CN102130877A

CN102130877A - Pilot signal determining method and wireless communication system thereof

Info

Publication number: CN102130877A
Application number: CN2011100213517A
Authority: CN
Inventors: 廖彦钦; 吴承轩; 杜勇赐
Original assignee: RALINK TECHNOLOGY CORP
Current assignee: RALINK TECHNOLOGY CORP
Priority date: 2010-01-19
Filing date: 2011-01-19
Publication date: 2011-07-20

Abstract

A pilot signal determining method and a wireless communication system thereof are provided, the pilot signal determining method is used in a wireless communication system, the wireless communication system utilizes a plurality of sub-carriers for transmission. The pilot signal determining method includes generating at least one vector corresponding to at least one subchannel; and determining a plurality of pilot signals according to the at least one vector.

Description

Guide signal determination method and wireless communication system thereof

技术领域technical field

本发明涉及一种引导(pilot)信号决定方法及其无线通信系统，尤其涉及一种可用来决定引导信号的数量、引导位置及引导值的引导信号决定方法及其无线通信系统。The present invention relates to a pilot signal determining method and its wireless communication system, in particular to a pilot signal determining method and its wireless communication system which can be used to determine the quantity, pilot position and pilot value of pilot signals.

背景技术Background technique

正交频分复用(Orthogonal Frequency Division Multiplexing，OFDM)调制技术是种「多载波调制」(Multi Carrier Modulation，MCM)传输方法，其基本的概念是把一个高速传输速率的数据串流，切割成许多平行且较低速的传输速率串流，并且把每一个子串流(又称为次串流)调制到不同的子载波(Sub-carrier，又称为次载波)上。在此情形下，符元(Symbol)时间变得够长，所以通道导致的延迟变得只是符码时间的一小部分，因而可消除或减少符码间干扰(Inter Symbol Interference)，有效提升频谱利用率(spectrum efficiency)，增加系统的数据传输量。因此，正交频分复用调制技术已广泛地用于许多无线通信系统中，例如无线局域网(Wireless LocalArea Network，WLAN)就是其中之一，相关无线局域网通信协议标准包含IEEE 802.11a、IEEE 802.11b、IEEE 802.11g，至IEEE 802.11n等，均采用正交频分复用调制技术。其中，与IEEE 802.11a/g标准不同的是，IEEE802.11n标准使用可支持多个空间时间束(space time stream)的多输入多输出(Multiple Input Multiple Output，MIMO)技术及其它新功能，大幅改善了数据速率及传输吞吐量(Throughput)，同时，通道频宽由20MHz增加为40MHz。Orthogonal Frequency Division Multiplexing (OFDM) modulation technology is a "Multi Carrier Modulation" (Multi Carrier Modulation, MCM) transmission method. Its basic concept is to cut a high-speed data stream into There are many parallel and relatively low-speed transmission rate streams, and each sub-stream (also called sub-stream) is modulated onto a different sub-carrier (also called sub-carrier). In this case, the symbol (Symbol) time becomes long enough, so the delay caused by the channel becomes only a small part of the symbol time, thus eliminating or reducing the Inter Symbol Interference (Inter Symbol Interference), effectively improving the spectrum Utilization (spectrum efficiency) increases the data transmission volume of the system. Therefore, OFDM modulation technology has been widely used in many wireless communication systems, such as wireless local area network (Wireless Local Area Network, WLAN) is one of them, and related wireless local area network communication protocol standards include IEEE 802.11a, IEEE 802.11b , IEEE 802.11g, to IEEE 802.11n, etc., all adopt OFDM modulation technology. Among them, different from the IEEE 802.11a/g standard, the IEEE802.11n standard uses the Multiple Input Multiple Output (MIMO) technology and other new functions that can support multiple space time beams (space time stream), greatly Improved data rate and throughput (Throughput), at the same time, channel bandwidth increased from 20MHz to 40MHz.

为了使接收器进行通道估计以取得通道响应，通信系统通常使用引导信号做为参考信号以更正频率及时序误差。具体而言，部分子载波专属用来传输引导信号，即引导频道(pilot tone)，接收器可对其进行辨视。因此，接收器可对该部分子载波进行通道估计以取得相对应通道响应，进而通过内差决定其它子载波的通道响应。In order for the receiver to perform channel estimation to obtain the channel response, the communication system usually uses the pilot signal as a reference signal to correct frequency and timing errors. Specifically, some subcarriers are exclusively used to transmit pilot signals, ie, pilot tones, which can be identified by a receiver. Therefore, the receiver can perform channel estimation on the part of the subcarriers to obtain the corresponding channel responses, and then determine the channel responses of other subcarriers through interpolation.

在一频宽为20MHz的正交频分复用系统中，其使用64个子载波及并将子载波编号为-32、-31、...、31。在这些子载波中，编号为-21、-7、7及21的4个子载波(sub-carriers)专属用来传输引导信号，即引导频道。如图1所示，图1是频宽为20MHz的正交频分复用系统中引导位置的示意图，其具有4个引导信号，且引导信号的引导位置分别为-21、-7、7及21。In an OFDM system with a bandwidth of 20 MHz, 64 subcarriers are used and the subcarriers are numbered -32, -31, . . . , 31. Among these sub-carriers, four sub-carriers (sub-carriers) numbered -21, -7, 7 and 21 are exclusively used to transmit pilot signals, ie, pilot channels. As shown in Figure 1, Figure 1 is a schematic diagram of pilot positions in an OFDM system with a bandwidth of 20MHz, which has 4 pilot signals, and the pilot positions of the pilot signals are -21, -7, 7 and twenty one.

对符合IEEE802.11a/g标准的无线系统而言，即使用一个串流进行传输，用于各正交频分复用符元中引导信号的引导值可表示为p(k)，其中k＝-7、-21、7及21，其引导值如下：For a wireless system conforming to the IEEE802.11a/g standard, that is, using one stream for transmission, the pilot value used for the pilot signal in each OFDM symbol can be expressed as p(k), where k= -7, -21, 7 and 21, the boot values are as follows:

p(-21)＝1、p(-7)＝1、p(7)＝1、p(21)＝-1。p(-21)=1, p(-7)=1, p(7)=1, p(21)=-1.

