WO2003036839A1 - Procede de traitement de signal multi-trajet et dispositif utilisant une recherche de trajet lente et une estimation de canal rapide multi-fenetre - Google Patents

Procede de traitement de signal multi-trajet et dispositif utilisant une recherche de trajet lente et une estimation de canal rapide multi-fenetre Download PDF

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Publication number
WO2003036839A1
WO2003036839A1 PCT/CN2002/000740 CN0200740W WO03036839A1 WO 2003036839 A1 WO2003036839 A1 WO 2003036839A1 CN 0200740 W CN0200740 W CN 0200740W WO 03036839 A1 WO03036839 A1 WO 03036839A1
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Prior art keywords
window
fast
path
estimation
multipath
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PCT/CN2002/000740
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English (en)
French (fr)
Inventor
Chunming Zhao
Ling Wang
Liangcheng Jiang
He Huang
Shixin Cheng
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The Research Institute Of Telecommunication Transmission, Mii
Southeast University
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Publication of WO2003036839A1 publication Critical patent/WO2003036839A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/707—Spread spectrum techniques using direct sequence modulation
    • H04B1/709—Correlator structure
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J13/00—Code division multiplex systems
    • H04J13/0007—Code type
    • H04J13/0022—PN, e.g. Kronecker

Definitions

  • the invention relates to the field of CDMA (Code Division Multiple Access) cellular mobile communication, in particular to a multipath signal processing method and device for slow path search and multi-window fast channel estimation in a CDMA mobile communication system.
  • CDMA Code Division Multiple Access
  • Multipath fading in mobile communication systems can cause severe multipath interference in the system.
  • CDMA Code Division Multiple Access
  • the amplitude and phase of a multipath signal are estimated by receiving a pilot signal containing deterministic information, thereby making the multipath signal Time-domain diversity and coherent reception are possible.
  • This type of coherent spread-spectrum receiver that performs time-domain diversity processing on multipath fading signals is called a RAKE coherent receiver.
  • the pilot signal in a CDMA system is used to transmit known signals. It can not only extract the signal carrier and system timing, but also perform channel parameter estimation.
  • the purpose of channel parameter estimation is based on the received signal and the determined pilot sequence.
  • the channel fading factor c n is estimated. Assuming that the mobile channel is a frequency selective slow fading channel, c ,, can be considered to be approximately constant within a channel estimation interval.
  • the estimated formula is as follows ⁇
  • Y (t) is the equivalent baseband received signal
  • s. (t) is ascertained pilot signals
  • N a, ⁇ ⁇ , ⁇ ⁇ are multipath interference correlation properties of the spreading code is not ideal due to output multiple access interference and white noise generated by the correlation
  • T e is the time width of one chip
  • NT ⁇ is the channel estimation interval; it is the energy of one chip.
  • the implementation of a conventional RAKE receiver is completed by the following steps: First, search for a strong path in the entire energy distribution range of the multipath signal, and then track each strong path signal, and then perform spread spectrum reception and multipath combining on this basis. Although the calculation amount of this method is small, due to the There is a large range of random changes in degree and phase, which results in frequent path switching, which affects the performance of the RAKE receiver to a large extent.
  • an invention patent proposes a multi-path signal energy distribution window (referred to as a multi-path energy window) is defined as the effective distribution range of the signal fading factor c n .
  • the window width is extended by the delay range of the multi-path channel OK. Under different multipath fading environments (urban, rural, mountain), the widths are 3 microseconds, 6 microseconds, and 15 microseconds respectively. Due to the uncertainty of multipath signals, the width of the multipath energy window should be Take the maximum possible value (usually 30 microseconds), that is, two protection windows with a width of ⁇ chip should be added on both sides of the main window to ensure that multipath signals are not lost. Generally, the width of the main window is about 15 The microsecond, the guard window width is about 7 microseconds. This main window is also called the fast channel estimation window.
  • the present invention divides the multipath energy window into a fast estimation window and a
  • the rear protection window as shown in Figure 1, has the following main parameters: front and rear protection windows: 7 microseconds in width, set as chips; quick estimation window: 15 microseconds in width, set as L chips .
  • the fast channel estimation is performed in the fast estimation window, and the slow path search is performed in the protection window.
