CN100373796C - Synchronous process for receiving data in short-range wireless network - Google Patents

Abstract

The present invention relates to a method for transmitting data in short-range wireless networks, which belongs to the technical field of wireless communication. Firstly, radio frequency signals transmitted by a sending end in a short-range wireless network are received; after down-conversion treatment is carried out, baseband sampling receiving signals are obtained; the signals on the positions of a front synchronous head in each sampling receiving signal within a time period are respectively multiplied in a centrosymmetric mode and are superposed; the maximum value in all superposition values is obtained; the position of a sampling receiving signal which corresponds to the maximum value is a conjugate phase point in the radio frequency signals; the signals on the position of the front synchronous head are detected from the baseband sampling receiving signals by a hypothesis detecting method according to the position of the conjugate phase point; a time synchronous value and a phase deviation estimating value are calculated. The method for transmitting data in short-range wireless networks provided by the present invention reduces calculating amount during the synchronization of time and frequency and makes a receiver have lower power consumption.

Description

Receive the data synchronization processing method in the short-range wireless networking

Technical field

The present invention relates to receive the data synchronization processing method in a kind of short-range wireless networking, relate in particular to reception and the time and the frequency synchronization method of data in the short-range wireless networking, belong to technical field of wireless communication.

Background technology

Mostly modern wireless communication is transmitted in packets, promptly only transmits a packet between the transceiver at every turn, all will carry out time and Frequency Synchronization between the transceiver before transfer of data begins each time.In the system based on spread spectrum, time synchronized should find the border of frequency expansion sequence, and in the sequence each element respective pulses optimum sampling constantly.And Frequency Synchronization is that the carrier frequency of receiving terminal and transmitting terminal is consistent, to eliminate the influence of frequency shift (FS) to the data demodulation.Therefore, Time and Frequency Synchronization is two very crucial in modern wireless network communication system problems.

In system based on spread spectrum, frequency expansion sequence generally all has good autocorrelation performance, by using the reference signal of known frequency expansion sequence as receiver this locality, conventional time synchronized can be abutted against collect mail number and the reference signal of receiver this locality between do that sliding is correlated with finishes.When frequency expansion sequence in the received signal and the alignment of the frequency expansion sequence in the reference signal, correlation can show a peak value, and in other cases, correlation approaches zero.But, when having bigger frequency deviation in the received signal, the slip correlation of received signal and receiver local reference signal can be subjected to very big influence, under some frequency deviation, even during the alignment of the frequency expansion sequence in frequency expansion sequence in the received signal and the reference signal, correlation also approaches zero.Occurring so big frequency deviation in the received signal mainly is because all use the crystal oscillator of low cost on the transmitter and receiver of short-range wireless networking, the deviation of this oscillator can reach ± 40ppm, for the system that is operated in the 900MHz frequency range, so big deviation can cause the frequency shift (FS) of 36KHz, if the cycle of a frequency expansion sequence is 16 μ s, mean that then the phase deviation that frequency deviation causes in this cycle has reached 1.15 π.

In order to use the relevant method deadline of sliding synchronous, need estimate the size of frequency deviation earlier and proofreaied and correct to received signal according to estimated value.The front and back difference is a kind of method commonly used in the frequency offset estimating, it utilizes the periodicity of preamble head place frequency expansion sequence in the received signal, frequency expansion sequence cycle of being separated by is carried out difference to former and later two sampled points, be the conjugation of a back dot product with previous point, to remove the phase place of frequency expansion sequence in the received signal itself, only stay the phase difference that frequency deviation causes, thereby estimate the value of frequency deviation.But, because the interval of phase estimation is-π～π, so this method can only estimate the frequency deviation of segment section among the frequency expansion sequence time T s.For the frequency deviation that exceeds this scope, can use U.S. Pat 5,303, the method that 257 (carrier wave in the DSSS communication system is proofreaied and correct, in April, 1994) propose is estimated.This method is estimated the value of frequency deviation by seeking received signal in the maximum of the energy at different frequency place, but the estimated value that it obtains is not accurate enough and amount of calculation is bigger.

Summary of the invention

The objective of the invention is to propose to receive the data synchronization method in a kind of short-range wireless networking, to solve the performance of Time and Frequency Synchronization under the big frequency deviation.In the delivery plan of IEEE802.15.4b standard code, the frequency expansion sequence that the cycle repeats is as the frame delimiter sequence.In method of reseptance, utilize the phase place symmetry characteristic of frequency expansion sequence, under the situation that correcting frequency offset does not disturb, at first obtain the estimated value of time synchronized, utilize the estimated value of time synchronized again, obtain the value of frequency offset estimating.