对符合IEEE802.11n标准的无线系统而言，其可支持N_STS个空间时间束，其中，1≤NSTS≤4。用于一第n个正交频分复用符元中N_STS个空间时间束中一第i_STS个空间时间束上一第k个子载波的一引导信号的一引导值可表示如下：For a wireless system conforming to the IEEE802.11n standard, it can support N _STS space-time bundles, where 1≤NSTS≤4. A pilot value for a pilot signal _of a k-th subcarrier on an i-th space-time beam among N _STS space-time beams in an n-th OFDM symbol can be expressed as follows:

$k k = = - - 21 twenty one : : p p (({N N}_{STS STS},, {i i}_{STS STS},, n no)) = = Ψ Ψ (({N N}_{STS STS},, {i i}_{STS STS},, n no &CirclePlus; &CirclePlus; 44))$

$k k = = - - 77 : : p p (({N N}_{STS STS},, {i i}_{STS STS},, n no)) = = Ψ Ψ (({N N}_{STS STS},, {i i}_{STS STS},, ((n no + + 11)) &CirclePlus; &CirclePlus; 44))$

$k k = = 77 : : p p (({N N}_{STS STS},, {i i}_{STS STS},, n no)) = = Ψ Ψ (({N N}_{STS STS},, {i i}_{STS STS},, ((n no + + 22)) &CirclePlus; &CirclePlus; 44))$

$k k = = 21 twenty one : : p p (({N N}_{STS STS},, {i i}_{STS STS},, n no)) = = Ψ Ψ (({N N}_{STS STS},, {i i}_{STS STS},, ((n no + + 33)) &CirclePlus; &CirclePlus; 44))$

其中

表示模运算，而ψ定义于图2中，图2为频宽为20MHz且符合IEEE802.11n标准的正交频分复用系统的一引导值表20的示意图。in

represents a modulo operation, and ψ is defined in FIG. 2 . FIG. 2 is a schematic diagram of a boot value table 20 of an OFDM system with a bandwidth of 20 MHz and conforming to the IEEE802.11n standard.

以用于一第3个正交频分复用符元中于4个空间时间束中一第3个空间时间束上引导信号的引导值为例，该引导值可通过参考引导值表20的一列R9而得。具体而言，用于第3个正交频分复用符元中于4个空间时间束中第3个空间时间束上第-21个、第-7个、第7个及第21个子载波的引导值分别为

即1，1，-1，1，其可由图2中一虚线所示的由列R9第4个引导值开始至列R9第3个引导值结束的顺序而得。依此类推，可得到其它引导值。Taking the pilot value used for the pilot signal on a 3rd space-time beam among 4 space-time beams in a 3rd OFDM symbol as an example, the pilot value can be obtained by referring to the pilot value table 20 A column of R9 is obtained. Specifically, it is used for the -21st, -7th, 7th, and 21st subcarriers on the third space-time beam among the four space-time beams in the third OFDM symbol The bootstrap values for

That is, 1, 1, -1, 1, which can be obtained from the sequence shown by a dotted line in FIG. 2 starting from the 4th leading value of column R9 to ending with the 3rd leading value of column R9. By analogy, other boot values can be obtained.

值得注意的是，为了使一接收器更精确进行通道估计，用于不同正交频分复用符元中一空间时间束上子载波的引导值序列优选为彼此正交。以用于第3个及第4个正交频分复用符元中于4个空间时间束中一第3个空间时间束上引导信号的引导值序列为例，用于第3个正交频分复用符元的引导值序列为

而用于第4个正交频分复用符元的引导值序列为

其彼此正交，即1-1-1+1＝0，使得接收器所进行的通道估计具有统计上的多元性而非一再估计不同正交频分复用符元中相同的误差。相似地，用于正交频分复用符元中一空间时间束上不同子载波的引导值序列亦优选为彼此正交，而用于正交频分复用符元中不同空间时间束上子载波的引导值序列亦优选为彼此正交。It should be noted that, in order for a receiver to perform channel estimation more accurately, the pilot value sequences used for subcarriers on a space-time beam in different OFDM symbols are preferably orthogonal to each other. Take the pilot value sequence used for the pilot signal on the 3rd space-time beam among the 4 space-time beams in the 3rd and 4th OFDM symbols as an example, for the 3rd orthogonal The leading value sequence of the frequency division multiplexing symbol is

And the leading value sequence for the 4th OFDM symbol is

They are orthogonal to each other, ie 1-1-1+1=0, so that the channel estimation by the receiver is statistically multivariate instead of repeatedly estimating the same error in different OFDM symbols. Similarly, the pilot value sequences used for different subcarriers on a space time beam in an OFDM symbol are also preferably orthogonal to each other, while the pilot value sequences used in different space time beams in an OFDM symbol The sequences of pilot values of the subcarriers are also preferably orthogonal to each other.

在一频宽为40MHz且符合IEEE802.11n标准的正交频分复用系统中，其使用128个子载波，且编号为-53、-25、-11、11、25及53的6个子载波专属用来传输引导信号，即引导频道。如图3所示，图3是频宽为40MHz的正交频分复用系统中引导位置的示意图，其具有6个引导信号，且引导信号的引导位置分别为-53、-25、-11、11、25及53。用于一第n个正交频分复用符元中N_STS个空间时间束中一第i_STS个空间时间束上一第k个子载波的一引导信号的一引导值可表示如下：In an OFDM system with a bandwidth of 40MHz and conforming to the IEEE802.11n standard, it uses 128 subcarriers, and the 6 subcarriers numbered -53, -25, -11, 11, 25 and 53 are dedicated It is used to transmit the pilot signal, that is, the pilot channel. As shown in Figure 3, Figure 3 is a schematic diagram of pilot positions in an OFDM system with a bandwidth of 40MHz, which has 6 pilot signals, and the pilot positions of the pilot signals are -53, -25, and -11 respectively , 11, 25 and 53. A pilot value for a pilot signal _of a k-th subcarrier on an i-th space-time beam among N _STS space-time beams in an n-th OFDM symbol can be expressed as follows:

$k k = = - - 5353 : : p p (({N N}_{STS STS},, {i i}_{STS STS},, n no)) = = Ψ Ψ (({N N}_{STS STS},, {i i}_{STS STS},, n no &CirclePlus; &CirclePlus; 66))$

$k k = = - - 2525 : : p p (({N N}_{STS STS},, {i i}_{STS STS},, n no)) = = Ψ Ψ (({N N}_{STS STS},, {i i}_{STS STS},, ((n no + + 11)) &CirclePlus; &CirclePlus; 66))$

