发送端基站中往返传输，以此来估计每个基站的相位信息实现同步，这种方法的缺点主要有(1)占用的时隙较多，对于M根天线组成的***需要2M-1个时隙实现所有基站同步，(2)这种方法只能实现载波相位的同步，不能实现载波频率的精确同步，(3)这种方法在天线发送信号之前不能实现同步，必须在接收完来自目的端的上行信号后才能开始同步，增大了***的延时；后一种方法利用同步信号在基站间的分时双向传输来估算接收信号相位，从而实现基站的载波同步，但这种方法占用的时隙数较多，对于M根天线组成的***需要2M-2个时隙实现所有基站同步。Source-side carrier synchronization is a key technology in distributed beamforming. The carrier synchronization determines whether the destination receiving performance is good or bad. The less the synchronization occupation time, the better the system performance. The open-loop methods applicable to the distributed beamforming technology and synchronizing the carriers in the prior art mainly include a time division duplex round-trip carrier synchronization method and a two-way carrier synchronization method. The former method transmits the received uplink signal to the base station of the transmitting end. Back transmission, in order to estimate the phase information of each base station to achieve synchronization, the disadvantages of this method are mainly: (1) occupying more time slots, for systems composed of M antennas, 2M-1 time slots are required to implement all base stations. Synchronization, (2) This method can only achieve the synchronization of the carrier phase, and can not achieve accurate synchronization of the carrier frequency. (3) This method can not achieve synchronization before the antenna transmits the signal, and must receive the uplink signal from the destination end. Synchronization starts, increasing the delay of the system; the latter method uses the time-division bidirectional transmission of the synchronization signal between the base stations to estimate the phase of the received signal, thereby realizing the carrier synchronization of the base station, but this method occupies more time slots. For a system composed of M antennas, 2M-2 time slots are required to achieve synchronization of all base stations.

已有的同步技术中，有的需要在满足一定条件下才能实现同步，例如当某个基站广播同步信号时，要求只有特定的基站能接收到该同步信号，如果被本来不应该接收的基站接收，就会对该基站造成干扰，增大载波估算值，这个值伴随着接下来的广播过程不断积累放大，从而影响整个***的性能。In the existing synchronization technology, some need to achieve synchronization under certain conditions. For example, when a base station broadcasts a synchronization signal, only a specific base station can receive the synchronization signal, if it is received by a base station that should not be received. This will cause interference to the base station and increase the carrier estimation value, which is accumulating and accumulating along with the subsequent broadcast process, thereby affecting the performance of the entire system.

发明内容Summary of the invention

本发明所要解决的第一个技术问题在于提供一种分布式波束合成***的源端各发送天线的载波同步方法，旨在实现源端各发送天线的载波的相位、频率同步并减少同步占用的时隙开销和相互之间干扰造成的估算值。The first technical problem to be solved by the present invention is to provide a carrier synchronization method for each transmitting antenna at the source end of a distributed beamforming system, which aims to realize phase and frequency synchronization of carriers of each transmitting antenna at the source end and reduce synchronization occupation. Estimated time slot overhead and interference between each other.

本发明是这样实现的，一种快速波束合成***的源端各发送天线的载波同步方法，所述分布式波束合成***包括源端和目的端，The present invention is implemented as a carrier synchronization method for each transmitting antenna at a source end of a fast beamforming system, where the distributed beamforming system includes a source end and a destination end.

所述源端具有M个基站，所述M个基站中包括一初级信号产生基站；所述载波同步方法包括下述步骤：The source end has M base stations, and the M base stations include a primary signal generating base station; the carrier synchronization method includes the following steps:

步骤A，初级信号产生基站在第一时隙广播所述初级信号；Step A, the primary signal generating base station broadcasts the primary signal in a first time slot;

步骤B，源端除该基站产生初级信号之外的其余所有基站均接收所述初级信号，并分别估算各自在第一时隙内接收初级信号产生的频率估算值和相位估算值； Step B: The source end receives all the base signals except the primary signal generated by the base station, and separately estimates frequency estimation values and phase estimation values respectively generated by receiving the primary signals in the first time slot;

步骤C，在之后的时隙中，其余所有基站顺次广播；在每次广播时，当前的广播基站所广播出的信号的频率为其在第一时隙的频率估算值，相位为其在前一时隙的相位估算值；而除当前的广播基站之外的其余所有基站均接收当前的广播基站所广播出的信号，并分别估算各自在当前时隙内接收广播信号而产生的相位估算值；Step C, in the subsequent time slots, all the other base stations broadcast in sequence; at each broadcast, the frequency of the signal broadcast by the current broadcast base station is its frequency estimate in the first time slot, and the phase is The phase estimation value of the previous time slot; and all the base stations except the current broadcast base station receive the signals broadcast by the current broadcast base station, and respectively estimate the phase estimation values respectively generated by receiving the broadcast signals in the current time slot. ;

步骤D，每个基站都完成广播之后，各个基站的同步后的载波频率和载波相位根据如下方式确定：Step D: After each base station completes broadcasting, the synchronized carrier frequency and carrier phase of each base station are determined as follows:

对于初级信号产生基站，将其自身载波频率值先后乘以M，得到其同步后的载波频率；将其自身载波相位值与其在除第一时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；For the primary signal generating base station, multiply its own carrier frequency value by M to obtain its synchronized carrier frequency; add its own carrier phase value to its phase estimation value of all time slots except the first time slot. , obtaining the carrier phase after synchronization;

对于除初级信号产生基站之外的其余所有基站，将各自在第一时隙的频率估算值先后乘以M，得到各自同步后的载波频率；将各自的广播时隙的前一时隙的相位估算值乘以2之后与剩下时隙的相位估算值相加，所得之和，得到各自同步后的载波相位。For all the base stations except the primary signal generating base station, the frequency estimation values of the respective first time slots are multiplied by M in order to obtain the respective synchronized carrier frequencies; the phase estimation of the previous time slot of the respective broadcast time slots is obtained. After multiplying the value by 2, the phase estimation values of the remaining time slots are added, and the resulting sum is obtained to obtain the carrier phases after the respective synchronizations.

进一步地，在步骤C和步骤D之间，所述方法还包括下述步骤C1：Further, between step C and step D, the method further comprises the following step C1:

步骤C1，在所有基站完成一次广播之后，最后广播的基站再次进行广播，在此广播时隙中，最后广播的基站所广播出的信号的频率为其在第一时隙的频率估算值的M倍，相位为其在之前所有时隙的相位估算之和；而除最后广播的基站之外的其余所有基站均接收最后广播的基站所广播出的信号，并分别估算各自在此时隙内接收广播信号而产生的相位估算值；Step C1, after all the base stations complete a broadcast, the last broadcasted base station broadcasts again. In the broadcast time slot, the frequency of the signal broadcast by the last broadcasted base station is the frequency estimate value of the first time slot. Times, the phase is the sum of the phase estimates of all previous time slots; and all the base stations except the last broadcasted base station receive the signals broadcast by the last broadcasted base station, and respectively estimate the respective reception in this time slot. a phase estimate produced by broadcasting a signal;

此时，所述步骤D替换为下述步骤E：At this time, the step D is replaced by the following step E:

步骤E，在最后广播的基站完成再次广播之后，各个基站的同步后的载波频率和载波相位根据如下方式确定：Step E: After the last broadcasted base station completes the rebroadcast, the synchronized carrier frequency and carrier phase of each base station are determined as follows:

对于同步后的载波频率，初级信号产生基站将其自身载波频率值先后乘以M-1，得到其同步后的载波频率；除初级信号产生基站之外的其余基站将各自在第一时隙的频率估算值先后乘以M-1，得到各自同步后的载波频率； For the synchronized carrier frequency, the primary signal generating base station multiplies its own carrier frequency value by M-1 to obtain its synchronized carrier frequency; the remaining base stations except the primary signal generating base station will each be in the first time slot. The frequency estimation values are multiplied by M-1 to obtain the carrier frequencies after synchronization;

对于同步后的载波相位，最后广播的基站将除其自身广播的两个时隙之外的所有时隙的相位估算值相加得到其同步后的载波相位；除最后广播的基站之外的其余基站，将各自在最后一个时隙的相位估算值减去在倒数第二个时隙的相位估算值，得到各自同步后的载波相位。For the synchronized carrier phase, the last broadcast base station adds the phase estimation values of all the slots except the two slots broadcasted by itself to obtain the synchronized carrier phase; except for the last broadcasted base station. The base station subtracts the phase estimation values in the last time slot from the phase estimation values of the last time slot, respectively, to obtain the carrier phases after the respective synchronization.

