CN101729486A - Method and system for double-antenna receiving diversity in single carrier frequency domain equalization system - Google Patents

Abstract

The invention discloses a method and a system for double-antenna receiving diversity in a single carrier frequency domain equalization system. The method comprises the following steps: synchronously processing receiving signals of two receiving antennas; performing channel estimation for the synchronized receiving signals to acquire frequency domain responses H1 and H2 and simultaneously acquire noise estimation values sigma 12 and sigma 22 of the receiving signals; when the noise estimation value sigma 12 or sigma 22 is greater than the preset threshold value K, calculating an equalization coefficient by adopting a lowest estimation noise criterion, and performing equalization; and when both the noise estimation values sigma 12 and sigma 22 are not greater than the threshold value K, calculating the equalization coefficient by adopting a maximum merging criterion, and performing equalization. By adopting different criterions to calculate the equalization coefficient so as to perform the equalization process aiming at different conditions, the defect of performance deterioration possibly caused by diversity technology based on the maximum merging criterion under the condition of deep decline is avoided, and the best diversity grain also can be acquired even if one receiving antenna cannot synchronize normally.

Description

Double-antenna receiving diversity method and system in a kind of single-carrier frequency domain equalization system

Technical field

The present invention relates to the single-carrier wave frequency domain equalization technology field, particularly relate to a kind of based on double-antenna receiving diversity method and system in the adaptive single-carrier frequency domain equalization system of Noise Estimation.

Background technology

In wireless communication system, except being subjected to various interference of noise, the multipath transmisstion that transmits also affects transfer of data.Along with the raising of signal transmission rate, more and more higher transmission bandwidth has caused serious time dispersive, has comprised the multipath ripple of experience decay and time delay in the received signal, causes frequency selective fading, thereby causes problems such as serious intersymbol interference and deep fade.Single-carrier frequency domain equalization system (SC-FDE, Single Carrier-Frequency Domain Equalization) is a kind of effectively method that anti-multipath is disturbed in the broadband wireless transmission, can address the above problem preferably.

The SC-FDE Technology Need inserts the Cyclic Prefix line frequency territory equilibrium of going forward side by side, and this method sends signal with the symbolic blocks structure simultaneously, and receiving terminal is required height synchronously, and is quite responsive to frequency departure.General SC-FDE system data transmits frame by frame, and every frame is made up of n data block and 1 leader block, as shown in Figure 1.

Multi-antenna technology is the important channel that mobile communication system improves signal transmission quality, is one of important breakthrough in the modern communication technology, and antagonism deep fade most effectual way is utilized multi-antenna technology exactly.Many antennas reception technique is exactly that a plurality of antennas by receiving terminal carry out signal and receive, thereby improves the signal transmission quality of receiving terminal.For the single antenna receiving system, owing to the time-varying characteristics of wireless channel, the situation of deep fade will inevitably appear constantly at some, and the energy that arrive receiving terminal this moment is very low, influences signal transfer quality.And the double antenna reception technique utilizes two antennas received signal simultaneously, and the possibility that receives the deep fade signal simultaneously owing to two antennas is significantly less than individual antenna, has so just introduced diversity gain.

In the SC-FDE system, general many antennas receive and all adopt double antenna to receive.The double antenna receiving system mainly comprises synchronization module, channel estimation module, frequency domain equalization module.Only obtain just carrying out channel estimating synchronously accurately, and then carry out frequency domain equalization.The method of double-antenna receiving diversity is mainly at the frequency domain equalization module, general SC-FDE system all adopts maximum merging criterion, as shown in Figure 2, the transmission signal is x, and two antennas receive signal r1, r2 respectively sometime, after carrying out synchronously separately, carry out channel estimating respectively and obtain H1, H2, the H1 that obtains, H2 enter the frequency domain equalization module simultaneously and calculate equalizing coefficient and carry out equilibrium treatment according to maximum merging criterion.

For double-antenna receiving diversity method in the single-carrier frequency domain equalization system that adopts maximum merging criterion, to guarantee that at first the receiving terminal self of each antenna has been finished synchronous accurately---regularly synchronous and carrier synchronization.But owing to there is the deep fade situation, the received signal energy that certain antenna receiving terminal will occur is very low, can't finish correct synchronously, the complete mistake of channel estimation results that causes this antenna receiving terminal, utilize this moment maximum merging criterion to calculate equalizing coefficient and carry out equilibrium again, can worsen data transmission quality on the contrary, reduce the reliability of receiver.Therefore maximum merging criterion is to be based upon on the entirely true synchronous basis of the receiving terminal of each antenna.