  • the multipath signal processing method combining the slow path search and fast channel estimation established by the present invention not only solves the problem of uncertain multipath signals, makes the processing robust, but also overcomes the problem of "based on multipath channel energy
  • the method of the present invention is called" based on slow path search and fast channel Estimating Multipath Signal Processing Methods ".
  • the energy delay distribution of a multipath channel has the following rules:
  • the emergence of strong paths is grouped, and generally includes more than two groups.
  • the present invention introduces the concept of a fast estimation sub-window.
  • the fast channel estimation window is divided into multiple sub-windows, and the interval between them is called a guard window.
  • the multi-path energy window includes multiple fast channel estimation sub-windows.
  • protection window as shown in Figure 2, the main parameters are described below.
  • the maximum number of sub-windows is quickly estimated, and the width of each window is I chips. I can be selected as 2, 4, 8, or more.
  • a multi-path signal processing method combining slow path search and fast channel estimation is still used.
  • Such processing not only maintains the advantages of the above-mentioned "fast estimation window + front and rear protection window” method, but also further reduces the amount of calculation. Therefore, the present invention is exactly called “multipath signal processing method based on slow path search and multi-window fast channel estimation”. Summary of the Invention It is an object of the present invention to provide a multipath signal processing method for slow path search and multi-window fast channel estimation. This method greatly reduces the amount of calculation while processing the entire multipath energy window.
  • Another object of the present invention is to provide a multi-path signal processing device for slow path search and multi-window fast channel estimation.
  • the device greatly reduces the amount of calculation while processing the entire multi-path energy window.
  • a multi-path signal processing method for slow path search and multi-window fast channel estimation includes the steps of: dividing a multi-path energy window into a fast estimation window and a protection window; Channel estimation; while performing fast channel estimation in the fast estimation window, perform slow new path search in the protection window.
  • a multipath signal processing device S for slow path search and multi-window fast channel estimation includes: a tapped delay line for delaying storage of a baseband received signal; a slow path searcher, It is used to obtain a signal with an interval of 1/2 chip from the baseband sampled signal received from the tapped delay line.
  • the fast channel estimator is used to estimate the multipath channel in multiple fast estimation sub-windows in a multipath energy window.
  • Multi-path energy window center-of-gravity calculation / loop filter which is used to perform multi-path energy window center-of-gravity calculation and loop filtering processing on the channel estimation value output from the fast channel estimator; a local PN code phase adjustment amount generator for Judge the result of the calculation of the center of gravity of the multipath energy window / the processing of the loop filter to obtain the phase adjustment amount of the PN code and send it to the PN code generator; a strong path selector for outputting from the fast channel estimator Compare the intensity of the channel estimation values of the two, select the J strongest paths from them, and send their positions and their corresponding channel estimation values to the Rake correlator and Rake combiner, respectively.
  • PN code generator used to be controlled by the multi-path energy window center of gravity calculation I-loop filter, local PN code phase adjustment amount generator, and slow path searcher, used to fine-tune the PN code phase to make the center of gravity of the main window Adjust to the target value.
  • the multipath channel estimator of the CDMA system constituted by the present invention has superior performance and can reduce the complexity of calculation.
  • FIG. 1 is a schematic diagram of a multi-path energy window division method
  • 2 is a schematic diagram of dividing a multipath energy window according to the method of the present invention
  • FIG. 3 is a block diagram of a multipath signal processing apparatus for slow path search and multi-window fast channel estimation according to an embodiment of the present invention. detailed description
  • the method flow of the present invention is as follows:
  • the required effective multipath channel is estimated, and its amplitude value is judged.
  • the initial effective paths can be obtained. These initial effective paths must meet the following conditions: First, the signal strength of the initial effective path is greater than a certain decision threshold. (The threshold of this decision should be greater than the sidelobe value associated with the PN code part.) Second, the interval between every two initial effective paths should be greater than the width occupied by the fast estimation window. Let the number of initial effective paths searched be M, so that M fast estimation sub-windows are determined.
  • multi-window fast channel estimation is performed: using high multi-path resolution estimation, the centers of the M fast estimation sub-windows are aligned with these initial effective path positions, respectively.
