CN101902245A - Method and device for calculating parameters for automatic frequency control by adopting combined detection - Google Patents

Abstract

The invention relates to a method and a device for calculating parameters for automatic frequency control by adopting combined detection, belonging to the technical field of telecommunication. The device comprises a hardware module for calculating relevant results and carrying out self-adapting bit width adjustment and a software module for calculating phases, filtering and calculating the parameters for the automatic frequency control. The method comprises the following steps of: firstly inputting the reception result of the combined detection to the hardware module, selecting the result symbol of the combined detection by the hardware module to carry out symbol hard decision, calculating multiple correlation of the result of the hard decision and corresponding combined detection data, calculating the multiple correlation of the obtained result again, carrying out self-adapting bit width adjustment of the hardware module on the results of the two multiple correlations, outputting the processed results of the two multiple correlations to software, filtering by the software and calculating the parameters for the automatic frequency control. Through the result of the combined detection of the data part in the TD-SCDMA time slot structure, the frequency swing is estimated by adopting a decision feedback method. By the combined detection including the common-frequency adjacent cells, the accepting of data of the interference of the common-frequency cells and the interference of the users of the cell is eliminated, and the deviation estimation of the local frequency and the network frequency is more reasonable and correct.

Description

Adopt the method and the device of joint-detection calculating parameters for automatic frequency control

Technical field

The present invention relates to a kind of method and device of calculating parameters for automatic frequency control, relate in particular to a kind of method and device that in the TD-SCDMA system, adopts the joint-detection calculating parameters for automatic frequency control, belong to technical field of telecommunications.

Background technology

In cordless communication terminal system, automatic frequency control AFC is an important function very.By automatic control adjustment to local oscillator frequencies so that itself and network side corresponding frequencies are consistent, with satisfy synchronously, the requirement of demodulation etc., the performance that improves terminal system is had crucial effects.

In the TD-SCDMA terminal, it is relevant that the reception result that generally adopts intermediate code Midambl (MA) and descending synchronous code SYNC-DL and corresponding training sequence carry out, and estimates frequency deviation, and then obtain the AFC parameter.Yet when having inter-frequency interference cell, if only co-channel interference being used as common noise handles, owing to there is fixing interference on SYNC-DL or the MA training sequence, in the phase place rotation value that will cause estimating by existing method, have a stationary phase deviation fixing, that can not eliminate, this will cause also existing in the final frequency offset estimating value frequency departure to a certain degree.Even there is not co-channel interference, when the MA on adopting TS0 carries out frequency offset estimating as training sequence, because except first corresponding MA Shift of Primary Common Control Physical Channel (P-CCPCH), also may there be other MA Shift, because the autocorrelative imperfection of MA sign indicating number, these other MA Shift can cause interference to frequency offset estimating equally.

Summary of the invention

Purpose of the present invention is exactly in order to solve the above-mentioned problems in the prior art, and a kind of method and device that adopts the joint-detection calculating parameters for automatic frequency control is provided.

Purpose of the present invention is achieved through the following technical solutions:

Adopt the method for joint-detection calculating parameters for automatic frequency control, it may further comprise the steps: 1. step imports the reception result of joint-detection to hardware module;

The step 2. hardware module outcome symbol of choosing joint-detection is carried out the symbol hard decision;

Step is 3. to hard decision result and corresponding joint-detection data computation multiple correlation;

Step 4. to step 3. the gained result calculate multiple correlation once more;

Step 5. hardware module is carried out the adjustment of self adaptation bit wide to the result of secondary multiple correlation;

Step 6. software read step result is 5. carried out filtering, and controlled parameter converts.

The method of above-mentioned employing joint-detection calculating parameters for automatic frequency control, wherein: the reception result of described step in 1. is with the mode serial input of symbol data streams.

Further, the method for above-mentioned employing joint-detection calculating parameters for automatic frequency control, wherein: the described step 2. real part and the imaginary part of middle symbol hard decision output signal is the real part of input signal and the symbolic information of imaginary part.