Summary of the invention

The invention provides a kind of based on double-antenna receiving diversity method and system in the adaptive single-carrier frequency domain equalization system of Noise Estimation, in order to solve exist in the prior art when the signal deep fade, adopt that the double-antenna receiving diversity method can worsen the data transmission quality problem in the single-carrier frequency domain equalization system of maximum merging criterion.

For reaching above-mentioned purpose, on the one hand, the invention provides double-antenna receiving diversity method in a kind of single-carrier frequency domain equalization system, said method comprising the steps of:

Received signal to two reception antennas is carried out Synchronous Processing;

Received signal is synchronously carried out channel estimating, obtain frequency domain response H ₁, H ₂, and obtain the noise estimation values sigma of described received signal simultaneously ₁ ², σ ₂ ²

When described noise estimation values sigma ₁ ²Or σ ₂ ²During greater than preset threshold value K, adopt minimum estimating noise criterion to calculate equalizing coefficient, and carry out equilibrium; When described noise estimation values sigma ₁ ²And σ ₂ ²When all being not more than described threshold k, adopting maximum merging criterion to calculate equalizing coefficient, and carry out equilibrium.

Further, the leader block sequence that the transmitting terminal of sending signal for two described reception antennas is used for channel estimating is the UW sequence, u=[u (1) ..., u (M)], its Fourier changing value is U _Fft=[U (1) ... U (M)].

Further, to before the received signal after is synchronously carried out channel estimating, also comprise:

From described received signal, extract the pilot data that is used for channel estimating (i=1,2); Wherein, the pilot data length overall is 2M, is made up of the UW data of two M length, and i represents the numbering of antenna.

Further, obtain frequency domain response H ₁, H ₂And noise estimation values sigma ₁ ², σ ₂ ², the tool bag is drawn together following steps:

To pilot data

Carry out fast Fourier transform, obtain

Obtain pilot data

Frequency domain information;

Obtain the noise estimation value of each reception antenna received signal by following formula:

${{\mathrm{\σ}}_1}^2=\frac{{\left|R_1\left(2\right)\right|}^2+{\left|R_1\left(4\right)\right|}^2+\·\·\·+{\left|R_1\left(M\right)\right|}^2}{2M};$

${{\mathrm{\σ}}_2}^2=\frac{{\left|R_2\left(2\right)\right|}^2+{\left|R_2\left(4\right)\right|}^2+\·\·\·+{\left|R_2\left(M\right)\right|}^2}{2M};$

Obtain frequency domain response H by following formula ₁, H ₂:

$H_1=[h_1\left(1\right),...,h_1\left(M\right)]=\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{R}_1(2n-1)/U\left(n\right);$

$H_2=[h_2\left(1\right),...,h_2\left(M\right)]=\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{R}_2(2n-1)/U\left(n\right);$

Wherein, R ₁(2), R ₁(4) ..., R ₁(M) be vector : the value of lining; R ₂(2), R ₂(4) ..., R ₂(M) be vector

In value; U (n) is vectorial U _FftIn value.

Further, adopt maximum merging criterion to calculate equalizing coefficient, and carry out equilibrium, specifically comprise:

Obtain the equalizing coefficient W of each reception antenna correspondence by following formula _i:

$W_i=[W_i\left(1\right),W_i\left(2\right),...,W_i\left(M\right)]=\frac{H_i^{*}}{{\left|H_1\right|}^2+{\left|H_2\right|}^2+{{\mathrm{\σ}}_1}^2};$

Obtain equalizing coefficient W _iAfter, carry out equilibrium treatment by following equalization algorithm formula:

Z(k)＝W ₁(k)·R ₁(k)+W ₂(k)·R ₂(k)；

Wherein, H _i ^*Be vectorial H _iConjugation; | H _i| be vectorial H _iMould; I is the numbering of antenna, (i=1,2); K=1 ..., M; R ₁(k), R ₂(k) be vector respectively In value; W ₁(k), W ₂(k) be vectorial W respectively ₁, W ₂In value.

