CN102883411A - Frequency point scanning method, processor, device and system for LTE (long term evolution) - Google Patents

Abstract

The embodiment of the invention discloses a frequency point scanning method, processor, device and system for LTE (long term evolution). The frequency point scanning method comprises the steps of acquiring power of subcarriers in a frequency band, and calculating the average power of the subcarriers in the frequency band by taking a resource block as a unit; determining a candidate frequency point set in a candidate frequency point region according to a preset step, wherein the candidate frequency point region comprises the resource blocks meeting a preset number requirement, and the average power of the subcarriers in the frequency band of the resource blocks is more than a judgment threshold; and eliminating the frequency points, which do not meet the power detection conditions on principle synchronous signs PSS and secondary synchronous signs SSS, in the candidate frequency point set, and demodulating failed false frequency points by demodulating a physical broadcast channel (PBCH) to obtain frequency point scanning results. The frequency point scanning method overcomes the defect of long time for scanning the frequency points in a broad band one by one in the prior art, and can obtain the frequency point scanning results in the eligible candidate frequency point region and eliminate the influence of other dynamic allocation channels on power, so that the accuracy of the candidate frequency points is enhanced.

Description

A kind of method for scanning frequency points towards LTE, processor, device and system

Technical field

The present invention relates to communication technical field, more particularly, relate to a kind of method for scanning frequency points towards LTE, processor, device and system.

Background technology

In the mobile communication system, the frequency point scanning of user terminal UE refers to that this UE is within start a period of time or when losing the network coverage, and under do not prestore residential quarter or search prestore the situation of residential quarter failure, attempt in it accepts band limits, searching for the activity of effective Serving cell working frequency points.

Existing method for scanning frequency points is the received power of measuring each possibility frequency, and possible frequency is carried out the descending of power measurement values, thereby carries out search of initial zone according to the descending mode of power measurement values.

There is following shortcoming at least in existing method for scanning frequency points towards LTE: because the channel allocation in the LTE communication system only has PSS, SSS, PBCH(is in LTE, UE utilizes main synchronizing symbol PSS and auxiliary synchronizing symbol SSS and demodulation physical layer broadcast channel PBCH to obtain the system information that comprises system bandwidth) and a few channel such as reference symbol RS send at fixed time, the equal dynamic assignment of other channels, therefore whether be that other channels carry out channel allocation and produce greatly inaccurate that power measurement sorts for the power measurement impact, simultaneously, existing method for scanning frequency points needs for various bandwidth frequency point scanning one by one, thereby has long problem of frequency point scanning time.

Summary of the invention

In view of this, the invention provides a kind of method for scanning frequency points towards LTE, processor, device and system, with the technique effect of realizing improving the scanning result accuracy and shortening sweep time.

The method for scanning frequency points of a kind of LTE comprises:

Obtain interior each sub-carrier power of frequency band and the calculating frequency band subcarrier average power take Resource Block as unit;

According to default step-length, in candidate's frequency zone, determine candidate's frequency point sets, described candidate's frequency district inclusion has the Resource Block that satisfies a default said conditions, and the frequency band subcarrier average power of described Resource Block is greater than decision threshold;

Reject the frequency that does not meet main synchronizing symbol PSS and auxiliary synchronizing symbol SSS power detection condition in described candidate's frequency point sets, and the alias point by demodulation physical layer broadcast channel PBCH demodulation failure, the frequency point scanning result obtained.

Alternatively, obtain in the frequency band each sub-carrier power and calculate frequency band subcarrier average power take Resource Block as unit and comprise:

Receive time-domain signal according to default center frequency point, and forward described time-domain signal to frequency domain;

The power of each subcarrier in frequency domain calculates frequency band, and within the default cumulative time, the power of each subcarrier is added up, cumulative power obtained;

Take Resource Block as unit to described cumulative power calculation average power.

Alternatively, according to default step-length, determine that in candidate's frequency zone candidate's frequency point sets comprises:

Judge whether current frequency zone includes at least 6 continuous resource pieces, and the frequency band subcarrier average power of described Resource Block is more than or equal to default decision threshold, if so, then current frequency zone is candidate's frequency zone;

Take 100KHz as step-length, each 3 average power that resource is fast about calculating in described candidate's frequency zone by arranging from big to small, obtain candidate's frequency point sets

Alternatively, also comprise and detect main synchronizing symbol PSS, comprising:

It is relevant to utilize the local sequence of described PSS and the time-domain signal of reception to do time domain with preset interval time to each candidate's frequency in candidate's frequency point sets, obtains a plurality of related powers;

Search maximal correlation power P SS_Max_Power in a plurality of related powers, and calculate average related power PSS_Ave_Power in a plurality of related powers, when

$\frac{\mathrm{PSS}\_\mathrm{Max}\_\mathrm{Power}}{\mathrm{PSS}\_\mathrm{Ave}\_\mathrm{Power}}<\mathrm{PSS}\_\mathrm{Threshold}$ The time, candidate's frequency that then this related power is corresponding is disallowable;

Wherein, PSS_Threshold is the decision threshold of default PSS power detection.

Alternatively, also comprise and detect auxiliary synchronous signals SSS, comprising:

Extract subcarrier corresponding to described SSS at frequency domain, described subcarrier and SSS this locality sequence are done relevant, obtain a plurality of related powers;

Search maximal correlation power SSS_Max_Power in a plurality of related powers, and calculate average related power SSS_Ave_Power, when

$\frac{\mathrm{SSS}\_\mathrm{Max}\_\mathrm{Power}}{\mathrm{SSS}\_\mathrm{Ave}\_\mathrm{Power}}<\mathrm{SSS}\_\mathrm{Threshold}$ The time, candidate's frequency that then this related power is corresponding is disallowable;

Described SSS_Threshold is the decision threshold of default SSS power detection.

Alternatively, also comprise demodulation judgement candidate frequency, comprising:

According to the residential quarter ID that obtains and frame timing demodulation PBCH, if the demodulation failure, candidate's frequency that then this related power is corresponding is disallowable.