$k k = = - - 1111 : : p p (({N N}_{STS STS},, {i i}_{STS STS},, n no)) = = Ψ Ψ (({N N}_{STS STS},, {i i}_{STS STS},, ((n no + + 22)) &CirclePlus; &CirclePlus; 66))$

$k k = = 1111 : : p p (({N N}_{STS STS},, {i i}_{STS STS},, n no)) = = Ψ Ψ (({N N}_{STS STS},, {i i}_{STS STS},, ((n no + + 33)) &CirclePlus; &CirclePlus; 66))$

$k k = = 2525 : : p p (({N N}_{STS STS},, {i i}_{STS STS},, n no)) = = Ψ Ψ (({N N}_{STS STS},, {i i}_{STS STS},, ((n no + + 44)) &CirclePlus; &CirclePlus; 66))$

$k k = = 5353 : : p p (({N N}_{STS STS},, {i i}_{STS STS},, n no)) = = Ψ Ψ (({N N}_{STS STS},, {i i}_{STS STS},, ((n no + + 55)) &CirclePlus; &CirclePlus; 66))$

其中

表示模运算，而ψ被定义于图4中，图4为频宽为40MHz且符合IEEE802.11n标准的正交频分复用系统的一引导值表40的示意图。引导值表40与引导值表20相似，其详细说明及用法可参考之前叙述。in

represents a modulo operation, and ψ is defined in FIG. 4 . FIG. 4 is a schematic diagram of a boot value table 40 of an OFDM system with a bandwidth of 40 MHz and conforming to the IEEE802.11n standard. The guide value table 40 is similar to the guide value table 20 , and its detailed description and usage can refer to the previous description.

为了达到高品质的无线局域网传输，IEEE委员会正在开发下一代无线局域网系统，如符合IEEE802.11ac标准的多用户多输入多输出(multi-stationmultiple input multiple output，MU-MIMO)系统，其可将通道频宽由40MHz增加至80MHz或甚至160MHz，且可支持4个以上天线，即4个以上空间时间束。In order to achieve high-quality WLAN transmission, the IEEE committee is developing next-generation WLAN systems, such as a multi-station multiple input multiple output (MU-MIMO) system that complies with the IEEE802.11ac standard. The bandwidth is increased from 40MHz to 80MHz or even 160MHz, and it can support more than 4 antennas, that is, more than 4 space-time beams.

由于通信系统使用引导信号做为参考信号以更正频率及时序误差，进而更精确进行通道估计，因此必须决定用于下一代无线局域网系统中的引导信号。Since the communication system uses the pilot signal as a reference signal to correct frequency and timing errors, thereby performing more accurate channel estimation, it is necessary to determine the pilot signal used in the next generation WLAN system.

发明内容Contents of the invention

因此，本发明的主要目的即在于提供一种可用来决定引导信号的数量、引导位置及引导值的引导信号决定方法及其无线通信系统。Therefore, the main purpose of the present invention is to provide a pilot signal determining method and a wireless communication system thereof which can be used to determine the number, position and value of pilot signals.

本发明还公开一种信号决定方法，用于一无线通信系统中，该无线通信系统利用多个子载波传输。该引导信号决定方法包含有产生对应于至少一子通道的至少一向量；以及根据该至少一向量决定多个引导信号。The invention also discloses a signal determination method, which is used in a wireless communication system, and the wireless communication system uses multiple sub-carriers for transmission. The pilot signal determining method includes generating at least one vector corresponding to at least one sub-channel; and determining a plurality of pilot signals according to the at least one vector.

本发明还公开一种无线通信系统，利用多个子载波进行传输。该无线通信系统包含有一微处理器；以及一存储器，用来存储一程序，以指示该微处理器执行上述的引导信号决定方法。The invention also discloses a wireless communication system, which utilizes multiple sub-carriers for transmission. The wireless communication system includes a microprocessor; and a memory for storing a program to instruct the microprocessor to execute the above-mentioned guide signal determining method.

附图说明Description of drawings

图1是一频宽为20MHz的正交频分复用系统中引导位置的示意图。FIG. 1 is a schematic diagram of pilot positions in an OFDM system with a bandwidth of 20 MHz.

图2为一频宽为20MHz且符合IEEE802.11n标准的正交频分复用系统的一引导值表的示意图。FIG. 2 is a schematic diagram of a boot value table of an OFDM system with a bandwidth of 20 MHz and conforming to the IEEE802.11n standard.

图3是一频宽为40MHz的正交频分复用系统中引导位置的示意图。FIG. 3 is a schematic diagram of pilot positions in an OFDM system with a bandwidth of 40 MHz.

图4为一频宽为40MHz且符合IEEE802.11n标准的正交频分复用系统的一引导值表的示意图。FIG. 4 is a schematic diagram of a boot value table of an OFDM system with a bandwidth of 40 MHz and conforming to the IEEE802.11n standard.

图5为本发明实施例中一引导信号决定流程的示意图。FIG. 5 is a schematic diagram of a pilot signal determination process in an embodiment of the present invention.

图6为本发明实施例中一频宽为80MHz的正交频分复用系统中用于偶数正交频分复用符元及奇数正交频分复用符元的一向量表的示意图。6 is a schematic diagram of a vector table for even OFDM symbols and odd OFDM symbols in an OFDM system with a bandwidth of 80 MHz according to an embodiment of the present invention.

图7为本发明实施例一引导值决定流程的示意图。FIG. 7 is a schematic diagram of a guide value determination process according to an embodiment of the present invention.

图8为本发明实施例中一引导值决定流程的示意图。FIG. 8 is a schematic diagram of a guide value determination process in an embodiment of the present invention.

图9为本发明实施例中用于一频宽为80MHz的正交频分复用系统的一引导值矩阵的示意图。FIG. 9 is a schematic diagram of a pilot value matrix used in an OFDM system with a bandwidth of 80 MHz in an embodiment of the present invention.

