CN102158943A - Mobile terminal and method for controlling gain in mobile terminal - Google Patents

Abstract

The invention discloses a mobile terminal and a method for controlling the gain in the mobile terminal. The mobile terminal comprises a related device, a measuring device, a control device and a gain adjusting device, wherein the related device responds to the instruction of the control device, obtains sample sequences corresponding to a field and a subsequent symbol from a scheduled time slicing duplex channel of a base station, and uses at least one master synchronization sequence to be related to all subsequences in the sample sequences to obtain all related results; the measuring device responds to the obtained related results, and computes a peak to average ratio of a related result which is obtained by using a largest related result and corresponds to the master synchronization sequence aiming at the large related result in the related results; the control device responds to the fixing of the existence of the base station and sends the instruction to the related device, and informs the gain adjusting device when the peak to average ratio is at least smaller than a first threshold value; the gain adjusting device responds to the gain of a variable gain amplifier, which is informed to be increased; and the related device also normalizes the related results according to the power of samples of all the subsequences corresponding to all the related results.

Description

The method of ride gain in portable terminal and the portable terminal

Technical field

The present invention relates to third generation partner plan (3GPP) Long Term Evolution (LTE) time division duplex (TDD) technology, relate in particular to method based on ride gain in the portable terminal of 3GPP LTE TDD technology and the such portable terminal.

Background technology

Along with developing rapidly of mobile communication technology, wireless communication system presents the trend of mobile, broadband and IPization, and the competition in mobile communication market also is growing more intense.For tackling from WiMAX, the challenge of tradition such as Wi-Fi and emerging WiMAX access technology, improve the competitiveness of 3-G (Generation Three mobile communication system) (3G) in broadband wireless access market, 3GPP carries out universal mobile telecommunications system (UMTS) terrestrial wireless and inserts (UTRA) Long Term Evolution (LTE) Study on Technology, to realize 3G technology seamlessly transitting to super 3 g mobile communication system (B3G) and the 4th 4G of third-generation mobile communication system.The improvement target of LTE is to realize higher data rate, shorter time delay, lower cost, higher power system capacity and improved coverage.

The LTE system has defined Frequency Division Duplexing (FDD) (FDD) and time division duplex (TDD) dual mode simultaneously.Two kinds of frame structures of LTE TDD have been unified in 3GPP RAN1 meeting.The fusion of tdd frame structure makes LTE TDD technology be subjected to paying attention to widely.

Portable terminal in the LTE system (or claims subscriber unit, UE) starts shooting or when entering new sub-district, need set up with the base station and get in touch.The work of the first step is the signal of search base station on predetermined channel.If search signal of base station, promptly determine to exist the base station, then attempt setting up synchronously.The base station of LTE system comprises two kinds of synchronizing signals in signal, i.e. master sync signal (PSS) and auxiliary synchronous signals (SSS), and they determine the sign of sub-district jointly.Portable terminal is at first set up synchronously according to PSS in synchronizing process, to determine the 5ms border, sets up synchronously according to SSS then, to determine the 10ms border.

In synchronizing process, portable terminal need carry out automatic gain control (AGC) to adapt to the signal power fluctuation of proper range.Usually, AGC needs the measurement data received power, calculates average power and carries out gain controlling according to the difference of average power and reference value.

People constantly work hard and improve AGC, to improve synchronous accuracy.

Summary of the invention

Between the sync period of initial access phase, because portable terminal is not set up synchronously, the initial of training signal do not have clearly, and the existence of signal can not be determined.Under these circumstances, conventional method is measured the data power in the predetermined interval and is carried out gain controlling.

In LTE TDD system, may comprise downstream signal and upward signal between measurement zone.Fig. 1 shows the scene that may occur that.Consider scene shown in Figure 1, portable terminal 101 enters the scope of the sub-district of base station 103, thereby is in initial access phase and sets up operation synchronously.Contiguous portable terminal 102 communicates with base station 103.Because the power of upward signal is usually far above the power of downstream signal, the upward signal of portable terminal 102 can bring considerable influence to the power measurement in the portable terminal 101, make conventional method can not determine the accurate power level of downstream signal, cause appropriate gain can't be set, thereby influence synchronous foundation.

In addition, depend on residing communication environment, may there be higher Gaussian noise in the signal that portable terminal receives.Conventional method is to improve the influence that gain overcomes Gaussian noise.Can require variable gain amplifier that higher dynamic range is arranged like this, cause the raising of cost and power consumption.

The purpose of this invention is to provide the method for ride gain in a kind of portable terminal and the such portable terminal, it allows to alleviate at least in part or overcome above-mentioned defective.

In one embodiment of the invention, portable terminal is applicable to the system that plans the Long Term Evolution project based on third generation partner, and comprises relevant apparatus, measurement mechanism, control device and gain adjustment device.Relevant apparatus can be in response to the indication from control device, obtain sample sequence from the predetermined time division duplex channel of base station corresponding to a field and a follow-up symbol, and relevant to obtain each correlated results with at least one main synchronizing sequence with all subsequences in the described sample sequence.Measurement mechanism can at the largest correlation result in the described correlated results, calculate the peak-to-average force ratio of the correlated results of the corresponding main synchronizing sequence acquisition of using described largest correlation result in response to the correlated results that is obtained.Control device can send described indication to described relevant apparatus in response to the existence of determining the base station, and at least under the situation of described peak-to-average force ratio less than first threshold, the notice gain adjustment device.Gain adjustment device can improve the gain of variable gain amplifier in response to described notice.Relevant apparatus can also be according to the power of the sample of the corresponding subsequence of each described correlated results with described correlated results normalization.