  • a single fast channel estimator is used to calculate the channel estimation value of each path in a time-division multiplexed manner; or for all fast estimation (sub) windows, the same fast channel estimator is reused.
  • the channel estimator performs fast channel estimation on the multipath channels in these sub-windows. It can track the frequently changing multipath signals in the window in time. Its update rate is about 9,000 times per second, and it can adapt to the equivalent vehicle speed of 500km I h. Channel estimation in a mobile environment.
  • a slow new path search is performed in the protection window, that is, the slow path searcher searches for a new arrival path within the range of the multi-path energy window outside these fast estimation windows.
  • the weakest signal fast estimation sub-window is removed, the weakest fast estimation sub-window is forcibly adjusted, and the new fast estimation sub-window is used to cover the new path.
  • the structure of the multipath signal processing device of the slow path search and multi-window fast channel estimation of the present invention is shown in FIG. 3.
  • the device includes a slow path searcher, a tapped delay line, a multi-window fast channel estimator, and a multi-path energy window.
  • the center of gravity calculation consists of I loop filtering, I local PN code phase adjuster, strong path selector and PN code generator. The specific functions of each part are explained below.
  • Slow path searcher This section obtains the signal with the interval of 1/2 chips from the baseband sampling signal received by the tapped delay line. Perform a slow path search within the range of the multipath energy window (except the assigned fast estimation window) to obtain the initial effective path or the newly arrived effective path position.
  • the slow path search first performs channel estimation on different paths (see
  • a fast PN code generator can be used And time-division multiplexed correlators.
  • the intensity of each path is then compared with a threshold value to determine whether it is a valid arrival path signal.
  • the judgment shutter limit should be greater than the sidelobe value associated with the PN code part.
  • the first M strongest paths are selected as the initial effective paths from these signals, and the interval of each initial effective path should be greater than the width of the estimation window.
  • each effective arrival path is regarded as a new effective arrival path. If the strength of the new effective arrival path is greater than the multipath intensity in a certain fast estimation sub-window, a fast estimation sub-window switching process is performed.
  • Tap delay line This section stores the delay of the baseband received signal.
  • the delay interval is 1 / K chips, and K is a power of 2.
  • the length of the delay line covers a multipath energy window with a width of (L + 2A) chip interval.
  • the delay line is drawn out every 1/2 chips, a total of K (L + 2A) / 2 taps, and sent to the slow path searcher.
  • Fast channel estimator In the entire multipath energy window, it contains at most M fast channel estimation windows. If the width of each fast estimation window is I chip, a total of MXIXK delay line taps are required. In order to achieve the purpose of saving hardware resources, a multi-path channel in multiple fast estimation sub-windows may be estimated in a time division multiplexing manner. Multiple channel estimators can also be used to estimate multiple sub-windows at the same time to obtain a faster refresh rate of channel estimates.
  • the adjustment of the fast estimation sub-window position is determined by the center of gravity of the multipath energy window and the position of the new effective arrival path obtained by the slow path searcher.
  • the patent "pilot signal tracking method based on the multi-path channel center-of-gravity tracking loop" (patent number 00128222.0) is used to adjust the position of the multi-path energy window;
  • the weakest fast estimation sub-window needs to be removed, a new fast estimation sub-window is added to cover the new path, and the multi-path energy window center of gravity method is still used to refine the position of the window. Adjustment.
  • Multi-path energy window centroid calculation / loop filtering / local PN code phase adjustment amount generator This part first performs multi-path energy window centroid calculation and loop filtering processing on the channel estimation value output from the fast channel estimator, and then processes As a result, a decision is made to obtain a phase adjustment amount of the PN code and send it to the PN code generator.
  • Strong path selector This section compares the strength of the channel estimation value output from the fast channel estimator, selects the J strongest paths from it, and sends their positions and their corresponding channel estimation values to the Rake correlator and Rake, respectively. Combiner.
  • PN code generator This part is controlled by multi-path energy window centroid calculation I loop filtering I local PN code phase adjustment amount generator and slow path searcher, multi-path energy window centroid calculation I loop filtering I local PN code The phase adjuster is used to fine-tune the phase of the PN code so that the center of gravity of the main window is adjusted to the target value.