【主要元件符号说明】[Description of main component symbols]

20、40 引导值表20, 40 Guide value table

R1～R9、R1′～R9′ 列R1～R9, R1′～R9′ Columns

50、70、80 流程50, 70, 80 Process

500～506、700～708、800～806 步骤500～506, 700～708, 800～806 Steps

60 向量表60 Vector table

Q 引导值矩阵Q Bootstrap value matrix

具体实施方式Detailed ways

请参考图5，图5为本发明实施例中一引导信号决定流程50的示意图。引导信号决定流程50用于一无线通信系统中决定引导信号，该无线通信系统利用多个子载波进行传输。引导信号决定流程50包含有以下步骤：Please refer to FIG. 5 , which is a schematic diagram of a pilot signal determination process 50 in an embodiment of the present invention. The pilot signal determining process 50 is used for determining a pilot signal in a wireless communication system, and the wireless communication system utilizes multiple subcarriers for transmission. The pilot signal decision process 50 includes the following steps:

步骤500：开始。Step 500: start.

步骤502：产生对应于至少一子通道的至少一向量。Step 502: Generate at least one vector corresponding to at least one sub-channel.

步骤504：根据该至少一向量决定多个引导信号。Step 504: Determine a plurality of pilot signals according to the at least one vector.

步骤506：结束。Step 506: end.

根据引导信号决定流程50，本发明先产生对应于至少一子通道的至少一向量，然后再根据至少一向量决定多个引导信号。According to the pilot signal determination process 50, the present invention first generates at least one vector corresponding to at least one sub-channel, and then determines a plurality of pilot signals according to the at least one vector.

以符合IEEE802.11无线局域网(Wireless Local Area Network，WLAN)标准的一无线通信系统为例，本发明产生至少一向量

其中，s表示该至少一子通道的一第s个子通道，而i＝0、1、2、3时φ_i ^(s)＝{0，1}。值得注意的是，φ_i ^(s)的值与至少一向量

的数量根据IEEE802.11无线局域网标准所设定，如IEEE802.11a/g、IEEE802.11n或IEEE802.11ac。如此一来，本发明可加总φ_i ^(s)的值以做为一空间时间束上引导信号的一数量L，其可表示为：Taking a wireless communication system conforming to IEEE802.11 wireless local area network (Wireless Local Area Network, WLAN) standard as an example, the present invention generates at least one vector

Wherein, s represents an s-th sub-channel of the at least one sub-channel, and when i=0, 1, 2, 3, φ _i ^(s) = {0, 1}. It is worth noting that the value of φ _i ^(s) is related to at least one vector

The number is set according to the IEEE802.11 wireless local area network standard, such as IEEE802.11a/g, IEEE802.11n or IEEE802.11ac. In this way, the present invention can sum up the values of φ _i ^(s) as a quantity L of pilot signals on a space-time beam, which can be expressed as:

$L L = = \underset{s the s}{Σ Σ} \underset{i i}{Σ Σ} {φ φ}_{i i}^{((s the s))} . .$

再者，本发明可另根据该至少一向量及一预设向量，决定该多个引导信号的多个引导位置。具体而言，本发明可根据一公式决定该多个引导信号的该多个引导位置，该公式可表示为：Furthermore, the present invention can also determine a plurality of guiding positions of the plurality of guiding signals according to the at least one vector and a preset vector. Specifically, the present invention can determine the plurality of guiding positions of the plurality of guiding signals according to a formula, and the formula can be expressed as:

其中，

表示该至少一向量，

良示元素对元素相乘，N表示该多个子载波的数量，M表示一子通道中子载波的数量，而表示该预设向量。in,

represents the at least one vector,

It represents element-to-element multiplication, N represents the number of the plurality of subcarriers, M represents the number of subcarriers in a subchannel, and represents the preset vector.

以符合IEEE802.11无线局域网标准的一无线通信系统为例，预设向量优选为[11253953]。对一频宽为20MHz的系统而言，其具有64个子载波、0个子通道，且一通道中具有64个子载波(N＝64，S＝0，M＝64)，本发明可产生至少一向量

然后加总φ_i ^(s)的值做为一空间时间束上引导信号的数量，其可表示为：Taking a wireless communication system conforming to the IEEE802.11 wireless local area network standard as an example, the default vector is preferably [11253953]. For a system with a bandwidth of 20MHz, it has 64 subcarriers, 0 subchannels, and 64 subcarriers (N=64, S=0, M=64) in one channel, the present invention can generate at least one vector

Then sum up the values of φ _i ^(s) as the number of pilot signals on a space-time beam, which can be expressed as:

1+1+1+1＝4。1+1+1+1=4.

接着，本发明计算公式

以决定4个引导信号的引导位置，其可表示为：Then, the calculation formula of the present invention

To determine the guiding positions of the four guiding signals, it can be expressed as:

$[\begin{matrix} 11 & 11 & 11 & 11 \end{matrix}] &CircleTimes; &CircleTimes; ((- - 3232 + + 00 \times \times 6464 + + [\begin{matrix} 1111 & 2525 & 3939 & 5353 \end{matrix}])) = = [\begin{matrix} - - 21 twenty one & - - 77 & 77 & 21 twenty one \end{matrix}] . .$

如此一来，本发明可决定用于一频宽为20MHz的系统的引导信号的引导位置为-21、-7、7及21，其与已知技术相同。In this way, the present invention can determine the pilot positions of the pilot signal for a system with a bandwidth of 20 MHz to be -21, -7, 7 and 21, which is the same as the prior art.

对一频宽为40MHz的系统而言，其具有128个子载波、2个子通道，且一子通道中具有64个子载波(N＝128，S＝0、1，M＝64)，本发明可产生至少一向量

然后加总φ_i ^(s)的值做为一空间时间束上引导信号的数量，其可表示为：For a system with a bandwidth of 40MHz, it has 128 subcarriers, 2 subchannels, and 64 subcarriers (N=128, S=0, 1, M=64) in a subchannel, the present invention can produce at least one vector

(1+0+1+1)+(1+1+0+1)＝6。(1+0+1+1)+(1+1+0+1)=6.