In above-mentioned portable terminal, control device also can surpass under the situation of second threshold value less than first threshold and based on the number of times that current gain relevant apparatus obtains sample sequence at described peak-to-average force ratio, notifies described gain adjustment device.Control device can not surpass under the situation of second threshold value less than first threshold and described number of times at described peak-to-average force ratio yet, sends described indication to relevant apparatus.Relevant apparatus also can not change and obtains from the predetermined time division duplex channel of described base station once more under the situation corresponding to the sample sequence of a field and a follow-up symbol in gain, the correlated results that obtains based on relevant between the subsequence of the same position in identical main synchronizing sequence and each sample sequence under the current gain and or its average, as the correlated results that is obtained.

In above-mentioned portable terminal, peak-to-average force ratio can be described largest correlation result with described correlated results in and described largest correlation result adopt the ratio of the average of other correlated results that identical main synchronizing sequence obtains, maybe can be described largest correlation result and the ratio of the average of all correlated results that adopt identical main synchronizing sequence acquisition.

In above-mentioned portable terminal, gain adjustment device also can be lower than under the situation of the 3rd threshold value in next gain that is higher than current gain, and described next gain is brought up in the gain of variable gain amplifier.

In one embodiment of the invention, for being applicable to the portable terminal of planning the system of Long Term Evolution project based on third generation partner, wherein the method for ride gain can comprise correlation step, measuring process, controlled step and gain-adjusted step.Can be in correlation step in response to relevant indication, obtain sample sequence from the predetermined time division duplex channel of base station corresponding to a field and a follow-up symbol, and relevant to obtain each correlated results with at least one main synchronizing sequence with all subsequences in the described sample sequence.Can at the largest correlation result in the described correlated results, calculate the peak-to-average force ratio of the correlated results of the corresponding main synchronizing sequence acquisition of using described largest correlation result in response to the correlated results that is obtained at measuring process.Can provide described relevant indication in response to the existence of determining the base station in controlled step, and at least under the situation of described peak-to-average force ratio, provide and improve the gain notice less than first threshold.The gain-adjusted step can be in response to the gain of described raising gain notice raising variable gain amplifier.Correlation step comprises according to the power of the sample of the corresponding subsequence of each described correlated results with described correlated results normalization.

In said method, controlled step also can be included in described ratio and surpass under the situation of second threshold value less than first threshold and based on the number of times that current gain obtains sample sequence, and described raising gain notice is provided.Controlled step also can be included in described ratio and not surpass under the situation of second threshold value less than first threshold and described number of times, and described relevant indication is provided.Under correlation step can be included in also that gain does not change and obtain situation corresponding to the sample sequence of a field and a follow-up symbol from the predetermined time division duplex channel of described base station once more, the correlated results that obtains based on relevant between the subsequence of the same position in identical main synchronizing sequence and each sample sequence under the current gain and or its average, as the correlated results that is obtained.

In said method, described peak-to-average force ratio can be described largest correlation result with described correlated results in and described largest correlation result adopt the ratio of the average of other correlated results that identical main synchronizing sequence obtains, maybe can be described largest correlation result and the ratio of the average of all correlated results that adopt identical main synchronizing sequence acquisition.

In said method, the gain-adjusted step also can be included in next gain that is higher than current gain and be lower than under the situation of the 3rd threshold value, and described next gain is brought up in the gain of variable gain amplifier.

Description of drawings

With reference to below in conjunction with the explanation of accompanying drawing, can understand above and other purpose of the present invention, characteristics and advantage more easily to the embodiment of the invention.In the accompanying drawings, technical characterictic or parts identical or correspondence will adopt identical or corresponding Reference numeral to represent.

The scene that comprises downstream signal and upward signal in Fig. 1 shows and may cause between measurement zone.

Fig. 2 shows the frame structure of LTE TDD system.

Fig. 3 shows the position of PSS signal in the frame of LTE TDD system.

Fig. 4 is the block diagram that illustrates according to the portable terminal of the embodiment of the invention.

Fig. 5 is the flow chart that illustrates according to the method for the ride gain of the embodiment of the invention.

Fig. 6 is the flow chart of improving one's methods that illustrates according to the method for ride gain in the portable terminal of the embodiment of the invention.

Fig. 7 is the schematic diagram that the effect that reaches by normalization is shown.

Embodiment

Embodiments of the invention are described with reference to the accompanying drawings.Should be noted that for purpose clearly, omitted the parts that have nothing to do with the present invention, those of ordinary skills are known and the expression and the description of processing in accompanying drawing and the explanation.

The structure of the frame structure and the PSS signal of LTE TDD system at first is described, is beneficial to understand embodiments of the invention.

Fig. 2 shows the frame structure of LTE TDD system.Fig. 3 shows the position of PSS signal in the frame of LTETDD system.

As shown in Figure 2, LTE TDD system organizes data with the form of frame, and the frame of 10ms is divided into 10 subframes.Each subframe comprises two time slots.The long 0.5ms of each time slot and form by some OFDMs (OFDM) symbol.For different band width configuration, the interval difference of each sampled point, but be the integral multiple (Ts=1/ (15000 * 2048) s) of Ts.Fig. 2 shows the band width configuration of 20MHz.

