WO2008098442A1

WO2008098442A1 - Control method and control means for rate and power of subchannel per space

Info

Publication number: WO2008098442A1
Application number: PCT/CN2007/003148
Authority: WO
Inventors: Yunhui Liu; Xiaolin Zhang
Original assignee: Beijing Lenovo Software Ltd.; Lenovo (Beijing) Limited
Priority date: 2007-02-09
Filing date: 2007-11-06
Publication date: 2008-08-21
Also published as: CN101242205A

Abstract

A control method and control means for rate and power of subchannel per space are disclosed. The method includes: the receiver determines selected modulation and coding mode for every space subchannel based on channel status information on receiver side; the receiver informs the transmitter about the selected modulation and coding mode in the form of index; the transmitter performs pre-coding based on the statistic value of channel status information and modulation and coding mode of subchannel. Because the present invention only feedbacks the index, and does not need to feedback channel status information in real time, bandwidth requirementof feedback information is reduced. And present invention uses statistic information of channel status information, such as mean, variance or related matrix parameter, to pre-code, therefore, sensitivity of the pre-coding system performance to channel status information error is reduced.

Description

每空间子信道的速率和功率控制方法及控制装置技术领域 Rate and power control method and control device for each spatial subchannel

本发明涉及多天线无线通信技术，特别是涉及一种每空间子信道的速率和功率控制方法及控制装置。背景技术 The present invention relates to a multi-antenna wireless communication technology, and more particularly to a rate and power control method and control apparatus for a spatial sub-channel. Background technique

在蜂窝通信***中，不同通信链路所经历的无线通信条件在不同时间、不同位置、不同频率都是时刻发生变化的，这种变化在移动台高速移动的情况下更为明显。另一方面，相对于无线通信条件的时刻变化， ***所能获得的频谱效率、 ***容量等都受到所采用的信号传输技术以及无线信道条件的制约，因此，为了获得最大化的***频谱效率与通信容量，出现了一种可以随无线信道条件的变化而自适应调整的信号传输技术，即称为无线链路自适应技术。这种技术根据时刻变化的无线信道条件，动态地分配无线资源、自动调整调制编码方式和调度方法、釆用鲁棒的发射信号处理方法，其目的是最大化***性能，包括提高频谱效率和 ***容量，降低***性能对无线信道变化的敏感性等。 In a cellular communication system, the wireless communication conditions experienced by different communication links change at different times, at different locations, and at different frequencies. This change is more pronounced in the case of high-speed movement of the mobile station. On the other hand, relative to the time variation of wireless communication conditions, the spectrum efficiency and system capacity that the system can obtain are constrained by the adopted signal transmission technology and wireless channel conditions. Therefore, in order to obtain the maximum system spectrum efficiency and Communication capacity, a signal transmission technique that can be adaptively adjusted with changes in wireless channel conditions, called wireless link adaptation technology. This technology dynamically allocates radio resources, automatically adjusts the modulation and coding scheme and scheduling method, and employs a robust transmit signal processing method according to changing wireless channel conditions, with the aim of maximizing system performance, including improving spectral efficiency and system. Capacity, reducing the sensitivity of system performance to changes in wireless channels.

现有的基于 MIM0 (多输入多输出***）的自适应发射机技术包括 AMC (自适应调制编码）、自适应发射功率分配、自适应波束形成、 pre-coding (发射预编码）等。目前，有一些出版的论文讨论了 AMC与 pre-coding级联设计的方法，但基本都是从理论分析的角度进行了***性能分析和设^。虽然这些工作具有很好的参考价值，但是，这些设计大多没有过多考虑实际***的实现问题，存在复杂度高、实际无法实现等问题，比如性能优化后得出的连续调制阶问题、发射机侧不可靠信道状态信息、以及大量的反馈信息导致频谱效率的下降等，故不能直接应用于实际***实现。 Existing adaptive transmitter technologies based on MIM0 (Multiple Input Multiple Output System) include AMC (Adaptation Modulation Coding), Adaptive Transmit Power Allocation, Adaptive Beamforming, pre-coding (Transmission Precoding) and so on. At present, there are some published papers discussing the method of AMC and pre-coding cascade design, but basically the system performance analysis and design from the perspective of theoretical analysis. Although these works have good reference value, most of these designs do not take into account the actual system implementation problems, and there are problems such as high complexity and practical inability to achieve, such as continuous modulation order problems after performance optimization, transmitters. The side unreliable channel state information and a large amount of feedback information lead to a decrease in spectral efficiency, etc., and thus cannot be directly applied to actual system implementation.

已有的 AMC与 pre- coding级联设计中， AMC的实现方式为：接收机估计并反馈信道状态信息（在频分双工（FDD) 模式下）或发射机估计反向信道获得信道状态信息（在时分双工（TDD) 模式下），然后发射机依据信道状态信息，为每个空间子信道选择调制编码方式。这种 AMC方式的优点是发射机可以与预编码联合优化，根据整个***容量状况全局协调。缺点是： a. 发射机一般不能获得准确的信道状态信息，特别是在 FDD模式，信道信息的错误严重降低了 AMC的性能； b. 在 FDD模式下，大量信道信息的实时反馈需要占用很高的带宽，反馈信息越多，带宽浪费越大，反而降低频谱效率。这是发射机使用信道状态信息进行发射机设计的一个主要障碍。 In the existing AMC and pre-coding cascade design, the implementation of AMC is: The receiver estimates and feeds back the channel state information (in Frequency Division Duplex (FDD) mode) or the transmitter estimates the reverse channel to obtain channel state information. (In Time Division Duplex (TDD) mode), the transmitter then selects the modulation and coding scheme for each spatial subchannel based on the channel state information. The advantage of this AMC approach is that the transmitter can be optimized in conjunction with precoding, coordinated globally based on overall system capacity. The disadvantages are: a. The transmitter generally cannot obtain accurate channel state information, especially in the FDD mode, the channel information error seriously reduces the performance of the AMC; b. In FDD mode, real-time feedback of a large amount of channel information needs to occupy a very high bandwidth. The more feedback information, the more bandwidth is wasted, and the spectrum efficiency is reduced. This is a major obstacle for transmitters to use channel state information for transmitter design.