Alternatively, comprise that also the frequency band occupancy does not repeat to judge:

Whether the candidate's frequency that extracts one by one in described candidate's frequency point sets overlaps with as a result frequency comparison of described frequency point scanning frequency band, and respective frequencies and bandwidth are respectively: f _mAnd f _n, bandwidth is respectively BW _mAnd BW _n, when

$|f_m-f_n|\&le;\frac{B{W}_m+{\mathrm{<figure-callout\; id="2"\; label="BW\; n"\; filenames="HDA00002273352100011.png,HDA00002273352100012.png"\; state="\{\{state\}\}">BW</figure-callout>}}_n}{2}$ The time, remove this candidate's frequency.

A kind of frequency point scanning processor towards LTE comprises:

Frequency band subcarrier average power is calculated module, is used for obtaining interior each sub-carrier power of frequency band and the calculating frequency band subcarrier average power take Resource Block as unit;

Candidate's frequency determination module is used for according to default step-length, determines candidate's frequency point sets in candidate's frequency zone, and described candidate's frequency district inclusion has the Resource Block that satisfies a default said conditions, and the frequency band subcarrier average power of described Resource Block is greater than decision threshold;

Frequency is rejected module, is used for rejecting the frequency that described candidate's frequency point sets does not meet main synchronizing symbol PSS and auxiliary synchronizing symbol SSS power detection condition, and the alias point by demodulation physical layer broadcast channel PBCH demodulation failure, obtains the frequency point scanning result.

Alternatively, described frequency band subcarrier average power calculating module comprises:

The frequency domain modular converter is used for receiving time-domain signal according to default center frequency point, and forwards described time-domain signal to frequency domain;

Cumulative power computation module is used for the power of each subcarrier in frequency domain calculates frequency band, and within the default cumulative time power of each subcarrier is added up, and obtains cumulative power;

Average power is calculated module, is used for take Resource Block as unit described cumulative power calculation average power.

Alternatively, described candidate's frequency determination module comprises:

Candidate's frequency zone determination module is used for judging whether current frequency zone includes at least 6 continuous resource pieces, and the frequency band subcarrier average power of described Resource Block is more than or equal to default decision threshold, and if so, then current frequency zone is that candidate's frequency is regional;

Order module is used for take 100KHz as step-length, and each 3 average power that resource is fast about calculating in described candidate's frequency zone by arranging from big to small, obtain candidate's frequency point sets

Alternatively, also comprise: main synchronizing symbol PSS detection module, it is relevant to be used for utilizing the local sequence of described PSS and the time-domain signal of reception to do time domain with preset interval time to each candidate's frequency of candidate's frequency point sets, obtains a plurality of related powers;

Search maximal correlation power P SS_Max_Power in a plurality of related powers, and calculate average related power PSS_Ave_Power in a plurality of related powers, when

$\frac{\mathrm{PSS}\_\mathrm{Max}\_\mathrm{Power}}{\mathrm{PSS}\_\mathrm{Ave}\_\mathrm{Power}}<\mathrm{PSS}\_\mathrm{Threshold}$ The time, candidate's frequency that then this related power is corresponding is disallowable;

Wherein, PSS_Threshold is the decision threshold of default PSS power detection.

Alternatively, also comprise: auxiliary synchronous signals SSS detection module, be used for extracting subcarrier corresponding to described SSS at frequency domain, described subcarrier and SSS this locality sequence are done relevant, obtain a plurality of related powers;

Search maximal correlation power SSS_Max_Power in a plurality of related powers, and calculate average related power SSS_Ave_Power, when

$\frac{\mathrm{SSS}\_\mathrm{Max}\_\mathrm{Power}}{\mathrm{SSS}\_\mathrm{Ave}\_\mathrm{Power}}<\mathrm{SSS}\_\mathrm{Threshold}$ The time, candidate's frequency that then this related power is corresponding is disallowable;

Described SSS_Threshold is the decision threshold of default SSS power detection.

Alternatively, also comprise: candidate's frequency demodulation determination module is used for:

According to the residential quarter ID that obtains and frame timing demodulation PBCH, if the demodulation failure, candidate's frequency that then this related power is corresponding is disallowable.

Whether alternatively, also comprise: can not reject module by frequency, overlap with as a result frequency comparison of described frequency point scanning frequency band for the candidate's frequency that extracts one by one described candidate's frequency point sets, respective frequencies and bandwidth are respectively: f _mAnd f _n, bandwidth is respectively BW _mAnd BW _n, when

$|f_m-f_n|\&le;\frac{B{W}_m+{\mathrm{<figure-callout\; id="2"\; label="BW\; n"\; filenames="HDA00002273352100011.png,HDA00002273352100012.png"\; state="\{\{state\}\}">BW</figure-callout>}}_n}{2}$ The time, remove this candidate's frequency.

A kind of frequency point scanning device towards LTE comprises above-mentioned frequency point scanning processor towards LTE, and memory, and described scanning processor is connected with memory by interface.

A kind of frequency point scanning system towards LTE comprises: comprise above-mentioned frequency point scanning device towards LTE.

Can find out from above-mentioned technical scheme, the method for scanning frequency points towards LTE in the embodiment of the invention averages power calculation take Resource Block as unit, and will meet pre-conditioned Resource Block composition candidate frequency zone, possible sweep limits is drawn a circle to approve in candidate's frequency zone, thereby overcome prior art scans length consuming time one by one to the frequency in the broadband shortcoming, in to described candidate's frequency zone, do not meet for main synchronizing symbol PSS and auxiliary synchronizing symbol SSS power detection condition, and frequency that can not demodulation physical layer broadcast channel PBCH is rejected, thereby in qualified candidate's frequency zone, obtain the frequency point scanning result, and the channel of getting rid of other dynamic assignment impact that power detection is caused, improved the accuracy of candidate's frequency, and calculate average power take described Resource Block as unit, owing to include reference symbol in the Resource Block, guaranteed the validity that candidate's frequency point sets is chosen.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, the below will do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art, apparently, accompanying drawing in the following describes only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.

