CN101874392A - Pn phase recovery in a DMB-T system - Google Patents

Abstract

A PN Phase Recovery (PPR) method is used to acquire PN sequence phase synchronization in a system such as DMB-T. The time offset of the positions of the basic PN sequence in successive signal frames is estimated robustly. An accurate decision of the signal frame index is made based on multiple time offsets measured in the successive signal frames through a voting mechanism with modest calculation complexity.

Description

PN phase bit recovery in the DMB-T system

Background technology

Domain Synchronous OFDM (TDS-OFDM) is a kind of basic physical layer scheme of the DMB-T standard of Chinese terrestrial broadcasting, wherein, uses the multiplexed frame structure as illustrated in fig. 2.This frame structure is very important for the time synchronized in the DMB-T receiver.

Signal frame is the elementary cell of multiplexed frame structure.As shown in Figure 3, signal frame comprises two time-domain signal parts, i.e. frame head and frame.Frame head has identical baseband signalling data transfer rate (7.56Msym/sec) with frame.In the signal frame head, for synchronously and channel estimating and send the PN sequence.Simultaneously, the PN frame head also replaces traditional Cyclic Prefix (CP), serves as the guard time interval of the OFDM frame of back.

Length is L _PNThe PN header comprise three parts: length is N _PNThe complete period of the PN sequence of individual symbol, length are L _PrePN preamble and length be L _PostThe PN postamble.In standard, defined three types signal frame option with different parameter combinations.

In type 2, in each frame, use the same section of PN sequence, this makes the PN Phase synchronization than the Class1 that sends different PN sequences in the unlike signal frame and 3 easier.

Employed PN sequence changes between frame in the signal frame.For sample frequency and sampling time phase place synchronously for, and for channel estimating, must know employed PN sequence in each frame.In addition, in whole receiving course, must keep the PN sequence phase synchronous.As described herein, the purpose of PN phase bit recovery (PPR) is under the reception data conditions of given sampling in a plurality of signal frame heads, discerns the index f of f signal frame.

In awgn channel, if in the current demand signal frame, at time t ₁There is the peak value of coherent signal in the place, and in the next signal frame, can be at time t ₂The place finds another peak value of correlated results, and then the distance between these two peak values is the function of frame index, thereby can determine the index of signal frame.

Yet receiver can be always operating in the awgn channel.Radio channel may experience serious decline and strong jamming.In TDS-OFDM, especially when the length of multipath channel is longer, disadvantageously, OFDM frame part may be divided with frame header and be disturbed.Because correlation peak is not always correctly determined in possible very noisy and interference easily.Because the PN phase place changes between frame, so traditional become impossible to suppress noise and interference at a plurality of continuous signal frame inner averages or the correlated results that adds up.

Sampling frequency offset makes that the measurement of the time difference between two peak values is difficult more.If adopt low-cost crystal, then may there be bigger sampling frequency offset.In the digital processing receiver, the sampling of using received signal is carried out above-mentioned relevant.Big sampling frequency offset will increase the difficulty of PN phase bit recovery, because determine that based on the analysis of sampled data in the frame head, big sampling frequency offset will cause uncertainty in basis.

In order to obtain correct information as soon as possible, need catch the PN phase place as early as possible about the signal frame index.Yet in the stage that receiver is started working, receiver is scarcely acquainted with radio channel.Therefore, fast and robust catch the PN phase place, in abominable wireless environment, be a kind of challenge especially.

Summary of the invention

Described PN phase bit recovery (PPR) method and apparatus, it is synchronous to be used for obtaining the PN sequence phase in the system such as DMB-T, and wherein the time offset of the position of basic PN sequence in the continuous signal frame is estimated on robust ground.By the lower voting mechanism of computation complexity,, carry out accurate judgement to the signal frame index based on a plurality of time offset of in the continuous signal frame, measuring.In this manner, the DMB-T receiver is robust more, even and in the extremely low environment of signal to noise ratio or exist under the situation of big sampling frequency offset, also can be synchronous with transmitter on the PN sequence phase apace.

With reference to the accompanying drawings, under the situation of the detailed description of the one exemplary embodiment that reading and understanding are following, can understand further feature and advantage, provide brief description of drawings below

Description of drawings

Fig. 1 is the figure that wherein can use DMB-T receiver of the present invention.