As shown in Figure 2, each 10ms frame comprises that 2 length are the field of 5ms.Each field is made up of 4 data subframes (#0, #2, #3 and #4, or #5, #7, #8 and #9) and 1 special subframe (#1 or #6).Special subframe comprises 3 special time slot: DwPTS, and GP and UpPTS, total length are 1ms.The length of DwPTS and UpPTS is configurable.The length of DwPTS is 3～12 OFDM symbols.The length of UpPTS is 1～2 OFDM symbol.Correspondingly, GP length is 1～10 OFDM symbol.

The cycle of LTE TDD synchronizing signal is 5ms, is divided into master sync signal (PSS) and auxiliary synchronous signals (SSS).PSS signal one has 3, from frequency domain, is expressed as the different Zadoff-Chu sequence of parameter, with reference to following formula

$d_u\left(n\right)=\left\{\begin{array}{cc}{e}^{-j\frac{\mathrm{\πun}(n+1)}{63}}& n=\mathrm{0,1},...,30\\ e^{-j\frac{\mathrm{\πu}(n+1)(n+2)}{63}}& n=\mathrm{31,32},...,61\end{array}\right.$

Wherein parameters u desirable 25,29,34.

This sequence (length is 62) can be mapped near 62 subcarriers of centered carrier on the frequency domain (DC), and respectively mends 5 zero in both sides, takies 72 subcarriers altogether.Through inverse Fourier transform (IFFT), the OFDM symbol that comprises PSS can be put on the 3rd the OFDM symbol of subframe #1, subframe #6 in the LTE tdd frame.Because the duration of subframe is 1ms, so the transmission cycle of PSS is 5ms.As shown in Figure 3.In LTE tdd frame structure, PSS is positioned at the 3rd symbol of DwPTS, and SSS is positioned at last symbol of first subframe of 5ms.The further details of relevant LTE tdd frame structure can be with reference to 3GPP standard: TS36.211v8.7.0.

Fig. 4 is the block diagram that illustrates according to the portable terminal 400 of the embodiment of the invention, and wherein portable terminal 400 is applicable to the system based on 3GPP LTE.

As shown in Figure 4, portable terminal 400 comprises relevant apparatus 405, measurement mechanism 406, control device 407 and gain adjustment device 408.The simple purpose of understanding embodiments of the invention for convenience also shows antenna 401, variable gain amplifier (VGA) 402, analog to digital converter (A/D) 403 and low pass filter (LPF) 404 among Fig. 4, do not constitute the restriction to embodiments of the invention.

When portable terminal 400 is started shooting or entered the coverage of another base station, need to insert the base station of this coverage in the coverage of a base station.Because portable terminal 400 has not known whether the base station at this moment, at first attempt receiving from signal of base station to determine whether the base station exists at predetermined channel at initial access phase.In this process, by antenna 401 received signals.VGA 402 amplifies the signal that receives with predetermined gain (being generally less or minimum gain).A/D 403 is sampled as digital signal with amplifying signal.404 pairs of digital signals of LPF are carried out low-pass filtering.Unshowned judgment means determines whether to exist the base station according to the power of filtering signal.If exist, then start synchronizing process.

Control device 407 sends indication in response to the existence of determining the base station to relevant apparatus 405.

Relevant apparatus 405 is in response to the indication from control device 407, obtains sample sequence corresponding to a field and a follow-up symbol from the predetermined time division duplex channel of base station.With the 20MHz band width configuration is example, and field length is 153600 Ts, reduces 16 times through sampling, corresponding to 9600 samples.A symbol is corresponding to 128 samples.Can obtain the sample sequence of 9728 samples.

At least one PSS signal of relevant apparatus 405 usefulness (promptly main synchronizing sequence) is relevant to obtain each correlated results with all subsequences in the sample sequence.Allow three kinds of main synchronizing sequences in the LTE TDD standard.Can use wherein a kind of, two or three main synchronizing sequence according to the agreement of concrete system.According to relevant purpose as can be known, the length of subsequence is identical with the length of main synchronizing sequence.Adjacent subsequence in all subsequences of sample sequence is offset a sample each other.Thereby all subsequences cover whole sample sequence.

With the 20MHz band width configuration is example, PSS (i), i=0, three kinds of main synchronizing sequences of 1,2 expression.PSS (i, k), k=0,1,2 ..., thresholding during 128 of 127 expression i main synchronizing sequences.R represents sample sequence.R (j), j=0,1,2 ..., 9728 samples of 9727 expression sample sequences.

C (i, m) in expression i main synchronizing sequence and the sample sequence from the correlated results of the initial subsequence rs (m) of m sample, wherein

$C(i,m)={|\underset{k=0}{\overset{127}{\mathrm{\Σ}}}r{(k+m)}^{*}\·\mathrm{PSS}(i,k)|}^2---\left(1.1\right)$

Wherein * represents conjugation, m=0, and 1,2 ..., 9599.Should be appreciated that and to utilize other related operation to obtain correlated results.

In this example, for a sample sequence, obtain 9600 correlated results.