  • the low-speed path search completes the estimation of low multipath resolution, and the fast channel estimation uses high multipath resolution estimation.
  • the concept of fast estimation sub-window is introduced on the basis of fast estimation window, which further reduces the calculation amount.
  • the following takes a 3GPP WCDMA system as an example to illustrate the reduction of the channel estimation calculation amount of the present invention. Because the chip rate of the WCDMA system is 3.84 Mbps, if the multipath energy window width is set to 30 ⁇ ⁇ , the window length is about 116 chips. For the present invention, the number of sub-windows for fast channel estimation is 2, and the window width is Both are 2 ⁇ 5 (about 8 chips).
  • the update rate of the fast channel estimate be 19200 times per second and the multipath resolution be 0.25 chips.
  • the estimated update rate of the slow channel is 1000 times per second, and the multipath resolution is 0.5 chips.
  • the computational complexity is expressed as the number of paths to be estimated per second.
  • the method of the present invention requires fast channel estimation in two fast estimation sub-windows and slow channel estimation in a protection window.
  • the calculation complexity is:
  • the present invention can reduce the computational complexity to a large extent, and the price to be paid is that the difficulty of controlling multiple sub-windows is increased to a certain extent.

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  • Computer Networks & Wireless Communication (AREA)
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Description

慢速径搜索和多窗口快速信道估计的多径信号处理方法和装置 技术领域
本发明涉及 CDMA (码分多址） 蜂窝移动通信领域， 特别是 CDMA移动通信系 统中的慢速径搜索和多窗口快速信道估计的多径信号处理方法和装置。 背景技术
移动通信系统存在的多径衰落现象会造成系统严重的多径干扰。 在使用扩频技 术的 CDMA (码分多址）蜂窝移动通信系统中， 通过接收含有确知信息的导频（Pilot) 信号， 对多径信号的幅度和相位进行估计， 从而使多径信号的时域分集和相干接收 成为可能。 这种针对多径衰落信号进行时域分集处理的相干扩频接收机称为 RAKE 相干接收机。