Fig. 2 shows the figure of the multiplexed frame structure of DMB-T.

Fig. 3 shows the figure of the structure of signal frame.

Fig. 4 shows the figure of the PN phase pushing figure of the signal frame in the superframe.

Fig. 5 is the block diagram of time offset estimator.

Fig. 6 shows the planisphere that is used to obtain about the information of signal frame index.

Fig. 7 is the block diagram of PN phase bit recovery module.

Embodiment

Below the present invention is described in more detail.Person of skill in the art will appreciate that following detailed description only is schematically, and never means restriction.Other embodiments of the invention are conspicuous for benefiting from those skilled in the art of the present disclosure.The present embodiment of the invention shown in reference to the accompanying drawings at length.In whole accompanying drawings and following detailed description, use identical Reference numeral to indicate same or analogous parts.

Fig. 1 shows the general structure of DTV receiver.Signal is received by RF module (not shown), and is sampled in ADC 105.Sampled signal 107 is imposed on digital front-end 109, and digital front-end 109 is in response to carrying out synchronously from the information 110 of synchronization blocks 111.This synchronization blocks is carried out and is calculated, and for example PN phase bit recovery 111a, carrier shift amount are recovered 111b, the symbol offset amount recovers 111c and sample frequency is recovered 111d to enable.The output signal 113 of digital front-end 109 is imposed on synchronization blocks 111 and channel estimating and equalization block 115, and channel estimating and equalization block offer synchronization blocks 111 by circuit 117 and 119 from synchronization blocks 111 received signals and with signal respectively.The output signal 121 of channel estimating and balance module is imposed on decoder 123, and decoder 123 is decoded and is exported reception information 125.

The present invention mainly pays close attention to PN phase bit recovery (111a).

With reference to Fig. 2 and Fig. 3, in the DMB-T of Chinese terrestrial broadcasting standard, F signal frame arranged in superframe.PN (f, i), i=0,1 ..., L _PNThe-1st, be used for the PN sequence of f signal frame of superframe.

In standard, defined three types signal frame option with the different parameters combination.Table 1 has been listed three types parameter.

Table 1: the parameter of three types of signal frame heads

Type	??L PN	??N PN	??L pre	??L post	??L OFDM	??F	PN in each signal frame is identical
								?1：?PN420	??420	??255	??82	??83	??3780	??225	Not

Type	??L PN	??N PN	??L pre	??L post	??L OFDM	??F	PN in each signal frame is identical
								?2：?PN595	??595	??1024	??0	??0	??3780	??216	Be
?3：?PN945	??945	??511	??217	??217	??3780	??200	Not

In type 2, in each frame, use the same section of PN sequence, this makes the PN Phase synchronization be more prone to than the Class1 and 3 that sends different PN sequences in the unlike signal frame.The present invention pays close attention to Class1 and 3 PN bit recovery mutually.Class1 and 3 is similar; To be that example is demonstrated with Class1 (PN420).

Can be with employed PN sequence definition in f the signal frame PN (f, i), i=0,1 ..., L _PN-1.In PN 420 sequences, L _PN=420.According to the DMB-T standard, for the PN420 sequence, employed PN sequence is from the m sequence, and for each signal frame of superframe, has specific initial phase in LFSR PN generator.Can be in LFSR with initial phase " 10110000 " (binary number) produce PN sequence PN in the 0th signal frame (0, i).Employed different PN sequences have some inner link in F the signal frame.

Can be with basic PN sequence P ₀(i) be defined as satisfied

P ₀(i)＝PN(0，i+82)??i＝0，1，...，N-1????????????(1)

Wherein N is the cycle of m sequence.For PN420, N=255.Employed all PN sequences in the unlike signal frame can be used as basic PN sequence P ₀(i) derivative.For the signal frame in the superframe listed in the DMB-T standard, according to the analysis to the initial phase of LFSR, employed length is that 420 PN sequence can be as shown in the formula generation in f signal frame

PN(f，i)＝P ₀([i-O(f)-82]modN)，i＝0，1，...，L _PN-1????(2)

Wherein O (f) is the variable PN phase pushing figure at f signal frame.Can use following formula to calculate O (f)

$O\left(f\right)=\mathrm{int}\left[\frac{112-|112-f|+1}{2}\right]\·{(-1)}^f,$ f＝0，1，...，F-1????????????(3)

Fig. 4 has not gone out O (f).