本发明所要解决的第二个技术问题在于提供一种快速波束合成***，包括源端和目的端，所述源端具有M个基站，所述M个基站中包括一初级信号产生基站；每个基站均包括频率估算单元、相位估算单元和同步单元；A second technical problem to be solved by the present invention is to provide a fast beamforming system including a source end and a destination end, the source end having M base stations, and the M base stations include a primary signal generating base station; Each of the base stations includes a frequency estimating unit, a phase estimating unit, and a synchronization unit;

所述初级信号产生基站用于产生初级信号并在第一时隙广播所述初级信号，源端除该基站产生初级信号之外的其余所有基站均接收所述初级信号，并分别通过各自的频率估算单元估算各自在第一时隙内接收初级信号产生的频率估算值、通过相位估算单元估算各自在第一时隙内接收初级信号产生的相位估算值；The primary signal generating base station is configured to generate a primary signal and broadcast the primary signal in a first time slot, and all base stations other than the base station generating a primary signal at the source end receive the primary signal and respectively pass respective frequencies The estimating unit estimates respective frequency estimation values generated by receiving the primary signals in the first time slot, and estimating, by the phase estimating unit, phase estimation values respectively generated by receiving the primary signals in the first time slot;

在之后的时隙中，其余所有基站顺次广播；在每次广播时，当前的广播基站所广播出的信号的频率为其在第一时隙的频率估算值，相位为其在前一时隙的相位估算值；而除当前的广播基站之外的其余所有基站均接收当前的广播基站所广播出的信号，并分别通过各自的频率估算单元估算各自在当前时隙内接收广播信号产生的频率估算值、通过相位估算单元估算各自在当前时隙内接收广播信号产生的相位估算值；In the subsequent time slots, all other base stations broadcast in sequence; at each broadcast, the frequency of the signal broadcast by the current broadcast base station is its frequency estimate in the first time slot, and the phase is its previous time slot. The phase estimation value; and all the base stations except the current broadcast base station receive the signals broadcast by the current broadcast base station, and respectively estimate the frequencies generated by the respective broadcast signals in the current time slot by the respective frequency estimation units. Estimating a value, estimating, by the phase estimating unit, a phase estimation value generated by each receiving a broadcast signal in a current time slot;

每个基站都完成广播之后，各个基站的同步单元通过如下方式确定各自同步后的载波频率和载波相位：After each base station completes the broadcast, the synchronization units of the respective base stations determine the carrier frequencies and carrier phases after the respective synchronizations by:

对于初级信号产生基站，其同步单元用于将其自身载波频率值先后乘以M得到其同步后的载波频率；其同步单元用于将其自身载波相位值与其在除第一时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；For a primary signal generating base station, its synchronization unit is configured to multiply its own carrier frequency value by M to obtain its synchronized carrier frequency; its synchronization unit is used to set its own carrier phase value to be other than the first time slot. The phase estimates of all time slots are added to obtain the carrier phase after synchronization;

对于除初级信号产生基站之外的其余所有基站，其同步单元用于将各自在第一时隙的频率估算值先后乘以M，得到各自同步后的载波频率；其同步单元用于将各自的广播时隙的前一时隙的相位估算值乘以2之后与剩下时隙的相位估算值相加，得到各自同步后的载波相位。 For all base stations except the primary signal generating base station, the synchronization unit is configured to multiply the respective frequency estimation values in the first time slot by M to obtain the respective synchronized carrier frequencies; the synchronization unit is used to The phase estimation value of the previous time slot of the broadcast time slot is multiplied by 2 and added to the phase estimation value of the remaining time slot to obtain the carrier phase after the respective synchronization.

进一步地，在所有基站完成一次广播之后，最后广播的基站再次进行广播，在此广播时隙中，最后广播的基站所广播出的信号的频率为其在第一时隙的频率估算值的M倍，相位为其在之前所有时隙的相位估算之和；而除最后广播的基站之外的其余所有基站均接收最后广播的基站所广播出的信号，并分别通过各自的频率估算单元估算各自在当前时隙内接收广播信号产生的频率估算值、通过相位估算单元估算各自在当前时隙内接收广播信号产生的相位估算值；Further, after all the base stations complete one broadcast, the last broadcasted base station broadcasts again, in which the frequency of the signal broadcast by the last broadcasted base station is the frequency estimate of the first time slot. Times, the phase is the sum of the phase estimates of all previous time slots; and all the base stations except the last broadcasted base station receive the signals broadcast by the last broadcasted base station, and estimate their respective frequency estimation units respectively. Receiving a frequency estimation value generated by the broadcast signal in the current time slot, and estimating, by the phase estimation unit, a phase estimation value generated by each receiving the broadcast signal in the current time slot;

在最后广播的基站完成再次广播之后，各个基站的同步单元通过如下方式确定各自同步后的载波频率和载波相位：After the last broadcasted base station completes the rebroadcast, the synchronization units of the respective base stations determine the respective synchronized carrier frequencies and carrier phases by:

对于同步后的载波频率，初级信号产生基站的同步单元将其自身载波频率值先后乘以M-1，得到其同步后的载波频率；除初级信号产生基站之外的其余基站的同步单元将各自在第一时隙的频率估算值先后乘以M-1，得到各自同步后的载波频率；For the synchronized carrier frequency, the synchronization unit of the primary signal generating base station multiplies its own carrier frequency value by M-1 to obtain the synchronized carrier frequency; the synchronization units of the remaining base stations except the primary signal generating base station will respectively The frequency estimation values in the first time slot are multiplied by M-1 to obtain the carrier frequencies after synchronization;

对于同步后的载波相位，最后广播的基站的同步单元将除其自身广播的两个时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；除最后广播的基站之外的其余基站的同步单元，将各自在最后一个时隙的相位估算值减去在倒数第二个时隙的相位估算值，得到各自同步后的载波相位。For the synchronized carrier phase, the synchronization unit of the last broadcast base station adds the phase estimation values of all the slots except the two slots broadcasted by itself to obtain the synchronized carrier phase; The synchronization units of the remaining base stations are subtracted from the phase estimation values of the last time slot by the phase estimation values of the last time slot to obtain the respective synchronized carrier phases.

本发明充分利用了无线链路的广播特性，对于每次广播，除广播基站之外的其余所有基站都会估算相位值和频率值，可避免无谓的相互干扰，对于M个基站组成的***情况下，实现全局同步需要M不重叠的时隙，大大少于其余同步协议所需要的时隙数，例如Two-way同步协议需要的2M-2个非重叠时隙。The invention fully utilizes the broadcast characteristics of the wireless link. For each broadcast, all the base stations except the broadcast base station estimate the phase value and the frequency value, thereby avoiding unnecessary mutual interference, for the system system composed of M base stations. To achieve global synchronization, M slots that do not overlap are required, which is much less than the number of slots required by the remaining synchronization protocols, such as 2M-2 non-overlapping slots required by the Two-way synchronization protocol.

附图说明DRAWINGS

图1是本发明提供的快速波束合成***的源端各发送天线的载波同步方法的实现流程图；1 is a flowchart of implementing a carrier synchronization method for each transmitting antenna at a source end of a fast beam combining system provided by the present invention;

图2是本发明实施例一提供的三个源端基站分布式合作波束形成示意图；2 is a schematic diagram of distributed cooperative beamforming of three source base stations according to Embodiment 1 of the present invention;

图3是本发明实施例二提供的三个源端基站分布式合作波束形成示意图； 3 is a schematic diagram of distributed cooperative beamforming of three source base stations according to Embodiment 2 of the present invention;

图4是本发明提供的快速波束合成***中源端各基站的逻辑结构图。4 is a logical structural diagram of base stations at the source end in the fast beamforming system provided by the present invention.