(i, m), (i, (i, m) normalization obtain the normalization correlated results to relevant apparatus 405 with correlated results C for the power of the sample of corresponding subsequence rs (m) m) and N (m) according to correlated results C for each C

, wherein

$N\left(m\right)=\underset{k=0}{\overset{127}{\mathrm{\Σ}}}{\left|r(k+m)\right|}^2---\left(2.1\right)$

$\tilde{C}(i,m)=\frac{C(i,m)}{N\left(m\right)}---\left(3.1\right)$

Should be appreciated that and to adopt different power and definition.

Measurement mechanism 406 is in response to these correlated results that obtained

, determine the largest correlation result in these correlated results

$\tilde{C}(i_0,m_0)=\underset{i,m}{\max }\left\{\tilde{C}(i,m)\right\}---\left(4\right)$

At largest correlation result

, calculate and use largest correlation result

Corresponding main synchronizing sequence PSS (i ₀) correlated results that obtains

, m=0,1,2 ..., 9599 peak-to-average force ratio M.

For example, peak-to-average force ratio M can be largest correlation result with correlated results in and largest correlation result adopt the ratio of the average of other correlated results that identical main synchronizing sequence obtains.Particularly,

$M=\frac{\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)}{\frac{1}{9600-1}\underset{m=0,m\&NotEqual;{\mathrm{<figure-callout\; id="0"\; label="m"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">m</figure-callout>}}_0}{\overset{9599}{\mathrm{\&Sigma;}}}\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m)}---\left(5.1\right)$

For example, peak-to-average force ratio M can be a largest correlation result and the ratio of the average of all correlated results that adopt identical main synchronizing sequence to obtain.Particularly,

$M=\frac{\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)}{\frac{1}{9600}\underset{m=0}{\overset{9599}{\mathrm{\&Sigma;}}}\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m)}---\left(5.2\right)$

Should be appreciated that peak-to-average force ratio M can define according to other calculates.

Control device 407 is (this shows that current gain is not suitable for setting up synchronous needs) under the situation of peak-to-average force ratio M less than first threshold, notice gain adjustment device 408.

Gain adjustment device 408 improves the gain of variable gain amplifier in response to the notice of control device 407.

Fig. 5 is the flow chart that illustrates according to the method for ride gain in the portable terminal of the embodiment of the invention, and this portable terminal is applicable to the system based on 3GPP LTE.

When portable terminal is started shooting or entered the coverage of another base station, need to insert the base station of this coverage in the coverage of a base station.Because portable terminal has not known whether the base station at this moment, at first attempt receiving from signal of base station to determine whether the base station exists at predetermined channel at initial access phase.In this process, pass through antenna receiving signal.With predetermined gain (being generally less or minimum gain) signal that receives is amplified.Amplifying signal is sampled as digital signal.Digital signal is carried out low-pass filtering.Power according to filtering signal determines whether to exist the base station.If exist, then start method shown in Figure 5.The simple purpose of understanding embodiments of the invention has for convenience illustrated aforesaid operations, and it does not constitute the restriction to embodiments of the invention.

As shown in Figure 5, method is from step 500.In step 502, determine whether to exist the base station.If there is no, then method finishes in step 516.If exist, then send relevant indication in step 504.

In step 506,, obtain sample sequence corresponding to a field and a follow-up symbol from the predetermined time division duplex channel of base station in response to relevant indication.With the 20MHz band width configuration is example, and field length is 153600 Ts, reduces 16 times through sampling, corresponding to 9600 samples.A symbol is corresponding to 128 samples.Can obtain the sample sequence of 9728 samples.

In step 506, relevant with all subsequences in the sample sequence to obtain each correlated results with at least one PSS signal (promptly main synchronizing sequence).Allow three kinds of main synchronizing sequences in the LTE TDD standard.Can use wherein a kind of, two or three main synchronizing sequence according to the agreement of concrete system.According to relevant purpose as can be known, the length of subsequence is identical with the length of main synchronizing sequence.Adjacent subsequence in all subsequences of sample sequence is offset a sample each other.Thereby all subsequences cover whole sample sequence.

With the 20MHz band width configuration is example, PSS (i), i=0, three kinds of main synchronizing sequences of 1,2 expression.PSS (i, k), k=0,1,2 ..., thresholding during 128 of 127 expression i main synchronizing sequences.R represents sample sequence.R (j), j=0,1,2 ..., 9728 samples of 9727 expression sample sequences.

C (i, m) in expression i main synchronizing sequence and the sample sequence from the correlated results of the initial subsequence rs (m) of m sample, wherein

$C(i,m)={|\underset{k=0}{\overset{127}{\mathrm{\&Sigma;}}}r{(k+m)}^{*}\&CenterDot;\mathrm{PSS}(i,n)|}^2---\left(1.1\right)$

Wherein * represents conjugation, m=0, and 1,2 ..., 9599.Should be appreciated that and to utilize other related operation to obtain correlated results.

In this example, for a sample sequence, obtain 9600 correlated results.

In step 506, (i, m), (i, (i, m) normalization obtain the normalization correlated results with correlated results C for the power of the sample of corresponding subsequence rs (m) m) and N (m) according to correlated results C for each C

, wherein

$N\left(m\right)=\underset{k=0}{\overset{127}{\mathrm{\&Sigma;}}}{\left|r(k+m)\right|}^2---\left(2.1\right)$

$\tilde{C}(i,m)=\frac{C(i,m)}{N\left(m\right)}---\left(3.1\right)$

Should be appreciated that and to adopt different power and definition.