Employed PN sequence will change between different frame in the signal frame.For sample frequency and sampling time phase place synchronously for, and for channel estimating, must know employed PN sequence in each frame.In addition, in whole receiving course, must keep the PN sequence phase synchronous.As described herein, the purpose of PN phase bit recovery (PPR) be in given sampling under the reception data conditions of a plurality of signal frame heads, discern the index f of f signal frame.

In continued time domain, near f following the providing of received signal that the signal frame head is:

$z(f,t)=\left[\mathrm{\ΣPN}(f,i)\mathrm{\δ}(t-{\mathrm{iT}}_s)\right]\⊗g\left(t\right)+n\left(t\right)$

(4)

$\left[\mathrm{\Σ}{P}_0\left(i\right)\mathrm{\δ}(t-{\mathrm{iT}}_s)\right]\⊗\mathrm{\δ}(t-[82+O\left(f\right)\left]\right)\⊗g\left(t\right)+n\left(t\right)$

Wherein g (t) is the impulse response of equivalent channel of combination, comprises the effect of SRRC pulse shaping filter at transmitter and receiver place and the effect of radio channel.Following the providing of impulse response g (t):

$g\left(t\right)=\mathrm{SRRC}\left(t\right)\⊗h\left(t\right)\⊗\mathrm{SRRC}\left(t\right)=\mathrm{RC}\left(t\right)\⊗h\left(t\right)---\left(5\right)$

Wherein RC (t) is the impulse response function of raised cosine filter, and SRRC (t) is the impulse response function of square root raised cosine filter,

Be channel impulse response functions, and n (t) is the AWGN noise.

Receiver calculates and receives data sampling and local basic PN sequence P ₀Being correlated with (i).In continued time domain, this is correlated with and is

$R\left(t\right)=R_0\left(t\right)\⊗g\left(t\right)\⊗\mathrm{\δ}(t-[82+O\left(f\right)]T_s-f{L}_F{T}_s)+w\left(t\right)---\left(6\right)$

R wherein ₀(t)=∑ R ₀(k) δ (t-kT _s).R ₀(k) be P ₀(k) auto-correlation function, and only when k=0, have very large value.

In awgn channel, at time t ₁There is the peak value of coherent signal in the place,

t ₁＝(82+O(f)+fL _F)T _s+Δ ₀????????????????(7)

Δ wherein ₀It is constant time reference.In next signal frame, can be at t ₂=(82+O (f+1)+(f+1) L _F) T _s+ Δ ₀The place finds another peak value of correlated results.Distance between these two peak values is the function of frame index, thereby can determine the index of signal frame.

Yet as mentioned above, receiver can be always operating in the awgn channel.Radio channel may experience serious decline and strong jamming.In TDS-OFDM, especially when the length of multipath channel is longer, disadvantageously, OFDM frame part may be divided with frame header and be disturbed.Because relevant peak value is not always correctly determined in possible very noisy and interference easily.Because the PN phase place changes between frame, so traditional become impossible to suppress noise and interference at a plurality of continuous signal frame inner averages or the correlated results that adds up.

In addition, sampling frequency offset makes that the measurement of the time difference between two peak values is difficult more.If adopt crystal cheaply, then may there be bigger sampling frequency offset.In the digital processing receiver, will use the sampling of received signal to carry out above-mentioned relevant R (t).

If ignore the effect of limited PN length, then the R as a result (k) of this digital correlation with sample the same to continuous time signal R (t):

R(k)＝R(kT _s+ε)????????????????????????????(8)

Wherein ε is the data sampling time shift, and ε=ε ₀+ f. Δ .T _sComprise two parts: the reference point of initially sampling ε ₀Sampling time error with the accumulation that causes owing to sampling frequency offset.If sampling frequency offset is

(f _s' be sample frequency, f _sBe the sample frequency of the regulation of aliging with transmitter), then the sampling time error of being accumulated in a signal frame is L _F* df*T _sL _FBe with T _sLength for the signal frame of unit; In the signal of PN420 type, L _F=4200.

Big sampling frequency offset will increase the difficulty of PN phase bit recovery, because determine that based on the analysis of sampled data in the frame head, big sampling frequency offset will cause uncertainty in basis.

