CN101227697B - Pilot frequency design method based on pilot signal assistance - Google Patents

Abstract

The invention relates to a pilot frequency design method which is based on the assistance of pilot signal. The method comprises the following steps: pilot main sequence of a district and a pilot auxiliary sequence meet a certain of phase-shift relationship, pilot matrixes of an object district and an adjacent district are designed, and the adjacent district is led to have the same pilot structure with the object district, and the matrix of the adjacent district and the matrix of the object district meet the relationship that mean square error of least square estimation value which is responded by a channel of the object district is led to be minimum, and channel response of the object district is obtained through calculating. When the invention designs the pilot matrix of the adjacent district and the pilot matrix of the object district, the pilot matrixes are requested to meet the relationship that mean square error of least square estimation value which is responded by a channel of the object district is led to be minimum, and the error of a disturbance area to the object area is led to be the minimum, and the channel model which is established inhibits the disturbance between adjacent districts in maximum.

Description

Based on the auxiliary pilot design method of pilot signal

Technical field

The present invention relates to the mobile communication technology field, relate in particular to a kind of OFDM (Orthogonal Frequency Division Multiplexing, be called for short OFDM) high-speed mobile environment pilot design method of assisting based on pilot signal down.

Background technology

Raising along with people's material and inspirit culture demand; In foreseeable future; Multimedia services such as audio frequency, video, image and the Internet will become the dominant traffic of mobile communication, and these business have very high requirement (for example requiring peak traffic speed greater than 20Mbps) to the transmission of radio links ability.The OFDM technology has obtained extensive use as a kind of broadband wireless parallel data transmission technology of resisting the decline of frequency domain selectivity; Improved the ability of OFDM symbol anti-multipath time delay; And pass through to increase protection interval (GI) greater than maximum multipath time delay at the front end of OFDM symbol; Eliminate the intersymbol interference (ISI) that causes by multidiameter delay, reduced the complexity of receiving terminal equalizer.Therefore the OFDM technology is adopted by a plurality of international standard, and is acknowledged as one of physical layer basic fundamental of back three generations (B3G) GSM.

Become fading channel when wireless channel is generally multipath, change at random can take place in each footpath amplitude and phase place in time, according to the requirement of present GSM; Portable terminal should possess the adaptive capacity from static situation to the 500km/h mobile environment; When the translational speed of portable terminal is very high, the Doppler frequency deviation of generation will be very big, and Doppler frequency deviation can cause and disturbs between subcarrier; Therefore need before the signal demodulation, carry out dynamic estimation, to recover the primary signal that transmitting terminal sends to channel.In order to overcome Doppler's deviation of wireless channel; Mainly contain two kinds of channel estimation methods in the prior art: the auxiliary and blind Channel Estimation of pilot signal; Wherein the auxiliary channel estimation method performance of pilot signal is more superior and adopted by most B3G system; For the auxiliary channel estimation method of pilot signal, the pilot tone inserted mode has multiple, for example Comb Pilot (being that pilot tone is on average placed between subcarrier), block pilot tone (being distributed in certain piece zone in the pilot set).

Yet under many co-frequency cells environment, the high-speed mobile platform of cell edge disturbs, also receive the interference of many sub-districts except between the subcarrier that receives Doppler frequency deviation and cause based on ofdm system, as shown in Figure 1, be many area interference sketch map in the prior art.Prior art still can not overcome the interference that bring many sub-districts, thus the deviation that causes signal to be estimated, and can't accurately recover primary signal.

Summary of the invention

The objective of the invention is to propose a kind of pilot design method and system of assisting based on pilot signal, can under many co-frequency cells environment, overcome the interference that neighbor cell brings.

For realizing above-mentioned purpose, the invention provides the auxiliary pilot design method of a kind of pilot signal, may further comprise the steps:

Pilot matrix to Target cell and neighbor cell designs; Make neighbor cell have the pilot configuration identical with said Target cell; And satisfy the minimum relation of mean square error of the least-squares estimation value of the channel response that makes Target cell between the pilot matrix of said neighbor cell and the pilot matrix of Target cell, calculate the channel response that obtains Target cell.