因此，需要在考虑发射机信道状态信息的不可靠性和调制阶的离散性和有限性的基础上提出一种 AMC与 pre- coding级联设计，以便在实现复杂度、性能和可实现性上取得平衡和提高。发明内容 Therefore, it is necessary to propose an AMC and pre-coding cascade design based on the unreliability of the transmitter channel state information and the dispersion and finiteness of the modulation order, in order to achieve complexity, performance and realizability. Balance and improve. Summary of the invention

本发明的目的在于提供一种每空间子信道的速率和功率控制方法及控制装置，解决现有技术没有考虑发射机信道状态信息的不可靠性和调制阶的离散性，在实现复杂度、性能和可实现性上难以取得平衡和提高的技术问题。 The object of the present invention is to provide a rate and power control method and a control device for a subspace per space, which solves the problem that the prior art does not consider the unreliability of the transmitter channel state information and the dispersion of the modulation order, and achieves complexity and performance. And technical problems that are difficult to achieve balance and improve in achievability.

为了实现上述目的，本发明提供了一种每空间子信道的速率和功率控制方法，其中，包括如下步骤： In order to achieve the above object, the present invention provides a rate and power control method for a spatial subchannel, which includes the following steps:

步骤一，接收机根据接收机侧估计的信道状态信息，确定每个空间子信道的调制编码方式； Step 1: The receiver determines a modulation and coding mode of each spatial subchannel according to channel state information estimated by the receiver side;

步骤二，接收机将所选择的调制编码方式通知发射机； Step two, the receiver notifies the transmitter of the selected modulation and coding mode;

步骤三，发射机根据信道状态信息的统计值，以及各空间子信道的调制编码方式进行预编码。 Step 3: The transmitter performs precoding according to the statistical value of the channel state information and the modulation and coding mode of each spatial subchannel.

上述的方法，其中，所述步骤二包括： The above method, wherein the step two includes:

步骤 a，将记录有各种调制编码方式的调制编码表预先分别存储在接收机和发射机中； Step a, storing modulation coding tables recorded with various modulation and coding modes in the receiver and the transmitter, respectively;

步骤 b，接收机根据在所述调制编码表中不同空间子信道所选择的调制编码方式的位置来确定索引信息； Step b, the receiver determines the index information according to the location of the modulation and coding mode selected by the different spatial subchannels in the modulation and coding table;

步骤 c，接收机将所述索引信息通过反馈信道发送给发射机； Step c, the receiver sends the index information to the transmitter through a feedback channel;

步骤 d, 发射机根据所述索引信息在所述调制编码表中找到不同空间子信道所选择的调制编码方式，并确定使用的空间子信道数目9。 Step d: The transmitter finds a modulation and coding mode selected by different spatial subchannels in the modulation and coding table according to the index information, and determines the number of spatial subchannels used by 9.

上述的方法，其中，所述步骤一包括： The above method, wherein the step one comprises:

步骤 A, 接收机测量和估计每个空间子信道的信干噪比 /信噪比； Step A, the receiver measures and estimates the signal to interference and noise ratio/signal to noise ratio of each spatial subchannel;

步骤 B, 将每个空间子信道的信干噪比 /信噪比与设定的阈值进行比较，根据阈值对应的调制阶为每个空间子信道选择对应的调制编码方式。上述的方法，其中，所述统计值为信道状态信息的均值、方差和 /或相关矩阵参数。 Step B: Compare a signal to interference and noise ratio/signal-to-noise ratio of each spatial subchannel with a set threshold, and select a corresponding modulation and coding mode for each spatial subchannel according to a modulation order corresponding to the threshold. The above method, wherein the statistical value is a mean value, a variance, and/or a correlation matrix parameter of the channel state information.

上述的方法，其中，在所述步骤三中，如果是处于时分双工***的条件下，则通过如下方式确定所述统计值：发射机通过估计反向信道，利用在一个信道相干时间段或设定的时间窗内获得的反向信道估计来计算所述统计值。 The above method, wherein, in the step 3, if it is under the condition of a time division duplex system, the statistical value is determined by: the transmitter estimates the reverse channel, utilizes a channel coherent time period or The statistical value obtained by calculating the reverse channel estimate obtained within the set time window.

上述的方法，其中，在所述步骤三中，如果是处于频分双工***的条件下，则通过如下方式确定所述统计值：接收机利用在一个信道相干时间段或设定的时间窗内获得的信道状态信息来计算所述统计值，并通过反馈信道将所述统计值反馈给发射机。 The above method, wherein, in the step 3, if it is in the condition of a frequency division duplex system, the statistical value is determined by: the receiver utilizing a channel coherent time period or a set time window The channel state information obtained therein is used to calculate the statistical value, and the statistical value is fed back to the transmitter through a feedback channel.

为了实现本发明的目的，本发明还提供了一种每空间子信道的速率和功率控制装置，其中，包括：接收机，用于根据接收机侧估计的信道状态信息，确定每个空间子信道所选择的调制编码方式，并将所选择的调制编码方式通知发射机；发射机，用于根据信道状态信息的统计值和各空向子信道的调制编码方式进行预编码。 In order to achieve the object of the present invention, the present invention also provides a rate and power control apparatus for a spatial subchannel, comprising: a receiver, configured to determine each spatial subchannel according to channel state information estimated by the receiver side. Selecting a modulation coding mode, and notifying the transmitter of the selected modulation and coding mode; and the transmitter, configured to perform precoding according to the statistical value of the channel state information and the modulation and coding mode of each of the null subchannels.