Further, the method of above-mentioned employing joint-detection calculating parameters for automatic frequency control, wherein: it is to S symbol in the first half symbol data (DATA1) of certain code channel of a TD-SCDMA time slot that described step is calculated multiple correlation in 3., and declares the result accordingly firmly and carries out multiple correlation and obtain Corr1 as a result; To S symbol in the latter half symbol data (DATA2), and declare the result accordingly firmly and carry out multiple correlation and obtain Corr2 as a result.

Again further, the method for above-mentioned employing joint-detection calculating parameters for automatic frequency control, wherein: 4. described step is carried out multiple correlation to Corr1 and Corr2 and is obtained Corr3.

Again further, the method for above-mentioned employing joint-detection calculating parameters for automatic frequency control, wherein: 5. described step carries out the adjustment of self adaptation bit wide to the real part imaginary part of Corr3.

Again further, the method for above-mentioned employing joint-detection calculating parameters for automatic frequency control, wherein: 6. described step reads hardware module completing steps result 5. by software, carries out filtering and convert obtaining parameters for automatic frequency control.

Adopt the device of joint-detection calculating parameters for automatic frequency control, wherein: hardware module and software module, described hardware module comprises the hard decision device, the output of hard decision device is connected with the input of first complex correlator, the output of first complex correlator is connected with the input of second complex correlator, the output of second complex correlator connects the input of self adaptation bit wide adjuster, self adaptation bit wide regulator output is connected into software module, is connected with time schedule controller simultaneously on first complex correlator and second complex correlator.

The device of above-mentioned employing joint-detection calculating parameters for automatic frequency control, wherein: described first complex correlator and second complex correlator can be by multiplexing realizations of complex correlator on hardware module realizes.。

Further, the device of above-mentioned employing joint-detection calculating parameters for automatic frequency control, wherein: described software module comprises the phase calculation assembly, self adaptation bit wide regulator output is connected into the input of computation module, and the output of computation module connects the input of filtering and automatic frequency control assembly.

The outstanding substantive distinguishing features and the obvious improvement of technical solution of the present invention is mainly reflected in: by the joint detection results of data division in the TD-SCDMA structure of time slot, adopt the method for decision-feedback to estimate frequency deviation.By comprising the joint-detection of facing the sub-district, eliminated the reception data that co-frequency cell interference and other users of this sub-district disturb like this, the skew of local frequency and network has been estimated more rationally with accurate with frequency.This shows that expanded the space for the technological progress of this area, implementation result is good.

Description of drawings

Purpose of the present invention, advantage and characteristics will illustrate by the non-limitative illustration of following preferred embodiment and explain.These embodiment only are the prominent examples of using technical solution of the present invention, and all technical schemes of taking to be equal to replacement or equivalent transformation and forming all drop within the scope of protection of present invention.In the middle of these accompanying drawings,

Fig. 1 is the device construction schematic diagram that adopts the joint-detection calculating parameters for automatic frequency control;

What Fig. 2 was the method that adopts the joint-detection calculating parameters for automatic frequency control to DATA chooses the enforcement schematic diagram.

The implication of each Reference numeral is as follows among the figure:

1 hard decision device, 2 first complex correlator

3 second complex correlator, 4 time schedule controllers

5 self adaptation bit wide adjusters, 6 phase calculation assemblies

7 filtering and automatic frequency control

Assembly

Embodiment

The method of employing joint-detection calculating parameters for automatic frequency control as shown in Figure 1 and Figure 2, its special feature is to comprise following process: at first, by calculating correlated results and doing the hardware module that the self adaptation bit wide is adjusted, the reception result of input joint-detection, reception result is with the mode serial input of symbol data streams specifically.

Subsequently, the outcome symbol of selected part joint-detection carries out the symbol hard decision.Specifically, the real part of symbol hard decision output signal and imaginary part are the real part of input signal and the symbolic information of imaginary part.