Fig. 1 is PSS, SSS and PBCH time-domain position schematic diagram under the disclosed a kind of existing fdd mode of the embodiment of the invention;

Fig. 2 is PSS, SSS and PBCH time-domain position schematic diagram under the disclosed a kind of existing TDD pattern of the embodiment of the invention;

Fig. 3 is the disclosed a kind of method for scanning frequency points midband subcarrier average power method flow diagram towards LTE of the embodiment of the invention;

Fig. 4 is the disclosed a kind of method for scanning frequency points midband subcarrier average power method flow diagram towards LTE of the embodiment of the invention;

Fig. 5 is the disclosed a kind of candidate's frequency point sets method flow diagram of determining in the method for scanning frequency points of LTE of the embodiment of the invention;

Fig. 6 is the disclosed a kind of method for scanning frequency points flow chart towards LTE of further embodiment of this invention;

Fig. 7 is the disclosed a kind of frequency point scanning processor structure schematic diagram towards LTE of the embodiment of the invention;

Fig. 8 is that the disclosed a kind of frequency point scanning processor midband subcarrier average power towards LTE of the embodiment of the invention is calculated the modular structure schematic diagram;

Fig. 9 be the embodiment of the invention disclosed a kind of in the frequency point scanning processor of LTE candidate's frequency determination module structural representation;

Figure 10 is disclosed another the frequency point scanning processor structure schematic diagram towards LTE of the embodiment of the invention;

Figure 11 is the disclosed a kind of frequency point scanning apparatus structure schematic diagram towards LTE of the embodiment of the invention;

Figure 12 is the disclosed a kind of frequency point scanning system configuration schematic diagram towards LTE of the embodiment of the invention;

Figure 13 is the disclosed a kind of frequency point scanning system configuration schematic diagram towards LTE of further embodiment of this invention;

Figure 14 is the disclosed a kind of frequency point scanning system configuration schematic diagram towards LTE of further embodiment of this invention.

Embodiment

For quote and know for the purpose of, the technical term that hereinafter uses, write a Chinese character in simplified form or abridge and be summarized as follows:

LTE:Long Term Evolution, Long Term Evolution;

UE:User Equipment, user terminal;

PSS:Primary Synchronization Signal, main synchronizing symbol;

SSS:Secondary Synchronization Signal, auxiliary synchronizing symbol;

PBCH:Physical Broadcast Channel, physical layer broadcast channel;

RS:Reference Symbol, reference symbol;

Slot: time slot;

OFDM:Orthogonal Frequency Division Multiplexing, OFDM;

RB:Resource Block, Resource Block.

FDD:Frequency Division Duplex, Frequency Division Duplexing (FDD)

TDD, Time Division Duplex, time division duplex;

FFT:Fast Fourier Transformation, fast Fourier transform;

Nid:Network Identification, NID.

Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that obtains under the creative work prerequisite.

There are two kinds of communication patterns of FDD and time division duplex in existing LTE system;

Frame structure under the fdd mode comprises the radio frames take 10ms as unit, and each radio frames comprises 20 0.5ms time slots, and two adjacent time-slots are a 1ms subframe, and the time slot label is Slot0-Slot19;

Frame structure under the tdd mode is that each 10ms is the field that the radio frames of unit comprises two 5ms, each field comprises the subframe (label 0-9) of 5 1ms, the second subframe of each field is special subframe, all the other each conventional subframes comprise the time slot of two 0.5ms, label is respectively Slot 2*i, Slot2*i+1.

For fdd mode, described PSS, SSS and PBCH time-domain position as shown in Figure 1, PSS is at last OFDM symbol of Slot0 and Slot10, SSS is at the penult OFDM of Slot0 and Slot10 symbol, PBCH is at front 4 OFDM symbols of Slot1;

At tdd mode, the time-domain position of described PSS, SSS and PBCH as shown in Figure 2, PSS is at the 3rd the OFDM symbol of Slot2 and Slot12, SSS is at last OFDM symbol of Slot1 and Slot11, PBCH is at front 4 OFDM symbols of Slot1.And PSS, SSS and the PBCH frequency domain position under FDD and tdd mode is 6 Resource Block RB in bandwidth centre position.

Traditional method for scanning frequency points is the received power to each possibility frequency of measurement in the possible bandwidth, and power measurement values is carried out descending, then carries out search of initial zone by the ranking results order.There is following problem in this method:

Measurement result is inaccurate:

Except PSS, a few channels such as SSS, PBCH and reference symbol RS are beyond fixed time sends in the LTE system, and other channels all are dynamic assignment.And the channel that sends of these several fixed times to account for the ratio of gross power very little, so whether other channels divide pairing power measurement result impact very large.

Measuring Time is long:

At first, when doing frequency point scanning, do not know system bandwidth, therefore need to attempt different bandwidth, can prolong the time of frequency point scanning; Take tdd mode as example, when doing frequency point scanning, do not know the uplink-downlink configuration of system, so each frequency power measurement continues to want at least 5ms, guarantee can measure the power of downstream signal; And the width of a frequency band may be very large, is 100MHz such as the total bandwidth of Band40, if do power measurement by each frequency, and each frequency 5ms, a power is measured just needs 5s.

The embodiment of the invention discloses a kind of method for scanning frequency points towards LTE, processor, device and system, with the technique effect of realizing improving the scanning result accuracy and shortening sweep time.

Fig. 3 shows a kind of method for scanning frequency points towards LTE, comprising:

S301: obtain interior each sub-carrier power of frequency band and the calculating frequency band subcarrier average power take Resource Block as unit;

As shown in Figure 4,

S401: receive time-domain signal according to default center frequency point, and forward described time-domain signal to frequency domain;

The LTE system uses 2048 FFT, and subcarrier spacing is 15kHz, and therefore each maximum analysis bandwidth is 15KHz*2048=30.72MHz, supposes that the frequency band that will scan is from F ₁To F ₂MHz, the number of times that then needs to analyze is

The center frequency point that arranges for the i time is:

Forward the time-domain signal that receives to frequency domain, obtain the signal of 2048 subcarriers, it should be noted that the FFT the possibility of result out of last setting exceeds F ₁To F ₂Scope, the parton carrier wave that exceeds is ignored.

S402: the power of each subcarrier in frequency domain calculates frequency band, and within the default cumulative time, the power of each subcarrier is added up, obtain cumulative power;

Sub-carrier power is added up, and to fdd mode, the minimum cumulative time is 1ms, and to tdd mode, the minimum cumulative time is 5ms, and as required, the cumulative time can be longer.

The result who finally obtains is that F1 is to the cumulative performance number of interior all subcarriers of F2 Wherein

Total subcarrier number.