接着，本发明计算公式

并以非零元素做为子通道0的引导位置，其可表示为：Then, the calculation formula of the present invention

And use non-zero elements as the leading position of sub-channel 0, which can be expressed as:

$[\begin{matrix} 11 & 00 & 11 & 11 \end{matrix}] &CircleTimes; &CircleTimes; ((- - 6464 + + 00 \times \times 6464 + + [\begin{matrix} 1111 & 2525 & 3939 & 5353 \end{matrix}])) = = [\begin{matrix} - - 5353 & 00 & - - 2525 & - - 1111 \end{matrix}];;$

且本发明可另计算公式

并以非零元素做为子通道1的引导位置，其可表示为：And the present invention can calculate another formula

And use non-zero elements as the leading position of sub-channel 1, which can be expressed as:

$[\begin{matrix} 11 & 11 & 00 & 11 \end{matrix}] &CircleTimes; &CircleTimes; ((- - 6464 + + 11 \times \times 6464 + + [\begin{matrix} 1111 & 2525 & 3939 & 5353 \end{matrix}])) = = [\begin{matrix} 1111 & 2525 & 00 & 5353 \end{matrix}] . .$

如此一来，本发明可决定用于一频宽为40MHz的系统的引导信号的引导位置为-53、-25、-11、11、25及53，其与已知技术相同。由上述可知，由于本发明所决定用于频宽为20MHz或40MHz的系统的引导信号的引导位置与已知技术相同，因此本发明可向前相容(backward-compatible)于IEEE802.11a/g/n标准。In this way, the present invention can determine the pilot positions of the pilot signal for a system with a bandwidth of 40 MHz to be -53, -25, -11, 11, 25 and 53, which are the same as the prior art. As can be seen from the above, since the pilot position of the pilot signal used in the system with a bandwidth of 20MHz or 40MHz determined by the present invention is the same as that of the known technology, the present invention is backward-compatible with IEEE802.11a/g /n standard.

更进一步地，对一频宽为80MHz的系统而言，其具有256个子载波、4个子通道，且一子通道中具有64个子载波(N＝128，S＝0、1、2、3，M＝64)，本发明可产生至少一向量

然后加总φ_i ^(s)的值做为一空间时间束上引导信号的数量，其可表示为：Furthermore, for a system with a bandwidth of 80MHz, it has 256 subcarriers and 4 subchannels, and there are 64 subcarriers in one subchannel (N=128, S=0, 1, 2, 3, M =64), the present invention can generate at least one vector

(0+1+0+1)+(0+1+0+1)+(1+0+1+0)+(1+0+1+0)＝8。(0+1+0+1)+(0+1+0+1)+(1+0+1+0)+(1+0+1+0)=8.

接着，本发明计算计算公式

$[\begin{matrix} 00 & 11 & 00 & 11 \end{matrix}] &CircleTimes; &CircleTimes; ((- - 128128 + + 00 \times \times 6464 + + [\begin{matrix} 1111 & 2525 & 3939 & 5353 \end{matrix}])) = = [\begin{matrix} 00 & - - 103103 & 00 & - - 7575 \end{matrix}];;$

计算公式

并以非零元素做为子通道1的引导位置，其可表示为：Calculation formula

$[\begin{matrix} 00 & 11 & 00 & 11 \end{matrix}] &CircleTimes; &CircleTimes; ((- - 128128 + + 11 \times \times 6464 + + \begin{matrix} \end{matrix} [\begin{matrix} 1111 & 2525 & 3939 & 5353 \end{matrix}])) = = [\begin{matrix} 00 & - - 3939 & 00 & - - 1111 \end{matrix}];;$

计算公式

并以非零元素做为子通道2的引导位置，其可表示为：Calculation formula

And use non-zero elements as the leading position of sub-channel 2, which can be expressed as:

$[\begin{matrix} 11 & 00 & 11 & 00 \end{matrix}] &CircleTimes; &CircleTimes; ((- - 128128 + + 22 \times \times 6464 + + [\begin{matrix} 1111 & 2525 & 3939 & 5353 \end{matrix}])) = = [\begin{matrix} 1111 & 00 & 3939 & 00 \end{matrix}];;$

及计算公式

并以非零元素做为子通道3的引导位置，其可表示为：and calculation formula

And use non-zero elements as the leading position of sub-channel 3, which can be expressed as:

$[\begin{matrix} 11 & 00 & 11 & 00 \end{matrix}] &CircleTimes; &CircleTimes; ((- - 128128 + + 33 \times \times 6464 + + [\begin{matrix} 1111 & 2525 & 3939 & 5353 \end{matrix}])) = = [\begin{matrix} 7575 & 00 & 103103 & 00 \end{matrix}] . .$

如此一来，本发明可决定用于一频宽为80MHz的系统的引导信号的引导位置为-103、-75、-39、-11、11、39、75及103。In this way, the present invention can determine the pilot positions of the pilot signal for a system with a bandwidth of 80 MHz to be -103, -75, -39, -11, 11, 39, 75 and 103.

值得注意的是，用于一正交频分复用(Orthogonal frequency-divisionmultiplexing，OFDM)符元的该至少一向量可不同于用于另一正交频分复用符元的其它至少一向量。换句话说，不同正交频分复用符元可定义不同向量，意即引导位置可固定或随时间变化。It should be noted that the at least one vector used for an Orthogonal frequency-division multiplexing (OFDM) symbol may be different from the other at least one vector used for another OFDM symbol. In other words, different OFDM symbols can define different vectors, which means that the guiding position can be fixed or change with time.

举例来说，请参考图6，图6为本发明实施例中一频宽为80MHz的正交频分复用系统中用于偶数正交频分复用符元及奇数正交频分复用符元的一向量表60的示意图。由图6可知，对编号为奇数的正交频分复用符元而言，子载波-103、-75、-39、-11、11、39、75及103专属用来传输引导信号，即引导频道(pilot tone)；相似地，对编号为偶数的正交频分复用符元而言，子载波-117、-89、-53、-25、25、53、89及117专属用来传输引导信号。换句话说，引导位置-103、-75、-39、-11、11、39、75及103用于奇数正交频分复用符元，而引导位置-117、-89、-53、-25、25、53、89及117用于偶数正交频分复用符元。如此一来，由于用于偶数正交频分复用符元及奇数正交频分复用符元的引导位置不同，因此本发明可仅于各正交频分复用符元中使用8个引导信号进行通道估计，即可达到使用16个引导信号进行通道估计的效果，。For example, please refer to FIG. 6 . FIG. 6 shows an even-numbered OFDM symbol and an odd-numbered OFDM in an OFDM system with a bandwidth of 80 MHz in an embodiment of the present invention. A schematic diagram of a vector table 60 of symbols. It can be seen from FIG. 6 that for OFDM symbols with odd numbers, subcarriers -103, -75, -39, -11, 11, 39, 75 and 103 are exclusively used to transmit pilot signals, namely Pilot tone; similarly, for even-numbered OFDM symbols, subcarriers -117, -89, -53, -25, 25, 53, 89, and 117 are dedicated to Transmit pilot signal. In other words, pilot positions -103, -75, -39, -11, 11, 39, 75, and 103 are used for odd OFDM symbols, while pilot positions -117, -89, -53, - 25, 25, 53, 89 and 117 are used for even OFDM symbols. In this way, since the leading positions for even OFDM symbols and odd OFDM symbols are different, the present invention can only use 8 OFDM symbols in each OFDM symbol. Channel estimation is performed on the pilot signals, and the effect of channel estimation using 16 pilot signals can be achieved.