In step 508, in response to these correlated results that obtained

, determine the largest correlation result in these correlated results

$\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)=\underset{i,m}{\max }\left\{\tilde{C}(i,m)\right\}---\left(4\right)$

In step 508, at largest correlation result

, calculate and use largest correlation result

Corresponding main synchronizing sequence PSS (i ₀) correlated results that obtains

, m=0,1,2 ..., 9599 peak-to-average force ratio M.

For example, peak-to-average force ratio M can be largest correlation result with correlated results in and largest correlation result adopt the ratio of the average of other correlated results that identical main synchronizing sequence obtains.Particularly,

$M=\frac{\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)}{\frac{1}{9600-1}\underset{m=0,m\&NotEqual;{\mathrm{<figure-callout\; id="0"\; label="m"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">m</figure-callout>}}_0}{\overset{9599}{\mathrm{\&Sigma;}}}\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m)}---\left(5.1\right)$

For example, peak-to-average force ratio M can be a largest correlation result and the ratio of the average of all correlated results that adopt identical main synchronizing sequence to obtain.Particularly,

$M=\frac{\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)}{\frac{1}{9600}\underset{m=0}{\overset{9599}{\mathrm{\&Sigma;}}}\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m)}---\left(5.2\right)$

Should be appreciated that peak-to-average force ratio M can define according to other calculates.

In step 510, determine that whether peak-to-average force ratio M is less than first threshold.If less than (showing that current gain is not suitable for setting up synchronous needs), then send and improve the gain notice in step 512.Otherwise method finishes in step 516.

In step 514, in response to improving gain notice, the gain that improves variable gain amplifier.

Then method finishes in step 516.Step 502,504,510,512 is corresponding to controlled step.

In the above-described embodiments, can suppress the influence of the upward signal of contiguous portable terminal by normalized.

Can make further improvement to portable terminal shown in Figure 4.In this improved embodiment, portable terminal 400 ' comprise relevant apparatus 405 ', measurement mechanism 406 ', control device 407 and gain adjustment device 408 '.Relevant apparatus 405 ' and control device 407 ' comprise the respectively function of relevant apparatus 405 and control device 407.Measurement mechanism 406 ' with gain adjustment device 408 ' identical with measurement mechanism 406 respectively with gain adjustment device 408 functions.The simple purpose of understanding embodiments of the invention for convenience, here also illustrated antenna 401 ', variable gain amplifier (VGA) 402 ', analog to digital converter (A/D) 403 ' and low pass filter (LPF) 404 ', do not constitute restriction to embodiments of the invention.

When the start of portable terminal 400 ' in the coverage of a base station or when entering the coverage of another base station, need to insert the base station of this coverage.Owing to do not known whether the base station portable terminal 400 ' this moment, at first attempted receiving from signal of base station to determine whether the base station exists at predetermined channel at initial access phase.In this process, by antenna 401 ' received signal.VGA 402 ' amplifies the signal that receives with predetermined gain (being generally less or minimum gain).A/D 403 ' is sampled as digital signal with amplifying signal.LPF 404 ' carries out low-pass filtering to digital signal.Unshowned judgment means determines whether to exist the base station according to the power of filtering signal.If exist, then start synchronizing process.

Control device 407 ' indicate to relevant apparatus 405 ' transmission in response to the existence of determining the base station.

Relevant apparatus 405 ' in response to from control device 407 ' indication, obtain sample sequence from the predetermined time division duplex channel of base station corresponding to a field and a follow-up symbol.With the 20MHz band width configuration is example, and field length is 153600 Ts, reduces 16 times through sampling, corresponding to 9600 samples.A symbol is corresponding to 128 samples.Can obtain the sample sequence of 9728 samples.

Relevant apparatus 405 ' relevant with all subsequences in the sample sequence to obtain each correlated results with at least one PSS signal (promptly main synchronizing sequence).Allow three kinds of main synchronizing sequences in the LTE TDD standard.Can use wherein a kind of, two or three main synchronizing sequence according to the agreement of concrete system.According to relevant purpose as can be known, the length of subsequence is identical with the length of main synchronizing sequence.Adjacent subsequence in all subsequences of sample sequence is offset a sample each other.Thereby all subsequences cover whole sample sequence.

With the 20MHz band width configuration is example, PSS (i), i=0, three kinds of main synchronizing sequences of 1,2 expression.PSS (i, k), k=0,1,2 ..., thresholding during 128 of 127 expression i main synchronizing sequences.r _nRepresent n sample sequence.r _n(j), j=0,1,2 ..., 9728 samples of n sample sequence of 9727 expressions.

In this example, for a sample sequence, obtain 9600 correlated results.

Relevant apparatus 405 ' may receive more than once control device 407 ' indication.When receiving when indication once more, relevant apparatus 405 ' once more obtains sample sequence r corresponding to a field and a follow-up symbol from the predetermined time division duplex channel of base station _nCan understand, the field that comprises of the field of the sample sequence of Huo Deing and last sample sequence is adjacent once more.Thereby the follow-up symbol that last sample sequence comprises is first symbol of the field of the sample sequence that obtains once more.