S403: take Resource Block as unit to described cumulative power calculation average power.

Calculate average power with Resource Block (hereinafter to be referred as RB, a RB comprises 12 subcarriers) for unit, and judge that whether this average power is more than or equal to default RSSI decision threshold RSSI_Threshold.The reason of adjudicating take RB as unit is that no matter whether this RB distributes to Traffic Channel, necessarily includes the RS symbol, can guarantee the validity of adjudicating.

S302: according to default step-length, determine candidate's frequency point sets in candidate's frequency zone, described candidate's frequency district inclusion has the Resource Block that satisfies a default said conditions, and the frequency band subcarrier average power of described Resource Block is greater than decision threshold;

As shown in Figure 5:

S501: it is pre-conditioned to judge whether current region meets:

Judge whether current frequency zone includes at least 6 continuous resource pieces, and the frequency band subcarrier average power of described Resource Block is more than or equal to default decision threshold, if so, then current frequency zone is candidate's frequency zone;

Surpass continuously 6 RB(6 RB correspondence 1.4M bandwidth) the zone think the zone of candidate's frequency, otherwise think and be not.Do like this and can exclude some zone that disturbed by the arrowband, reduce the time of frequency point scanning.

S502: take 100KHz as step-length, each 3 average power that resource is fast about calculating in described candidate's frequency zone by arranging from big to small, obtain candidate's frequency point sets

Carry out further on average for the average power in the Resource Block, improve the exact value of the frequency power in this candidate's frequency zone, for ordering is done accurately with reference to preparing.

S303: reject the frequency that does not meet main synchronizing symbol PSS and auxiliary synchronizing symbol SSS power detection condition in described candidate's frequency point sets, and the alias point by demodulation physical layer broadcast channel PBCH demodulation failure, obtain the frequency point scanning result.

As above analyze as can be known, main synchronizing symbol PSS and auxiliary synchronizing symbol SSS and physical layer broadcast channel PBCH need the fixed allocation channel, by three kinds of parameters are carried out power detection, get rid of the impact that the channel of other dynamic assignment causes power detection, can find reliably whether this frequency is available.

Above-described embodiment averages power calculation take Resource Block as unit, and will meet pre-conditioned Resource Block composition candidate frequency zone, possible sweep limits is drawn a circle to approve in candidate's frequency zone, thereby overcome the shortcoming that prior art scans one by one to the frequency in the broadband, in to described candidate's frequency zone, do not meet for main synchronizing symbol PSS and auxiliary synchronizing symbol SSS power detection condition, and frequency that can not demodulation physical layer broadcast channel PBCH is rejected, thereby obtain the frequency point scanning result in possible frequency zone, and the channel of getting rid of other dynamic assignment has improved the accuracy of candidate's frequency to the impact that power detection causes.

Fig. 6 shows the method for scanning frequency points of another LTE, comprising:

S601: obtain interior each sub-carrier power of frequency band and the calculating frequency band subcarrier average power take Resource Block as unit;

S602: according to default step-length, determine candidate's frequency point sets in candidate's frequency zone, described candidate's frequency district inclusion has the Resource Block that satisfies a default said conditions, and the frequency band subcarrier average power of described Resource Block is greater than decision threshold;

S603: judge whether each frequency in candidate's frequency point sets meets PSS power detection condition:

It is relevant to utilize the local sequence of described PSS and the time-domain signal of reception to do time domain with preset interval time to each candidate's frequency in candidate's frequency point sets, obtains a plurality of related powers;

Described time domain is relevant can select following mode to realize:

Utilizing 3 local PSS sequences and receive signal in the 5ms(preset interval time, also is the repetition period of PSS simultaneously, is 9600 sampled points under the 1.92M sampling rate) in the scope as follows (1) do and slide relevantly, obtain correlated results.

$\mathrm{PSS}\_\mathrm{Corr}\_\mathrm{Result}(m,n)=\underset{i=0}{\overset{127}{\mathrm{\&Sigma;}}}\mathrm{Local}\_P{\mathrm{SS}}^{*}(m,i)*\mathrm{Rx}\_\mathrm{Data}(n+i)---\left(1\right)$

Calculate the related power module, (2) calculate related power as follows.

PSS_Corr_Power(m,n)=||PSS_Corr_Result(m,n)|| ² （2）

Search maximal correlation power P SS_Max_Power in a plurality of related powers, and calculate average related power PSS_Ave_Power in a plurality of related powers, when

$\frac{\mathrm{PSS}\_\mathrm{Max}\_\mathrm{Power}}{\mathrm{PSS}\_\mathrm{Ave}\_\mathrm{Power}}\&GreaterEqual;\mathrm{PSS}\_\mathrm{Threshold}$ The time, execution in step S604; Otherwise candidate's frequency that this related power is corresponding is disallowable, and returns S603;

More preferably, in order to improve the detection accuracy, need to calculate a plurality of 5ms(Preset Times interval) related power, add up (3) then as follows.

PSS_Corr_Power_Acc(m,n)=PSS_Corr_Power_Acc(m,n)+PSS_Corr_Power(m,n)（3）

Utilize 3 local PSS sequences to calculate related power, then from 3*9600 relevant cumulative power, search out M maximum peak value, record each peak value corresponding second network identification code Nid2 and position, simultaneously as follows (4) calculating of above-mentioned average related power:

$\mathrm{PSS}\_\mathrm{Ave}\_\mathrm{Power}=(\underset{m=0}{\overset{2}{\mathrm{\&Sigma;}}}\underset{n=0}{\overset{9599}{\mathrm{\&Sigma;}}}\mathrm{PSS}\_\mathrm{Corr}\_\mathrm{Power}\_\mathrm{Acc}(m,n))/(3*9600)---\left(4\right)$

Wherein, PSS_Threshold is the decision threshold of default PSS power detection.