Further, adopt minimum estimating noise criterion to calculate equalizing coefficient, and carry out equilibrium, specifically comprise: the equalizing coefficient W that obtains each reception antenna correspondence by following formula _i:

$W_i=[W_i\left(1\right),W_i\left(2\right),...,W_i\left(M\right)]=\frac{H_i^{*}}{{\left|H_i\right|}^2+{{\mathrm{\σ}}_i}^2};$

Judge noise estimation values sigma ₁ ²Whether less than σ ₂ ², if then select W ₁As equalizing coefficient, with Z (k)=W ₁(k) R ₁(k) carry out equilibrium treatment for the equalization algorithm formula; If not, then select W ₂As equalizing coefficient, with Z (k)=W ₂(k) R ₂(k) carry out equilibrium treatment for the equalization algorithm formula;

Wherein, H _i ^*Be vectorial H _iConjugation; | H _i| be vectorial H _iMould; I is the numbering of antenna, (i=1,2); K=1 ..., M; R ₁(k), R ₂(k) be vector respectively

In value; W ₁(k), W ₂(k) be vectorial W respectively ₁, W ₂In value.

On the other hand, the present invention also provides double-antenna receiving diversity system in a kind of single-carrier frequency domain equalization system, and described system comprises:

Synchronous processing unit is used for the received signal of two reception antennas is carried out Synchronous Processing;

Channel estimating unit is used for the received signal after synchronous is carried out channel estimating, obtains frequency domain response H ₁, H ₂, and obtain the noise estimation values sigma of described received signal simultaneously ₁ ², σ ₂ ²

The equilibrium treatment unit is used for when described noise estimation values sigma ₁ ²Or σ ₂ ²During greater than preset threshold value K, adopt minimum estimating noise criterion to calculate equalizing coefficient, and carry out equilibrium; When described noise estimation values sigma ₁ ²And σ ₂ ²When all being not more than described threshold k, adopting maximum merging criterion to calculate equalizing coefficient, and carry out equilibrium.

Beneficial effect of the present invention is as follows:

The present invention passes through at different situations, adopt different criterions to calculate equalizing coefficient, carry out equilibrium treatment, avoided under the deep fade situation, the defective of the mis-behave that may cause based on maximum merging criterion diversity technique, under a reception antenna can't the situation of normal synchronized, also can obtain best diversity gain even guarantee.

Description of drawings

Fig. 1 is the structural representation of Frame in the SC-FDE system in the prior art;

Fig. 2 is the flow chart that carries out double-antenna receiving diversity method in the single-carrier frequency domain equalization system in the prior art;

1 one kinds of flow charts that carry out double-antenna receiving diversity method in the single-carrier frequency domain equalization system of Fig. 3 embodiment of the invention;

The structural representation of the pilot data that relates in Fig. 4 embodiment of the invention 1;

The structural representation of double-antenna receiving diversity system in 2 one kinds of single-carrier frequency domain equalization systems of Fig. 5 embodiment of the invention.

Embodiment

Below in conjunction with accompanying drawing and embodiment, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, does not limit the present invention.

As shown in Figure 3, the embodiment of the invention 1 relates to double-antenna receiving diversity method in a kind of single-carrier frequency domain equalization system, and this method may further comprise the steps:

Step S101 carries out Synchronous Processing to the received signal of two reception antennas.The method of carrying out Synchronous Processing can be existing any method, owing to there has been the method for handling with method in the prior art, therefore, this patent no longer describes description in detail.

Step S102 carries out channel estimating to the received signal synchronously, obtains frequency domain response H ₁, H ₂, and obtain the noise estimation values sigma of described received signal simultaneously ₁ ², σ ₂ ²

Current received signal frame to two reception antennas carries out the energy normalized processing respectively.Carry out energy normalized and handle, as long as get final product through existing digital AGC (AUTO GAIN CONTROL, automatic gain control) chip.

The leader block sequence that the transmitting terminal of sending signal for two described reception antennas is used for channel estimating is the UW sequence, u=[u (1) ..., u (M)], its Fourier changing value is U _Fft=[U (1) ... U (M)].The UW sequence, i.e. unique word (Unique Word) sequence is generally chu sequence, frank-zadaff sequence, the PN sequence of IEEE802.16a standard code.