为获得较好的 RAKE接收性能， 除了必须实现本地扩频序列 （PN码） 与接收信 号的同步以外， 还必须找到足够强和足够多的多径信号， 并需估计出各强径的信道 衰落因子 （即信道估计）， 才能进行对多个含相同信息且衰落特性互相独立的各个单 径信号进行相位校正和最大比合并处理， 从而达到提高信号干扰比的目的。
CDMA 系统中的导频信号用来传送已知信号， 利用它不但可以提取出信号载波 和系统定时， 还可以进行信道参数估计等， 信道参数估计的目的在于根据接收信号 和确知的导频序列估计出信道衰落因子 cn。 假设移动信道是频率选择性慢衰落信道， 则可认为在一个信道估计区间内 c,,近似为常数。 估计的公式如下-
cn = -^— f c r(t - nTc ) - s0' (t)dt = cn + Na + Nc + N2 (公式 1 )
式中， Y(t)是等效基带接收信号， s。(t)是确知的导频信号， Na、 Νε、 Νζ分别是扩频码 的相关特性不够理想造成的多径干扰， 多址干扰以及白噪声通过相关器后产生的输 出； Te是一个码片的时间宽度， ΝΤε是信道估计区间； 是一个码片的能量。
传统的 RAKE接收机的实现方法由以下步骤完成： 首先在整个多径信号能量分 布范围内对强径搜索， 再对每条强径信号进行跟踪， 在此基础进行扩频接收与多径 合并。 这种方法的计算量虽然较小， 但是由于实际移动环境下每一径到达信号在幅 度和相位上均有较大范围的随机变化， 从而导致频繁的径切换， 从而在较大程度上 影响 RAKE接收机的性能。
针对上述情形， 发明专利（专利号为 00128222.0提出多径信号能量分布窗口 （简 称为多径能量窗） 定义为信号衰落因子 cn的有效分布范围。 该窗口宽度由多径信道 的时延扩展范围确定。 在不同的多径衰落环境 （城市、 乡村、 山区） 下， 宽度分别 为 3 微秒、 6微秒、 15 微秒。 由于多径信号出现的不确定性。 多径能量窗的宽度应 取最大可能值 （通常为 30 微秒）， 即在主窗两侧还应加上宽度为 Δ码片的两个保护 窗， 才能保证不会丢失多径信号。 通常， 主窗宽度约为 15 微秒， 保护窗宽度约为 7 微秒。 该主窗又称快速信道估计窗。
由于在整个多径能量窗范围内进行快速信道估计所需的计算量较大， 本发明在 上述快速信道估计窗和保护窗概念的基础上， 将多径能量窗划分为快速估计窗和前、 后保护窗， 如图 1 所示， 其主要参数如下， 前、 后保护窗： 宽度分别为 7微秒， 设 为 个码片； 快速估计窗： 宽度为 15微秒， 设为 L个码片。 在快速估计窗内进行快 速信道估计， 同时在保护窗内进行慢速径搜索。 本发明建立的慢速径搜索和快速信 道估计相结合的多径信号处理方法不但解决了多径信号出现不确定的问题， 使处理 具有稳健性， 同时还克服了题目为 "基于多径信道能量窗重心跟踪环路的导频信道 跟踪方法" 的专利申请中信道估计器运算量较大和传统方法在径切换频繁时性能下 降的缺点， 故本发明方法称为 "基于慢速径搜索和快速信道估计的多径信号处理方 法"。
在移动通信环境下多径信道的能量延迟分布具有如下规律： 强径的出现是成组 的， 一般包括两组以上。 本发明针对这一规律又引入了快速估计子窗的概念， 将快 速信道估计窗划分为多个子窗， 之间的间隔称为保护窗， 这样多径能量窗包括了多 个快速信道估计子窗和保护窗， 如图 2 所示， 主要参数描述如下。 快速估计子窗的 个数最多为 M个， 每个窗宽度为 I个码片， I可选为 2、 4、 8或更大。 对这些子窗和 保护窗的处理仍然采用慢速径搜索和快速信道估计相结合的多径信号处理方法。 这 样的处理不但保持了上述 "快速估计窗 +前后保护窗"方法的优点， 而且进一步减 少了运算量。 故本发明确切称为 "基于慢速径搜索和多窗口快速信道估计的多径信 号处理方法"。 发明内容 本发明的一个目的是提供一种慢速径搜索和多窗口快速信道估计的多径信号处 理方法， 该方法在处理整个多径能量窗的同时， 大大减少了计算量。
本发明的另一个目的是提供一种慢速径搜索和多窗口快速信道估计的多径信号 处理装置， 该装置在处理整个多径能量窗的同时， 大大减少了计算量。
根据本发明的一个方面， 一种慢速径搜索和多窗口快速信道估计的多径信号处 理方法， 包括步骤： 将多径能量窗划分为快速估计窗和保护窗； 在快速估计窗内进 行快速信道估计； 在快速估计窗内进行快速信道估计的同时在保护窗内进行慢速新 径搜索。