具体实施方式detailed description

为了使本发明的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本发明进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

本发明中，对于M个基站组成的***情况下，在实施例一中，实现全局同步需要M不重叠的时隙，以确保在每次广播过程中没有互相干扰。如果任何一个源端基站到剩下所有源端基站的信道相位之和等于另外任意一个源端基站节点到剩下所有源端基站的信道相位之和相等，就可以实现所有源端基站同步，即通过实施例一可以实现一个完美的同步，详见下文所描述。实施例二可以放松在实施一这样的限制(即上文描述的“任何一个源端基站到剩下所有源端基站的信道相位之和等于另外任意一个源端基站到剩下所有源端基站的信道相位的和相等”)，但它需要M+1不重叠的时隙。然而，相比传统的协议相比，主要是两个实施例提出的协议减少非重叠时隙数，例如，在Two-way同步协议中，需要2M-2个非重叠的时隙，这意味着两个提出协议大大节省同步开销。In the present invention, in the case of a system composed of M base stations, in the first embodiment, global synchronization is required to require time slots in which M does not overlap, to ensure that there is no mutual interference in each broadcast process. If the sum of the channel phases of any one of the source base stations to all the remaining source base stations is equal to the sum of the channel phases of any other source base station node to all the remaining source base stations, all source base station synchronization can be achieved, that is, A perfect synchronization can be achieved by the first embodiment, as described in detail below. Embodiment 2 may relax in implementing such a limitation (ie, the above description "the sum of the channel phases of any one of the source base stations to all the remaining source base stations is equal to any other source base station to all the remaining source base stations. The sum of the channel phases is equal"), but it requires time slots where M+1 does not overlap. However, compared to the conventional protocol, mainly the protocol proposed by the two embodiments reduces the number of non-overlapping time slots. For example, in the Two-way synchronization protocol, 2M-2 non-overlapping time slots are required, which means The two proposed protocols greatly save synchronization overhead.

步骤A，初级信号产生基站节点产生一初级信号，并在第一时隙广播此初级信号。In step A, the primary signal generating base station node generates a primary signal and broadcasts the primary signal in the first time slot.

如图2所示，第一个源端基站节点N₁产生一个初级信号，并在第一个时隙TS₁广播这个信号。然后剩下所有的源端基站{N₂，…，N_M}接收这个初级信号。As shown in Figure 2, the first source base station node N ₁ generates a primary signal and broadcasts this signal in the first time slot TS ₁ . Then all the source base stations {N ₂ , . . . , N _M } are left to receive this primary signal.

步骤B，源端除该基站产生初级信号之外的其余所有基站均接收所述初级信号，并分别估算各自在第一时隙内接收初级信号产生的频率估算值和相位估算值。Step B: The source end receives all the base signals except the base station generates the primary signal, and separately estimates the frequency estimation value and the phase estimation value respectively generated by receiving the primary signal in the first time slot.

步骤C，在之后的时隙中，其余所有基站顺次广播；在每次广播时，当前的广播基站所广播出的信号的频率为其在第一时隙的频率估算值，相位为其在前一时隙的相位估算值；而除当前的广播基站之外的其余所有基站均接收当前的广播基站所广播出的信号，并分别估算各自在当前时隙内接收广播信号而产生的相位估算值。Step C, in the subsequent time slots, all the other base stations broadcast in sequence; at each broadcast, the frequency of the signal broadcast by the current broadcast base station is its frequency estimate in the first time slot, and the phase is Phase estimate of the previous time slot; and all base stations except the current broadcast base station receive the current Broadcasting the signals broadcast by the base station and estimating the phase estimates respectively generated by receiving the broadcast signals in the current time slot.

其余所有的基站顺次广播，是通过增加源端基站节点指数N₂→N₃→…→N_M，其中每一次广播的信号都是前一时隙接收信号的周期延拓，且所有剩下的源端基站节点可以接收到的这个信号。All other base stations broadcast in sequence by increasing the source base station node index N ₂ → N ₃ →... → N _M , wherein each broadcasted signal is a periodic extension of the received signal of the previous time slot, and all remaining This signal can be received by the source base station node.

对于初级信号产生基站，将其自身载波频率值先后乘以M得到其同步后的载波频率；将其自身载波相位值与其在除第一时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；For the primary signal generating base station, multiply its own carrier frequency value by M to obtain its synchronized carrier frequency; add its own carrier phase value to its phase estimation value of all time slots except the first time slot, Obtaining the carrier phase after synchronization;

对于除初级信号产生基站之外的其余所有基站，将各自在第一时隙的频率估算值先后乘以M，得到各自同步后的载波频率；将各自的广播时隙的前一时隙的相位估算值乘以2之后与剩下时隙的相位估算值相加，得到各自同步后的载波相位。For all the base stations except the primary signal generating base station, the frequency estimation values of the respective first time slots are multiplied by M in order to obtain the respective synchronized carrier frequencies; the phase estimation of the previous time slot of the respective broadcast time slots is obtained. After multiplying the value by 2, the phase estimation values of the remaining time slots are added to obtain the carrier phases after the respective synchronization.

下文结合图2以实施例一为例进行说明。Hereinafter, the first embodiment will be described with reference to FIG. 2 as an example.

A1协议原理Principle of A1 protocol

a)在TS₁时隙，基站节点N₁广播初级信号，我们把所有发送信号的幅度都设置成1，于是基站节点N₁发送的初级信号表示为：a) In the TS ₁ time slot, the base station node N ₁ broadcasts the primary signal, we set the amplitude of all the transmitted signals to 1, and then the primary signal transmitted by the base station node N ₁ is expressed as:

其中

表示基站节点N₁在TS₁时隙的发送间隔，ω₁和φ₁分别表示N₁的初始频率和相位，j表示复数。among them

Indicates the transmission interval of the base station node N ₁ in the TS ₁ time slot, ω ₁ and φ ₁ respectively represent the initial frequency and phase of N ₁ , and j denotes a complex number.

这个信号经过LTI信道传输后到达剩下所有的源端基站节点{N₂，…，N_M}，为了符号表示方便，我们可以用N_k表示：This signal is transmitted through the LTI channel and reaches all the remaining source base station nodes {N ₂ ,..., N _M }. For the convenience of symbolic representation, we can use N _{k to} indicate:

其中k＝2，3，…，M。

表示基站节点N_k在TS₁时隙的接收间隔，α_1，k和

分别表示当频率为ω₁时基站节点N_k和基站节点N₁之间的信道延时相位，

分别表示基站节点N_k在TS₁时隙的接收噪声，Δ₁、Δ_k分别表示在N₁、N_k基站是一个零均值低通随机过程，主要获取固定时间偏移、本地振荡器相位噪声、振荡器频率不稳定带来的影响。β₁、β_k分别是在N₁、N_k基站相对与参数时间的实际时钟系数。基站节点N_k对接收信号的频率和相位进行估算，表示为：Where k=2,3,...,M.

Representing the reception interval of the base station node N _k in the TS ₁ time slot, α _{1, k} and

Representing the channel delay phase between the base station node N _k and the base station node N ₁ when the frequency is ω ₁ , respectively.

Respectively indicating the reception noise of the base station node N _k in the TS ₁ time slot, Δ ₁ , Δ _k respectively indicate that the N ₁ , N _k base station is a zero-mean low-pass random process, mainly acquiring fixed time offset, local oscillator phase noise. The effect of unstable oscillator frequency. β ₁ and β _k are the actual clock coefficients of the relative time and parameter time of the N ₁ and N _k base stations, respectively. The base station node N _k estimates the frequency and phase of the received signal, expressed as:

和

分别表示基站N_k在TS₁时隙的频率估算值和相位估算值。

with

The frequency estimation value and phase estimation value of the base station N _k in the TS ₁ time slot are respectively indicated.

b)在TS₂时隙，基站N₂把在TS₁时隙接收的同步信号广播出去，这个信号表示为：b) In the TS ₂ time slot, the base station N ₂ broadcasts the synchronization signal received in the TS ₁ time slot. This signal is expressed as:

其中

表示基站N₂在TS₂时隙的发送间隔，

和

分别表示基站N₂在TS₁时隙的估算频率和相位(公式(3)和(4))，这个信号经LTI信道传输后被剩下所有源端基站接收，用N_k表示，此时接收信号表示为：among them

Indicates the transmission interval of the base station N ₂ in the TS ₂ slot.

with

Respectively indicate the estimated frequency and phase of the base station N ₂ in the TS ₁ time slot (equations (3) and (4)). This signal is transmitted by the LTS channel and then received by all the source base stations, denoted by N _k , and received at this time. The signal is expressed as:

其中k＝1，3，…，M。

表示基站N_k在TS₂时隙的接收间隔，这时基站N_k产生相位估计可以表示为：Where k=1,3,...,M.