From described received signal, extract the pilot data that is used for channel estimating

(i=1,2); Wherein, the pilot data length overall is 2M, forms (structure as shown in Figure 4) by the UW data of two M length.I represents the numbering of antenna.

To pilot data

Carry out fast Fourier transform, obtain

Obtain pilot data

Frequency domain information;

Obtain the noise estimation value of each reception antenna received signal by following formula:

${{\mathrm{\σ}}_1}^2=\frac{{\left|R_1\left(2\right)\right|}^2+{\left|R_1\left(4\right)\right|}^2+\·\·\·+{\left|R_1\left(M\right)\right|}^2}{2M};$

${{\mathrm{\σ}}_2}^2=\frac{{\left|R_2\left(2\right)\right|}^2+{\left|R_2\left(4\right)\right|}^2+\·\·\·+{\left|R_2\left(M\right)\right|}^2}{2M};$

Obtain frequency domain response H by following formula ₁, H ₂:

$H_1=[h_1\left(1\right),...,h_1\left(M\right)]=\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{R}_1(2n-1)/U\left(n\right);$

$H_2=[h_2\left(1\right),...,h_2\left(M\right)]=\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{R}_2(2n-1)/U\left(n\right);$

Wherein, R ₁(2), R ₁(4) ..., R ₁(M) be vector

In value; R ₂(2), R ₂(4) ..., R ₂(M) be vector

In value; U (n) is vectorial U _FftIn value.

Step S103 judges whether σ ₁ ²And σ ₂ ²All be not more than preset threshold value K, if then change step S104; Otherwise, then change step S105.The setting of threshold k can be rule of thumb, and the signal transmission environment that the result is concrete is provided with.Also can carry out experimental setting earlier, then,, adjust, finally obtain appropriate threshold according to the quality of signal transmission quality.

Step S104 is when described noise estimation values sigma ₁ ²And σ ₂ ²When all being not more than described threshold k, adopting maximum merging criterion to calculate equalizing coefficient, and carry out equilibrium.

At first, obtain the equalizing coefficient W of each reception antenna correspondence by following formula _i:

$W_i=[W_i\left(1\right),W_i\left(2\right),...,W_i\left(M\right)]=\frac{H_i^{*}}{{\left|H_1\right|}^2+{\left|H_2\right|}^2+{{\mathrm{\σ}}_1}^2};$

Then, according to obtaining equalizing coefficient W _i, carry out equilibrium treatment by following equalization algorithm formula:

Z(k)＝W ₁(k)·R ₁(k)+W ₂(k)·R ₂(k)；

Wherein, H _i ^*Be vectorial H _iConjugation; | H _i| be vectorial H _iMould; I is the numbering of antenna, (i=1,2); K=1 ..., M; R ₁(k), R ₂(k) be vector respectively

In value; W ₁(k), W ₂(k) be vectorial W respectively ₁, W ₂In value.

Step S105 is when described noise estimation values sigma ₁ ²Or σ ₂ ²During greater than threshold k, adopt minimum estimating noise criterion to calculate equalizing coefficient, and carry out equilibrium.

At first, obtain the equalizing coefficient W of each reception antenna correspondence by following formula _i:

$W_i=[W_i\left(1\right),W_i\left(2\right),...,W_i\left(M\right)]=\frac{H_i^{*}}{{\left|H_i\right|}^2+{{\mathrm{\σ}}_i}^2};$

Then, judge noise estimation values sigma ₁ ²Whether less than σ ₂ ², if then select W ₁As equalizing coefficient, with Z (k)=W ₁(k) R ₁(k) carry out equilibrium treatment for the equalization algorithm formula; If not, then select W ₂As equalizing coefficient, with Z (k)=W ₂(k) R ₂(k) carry out equilibrium treatment for the equalization algorithm formula.By above-mentioned selection, can select the antenna reception data of minimal noise correspondence to carry out equilibrium, and then obtain best diversity gain.

Wherein, H _i ^*Be vectorial H _iConjugation; | H _i| be vectorial H _iMould; I is the numbering of antenna, (i=1,2); K=1 ..., M; R ₁(k), R ₂(k) be vector respectively

In value; W ₁(k), W ₂(k) be vectorial W respectively ₁, W ₂In value.

