CN100382633C - Intelligent antenna realizing method based on software radio - Google Patents

Abstract

The present invention discloses a smart antenna realization method based on software radio, which is applied to a communication system with smart antennas. The present invention is characterized in that the present invention comprises: according to the eigen values of the correlation matrix of array received signals and the deflection of inband power spectra, the communication environment is divided into channels of different types, and for different types of channels, different beam forming methods are adopted. The method of the present invention can obtain good communication quality in various complicated communication environments.

Description

A kind of smart antenna implementation method based on software radio

Technical field

The present invention relates to the reception/lift-off technology of smart antenna in the digital radio communication, particularly a kind of adaptive beam formation method of intelligent antenna base station of TDMA mode.

Background technology

In recent years at moving communicating field, receive increasing concern with the application of the intelligent antenna technology that rises to purpose of effective utilization of frequency, communication quality.So-called intelligent antenna technology promptly adopts plural single antenna array element to form antenna array, the signal that each array element receives is weighted summation through after the radio frequency processing with proper weight, can reach the effect of directional reception, a weight vector correspondence certain beam pattern.The essence of weighting is a kind of space filtering, smart antenna is by the aerial array received signal, and carry out digital beam forming by Digital Signal Processing, just desired signal is strengthened by phase place and the amplitude of adjusting the aerial array received signal, and other interference signal is weakened, and finally makes the signal to noise ratio maximum of desired signal.

The intelligent base station of TDMA (Time Division Multiple Access, time division multiple access) mode be early with one of business-like communication system of smart antenna.Intelligent base station when receiving, according to information by preset signal content known portions such as signal preamble that a plurality of bay received or unique words, Yi Bian adjust weight vectors, Yi Bian separate signal from specific travelling carriage; When sending, utilize to change weight vectors, make directionality towards specific travelling carriage, keep communication quality thereby prevent to a certain extent to disturb, under spatial multiplexing mode, carry out the communication of a plurality of travelling carriages.

So far, people have proposed many patents relevant with intelligent antenna technology, as Chinese patent 99815952 (signal processing method of computing optimal weight vector of adaptive antenna array system and equipment, publication number: CN1334978), the self-adapting program of computing array antenna system optimal weight vector is proposed, this array antenna system is provided under the Blind Source environment in the beam modes that upwards has its maximum gain along the moving target signal source side, improves the quality of communication and the capacity of communicating by letter by the optimal weight vector that makes the maximum array system of SINR (signal is to the ratio of interference+noise).Chinese patent 96194112 (base station equipments, and a kind of method of control antenna beam direction, publication number: CN1185250), the wireless base station is calculating first weighing vector corresponding to each of a plurality of travelling carriages, the cycle of the signal that sends from each extraction of described a plurality of travelling carriages by the signal that received by a plurality of antennas with the described first weighing vector weighting; And to the transmission periodic groups of each signal that obtains with the described first weighing vector weighting by described a plurality of antenna transmission of described a plurality of travelling carriages altogether with as a cycle period, communicate in a plurality of travelling carriages repeatedly with time division multiplexing.

Most crucial technology is an adaptive beam formation technology in the antenna system, and antenna system depends primarily on the performance of adaptive beam formation method to the improvement degree of communication system.Wherein the computation complexity of adaptive beam formation method and convergence rate are one of difficult problems of restriction adaptive antenna development.In the above-mentioned patent that relates to adaptive smart antenna, perhaps just propose the framework that system realizes, do not had concrete implementation method; Perhaps the used adaptive beam formation method of Ti Chuing only adopts single wave beam computational methods, and being difficult to so all has the excellent communications quality in the communication environment of multiple complexity.

Summary of the invention

Technical problem to be solved by this invention provide a kind of more specifically, based on the smart antenna implementation method of software radio, be difficult to tackle the technical problem that communication quality is provided to solve the existing smart antenna of single adaptive beam formation method that adopts in the communication environment of multiple complexity.

For achieving the above object, the invention provides a kind of smart antenna implementation method based on software radio, be applied to have the communication system of smart antenna, its characteristics are, comprise: according to the characteristic value and the band internal power deviation of the correlation matrix of array received signal, communication environment is divided into dissimilar channels, and adopts different wave beam formation methods at dissimilar channels.

Above-mentioned method, its characteristics are that described dissimilar channel comprises: additive white Gaussian noise interference channel, co-channel interference channel and intersymbol interference channel; Described wave beam formation method comprises: wave beam formation method, improved weighing apparatus mould wave beam formation method and improved Wei Na that high specific merges separate wave beam formation method.

