CN1225928C - Signal locking indicating judging method and apparatus thereof - Google Patents

Abstract

The present invention relates to a method and a device thereof for the locking indicating judgment of a signal. The method comprises the steps: filtering processing is respectively carried out to the computed signal energy of a received signal and the energy of a noise signal; then, based on the signal energy and the energy of a noise signal after the filtering processing, the locking indicating judgment of the received signal is carried out. The device comprises a signal energy computation module (CM), a noise signal energy CM, a noise threshold CM and a comparator; additionally, first-order FIR (Finite Impulse Response) filters are respectively arranged between the signal energy CM and the comparator and between the noise signal energy CM and the noise threshold CM. Thereby, the present invention can effectively reduce the condition of the wrong locking indicating judgment of the signal in deep decline and effectively improve the accuracy of the locking indicating judgment of the signal.

Description

Method and device thereof that the semaphore lock indication is judged

Technical field

The present invention relates to wireless communication technology field, relate in particular to method and device thereof that a kind of semaphore lock indication is judged.

Background technology

In the mobile communication system, signal receive section need lock indication to the signal that receives and judge.The locking indication decision method that adopts at present is for calculating received signal energy and noise energy respectively, concrete computational methods as shown in Figure 1, after received signal carried out despreading and handle, be about to received signal and the local pseudo-random signal conjugate multiplication that produces, ask quadratic sum to handle again, the picked up signal energy, after simultaneously received signal being carried out the despreading processing, ask quadratic sum to handle again, obtain noise signal energy, and with the noise signal energy and the noise gate factor acquisition Noise gate limit value that multiplies each other; Then noise energy be multiply by the noise gate factor as noise gate.In the receiving branch of signal receive section, be provided with the locking indicating member, be used for the energy and the noise gate of receiving branch received signal are compared, if signal energy is less than noise gate, determine that then this road signal quality can't use, judge losing lock, promptly the signal of this receiving branch output does not participate in the MRC (high specific merging) of RAKE (receiver); If signal energy, determines then that this road signal quality can use greater than noise energy, judge locking, promptly the signal of this receiving branch output participates in the MRC of RAKE.

When signal is in when declining deeply, so-called decline is meant that signal is in transmission course, reason obstruction wireless receiving owing to transmission channel, thereby signal produces very big fluctuation, if still adopting this moment said method to lock indication judges, then because the signal energy of this moment is compared with noise gate and is more or less the same, and the locking indication that mistake will occur judges, thereby influenced the proper communication of mobile communication system.

Summary of the invention

The purpose of this invention is to provide method and device thereof that the indication of a kind of semaphore lock is judged, be in when declining deeply, the accuracy of judging based on the locking indication of transmit diversity to reduce signal.

The object of the present invention is achieved like this: the method that a kind of semaphore lock indication is judged comprises:

A, determine the signal energy and the noise signal energy of received signal respectively;

B, signal energy and noise signal energy are carried out single order FIR (limit for length's unit impulse response is arranged) filtering or smoothing processing respectively;

C, according to signal energy after the Filtering Processing and noise signal energy, carry out the locking indication of received signal and judge.

Described step a comprises:

A1, with received signal and local PN (pseudorandom) sign indicating number sequence conjugate multiplication, carry out the despreading of signal, to determine signal energy;

A2, received signal is postponed to handle, and determine noise signal energy according to the signal after postponing.

Described step a1 comprises:

A11, the baseband signal that will comprise I, Q two paths of data and local PN sign indicating number sequence conjugate multiplication are to obtain the data after two paths of signals I, the Q despreading;

The quadratic sum of the data after a12, calculating two paths of signals I, the Q despreading is as the signal energy after the despreading.

Described step a2 comprises:

A21, will comprise that the baseband signal of I, Q two paths of data postpones N sampled point;

A22, the I after will postponing, Q two paths of data and local PN sign indicating number sequence conjugate multiplication are to obtain the data after the despreading;

A23, calculate the I after the despreading, the quadratic sum of Q two paths of data, as the noise signal energy after the despreading.

The span of the sampled point number N of the described delay of step a21 is: between 20 samplings o'clock are counted to 800 samplings.

Described when signal energy and noise signal energy are carried out single order FIR Filtering Processing respectively, the value of filter factor is identical.