上述的装置，其特征在于，所述发射机中进行预编码处理的部分包括信道参数的信道估计模块、奇异值分解模块和空间子信道功率分配模块 _:：所述信道参数的信道估计模块，用于使用所述信道状态信息的统计值来获得当前的信道状态信息矩阵；所述奇异值分解模块，用于对信道态信息矩阵进行奇异值分解，得到 q个活动空间子信道的增益，并进一步得到发射波束赋形向量；所述空间子信道功率分配模块，用于根据子信道所选择的调制编码方式和所述 q个活动子信道的增益来确定 q个活动子信道的发射功率分配。 The above device is characterized in that: the part of the transmitter performing precoding processing comprises a channel estimation module of a channel parameter, a singular value decomposition module and a spatial subchannel power allocation module _:: a channel estimation module for the channel parameter, Obtaining a current channel state information matrix by using the statistical value of the channel state information; the singular value decomposition module is configured to perform singular value decomposition on the channel state information matrix to obtain gains of q active spatial subchannels, and further Obtaining a transmit beamforming vector; the spatial subchannel power allocation module, configured to determine a transmit power allocation of the q active subchannels according to a modulation coding mode selected by the subchannel and a gain of the q active subchannels.

上述的装置，其中，所述接收机和所述发射机中都存储有调制编码表，所述调制编码表记录有各种调制编码方式，所述接收机根据在所述调制编码表中不同子信道所选择的调制编码方式的位置来确定索引信息，并将所述引信息通过反馈信道发送给所述发射机，所述发射机根据所述索引信息在所述调制编码表中找到不同子信道所选择的调制编码方式。 In the above apparatus, a modulation and coding table is stored in both the receiver and the transmitter, and the modulation and coding table records various modulation and coding modes, and the receiver is different according to the modulation coding table. Determining index information by selecting a location of a modulation coding mode selected by the channel, and transmitting the index information to the transmitter through a feedback channel, where the transmitter finds different subchannels in the modulation and coding table according to the index information The selected modulation coding method.

上述的装置，其中，所述统计值为信道状态信息的均值、方差和 /或相关矩阵参数。 The above apparatus, wherein the statistical value is a mean value, a variance, and/or a related matrix parameter of channel state information.

本发明的优点在于： The advantages of the invention are:

1 利用接收机侧获得的近似完美的信道状态信息，本发明的 AMC能够比较准确地反映快速的无线信道变化，获得较好的鲁棒性能；其次，由于反馈的只是 "索引"，不用实时反馈信道状态信息，降低了反馈信道的带宽需求。 1 Using the approximate perfect channel state information obtained at the receiver side, the AMC of the present invention can compare Accurately reflect fast wireless channel changes and obtain better robust performance. Secondly, since the feedback is only "index", the channel state information is not fed back in real time, which reduces the bandwidth requirement of the feedback channel.

2 ) 预编码不直接使用信道状态信息，而是使用信道状态信息的统计信息，如均值、方差和相关矩阵参数，降低预编码***的性能对信道状态信息误差的敏感性。 2) Precoding does not directly use channel state information, but uses statistical information of channel state information, such as mean, variance and correlation matrix parameters, to reduce the sensitivity of the performance of the precoding system to channel state information errors.

3 ) 本发明提供了一种复杂度、可实现性和性能都合理平衡的 AMC与 pre-coding级联设计结构。特别的，本发明大大降低了反馈信息量。附图说明 3) The present invention provides an AMC and pre-coding cascade design structure that is reasonably balanced in complexity, achievability, and performance. In particular, the present invention greatly reduces the amount of feedback information. DRAWINGS

图 1为本发明方法的步骤流程图； Figure 1 is a flow chart showing the steps of the method of the present invention;

图 2为本发明中接收机根据 SINR/SNR选择调制阶的流程图。 2 is a flow chart of a receiver selecting a modulation order according to SINR/SNR in the present invention.

图 3为本发明中为接收机的功能模块图。 Figure 3 is a functional block diagram of a receiver in the present invention.

图 4为本发明中发射机物理层信号处理结构的框图； 4 is a block diagram of a signal processing structure of a physical layer of a transmitter in the present invention;

图 5 为本发明中发射机根据调制编码信息进行自适应调制的流程图；图 6为本发明中预编码参数处理模块的功能框图； 5 is a flow chart of adaptive modulation of a transmitter according to modulation and coding information according to the present invention; FIG. 6 is a functional block diagram of a precoding parameter processing module according to the present invention;

图 7为本发明中获取波束赋形向量 w,〜w,的信号处理流程； 7 is a signal processing flow for acquiring beamforming vectors w, 〜w in the present invention;

图 8为本发明中发射功率分配处理流程图。具体实施方式 FIG. 8 is a flowchart of a transmission power allocation process in the present invention. detailed description

通常来说，接收机可以获得近似完美的信道状态信息，测量或估计的 In general, the receiver can obtain approximately perfect channel state information, measured or estimated.