Above-mentioned method, its characteristics are that described method further comprises the steps: step 1, and array received signal data are carried out preliminary treatment; Step 2 is carried out the synchronous of signal data; Step 3 is carried out the estimation and the compensation of carrier wave frequency deviation and phase deviation to signal data; Step 4 is carried out the identification of channel type according to signal data; Step 5 is selected wave beam formation method and is carried out up weights calculating according to channel type; Step 6, wave beam forms; Step 7 adopts

Demodulation method carries out demodulation; Step 8 is carried out CRC check; Step 9 is carried out the calculating of descending weights.

Above-mentioned method, its characteristics are that described step 4 further comprises: step a, the autocorrelation matrix R=XX of computing array received signal ^HStep b, try to achieve characteristic root λ corresponding to characteristic vector V according to following formula: RV=λ V, ${\mathrm{\λ}}_1\≥{\mathrm{\λ}}_2\≥,...={\mathrm{\λ}}_M={\mathrm{\σ}}_N^2,$ σ wherein _N ²It is noise power; Step c estimates that the power of each passage of array received signal is respectively P ₁, P ₂..., P _MSteps d is carried out the differentiation of validity feature root: σ _N ²Be noise power, if $\mathrm{\λ}\≥{\mathrm{\σ}}_N^2+{\mathrm{\δ}}_{\mathrm{\λ}},$ Then looking this λ is validity feature root, wherein δ _λBe the concrete parameter of determining according to real system; Step e, be with the internal power deviation ratio | P _i-P _j|＜δ _p, i wherein, j=1,2 ... M, and i ≠ j, δ _pBe the concrete parameter of determining according to real system; Step f, judge as follows to channel classification according to parameter: channel type one: the validity feature radical is 1, and power deviation is less, and have only desired signal and additive white Gaussian noise in the channel this moment, and the time delay expansion is less; Channel type two: the validity feature radical is 1, and power deviation is bigger, and existing desired signal also has interference signal in the channel at this moment, but the time delay expansion is little, and certain angle spread is arranged, and mainly shows as cochannel and disturbs; Channel type three: the validity feature radical is greater than 1, and power deviation is less, and this moment, the time delay expansion of desired signal was bigger, and angle spread is less, mainly shows as intersymbol interference; Channel type four: the validity feature radical is greater than 1, and power deviation is bigger, and this moment, desired signal and interference signal all existed certain time delay expansion and angle spread.

Above-mentioned method, its characteristics are, described step 5 comprises: the wave beam formation method at described channel type one adopts high specific to merge, adopt improved weighing apparatus mould wave beam formation method at channel type two, and adopt improved Wei Na to separate wave beam formation method at described channel type three.

Above-mentioned method, its characteristics are that described step 1 further comprises: data are carried out normalization, reduce the amplitude of data, so that choosing of step-length restrains adaptive algorithm as early as possible; Reference signal is carried out A/D quantize, enlarge amplitude, make the amplitude of reference signal consistent as far as possible with the amplitude size of actual signal.

Above-mentioned method, its characteristics are that described step 2 also comprises: after bit synchronization is finished, get the part code element and do every the position related operation and carry out symbol synchronization.

The method of the above, its characteristics are, adopt 16 CRC of ITU-T in the described step 8, if the CRC check result is correct, then carry out next step; Otherwise, give up this data.

Above-mentioned method, its characteristics are that described communication system is the personal handyphone system of time division multiple access way.

Above-mentioned method, its characteristics are that described step 9 further comprises: up weights are got conjugation and be multiplied by the correction weights, thereby up weights are directly used in descending weights.

Technique effect of the present invention is:

The present invention has been owing to adopted adaptive beam formation method based on software radio, compares with existing adaptive beam formation method to have lot of advantages.The present invention utilizes the receiving array data communication channel is estimated and to be discerned, channel is divided into additive white Gaussian noise channel, co-channel interference channel and intersymbol interference channel, again according to different channel type select suitable (as high specific merge, improved weighing apparatus mould and improved Wei Na separate etc.) beamforming algorithm.The invention solves the limitation that adopts single adaptive beam-forming algorithm, improved the scope of application of antenna system.In addition, method of the present invention can be followed the tracks of user's direction of arrival, adaptive adjusting weight vector; Can form the maximum sensing of wave beam at the direction of arrival of desired user, form zero in the interference user direction and fall into, effectively suppress the influence of interference.