Representing the reception interval of the base station N _k in the TS ₂ time slot, at which time the base station N _k generates a phase estimate which can be expressed as:

表示基站N_k在TS₂时隙的相位估算值。

It represents the phase estimate at the base station N _k slot TS _2.

c)在TS_i时隙，上述过程继续通过增加源端基站的指数。每个基站都重复之前的行为，接收前一时隙的预同步信号用于载波信息估计，并在下一时隙把这个信号广播出去。 c) In the TS _i time slot, the above process continues by increasing the index of the source base station. Each base station repeats the previous behavior, receives the pre-synchronization signal of the previous time slot for carrier information estimation, and broadcasts this signal in the next time slot.

在TS_i时隙广播信号表示为：The broadcast signal in the TS _i time slot is expressed as:

其中

表示在TS₁时隙N_i基站的频率估计，

表示基站N_i在TS_i-1时隙的相位估计。此信号经LTI信道传输后，被剩下所有源端基站接收，用N_k表示，此时接收信号表示为：among them

Representing the frequency estimate of the base station in the TS ₁ slot N _i ,

Indicates the phase estimate of the base station N _i in the TS _i-1 time slot. After the signal is transmitted through the LTI channel, it is received by all the source base stations remaining, and is represented by N _k . At this time, the received signal is expressed as:

其中k＝1，2，…，M(k≠i)，

表示基站N_k在TS_i时隙的接收间隔，这时基站N_k产生相位估计可以表示为：Where k=1,2,...,M(k≠i),

Indicates the reception interval of the base station N _k in the TS _i time slot, at which time the base station N _k generates a phase estimate which can be expressed as:

表示基站N_k在TS_i时隙的相位估算值。

Indicates the phase estimate of the base station N _k in the TS _i time slot.

d)在TS_M时隙，基站N_M把在TS_M-1时隙接收的同步信号广播出去，这个信号表示为：d) In the TS _M time slot, the base station N _M broadcasts the synchronization signal received in the TS _M-1 time slot. This signal is expressed as:

其中

表示在TS₁时隙N_M基站的频率估计，

表示基站节点N_M在TS_M-1时隙的相位估计。此信号经LTI信道传输后，被剩下所有源端基站接收，用N_k表示，此时接收信号表示为：among them

Representing the frequency estimate of the N _M base station in TS ₁ time slot,

Represents the phase estimate of the base station node N _M in the TS _M-1 time slot. After the signal is transmitted through the LTI channel, it is received by all the source base stations remaining, and is represented by N _k . At this time, the received signal is expressed as:

其中k＝1，2，…，M-1，

表示基站N_M在TS_M时隙的接收间隔，这时基站N_M产生相位估计可以表示为：Where k=1, 2,..., M-1,

Indicates the receiving interval of the base station N _M in the TS _M time slot, at which time the base station N _M generates a phase estimate which can be expressed as:

表示基站N_M在TS_M时隙的相位估算值。

Indicates the phase estimate of the base station N _M in the TS _M time slot.

B1，在实施例一的协议中从本地估计中合成同步本地振荡器B1, synthesizing a synchronous local oscillator from local estimation in the protocol of the first embodiment

在传播阶段，每个源端基站接收初级信号，同时形式相位和频率估计，实施例一的协议对于N_k基站，合成了同步本地振荡器SLO，构建同步信号：In the propagation phase, each source base station receives the primary signal, and the form phase and frequency estimate. The protocol of the first embodiment synthesizes the synchronous local oscillator SLO for the N _k base station to construct a synchronization signal:

其中

和

是实施例一的协议的SLO频率和相位，如果我们假设在基站节点N_k是理想的，也就是说没有任何估计值，这时SLO频率

和相位

分别表示为：among them

with

Is the SLO frequency and phase of the protocol of the first embodiment, if we assume that the base station node N _k is ideal, that is to say without any estimated value, then the SLO frequency

And phase

Expressed as:

这时，实施例一的协议N_k(k＝1，2，…，M)的SLO信号以参考时间t表示：At this time, the SLO signal of the protocol N _k (k=1, 2, . . . , M) of the first embodiment is represented by the reference time t:

此时可以有这样一个设想：如果任何一个源端基站到剩下所有源端基站的信道相位的和等于另外任意一个源端基站到剩下所有源端基站的信道相位的和相等，可以表示为：At this point, there may be an idea that if the sum of the channel phases of any one of the source base stations to all the remaining source base stations is equal to the sum of the channel phases of any other source base station to all the remaining source base stations, it can be expressed as :

这时实施例一的协议实现所有源端基站全部同步。At this time, the protocol of Embodiment 1 implements all the synchronization of all source base stations.

证明：我们把(18)带入到(17)中，可以得到：Proof: We bring (18) to (17) and we can get:

既然在(19)式中没有k的函数，在提议1中已经证明。因此，尽管N_k拥有本地时间和操作仅仅依靠本地估计，实施例一的协议同步实现之后，在网络中每个源端基站N_kSLO频率是相同的，其SLO相位也与其它相位相同。 Since there is no function of k in (19), it has been proved in proposal 1. Therefore, although N _k has local time and operation relies solely on local estimation, after the protocol synchronization implementation of Embodiment 1, the frequency of each source base station N _k SLO in the network is the same, and its SLO phase is also the same as the other phases.

如果网络满足(18)的条件，表明通信网络应该是构建良好的，那么第一个提议达到完美同步。这样实施例一的协议的功能在很大程度上依赖于源端基站节点拓扑的变化。对于任意拓扑结构，实施例一的协议可能仅在满足条件下才能达到相位同步。为了克服这个条件限制，我们提出实施例二的协议，借助于在实施例一的协议同步的基础上，仅仅增加一个时隙。If the network satisfies the condition of (18), indicating that the communication network should be well constructed, then the first proposal achieves perfect synchronization. The function of the protocol of the first embodiment is largely dependent on the change of the source base station node topology. For any topology, the protocol of Embodiment 1 may only achieve phase synchronization if the conditions are met. In order to overcome this conditional limitation, we propose the protocol of the second embodiment, by adding only one time slot on the basis of the protocol synchronization in the first embodiment.

基于上述考虑，在步骤C和步骤D之间，所述方法还可以进一步包括下述步骤C1：Based on the above considerations, between step C and step D, the method may further comprise the following step C1:

对于同步后的载波频率，初级信号产生基站将其自身载波频率值先后乘以M-1，得到其同步后的载波频率；除初级信号产生基站之外的其余基站将各自在第一时隙的频率估算值先后乘以M-1，得到各自同步后的载波频率；For the synchronized carrier frequency, the primary signal generating base station multiplies its own carrier frequency value by M-1 to obtain its synchronized carrier frequency; the remaining base stations except the primary signal generating base station will each be in the first time slot. The frequency estimation values are multiplied by M-1 to obtain the carrier frequencies after synchronization;

对于同步后的载波相位，最后广播的基站将除其自身广播的两个时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；除最后广播的基站之外的其余基站，将各自在最后一个时隙的相位估算值减去在倒数第二个时隙的相位估算值，，得到各自同步后的载波相位。For the synchronized carrier phase, the last broadcasted base station adds the phase estimation values of all the time slots except the two time slots broadcast by itself to obtain the synchronized carrier phase; except for the last broadcasted base station. The remaining base stations subtract the phase estimates of the last time slot from the phase estimates of the last time slot to obtain the respective synchronized carrier phases.

下文结合图3以实施例二为例进行说明。The second embodiment will be described below with reference to FIG. 3 as an example.

A2协议原理Principle of A2 protocol

a)从TS₁到TS_M时隙a) From the time slot TS ₁ to TS _M

实施例二的协议从TS₁到TS_M时隙同步过程与实施例一的协议同步过程保持完全相同。The protocol of the second embodiment is completely identical to the protocol synchronization process of the first embodiment from the TS ₁ to the TS _M slot synchronization process.

b)在TS_M+1时隙，基站N_M在TS_M+1时隙再次把同步信号广播出去，这个信号表示为：b) In the TS _M+1 time slot, the base station N _M broadcasts the synchronization signal again in the TS _M+1 time slot. This signal is expressed as:

其中

表示基站N_k在TS_M+1时隙的发射间隔，其频率

和相位

分别为：among them

Indicates the transmission interval of the base station N _k in the TS _M+1 time slot, the frequency

And phase

They are:

剩下所有源端基站再次接受此信号，用N_k表示：All remaining source base stations accept this signal again, denoted by N _k :

其中k＝1，2，…，M-1，

是N_K源端基站在

时隙接受信号间隔。这时N_k产生相位估计表示为：Where k=1, 2,..., M-1,

Is the N _K source base station at

The time slot accepts the signal interval. At this time, the phase estimate of N _k is expressed as:

表示基站N_k在TS_M+1时隙的相位估算值。 Indicates the phase estimate of the base station _Nk in the TS _M+1 time slot.