C _n(i, m) in expression i main synchronizing sequence and n the sample sequence from m the subsequence rs that sample is initial _n(m) correlated results, wherein

$C(i,m)={|\underset{k=0}{\overset{127}{\mathrm{\&Sigma;}}}r{(k+m)}^{*}\&CenterDot;\mathrm{PSS}(i,k)|}^2---(1.2)$

Wherein * represents conjugation, m=0, and 1,2 ..., 9599.Should be appreciated that and to utilize other related operation to obtain correlated results.

For each C _n(i, m), relevant apparatus 405 ' according to correlated results C _n(i, corresponding subsequence rs m) _nThe power of sample (m) and N _n(m) with correlated results C _n(i, m) normalization obtain the normalization correlated results

, wherein

$N_n\left(m\right)=\underset{k=0}{\overset{127}{\mathrm{\&Sigma;}}}{\left|r_n(k+m)\right|}^2---(2.2)$

${\tilde{C}}_n(i,m)=\frac{C_n(i,m)}{N_n\left(m\right)}---\left(3.2\right)$

Should be appreciated that and to adopt different power and definition.

Under the unaltered situation of gain, under the current gain based on identical main synchronizing sequence PSS (i) and each sample sequence r _n, n=1 ..., the subsequence rs of the same position m among the N _n(m), m=0,1,2 ..., being correlated with and the power estimation of acquisition between 9599

And or its average

, estimate as the power that is obtained.Particularly,

$\tilde{C}(i,m)=\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\tilde{C}}_n(i,m)---\left(6\right)$ Perhaps

$\tilde{C}(i,m)=\left(\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\tilde{C}}_n(i,m)\right)/N---\left(7\right)$

Be appreciated that if be right after after regulating gain and receive indication, N=1 at this moment then, thereby $\tilde{C}(i,m)={\tilde{C}}_n(i,m).$

Measurement mechanism 406 ' in response to relevant apparatus 405 ' these correlated results of acquisition

, determine the largest correlation result in these correlated results

$\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)=\underset{i,m}{\max }\left\{\tilde{C}(i,m)\right\}---\left(4\right)$

At largest correlation result

, calculate and use largest correlation result

Corresponding main synchronizing sequence PSS (i ₀) correlated results that obtains , m=0,1,2 ..., 9599 peak-to-average force ratio M.

For example, peak-to-average force ratio M can be largest correlation result with correlated results in and largest correlation result adopt the ratio of the average of other correlated results that identical main synchronizing sequence obtains.Particularly,

$M=\frac{\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)}{\frac{1}{9600-1}\underset{m=0,m\&NotEqual;{\mathrm{<figure-callout\; id="0"\; label="m"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">m</figure-callout>}}_0}{\overset{9599}{\mathrm{\&Sigma;}}}\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m)}---\left(5.1\right)$

For example, peak-to-average force ratio M can be a largest correlation result and the ratio of the average of all correlated results that adopt identical main synchronizing sequence to obtain.Particularly,

$M=\frac{\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)}{\frac{1}{9600}\underset{m=0}{\overset{9599}{\mathrm{\&Sigma;}}}\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m)}---\left(5.2\right)$

Should be appreciated that peak-to-average force ratio M can define according to other calculates.

Control device 407 ' surpass under the situation of second threshold value less than first threshold (this shows that current gain is not suitable for setting up synchronous needs) and based on the number of times of current gain relevant apparatus 405 ' acquisition sample sequence at peak-to-average force ratio M, notice gain adjustment device 408 '.

In addition, control device 407 ' surpass under the situation of second threshold value less than first threshold and based on the number of times of current gain relevant apparatus 405 ' acquisition sample sequence at peak-to-average force ratio M is indicated to relevant apparatus 405 ' transmissions.

Gain adjustment device 408 ' in response to control device 407 ' the notice gain that improves variable gain amplifier.

Fig. 6 is the flow chart of improving one's methods that illustrates according to the method for ride gain in the portable terminal of the embodiment of the invention, and this portable terminal is applicable to the system based on 3GPP LTE.

When portable terminal is started shooting or entered the coverage of another base station, need to insert the base station of this coverage in the coverage of a base station.Because portable terminal has not known whether the base station at this moment, at first attempt receiving from signal of base station to determine whether the base station exists at predetermined channel at initial access phase.In this process, pass through antenna receiving signal.With predetermined gain (being generally less or minimum gain) signal that receives is amplified.Amplifying signal is sampled as digital signal.Digital signal is carried out low-pass filtering.Power according to filtering signal determines whether to exist the base station.If exist, then start method shown in Figure 6.The simple purpose of understanding embodiments of the invention has for convenience illustrated aforesaid operations, and it does not constitute the restriction to embodiments of the invention.

As shown in Figure 6, method is from step 600.In step 602, determine whether to exist the base station.If there is no, then method finishes in step 616.If exist, then send relevant indication in step 604.

In step 606, in response to receiving relevant indication, obtain sample sequence corresponding to a field and a follow-up symbol from the predetermined time division duplex channel of base station.With the 20MHz band width configuration is example, and field length is 153600 Ts, reduces 16 times through sampling, corresponding to 9600 samples.A symbol is corresponding to 128 samples.Can obtain the sample sequence of 9728 samples.