Described when signal energy and noise signal energy are carried out single order FIR Filtering Processing respectively, the value of the filter factor of filter (being filter factor) is between 0.5～0.995.

Described step c comprises:

C1, noise signal energy be multiply by the noise gate factor as noise gate;

C2, whether judge signal energy greater than noise gate, if, then judge locking, otherwise, judge losing lock.

A kind of semaphore lock indication decision maker, its structure comprises: signal energy computation module, the noise gate computing module and the comparator that link to each other with the noise signal energy computing module; The Noise gate limit value that signal energy that comparator is sent the signal energy computation module and noise gate computing module are sent relatively carries out the semaphore lock indication and judges; It is characterized in that also comprising:

First traffic filter and secondary signal filter, wherein: the signal energy of first traffic filter received signal energy computing module output, it is carried out exporting to comparator after the The disposal of gentle filter; The secondary signal filter receives the noise signal energy of noise signal energy computing module output, and it is carried out exporting to the noise gate computing module after the The disposal of gentle filter.

The received signal end of described noise signal energy computing module also increases and is provided with:

The signal delay submodule: receiving baseband signal postpones to handle, and exports to the noise signal energy computing module.

Described first traffic filter and secondary signal filter are single order FIR filter.

Described first traffic filter and secondary signal filter are same traffic filter.

By technique scheme as can be seen, the present invention adopts single order FIR filter that signal and noise energy are carried out smothing filtering, and adopted and to have asked noise energy with the method for local PN sign indicating number despreading behind receiving signal delayed certain sampling number, so signal energy and noise energy are very steady, can effectively resist decline.Therefore, the present invention can effectively reduce when declining deeply, and the situation of semaphore lock indication erroneous judgement has improved the accuracy that the semaphore lock indication is judged effectively.

Description of drawings

Fig. 1 is existing semaphore lock indication decision method schematic diagram;

Fig. 2 is an application schematic diagram of the present invention;

Fig. 3 is semaphore lock indication decision method of the present invention and schematic representation of apparatus;

Fig. 4 judges schematic diagram for comparator locking indication.

Embodiment

The signal receive section of mobile communication system is made up of many receiving branchs, be provided with locking indication identifying unit in each branch road, the device of the accuracy that raising semaphore lock indication of the present invention is judged promptly provides a kind of new locking indication identifying unit, its applied environment as shown in Figure 2, its structural principle comprises as shown in Figure 3:

The signal energy computation module: receiving baseband signal, calculate and determine to export comparator to after its signal energy; The signal energy computation module further comprises:

Signal despreading module: receiving baseband signal, carry out exporting signal to after despreading is handled and ask the quadratic sum module;

Signal is asked the quadratic sum module: the I that received signal despreading module is sent, Q two paths of data export filter to after asking quadratic sum to handle;

First traffic filter: receive the signal energy of asking the quadratic sum module to send, carry out exporting comparator to after the The disposal of gentle filter; What described first traffic filter adopted is single order FIR filter, and promptly the first single order FIR filter is used for signal energy is carried out smothing filtering.

The signal delay module: receiving baseband signal, postpone to handle, and the signal despreading module that comprised of output noise signal energy module.

Noise signal energy computing module, this module further comprise two parts:

Signal despreading module: the output of receiving signal delayed module through the baseband signal after postponing to handle, with itself and local PN sign indicating number sequence conjugate multiplication, carry out exporting to signal after despreading is handled and ask the quadratic sum module;

Signal is asked the quadratic sum module: the despread data of received signal despreading module output, and the I, the Q two paths of data that obtain are handled in despreading asked quadratic sum to handle, obtain to export to filter after the noise signal energy.

The secondary signal filter: received signal is asked the noise signal energy of quadratic sum module output, it is carried out smothing filtering, and will export to the noise gate computing module through the noise signal energy of Filtering Processing;

The secondary signal filter can adopt single order FIR filter, i.e. filtering factor (the being filter coefficient) value of the filter in the second single order FIR filter, and its filtering factor value and the signal energy computation module is identical;

The described second single order FIR filter, the signal that is connected in the noise signal energy computing module is asked between gentle module and the noise gate computing module, exports the noise gate computing module to after signal being asked the noise signal energy smothing filtering of quadratic sum module output.