In technique scheme; Because Target cell adopts identical pilot configuration with interfered cell; And satisfy the minimum relation of mean square error of the least-squares estimation value of the channel response that makes Target cell between the pilot tone chief series of Target cell and neighbor cell, can on to greatest extent, suppress the interference of neighbor cell Target cell with this channel model of setting up.

Further, the step that the pilot matrix of Target cell and neighbor cell is designed comprises:

The pilot tone chief series of target setting sub-district and neighbor cell is so that satisfy the minimum relation of mean square error of the least-squares estimation value of the channel response that makes Target cell between the pilot tone chief series of the pilot tone chief series of said Target cell and neighbor cell;

Pilot tone chief series to said Target cell and neighbor cell carries out phase-shift operations, comes to set respectively the auxilliary sequence of pilot tone of said Target cell and neighbor cell;

Through to the pilot tone chief series of said Target cell and the auxilliary sequence of pilot tone, and the pilot tone chief series of neighbor cell carries out Fourier transform with the auxilliary sequence of pilot tone, distinguishes the pilot matrix of target setting sub-district and neighbor cell.

Auxilliary sequence of the pilot tone chief series of Target cell and neighbor cell, pilot tone and pilot matrix all can be in the Theoretical Calculation before the channel estimating be calculated by the pilot tone chief series of Target cell and are obtained; So just make the auxilliary sequence of pilot tone chief series, pilot tone and the pilot matrix of each sub-district all satisfy certain relation, make the correlation of minizone pilot tone reduce as far as possible.

Further, before the auxilliary sequence of pilot tone chief series, pilot tone of target setting sub-district, also comprise the operation of setting pilot tone bunch number S and normalization Doppler frequency deviation Q.Wherein a pilot tone bunch number S selects according to system design, and general pilot tone bunch number S be 2 a positive integer time power greater than the minimum of normalization maximum multipath time delay L, can be divided exactly by the total N of subcarrier to guarantee S.Normalization Doppler frequency deviation Q ask for formula can for

T is the time that the OFDM symbol is removed Cyclic Prefix, f _MaxBe maximum Doppler frequency offset.

Further, the operation of the pilot tone chief series of said target setting sub-district, the auxilliary sequence of pilot tone and pilot matrix is specially:

Obtain the sequence number γ (p) of the pilot tone chief series place subcarrier of Target cell according to said pilot tone bunch number S, and according to the pilot tone chief series X that generates said Target cell corresponding to the permanent amplitude zero auto-correlation sign indicating number (CAZAC) of said sequence number γ (p) _Q/2, wherein

X _Q/2＝[X(γ(0))，X(γ(1))，…，X(γ(S-1))] ^T；

$\mathrm{\&gamma;}\left(p\right)=a_0+\frac{N}{S}p,p=0,...,$ S-1, a ₀Be positive integer, and $\frac{\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">Q</figure-callout>}}{2}\&le;a_0\&le;S-1;$

Wherein, a ₀The expression side-play amount;

According to the pilot tone chief series X of said normalization Doppler frequency deviation Q to said Target cell _Q/2Carry out phase shift, generate the auxilliary sequence X of pilot tone of Target cell _q, wherein

$X_q={[X\left(k_q^{\mathrm{\&gamma;}\left(0\right)}\right),...,X\left(k_q^{\mathrm{\&gamma;}(S-1)}\right)]}^T,$ q＝0，…，Q， $q\&NotEqual;\frac{\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">Q</figure-callout>}}{2},$

$X\left(k_q^{\mathrm{\&gamma;}\left(p\right)}\right)=X\left(\mathrm{\&gamma;}\left(p\right)\right)\exp (\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}{a}_0\mathrm{\&gamma;}\left(p\right)(q-\frac{Q}{2})L/N)),$ p＝0，…，S-1，

$k_q^{\mathrm{\&gamma;}(k-1)}=(\mathrm{\&gamma;}(k-1)-q+Q/2)\mathrm{mod}N,$ k＝0，…，S-1

Wherein, L representes the normalization maximum multipath time delay, and N representes total number of sub-carriers;

Through pilot tone chief series X to said Target cell _Q/2With the auxilliary sequence X of pilot tone _qCarry out Fourier transform, obtain the pilot matrix P of Target cell, wherein

$P=[\mathrm{diag}\left(X_0\right){\stackrel{\&OverBar;}{F}}_0,...,\mathrm{diag}\left(X_Q\right){\stackrel{\&OverBar;}{F}}_Q],$