SINR/SNR ( SINR: 信干噪比， SNR: 信噪比）也相当准确，而对发射机来讲，获得信道状态信息误差较大，特别是在快速变化的无线环境中，从而导致 AMC或发射预编码***的性能降低。所以，本发明在接收机侧利用准确的信道状态信息为每个空间子信道选择调制编码方式，能够比较准确地反映快速的无线信道变化，获得较好的鲁棒性能，最重要的是，接收机不必卖时向发射机反馈信道状态信息，降低了反馈信道的带宽需求。 SINR/SNR (SINR: Signal to Interference and Noise Ratio, SNR: Signal to Noise Ratio) is also quite accurate, and for the transmitter, the channel state information error is large, especially in a rapidly changing wireless environment, resulting in AMC or The performance of the transmit precoding system is reduced. Therefore, the present invention selects a modulation coding mode for each spatial subchannel by using accurate channel state information on the receiver side, can accurately reflect fast wireless channel variation, obtain better robust performance, and most importantly, receive The machine does not have to sell the channel state information to the transmitter when it is sold, which reduces the bandwidth requirement of the feedback channel.

图 1为本发明方法的步骤流程图，如图，本发明包括- 步骤 101，接收机根据接收机侧估计的信道状态信息，确定每个空间子信道所选择的调制编码方式； 1 is a flow chart of the steps of the method of the present invention. As shown in the figure, the present invention includes: Step 101: The receiver determines, according to channel state information estimated by the receiver side, a modulation and coding mode selected by each spatial subchannel;

步骤 102，接收机将所选择的调制编码方式以索引的方式通过反馈信道反馈给发射机； Step 102: The receiver feeds the selected modulation and coding mode by feedback channel feedback Give the transmitter

步骤 103, 发射机根据信道状态信息的统计值和调制编码方式进行预编码，确定各子信道的发射功率和发射加权向量。 Step 103: The transmitter performs precoding according to a statistical value of the channel state information and a modulation and coding manner, and determines a transmit power and a transmit weight vector of each subchannel.

图 1仅为概括性的步骤流程，本发明中，接收机是测量和估计每个空间子信道的 SINR/SNR, 然后根据每个空间子信道的 SINR/SNR和设定阈值从有限的星座图中选择一种作为此空间子信道的信号调制编码方式，然后接收机将索引信息通过反馈信道发送给发射机。发射机根据接收到的 MCI (调制编码信息，即 "索弓 | "), 为每个空间子信道选择相应的调制编码方式。发射与编码器再根据确定的 MCI，利用获得的 CSI确定每个空间子信道的发射功率和发射波束方向。 1 is only a general procedure flow. In the present invention, the receiver measures and estimates the SINR/SNR of each spatial subchannel, and then based on the SINR/SNR of each spatial subchannel and sets a threshold from a limited constellation. A signal modulation coding mode is selected as the spatial subchannel, and then the receiver transmits the index information to the transmitter through the feedback channel. The transmitter selects the corresponding modulation and coding scheme for each spatial subchannel according to the received MCI (modulation coding information, ie "segment bow"). The transmit and encoder further determines the transmit power and transmit beam direction of each spatial subchannel using the obtained CSI based on the determined MCI.

其中，接收机确定每个空间子信道所选择的调制编码方式的过程可参考图 2 所示，包括- 步骤 201，接收机阵列接收信号； The process for the receiver to determine the modulation and coding mode selected by each spatial subchannel can be referred to FIG. 2, including: Step 201, the receiver array receives the signal;

步骤 202，接收机进行信道估计； Step 202: The receiver performs channel estimation.

步骤 203 , 接收机测量每个空间子信道的 SINR或 SNR: Step 203: The receiver measures the SINR or SNR of each spatial subchannel:

步骤 204，与不同调制阶的 SINR/ SNR阈值比较，选择相应的调制阶，关闭低于最低调制阶对应 SINR/ SNR阈值的子信道； Step 204: Compare, according to SINR/SNR thresholds of different modulation orders, select a corresponding modulation step, and turn off a subchannel that is lower than a SINR/SNR threshold corresponding to the lowest modulation order.

步骤 205，将选择的调制阶索引编码，并发送到在反馈信道上发送。 Step 205: Encode the selected modulation order index and send it to send on the feedback channel.

关于 SINR/ SNR、调制方式、阈值以及索引的对应关系，可参考表 1，该表提供了接收机根据 SINR/SNR确定子信道调制^码方式的一个实施例，表中显示， SINR/SNR小于 3dB的子信道将被关闭（close ) , 即表示低增益空间子信道将不使用。 For the correspondence between the SINR/SNR, the modulation mode, the threshold, and the index, refer to Table 1, which provides an embodiment in which the receiver determines the subchannel modulation code according to the SINR/SNR, and the table shows that the SINR/SNR is smaller than The 3dB subchannel will be closed, meaning that the low gain spatial subchannel will not be used.

表 1 Table 1

SINR/SNR (dB) 调制方式索引 SINR/SNR (dB) modulation method index

SINR/SNR >=20 64QAM 4 SINR/SNR >=20 64QAM 4

20〉SINR/SNR>=14 16QAM 3 20>SINR/SNR>=14 16QAM 3

14〉 SINR/SNR>=8 8PSK 2 14> SINR/SNR>=8 8PSK 2

8〉 SINR/SNR>=3 BPSK 1 8> SINR/SNR>=3 BPSK 1

3> SINR/SNR close 0 事实上，接收机将所选择的调制编码方式通知发射机是通过发送 "索引" 的方式实现的。在接收机和发射机中分别存储类似 "字典" 的调制编码表，调制编码表记录有各种调制编码方式，接收机确定每个空间子信道的调制编码方式后，从 "字典" 中找到相应的索引，然后将索引通过反馈信道反馈给发射机。发射机根据索引，从 "字典" 中获得空间子信道相应的调制编码方式。 3> SINR/SNR close 0 In fact, the receiver notifies the transmitter of the selected modulation and coding scheme by sending an "index". A modulation dictionary corresponding to a "dictionary" is stored in the receiver and the transmitter, respectively. The coding table records various modulation and coding modes. After the receiver determines the modulation and coding mode of each spatial subchannel, the corresponding index is found from the "dictionary", and then the index is fed back to the transmitter through the feedback channel. According to the index, the transmitter obtains the corresponding modulation and coding mode of the spatial subchannel from the "dictionary".