In step 606, relevant with all subsequences in the sample sequence to obtain each correlated results with at least one PSS signal (promptly main synchronizing sequence).Allow three kinds of main synchronizing sequences in the LTE TDD standard.Can use wherein a kind of, two or three main synchronizing sequence according to the agreement of concrete system.According to relevant purpose as can be known, the length of subsequence is identical with the length of main synchronizing sequence.Adjacent subsequence in all subsequences of sample sequence is offset a sample each other.Thereby all subsequences cover whole sample sequence.

With the 20MHz band width configuration is example, PSS (i), i=0, three kinds of main synchronizing sequences of 1,2 expression.PSS (i, k), k=0,1,2 ..., thresholding during 128 of 127 expression i main synchronizing sequences.r _nRepresent n sample sequence.r _n(j), j=0,1,2 ..., 9728 samples of n sample sequence of 9727 expressions.

In this example, for a sample sequence, obtain 9600 correlated results.

May receive relevant indication more than once.When receiving relevant indication once more, obtain sample sequence r from the predetermined time division duplex channel of base station once more corresponding to a field and a follow-up symbol _nCan understand, the field that comprises of the field of the sample sequence of Huo Deing and last sample sequence is adjacent once more.Thereby the follow-up symbol that last sample sequence comprises is first symbol of the field of the sample sequence that obtains once more.

C _n(i, m) in expression i main synchronizing sequence and n the sample sequence from m the subsequence rs that sample is initial _n(m) correlated results, i.e. correlated results, wherein

$C_n(i,m)={|\underset{k=0}{\overset{127}{\mathrm{\&Sigma;}}}{r}_n{(k+m)}^{*}\&CenterDot;\mathrm{PSS}(i,k)|}^2---(1.2)$

Wherein * represents conjugation, m=0, and 1,2 ..., 9599.Should be appreciated that and to utilize other related operation to obtain correlated results.

In step 606, for each C _n(i, m), according to correlated results C _n(i, corresponding subsequence rs m) _nThe power of sample (m) and N _n(m) with correlated results C _n(i, m) normalization obtain the normalization correlated results

, wherein

$N_n\left(m\right)=\underset{k=0}{\overset{127}{\mathrm{\&Sigma;}}}{\left|r_n(k+m)\right|}^2---(2.2)$

${\tilde{C}}_n(i,m)=\frac{C_n(i,m)}{N_n\left(m\right)}---\left(3.2\right)$

Should be appreciated that and to adopt different power and definition.

In step 606, under the unaltered situation of gain, under the current gain based on identical main synchronizing sequence PSS (i) and each sample sequence r _n, n=1 ..., the subsequence rs of the same position m among the N _n(m), m=0,1,2 ..., being correlated with and the correlated results of acquisition between 9599

And or its average

, as the correlated results that is obtained.Particularly,

$\tilde{C}(i,m)=\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\tilde{C}}_n(i,m)---\left(6\right)$ Perhaps

$\tilde{C}(i,m)=\left(\underset{n=1}{\overset{N}{\mathrm{\&Sigma;}}}{\tilde{C}}_n(i,m)\right)/N---\left(7\right)$

Be appreciated that if be right after after regulating gain and receive indication, N=1 at this moment then, thereby $\tilde{C}(i,m)={\tilde{C}}_n(i,m).$

In step 608, in response to these correlated results that obtained

, determine the largest correlation result in these correlated results

$\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)=\underset{i,m}{\max }\left\{\tilde{C}(i,m)\right\}---\left(4\right)$

In step 608, at largest correlation result

, calculate and use largest correlation result

Corresponding main synchronizing sequence PSS (i ₀) correlated results that obtains

, m=0,1,2 ..., 9599 peak-to-average force ratio M.

For example, peak-to-average force ratio M can be largest correlation result with correlated results in and largest correlation result adopt the ratio of the average of other correlated results that identical main synchronizing sequence obtains.Particularly,

$M=\frac{\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)}{\frac{1}{9600-1}\underset{m=0,m\&NotEqual;{\mathrm{<figure-callout\; id="0"\; label="m"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">m</figure-callout>}}_0}{\overset{9599}{\mathrm{\&Sigma;}}}\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m)}---\left(5.1\right)$

For example, peak-to-average force ratio M can be a largest correlation result and the ratio of the average of all correlated results that adopt identical main synchronizing sequence to obtain.Particularly,

$M=\frac{\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m_0)}{\frac{1}{9600}\underset{m=0}{\overset{9599}{\mathrm{\&Sigma;}}}\tilde{C}({\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="HSA00000023521100061.png"\; state="\{\{state\}\}">i</figure-callout>}}_0,m)}---\left(5.2\right)$

Should be appreciated that peak-to-average force ratio M can define according to other calculates.

In step 610, determine that whether peak-to-average force ratio M is less than first threshold.If less than (showing that current gain is not suitable for setting up synchronous needs), then determine in step 611 whether the number of times that obtains sample sequence based on current gain surpasses second threshold value.If surpass, then send and improve the gain notice in step 612.Otherwise return step 604.

In step 614, in response to improving gain notice, the gain that improves variable gain amplifier.

Then method finishes in step 616.Step 602,604,610,611,612 is corresponding to controlled step.

In above-mentioned improvement embodiment, by merging the influence that correlated results can suppress Gaussian noise.

Preferably, can definite next that will bring up to gain before the gain that improves variable gain amplifier, whether next gain that promptly is higher than current gain is lower than the 3rd threshold value.If be lower than, then the gain of variable gain amplifier is brought up to described next gain.