B2，在实施例二的协议中从本地估计中合成同步本地振荡器B2, synthesizing a synchronous local oscillator from local estimation in the protocol of the second embodiment

除了最后一个源端基站之外，剩下所有源端基站接收在TS_M+1时隙信号，进行相位估计和频率估计之后，实施例二的协议合成了同步本地振荡器SLO，N_k构建同步信号：Except for the last source base station, after all the source base stations receive the TS _M+1 time slot signal for phase estimation and frequency estimation, the protocol of the second embodiment synthesizes the synchronous local oscillator SLO, N _k constructs synchronization. signal:

其中

和

分别是实施例二的协议SLO频率和相位，可以表示为：among them

with

The protocol SLO frequency and phase of the second embodiment are respectively expressed as:

这时，实施例二的协议N_k(k＝1，2，…，M)的SLO信号以参考时间t表示，有：At this time, the SLO signal of the protocol N _k (k=1, 2, . . . , M) of the second embodiment is represented by the reference time t, and has:

既然在(28)式中没有k的函数，实施例二的协议同步实现之后，所以在网络中每个源端基站节点N_kSLO频率是相同的，其SLO相位也与其它相位相同。无论(18)这个条件是否满足，但是实施例二的协议能够实现完美的同步。Since there is no function of k in the equation (28), after the protocol of the second embodiment is synchronously implemented, the frequency of each source base station node N _k SLO is the same in the network, and the SLO phase is also the same as the other phases. Whether or not the condition of (18) is satisfied, the protocol of the second embodiment can achieve perfect synchronization.

综合上述两个实施例，可以看出：在实施例一的协议同步的过程是由第一个源端基站N₁产生一个初级信号，并在第一个时隙TS₁广播这个信号，然后剩下所有的源端基站{N₂，…，N_M}接收这个初级信号。剩下所有的基站顺次广播，是通过增加源端基站节点指数N₂→N₃→…→N_M，其中每一次广播的信号都是前一时隙接收信号的周期延拓，且所有剩下的源端基站可以接收到的这个信号。在TS_M时隙，实施例一的协议完成它的同步过程。对于实施例二的协议，同步的过程在前M个时隙与实施例一的协议保持一样，但是第M个源N_M基站产生第二个初级信号，在第M+1时隙TS_M+1广播这个信号，除了N_M基站节点外，所有剩下源端基站节点接收第二个初级信号，并且实施例二的协议在这个TS_M+1时隙完成同步。下文以三个源端基站为例来进行分布式波束形成的性能分析，其余节点数目的***同理可推。The above two embodiments, it can be seen: in a process embodiment of the synchronization protocol is to generate a primary signal source base station by the first N _1, and the first time slot TS ₁ the broadcast signal and then left All of the source base stations {N ₂ , . . . , N _M } receive this primary signal. All the remaining base stations broadcast in sequence by increasing the source base station node index N ₂ →N ₃ →...→N _M , wherein each broadcasted signal is the periodic extension of the received signal of the previous time slot, and all remaining This signal can be received by the source base station. In the TS _M time slot, the protocol of the first embodiment completes its synchronization process. For the protocol of the second embodiment, the synchronization process remains the same as the protocol of the first embodiment in the first M time slots, but the Mth source _MN base station generates the second primary signal, in the M+1 time slot TS _{M+ 1} Broadcast this signal, except for the N _M base station node, all remaining source base station nodes receive the second primary signal, and the protocol of the second embodiment completes the synchronization in this TS _M+1 time slot. The performance analysis of distributed beamforming is performed by taking three source base stations as an example. The system of the remaining nodes can be pushed in the same way.

本发明分析提出在波束形成时隙两个载波同步协议的性能，根据在目的基站节点载波相位偏差，包括估计值和振荡器相位噪声。在此主要分析三个源端基站节点M＝3情况，这个分析也可以被运用到M＞3源端基站节点的场景。为了比较它们性能，除了提出上述两个实施例之外，传统的Two-way协议也将给出。The present invention analyzes the performance of two carrier synchronization protocols in a beamforming time slot, including the estimated value and oscillator phase noise based on the carrier phase offset at the destination base station node. Here, the three source base station nodes M=3 are mainly analyzed. This analysis can also be applied to the scenario where M>3 source base station nodes. In order to compare their performance, in addition to the above two embodiments, the traditional Two-way protocol will also be given.

首先，对于实施例一，参照图2：First, for the first embodiment, refer to FIG. 2:

a)在TS₁时隙，基站N₁广播初级信号，我们把所有发送信号的幅度都设置成1，于是基站节点N₁发送的初级信号表示为： a) In the TS ₁ time slot, the base station N ₁ broadcasts the primary signal, we set the amplitude of all the transmitted signals to 1, and then the primary signal transmitted by the base station node N ₁ is expressed as:

其中

表示基站N₁在TS₁时隙的发送间隔，ω₁和φ₁分别表示N₁的初始频率和相位。among them

Indicates the transmission interval of the base station N ₁ in the TS ₁ time slot, and ω ₁ and φ ₁ respectively represent the initial frequency and phase of N ₁ .

这个信号经过LTI信道传输后被N₂和N₃接收，可以表示为：This signal is transmitted by N ₂ and N ₃ after being transmitted through the LTI channel and can be expressed as:

其中k＝2，3，

表示基站N_k在TS₁时隙的接收间隔，因此，基站N_k对接收信号的频率和相位进行估算，表示为：Where k=2,3,

Indicates the reception interval of the base station N _k in the TS ₁ time slot. Therefore, the base station N _k estimates the frequency and phase of the received signal, which is expressed as:

其中k＝2，3，

和

分别表示基站N_k在TS₁时隙的频率估算值和相位估算值。Where k=2,3,

with

其中

表示基站N₂在TS₂时隙的发送间隔，

和

分别表示基站N₂在TS₁时隙的估算频率和相位(公式(31)和(32))，这个信号经LTI信道传输后被源端基站N₁和N₃接收，此时接收信号表示为：among them

with

Respectively indicate the estimated frequency and phase of the base station N ₂ in the TS ₁ time slot (equations (31) and (32)). This signal is transmitted by the source base stations N ₁ and N ₃ after being transmitted through the LTI channel, and the received signal is represented as :

其中k＝1，3，

表示基站N_k在TS₂时隙的接收间隔，这时基站N₁和N₃分别产生相位估计可以表示为：Where k=1,3,

Representing the reception interval of the base station N _k in the TS ₂ time slot, at which time the base stations N ₁ and N ₃ respectively generate phase estimates which can be expressed as:

c)在TS₃时隙，源端基站N₃发射信号给源端基站N₁和N₂，这时源端基站节点N₃发射信号表示为：c) In the TS ₃ time slot, the source base station N ₃ transmits a signal to the source base stations N ₁ and N ₂ , at which time the source base station node N ₃ transmits a signal expressed as:

其中

表示基站N₃在TS₃时隙的发送间隔，

和

分别表示基站N₃本地估算频率和相位(公式(31)和(36))，这个信号经LTI信道传输后被源端基站N₁和N₂接收，此时接收信号表示为：among them

Indicates the transmission interval of the base station N ₃ in the TS ₃ time slot,

with

Respectively, the base station N ₃ locally estimates the frequency and phase (equations (31) and (36)). This signal is transmitted by the source base stations N ₁ and N ₂ after being transmitted through the LTI channel. At this time, the received signal is expressed as:

其中k＝1，2，

表示基站N_k在TS₃时隙的接收间隔，这时基站N₁和N₂分别产生相位估计可以表示为：Where k=1, 2,

Representing the reception interval of the base station N _k in the TS ₃ time slot, at which time the base stations N ₁ and N ₂ respectively generate phase estimates which can be expressed as:

根据信道互易性

并且满足(18)条件，可以表示为：Channel reciprocity

And satisfy the condition of (18), which can be expressed as:

我们构造实施例一的协议产生的SLO频率和相位：

We construct the SLO frequency and phase generated by the protocol of Example 1:

d)在TS₄时隙，在TDD上行信道中，移动台在

时刻发射上行信号，这个信号表示为：d) in the TS ₄ time slot, in the TDD uplink channel, the mobile station is

The uplink signal is transmitted at the moment, and the signal is expressed as:

其中ω₀表示上行信号的频率。在通信网络中这个信号被源端基站N_k(k＝1，2，3)接收，这里假设***中的所有基站都拥有下行传输信号的拷贝，这些拷贝信号是MSC通过蜂窝网络回程线路传递给各个基站。源端基站N_k接收目的基站在

时刻接收的上行信号，表示为：Where ω ₀ represents the frequency of the upstream signal. In the communication network, this signal is received by the source base station N _k (k = 1, 2, 3), assuming that all base stations in the system have copies of the downlink transmission signals, which are transmitted by the MSC to the backhaul line of the cellular network. Each base station. The source base station N _k receives the destination base station at

The uplink signal received at the moment is expressed as:

源端基站N_k对接收信号进行频率和相位估算：The source base station N _k performs frequency and phase estimation on the received signal:

其中k＝1，2，3，

和

分别是频率和相位估算值。Where k=1, 2, 3,

with

They are frequency and phase estimates, respectively.

e)在TS₅时隙，源端基站N_k(k＝1，2，3)，，使用本地载波估算值

和

以及SLO频率

和相位

合成实施例一的协议下行信号，根据公式：e) in the TS ₅ time slot, the source base station N _k (k = 1, 2, 3), using the local carrier estimate

with

And SLO frequency

And phase

The protocol downlink signal of the first embodiment is synthesized according to the formula:

我们把这个三个源端基站公式化成参考时间，其中

表示三个源端基站N_k(k＝1，2，3)的间隔：We formulate these three source base stations into reference time, where

Indicates the interval between three source base stations N _k (k=1, 2, 3):

在下行信号传播之后，目的基站总的信号(参考时间)表示为：After the downlink signal is transmitted, the total signal (reference time) of the destination base station is expressed as:

为了简单表示，我们暂时假设a_k，0＝1和

Eq.(53)能简化为：For the sake of simplicity, we temporarily assume a _k,0 =1 and

Eq. (53) can be simplified to:

如果我们忽略频率估算值，相位估算值和噪声，并且满足(18)条件，实现在目的基站同步，等式(54)可以进行简化： If we ignore the frequency estimate, the phase estimate and the noise, and satisfy the condition (18) to achieve synchronization at the destination base station, equation (54) can be simplified:

其次，对于实施例二，参照图3：Second, for the second embodiment, refer to FIG. 3:

为了克服(18)条件限制，我们提出实施例二的协议仅在实施例一的协议基础上增加一个时隙。In order to overcome the (18) conditional limitation, we propose that the protocol of the second embodiment adds only one time slot based on the protocol of the first embodiment.

a)从TS₁到TS₃时隙a) Time slot from TS ₁ to TS ₃

实施例二的协议从TS₁到TS₃时隙同步过程与实施例一的协议同步过程保持完全相同。The protocol synchronization procedure of the second embodiment from the TS ₁ to the TS ₃ slot synchronization process remains identical to the protocol synchronization process of the first embodiment.

b)在TS₄时隙，基站N₃在TS₄时隙再次把同步信号广播出去，这个信号表示：b) In the TS ₄ time slot, the base station N ₃ broadcasts the synchronization signal again in the TS ₄ time slot. This signal indicates:

其中among them

和

分别表示基站N₃本地估算频率和相位，这个信号经LTI信道传输后被源端基站N₁和N₂接收，此时接收信号表示为：

with

Respectively indicating the local estimated frequency and phase of the base station N ₃ , this signal is transmitted by the source base stations N ₁ and N ₂ after being transmitted through the LTI channel, and the received signal is represented as:

其中k＝1，2，因此N₁和N₂产生相位估算分别表示为： Where k = 1, 2, so the phase estimates of N ₁ and N ₂ are expressed as:

现在我们构造实施例二的协议产生的SLO频率和相位：Now we construct the SLO frequency and phase generated by the protocol of Example 2:

c)在TS₅时隙，在TDD上行信道中，移动台在

时刻发射上行信号，这个信号表示为： c) in the TS ₅ time slot, in the TDD uplink channel, the mobile station is

The uplink signal is transmitted at the moment, and the signal is expressed as:

其中ω₀表示上行信号的频率。在通信网络中这个信号被源端基站N_k(k＝1，2，3)接收，这里假设***中的所有基站都拥有下行传输信号的拷贝，这些拷贝信号是MSC通过蜂窝网络回程线路传递给各个基站节点。源端基站N_k接收目的基站节点在

时刻接收的上行信号，表示为：Where ω ₀ represents the frequency of the upstream signal. In the communication network, this signal is received by the source base station N _k (k = 1, 2, 3), assuming that all base stations in the system have copies of the downlink transmission signals, which are transmitted by the MSC to the backhaul line of the cellular network. Each base station node. The source base station _Nk receives the destination base station node at

The uplink signal received at the moment is expressed as:

源端基站节点N_k对接收信号进行频率和相位估算：The source base station node N _k performs frequency and phase estimation on the received signal:

其中k＝1，2，3，

和

分别是频率和相位估算值。Where k=1, 2, 3,

with

They are frequency and phase estimates, respectively.

e)在TS₆时隙，源端基站N_k(k＝1，2，3)，，使用本地载波估算值

和

以及SLO频率

和相位

合成实施例二的协议下行信号，根据公式：e) in the TS ₆ time slot, the source base station N _k (k = 1, 2, 3), using the local carrier estimate

with

And SLO frequency

And phase

The protocol downlink signal of the second embodiment is synthesized according to the formula:

我们把这个三个源端节点公式化成参考时间，其中

表示三个源端基站N_k(k＝1，2，3)的间隔：We formulate these three source nodes into reference time, where

Indicates the interval between three source base stations N _k (k=1, 2, 3):

为了简单表示，我们暂时假设a_k，0＝1和

Eq.(74)能简化为： For the sake of simplicity, we temporarily assume a _k,0 =1 and

Eq. (74) can be simplified to:

如果我们忽略频率估算值，相位估算值和噪声，并且不满足(18)条件，目的基站能实现同步，等式(75)可以进行简化：If we ignore the frequency estimate, the phase estimate and the noise, and do not satisfy the condition (18), the destination base station can achieve synchronization, and equation (75) can be simplified:

本发明还提供了一种快速波束合成***，包括源端和目的端，所述源端具有M个基站，所述M个基站中包括一初级信号产生基站。如图4所示，每个基站N均包括频率估算单元、相位估算单元和同步单元(需要说明的是，图4仅示出了与本发明相关的逻辑部分)。The invention also provides a fast beamforming system, comprising a source end and a destination end, wherein the source end has M base stations, and the M base stations comprise a primary signal generating base station. As shown in FIG. 4, each base station N includes a frequency estimating unit, a phase estimating unit, and a synchronizing unit (it is to be noted that FIG. 4 only shows the logic portion related to the present invention).

与上文所述的方法相对应，初级信号产生基站用于产生初级信号并在第一时隙广播所述初级信号，源端除该基站产生初级信号之外的其余所有基站均接收所述初级信号，并分别通过各自的频率估算单元估算各自在第一时隙内接收初级信号产生的频率估算值、通过相位估算单元估算各自在第一时隙内接收初级信号产生的相位估算值。Corresponding to the method described above, the primary signal generating base station is configured to generate the primary signal and broadcast the primary signal in the first time slot, and all the base stations other than the base station generating the primary signal at the source end receive the primary signal And estimating, by the respective frequency estimating units, frequency estimation values respectively generated by receiving the primary signals in the first time slot, and estimating, by the phase estimating unit, phase estimation values respectively generated by receiving the primary signals in the first time slot.