In order to obtain correct information as soon as possible, need catch the PN phase place as early as possible about the signal frame index.Yet in the stage that receiver is started working, receiver is scarcely acquainted with radio channel.Therefore, fast and robust catch the PN phase place, in abominable wireless environment, be a kind of challenge especially.

In the exemplary embodiment, use two main modular to realize PN phase bit recovery.A module is carried out the time offset of basic PN sequence in two continuous signal frames is estimated (TOE).Another module is the determination module of decision signal frame index.

1. the measurement of the time offset of basic PN sequence

Being correlated with of header portion by finding two continuous signal frames carried out the measurement to the time offset of basic PN sequence, and this is expressed as follows:

${\mathrm{RR}}_f\left(t\right)=z(f,t)\⊕z(f+1,t)---\left(9\right)$

Wherein

Expression related operation symbol.After some mathematic(al) manipulations, have

${\mathrm{RR}}_f\left(t\right)=R_0\left(t\right)\⊗R_0\left(t\right)\⊗g\left(t\right)\⊗g\left(t\right)\⊗$

(10)

δ(t-[O(f+1)-O(f)]T _s-L _FT _s)+u(t)

Wherein

Roughly be the ripple of pulse shape, u (t) is a noise item.No matter be which kind of wireless channel, signal path or multipath, amount

Has the highest peak value at the t=0 place.

As mentioned above, when handling digital sample, the sampling time error of being accumulated in the signal frame must considering to cause owing to sampling frequency offset, and this be receiver this stage ignorant.It can be expressed as τ _f=Δ T _sCan be as finding strong peak value near the sampled signal the upper/lower positions relevant:

t _f＝[O(f+1)-O(f)]T _s+L _FT _s+τ _f+e????????????(11)

Wherein e is a measure error.Value t _fIndicated the distance between the identical PN section in two continuous signal frames, index that also can the index signal frame.

Fig. 5 shows the block diagram of the time offset estimator (TOE) 500 that is used for time of implementation side-play amount estimation.Received signal sampling 501 is imposed on first related blocks 503, buffer 505 and second related blocks 507.Be used to produce basic PN sequence P ₀Generator 502 link to each other with related blocks 503 so that at received signal sampling 501 and basic PN sequence P ₀Between carry out relevant.The result of this associative operation has determined peak value t correlation time ₁, and definite which part that will in associative operation subsequently, use the received signal sampling that is stored in the buffer 505.Related blocks 503 links to each other with buffer 505, so that carry out this selection.The selected portion of received signal sampling postpones a signal frame by delay cell 509.Related blocks 507 carries out that another is relevant then, is specifically to carry out between the selected portion of the received signal sampling of the received signal sampling of present frame and former frame.The result of this associative operation has determined peak value t correlation time ₂Then, time offset computing block 511 is according to difference t ₂-t ₁Come side-play amount t computing time _f

Time offset estimator (TOE) has been realized the series of steps that repeats in each frame, it is summarized as follows.

Calculate f signal frame head and basic PN sequence P ₀Being correlated with between the signal (i)

$R_1\left(k\right)=\underset{i=0}{\overset{N-1}{\mathrm{\Σ}}}z(f,k\frac{T_s}{2}+i{T}_s)P_0\left(i\right)$

Wherein N is the cycle of basic PN sequence.(for PN420, N=255)

Search for significant correlation peak.

R _max＝max{|R ₁(i)|}

With R ₁(i) be stored among the S (i) S (i)=R ₁(i)

Dead circuit is set directly gathers φ.

If any, find the path with ceiling capacity, it is greater than R _MaxTh ₁, (threshold value th for example ₁=0.5)

$i^{*}=\underset{\left|S\left(i\right)\right|>R_{\max }\·{\mathrm{th}}_1}{\arg \max }\left\{\right|S\left(i\right)\left|\right\}$

If do not have the path greater than R _MaxTh ₁, then advance to (g)

Make S (i ^*)=0, S (i ^*± 1)=0, S (i ^*± 2N)=0, S (i ^*± 2N ± 1)=0

In this step,, then force its relevant portion to make zero to avoid unnecessary redundancy if in result's mid portion, search for particular path.With index i ^*The result carry out relevant with the following result who forces to make zero: i ^*+/-1, i ^*The 1+ of+/-/-2N, i ^*The 2N of+/-.