The noise gate computing module: the noise signal energy after the process of receiving filter (being single order FIR filter) output is level and smooth, and it be multiply by the noise gate factor obtain the Noise gate limit value, export to comparator again.

Comparator: the signal energy that received signal energy computing module is sent, reach the Noise gate limit value that the noise gate computing module is sent, carry out the semaphore lock indication according to the size of signal energy and Noise gate limit value and judge, and the output lock indication signal.

First traffic filter described in the said apparatus provided by the invention and secondary signal filter also can adopt same traffic filter, carry out the realization of corresponding function.

Based on the semaphore lock indication decision maker that the invention described above provided, the concrete enforcement of method of the present invention is described below referring to Fig. 3:

Usually RAKE receiver is made up of many receiving branchs.A locking indicating module all can be arranged in each receiving branch

Step 1: after signal process radio frequency that antenna receives and baseband signal processing module are handled, become baseband signal; Baseband signal is sent to the locking indication identifying unit of receiving branch;

Step 2: baseband signal at first with local PN sign indicating number sequence conjugate multiplication, finish the despreading of signal;

$\mathrm{symbol}\_i\left(k\right)+j*\mathrm{symbol}\_q\left(k\right)=\underset{k}{\mathrm{\Σ}}\{\mathrm{chip}\_i\left(k\right)+j*\mathrm{chip}\_q\left(k\right)\}*\{\mathrm{PN}\_i\left(k\right)-j*\mathrm{PN}\_q\left(k\right)\}$

$\mathrm{symbol}\_i\left(k\right)=\underset{k}{\mathrm{\Σ}}\mathrm{chip}\_i\left(k\right)*\mathrm{PN}\_i\left(k\right)+\mathrm{chip}\_q\left(k\right)*\mathrm{PN}\_q\left(k\right)$

$\mathrm{symbol}\_q\left(k\right)=\underset{k}{\mathrm{\Σ}}\mathrm{chip}\_q\left(k\right)*\mathrm{PN}\_i\left(k\right)-\mathrm{chip}\_i\left(k\right)*\mathrm{PN}\_q\left(k\right)$

Wherein: chip_i (k) and chip_q (k) are respectively I, the Q two paths of data that received signal comprises, PN_i (k), PN_q (k) are local PN sign indicating number sequence, and symbol_i (k) and symbol_q (k) are respectively the I that received signal comprises, the data after the despreading of Q two paths of data;

Step 3: the I after the calculating despreading, the quadratic sum of Q two paths of data, as the signal energy of received signal, that is:

signal_pwr＝symbol_i ²(k)+symbol_q ²(k)

Wherein: signal_pwr represents signal energy;

Step 4: signal energy is made single order FIR Filtering Processing, that is:

out_pwr(0)＝signal_pwr(0)

out_pwr(1)＝alfa*out_pwr(0)+(1-alfa)*signal_pwr(1)

out_pwr(2)＝alfa*out_pwr(1)+(1-alfa)*signal_pwr(2)

.....

Wherein: alfa is a single order FIR filter coefficient, and the alfa value is between 0.5 to 0.995 usually;

Step 5: receive data and at first postpone N sampled point;

The span of N 20 samplings count count to 800 samplings between;

Step 6: the PN sign indicating number sequence of the data utilization this locality after will postponing is carried out despreading and is handled I, Q two paths of data after the acquisition despreading;

Step 7: the I after the calculating despreading, the quadratic sum of Q two paths of data, as the noise signal energy of received signal;

Step 8: noise signal energy is made single order FIR Filtering Processing;

Wherein: noise signal energy is made single order FIR filter filtering factor value and signal energy to be made an attached FIR filter filtering factor value identical;

Step 9: send into comparator as the Noise gate limit value after the noise signal energy after inciting somebody to action smoothly multiply by the noise gate factor;

Step 10: the size of comparator comparison signal energy and noise gate, deterministic process as shown in Figure 4, if signal energy less than noise gate, is then judged losing lock, comparator output losing lock index signal " 0 "; If signal energy greater than noise gate, is then judged locking, comparator output lock indication signal " 1 ".