Be S * L matrix, k capable vector be [1 ..., exp (j2 π k _q ^{γ (k-1)}(L-1)/N)],

$k_q^{\mathrm{\&gamma;}(k-1)}=(\mathrm{\&gamma;}(k-1)-q+Q/2)\mathrm{mod}N,$ k＝0，…，S-1。

Further, the operation of the pilot tone chief series of said setting neighbor cell, the auxilliary sequence of pilot tone and pilot matrix is specially:

When the pilot tone main sequence of target setting sub-district is classified the CAZAC sequence as, through pilot tone chief series X to said Target cell _Q/2The side-play amount of carrying out with said cyclic shift is the cyclic shift of unknown quantity, obtains the pilot tone chief series X of neighbor cell _Q/2 ¹, wherein

$X_{Q/2}^1={[X^1\left({\mathrm{\&gamma;}}^1\left(0\right)\right),X^1\left({\mathrm{\&gamma;}}^1\left(1\right)\right),...,X^1\left({\mathrm{\&gamma;}}^1(S-1)\right)]}^T$

According to the pilot tone chief series X of said normalization Doppler frequency deviation Q to said neighbor cell _Q/2 ¹Carry out phase shift, generate the auxilliary sequence X of pilot tone of neighbor cell _q ¹, wherein

$X_q^1={[X^1\left(k_q^{\mathrm{\&gamma;}\left(0\right)}\right),...,X^1\left(k_q^{\mathrm{\&gamma;}(S-1)}\right)]}^T,$ q＝0，…，Q， $q\&NotEqual;\frac{\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">Q</figure-callout>}}{2},$

$X^1\left(k_q^{\mathrm{\&gamma;}\left(p\right)}\right)=X^1\left(\mathrm{\&gamma;}\left(p\right)\right)\exp (\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}{a}_0\mathrm{\&gamma;}\left(p\right)(q-\frac{Q}{2})L/N)),$ p＝0，…，S-1。

Through pilot tone chief series X to said neighbor cell _Q/2 ¹With the auxilliary sequence X of pilot tone _q ¹Carry out Fourier transform, set the pilot matrix P of neighbor cell ¹, wherein

The pilot matrix P of neighbor cell ¹Obtain through following formula,

$P^1=[\mathrm{diag}\left(X_0^1\right){\stackrel{\&OverBar;}{F}}_0^1,...,\mathrm{diag}\left(X_Q^1\right){\stackrel{\&OverBar;}{F}}_Q^1],$

Be S * L matrix, k capable vector be [1 ..., exp (j2 π k _q ^{γ (k-1)}(L-1)/N)],

$k_q^{\mathrm{\&gamma;}(k-1)}=(\mathrm{\&gamma;}(k-1)-q+Q/2)\mathrm{mod}N,$ k＝0，…，S-1。

Further, the least-squares estimation value of the channel response of Target cell

is found the solution by following formula:

$\stackrel{\&OverBar;}{Y}=\mathrm{Ph}+P^1{h}^1+\stackrel{\&OverBar;}{W};$

$\hat{h}={\left(P^{H}P\right)}^{-1}{P}^H\stackrel{\&OverBar;}{Y}=h+{\left(P^{H}P\right)}^{-1}{P}^H{P}^1{h}^1+{\left(P^{H}P\right)}^{-1}{P}^H\stackrel{\&OverBar;}{W};$

Wherein,

The pilot tone place signal that the expression receiving terminal receives;

Expression additive white Gaussian noise vector, h, h ¹The channel response of representing Target cell and neighbor cell respectively;

The formula of the mean square error of the least-squares estimation value of the estimated value of the channel response of said Target cell does

$\mathrm{MSE}=\frac{1}{(Q+1)L}E\left[{\left|\right|\hat{h}-h\left|\right|}^2\right]=\frac{1}{(Q+1)L}E\left[\right||{\left(P^{H}P\right)}^{-1}{P}^H{P}^1{h}^1+{\left(P^{H}P\right)}^{-1}{P}^H\stackrel{\&OverBar;}{W}|\left|\right],$

Wherein

expression additive white Gaussian noise is vectorial; E representes mathematic expectaion, and ‖ ‖ representes norm.