Description of drawings

Fig. 1 method flow diagram of the present invention;

Fig. 2 wireless communications environment of the present invention detects and the channel identification flow chart;

Fig. 3 practical communication example environments figure.

Embodiment

Be described in further detail below in conjunction with the enforcement of accompanying drawing technical scheme.

Fig. 1 is a method flow diagram of the present invention.In the adaptive mode smart antenna, the weights that corresponding spatial domain or sky, time domain are handled can be adjusted arbitrarily according to certain adaptive algorithm, current transmission environment is carried out the maximum possible coupling, corresponding smart antenna reception/launching beam can be to point to arbitrarily.In practical communication, channel situation is very complicated, and is present, adopts single a certain adaptive beam formation method to make it that good performance that gets all be arranged in various environment, implements comparatively difficulty.Therefore, by the characteristic of analyzing communication channel, selecting the corresponding beamforming algorithm that comparatively is fit to, thereby make intelligent antenna base station have adaptability widely, is starting point of the present invention.

To the effect that of the present invention, characteristic value and band internal power deviation according to the correlation matrix of array received signal, the channel that communication environment is divided into types such as additive white Gaussian noise interference, co-channel interference and intersymbol interference, adopt corresponding high specific to merge (MRC at dissimilar channels, Maximal RatioCombining), improved weighing apparatus mould (Advanced CAM, Advanced Constant ModulusAlgorithm) and Wei Na separate wave beam formation methods such as (Wiener).The present invention has improved the limitation of single adaptive beam-forming algorithm applied environment, has enlarged the scope of application of smart antenna to communication environment, fast moving that can the real-time tracking user and can resist multiple interference environment; Simultaneously based on the system configuration of software radio, comparing with the normal procedure intelligent antenna does not need big hardware cost, has improved the ratio of performance to price of antenna system greatly.

Below will describing with PHS (Personal Handy-phone System, personal handyphone system claims Personal Handyphone System again) the system self-adaption wave beam formation method of TDMA mode, is example with the CCH time slot here, similar with it as for the TCH time slot, no longer describes in detail.

Method set forth in the present invention can realize by following several steps:

Step 101, beginning;

Step 102, the data preliminary treatment:

Channel fading is bigger in practical communication, needs higher quantization digit to satisfy enough dynamic ranges.But this can cause the increase of subsequent calculations amount, and is bigger to the pressure of DSP operand.Simultaneously, in adaptive algorithm, input signal amplitude is bigger to intelligent influential effect, need limit signal amplitude.In order to solve above-mentioned two problems, need carry out preliminary treatment to input signal, concrete grammar is:

At first, used data are carried out normalization, reduce the amplitude of data, be convenient to choosing of step-length, adaptive algorithm is restrained as early as possible;

Secondly, reference signal is carried out A/D quantize, enlarge amplitude, make the amplitude of reference signal consistent as far as possible with the amplitude size of actual signal.

Step 103, bit synchronization and UW word coupling:

At first, utilize the PR in the frame structure to carry out bit synchronous method.Because PR is designed to 1001 code streams that repeat, the phase difference of the IQ signal of process π/4DQPSK modulated I Q signal and front two is a pi/2.The code stream of supposing modulation back PR is: d ₁, d ₂... d _N, then have

$d_n/d_{n-2}=e^{j\frac{\mathrm{\π}}{2}}$

Because the sample rate that system adopts is 5 times of chip rates, so the 10th sampled point of arbitrary sampled point and its front all differs pi/2.Suppose that sampled point is followed successively by s ₁, s ₂S _L, then have

$s_n/s_{n-10}=e^{j\frac{\mathrm{\π}}{2}}$

For reducing The noise, the data of 10 sampled points of being separated by are done coherent superposition:

$x_k=\underset{l=0}{\overset{L/10-1}{\mathrm{\Σ}}}{s}_{k+l*10{(-j)}^l}$ k＝1，2，…10

Wherein-phase place of j is-pi/2 that above-mentioned coherent superposition computing can only can be finished through plus and minus calculation without multiplying.

We have obtained 10 values to handle the back like this, with the first five x _kWith back five x _kThe addition of mould value, ask that the maximum place is the bit synchronization point in these 5 values.