Then, to hard decision result and corresponding joint-detection data computation multiple correlation, and the gained result calculated multiple correlation once more.In conjunction with actual, calculate multiple correlation and be S symbol in the first half symbol data (DATA1) of certain code channel of a TD-SCDMA time slot, and declare the result accordingly firmly and carry out multiple correlation and obtain Corr1 as a result; To S symbol in the latter half symbol data (DATA2), and declare the result accordingly firmly and carry out multiple correlation and obtain Corr2 as a result; Corr1 and Corr2 are carried out multiple correlation obtain Corr3.

Next, Corr3 is carried out the adjustment of self adaptation bit wide, under the situation of restriction bit wide, guarantee that phase information is constant, and provide maximum number of significant digit results, to guarantee precision.

Further, adopt the device of joint-detection calculating parameters for automatic frequency control, its special feature is: hardware module and software module.

In conjunction with Fig. 1 specifically, described hardware module comprises hard decision device 1, the output of hard decision device 1 is connected with the input of first complex correlator 2, the output of first complex correlator 2 is connected with the input of second complex correlator 3, the output of second complex correlator 3 connects the input of self adaptation bit wide adjuster 5, the output of self adaptation bit wide adjuster 5 is connected into software module, is connected with time schedule controller 4 simultaneously on first complex correlator 2 and second complex correlator 3.Software module comprises phase calculation assembly 6, and the output of self adaptation bit wide adjuster 5 is connected into the input of computation module, and the output of computation module connects filtering and automatic frequency control assembly 7.Software module is read the real part and the imaginary part of correlated results from hardware module in real work, calculate phase place and phase place is carried out filtering, calculates corresponding parameters for automatic frequency control.

Find that in actual use in order to save the hardware module resource, by staggering, first complex correlator 2 can be realized by identical hardware module circuit multiplexer with second complex correlator 3 on sequential.

As shown in Figure 2: the present invention adopts the joint detection results of data division in the TD-SCDMA structure of time slot, adopts the method for decision-feedback to estimate frequency deviation.At first, choosing S the character position among the DATA1 and the data of S character position among the DATA2 handles.Two parts data midfeather N1 DATA1 symbol and N2 DATA2 symbol.The data of DATA1 and DATA2 have all been passed through joint-detection, the interference that can effectively eliminate all the other code channels and face the sub-district with frequency.

Suppose S character position among the DATA1, on m the code channel in certain Common transport channel, the data (joint-detection demodulation output) of a s symbol are:

$I_{m,s}^1+j\×Q_{m,s}^1$ (m＝1，2，…，M，s＝1，2，…，S)

S among a DATA2 character position, on m the code channel in certain Common transport channel, the data (joint-detection demodulation output) of a s symbol are:

$I_{m,\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H2009100270993E0000012.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+j\&times;Q_{m,s}^2$ (m＝1，2，…，M，s＝1，2，…，S)

Then, joint detection results is carried out hard decision, promptly obtain respectively

With

Wherein, function sgn is for getting symbol manipulation, that is:

$\mathrm{sgn}\left(x\right)=\left\{\begin{array}{cc}1& ,x\&GreaterEqual;0\\ -1& ,x<0\end{array}\right.$

According to declaring the result firmly, remove the data-modulated information in this two segment data respectively, and do relevant treatment.For example, the last period data correlated results can be calculated as follows:

$\mathrm{Corr}1=\underset{s=1}{\overset{S}{\mathrm{\&Sigma;}}}\{(I_{m,s}^1+j\&times;Q_{m,s}^1)\&times;\mathrm{conj}(\mathrm{sgn}\left(I_{m,s}^1\right)+j\&times;\mathrm{sgn}\left(Q_{m,s}^1\right))\}$

$=\underset{s=1}{\overset{S}{\mathrm{\&Sigma;}}}\left[\right|I_{m,s}^1|+|Q_{m,s}^1\left|\right]+j\&times;[\mathrm{sgn}\left(I_{m,s}^1\right)\&times;\mathrm{sgn}\left(Q_{m,s}^1\right)\&times;\left(\right|Q_{m,s}^1|-|I_{m,s}^1\left|\right)]$