Further, said through the pilot matrix of Target cell and neighbor cell is calculated, the operation that obtains the channel response of Target cell is specially:

The channel response estimated value of Target cell obtains through following formula,

$\hat{h}={\left(P^{H}P\right)}^{-1}{P}^H\stackrel{\&OverBar;}{Y};$

Wherein,

representes the pilot tone place signal that receiving terminal receives.

Based on technique scheme; When the present invention designs in the pilot matrix to the pilot matrix of neighbor cell and Target cell; Satisfy the minimum relation of mean square error of the least-squares estimation value of the channel response that makes Target cell between the requirement pilot matrix; So that interfered cell is minimum to the error that Target cell causes, on to greatest extent, suppressed interference among adjacent cells with this channel model of setting up.

Description of drawings

Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, do not constitute improper qualification of the present invention.In the accompanying drawings:

Fig. 1 is many area interference sketch map in the prior art.

Fig. 2 is the sketch map that the present invention is based on pilot configuration in the auxiliary pilot design method of pilot signal.

Fig. 3 is the schematic flow sheet that the present invention is based on an embodiment of the auxiliary pilot design method of pilot signal.

Fig. 4 is the schematic flow sheet that the present invention is based on another embodiment of the auxiliary pilot design method of pilot signal.

Embodiment

Through accompanying drawing and embodiment, technical scheme of the present invention is done further detailed description below.

The present invention is directed under many co-frequency cells environment, carry out signal for the high-speed mobile platform of cell edge and estimate, and suppressed the interference of neighbor cell the Target cell signal.

As shown in Figure 3, be the schematic flow sheet of the embodiment that the present invention is based on the auxiliary pilot design method of pilot signal.In the present embodiment, mainly may further comprise the steps:

Step 101, the pilot matrix of Target cell and neighbor cell is designed; Make neighbor cell have the pilot configuration identical with said Target cell; And satisfy the minimum relation of mean square error of the least-squares estimation value of the channel response that makes Target cell between the pilot matrix of said neighbor cell and the pilot matrix of Target cell, and calculate the channel response that obtains Target cell.

Pilot configuration is as shown in Figure 2, has enumerated two subcarriers among the figure, and wherein diagonal line hatches representes that pilot tone assists sequence, thin grid shadow representation pilot tone chief series, and blank space is represented data subcarrier or unloaded ripple.

In the present embodiment; Target cell adopts identical pilot configuration with neighbor cell; And having between the pilot matrix of Target cell and neighbor cell can be so that the minimum relation of the mean square error of the least-squares estimation value of the channel response of Target cell, that is to say through the suitable cyclic shift amount of the pilot matrix of target setting sub-district and neighbor cell to make the interference minimum that neighbor cell causes Target cell.

As shown in Figure 4, be the schematic flow sheet of another embodiment of the present invention is based on the auxiliary pilot design method of pilot signal.Compare with a last embodiment, present embodiment has also comprised the step of pilot design, and the step of pilot design comprises:

The pilot tone chief series of step 201, target setting sub-district and each neighbor cell is so that satisfy the minimum relation of mean square error of the least-squares estimation value of the channel response that makes Target cell between the pilot tone chief series of the pilot tone chief series of said Target cell and neighbor cell;

Step 202, the pilot tone chief series of said Target cell and neighbor cell is carried out phase-shift operations, come to set respectively the auxilliary sequence of pilot tone of said Target cell and neighbor cell;

Step 203, through to the pilot tone chief series of said Target cell and the auxilliary sequence of pilot tone, and the pilot tone chief series of neighbor cell carries out Fourier transform with the auxilliary sequence of pilot tone, distinguishes the pilot matrix of target setting sub-district and neighbor cell.

In the present embodiment, in time, becomes the OFDM channel model and can adopt the BEM channel to represent,

$h(n;l)=\underset{q=0}{\overset{Q}{\mathrm{\&Sigma;}}}{h}_q\left(l\right){\mathrm{<figure-callout\; id="2"\; label="e\; j"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">e</figure-callout>}}^j,l=0,...L-1,$

Wherein, Q is the normalization Doppler frequency deviation, f _MaxBe maximum Doppler frequency offset; L is the normalization maximum multipath time delay, h _qBe the multiple Gaussian random variable of zero-mean, N is the ofdm system total number of sub-carriers, also representes to remove in the OFDM symbol simultaneously section number effective time of Cyclic Prefix.