Secondly, carry out UW word coupling.In fact, through above-mentioned bit synchronous operation, finished the symbol synchronization of error in two symbol ranges.When time delay error in the real system during duration, uses above-mentioned bit synchronous operation just enough less than two code elements.But, because the PR sequence is the periodic sequence that is the cycle with 2 code element durations, so use PR can bring the phase ambiguity of 2 code element durations synchronously.In order to address this problem, can consider to use the UW word to carry out symbol synchronization.Because this moment, bit synchronization was finished, so realize that symbol synchronization is more or less freely this moment, did every the position related operation as long as get the part code element of UW.

Step 104, the estimation of carrier wave frequency deviation and phase deviation and compensation.In the tentation data stream one section known array (SS+PR+UW) is arranged, be made as s ₁, s ₂S _N, the Nonlinear Transformation in Frequency Offset Estimation value is provided by following formula:

$e^{j\widehat{\mathrm{\ω}}}=\frac{\underset{n=2}{\overset{N}{\mathrm{\Σ}}}{x}_n{s}_n^{*}{\left(x_{n-1}{s}_{n-1}^{*}\right)}^{*}}{\left|\underset{n=2}{\overset{N}{\mathrm{\Σ}}}{x}_n{s}_n^{*}{\left(x_{n-1}{s}_{n-1}^{*}\right)}^{*}\right|}$

The estimated value of phase deviation is provided by following formula:

$e^{j\widehat{\mathrm{\θ}}}=\frac{\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{x}_n{e}^{-j\widehat{\mathrm{\ω}}n}{s}_n^{*}}{\left|\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{x}_n{e}^{-j\widehat{\mathrm{\ω}}n}{s}_n^{*}\right|}$

After estimating carrier wave frequency deviation and phase deviation, use following formula to compensate:

$y_n=x_n{e}^{-j\widehat{\mathrm{\ω}}n-j\widehat{\mathrm{\θ}}}$

Generally, the length that reference sequences is chosen is long more, and the result of carrier wave frequency deviation and phase estimation is just good more, so choose all known arrays as the reference sequence as far as possible.Carrying out simulation result by the actual data that obtain and show, is not each group data frequency deviation and phase compensation fully, and some data can be come in full remuneration, and some data can most of compensate.In a word, after top method processing, can improve the influence of carrier wave frequency deviation and phase deviation greatly.

Step 105, the identification of channel type.Specific implementation method is hereinafter in conjunction with Fig. 2 explanation.

Step 106, the selection of adaptive algorithm and the calculating of up weights.According to the channel circumstance feature of types such as additive white Gaussian noise interference, co-channel interference and intersymbol interference to channel classification, for channel type 1, channel type 2, channel type 3 and channel type 4 select respectively that high specific merges, wave beam formation method such as improved weighing apparatus mould and sampling matrix are inverted.

High specific merging method and the sampling matrix method of inverting all has application to a certain degree, no longer describes in detail here.

The main process of improved constant modulus algorithm is as follows:

Separate the initial weight W that obtains constant modulus algorithm according to Wei Na ₀=(XX ^H) ^-1Xd ^H, wherein d is a reference signal, XX ^H=R is the autocorrelation matrix of array received signal, and the R value is obtained when channel identification, can directly quote here.

In the constant modulus algorithm of this patent, the cost function of the implementation method of permanent mould steepest descent is:

J＝E{||w ^H(n)x(n)|-|α|| ²}

Wherein $\mathrm{\α}=W_0^H\·X\left(0\right),$ Upgrade direction and choose iterative formula:

w(n+1)＝w(n)-μx(n)e ^*(n)

In the formula $e\left(n\right)=2[y\left(n\right)-\frac{y\left(n\right)}{\left|y\left(n\right)\right|}],$ μ is a step-length.

Step 107, wave beam forms.Several single channel signals are merged formation wave beam Y=W ^HX.

Step 108,

Demodulation.Adopt Demodulation method is as follows:

The code element of strange sequence number and even sequence number is separated, adjudicate respectively, concrete operations are:

$z_{2n-1}=\mathrm{sign}\left(y_{2n-1}{e}^{-\mathrm{j\π}/4}\right)e^{\mathrm{j\π}/4}/\sqrt{2}$

$z_{2n}=\mathrm{sign}\left(y_{2n}\right)/\sqrt{2}$

Wherein sign (y) expression is got symbol to real part and the imaginary part of y respectively.