本发明还提供了一种每空间子信道的速率和功率控制装置，包括接收机和发射机。 The present invention also provides a rate and power control device for each spatial subchannel, including a receiver and a transmitter.

图 3所示为接收机功能模块图。接收机的结构和信号处理流程如下：接收机物理层信号处理除信道估计，信息解码和解调等通用的功能模块之外，在本发明中还包括空间子信道 SINR/SNR测量或估计、空间子信道调制方式确定和本地存储、子信道调制方式反馈等主要功能模块。接收机测量每个空间子信道的 SINR/SNR后，根据设定的阈值, 从发射机和接收机都已知的调制编码种类中进行空间子信道调制编码方式的选择，然后将所有子信道的调制编码索引通过反馈信道发送到发射机，并进行本地存储，以解调信号。 Figure 3 shows the receiver function block diagram. The structure and signal processing flow of the receiver are as follows: Receiver physical layer signal processing In addition to general functional modules such as channel estimation, information decoding and demodulation, spatial subchannel SINR/SNR measurement or estimation, space is also included in the present invention. The main function modules such as subchannel modulation mode determination and local storage, subchannel modulation mode feedback. After the receiver measures the SINR/SNR of each spatial subchannel, according to the set threshold, the spatial subchannel modulation coding mode is selected from the modulation coding types known to both the transmitter and the receiver, and then all subchannels are selected. The modulation coding index is sent to the transmitter through the feedback channel and stored locally to demodulate the signal.

图 4所示为发射机物理层信号处理结构框图。发射机信号处理 ^程主要包括自适应调制编码和发射预编码，详述如下。 Figure 4 shows the block diagram of the signal processing structure of the physical layer of the transmitter. The transmitter signal processing mainly includes adaptive modulation coding and transmission precoding, which are described in detail below.

a. 1 自适应调制编码。 a. 1 Adaptive modulation coding.

发射机首先从反馈信道获取 MCI，获得活动空间子信道数目 q。然后，输入数据流进行串并转换（DEMUX ) , 在每个空间子信道上分配发送数据比特，接着在每个子信道上根据 MCI进行调制编码，方法为：每个子信道的调制编码对应 MCI的一个信息位，根据这个信息位，査找调制编码表（发射机和接收机都知道），获得每个子信道的调制阶，再在不同的空间子信道上根据不同的调制阶进行信号调制编码。图 5 为发射机根据 MCI进行自适应调制的细分步骤，如图，包括： The transmitter first acquires the MCI from the feedback channel and obtains the number of active spatial subchannels q. Then, the input data stream is subjected to serial-to-parallel conversion (DEMUX), the transmission data bits are allocated on each spatial subchannel, and then the modulation coding is performed according to the MCI on each subchannel, by: the modulation coding of each subchannel corresponds to one of the MCIs. Information bits, according to this information bit, look up the modulation coding table (known to both the transmitter and the receiver), obtain the modulation order of each subchannel, and then perform signal modulation coding according to different modulation orders on different spatial subchannels. Figure 5 is a subdivision step of the transmitter adaptive modulation according to MCI, as shown in the figure, including:

步骤 501，发射机从反馈信道获取 MCI，并从 MCI为每个活动子信道分离出 AMC 信息位； Step 501: The transmitter acquires the MCI from the feedback channel, and separates the AMC information bit for each active subchannel from the MCI.

步骤 502, 査找调制编码表，确定每个空间子信道的调制阶； Step 502: Find a modulation and coding table, and determine a modulation order of each spatial subchannel.

步骤 503，根据调制编码选择，为每个空间子信道进行星座映射；步骤 504, 将调制编码信号和 MCI输入预编码器进一步处理。 Step 503: Perform constellation mapping for each spatial subchannel according to modulation coding selection. Step 504: further process the modulated coded signal and the MCI input precoder.

a. 2 发射预编码 a. 2 transmit precoding

如图 4所示，发射机包括有预编码参数处理模块 30，图 6所示为预编码参数处理模块的功能框图，预编码处理包括空间子信道功率分配（ΡΓ·· Ρ ) 和发射波束形成 (w, w,)两个主要功能，图 6中分别对应为空间子信道功率分配模块 301 , 信道参数的信道估计模块 302和奇异值分解（SVD) 模块 303。由于预编码处理需要发射机知道当前信道状态信息，在本发明中，发射机通过反馈信道或直接估计反向信道来获得当前信道状态信息的统计值，然后用统计值来估计当前的信道状态信息 H。用信道均值和发射相关矩阵来估计当前信道信息的一个实施例为：首先，获得信道均值和发射相关矩阵，假设 Hi为实时信道信息估计， L为信道相关时间长度或观察窗宽度，那么信道均值 ^和发射相关矩阵 R_t为： As shown in FIG. 4, the transmitter includes a precoding parameter processing module 30, and FIG. 6 is a functional block diagram of the precoding parameter processing module. The precoding process includes spatial subchannel power allocation (ΡΓ·· Ρ ) and transmit beamforming. (w, w,) two main functions, respectively, corresponding to the spatial subchannel power allocation module 301 in Figure 6, Channel estimation module 302 for channel parameters and singular value decomposition (SVD) module 303. Since the precoding process requires the transmitter to know the current channel state information, in the present invention, the transmitter obtains the statistical value of the current channel state information through the feedback channel or directly estimates the reverse channel, and then uses the statistical value to estimate the current channel state information. H. One embodiment for estimating the current channel information by using the channel mean and the transmit correlation matrix is: First, the channel mean and the transmit correlation matrix are obtained, assuming Hi is the real-time channel information estimate, L is the channel correlation time length or the observation window width, then the channel mean ^ and the emission correlation matrix R _t is:

1 0 1 0

i=- L+\

这里， N为接收天线元数目。那么，当前信道信息的估计为

Here, N is the number of receiving antenna elements. Then, the estimate of the current channel information is

这里， 1^为 >< 维复高斯随机矩阵，其元素具有零均值、单位方差。 N, 为发射天线元数目。 Here, 1^ is a >< complex complex Gaussian random matrix whose elements have zero mean and unit variance. N, is the number of transmitting antenna elements.