Pilot tone bunch number S and normalization Doppler frequency deviation Q can calculate before the pilot tone chief series of confirming Target cell, the auxilliary sequence of pilot tone and pilot matrix, also can set in advance.Wherein a pilot tone bunch number S selects according to system design, and general pilot tone bunch number S be 2 a positive integer time power greater than the minimum of normalization maximum multipath time delay L, can be divided exactly by the total N of subcarrier to guarantee S.Normalization Doppler frequency deviation Q asks for formula and can be

At the pilot tone chief series of target setting sub-district, when pilot tone is assisted sequence and pilot matrix, generally select the sequence that can make pilot tone chief series and the auxilliary sequence of pilot tone satisfy the phase shift relation for use.Here be example with permanent amplitude zero auto-correlation sign indicating number (CAZAC) sequence; At the pilot tone chief series of target setting sub-district, when pilot tone is assisted sequence and pilot matrix; Can obtain the sequence number γ (p) of the pilot tone chief series place subcarrier of Target cell according to said pilot tone bunch number S, and generate the pilot tone chief series X of said Target cell according to CAZAC sequence corresponding to said sequence number γ (p) _Q/2, wherein

X _Q/2＝[X(γ(0))，X(γ(1))，…，X(γ(S-1))] ^T；

$\mathrm{\&gamma;}\left(p\right)=a_0+\frac{N}{S}p,p=0,...,S-1,$ a ₀Be positive integer, and $\frac{\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">Q</figure-callout>}}{2}\&le;a_0\&le;S-1;$

Wherein, a ₀Represent the side-play amount of a last subcarrier to the pilot tone chief series of current subcarrier;

According to the pilot tone chief series X of said normalization Doppler frequency deviation Q to said Target cell _Q/2Carry out phase shift, generate the auxilliary sequence X of pilot tone of Target cell _q, wherein

$X_q={[X\left(k_q^{\mathrm{\&gamma;}\left(0\right)}\right),...,X\left(k_q^{\mathrm{\&gamma;}(S-1)}\right)]}^T,$ q＝0，…，Q， $q\&NotEqual;\frac{\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">Q</figure-callout>}}{2},$

$X\left(k_q^{\mathrm{\&gamma;}\left(p\right)}\right)=X\left(\mathrm{\&gamma;}\left(p\right)\right)\exp (\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}{a}_0\mathrm{\&gamma;}\left(p\right)(q-\frac{Q}{2})L/N),$ p＝0，…，S-1，

$k_q^{\mathrm{\&gamma;}(k-1)}=(\mathrm{\&gamma;}(k-1)-q+Q/2)\mathrm{mod}N,$ k＝0，…，S-1；

Wherein, L representes the normalization maximum multipath time delay, and N representes total number of sub-carriers;

Through pilot tone chief series X to said Target cell _Q/2With the auxilliary sequence X of pilot tone _qCarry out Fourier transform, obtain the pilot matrix P of Target cell, wherein

$P=[\mathrm{diag}\left(X_0\right){\stackrel{\&OverBar;}{F}}_0,...,\mathrm{diag}\left(X_Q\right){\stackrel{\&OverBar;}{F}}_Q],$

Be S * L matrix, k capable vector be [1 ..., exp (j2 π k _q ^{γ (k-1)}(L-1)/N)],

$k_q^{\mathrm{\&gamma;}(k-1)}=(\mathrm{\&gamma;}(k-1)-q+Q/2)\mathrm{mod}N,$ k＝0，…，S-1。

Wherein the CAZAC sequence can be expressed as c _k(i)=exp (j π ki ²/ S), i=0 ..., S-1 it should be noted and selects for use the CAZAC sequence just to be used for illustrating as the pilot tone chief series, is not the qualification as the pilot tone chief series, as long as the dominant pilot sequence all can with the sequence of teaching frequency sequence to satisfy corresponding phase relation.