另一方面，为了使接收器更精确进行通道估计，用于不同正交频分复用符元中一空间时间束上子载波的引导值序列优选为彼此正交，用于正交频分复用符元中一空间时间束上不同子载波的引导值序列亦优选为彼此正交，且用于正交频分复用符元中不同空间时间束上子载波的引导值序列亦优选为彼此正交。On the other hand, in order for the receiver to perform channel estimation more accurately, the pilot value sequences used for subcarriers on a space-time beam in different OFDM symbols are preferably orthogonal to each other, for OFDM The pilot value sequences of different subcarriers on a space time beam in a symbol are also preferably orthogonal to each other, and the pilot value sequences used for subcarriers on different space time beams in an OFDM symbol are also preferably mutually orthogonal Orthogonal.

请参考图7，图7为本发明实施例一引导值决定流程70的示意图。引导值决定流程70用来决定无线通信系统中引导信号的引导值。引导值决定流程70包含以下步骤：Please refer to FIG. 7 , which is a schematic diagram of a guiding value determination process 70 according to an embodiment of the present invention. The pilot value determination process 70 is used to determine the pilot value of the pilot signal in the wireless communication system. The bootstrap value determination process 70 includes the following steps:

步骤700：开始。Step 700: start.

步骤702：产生多个彼此正交的序列，各序列包含有多个元素。Step 702: Generate multiple mutually orthogonal sequences, each sequence contains multiple elements.

步骤704：分别分配该多个序列中一个不同序列予该多个引导信号中各引导信号。Step 704: Assign a different sequence of the plurality of sequences to each of the plurality of pilot signals respectively.

步骤706：以一第一特定顺序分配该一个不同序列的多个元素做为该多个引导信号中各引导信号的引导值。Step 706: Allocate elements of the one different sequence in a first specific order as pilot values of each pilot signal of the plurality of pilot signals.

步骤708：结束。Step 708: end.

由于一个空间时间束中有L个引导信号，根据引导值决定流程70，本发明产生L×N_STS个彼此正交的序列，其中，各序列包含有U元素。接着，本发明分别分配L×N_STS个序列中一个不同序列予多个引导信号中各引导信号。最后，本发明以一第一特定顺序分配该一个不同序列的U个元素做为各引导信号的引导值，例如分配该一个不同序列中一第

个元素做为用于一第n个正交频分复用符元中该多个引导信号中各引导信号的引导值，U为各序列所包含的该多个元素的数量。如此一来，由于用于正交频分复用符元中不同空间时间束上子载波的引导值序列彼此正交，且用于正交频分复用符元中一空间时间束上不同子载波的引导值序列亦彼此正交，因此本发明可更精确地进行通道估计。Since there are L pilot signals in a space-time beam, according to the pilot value determination process 70, the present invention generates L×N _STS mutually orthogonal sequences, wherein each sequence contains U elements. Next, the present invention assigns a different sequence among the L×N _STS sequences to each of the plurality of pilot signals respectively. Finally, the present invention allocates the U elements of the different sequence in a first specific order as the pilot value of each pilot signal, for example, allocates a first element in the different sequence

elements are used as pilot values for each of the multiple pilot signals in an n th OFDM symbol, and U is the number of the multiple elements included in each sequence. In this way, since the pilot value sequences used for subcarriers on different space-time beams in an OFDM symbol are orthogonal to each other, and for different subcarriers in a space-time beam in an OFDM symbol The pilot value sequences of the carriers are also orthogonal to each other, so the present invention can perform channel estimation more accurately.

再者，请参考图8，图8为本发明实施例中一引导值决定流程80的示意图。引导值决定流程80与引导值决定流程70的差别在于引导值决定流程80可减少步骤702中所产生的序列的数量，步骤702中全部为L×N_STS×U个元素。引导值决定流程80包含有该以下步骤：Furthermore, please refer to FIG. 8 , which is a schematic diagram of a guide value determination process 80 in an embodiment of the present invention. The difference between the guiding value determining process 80 and the guiding value determining process 70 is that the guiding value determining process 80 can reduce the number of sequences generated in step 702 , which are all L×N _STS ×U elements in step 702 . The bootstrap value determination process 80 includes the following steps:

步骤800：开始。Step 800: start.

步骤802：产生一N_STS乘L矩阵Q，其中QQ^T＝I_NSTS。Step 802: Generate an N _STS by L matrix Q, where QQ ^T =I _NSTS .

步骤804：以一第二特定顺序分配N_STS乘L矩阵Q中元素做为该引导信号的引导值。Step 804: Allocate elements in the N _STS by L matrix Q as pilot values of the pilot signal in a second specific order.

步骤808：结束。Step 808: end.

根据引导值决定流程80，本发明产生一N_STS乘L矩阵Q，其中QQ^T＝I_NSTS，因此N_STS乘L矩阵Q的列与列彼此正交。换句话说，引导值决定流程80仅产生N_STS个彼此正交的序列，其中，各序列包含有L元素，即全部为N_STS×L个元素而非步骤702中全部为L×N_STS×U个元素。接着，本发明以一第二特定顺序分配N_STS乘L矩阵Q中元素做为该引导信号的引导值，例如分配N_STS乘L矩阵Q中一(i_STS，1)个元素做为用于一第n个正交频分复用符元中于一第i_STS个空间时间束上一第

个引导信号中的引导值。如此一来，由于用于正交频分复用符元中不同空间时间束上子载波的引导值序列彼此正交，且用于正交频分复用符元中一空间时间束上不同子载波的引导值序列亦彼此正交，因此本发明可更精确地进行通道估计。According to the bootstrap value determination process 80 , the present invention generates an _NSTS by L matrix Q, where QQ ^T =I _NSTS , so the columns of the _NSTS by L matrix Q are orthogonal to each other. In other words, the bootstrap value determination process 80 only generates N _STS mutually orthogonal sequences, wherein each sequence contains L elements, that is, all N _STS ×L elements instead of all L×N _STS × U elements. Next, the present invention allocates elements in the matrix Q of N _STS by L as the pilot value of the pilot signal in a second specific order, for example, allocates one (i _STS , 1) element in the matrix Q of N _STS by L as used for In an n-th OFDM symbol on an i-th _STS space-time bundle

The leading value in a leading signal. In this way, since the pilot value sequences used for subcarriers on different space-time beams in an OFDM symbol are orthogonal to each other, and for different subcarriers in a space-time beam in an OFDM symbol The pilot value sequences of the carriers are also orthogonal to each other, so the present invention can perform channel estimation more accurately.