S604: judge whether each frequency in candidate's frequency point sets meets SSS power detection condition:

Extract subcarrier corresponding to described SSS at frequency domain, described subcarrier and SSS this locality sequence are done relevant, obtain a plurality of related powers;

Above-mentioned steps can realize in the following way:

According to the PSS peak, calculate the position at SSS symbol place, then the SSS symbol is FFT and calculates, obtain the frequency-region signal of SSS symbol;

From described frequency-region signal, extract subcarrier SSS_Sc (i) corresponding to SSS, (i=0 ..., 61);

Utilize 336 local sequence Local_SSS (m, i) (m=0 ..., 335, i=0 ..., 61) respectively with the SSS subcarrier that extracts by formula (5) do relevantly, obtain 336 correlated results.

$\mathrm{SSS}\_\mathrm{Corr}\_\mathrm{Result}\left(m\right)=\underset{i=0}{\overset{61}{\mathrm{\&Sigma;}}}\mathrm{Local}\_\mathrm{SS}{S}^{*}(m,i)*\mathrm{SSS}\_\mathrm{Sc}\left(i\right)---\left(5\right)$

Calculate the related power module, by formula (6) calculate related power.

SSS_Corr_Power(m)=||SSS_Corr_Result(m)|| ² （6）

Search maximal correlation power SSS_Max_Power in a plurality of related powers, and calculate average related power SSS_Ave_Power, when

$\frac{\mathrm{SSS}\_\mathrm{Max}\_\mathrm{Power}}{\mathrm{SSS}\_\mathrm{Ave}\_\mathrm{Power}}\&GreaterEqual;\mathrm{SSS}\_\mathrm{Threshold}$ The time, execution in step S605; Otherwise candidate's frequency that this related power is corresponding is disallowable, and returns S603;

The calculating of above-mentioned average related power can be carried out in the following way:

In order to improve the detection accuracy, need to calculate the related power of a plurality of 5ms, add up (7) then as follows.

SSS_Corr_Power_Acc(m)=SSS_Corr_Power_Acc(m)+SSS_Corr_Power(m)（7）

From 336 relevant cumulative power, search out N maximum peak value, record first network identification code Nid1 corresponding to each peak value and front and back 5ms sign.Press simultaneously formula (8) and calculate average related power.

$\mathrm{SSS}\_\mathrm{Ave}\_\mathrm{Power}=(\underset{m=0}{\overset{334}{\mathrm{\&Sigma;}}}\mathrm{SSS}\_\mathrm{Corr}\_\mathrm{Power}\_\mathrm{Acc}\left(m\right))/336---\left(8\right)$

Wherein, described SSS_Threshold is the decision threshold of default SSS power detection;

Need to prove that above-mentioned PSS_Threshold and SSS_Threshold can test empirical data by reality and measure, and are not limited to a certain numerical value, and above-mentioned judgement form is not unique judgement form yet.

S605: judge whether PBCH can be demodulated:

According to the residential quarter ID that obtains and frame timing demodulation PBCH, if the demodulation success, execution in step S606, otherwise reject this alias point, and return S603;

If the demodulation failure, then this frequency is the alias point, and this frequency is removed from candidate's frequency point sets, if the demodulation success obtains system bandwidth information, then this frequency is true frequency

From S603-S605 as can be known, in candidate's frequency point sets, have frequency not meet arbitrary condition, all disallowable, thereby greatly reduced scanning consume total time, and improve the accuracy of final scanning element.

S606: judge whether the frequency band occupancy does not repeat;

Whether the candidate's frequency that extracts one by one in described candidate's frequency point sets overlaps with as a result frequency comparison of described frequency point scanning frequency band, and respective frequencies and bandwidth are respectively: f _mAnd f _n, bandwidth is respectively BW _mAnd BW _n, when

$|f_m-f_n|\&le;\frac{B{W}_m+{\mathrm{<figure-callout\; id="2"\; label="BW\; n"\; filenames="HDA00002273352100011.png,HDA00002273352100012.png"\; state="\{\{state\}\}">BW</figure-callout>}}_n}{2}$ The time, remove this candidate's frequency.

Wherein true frequency participates in calculating by the bandwidth out of demodulation from PBCH, and the time bandwidth of candidate's frequency is pressed minimum bandwidth 1.4M and calculated.The principle that this step is followed is that the frequency band that any two frequencies take in the LTE system can not repeat.

S607: obtain scanning result.

Fig. 7 shows a kind of frequency point scanning processor towards LTE, comprising:

Frequency band subcarrier average power is calculated module 701, is used for obtaining interior each sub-carrier power of frequency band and the calculating frequency band subcarrier average power take Resource Block as unit;

Candidate's frequency determination module 702, be used for according to default step-length, determine candidate's frequency point sets in candidate's frequency zone, described candidate's frequency district inclusion has the Resource Block that satisfies a default said conditions, and the frequency band subcarrier average power of described Resource Block is greater than decision threshold;

Frequency is rejected module 703, be used for rejecting the frequency that described candidate's frequency point sets does not meet main synchronizing symbol PSS and auxiliary synchronizing symbol SSS power detection condition, and the alias point by demodulation physical layer broadcast channel PBCH demodulation failure, obtain the frequency point scanning result.

Fig. 8 shows another module of calculating module towards the frequency point scanning processor midband subcarrier average power of LTE and forms, and comprising:

Frequency domain modular converter 801 receives time-domain signal according to default center frequency point, and forwards described time-domain signal to frequency domain;

Cumulative power computation module 802 is used for the power of each subcarrier in frequency domain calculates frequency band, and within the default cumulative time power of each subcarrier is added up, and obtains cumulative power;

Average power is calculated module 803, is used for take Resource Block as unit described cumulative power calculation average power.

Fig. 9 shows another candidate's frequency determination module in the frequency point scanning processor of LTE and comprises:

Candidate's frequency zone determination module 901, be used for judging whether current frequency zone includes at least 6 continuous resource pieces, and the frequency band subcarrier average power of described Resource Block is more than or equal to default decision threshold, and if so, then current frequency zone is candidate's frequency zone;

Order module 902 is used for take 100KHz as step-length, and each 3 average power that resource is fast about calculating in described candidate's frequency zone by arranging from big to small, obtain candidate's frequency point sets $[f_1^C,f_2^C,f_3^C,...,f_N^C].$

Figure 10 shows another towards the frequency point scanning processor of LTE, on the basis of the diagram of Fig. 7 and explanation thereof, also comprises:

Main synchronizing symbol PSS detection module 1001, it is relevant to be used for utilizing the local sequence of described PSS and the time-domain signal of reception to do time domain with preset interval time to each candidate's frequency of candidate's frequency point sets, obtains a plurality of related powers;

Search maximal correlation power P SS_Max_Power in a plurality of related powers, and calculate average related power PSS_Ave_Power in a plurality of related powers, when

$\frac{\mathrm{PSS}\_\mathrm{Max}\_\mathrm{Power}}{\mathrm{PSS}\_\mathrm{Ave}\_\mathrm{Power}}<\mathrm{PSS}\_\mathrm{Threshold}$ The time, candidate's frequency that then this related power is corresponding is disallowable;

Wherein, PSS_Threshold is the decision threshold of default PSS power detection.