Behind the pilot tone chief series of target setting sub-district, based on principle, through pilot tone chief series X to said Target cell with pilot configuration _Q/2The side-play amount of carrying out with said cyclic shift is the cyclic shift of unknown quantity, obtains the pilot tone chief series X of neighbor cell _Q/2 ¹,

Be sequence c _k((p-c ₀) modS)=exp (j π k ((p-c ₀) modS) ²/ S), p=0 ..., S-1

Wherein, c ₀The side-play amount of expression cyclic shift is as the unknown quantity that need find the solution in the pilot design;

According to the pilot tone chief series X of said normalization Doppler frequency deviation Q to said neighbor cell _Q/2 ¹Carry out phase shift, generate the auxilliary sequence X of pilot tone of neighbor cell _q ¹, wherein

$X_q^1={[X^1\left(k_q^{\mathrm{\&gamma;}\left(0\right)}\right),...,X^1\left(k_q^{\mathrm{\&gamma;}(S-1)}\right)]}^T,$ q＝0，…，Q， $q\&NotEqual;\frac{\mathrm{<figure-callout\; id="2"\; label="Q"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">Q</figure-callout>}}{2},$

$X^1\left(k_q^{\mathrm{\&gamma;}\left(p\right)}\right)=X^1\left(\mathrm{\&gamma;}\left(p\right)\right)\exp (\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100568743E00011.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}{a}_0\mathrm{\&gamma;}\left(p\right)(q-\frac{Q}{2})L/N)),$ p＝0，…，S-1。

Through pilot tone chief series X to said neighbor cell _Q/2With the auxilliary sequence X of pilot tone _qCarry out Fourier transform, obtain the pilot matrix of neighbor cell, wherein the pilot matrix P of neighbor cell ¹Obtain through following formula,

$P^1=[\mathrm{diag}\left(X_0^1\right){\stackrel{\&OverBar;}{F}}_0^1,...,\mathrm{diag}\left(X_Q^1\right){\stackrel{\&OverBar;}{F}}_Q^1],$

Be S * L matrix, k capable vector be [1 ..., exp (j2 π k _q ^{γ (k-1)}(L-1)/N)],

$k_q^{\mathrm{\&gamma;}(k-1)}=(\mathrm{\&gamma;}(k-1)-q+Q/2)\mathrm{mod}N,k=0,...,S-1.$

The channel response estimated value of Target cell obtains through following formula:

$\hat{h}={\left(P^{H}P\right)}^{-1}{P}^H\stackrel{\&OverBar;}{Y}$

In pilot design, for the pilot tone chief series that adopts the CAZAC sequence, the mean square error minimum of the least-squares estimation value of the channel response at pilot tone place that can be through asking for Target cell obtains side-play amount c ₀, the least-squares estimation value of channel response obtains through following formula,

$\stackrel{\&OverBar;}{Y}=\mathrm{Ph}+P^1{h}^1+\stackrel{\&OverBar;}{W};$

$\hat{h}={\left(P^{H}P\right)}^{-1}{P}^H\stackrel{\&OverBar;}{Y}=h+{\left(P^{H}P\right)}^{-1}{P}^H{P}^1{h}^1+{\left(P^{H}P\right)}^{-1}{P}^H\stackrel{\&OverBar;}{W};$

Wherein,

The pilot tone place signal that the expression receiving terminal receives,

Expression additive white Gaussian noise vector, h, h ¹The channel estimating of representing Target cell and neighbor cell respectively.

Next through the mean square error computing formula of following least-squares estimation value, confirm the side-play amount c of cyclic shift between the pilot matrix of pilot matrix and Target cell of said neighbor cell ₀,

$\mathrm{MSE}=\frac{1}{(Q+1)L}E\left[{\left|\right|\hat{h}-h\left|\right|}^2\right]=\frac{1}{(Q+1)L}E\left[\right||{\left(P^{H}P\right)}^{-1}{P}^H{P}^1{h}^1+{\left(P^{H}P\right)}^{-1}{P}^H\stackrel{\&OverBar;}{W}|\left|\right]$

Wherein

Expression additive white Gaussian noise vector, E representes mathematic expectaion, ‖ ‖ representes norm, tries to achieve the side-play amount c that makes the minimum cyclic shift of MSE ₀

The side-play amount c of cyclic shift ₀Constitute the important relationship between Target cell and the neighbor cell, select to make the side-play amount c of the minimum cyclic shift of MSE ₀Can eliminate the interference that neighbor cell brings Target cell.For the situation of pilot tone chief series employing CAZAC sequence, be applicable to the side-play amount c of the cyclic shift between the pilot tone chief series of finding the solution Target cell and neighbor cell ₀, and adopt the situation of other sequences, the side-play amount c that is not limited to find the solution cyclic shift for the pilot tone chief series ₀And only need meet the following conditions: neighbor cell has the pilot configuration identical with Target cell, and satisfies the minimum relation of mean square error of the least-squares estimation value of the channel response that makes Target cell between the pilot matrix of the pilot matrix of said neighbor cell and Target cell.