获取波束赋形向量 wn主要过程包括：首先，发射机对信道矩阵估计 H进行奇异值 (SVD)分解，可表示为 H=UDV^H，其中， D为对角矩阵，对角线元素的平方表示子信道增益，非零对角线元素个数表示可用空间子信道数目。取 D的对角线上 q个非零数字，进行平方操作后就是 q个活动子信道的增益。然后，取 V的前 q列列向量，即为发射波束赋形向量 wd,。 The main process of obtaining the beamforming vector wn includes: First, the transmitter performs a singular value (SVD) decomposition on the channel matrix estimate H, which can be expressed as H=UDV ^H , where D is a diagonal matrix, and the square representation of the diagonal elements Subchannel gain, the number of non-zero diagonal elements indicates the number of available spatial subchannels. Take q non-zero digits on the diagonal of D, and the square operation is the gain of q active subchannels. Then, take the front q column column vector of V, which is the transmit beam shaping vector wd.

图 7为获取波束赋形向量 _W|〜w,的细分处理流程，如图，包括： 7 is a subdivision processing flow for acquiring a beamforming vector _W| ~ _w , as shown in the figure, including:

步骤 701，发射机估计信道状态信息； Step 701: The transmitter estimates channel state information.

步骤 702，对估计信道状态信息矩阵进行奇异值分解 ( SVD); Step 702: Perform singular value decomposition (SVD) on the estimated channel state information matrix.

步骤 703 , 根据输入 MCI获得活动子信道数目 q; Step 703: Obtain a number of active subchannels according to the input MCI.

步骤 704，输出 q个活动子信道增益，为 q个最大特征值的平方； Step 704, output q active subchannel gains, which are squares of q maximum eigenvalues;

步骤 705，取 SVD分解的 q个最大特征值对应的右特征向量作为子信道发射波束方向向量 wl ,"wq。 Step 705, taking the right feature vector corresponding to the q largest eigenvalues of the SVD decomposition as the subchannel transmitting beam direction vector wl, "wq.

发射功率的分配需要 q个活动子信道 & l增益, 在本发明中, 还加入了调^编码的信息，因此，在具体实施中，可以在给定频谱效率的^件下， W最大化*** 容量、最小化目标误码率或最小化均方误差等进行优化发射功率分配。图 8为发射功率分配处理流程图，如图，包括如下步骤： The allocation of the transmission power requires q active subchannels & l gains. In the present invention, the information of the modulation and coding is also added. Therefore, in a specific implementation, the system can be maximized under the given spectral efficiency. Optimize transmit power allocation by minimizing capacity, minimizing target bit error rate, or minimizing mean square error. FIG. 8 is a flowchart of a transmission power allocation process, as shown in the figure, including the following steps:

步骤 801，根据 MCI获得子信道调制编码信息； Step 801: Obtain subchannel modulation and coding information according to the MCI.

步骤 802，输入活动子信道增益； Step 802, input an active subchannel gain;

步骤 803，空间子信道优化发射功率分配，获得 q个活动空间子信道的发射功率分配 ρ,— ρ^ Step 803: The spatial subchannel optimizes the transmit power allocation, and obtains the transmit power allocation of the q active spatial subchannels ρ, — ρ^

空间子信道功率分配的一个实施例为在总的发射功率 Ρτ的约束下，最小化系统误码率（BER) 的空间子信道最优化功率分配。其约束优化方程可以表示为方程（4 ): 纖, ) One embodiment of spatial subchannel power allocation is to minimize the spatial subchannel optimization power allocation of the system error rate (BER) under the constraint of total transmit power Ρτ. Its constrained optimization equation can be expressed as a square (4): fiber, )

这里，为第 i个空间子信道的信干噪比；为 Q函数，依据方程（5 ) 定义； a, Μ,为第 i个空间子信道的调制阶数，依

据 MCI给出。通过求解方程（4 ), 获得为每个空间子信道的优化发射功率分配。

Here, is the signal to interference and noise ratio of the i-th spatial subchannel; is a Q function, defined according to equation (5); a, Μ, is the modulation order of the i-th spatial subchannel,

According to MCI. By solving equation (4), an optimized transmit power allocation for each spatial subchannel is obtained.