此外， 该方法包括： 在整个多径能量窗范围内进行初始慢速径搜索； 对接收信 号进行 1 I 2码片间隔采样；按： = -^— y(t - nTc ) - s0' (t)dt = cn + Na + Nc + N2 . 行相关处理， 得到所需的多径信道估计， 并对其幅度值进行判决； 通过慢速径搜索 获得初始有效值； 采用高多径分辨率估计将 M个快速估计子窗的中心分别对准这些 初始有效径位置； 在多径能量窗范围内对保护窗内所述快速估计窗以外的新的到达 径进行慢速新径搜索。
根据本发明的另一个方面， 一种慢速径搜索和多窗口快速信道估计的多径信号 处理装 S, 包括： 抽头延迟线， 用于对基带接收信号进行延迟存储； 慢速径搜索器， 用于从抽头延迟线接收的基带采样信号中获得间隔为 1 / 2码片的信号； 快速信道估 计器， 用于在多径能量窗内对多个快速估计子窗内的多径信道进行估计； 多径能量 窗重心计算 /环路滤波器， 用于对从快速信道估计器输出的信道估计值进行多径能量 窗重心计算及环路滤波处理； 本地 PN码相位调整量发生器， 用于对所述多径能量窗 重心计算 /环路滤波器处理结果进行判决， 获得 PN码相位调整量， 并将其送往 PN码 发生器； 强径选择器， 用于对从快速信道估计器输出的信道估计值强度进行比较， 从中选择出 J个最强径，将其位置及其相应的信道估计值分别送给 Rake相关器和 Rake 合并器； 和 PN码发生器， 用于受多径能量窗重心计算 I环路滤波器和本地 PN码相 位调整量发生器以及慢速径搜索器的控制， 用于微调 PN码相位， 使主窗重心调整到 目标值。
本发明有益效果： 本发明构成的 CDMA系统多径信道估计器性能优越， 能够降 低计算复杂难度。 附图说明
图 1是多径能量窗划分方法的示意图； 图 2是根据本发明的方法划分多径能量窗的示意图；
图 3 为根据本发明实施例的慢速径搜索和多窗口快速信道估计的多径信号处 理装置的方框图。 具体实施方式
本发明方法流程如下：
首先， 进行初始慢速径搜索： 初始慢速径搜索在整个多径能量窗范围内进行。 在对接收信号 1 I 2码片间隔采样后， 按： „ = -— f y(t - nTc) · s (t)dt = cn + Na + Nc + N2 进行相关处理， 得到所需的多径信道估计， 并对其幅度值进行判决。 通过慢速径搜 索， 可获得初始有效径。 这些初始有效径必须满足如下条件： 首先， 该初始有效径 的信号强度大于某一判决门限 （此判决门限应大于 PN码部分相关的旁瓣值）； 其次， 每两个初始有效径的间隔应大于快速估计窗所占据的宽度。 设搜索出的初始有效径 数为 M， 由此可确定出 M个快速估计子窗。
此后， 执行多窗口快速信道估计： 采用高多径分辨率的估计， 将 M个快速估计 子窗的中心分别对准这些初始有效径位置。 在每个快速估计 （子） 窗内采用单个快 速信道估计器以时分复用的方式计算每条径的信道估计值； 或者对所有快速估计 (子） 窗， 复用同一快速信道估计器， 快速信道估计器对这些子窗内的多径信道进 行快速信道估计， 能及时跟踪窗口内频繁变化的多径信号， 其更新速率约为每秒钟 9000次， 可适应等效车速为 500km I h的移动环境下的信道估计。
在进行多窗口快速信道估计的同时， 在保护窗内进行慢速新径搜索， 也即慢速 径搜索器在去除这些快速估计窗以外的多径能量窗范围内进行新的到达径的搜索。 一旦检测到新的有效到达径， 则去除信号最弱快速估计子窗， 强制调整强度最弱的 快速估计子窗， 并用新的快速估计子窗覆盖该新径。
本发明的慢速径搜索和多窗口快速信道估计的多径信号处理装置结构如图 3 所 示， 该装置由慢速径搜索器、 抽头延迟线、 多窗口快速信道估计器、 多径能量窗重 心计算 I环路滤波 I本地 PN码相位调整器、 强径选择器和 PN码发生器等部分组成。 各部分的具体功能说明如下。 慢速径搜索器： 该部分从抽头延迟线接收的基带采样信号中获得间隔为 1 /2码 片的信号。 在多径能量窗范围内 （已分配的快速估计窗除外） 进行慢速径搜索， 以 获得初始有效径或新到达有效径的位置， 慢速径搜索首先对不同径进行信道估计 （参 见
cn +Na +Nc +Nz), 具体可采用快速 PN码发生器
Figure imgf000007_0001
和时分复用的相关器组实现。 然后将每一径的强度与一个门限值进行比较， 从而决 定是否为有效到达径信号。判快门限应大于 PN码部分相关的旁瓣值， 在初始化阶段， 从这些到达径信号中选取前 M 个最强径作为初始有效径， 各个初始有效径的间隔应 大于估计窗的宽度。 初始化完成后， 每个有效的到达径视为新的有效到达径， 若新 的有效到达径的强度大于某一个快速估计子窗内的多径强度， 则进行快速估计子窗 切换处理。