Step 109, CRC check.Adopt 16 CRC of ITU-T, promptly increase by 16 bit redundant digits on every frame, its generator polynomial is 1+x ⁵+ x ¹²+ x ¹⁶If the CRC check result is correct, then carry out next step; Otherwise, give up this data.

Step 110, the calculating of descending weights.Because the PHS system adopts the working method of TDD, upward signal and downstream signal are operated in same frequency, through same channel, and the transmitting-receiving time interval only be 2.5ms, can think that the up-downgoing characteristic of channel remains unchanged.So up weights can be directly used in descending weights, only need be got conjugation with up weights and be multiplied by the correction weights and get final product.

Step 111 finishes.

Fig. 2 is that wireless communications environment detects and the channel identification flow chart, as shown in the figure, comprising:

Step 201, the autocorrelation matrix R=XX of computing array received signal ^H

Step 202, try to achieve characteristic root λ according to following formula corresponding to characteristic vector V:

R·V＝λ·V

Note ${\mathrm{\λ}}_1\≥{\mathrm{\λ}}_2\≥,...={\mathrm{\λ}}_M={\mathrm{\σ}}_N^2,$ σ wherein _N ²It is noise power.

Step 203 estimates that the power of each passage of array received signal is respectively P ₁, P ₂..., P _M

Step 204, σ is supposed in the differentiation of validity feature root _N ²Be noise power, if $\mathrm{\λ}\≥{\mathrm{\σ}}_N^2+{\mathrm{\δ}}_{\mathrm{\λ}},$ Then looking this λ is validity feature root, wherein δ _λBe the concrete parameter of determining according to real system.

Step 205, be with the internal power deviation ratio | P _i-P _j|＜δ _p, i wherein, j=1,2 ... M, and i ≠ j, δ _pBe the concrete parameter of determining according to real system.

Step 206 is judged channel classification according to parameter.Channel type 1 (206.1): validity feature radical=1, and power deviation is less; Have only desired signal and additive white Gaussian noise in the channel this moment, and the time delay expansion is less.Channel type 2 (206.2): validity feature radical=1, and power deviation is bigger; Existing desired signal also has interference signal in the channel at this moment, but the time delay expansion is little, and certain angle spread is arranged, and mainly shows as cochannel and disturbs.Channel type 3 (206.3): validity feature radical＞1, and power deviation is less; This moment, the time delay expansion of desired signal was bigger, and angle spread is less; Mainly show as intersymbol interference.Channel type 4 (206.4): validity feature radical＞1, and power deviation is bigger; This moment, desired signal and interference signal all existed certain time delay expansion and angle spread.

Fig. 3 is the schematic diagram of a certain regional wireless communications environment.Channel type 1 place is away from base station 300, signal power a little less than, noise is stronger; Channel type 1 place adopts the multi-beam maximum ratio to merge.2 of channel types are subjected to disturb from the cochannel of other sub-district, influence systematic function; Channel type 2 places adopt improved constant modulus algorithm opposing cochannel to disturb.There is serious intersymbol interference in channel type 3 places because the delay inequality of each multipath component is bigger; Channel type 3 places adopt improved dimension to receive the optimal solution algorithm to carry out digital beam and form.

As from the foregoing, the invention discloses a kind of smart antenna implementation method based on software and radio technique, the inventive method is compared with traditional smart antenna method has following characteristics:

The first, by the characteristic of analyzing communication channel, select the corresponding beamforming algorithm that comparatively is fit to, thereby make intelligent antenna base station have adaptability widely, improved algorithm keeps track speed greatly, satisfied the requirement that communication system is handled in real time.

The second, adopt the adaptive algorithm system of selection of software and radio technique, avoided the limitation of the single a certain adaptive beam method of formationing, that method is switched is succinct, it is quick to calculate, and has reduced hard-wired difficulty, is easy to Project Realization.

The 3rd, adopt beamforming algorithm based on software and radio technique, be easy to the upgrading and the maintenance of base station system.

The 4th, algorithm can be followed the tracks of user's direction of arrival, adaptive adjusting weight vector.Can form the maximum sensing of wave beam at the direction of arrival of desired user, fall into, effectively suppress the influence of interference and form zero in the interference user direction.

In a word, adopt method provided by the invention to realize that wave beam forms, under the less hardware cost condition of cost, improved the ratio of performance to price of intelligent antenna base station system greatly, Project Realization is convenient, and the performance that makes intelligent base station handle simultaneously improves greatly.