With { i ^*Add set of paths φ to, forward step (d) to

Element among the pair set φ is chosen, and obtains { i ₁, i ₂...., i _L}

The storage overlay length is L _c=[2N+ (i _L-i ₁)] T _sData segment, wherein the time started of the record of this section point is t ₁=i ₁* T _s/ 2, promptly

K=0,1,2 ..., L _c-1

In n+1 signal frame, calculate D (k) with

Between relevant, that is:

$R_2\left(i\right)=\underset{i=0}{\overset{L_c-1}{\mathrm{\Σ}}}z(f+1,i\frac{T_s}{2}+k\frac{T_s}{2})D\left(k\right)$

Find the integer position of correlation peak

$I_2=\underset{i}{\arg \max }\left\{\right|R_2\left(i\right)\left|\right\}$

And write down the time to peak point of this section

${\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HPA00001141482500041.png,HPA00001141482500042.png"\; state="\{\{state\}\}">t</figure-callout>}}_2=I_2\frac{T_s}{2}+c_0\frac{R_2(I_2+1)-R_2(I_2-1)}{R_2\left(I_2\right)}{T}_s$

C wherein ₀It is the constant that is used for the calibration of time detector.(c ₀＝0.387)

Computing time side-play amount t _f=t ₂-t ₁

2. determine the index of the signal frame in the superframe

Defined nucleotide sequence Q (f) makes Q (f)=O (f+1)-O (f).According to (3), after some operation

$Q\left(f\right)=\left\{\begin{array}{cc}f\&CenterDot;{(-1)}^f& f\&Element;\left[\mathrm{0,112}\right]\\ (255-f)\&CenterDot;{(-1)}^f& f\&Element;\left[\mathrm{113,224}\right]\end{array}\right.$

Based on (7), the time offset of the PN sequence in two continuous signal frames is t in theory _f=[Q (f)] T _s+ L _FT _s+ τ _f+ e.Because Q (f) is a mapping function one to one, if can ignore τ _f, e, then utilize the t measured _fCan determine the index f of signal frame.Yet receiver may experience very noisy and interference.Simultaneously, also may there be sampling frequency offset, in time measurement, introduces big value τ _fTherefore, only can carry out determining of accurate and robust according to repeatedly measuring in a plurality of continuous signal frames.

Suppose and in the signal frame of continuous N+1, measured M time offset t _F+m, m=0 wherein, 1,2 ..., M-1.In this index detection problem, there be F supposition.If use traditional minimum range method, then

$f^{*}=\underset{f}{\arg \min }\left\{\underset{m}{\mathrm{\&Sigma;}}{[t_{f+m}-Q(f+m)-L_F{T}_s]}^2\right\}---\left(12\right)$

Because the error τ that comes the error e of self noise and interference and cause owing to sampling frequency offset _fBe not and the similar noise of AWGN noise, so minimum range detects not necessarily best detection method.In addition, because too much hypothesis, the amount of calculation that makes minimum range detect is not little.

Therefore a kind of alternative detection method is described.For this method of illustration clearly, consider the situation of four continuous signal frames.In first three continuous signal frame, can measure two time offset, that is:

T _f＝t _f-L _FT _s＝[Q(f)]T _s+τ ₀+e ₀

(13)

T _f+1＝t _f+1-L _FT _s＝[Q(f+1)]T _s+τ ₁+e ₁

Order

${\mathrm{<figure-callout\; id="1"\; label="D\; f"\; filenames="HPA00001141482500041.png"\; state="\{\{state\}\}">D</figure-callout>}}_f^{}=T_{f+1}-T_f---\left(14\right)$

If at T _F+1And T _fIn do not have noise or error, then for each signal frame f, exist unique to (T _F+1, T _f).Therefore two time offset of continuous signal frame are put into a centering, use this then determining the index f of signal frame.For illustration, in Fig. 6, drawn in two dimensional surface that this is right.For information " f ", to (T _F+1, T _f) be similar to the planisphere point.Will be to (T _F+1, T _f) be shown asterisk, and its other numeral is the index of signal frame.For example, begin with the signal frame of index for " 0 ", this is to being (1,2).In other words, the time offset between signal frame 0 and the signal frame 1 is-1, and the time offset between signal frame 1 and the signal frame 2 is 2.When coming index for the signal frame of " 1 ", this is to being (2 ,-3).This expression: the time offset between signal frame 1 and the signal frame 2 is 2, and the time offset between signal frame 2 and the signal frame 3 is-3.Fig. 6 has only drawn the sub-fraction of planisphere point.Other point is not shown.Find the both sides of planisphere point symmetry ground distribution online " y=-x ".