Auxiliary synchronous signals SSS detection module 1002 is used for extracting subcarrier corresponding to described SSS at frequency domain, described subcarrier and SSS this locality sequence is done relevant, obtains a plurality of related powers;

Search maximal correlation power SSS_Max_Power in a plurality of related powers, and calculate average related power SSS_Ave_Power, when

$\frac{\mathrm{SSS}\_\mathrm{Max}\_\mathrm{Power}}{\mathrm{SSS}\_\mathrm{Ave}\_\mathrm{Power}}<\mathrm{SSS}\_\mathrm{Threshold}$ The time, candidate's frequency that then this related power is corresponding is disallowable;

Described SSS_Threshold is the decision threshold of default SSS power detection.

Candidate's frequency demodulation determination module 1003 is used for:

According to the residential quarter ID that obtains and frame timing demodulation PBCH, if the demodulation failure, candidate's frequency that then this related power is corresponding is disallowable.

Whether can not reject module 1004 by frequency, overlap with as a result frequency comparison of described frequency point scanning frequency band for the candidate's frequency that extracts one by one described candidate's frequency point sets, respective frequencies and bandwidth are respectively: f _mAnd f _n, bandwidth is respectively BW _mAnd BW _n, when

$|f_m-f_n|\&le;\frac{B{W}_m+{\mathrm{<figure-callout\; id="2"\; label="BW\; n"\; filenames="HDA00002273352100011.png,HDA00002273352100012.png"\; state="\{\{state\}\}">BW</figure-callout>}}_n}{2}$ The time, remove this candidate's frequency.

Need to prove that described main synchronizing symbol PSS detection module, auxiliary synchronous signals SSS detection module and candidate's frequency demodulation determination module can embed frequency and reject in the module, also can arrange separately.

Above-mentioned module is interpreted as the predefined process of described processor, and described processor is carried out the modules function and exported the frequency point scanning result.

Figure 11 shows a kind of frequency point scanning device towards LTE, comprising: scanning processor 1101, and memory 1102, described frequency point scanning processor 1101 is connected with memory 1102 by interface.

Described memory 1102 stores frequency band subcarrier average power calculating instruction, candidate's frequency determines that instruction and frequency propose instruction, and described frequency point scanning processor 1101 calls and carry out above-mentioned instruction, wherein:

Described frequency band subcarrier average power is calculated instruction, is used for obtaining interior each sub-carrier power of frequency band and the calculating frequency band subcarrier average power take Resource Block as unit;

Described candidate's frequency is determined instruction, be used for according to default step-length, determine candidate's frequency point sets in candidate's frequency zone, described candidate's frequency district inclusion has the Resource Block that satisfies a default said conditions, and the frequency band subcarrier average power of described Resource Block is greater than decision threshold;

Described frequency proposes instruction, be used for rejecting the frequency that described candidate's frequency point sets does not meet main synchronizing symbol PSS and auxiliary synchronizing symbol SSS power detection condition, and the alias point by demodulation physical layer broadcast channel PBCH demodulation failure, obtain the frequency point scanning result.

The described frequency band subcarrier average power calculating instruction of storage comprises in the described memory 1102:

Frequency domain conversion instruction piece is used for receiving time-domain signal according to default center frequency point, and forwards described time-domain signal to frequency domain;

Cumulative power calculation instruction block is used for the power of each subcarrier in frequency domain calculates frequency band, and within the default cumulative time power of each subcarrier is added up, and obtains cumulative power;

Average power is calculated instruction block, is used for take Resource Block as unit described cumulative power calculation average power.

Candidate's frequency of storage determines that instruction comprises in the described memory 1102:

Instruction is determined in candidate's frequency zone, is used for judging whether current frequency zone includes at least 6 continuous resource pieces, and the frequency band subcarrier average power of described Resource Block is more than or equal to default decision threshold, and if so, then current frequency zone is that candidate's frequency is regional;

The ordering instruction is used for take 100KHz as step-length, and each 3 average power that resource is fast about calculating in described candidate's frequency zone by arranging from big to small, obtain candidate's frequency point sets

And, also store in the described memory 1102:

Synchronizing symbol PSS detects instruction, and it is relevant to be used for utilizing the local sequence of described PSS and the time-domain signal of reception to do time domain with preset interval time to each candidate's frequency of candidate's frequency point sets, obtains a plurality of related powers;

Search maximal correlation power P SS_Max_Power in a plurality of related powers, and calculate average related power PSS_Ave_Power in a plurality of related powers, when

$\frac{\mathrm{PSS}\_\mathrm{Max}\_\mathrm{Power}}{\mathrm{PSS}\_\mathrm{Ave}\_\mathrm{Power}}<\mathrm{PSS}\_\mathrm{Threshold}$ The time, candidate's frequency that then this related power is corresponding is disallowable;

Wherein, PSS_Threshold is the decision threshold of default PSS power detection.

Auxiliary synchronous signals SSS detects instruction, is used for extracting subcarrier corresponding to described SSS at frequency domain, described subcarrier and SSS this locality sequence is done relevant, obtains a plurality of related powers;

Search maximal correlation power SSS_Max_Power in a plurality of related powers, and calculate average related power SSS_Ave_Power, when

$\frac{\mathrm{SSS}\_\mathrm{Max}\_\mathrm{Power}}{\mathrm{SSS}\_\mathrm{Ave}\_\mathrm{Power}}<\mathrm{SSS}\_\mathrm{Threshold}$ The time, candidate's frequency that then this related power is corresponding is disallowable;

Described SSS_Threshold is the decision threshold of default SSS power detection.