由上可知。本发明在考虑了 AMC的同时，也考虑了自适应发射功率分配与发射波束赋形，即 AMC与 pre-coding级联设计；基于发射机信道状态信息的不可靠性和调制阶的离散性和有限性，本发明采用了接收机信号处理与 AMC决策反馈的策略，即每个空间子信道的调制编码方式由接收机处理决策，然后只将决策结果反馈给发射机，而预编码仍然由发射机根据估计的 CSI进行设计。本发明在实现复杂度、性能和可实现性上都取得了平衡和提高。因此，本发明具有以下主要特 It can be seen from the above. The present invention considers AMC, and also considers adaptive transmit power allocation and transmit beamforming, that is, AMC and pre-coding cascade design; unreliability based on transmitter channel state information and dispersion of modulation order Limitation, the present invention adopts a strategy of receiver signal processing and AMC decision feedback, that is, the modulation coding mode of each spatial subchannel is processed by the receiver, and then only the decision result is fed back to the transmitter, and the precoding is still transmitted by the receiver. The machine is designed according to the estimated CSI. The present invention achieves a balance and improvement in achieving complexity, performance, and achievability. Therefore, the present invention has the following main features

1 ) AMC是接收机根据测量的空间子信道的 SINR/SNR和设定阈值确定的，反馈最终的调制编码选择索引。接收机根据估计的信道状态信息，确定每个子信道的调制编码方式后，从 "字典" 中找到相应的索引，然后将索引通过反馈信道反馈给发射机。发射机根据索引，从 "字典" 中获得相应的调制编码方式。 1) The AMC is determined by the receiver based on the measured SINR/SNR of the spatial subchannel and a set threshold, and the final modulation coding selection index is fed back. The receiver determines the modulation and coding scheme of each subchannel based on the estimated channel state information, finds the corresponding index from the "dictionary", and then feeds the index back to the transmitter through the feedback channel. According to the index, the transmitter obtains the corresponding modulation and coding method from the "dictionary".

2 ) 发射预编码是根据发射机侧获得的信道状态信息的统计信息和反馈的 MCI共同确定的，即发射功率分配是发射机侧估计信道条件、子信道调制编码方式等因素共同决定的；预编码不直接使用瞬时信道状态信息，而是使用信道状态信息的统计信息（CSI ) , 如均值、方差和相关矩阵参数。这些 CSI的获得有以下几种方式： 1 ) 在 TDD***中，发射机通过估计反向信道，在一个比较长的时间段或时间窗内，利用获得反向信道估计，获得前向信道的统计信息，如信道均值等。 2) 在 FDD***，接收机估计信道信息后，计算信道的统计信息，如信道均值等，然后通过反馈信道发送给发射机。 2) The transmission precoding is based on the statistical information and feedback of the channel state information obtained by the transmitter side. The MCI jointly determines that the transmit power allocation is jointly determined by the transmitter-side estimated channel condition and the sub-channel modulation and coding mode; the pre-coding does not directly use the instantaneous channel state information, but uses the channel state information statistical information (CSI). , such as mean, variance, and correlation matrix parameters. These CSIs are obtained in the following ways: 1) In the TDD system, the transmitter obtains the statistics of the forward channel by estimating the reverse channel and obtaining the reverse channel estimate over a relatively long period of time or time window. Information, such as channel mean, etc. 2) In the FDD system, after the receiver estimates the channel information, it calculates the channel's statistical information, such as the channel mean, etc., and then sends it to the transmitter through the feedback channel.

3 ) 复杂度、可实现性和性能合理平衡的 AMC与 pre- coding级联设计结构。特别的，本发明大大降低了反馈信息量。 3) AMC and pre-coding cascaded design structures with reasonable balance of complexity, achievability and performance. In particular, the present invention greatly reduces the amount of feedback information.

正因为本发明具有以上特点，所以相对现有技术具有以下优势： Because the present invention has the above characteristics, it has the following advantages over the prior art:

1 ) 利用接收机侧获得的近似完美的信道状态信息，本发明的 AMC能够比较准确地反映快速的无线信道变化，获得较好的鲁棒性能；其次，降低了反馈信道的带宽需求。' 1) Using the approximate channel state information obtained by the receiver side, the AMC of the present invention can accurately reflect the fast wireless channel variation and obtain better robust performance. Secondly, the bandwidth requirement of the feedback channel is reduced. '

2 ) 本发明降低了发射机的实现复杂度。虽然现有技术的全自适应 AMC级联发射预编码设计理论上是性能最优化的，但是，实现复杂度很高，导致信号处理延迟大，在快速变化无线环境下性能大大降低。此外，由于实际***的调制编码的离散特性，现有技术的最优化实现获得调制编码必须服从于有限的离散的调制编码方式，从而导致性能员失。 2) The present invention reduces the implementation complexity of the transmitter. Although the prior art fully adaptive AMC cascading transmit precoding design is theoretically optimized in performance, the implementation complexity is high, resulting in large signal processing delays and greatly reduced performance in rapidly changing wireless environments. In addition, due to the discrete nature of the modulation coding of the actual system, the prior art optimization implementation to obtain modulation coding must be subject to a limited discrete modulation coding mode, resulting in performance loss.

3 ) 本发明更有利子实际***实现。通常， AMC***只能使用有限信号调制编码方式，所以，该方法在性能与实现复杂度上进行了折中考虑。 3) The present invention is more advantageous to implement the actual system. In general, the AMC system can only use finite signal modulation coding, so this method compromises performance and implementation complexity.

以上所述仅是本发明的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以作出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。 The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. It is considered as the scope of protection of the present invention.

Claims

权利要求 Rights request

1. 一种每空间子信道的速率和功率控制方法，其特征在于，包括如下步骤: 步骤一，接收机根据接收机侧估计的信道状态信息，确定每个空间子信道的调制编码方式； A method for controlling a rate and power of a spatial subchannel, comprising the following steps: Step 1: The receiver determines a modulation and coding mode of each spatial subchannel according to channel state information estimated by the receiver side;

2. 根据权利要求 1所述的方法，其特征在于，所述步骤二包括： 2. The method according to claim 1, wherein the step two comprises:

步骤 b , 接收机根据在所述调制编码表中不同空间子信道所选择的调制编码方式的位置来确定索引信息； Step b, the receiver determines the index information according to the location of the modulation and coding mode selected by the different spatial subchannels in the modulation and coding table;

步骤 c , 接收机将所述索引信息通过反馈信道发送给发射机； Step c, the receiver sends the index information to the transmitter through a feedback channel;

步骤 d , 发射机根据所述索引信息在所述调制编码表中找到不同空间子信道所选择的调制编码方式，并确定使用的空间子信道数 g q。 Step d: The transmitter finds a modulation and coding mode selected by different spatial subchannels in the modulation and coding table according to the index information, and determines a number of spatial subchannels used.