On the other hand, the embodiment of the invention 2 relates to double-antenna receiving diversity system in a kind of single-carrier frequency domain equalization system, and described system comprises:

Synchronous processing unit 201 is used for the received signal of two reception antennas is carried out Synchronous Processing;

Channel estimating unit 202 is connected with synchronous processing unit 201, is used for the received signal after synchronous is carried out channel estimating, obtains frequency domain response H ₁, H ₂, and obtain the noise estimation values sigma of described received signal simultaneously ₁ ², σ ₂ ²

Equilibrium treatment unit 203 is connected with channel estimating unit 202, is used for when described noise estimation values sigma ₁ ²Or σ ₂ ²During greater than preset threshold value K, adopt minimum estimating noise criterion to calculate equalizing coefficient, and carry out equilibrium; When described noise estimation values sigma ₁ ²And σ ₂ ²When all being not more than described threshold k, adopting maximum merging criterion to calculate equalizing coefficient, and carry out equilibrium.

The method that the double-antenna receiving diversity system of present embodiment carries out equilibrium treatment is identical with the method that embodiment 1 relates to, and therefore, is not described in detail in the present embodiment.

Because the signal to noise ratio of received signal has determined the precision of synchronization module.Under the wireless mobile communications channel, certainly exist deep fade constantly, this moment, the signal to noise ratio of received signal was very low, will inevitably cause inaccurately synchronously, and this can have a strong impact on the accuracy of channel estimating, and adopt the diversity technique of maximum merging criterion this moment is infeasible.Because calculating noise estimated value of the present invention utilizes synchronizing information to obtain, therefore do not obtain synchronous the time when front end data, resulting noise estimation value will depart from normal value fully.It is synchronous preferably just to judge roughly according to this point whether receiving terminal obtains.After judging that certain receiving terminal does not obtain accurately synchronously, adopt minimum estimating noise criterion to calculate equalizing coefficient and carry out equilibrium, just can get rid of the reception antenna participation diversity of timing error.So just avoided the defective of the mis-behave that may cause based on maximum merging criterion diversity technique under the deep fade situation, can't also can obtain best diversity gain under the situation of normal synchronized at a reception antenna even guarantee.

Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.

Claims (7)

1. double-antenna receiving diversity method in the single-carrier frequency domain equalization system is characterized in that, said method comprising the steps of:

Received signal to two reception antennas is carried out Synchronous Processing;

Received signal is synchronously carried out channel estimating, obtain frequency domain response H ₁, H ₂, and obtain the noise estimation values sigma of described received signal simultaneously ₁ ², σ ₂ ²

When described noise estimation values sigma ₁ ²Or σ ₂ ²During greater than preset threshold value K, adopt minimum estimating noise criterion to calculate equalizing coefficient, and carry out equilibrium; When described noise estimation values sigma ₁ ²And σ ₂ ²When all being not more than described threshold k, adopting maximum merging criterion to calculate equalizing coefficient, and carry out equilibrium.

2. double-antenna receiving diversity method in the single-carrier frequency domain equalization system as claimed in claim 1 is characterized in that, the leader block sequence that the transmitting terminal of sending signal for two described reception antennas is used for channel estimating is the UW sequence, u=[u (1), ..., u (M)], its Fourier changing value is U _Fft=[U (1) ... U (M].

3. double-antenna receiving diversity method in the single-carrier frequency domain equalization system as claimed in claim 2 is characterized in that, to before the received signal after is synchronously carried out channel estimating, also comprises:

From described received signal, extract the pilot data that is used for channel estimating ${\stackrel{\→}{r}}_i=[r_i\left(1\right),...,r_i\left(2M\right)],$ (i=1,2); Wherein, the pilot data length overall is 2M, is made up of the UW data of two M length, and i represents the numbering of antenna.

4. double-antenna receiving diversity method in the single-carrier frequency domain equalization system as claimed in claim 3 is characterized in that, obtains frequency domain response H ₁, H ₂And noise estimation values sigma ₁ ², σ ₂ ², the tool bag is drawn together following steps:

To pilot data

Carry out fast Fourier transform, obtain ${\stackrel{\→}{R}}_1=[R_1\left(1\right),...,R_1\left(2M\right)]=\mathrm{FFT}\left({\stackrel{\→}{r}}_1\right),$ ${\stackrel{\→}{R}}_2=[R_2\left(1\right),...,R_2\left(2M\right)]=\mathrm{FFT}\left({\stackrel{\→}{r}}_2\right),$ Obtain pilot data Frequency domain information;