Similarly, can obtain the correlated results of back one piece of data by following formula:

$\mathrm{<figure-callout\; id="2"\; label="Corr"\; filenames="H2009100270993E0000012.png"\; state="\{\{state\}\}">Corr</figure-callout>}2=\underset{s=1}{\overset{S}{\mathrm{\&Sigma;}}}\{(I_{m,\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H2009100270993E0000012.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+j\&times;Q_{m,s}^2)\&times;\mathrm{conj}(\mathrm{sgn}\left(I_{m,s}^2\right)+j\&times;\mathrm{sgn}\left(Q_{m,s}^2\right))\}$

$=\underset{s=1}{\overset{S}{\mathrm{\&Sigma;}}}\left[\right|I_{m,\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H2009100270993E0000012.png"\; state="\{\{state\}\}">s</figure-callout>}}^2|+|Q_{m,\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H2009100270993E0000012.png"\; state="\{\{state\}\}">s</figure-callout>}}^2\left|\right]+j\&times;[\mathrm{sgn}\left(I_{m,s}^2\right)\&times;\mathrm{sgn}\left(Q_{m,s}^2\right)\&times;\left(\right|Q_{m,\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H2009100270993E0000012.png"\; state="\{\{state\}\}">s</figure-callout>}}^2|-|I_{m,\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H2009100270993E0000012.png"\; state="\{\{state\}\}">s</figure-callout>}}^2\left|\right)]$

Subsequently, calculating Corr1 is relevant with the conjugation of Corr2

Corr3＝conj(Corr1)×Corr2

Then the phase information of Corr3 is the phase place rotation of this section period.

Then, the self adaptation bit wide is adjusted, and adopts dsp software to read Corr3.During this period, consider that the width of bus is generally 16bit, it need limit real part, the imaginary part bit wide of Corr3.For guaranteeing the precision of subsequent calculations, hardware module output Corr3 result's number of significant digit should be wide as far as possible, and therefore output can not be taked the mode of fixed bit cut position.Thus, the present invention has provided the method that a kind of self adaptation bit wide is adjusted.Specifically, be real part imaginary part 26bit signed number with Corr3 result of calculation, the 16bit bus is output as example, then exports Output real part and imaginary part surely and is the 16bit signed number.

The Output sign bit is following to be got:

sgn(Re{output})＝sgn(Re{Corr3})

sgn(Im{output})＝sgn(Im{Corr3})。

The Output range value is following to be got: first figure place different with sign bit is w1 among the note Re{Corr3} bit from high to low, and first figure place different with sign bit is w2 among the note Im{Corr3} bit from high to low.Get w=max (w1, w2).If w 〉=15, [w:w-14] that get Corr3 real part imaginary part is as the part beyond the Output divided-by symbol position; If [14:0] then got as the part beyond the Output divided-by symbol position in w＜15.

At last, after software module reads Output, try to achieve the phase place deflection of every chip (chip) time correspondence

θ＝angle(Output)/((N1+N2+S)×SF+144)

Wherein SF represents spreading factor, carries out filtering by software module afterwards and asks automatic frequency control (AFC) Control Parameter to get final product.

Again further, (UE) is under the different mode when terminal, can utilize joint-detection (JD) result of different physical channels to carry out frequency offset estimating.Particularly:

(1) when terminal is in Cell searching (Cell Search) state, can utilizes the JD of broadcast channel (BCH) demodulation to export and carry out frequency offset estimating;

(2) be in the free time during (IDLE) pattern when terminal, still can utilize the JD of broadcast channel demodulation to export and carry out frequency offset estimating; Prerequisite is all to be distributed in time slot 0 (TS0) such as Page Indication Channel (PICH), paging channel common signal channels such as (PCH) to go up (note: although need not do decoding this moment to broadcast channel, 1/2 code channel on the TS0 is certain to participate in the JD task);

(3) when terminal is in connection (Connected) pattern, utilizes the JD of the minimum time slot of the Common transport channel (CCTrCH) of downward special physical channel (DPCH), minimum code channel to export and do frequency offset estimating; Why select minimum time slot, minimum code channel for use, unless be because be in discontinuous reception (DTX) state, otherwise certainly exist data.