Fig. 7 is the schematic diagram that the effect that reaches by normalization is shown.Fig. 7 (A) shows the correlated results that obtains by conventional method, wherein is the power of upward signal in the frame of broken lines, obvious power greater than PSS signal between the left side sample 200 to 400, thus influenced correlated results.Fig. 7 (B) shows and adopts the resulting correlated results of normalized of the present invention, be the upward signal power that obviously is inhibited in the frame of broken lines wherein, and the power of PSS signal is more obvious between the left side sample 200 to 400.

With reference to specific embodiment the present invention has been described in the specification in front.Yet those of ordinary skill in the art understands, and can carry out various modifications and change under the prerequisite that does not depart from the scope of the present invention that limits as claims.

Claims (8)

1. a portable terminal is applicable to the system that plans Long Term Evolution based on third generation partner, comprising:

Relevant apparatus, in response to indication from control device, obtain sample sequence from the predetermined time division duplex channel of base station corresponding to a field and a follow-up symbol, and relevant to obtain each correlated results with at least one main synchronizing sequence with all subsequences in the described sample sequence;

Measurement mechanism in response to the correlated results that is obtained, at the largest correlation result in the described correlated results, calculates the peak-to-average force ratio of the correlated results of the corresponding main synchronizing sequence acquisition of using described largest correlation result;

Described control device sends described indication in response to the existence of determining the base station to described relevant apparatus, and at least under the situation of described peak-to-average force ratio less than first threshold, the notice gain adjustment device; With

Gain adjustment device, in response to the gain of described notice raising variable gain amplifier,

Wherein, described relevant apparatus is also according to the power of the sample of the corresponding subsequence of each described correlated results with described correlated results normalization.

2. portable terminal as claimed in claim 1, wherein

Described control device further is configured to,

Surpass under the situation of second threshold value less than first threshold and based on the number of times that current gain relevant apparatus obtains sample sequence at described peak-to-average force ratio, notify described gain adjustment device; And

Do not surpass under the situation of second threshold value less than first threshold and described number of times at described peak-to-average force ratio, send described indication to relevant apparatus, and

Described relevant apparatus further is configured to not change and obtain from the predetermined time division duplex channel of described base station once more under the situation corresponding to the sample sequence of a field and a follow-up symbol in gain, the correlated results that obtains based on relevant between the subsequence of the same position in identical main synchronizing sequence and each sample sequence under the current gain and or its average, as the correlated results that is obtained.

3. portable terminal as claimed in claim 1 or 2, wherein said peak-to-average force ratio be described largest correlation result with described correlated results in and described largest correlation result adopt the ratio of the average of other correlated results that identical main synchronizing sequence obtains, or the ratio of described largest correlation result and the average of all correlated results that adopt identical main synchronizing sequence acquisition.

4. portable terminal as claimed in claim 1 or 2, wherein said gain adjustment device further are configured to be lower than under the situation of the 3rd threshold value in next gain that is higher than current gain, and described next gain is brought up in the gain of variable gain amplifier.

5. the method for ride gain in the portable terminal, described portable terminal is applicable to the system that plans Long Term Evolution based on third generation partner, described method comprises:

Correlation step, in response to relevant indication, obtain sample sequence from the predetermined time division duplex channel of base station corresponding to a field and a follow-up symbol, and relevant to obtain each correlated results with at least one main synchronizing sequence with all subsequences in the described sample sequence;

Measuring process in response to the correlated results that is obtained, at the largest correlation result in the described correlated results, calculates the peak-to-average force ratio of the correlated results of the corresponding main synchronizing sequence acquisition of using described largest correlation result;

Controlled step provides described relevant indication in response to the existence of determining the base station, and at least under the situation of described peak-to-average force ratio less than first threshold, provides and improve the gain notice; With

The gain-adjusted step, in response to the gain of described raising gain notice raising variable gain amplifier,

Wherein, described correlation step also comprises according to the power of the sample of the corresponding subsequence of each described correlated results with described correlated results normalization.

6. method as claimed in claim 5, wherein

Described controlled step also comprises:

Surpass under the situation of second threshold value less than first threshold and based on the number of times that current gain obtains sample sequence at described peak-to-average force ratio, described raising gain notice is provided; And

Do not surpass under the situation of second threshold value less than first threshold and described number of times at described peak-to-average force ratio, described relevant indication is provided, and

Under described correlation step is included in also that gain does not change and obtains situation corresponding to the sample sequence of a field and a follow-up symbol from the predetermined time division duplex channel of described base station once more, the correlated results that obtains based on relevant between the subsequence of the same position in identical main synchronizing sequence and each sample sequence under the current gain and or its average, as the correlated results that is obtained.

7. as claim 5 or 6 described methods, wherein said peak-to-average force ratio be described largest correlation result with described correlated results in and described largest correlation result adopt the ratio of the average of other correlated results that identical main synchronizing sequence obtains, or the ratio of described largest correlation result and the average of all correlated results that adopt identical main synchronizing sequence acquisition.

8. as claim 5 or 6 described methods, wherein said gain-adjusted step also is included in next gain that is higher than current gain and is lower than under the situation of the 3rd threshold value, and described next gain is brought up in the gain of variable gain amplifier.

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