抽头延迟线： 该部分对基带接收信号进行延迟存储， 延迟间隔为 1 /K码片， K 取 2 的幂次。 延迟线的长度覆盖宽度为 （L+2A) 码片间隔的多径能量窗。 将延迟 线每隔 1 /2码片引出一个抽头， 共 K (L+2A) /2个抽头， 送入慢速径搜索器。
快速信道估计器： 在整个多径能量窗内， 最多包含 M 个快速信道估计窗。 若每 个快速估计窗的宽度为 I码片， 则共需 MXIXK个延迟线抽头。 为达到节省硬件资 源的目的， 可采用时分复用的方式对多个快速估计子窗内的多径信道进行估计。 也 可采用多个信道估计器对多个子窗同时进行估计， 以获得更快的信道估计值的刷新 速度。 信道估计的公式 =— !- γ(ί -nTc)- s0'(t)dt = cn +Na +Ne +Nz。 快速估计 子窗位置的调整由多径能量窗重心和慢速径搜索器所获得的新有效到达径的位置共 同来决定。 当径变化未跳出快速估计子窗时， 采用专利 "基于多径信道重心跟踪环 路的导频信号跟踪方法"（专利号为 00128222.0) 对多径能量窗的位置进行调整； 当 新有效径的位置处于保护窗内时， 则需去除强度最弱的快速估计子窗， 增加一个新 的快速估计子窗， 使之覆盖该新径， 之后仍采用多径能量窗重心方法对窗口的位置 进行精细调整。
多径能量窗重心计算 /环路滤波 /本地 PN 码相位调整量发生器： 该部分首先 对从快速信道估计器输出的信道估计值进行多径能量窗重心计算及环路滤波处理， 再对处理结果进行判决， 获得 PN码相位调整量， 并将其送往 PN码发生器。
强径选择器： 该部分对从快速信道估计器输出的信道估计值强度进行比较， 从 中选择出 J个最强径， 将其位置及其相应的信道估计值分别送给 Rake相关器和 Rake 合并器。
PN码发生器： 该部分受多径能量窗重心计算 I环路滤波 I本地 PN码相位调整 量发生器和慢速径搜索器的控制， 多径能量窗重心计算 I环路滤波 I本地 PN码相位 调整器用于微调 PN码相位， 使主窗重心调整到目标值。
本发明的优点主要体现在以下几个方面：
1. 慢速径搜索完成低多径分辨率估计， 快速信道估计采用高多径分辨率估计。
2. 釆用慢速径搜索和快速信道估计结合的方法， 在处理整个多径能量窗的同 时， 大大减少了计算量。
3. 引入快速估计窗和保护窗的概念， 解决了传统方法中径频繁切换时 RAKE 接收性能下降的问题。
4. 在快速估计窗的基础上引入快速估计子窗的概念， 进一步减少了计算量。 下面以 3GPP WCDMA系统为例， 说明本发明在信道估计计算量方面的减少。 因 WCDMA系统的码片速率为 3.84Mbps， 若多径能量窗宽度设定为 30μδ， 则 窗口长度约为 116个码片， 对于本发明可取快速信道估计子窗个数为 2， 其窗口宽度 均为 2μ5 (约 8个码片）。
设快速信道估计的更新速率为每秒 19200次， 多径分辨率为 0.25码片。 慢速信 道估计的更新速率为每秒 1000次， 多径分辨率为 0.5码片。 计算复杂度用每秒需估 计的径数表示。
本发明方法要求在两个快速估计子窗内进行快速信道估计， 在保护窗内进行慢 速信道估计， 计算复杂度为：
( 8 + 8 ) / 0.25 X 19.2k+ ( 116—8— 8) / 0.5 X lk= 1428800
可见本发明能够在较大程度上降低计算复杂度， 所需付出的代价是在一定程度上增 加了多子窗的控制方面的难度。
至此已结合本发明的优选实施例对本发明进行了详细说明， 本领域技术人员在 不脱离所附权利要求的范围和精神实质的情况下可以做出各种改进和变化。

Claims

权 利 要 求
1. 一种慢速径搜索和多窗口快速信道估计的多径信号处理方法， 包括步骤： 将多径能量窗划分为快速估计窗和保护窗；
在快速估计窗内进行快速信道估计；
在快速估计窗内进行快速信道估计的同时在保护窗内进行慢速新径搜索。
2. 根据权利要求 1所述的慢速径搜索和多窗口快速信道估计的多径信号处理方 法， 其中划分多径能量窗包括划分快速估计窗和在所述快速估计窗前和后的保护窗。
3. 根据权利要求 1所述的慢速径搜索和多窗口快速信道估计的多径信号处理方 法， 其中进一步包括将快速估计窗划分为多个子窗， 所述快速估计窗之间的间隔构 成保护窗。