The present invention both had been applicable to the situation of many antennas, also was applicable to the situation of single antenna.

One of ordinary skill in the art will appreciate that: the data that relate in all or part of step of realization said method embodiment and the step all can be accomplished through the relevant hardware of program command; Aforesaid program and data can be stored in the computer read/write memory medium; This program the step that comprises said method embodiment when carrying out; And aforesaid storage medium comprises: various media that can be program code stored such as ROM, RAM, magnetic disc or CD.

Should be noted that at last: above embodiment is only in order to technical scheme of the present invention to be described but not to its restriction; Although with reference to preferred embodiment the present invention has been carried out detailed explanation, the those of ordinary skill in affiliated field is to be understood that: still can specific embodiments of the invention make amendment or the part technical characterictic is equal to replacement; And not breaking away from the spirit of technical scheme of the present invention, it all should be encompassed in the middle of the technical scheme scope that the present invention asks for protection.

Claims (4)

1. one kind based on the auxiliary pilot design method of pilot signal; May further comprise the steps: the pilot matrix to Target cell and neighbor cell designs; Make neighbor cell have the pilot configuration identical with said Target cell; And satisfy the minimum relation of mean square error of the least-squares estimation value of the channel response that makes Target cell between the pilot matrix of said neighbor cell and the pilot matrix of Target cell, and calculate the channel response that obtains Target cell;

The wherein said step that the pilot matrix of Target cell and neighbor cell is designed comprises:

The pilot tone chief series of target setting sub-district and neighbor cell is so that satisfy the minimum relation of mean square error of the least-squares estimation value of the channel response that makes Target cell between the pilot tone chief series of the pilot tone chief series of said Target cell and neighbor cell;

Pilot tone chief series to said Target cell and neighbor cell carries out phase-shift operations, comes to set respectively the auxilliary sequence of pilot tone of said Target cell and neighbor cell;

Through to the pilot tone chief series of said Target cell and the auxilliary sequence of pilot tone, and the pilot tone chief series of neighbor cell carries out Fourier transform with the auxilliary sequence of pilot tone, distinguishes the pilot matrix of target setting sub-district and neighbor cell.

2. pilot design method according to claim 1 wherein before the auxilliary sequence of pilot tone chief series, pilot tone of target setting sub-district, also comprises the operation of setting pilot tone bunch number S and normalization Doppler frequency deviation Q.

3. pilot design method according to claim 2, the operation of the pilot tone chief series of wherein said target setting sub-district, the auxilliary sequence of pilot tone and pilot matrix is specially:

Obtain the sequence number γ (p) of the pilot tone chief series place subcarrier of Target cell according to said pilot tone bunch number S, and according to the pilot tone chief series X that generates said Target cell corresponding to the permanent amplitude zero auto-correlation sign indicating number of said sequence number γ (p) _Q/2

According to the pilot tone chief series X of said normalization Doppler frequency deviation Q to said Target cell _Q/2Carry out phase shift, generate the auxilliary sequence X of pilot tone of Target cell _q

Through pilot tone chief series X to said Target cell _Q/2With the auxilliary sequence X of pilot tone _qCarry out Fourier transform, obtain the pilot matrix P of Target cell.

4. pilot design method according to claim 3, the operation of the pilot tone chief series of wherein said setting neighbor cell, the auxilliary sequence of pilot tone and pilot matrix is specially:

Through pilot tone chief series X to said Target cell _Q/2Carry out cyclic shift, obtain the pilot tone chief series of neighbor cell

According to said normalization Doppler frequency deviation Q the pilot tone chief series

of said neighbor cell is carried out phase shift, generate the auxilliary sequence of pilot tone of neighbor cell

Through pilot tone chief series to said neighbor cell With the auxilliary sequence of pilot tone

Carry out Fourier transform, set the pilot matrix P of neighbor cell ¹

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