The variable of from measurement result, deriving Help to determine target planisphere point is positioned at which zone (" y=x " is parallel with line).Because the short-term stability character of sample frequency is so can suppose τ ₀≈ τ ₁Therefore, for

, can avoid the major part influence of sampling frequency offset.Therefore, to the robust more of determining in zone.Based on to the determining of zone, can determine two candidates' planisphere point, that is: S (1)={ f ₁(1), f ₂(1) }.

For ensuing three signal frames, can obtain similar results.

T _f+1＝t _f+1-L _FT _s＝[Q(f+1)]T _s+τ ₁+e ₁

T _f+2＝t _f+2-L _FT _s＝[Q(f+2)]T _s+τ ₂+e ₂

Can judge two other candidate, S (2)={ f ₁(2)-1, f ₂(2)-1}.

There is crossover between S (1) and the S (2).Therefore, final decision is

f ^*＝{S(1)}∩{S(2)}

Certainly, in the testing process of PN phase place, can comprise the time offset of more a plurality of measurements, to realize the detection of robust.The Measuring Time side-play amount that comprises is many more, and the then final confidence level that detects is high more.

Fig. 7 shows the block diagram of PN phase bit recovery (PPR) module.Will from side-play amount continuous time of time offset estimator 500 estimate to impose on continuous delay unit 701,703,705 ..., 70x.Provide respective number dispenser (slicer) 711,713,715 ..., 71x.Each dispenser receive delay the time offset of a signal frame estimate different right, and with these on the planisphere that is mapped to Fig. 6.The output of separator is applied to ballot device 721, estimates f to produce final time offset ^*

Overview of steps performed in the PPR module is as follows:

In a continuous N signal frame, measure M-1 time offset

T _f+0，T _f+1，...，T _f+M-2

S is set to empty set.

In dispenser: from m=0 to m=M-2, circulation a), b), c),

Calculate Γ=T _F+m+1-T _F+m

$K=\mathrm{int}\left[\frac{\mathrm{\&Gamma;}-1}{4}\right]$

V＝4K+1

(if V＞0) then { n ₁=(V-1)/4, n ₂=2*n ₁+ 1} otherwise { n ₁=-1* (V+3)/4, n ₂=2*n ₁}

a ₁=(n ₂-1-m+F) mod F and a ₂=(F-1-n ₂-1-m+F) mod F

With { a ₁, a ₂Add in the S set

In S set, find the element f of normal appearance ^*If number of times p surpasses predetermined threshold p _TH, then can think and finish PN phase bit recovery.Otherwise, will continue testing process, comprise more a plurality of signal frames and more a plurality of time offset that measures.

Except the performance of robust, the said method computation complexity is lower.

Although describe embodiments of the invention in detail, should be appreciated that, under the prerequisite of the spirit and scope of the present invention that do not deviate from claims and limited, can carry out various changes, replacement and variation.

Claims (16)

1. the time offset of the public PN section between the signal section of the subsequent frame that the second relevant PN sequence in the use PN sequence family is encoded in the signal section of the frame that a PN sequence of using in the transmission signals in the PN sequence family is encoded and this transmission signals is carried out estimation approach, the one PN sequence and the 2nd PN sequence all comprise described public PN section, in order to pass on the information about transmission signals, described method comprises described time offset by transmission signals:

The PN sequence characteristic of carrying out PN sequence family first relevant with corresponding between the received signal of transmission signals;

Analyze the first relevant result;

Storage is selected a part of received signal based on the first relevant result;

Execution second relevant between the received signal during the described subsequent frame and a part of received signal of being stored;

Come side-play amount estimated time based on the second relevant correlation peak; And

Service time, side-play amount obtained the indication about the information of transmission signals.

2. method according to claim 1, wherein, described information is the signal frame index.