Candidate's frequency demodulation decision instruction is used for:

According to the residential quarter ID that obtains and frame timing demodulation PBCH, if the demodulation failure, candidate's frequency that then this related power is corresponding is disallowable.

Whether can not reject instruction by frequency, overlap with as a result frequency comparison of described frequency point scanning frequency band for the candidate's frequency that extracts one by one described candidate's frequency point sets, respective frequencies and bandwidth are respectively: f _mAnd f _n, bandwidth is respectively BW _mAnd BW _n, when

$|f_m-f_n|\&le;\frac{B{W}_m+{\mathrm{<figure-callout\; id="2"\; label="BW\; n"\; filenames="HDA00002273352100011.png,HDA00002273352100012.png"\; state="\{\{state\}\}">BW</figure-callout>}}_n}{2}$ The time, remove this candidate's frequency.

Described frequency point scanning device towards LTE can be interpreted as the forms such as integrated chip and be embedded in the data user of the institute terminal, and described user terminal can be the equipment such as mobile phone, laptop computer, panel computer;

Also can be interpreted as user terminal itself.

Need to prove, device embodiment described above only is schematic, wherein said unit as the separating component explanation can or can not be physically to separate also, namely can be positioned at a place, perhaps also can be distributed on a plurality of network element.Can select according to the actual needs wherein some or all of hardware to realize the purpose of present embodiment scheme.Those of ordinary skills namely can understand and implement in the situation of not paying creative work.

Figure 12 shows a kind of frequency point scanning system towards LTE, comprise that Figure 11 illustrates and the frequency point scanning device 1201 towards LTE of corresponding explanation, scanning means shown in the figure receives in the band limits for it and carries out effective Serving cell working frequency points, the structure of described frequency point scanning device and principle, can be referring to Figure 11 diagram and corresponding explanation thereof, the scanning means 1201 shown in Figure 12 can integrated chip etc. form be embedded in the data user of the institute terminal, described user terminal can be the equipment such as mobile phone, laptop computer, panel computer.

Certainly, also can make the scanning means shown in Figure 13, this device can pass through a move media to be realized, and is used with equipment such as mobile phone, laptop computer, panel computers, and referring to Figure 14, more ways of realization repeat no more.

In sum:

The method for scanning frequency points towards LTE in the embodiment of the invention averages power calculation take Resource Block as unit, and will meet pre-conditioned Resource Block composition candidate frequency zone, possible sweep limits is drawn a circle to approve in candidate's frequency zone, thereby overcome the shortcoming that prior art scans one by one to the frequency in the broadband, in to described candidate's frequency zone, do not meet for main synchronizing symbol PSS and auxiliary synchronizing symbol SSS power detection condition, and frequency that can not demodulation physical layer broadcast channel PBCH is rejected, thereby in qualified candidate's frequency zone, obtain the frequency point scanning result, and the channel of getting rid of other dynamic assignment impact that power detection is caused, improved the accuracy of candidate's frequency, and calculate average power take described Resource Block as unit, owing to include reference symbol in the Resource Block, guaranteed the validity that candidate's frequency point sets is chosen.

Each embodiment adopts the mode of going forward one by one to describe in this specification, and what each embodiment stressed is and the difference of other embodiment that identical similar part is mutually referring to getting final product between each embodiment.For the disclosed processor of embodiment, device and system, because it is corresponding with the disclosed method of embodiment, so description is fairly simple, relevant part partly illustrates referring to method and gets final product.

It will be understood by those skilled in the art that and to represent information, message and signal with many different techniques and in the technology any one.For example, the message of mentioning in the above-mentioned explanation, information can be expressed as voltage, electric current, electromagnetic wave, magnetic field or magnetic particle, light field or above combination in any.

The method of describing in conjunction with embodiment disclosed herein or the step of algorithm can directly use the software module of hardware, processor execution, and perhaps the combination of the two is implemented.Software module can place the storage medium of any other form known in random asccess memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable ROM, register, hard disk, moveable magnetic disc, CD-ROM or the technical field.

One of ordinary skill in the art will appreciate that all or part of flow process that realizes in above-described embodiment method, to come the relevant hardware of instruction to finish by computer program, described program can be stored in the computer read/write memory medium, this program can comprise the flow process such as the embodiment of above-mentioned each side method when carrying out.Wherein, described storage medium can be magnetic disc, CD, read-only store-memory body (Read-Only Memory, ROM) or store-memory body (Random Access Memory, RAM) etc. at random.

To the above-mentioned explanation of the disclosed embodiments, make this area professional and technical personnel can realize or use the present invention.Multiple modification to these embodiment will be apparent concerning those skilled in the art, and General Principle as defined herein can in the situation of the spirit or scope that do not break away from the embodiment of the invention, realize in other embodiments.Therefore, the embodiment of the invention will can not be restricted to these embodiment shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.

Claims (16)

1. the method for scanning frequency points of a LTE is characterized in that, comprising:

Obtain interior each sub-carrier power of frequency band and the calculating frequency band subcarrier average power take Resource Block as unit;

According to default step-length, in candidate's frequency zone, determine candidate's frequency point sets, described candidate's frequency district inclusion has the Resource Block that satisfies a default said conditions, and the frequency band subcarrier average power of described Resource Block is greater than decision threshold;

Reject the frequency that does not meet main synchronizing symbol PSS and auxiliary synchronizing symbol SSS power detection condition in described candidate's frequency point sets, and the alias point by demodulation physical layer broadcast channel PBCH demodulation failure, the frequency point scanning result obtained.

2. method for scanning frequency points as claimed in claim 1 is characterized in that, obtains interior each sub-carrier power of frequency band and calculate frequency band subcarrier average power take Resource Block as unit to comprise:

Receive time-domain signal according to default center frequency point, and forward described time-domain signal to frequency domain;

The power of each subcarrier in frequency domain calculates frequency band, and within the default cumulative time, the power of each subcarrier is added up, cumulative power obtained;

Take Resource Block as unit to described cumulative power calculation average power.