举例来说，请参考图9，图9为本发明实施例中用于一频宽为80MHz的正交频分复用系统的一引导值矩阵Q的示意图。引导值矩阵Q根据步骤802所产生的一8乘8矩阵，意即引导值矩阵Q用于N_STS≤8且8个引导子载波情况下，且引导值矩阵Q的各列彼此正交。对使用向量表60且频宽为80MHz的正交频分复用系统而言，用于一第n个正交频分复用符元中一第i_STS个空间时间束上一第k个子载波的引导信号的引导值可表示如下：For example, please refer to FIG. 9 , which is a schematic diagram of a pilot value matrix Q used in an OFDM system with a bandwidth of 80 MHz in an embodiment of the present invention. The pilot value matrix Q is an 8 by 8 matrix generated in step 802, that is, the pilot value matrix Q is used in the case of N _STS ≤ 8 and 8 pilot subcarriers, and the columns of the pilot value matrix Q are orthogonal to each other. For an OFDM system using a vector table 60 and a bandwidth of 80MHz, for a kth subcarrier on an ith _STS space-time bundle in an nth OFDM symbol The bootstrap value of the bootstrap signal can be expressed as follows:

编号为偶数的正交频分复用符元n：Orthogonal frequency division multiplexing symbol n with an even number:

编号为奇数的正交频分复用符元n：Orthogonal frequency division multiplexing symbol n with an odd number:

其中，

表示底层或截止(floor or chop-off)运算，例如

表示模运算，而Q由引导值矩阵Q所定义。如此一来，由于用于正交频分复用符元中不同空间时间束上子载波的引导值序列彼此正交，且用于正交频分复用符元中一空间时间束上不同子载波的引导值序列亦彼此正交，因此本发明可更精确地进行通道估计。in,

Indicates a floor or chop-off operation, such as

denotes a modulo operation, and Q is defined by the matrix Q of leading values. In this way, since the pilot value sequences used for subcarriers on different space-time beams in an OFDM symbol are orthogonal to each other, and for different subcarriers in a space-time beam in an OFDM symbol The pilot value sequences of the carriers are also orthogonal to each other, so the present invention can perform channel estimation more accurately.

以用于一第3个正交频分复用符元中一第3个空间时间束上引导信号的引导值为例，引导值可通过参考引导值矩阵Q的一列R3′而得。具体而言，由于第3个正交频分复用符元是一个奇符元，因此引导信号的引导位置为-103、-75、-39、-11、11、39、75及103，而用于第3个正交频分复用符元中第3个空间时间束上第-103、-75、-39、-11、11、39、75及103个子载波的引导值分别为

即-1、-1、1、1、-1、1、-1、1，其可由图9中一虚线所示的由列R3′第4个元素开始至列R3′第3个元素结束的顺序而得。依此类推，可得到其它引导值。Taking the pilot value used for the pilot signal on a third space-time beam in a third OFDM symbol as an example, the pilot value can be obtained by referring to a column R3' of the pilot value matrix Q. Specifically, since the third OFDM symbol is an odd symbol, the pilot positions of the pilot signal are -103, -75, -39, -11, 11, 39, 75 and 103, and The guide values for the -103, -75, -39, -11, 11, 39, 75 and 103 subcarriers on the third space time beam in the third OFDM symbol are respectively

That is -1, -1, 1, 1, -1, 1, -1, 1, which can be shown by a dotted line in Figure 9 from the fourth element of column R3' to the end of the third element of column R3' In order. By analogy, other boot values can be obtained.

值得注意的是，本发明的主要精神在于产生对应于至少一子通道的至少一向量，进而据以决定引导信号的数量、引导位置及引导值。本领域技术人员当可据以进行修饰或变化，而不限于此。举例来说，无线通信系统优选为符合IEEE802.11无线局域网标准，但也可为其它有使用引导信号的无线通信系统。预设向量的元素的值间优选为各间隔一特定值，如用于符合IEEE802.11无线局域网标准的无线通信系统的预设向量[11 25 39 53]各间隔14，使得引导位置在子载波中更平均分配，进而更精确进行通道估计与减少电路复杂度。此外，引导位置可固定或如图6所示随时间变化，图6中用于偶数正交频分复用符元及奇数正交频分复用符元的引导位置不同，但也可使用其它随时间变化的机制，而不限于此。It should be noted that the main spirit of the present invention is to generate at least one vector corresponding to at least one sub-channel, and then determine the number of pilot signals, the pilot position and the pilot value accordingly. Those skilled in the art may make modifications or changes accordingly, and are not limited thereto. For example, the wireless communication system preferably conforms to the IEEE802.11 wireless local area network standard, but it can also be other wireless communication systems using pilot signals. The values of the elements of the preset vector are preferably each interval a specific value, such as each interval of 14 in the preset vector [11 25 39 53] for a wireless communication system conforming to the IEEE802.11 wireless local area network standard, so that the guiding position is in the subcarrier More evenly distributed in the channel, and then more accurate channel estimation and reduce circuit complexity. In addition, the guiding position can be fixed or change with time as shown in Figure 6. In Figure 6, the guiding positions for the even OFDM symbol and the odd OFDM symbol are different, but other Mechanisms that change over time, without limitation.

另一方面，在硬件实现方面，可以软件、固件等方式，将引导信号决定流程50及引导值决定流程70、80转换为一程序，并存储于无线通信装置的一存储器中，以指示微处理执行引导信号决定流程50及引导值决定流程70、80的步骤。此等将引导信号决定流程50及引导值决定流程70、80转换为适当程序以实现对应的设定装置，应为本领域技术人员所熟知的技艺。On the other hand, in terms of hardware implementation, the pilot signal determination process 50 and the pilot value determination process 70, 80 can be converted into a program by means of software, firmware, etc., and stored in a memory of the wireless communication device to instruct the micro-processing The steps of the pilot signal determination process 50 and the pilot value determination processes 70 and 80 are executed. Converting the pilot signal determination process 50 and the pilot value determination process 70 , 80 into appropriate programs to realize corresponding setting devices should be a skill well known to those skilled in the art.