3. method according to claim 1 wherein, based on the time from the first relevant significant correlation peak value that obtains, is selected a part of received signal of being stored.

4. method according to claim 1 wherein, when determining from the first relevant significant correlation peak value that obtains, suppresses circulation and repeats.

5. method according to claim 1 comprises: use a plurality of time migration values to obtain indication about the information of transmission signals.

6. method according to claim 5 comprises:

Form the right of the time migration value estimated according to tight adjacent signal frame;

For every pair of time migration value, determine a plurality of possible values of information; And

Select the possible value of information of frequency of occurrences maximum.

7. one kind is used a plurality of time migration values to obtain method about the indication of the information of transmission signals, described time migration value is the time migration value in the following system: in this system, PN sequence in the use PN sequence family comes the signal section of the frame of transmission signals is encoded, and use the second relevant PN sequence in the PN sequence family to come the signal section of the subsequent frame of this transmission signals is encoded, the one PN sequence and the 2nd PN sequence all comprise public PN section, the time offset of the public PN section between the signal section of described frame and the signal section of described subsequent frame by transmission signals in order to pass on information about transmission signals

Described method comprises:

Form the right of the time migration value estimated according to tight adjacent signal frame;

For every pair of time migration value, determine a plurality of possible values of information; And

Select the possible value of information of frequency of occurrences maximum.

8. method according to claim 7 comprises:

With the time migration value to being mapped to the zone in the scatter diagram; And

Determine a plurality of possible values of information according to described zone.

9. the equipment estimated of the time offset of the public PN section between the signal section of the subsequent frame that the second relevant PN sequence in the use PN sequence family is encoded in the signal section of the frame that a PN sequence of using in the transmission signals in the PN sequence family is encoded and this transmission signals, the one PN sequence and the 2nd PN sequence all comprise public PN section, in order to pass on the information about transmission signals, described equipment comprises described time offset by transmission signals:

The PN sequence characteristic that is used to carry out PN sequence family with corresponding to the first relevant device between the received signal of transmission signals;

Be used to analyze first result's who is correlated with device;

Be used to store the device of a part of received signal of selecting based on the first relevant result;

Be used to carry out the second relevant device between the received signal during the described subsequent frame and a part of received signal of being stored;

Be used for coming the device of side-play amount estimated time based on the second relevant correlation peak; And

Be used for the service time side-play amount and obtain device about the indication of the information of transmission signals.

10. equipment according to claim 9, wherein, described information is the signal frame index.

11. equipment according to claim 9 wherein, based on the time from the first relevant significant correlation peak value that obtains, is selected a part of received signal of being stored.

12. equipment according to claim 9 wherein, when determining from the first relevant significant correlation peak value that obtains, suppresses circulation and repeats.

13. equipment according to claim 9 wherein, uses a plurality of time migration values

13. equipment according to claim 9 wherein, uses a plurality of time migration values to obtain indication about the information of transmission signals.

14. equipment according to claim 13 comprises:

Be used to form the right device of the time migration value of estimating according to tight adjacent signal frame;

Be used for for every pair of time migration value, determine the device of a plurality of possible values of information; And

Be used to select the device of the possible value of information of frequency of occurrences maximum.

15. one kind is used a plurality of time migration values to obtain equipment about the indication of the information of transmission signals, described time migration value is the time migration value in the following system: in this system, use the PN sequence in the PN sequence family that the signal section of the frame of transmission signals is encoded, and use the second relevant PN sequence in the PN sequence family that the signal section of the subsequent frame of transmission signals is encoded, the one PN sequence and the 2nd PN sequence all comprise public PN section, the time offset of the public PN section between the signal section of described frame and the signal section of described subsequent frame by transmission signals in order to pass on information about transmission signals

Described equipment comprises:

Be used to form the right device of the time migration value of estimating according to tight adjacent signal frame;

Be used for for every pair of time migration value, determine the device of a plurality of possible values of information; And

Be used to select the device of the possible value of information of frequency of occurrences maximum.

16. equipment according to claim 16, wherein, the described device that is used for definite a plurality of possibility values of information comprises:

Be used for the time migration value to being mapped to the device in the zone in the scatter diagram; And

Be used for determining the device of a plurality of possible values of information according to described zone.

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