Obtain the noise estimation value of each reception antenna received signal by following formula:

${\mathrm{\σ}}_1^2=\frac{{\left|R_1\left(2\right)\right|}^2+{\left|R_1\left(4\right)\right|}^2+...+{\left|R_1\left(M\right)\right|}^2}{2M};$

${\mathrm{\σ}}_2^2=\frac{{\left|R_2\left(2\right)\right|}^2+{\left|R_2\left(4\right)\right|}^2+...+{\left|R_2\left(M\right)\right|}^2}{2M};$

Obtain frequency domain response H by following formula ₁, H ₂:

$H_1=[h_1\left(1\right),...,h_1\left(M\right)]=\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{R}_1(2n-1)/U\left(n\right);$

$H_2=[h_2\left(1\right),...,h_2\left(M\right)]=\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{R}_2(2n-1)/U\left(n\right);$

Wherein, R ₁(2), R ₁(4) ..., R ₁(M) be vector

In value; R ₂(2), R ₂(4) ..., R ₂(M) be vector

In value; U (n) is vectorial U _FftIn value.

5. double-antenna receiving diversity method in the single-carrier frequency domain equalization system as claimed in claim 4 is characterized in that, adopts maximum merging criterion to calculate equalizing coefficient, and carries out equilibrium, specifically comprises:

Obtain the equalizing coefficient W of each reception antenna correspondence by following formula _i:

$W_i=[W_i\left(1\right),W_i\left(2\right),...,W_i\left(M\right)]=\frac{H_i^{*}}{{\left|H_1\right|}^2+{\left|H_2\right|}^2+{\mathrm{\σ}}_1^2};$

Obtain equalizing coefficient W _iAfter, carry out equilibrium treatment by following equalization algorithm formula:

Z(k)＝W ₁(k)·R ₁(k)+W ₂(k)·R ₂(k)；

Wherein, H _i ^*Conjugation for vectorial Hi; | H _i| be vectorial H _iMould; I is the numbering of antenna, (i=1,2); K=1 ..., M; R ₁(k), R ₂(k) be vector respectively In value; W ₁(k), W ₂(k) be vectorial W respectively ₁, W ₂In value.

6. double-antenna receiving diversity method in the single-carrier frequency domain equalization system as claimed in claim 4 is characterized in that, adopts minimum estimating noise criterion to calculate equalizing coefficient, and carries out equilibrium, specifically comprises:

Obtain the equalizing coefficient W of each reception antenna correspondence by following formula _i:

$W_i=[W_i\left(1\right),W_i\left(2\right),...,W_i\left(M\right)]=\frac{H_i^{*}}{{\left|H_i\right|}^2+{\mathrm{\σ}}_i^2};$

Judge noise estimation values sigma ₁ ²Whether less than σ ₂ ², if then select W ₁As equalizing coefficient, with Z (k)=W ₁(k) R ₁(k) carry out equilibrium treatment for the equalization algorithm formula; If not, then select W ₂As equalizing coefficient, with Z (k)=W ₂(k) R ₂(k) carry out equilibrium treatment for the equalization algorithm formula;

Wherein, H _i ^*Conjugation for vectorial Hi; | H _i| be vectorial H _iMould; I is the numbering of antenna, (i=1,2); K=1 ..., M; R ₁(k), R ₂(k) be vector respectively

In value; W ₁(k), W ₂(k) be vectorial W respectively ₁, W ₂In value.

7. double-antenna receiving diversity system in the single-carrier frequency domain equalization system is characterized in that described system comprises:

Synchronous processing unit is used for the received signal of two reception antennas is carried out Synchronous Processing;

Channel estimating unit is used for the received signal after synchronous is carried out channel estimating, obtains frequency domain response H ₁, H ₂, and obtain the noise estimation values sigma of described received signal simultaneously ₁ ², σ ₂ ²

The equilibrium treatment unit is used for when described noise estimation values sigma ₁ ²Or σ ₂ ²During greater than preset threshold value K, adopt minimum estimating noise criterion to calculate equalizing coefficient, and carry out equilibrium; When described noise estimation values sigma ₁ ²And σ ₂ ²When all being not more than described threshold k, adopting maximum merging criterion to calculate equalizing coefficient, and carry out equilibrium.

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