The above is preferred embodiment of the present invention only, is not to be used for limiting practical range of the present invention; Every according to equivalence variation and modification that the present invention did, all contained by claim of the present invention.

Claims (10)

1. smart antenna implementation method based on software radio, be applied to have the communication system of smart antenna, it is characterized in that, comprise: according to the characteristic value and the band internal power deviation of the correlation matrix of array received signal, communication environment is divided into dissimilar channels, and adopts different wave beam formation methods at dissimilar channels.

2. method according to claim 1 is characterized in that, described dissimilar channel comprises: additive white Gaussian noise interference channel, co-channel interference channel and intersymbol interference channel; Described wave beam formation method comprises: wave beam formation method, improved weighing apparatus mould wave beam formation method and improved Wei Na that high specific merges separate wave beam formation method.

3. method according to claim 2 is characterized in that described method further comprises the steps:

Step 1 is carried out preliminary treatment to array received signal data;

Step 2 is carried out the synchronous of signal data;

Step 3 is carried out the estimation and the compensation of carrier wave frequency deviation and phase deviation to signal data;

Step 4 is carried out the identification of channel type according to signal data;

Step 5 is selected wave beam formation method and is carried out up weights calculating according to channel type;

Step 6, wave beam forms;

Step 7 adopts

Demodulation method carries out demodulation;

Step 8 is carried out CRC check;

Step 9 is carried out the calculating of descending weights.

4. method according to claim 3 is characterized in that, described step 4 further comprises:

Step a, the autocorrelation matrix R=XX of computing array received signal ^H

Step b, try to achieve characteristic root λ corresponding to characteristic vector V according to following formula: RV=λ V, ${\mathrm{\λ}}_1\≥{\mathrm{\λ}}_2\≥,...={\mathrm{\λ}}_M={\mathrm{\σ}}_N^2,$ σ wherein _N ²It is noise power;

Step c estimates that the power of each passage of array received signal is respectively P ₁, P ₂..., P _M

Steps d is carried out the differentiation of validity feature root: σ _N ²Be noise power, if $\mathrm{\λ}\≥{\mathrm{\σ}}_N^2+{\mathrm{\δ}}_{\mathrm{\λ}},$ Then looking this λ is validity feature root, wherein δ _λBe the concrete parameter of determining according to real system;

Step e, be with the internal power deviation ratio | P _i-P _j|＜δ _p, i wherein, j=1,2 ... M, and i ≠ j, δ _pBe the concrete parameter of determining according to real system;

Step f, judge as follows to channel classification according to parameter: channel type one: the validity feature radical is 1, and power deviation is less, and have only desired signal and additive white Gaussian noise in the channel this moment, and the time delay expansion is less; Channel type two: the validity feature radical is 1, and power deviation is bigger, and existing desired signal also has interference signal in the channel at this moment, but the time delay expansion is little, and certain angle spread is arranged, and mainly shows as cochannel and disturbs; Channel type three: the validity feature radical is greater than 1, and power deviation is less, and this moment, the time delay expansion of desired signal was bigger, and angle spread is less, mainly shows as intersymbol interference; Channel type four: the validity feature radical is greater than 1, and power deviation is bigger, and this moment, desired signal and interference signal all existed certain time delay expansion and angle spread.

5. method according to claim 4, it is characterized in that, described step 5 comprises: the wave beam formation method that adopts the high specific merging at described channel type one, adopt improved weighing apparatus mould wave beam formation method at channel type two, adopt improved Wei Na to separate wave beam formation method at described channel type three.

6. according to claim 3,4 or 5 described methods, it is characterized in that described step 1 further comprises: data are carried out normalization, reduce the amplitude of data, so that choosing of step-length restrains adaptive algorithm as early as possible; Reference signal is carried out A/D quantize, enlarge amplitude, make the amplitude of reference signal consistent as far as possible with the amplitude size of actual signal.

7. method according to claim 6 is characterized in that, described step 2 also comprises: after bit synchronization is finished, get the part code element and do every the position related operation and carry out symbol synchronization.

8. method according to claim 6 is characterized in that, adopts ITU-T16 position CRC in the described step 8, if the CRC check result is correct, then carries out next step; Otherwise, give up this data.

9. method according to claim 6 is characterized in that, described communication system is the personal handyphone system of time division multiple access way.

10. method according to claim 9 is characterized in that, described step 9 further comprises: up weights are got conjugation and be multiplied by the correction weights, thereby up weights are directly used in descending weights.

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