3. 根据权利要求 2所述的方法，其特征在于，所述步骤一包括： 3. The method according to claim 2, wherein the step one comprises:

步骤 A , 接收机测量和计每个空间子信道的信干噪比 /信噪比； Step A, the receiver measures and measures the signal to interference and noise ratio/signal to noise ratio of each spatial subchannel;

步骤 B，将每个空间子信道的信干噪比 /信噪比与设定的阇值进行比较，根据阈值对应的调制阶为每个空间子信道选择对应的调制编码方式。 Step B: Compare the signal to interference/noise ratio/signal-to-noise ratio of each spatial subchannel with the set threshold value, and select a corresponding modulation and coding mode for each spatial subchannel according to the modulation order corresponding to the threshold.

4. 根据权利要求 1所述的方法，其特征在于，所述统计值为信道状态信息的均值、方差和 /或相关矩阵参数。 4. The method according to claim 1, wherein the statistical value is a mean, a variance and/or a correlation matrix parameter of channel state information.

5. 根据权利要求 4所述的方法，其特征在于，在所述步骤三中，如果是处于时分双工***的条件下，则通过如下方式确定所述统计值：发射机通过估计反向信道，利用在一个信道相干时间段或设定的时间窗内获得的反向信道估计来计算所述统计值。 The method according to claim 4, wherein in the step 3, if it is under the condition of a time division duplex system, the statistical value is determined by: the transmitter estimates the reverse channel The statistical value is calculated using a reverse channel estimate obtained within a channel coherence time period or a set time window.

6. 根据权利要求 4所述的方法，其特征在于，在所述步骤三中，如果是处于频分双工***的条件下，则通过如下方式确定所述统计值：接收机利用在一个信道相干时间段或设定的时间窗内获得的信道状态信息来计算所述统计值，并通过反馈信道将所述统计值反馈给发射机。 The method according to claim 4, wherein in the step 3, if it is under the condition of a frequency division duplex system, the statistical value is determined by: using a receiver in a channel Channel state information obtained within a coherent time period or a set time window to calculate the statistical value The feedback channel feeds the statistical value back to the transmitter.

7. 一种每空间子信道的速率和功率控制装置，其特征在于，包括：接收机，用于根据接收机侧估计的信道状态信息，确定每个空间子信道所选择的调制编码方式，并将所选择的调制编码方式通知发射机； A rate and power control apparatus for a spatial subchannel, comprising: a receiver, configured to determine, according to channel state information estimated by a receiver side, a modulation and coding mode selected for each spatial subchannel, and Notifying the transmitter of the selected modulation and coding method;

发射机，用于根据信道状态信息的统计值和各空间子信道的调制编码方式进行预编码。 And a transmitter, configured to perform precoding according to a statistical value of channel state information and a modulation and coding mode of each spatial subchannel.

8. 根据权利要求 7所述的装置，其特征在于，所述发射机中进行预编码处理的部分包括依据信道参数的信道估计模块、奇异值分解模块和空间子信道功率分配模块； 8. The apparatus according to claim 7, wherein the portion of the transmitter that performs precoding processing comprises a channel estimation module, a singular value decomposition module, and a spatial subchannel power allocation module according to channel parameters;

所述依据信道参数的信道估计模块，用于使用所述信道状态信息的统计值来获得当前的信道状态信息矩阵； The channel estimation module according to the channel parameter is configured to obtain a current channel state information matrix by using a statistical value of the channel state information;

所述奇异值分解模块，用于对信道状态信息矩阵进行奇异值分解，得到 q个活动空间子信道的增益，并进一步得到发射波束赋形向量； The singular value decomposition module is configured to perform singular value decomposition on the channel state information matrix to obtain gains of q active spatial subchannels, and further obtain a transmit beamforming vector;

所述空间子信道功率分配模块，用于稂据子信道所选择的调制编码方式和所述 q个活动子信道的增益来确定 q个活动子信道的发射功率分配。 The spatial subchannel power allocation module is configured to determine a transmit power allocation of the q active subchannels according to a modulation coding mode selected by the subchannel and a gain of the q active subchannels.

9. 根据权利要求 7所述的装置，其特征在于, 所述接收机和所述发射机中都存储有调制编码表，所述调制编码表记录有各种调制编码方式，所述接收机根据在所述调制编码表中不同子信道所选择的调制编码方式的位置来确定索引信息，并将所述索引信息通过反馈信道发送给所述发射机，所述发射机根据所述索引信息在所述调制编码表中找到不同子信道所选择的调制编码方式。 9. The apparatus according to claim 7, wherein a modulation coding table is stored in both the receiver and the transmitter, and the modulation and coding table records various modulation and coding modes, and the receiver is configured according to Determining index information in a position of a modulation coding mode selected by different subchannels in the modulation and coding table, and transmitting the index information to the transmitter through a feedback channel, where the transmitter is located according to the index information The modulation and coding scheme selected by different subchannels is found in the modulation and coding table.

10. 根据权利要求 7或 8所述的装置，其特征在于，所述统计值为信道状态信息的均值、方差和 /或相关矩阵参数。 10. Apparatus according to claim 7 or 8, wherein the statistical value is a mean, a variance and/or a correlation matrix parameter of channel state information.

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