By above-mentioned character express also in conjunction with the accompanying drawings as can be seen, behind employing the present invention,, adopt the method for decision-feedback to estimate frequency deviation by the joint detection results of data division in the TD-SCDMA structure of time slot.By comprising the joint-detection of facing the sub-district, eliminated the reception data that co-frequency cell interference and other users of this sub-district disturb like this, the skew of local frequency and network has been estimated more rationally with accurate with frequency.

Claims (10)

1. adopt the method for joint-detection calculating parameters for automatic frequency control, it is characterized in that may further comprise the steps: 1. step imports the reception result of joint-detection to hardware module;

The step 2. hardware module outcome symbol of choosing joint-detection is carried out the symbol hard decision;

Step is 3. to hard decision result and corresponding joint-detection data computation multiple correlation;

Step 4. to step 3. the gained result calculate multiple correlation once more;

Step 5. hardware module is carried out the adjustment of self adaptation bit wide to the result of secondary multiple correlation;

Step 6. software read step result is 5. carried out filtering, and controlled parameter converts.

2. the method for employing joint-detection calculating parameters for automatic frequency control according to claim 1 is characterized in that: the reception result of described step in 1. is with the mode serial input of symbol data streams.

3. the method for employing joint-detection calculating parameters for automatic frequency control according to claim 1 is characterized in that: the described step 2. real part and the imaginary part of middle symbol hard decision output signal is the real part of input signal and the symbolic information of imaginary part.

4. the method for employing joint-detection calculating parameters for automatic frequency control according to claim 1, it is characterized in that: described step is calculated multiple correlation in 3. for to S symbol in the first half symbol data of certain code channel of a TD-SCDMA time slot, and declares the result accordingly firmly and carries out multiple correlation and obtain Corr1 as a result; To the symbol of the S in the latter half symbol data, and declare the result accordingly firmly and carry out multiple correlation and obtain Corr2 as a result.

5. the method for employing joint-detection calculating parameters for automatic frequency control according to claim 1 is characterized in that: 4. described step is carried out multiple correlation to Corr1 and Corr2 and is obtained Corr3.

6. the method for employing joint-detection calculating parameters for automatic frequency control according to claim 1 is characterized in that: 5. described step is carried out the real part imaginary part that multiple correlation obtains Corr3 to Corr1 and Corr2 and is carried out the adjustment of self adaptation bit wide.

7. the method for employing joint-detection calculating parameters for automatic frequency control according to claim 1 is characterized in that: 6. described step reads hardware module completing steps result 5. by software, carries out filtering and convert obtaining parameters for automatic frequency control.

8. adopt the device of joint-detection calculating parameters for automatic frequency control, it is characterized in that: hardware module and software module, described hardware module comprises the hard decision device, the output of hard decision device is connected with the input of first complex correlator, the output of first complex correlator is connected with the input of second complex correlator, the output of second complex correlator connects the input of self adaptation bit wide adjuster, self adaptation bit wide regulator output is connected into software module, is connected with time schedule controller simultaneously on first complex correlator and second complex correlator.

9. the device of employing joint-detection calculating parameters for automatic frequency control according to claim 8 is characterized in that: described first complex correlator and second complex correlator on hardware module realizes by a multiplexing realization of complex correlator.

10. the device of employing joint-detection calculating parameters for automatic frequency control according to claim 8, it is characterized in that: described software module comprises the phase calculation assembly, self adaptation bit wide regulator output is connected into the input of computation module, and the output of computation module connects the input of filtering and automatic frequency control assembly.

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