4. 根据权利要求 1至 3中的任何一项所述的慢速径搜索和多窗口快速信道估计 的多径信号处理方法， 进一步包括步骤：
在整个多径能量窗范围内进行初始慢速径搜索；
对接收信号进行 1 I 2码片间隔采样； 按： c„ =—！— " γ{ί - nTc ) - sA' t)dt = cn + N + N + N,
NEC * " 进行相关处理， 得到所需的多径信道估计， 并对其幅度值进行判决；
通过慢速径搜索获得初始有效值；
采用高多径分辨率估计将 M个快速估计子窗的中心分别对准这些初始有效径位 置；
在多径能量窗范围内对保护窗内所述快速估计窗以外的新的到达径进行慢速新 径搜索。
5. 根据权利要求 4所述的慢速径搜索和多窗口快速信道估计的多径信号处理方 法， 其中进一步包括当在保护窗内出现新的有效到达径时， 强制调整强度最弱的快 速估计子窗覆盖该强径的步骤。
6. 根据权利要求 4所述的慢速径搜索和多窗口快速信道估计的多径信号处理方 法， 其中在快速估计子窗进行快速信道估计， 从而能够及时地跟踪窗口内频繁变化 的多径信号。
7. 根据权利要求 4所述的慢速径搜索和多窗口快速信道估计的多径信号处理方 法， 其中每个快速估计子窗内采用单个快速信道估计器以时分复用的方式计算每条 径的信道估计值， 或者对所有快速估计子窗复用同一快速信道估计器。
8. 一种慢速径搜索和多窗口快速信道估计的多径信号处理装置， 包括： 抽头延迟线， 用于对基带接收信号进行延迟存储；
慢速径搜索器， 用于从抽头延迟线接收的基带采样信号中获得间隔为 1 / 2码片 的信号；
快速信道估计器， 用于在多径能量窗内对多个快速估计子窗内的多径信道进行 估计；
多径能量窗重心计算 /环路滤波器， 用于对从快速信道估计器输出的信道估计值 进行多径能量窗重心计算及环路滤波处理；
本地 PN码相位调整量发生器， 用于对所述多径能量窗重心计算 /环路滤波器处 理结果进行判决， 获得 PN码相位调整量， 并将其送往 PN码发生器；
强径选择器， 用于对从快速信道估计器输出的信道估计值强度进行比较， 从中 选择出 J个最强径， 将其位置及其相应的信道估计值分别送给瑞克 （Rake) 相关器 和瑞克合并器； 和
PN码发生器， 用于受多径能量窗重心计算 I环路滤波器和本地 PN码相位调整 量发生器以及慢速径搜索器的控制， 用于微调 PN码相位， 使主窗重心调整到目标值。
9. 根据权利要求 8所述的慢速径搜索和多窗口快速信道估计的多径信号处理装 置， 其中快速信道估计器采用时分复用的方式对多个快速估计子窗内的多径信道进 行估计， 或采用多个信道估计器对多个子窗同时进行估计， 以获得更快的信道估计 值的刷新速度。
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6163563A (en) * 1996-12-31 2000-12-19 Lucent Technologies Inc. Digital communication system for high-speed complex correlation
WO2001065789A1 (fr) * 2000-02-29 2001-09-07 Thales Procede et dispositif d'estimation d'un canal de propagation
CN1332541A (zh) * 2000-12-18 2002-01-23 信息产业部电信传输研究所 基于多径信道能量窗重心跟踪环路的导频信道跟踪方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6163563A (en) * 1996-12-31 2000-12-19 Lucent Technologies Inc. Digital communication system for high-speed complex correlation
WO2001065789A1 (fr) * 2000-02-29 2001-09-07 Thales Procede et dispositif d'estimation d'un canal de propagation
CN1332541A (zh) * 2000-12-18 2002-01-23 信息产业部电信传输研究所 基于多径信道能量窗重心跟踪环路的导频信道跟踪方法

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