如上所述，对于下一代无线局域网系统(如符合IEEE802.11ac标准的无线通信系统，其可将通道频宽由40MHz增加至80MHz或甚至160MHz，且可支持4个以上天线，即4个以上空间时间束)，已知技术未提供决定其引导信号的方法。相较之下，本发明除了可决定用于下一代无线局域网系统中引导信号的数量、引导位置及引导值外，也可向前相容于IEEE802.11a/g/n标准。再者，由于用于奇数正交频分复用符元与用于偶数正交频分复用符元的引导位置可不相同，因此本发明于进行通道估计时，可在各正交频分复用符元中使用较少引导信号，却达到使用较多引导信号的效果。As mentioned above, for the next-generation wireless local area network system (such as a wireless communication system conforming to the IEEE802. time beam), the known technology does not provide a method for determining its guiding signal. In contrast, the present invention can be forward compatible with IEEE802.11a/g/n standards in addition to determining the number, position and value of pilot signals used in the next generation wireless local area network system. Furthermore, since the pilot positions used for odd-numbered OFDM symbols and for even-numbered OFDM symbols may be different, the present invention can perform channel estimation in each OFDM Using fewer pilot signals in the symbols achieves the effect of using more pilot signals.

总而言之，本发明可决定用于下一代无线局域网系统中引导信号的数量、引导位置及引导值，也可在奇数正交频分复用符元与偶数正交频分复用符元使用不同引导位置，以达到更高的效能。In a word, the present invention can determine the number, position and value of pilot signals used in the next generation wireless local area network system, and can also use different pilot signals for odd-numbered OFDM symbols and even-numbered OFDM symbols. position for higher performance.

以上所述仅为本发明的优选实施例，凡依本发明权利要求书所做的均等变化与修饰，均应属本发明的涵盖范围。The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims

1. A pilot determination method for a wireless communication system utilizing multiple sub-carriers for transmission, the pilot determination method comprising:

generating at least one vector corresponding to at least one subchannel; and

a plurality of pilot signals is determined according to the at least one vector.

2. The method of claim 1, wherein the at least one vector is expressed as:

wherein s represents a s-th sub-channel of the at least one sub-channel, and i is 0, 1, 2, 3_i ^(s)＝{0，1}。

3. The method of claim 2, wherein the step of generating the at least one vector corresponding to the at least one subchannel comprises:

setting a plurality of values of the at least one vector.

4. The method of claim 2, wherein the step of determining the plurality of pilot signals according to the at least one vector comprises:

summing the values of the at least one vector as a number of pilots in a space-time beam, which can be expressed as:

5. the method of claim 2, wherein the step of determining the plurality of pilot signals according to the at least one vector comprises:

and determining a plurality of pilot positions of the plurality of pilot signals according to the at least one vector and a preset vector.

6. The method of claim 5, wherein the predetermined vector comprises a plurality of elements, and each of the plurality of values of the plurality of elements is separated by a specific value.

7. The method of claim 5, wherein the step of determining the pilot positions of the plurality of pilot signals according to the at least one vector and the predetermined vector comprises:

determining the plurality of pilot locations of the plurality of pilot signals according to an equation, which can be expressed as:

wherein,

the at least one vector is represented by a vector,

represents element-to-element multiplication, N represents the number of the plurality of subcarriers, and M represents the number of subcarriers in a subchannel and represents the predetermined vector.

8. The method of claim 7, wherein the predetermined vector is [ 11253953 ].

9. The method of claim 8, wherein the wireless communication system is a 20MHz system and the at least one vector is

10. The method of claim 8, wherein the wireless communication system is a 40MHz system and the at least one vector is

11. The method of claim 8, wherein the wireless communication system is an 80MHz system and the at least one vector is

12. The method of claim 11, wherein the plurality of guiding positions are-103, -75, -39, -11, 39, 75, and 103.

13. The method of claim 8, wherein the wireless communication system is an 80MHz system and the at least one vector is

14. The method of claim 13, wherein the plurality of guiding positions are-117, -89, -53, -25, 53, 89 and 117.

15. The method of claim 1 wherein the at least one vector for one OFDM symbol is different from at least one other vector for another OFDM symbol.

16. The method of claim 1, wherein the at least one vector is used for even OFDM symbols and is different from at least one other vector used for odd OFDM symbols.

17. The method of claim 1, wherein the determining the plurality of pilot signals according to the at least one vector comprises:

a plurality of pilot values of the plurality of pilot signals are determined.

18. The method of claim 17, wherein the step of determining the plurality of pilot signals according to the at least one vector comprises:

generating a plurality of mutually orthogonal sequences, each sequence comprising a plurality of elements;

assigning a different one of the plurality of sequences to each of the plurality of pilot signals, respectively; and

the elements of the different sequence are assigned in a first specific order as pilot values for each of the plurality of pilot signals.

19. The method of claim 17, wherein the first specific order is assigned to a first of the different sequences

Each element is used as a pilot value for each of the plurality of pilots in an nth ofdm symbol, and U is the number of the plurality of elements included in each sequence.

20. The method of claim 17, wherein the step of determining the pilot values of the plurality of pilot signals comprises:

generate an N_STSMultiplying by an L matrix; and

allocating the N in a second specific order_STSMultiplying a plurality of elements in the L matrix to be used as leading values of the plurality of leading signals;

wherein N is_STSRepresenting the number of multiple space-time beams, L representing the number of multiple pilot signals used in a space-time beam, and QQ^T＝I_NSTSQ represents the number N_STSMultiplying by the L matrix.

21. The method of claim 17, wherein the second specific order is assigning the N_STSMultiply by one (i) in L matrix_STS1) elements are used in an nth OFDM symbol in an ith symbol_STSA first in a space time beam

Pilot values in the pilot signal.

22. A wireless communication system utilizing a plurality of subcarriers for transmission, comprising:

a microprocessor; and

a memory for storing a program for instructing the microprocessor to execute the pilot signal determining method according to claim 1.