So far, the processing procedure of the method that semaphore lock indication of the present invention is judged finishes, and enters other corresponding processing procedure in the mobile communication system, may further comprise the steps:

Step 11: the locking indicating status of each receiving branch, i.e. the lock indication signal or the losing lock index signal of comparator output all are fed in the MRC module; According to the locking indicating status of each receiving branch, judge whether the dateout of each receiving branch participates in merging; If the locking indicating status of receiving branch is locking, then the dateout of this receiving branch participates in merging; If the locking indicating status of receiving branch is a losing lock, then the dateout of this receiving branch does not participate in merging;

Step 12: the data after the merging are admitted in the data extraction module, extract the data bit of the correspondence of received signal;

Step 13: the data bit that extracts is admitted to decoding module; After decoding finishes, the output original data bits.

Claims (12)

1, a kind of method of semaphore lock indication judgement is characterized in that comprising:

A, determine the signal energy and the noise signal energy of received signal respectively;

B, signal energy and noise signal energy are carried out single order FIR (limit for length's unit impulse response is arranged) filtering or smoothing processing respectively;

C, according to signal energy after the Filtering Processing and noise signal energy, carry out the locking indication of received signal and judge.

2, the method for semaphore lock indication judgement according to claim 1 is characterized in that described step a comprises:

A1, with received signal and local PN (pseudorandom) sign indicating number sequence conjugate multiplication, carry out the despreading of signal, to determine signal energy;

A2, received signal is postponed to handle, and determine noise signal energy according to the signal after postponing.

3, the method for semaphore lock indication judgement according to claim 2 is characterized in that described step a1 comprises:

A11, the baseband signal that will comprise I, Q two paths of data and local PN sign indicating number sequence conjugate multiplication are to obtain the data after two paths of signals I, the Q despreading;

The quadratic sum of the data after a12, calculating two paths of signals I, the Q despreading is as the signal energy after the despreading.

4, according to the method for claim 2 or 3 described semaphore lock indication judgements, it is characterized in that described step a2 comprises:

A21, will comprise that the baseband signal of I, Q two paths of data postpones N sampled point;

A22, the I after will postponing, Q two paths of data and local PN sign indicating number sequence conjugate multiplication are to obtain the data after the despreading;

A23, calculate the I after the despreading, the quadratic sum of Q two paths of data, as the noise signal energy after the despreading.

5, the method judged of semaphore lock according to claim 4 indication is characterized in that the span of the sampled point number N of the described delay of step a21 is: between 20 samplings o'clock are counted to 800 samplings.

6, the method judged of semaphore lock according to claim 1 indication is characterized in that: described when signal energy and noise signal energy are carried out single order FIR Filtering Processing respectively, the value of filter factor is identical.

7, the method for semaphore lock indication judgement according to claim 6, it is characterized in that: described when signal energy and noise signal energy are carried out single order FIR Filtering Processing respectively, the value of the filter factor of filter (being filter factor) is between 0.5 to 0.995.

8, the method for semaphore lock indication judgement according to claim 1 is characterized in that described step c comprises:

C1, noise signal energy be multiply by the noise gate factor as noise gate;

C2, whether judge signal energy greater than noise gate, if, then judge locking, otherwise, judge losing lock.

9, a kind of semaphore lock indication decision maker, its structure comprises: signal energy computation module, the noise gate computing module and the comparator that link to each other with the noise signal energy computing module; The Noise gate limit value that signal energy that comparator is sent the signal energy computation module and noise gate computing module are sent relatively carries out the semaphore lock indication and judges; It is characterized in that:

Also comprise first traffic filter, secondary signal filter, wherein the signal energy of first traffic filter received signal energy computing module output carries out it to export to comparator after The disposal of gentle filter; The secondary signal filter receives the noise signal energy of noise signal energy computing module output, and it is carried out exporting to the noise gate computing module after the The disposal of gentle filter.

10, semaphore lock indication decision maker according to claim 9, the received signal end that it is characterized in that described noise signal energy computing module also increases and is provided with the signal delay submodule, signal delay submodule receiving baseband signal, postpone to handle, and export to the noise signal energy computing module.

11, according to claim 9 or 10 described semaphore lock indication decision makers, it is characterized in that described first traffic filter and secondary signal filter all are single order FIR filter.

12, according to claim 9 or 10 described semaphore lock indication decision makers, it is characterized in that described first traffic filter and secondary signal filter use same traffic filter.

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