3. method for scanning frequency points as claimed in claim 1 is characterized in that, according to default step-length, determines that in candidate's frequency zone candidate's frequency point sets comprises:

Judge whether current frequency zone includes at least 6 continuous resource pieces, and the frequency band subcarrier average power of described Resource Block is more than or equal to default decision threshold, if so, then current frequency zone is candidate's frequency zone;

Take 100KHz as step-length, each 3 average power that resource is fast about calculating in described candidate's frequency zone by arranging from big to small, obtain candidate's frequency point sets

4. method for scanning frequency points as claimed in claim 2 is characterized in that, also comprises detecting main synchronizing symbol PSS, comprising:

It is relevant to utilize the local sequence of described PSS and the time-domain signal of reception to do time domain with preset interval time to each candidate's frequency in candidate's frequency point sets, obtains a plurality of related powers;

Search maximal correlation power P SS_Max_Power in a plurality of related powers, and calculate average related power PSS-Ave-Power in a plurality of related powers, when

The time, candidate's frequency that then this related power is corresponding is disallowable;

Wherein, PSS_Threshold is the decision threshold of default PSS power detection.

5. method for scanning frequency points as claimed in claim 2 is characterized in that, also comprises detecting auxiliary synchronous signals SSS, comprising:

Extract subcarrier corresponding to described SSS at frequency domain, described subcarrier and SSS this locality sequence are done relevant, obtain a plurality of related powers;

Search maximal correlation power SSS_Max_Power in a plurality of related powers, and calculate average related power SSS_Ave_Power, when

The time, candidate's frequency that then this related power is corresponding is disallowable;

Described SSS_Threshold is the decision threshold of default SSS power detection.

6. method for scanning frequency points as claimed in claim 1 is characterized in that, also comprises demodulation judgement candidate frequency, comprising:

According to the residential quarter ID that obtains and frame demodulation PBCH regularly, if the demodulation failure, candidate's frequency that then this related power is corresponding is disallowable, otherwise judges that this frequency is frequency point scanning frequency as a result.

7. method for scanning frequency points as claimed in claim 6 is characterized in that, comprises that also the frequency band occupancy does not repeat to judge:

Whether the candidate's frequency that extracts one by one in described candidate's frequency point sets overlaps with as a result frequency comparison of described frequency point scanning frequency band, and respective frequencies and bandwidth are respectively: f _mAnd f _n, bandwidth is respectively BW _mAnd BW _n, when

The time, remove this candidate's frequency.

8. the frequency point scanning processor towards LTE is characterized in that, comprising:

Frequency band subcarrier average power is calculated module, is used for obtaining interior each sub-carrier power of frequency band and the calculating frequency band subcarrier average power take Resource Block as unit;

Candidate's frequency determination module is used for according to default step-length, determines candidate's frequency point sets in candidate's frequency zone, and described candidate's frequency district inclusion has the Resource Block that satisfies a default said conditions, and the frequency band subcarrier average power of described Resource Block is greater than decision threshold;

Frequency is rejected module, is used for rejecting the frequency that described candidate's frequency point sets does not meet main synchronizing symbol PSS and auxiliary synchronizing symbol SSS power detection condition, and the alias point by demodulation physical layer broadcast channel PBCH demodulation failure, obtains the frequency point scanning result.

9. frequency point scanning processor as claimed in claim 8 is characterized in that, described frequency band subcarrier average power is calculated module and comprised:

The frequency domain modular converter is used for receiving time-domain signal according to default center frequency point, and forwards described time-domain signal to frequency domain;

Cumulative power computation module is used for the power of each subcarrier in frequency domain calculates frequency band, and within the default cumulative time power of each subcarrier is added up, and obtains cumulative power;

Average power is calculated module, is used for take Resource Block as unit described cumulative power calculation average power.

10. frequency point scanning processor as claimed in claim 8 is characterized in that, described candidate's frequency determination module comprises:

Candidate's frequency zone determination module is used for judging whether current frequency zone includes at least 6 continuous resource pieces, and the frequency band subcarrier average power of described Resource Block is more than or equal to default decision threshold, and if so, then current frequency zone is that candidate's frequency is regional;

Order module is used for take 100KHz as step-length, and each 3 average power that resource is fast about calculating in described candidate's frequency zone by arranging from big to small, obtain candidate's frequency point sets

11. frequency point scanning processor as claimed in claim 8, it is characterized in that, also comprise: main synchronizing symbol PSS detection module, it is relevant to be used for utilizing the local sequence of described PSS and the time-domain signal of reception to do time domain with preset interval time to each candidate's frequency of candidate's frequency point sets, obtains a plurality of related powers;

Search maximal correlation power P SS_Max_Power in a plurality of related powers, and calculate average related power PSS_Ave_Power in a plurality of related powers, when

The time, candidate's frequency that then this related power is corresponding is disallowable;

Wherein, PSS_Threshold is the decision threshold of default PSS power detection.

12. frequency point scanning processor as claimed in claim 8, it is characterized in that, also comprise: auxiliary synchronous signals SSS detection module is used for extracting subcarrier corresponding to described SSS at frequency domain, the local sequence of described subcarrier and SSS is done relevant, obtained a plurality of related powers;

Search maximal correlation power SSS_Max_Power in a plurality of related powers, and calculate average related power SSS_Ave_Power, when

The time, candidate's frequency that then this related power is corresponding is disallowable;

Described SSS_Threshold is the decision threshold of default SSS power detection.

13. frequency point scanning processor as claimed in claim 8 is characterized in that, also comprises: candidate's frequency demodulation determination module is used for:

According to the residential quarter ID that obtains and frame timing demodulation PBCH, if the demodulation failure, candidate's frequency that then this related power is corresponding is disallowable.

14. frequency point scanning processor as claimed in claim 13, it is characterized in that, whether also comprise: can not reject module by frequency, overlap with as a result frequency comparison of described frequency point scanning frequency band for the candidate's frequency that extracts one by one described candidate's frequency point sets, respective frequencies and bandwidth are respectively: f _mAnd f _n, bandwidth is respectively BW _mAnd BW _n, when

The time, remove this candidate's frequency.

15. the frequency point scanning device towards LTE is characterized in that, comprises the frequency point scanning processor towards LTE in each claim of claim 8-14, and memory, described scanning processor is connected with memory by interface.

16. the frequency point scanning system towards LTE is characterized in that, comprising: the frequency point scanning device towards LTE in the claim 15.

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