在之后的时隙中，其余所有基站顺次广播；在每次广播时，当前的广播基站所广播出的信号的频率为其在第一时隙的频率估算值，相位为其在前一时隙的相位估算值；而除当前的广播基站之外的其余所有基站均接收当前的广播基站所广播出的信号，并分别通过各自的频率估算单元估算各自在当前时隙内接收广播信号产生的频率估算值、通过相位估算单元估算各自在当前时隙内接收广播信号产生的相位估算值。In the subsequent time slots, all other base stations broadcast in sequence; at each broadcast, the frequency of the signal broadcast by the current broadcast base station is its frequency estimate in the first time slot, and the phase is its previous time slot. The phase estimation value; and all the base stations except the current broadcast base station receive the signals broadcast by the current broadcast base station, and respectively estimate the respective receiving in the current time slot by the respective frequency estimating units. The frequency estimation value generated by the broadcast signal is estimated by the phase estimating unit to estimate the phase estimation value generated by receiving the broadcast signal in the current time slot.

作为实施例一，每个基站都完成广播之后，各个基站的同步单元通过如下方式确定各自同步后的载波频率和载波相位：对于初级信号产生基站，其同步单元用于将其自身载波频率值先后乘以M，得到其同步后的载波频率；其同步单元用于将其自身载波相位值与其在除第一时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；对于除初级信号产生基站之外的其余所有基站，其同步单元用于将各自在第一时隙的频率估算值先后乘以M，得到各自同步后的载波频率；其同步单元用于将各自的广播时隙的前一时隙的相位估算值乘以2之后与剩下时隙的相位估算值相加，得到各自同步后的载波相位。As a first embodiment, after each base station completes broadcasting, the synchronization unit of each base station determines the carrier frequency and carrier phase of each synchronization after: for the primary signal generating base station, the synchronization unit is used to sequentially set its own carrier frequency value. Multiplying by M to obtain its synchronized carrier frequency; its synchronization unit is used to add its own carrier phase value to its phase estimate of all time slots except the first time slot to obtain its synchronized carrier phase. For all base stations except the primary signal generating base station, the synchronization unit is configured to multiply the respective frequency estimation values in the first time slot by M to obtain the respective synchronized carrier frequencies; the synchronization unit is used to The phase estimation value of the previous time slot of the broadcast time slot is multiplied by 2 and added to the phase estimation value of the remaining time slot to obtain the carrier phase after the respective synchronization.

作为实施例二，在所有基站完成一次广播之后，最后广播的基站再次进行广播，在此广播时隙中，最后广播的基站所广播出的信号的频率为其在第一时隙的频率估算值的M倍，相位为其在之前所有时隙的相位估算之和；而除最后广播的基站之外的其余所有基站均接收最后广播的基站所广播出的信号，并分别通过各自的频率估算单元估算各自在当前时隙内接收广播信号产生的频率估算值、通过相位估算单元估算各自在当前时隙内接收广播信号产生的相位估算值；As a second embodiment, after all the base stations complete a broadcast, the last broadcasted base station broadcasts again. In this broadcast time slot, the frequency of the signal broadcast by the last broadcasted base station is its frequency estimate in the first time slot. M times, the phase is the sum of the phase estimates of all previous time slots; and all the base stations except the last broadcasted base station receive the signals broadcast by the last broadcasted base station and pass the respective frequency estimation units respectively. Estimating respective frequency estimation values generated by receiving broadcast signals in the current time slot, and estimating, by the phase estimation unit, phase estimation values respectively generated by receiving the broadcast signals in the current time slot;

在最后广播的基站完成再次广播之后，各个基站的同步单元通过如下方式确定各自同步后的载波频率和载波相位：对于同步后的载波频率，初级信号产生基站的同步单元将其自身载波频率值先后乘以M-1，得到其同步后的载波频率；除初级信号产生基站之外的其余基站的同步单元将各自在第一时隙的频率估算值先后乘以M-1，得到各自同步后的载波频率；对于同步后的载波相位，最后广播的基站的同步单元将除其自身广播的两个时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；除最后广播的基站之外的其余基站的同步单元，将各自在最后一个时隙的相位估算值减去在倒数第二个时隙的相位估算值，得到各自同步后的载波相位。 After the last broadcasted base station completes the rebroadcast, the synchronization unit of each base station determines the respective synchronized carrier frequency and carrier phase by: for the synchronized carrier frequency, the synchronization unit of the primary signal generating base station has its own carrier frequency value successively Multiply by M-1 to obtain the synchronized carrier frequency; the synchronization units of the remaining base stations except the primary signal generating base station multiply the frequency estimation values of the respective first time slots by M-1, respectively, to obtain the respective synchronized Carrier frequency; for the synchronized carrier phase, the synchronization unit of the last broadcast base station adds the phase estimation values of all the slots except the two slots broadcasted by itself to obtain the synchronized carrier phase; The synchronization units of the remaining base stations other than the broadcast base station subtract the phase estimation values of the last time slot from the phase estimation values of the last time slot to obtain the respective synchronized carrier phases.

本发明适用于无线通信技术领域，特别是涉及分布式时分双工***、多小区通信***、协作通信***、分布式adhoc/mesh网络等的载波同步。The present invention is applicable to the field of wireless communication technologies, and in particular, to carrier synchronization of a distributed time division duplex system, a multi-cell communication system, a cooperative communication system, a distributed adhoc/mesh network, and the like.

以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等，均应包含在本发明的保护范围之内。 The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

一种快速波束合成***的源端各发送天线的载波同步方法，其特征在于，所述分布式波束合成***包括源端和目的端，所述源端具有M个基站，所述M个基站中包括一初级信号产生基站；所述载波同步方法包括下述步骤：A carrier synchronization method for each transmitting antenna at a source end of a fast beamforming system, characterized in that the distributed beamforming system includes a source end and a destination end, and the source end has M base stations, and the M base stations A primary signal generating base station is included; the carrier synchronization method includes the following steps:

步骤A，初级信号产生基站在第一时隙广播所述初级信号；Step A, the primary signal generating base station broadcasts the primary signal in a first time slot;

步骤B，源端除该基站产生初级信号之外的其余所有基站均接收所述初级信号，并分别估算各自在第一时隙内接收初级信号产生的频率估算值和相位估算值；Step B: The source end receives all the base signals except the primary signal generated by the base station, and separately estimates frequency estimation values and phase estimation values respectively generated by receiving the primary signals in the first time slot;

步骤C，在之后的时隙中，其余所有基站顺次广播；在每次广播时，当前的广播基站所广播出的信号的频率为其在第一时隙的频率估算值，相位为其在前一时隙的相位估算值；而除当前的广播基站之外的其余所有基站均接收当前的广播基站所广播出的信号，并分别估算各自在当前时隙内接收广播信号而产生的相位估算值；Step C, in the subsequent time slots, all the other base stations broadcast in sequence; at each broadcast, the frequency of the signal broadcast by the current broadcast base station is its frequency estimate in the first time slot, and the phase is The phase estimation value of the previous time slot; and all the base stations except the current broadcast base station receive the signals broadcast by the current broadcast base station, and respectively estimate the phase estimation values respectively generated by receiving the broadcast signals in the current time slot. ;

步骤D，每个基站都完成广播之后，各个基站的同步后的载波频率和载波相位根据如下方式确定：Step D: After each base station completes broadcasting, the synchronized carrier frequency and carrier phase of each base station are determined as follows:

对于初级信号产生基站，将其自身载波频率值乘以M，得到其同步后的载波频率；将其自身载波相位值与其在除第一时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；For the primary signal generating base station, multiply its own carrier frequency value by M to obtain its synchronized carrier frequency; add its own carrier phase value to its phase estimate of all time slots except the first time slot, Obtaining the carrier phase after synchronization;

对于除初级信号产生基站之外的其余所有基站，将各自在第一时隙的频率估算值先后乘以M，得到各自同步后的载波频率；将各自的广播时隙的前一时隙的相位估算值乘以2之后与剩下时隙的相位估算值相加，得到各自同步后的载波相位。For all the base stations except the primary signal generating base station, the frequency estimation values of the respective first time slots are multiplied by M in order to obtain the respective synchronized carrier frequencies; the phase estimation of the previous time slot of the respective broadcast time slots is obtained. After multiplying the value by 2, the phase estimation values of the remaining time slots are added to obtain the carrier phases after the respective synchronization.
如权利要求1所述的载波同步方法，其特征在于，在步骤C和步骤D之间，所述方法还包括下述步骤C1：The carrier synchronization method according to claim 1, wherein between step C and step D, the method further comprises the following step C1:

步骤C1，在所有基站完成一次广播之后，最后广播的基站再次进行广播，在此广播时隙中，最后广播的基站所广播出的信号的频率为其在第一时隙的频率估算值的M倍，相位为其在之前所有时隙的相位估算之和；而除最后广播的基站之外的其余所有基站均接收最后广播的基站所广播出的信号，并分别估算各自在此时隙内接收广播信号而产生的相位估算值；Step C1, after all the base stations complete a broadcast, the last broadcasted base station broadcasts again. In the broadcast time slot, the frequency of the signal broadcast by the last broadcasted base station is its frequency in the first time slot. M times the estimated value, the phase is the sum of the phase estimates of all previous time slots; and all the base stations except the last broadcasted base station receive the signals broadcast by the last broadcasted base station, and estimate the respective a phase estimate generated by receiving a broadcast signal in this time slot;

此时，所述步骤D替换为下述步骤E：At this time, the step D is replaced by the following step E:

步骤E，在最后广播的基站完成再次广播之后，各个基站的同步后的载波频率和载波相位根据如下方式确定：Step E: After the last broadcasted base station completes the rebroadcast, the synchronized carrier frequency and carrier phase of each base station are determined as follows:

对于同步后的载波频率，初级信号产生基站将其自身载波频率值先后乘以M-1，得到其同步后的载波频率；除初级信号产生基站之外的其余基站将各自在第一时隙的频率估算值先后乘以M-1，得到各自同步后的载波频率；For the synchronized carrier frequency, the primary signal generating base station multiplies its own carrier frequency value by M-1 to obtain its synchronized carrier frequency; the remaining base stations except the primary signal generating base station will each be in the first time slot. The frequency estimation values are multiplied by M-1 to obtain the carrier frequencies after synchronization;

对于同步后的载波相位，最后广播的基站将除其自身广播的两个时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；除最后广播的基站之外的其余基站，将各自在最后一个时隙的相位估算值减去在倒数第二个时隙的相位估算值得到各自同步后的载波相位。For the synchronized carrier phase, the last broadcasted base station adds the phase estimation values of all the time slots except the two time slots broadcast by itself to obtain the synchronized carrier phase; except for the last broadcasted base station. The remaining base stations subtract the phase estimates of the last time slot from the phase estimates of the last time slot to obtain the respective synchronized carrier phases.
一种快速波束合成***，包括源端和目的端，所述源端具有M个基站，所述M个基站中包括一初级信号产生基站；其特征在于，每个基站均包括频率估算单元、相位估算单元和同步单元；A fast beamforming system includes a source end and a destination end, wherein the source end has M base stations, and the M base stations include a primary signal generating base station; wherein each base station includes a frequency estimating unit and a phase Estimating unit and synchronizing unit;

所述初级信号产生基站用于产生初级信号并在第一时隙广播所述初级信号，源端除该基站产生初级信号之外的其余所有基站均接收所述初级信号，并分别通过各自的频率估算单元估算各自在第一时隙内接收初级信号产生的频率估算值、通过相位估算单元估算各自在第一时隙内接收初级信号产生的相位估算值；The primary signal generating base station is configured to generate a primary signal and broadcast the primary signal in a first time slot, and all base stations other than the base station generating a primary signal at the source end receive the primary signal and respectively pass respective frequencies The estimating unit estimates respective frequency estimation values generated by receiving the primary signals in the first time slot, and estimating, by the phase estimating unit, phase estimation values respectively generated by receiving the primary signals in the first time slot;

在之后的时隙中，其余所有基站顺次广播；在每次广播时，当前的广播基站所广播出的信号的频率为其在第一时隙的频率估算值，相位为其在前一时隙的相位估算值；而除当前的广播基站之外的其余所有基站均接收当前的广播基站所广播出的信号，并分别通过各自的频率估算单元估算各自在当前时隙内接收广播信号产生的频率估算值、通过相位估算单元估算各自在当前时隙内接收广播信号产生的相位估算值； In the subsequent time slots, all other base stations broadcast in sequence; at each broadcast, the frequency of the signal broadcast by the current broadcast base station is its frequency estimate in the first time slot, and the phase is its previous time slot. The phase estimation value; and all the base stations except the current broadcast base station receive the signals broadcast by the current broadcast base station, and respectively estimate the frequencies generated by the respective broadcast signals in the current time slot by the respective frequency estimation units. Estimating a value, estimating, by the phase estimating unit, a phase estimation value generated by each receiving a broadcast signal in a current time slot;

每个基站都完成广播之后，各个基站的同步单元通过如下方式确定各自同步后的载波频率和载波相位：After each base station completes the broadcast, the synchronization units of the respective base stations determine the carrier frequencies and carrier phases after the respective synchronizations by:

对于初级信号产生基站，其同步单元用于将其自身载波频率值先后乘以M，得到其同步后的载波频率；其同步单元用于将其自身载波相位值与其在除第一时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；For the primary signal generating base station, its synchronization unit is used to multiply its own carrier frequency value by M to obtain its synchronized carrier frequency; its synchronization unit is used to divide its own carrier phase value with its other than the first time slot. The phase estimation values of all the time slots are added to obtain the carrier phase after synchronization;

对于除初级信号产生基站之外的其余所有基站，其同步单元用于将各自在第一时隙的频率估算值先后乘以M，得到各自同步后的载波频率；其同步单元用于将各自的广播时隙的前一时隙的相位估算值乘以2之后与剩下时隙的相位估算值相加，得到各自同步后的载波相位。For all base stations except the primary signal generating base station, the synchronization unit is configured to multiply the respective frequency estimation values in the first time slot by M to obtain the respective synchronized carrier frequencies; the synchronization unit is used to The phase estimation value of the previous time slot of the broadcast time slot is multiplied by 2 and added to the phase estimation value of the remaining time slot to obtain the carrier phase after the respective synchronization.
如权利要求3所述的快速波束合成***，其特征在于，在所有基站完成一次广播之后，最后广播的基站再次进行广播，在此广播时隙中，最后广播的基站所广播出的信号的频率为其在第一时隙的频率估算值的M倍，相位为其在之前所有时隙的相位估算之和；而除最后广播的基站之外的其余所有基站均接收最后广播的基站所广播出的信号，并分别通过各自的频率估算单元估算各自在当前时隙内接收广播信号产生的频率估算值、通过相位估算单元估算各自在当前时隙内接收广播信号产生的相位估算值；The fast beamforming system according to claim 3, wherein after all the base stations complete a broadcast, the last broadcasted base station broadcasts again, in the broadcast time slot, the frequency of the signal broadcast by the last broadcasted base station For the M times of the frequency estimate of the first time slot, the phase is the sum of the phase estimates of all previous time slots; and all the base stations except the last broadcasted base station are broadcasted by the base station receiving the last broadcast. And estimating, by respective frequency estimating units, frequency estimation values respectively generated by receiving the broadcast signals in the current time slot, and estimating, by the phase estimating unit, phase estimation values respectively generated by receiving the broadcast signals in the current time slot;

在最后广播的基站完成再次广播之后，各个基站的同步单元通过如下方式确定各自同步后的载波频率和载波相位：After the last broadcasted base station completes the rebroadcast, the synchronization units of the respective base stations determine the respective synchronized carrier frequencies and carrier phases by:

对于同步后的载波频率，初级信号产生基站的同步单元将其自身载波频率值先后乘以M-1，得到其同步后的载波频率；除初级信号产生基站之外的其余基站的同步单元将各自在第一时隙的频率估算值先后乘以M-1，得到各自同步后的载波频率；For the synchronized carrier frequency, the synchronization unit of the primary signal generating base station multiplies its own carrier frequency value by M-1 to obtain the synchronized carrier frequency; the synchronization units of the remaining base stations except the primary signal generating base station will respectively The frequency estimation values in the first time slot are multiplied by M-1 to obtain the carrier frequencies after synchronization;

对于同步后的载波相位，最后广播的基站的同步单元将除其自身广播的两个时隙之外的所有时隙的相位估算值相加，得到其同步后的载波相位；除最后广播的基站之外的其余基站的同步单元，将各自在最后一个时隙的相位估算值减去在倒数第二个时隙的相位估算值，得到各自同步后的载波相位。 For the synchronized carrier phase, the synchronization unit of the last broadcast base station adds the phase estimation values of all the slots except the two slots broadcasted by itself to obtain the synchronized carrier phase; The synchronization units of the remaining base stations are subtracted from the phase estimation values of the last time slot by the phase estimation values of the last time slot to obtain the respective synchronized carrier phases.