Receive the data synchronization processing method in the short-range wireless networking that the present invention proposes, comprise following each step:

(1) receives the radiofrequency signal that transmitting terminal sends in the short-range wireless networking, carry out obtaining the baseband sampling received signal after the down-converted, the signal at preamble head place in each the baseband sampling received signal in the time period is carried out the back stack of multiplying each other of center symmetry respectively obtain correlation, get the maximum in all correlations, be the position of the conjugate phase point of preamble head place signal in the baseband receiving signals with the corresponding abscissa of this maximum;

(2) according to the position of above-mentioned conjugate phase point, from above-mentioned baseband receiving signals, detect the signal of preamble head, and computing time synchronization value and skew estimated value.

In the said method, the signal at preamble head place in the sampling received signal is carried out the back stack of multiplying each other of center symmetry obtains the method for correlation, may further comprise the steps:

(1) taking out with any sampled point from the preamble head signal of baseband receiving signals is the sampled signal in former and later two frequency expansion sequence cycles at center;

(2) be the center with above-mentioned sampled point, above-mentioned two frequency expansion sequence sampled signals are carried out superposeing after the center symmetry multiplies each other;

(3) get long sampled point of Ts/2 time continuously, the center symmetry of repeating multiplies each other and superposes, and obtains the slip correlation of baseband receiving signals ${|R}_i|=|\underset{k=0}{\overset{L-1}{\mathrm{\Σ}}}{r}_{i-k}{\·r}_{i+k}|,$ Wherein Ts is a code-element period, r _iBe the sampling received signal, i≤Ts/2, k is long for the time between sampling received signal and the sampled point;

(4) with above-mentioned slip correlation in the corresponding abscissa of maximum, be the position of the conjugate phase point of preamble head place signal in the baseband receiving signals.

In the said method, utilize, from baseband receiving signals, detect the signal of preamble head, and computing time synchronization value and the method for skew estimated value, may further comprise the steps:

(1) is starting point with the conjugate phase point, from baseband receiving signals, takes out the sampled signal sequence in a spread spectrum cycle in the signal of preamble head, be designated as R1;

(2) be starting point behind above-mentioned conjugate phase point, to move long sampled point of Ts/2 time, from the signal of baseband receiving signals preamble head, take out the sampled signal sequence in a spread spectrum cycle, be designated as R2;

(3) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking is repeated, to move N after any one cycle starting point is original position, take out the local frequency expansion sequence in a spread spectrum cycle, be designated as L1, wherein N is the starting point of local band spectrum modulation complex sequences and the distance between the phase conjugation point;

(4) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking being repeated, is original position to move long sampled point of N+Ts/2 time after any one cycle starting point, takes out the local frequency expansion sequence in a spread spectrum cycle, is designated as L2;

(5) above-mentioned two sampled signal sequences are carried out the conjugation associative operation with above-mentioned two local frequency expansion sequences respectively, obtain two groups of thick skew estimated value sequences, be i.e. T1=R1 ' * L1, T2=R2 ' * L1;

With above-mentioned T1 sampled signal sequence R2 is compensated (6), obtains R2 that "=R2*T1 carries out associative operation with corresponding local frequency expansion sequence L2 again, " the * L2 that obtains correlation W1=R2;

With above-mentioned T2 sampled signal sequence R1 is compensated (7), obtains R1 that "=R1*T2 carries out associative operation with corresponding local frequency expansion sequence L2 again, " the * L2 that obtains correlation W2=R1;

(8) size of more above-mentioned two correlation W1 and W2, the position of the sampled signal sequence starting point corresponding with bigger correlation is conjugate phase point position, and the skew estimated value sequence corresponding with bigger correlation is the skew estimated value;

(9) move forward in above-mentioned conjugate phase point position between the starting point of local band spectrum modulation complex sequences and the phase conjugation point apart from N, be the time synchronized estimated value.

In the said method, from baseband receiving signals, detect the signal of preamble head, and computing time synchronization value and the method for skew estimated value, may further comprise the steps:

(1) is starting point with the conjugate phase point, from baseband receiving signals, takes out the sampled signal sequence in a spread spectrum cycle in the signal of preamble head, be designated as R1;

(2) be starting point behind above-mentioned conjugate phase point, to move long sampled point of Ts/2 time, from the signal of baseband receiving signals preamble head, take out the sampled signal sequence in a spread spectrum cycle, be designated as R2;

(3) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking is repeated, to move N after any one cycle starting point is original position, take out the local frequency expansion sequence in a spread spectrum cycle, be designated as L1, wherein N is the starting point of local band spectrum modulation complex sequences and the distance between the phase conjugation point;

(4) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking being repeated, is original position to move long sampled point of N+Ts/2 time after any one cycle starting point, takes out the local frequency expansion sequence in a spread spectrum cycle, is designated as L2;

(5) the conjugation correlation M=L1*L2 ' of local frequency expansion sequence L1 of calculating and L2, and the conjugation correlation of calculating sampling burst R1 and R2 is respectively K1=R1*R2 ', K2=R2*R1 ';

(6) above-mentioned conjugation correlation is carried out the conjugation associative operation, obtain correlation W1=K1*M ', W2=K2*M ', compare both sizes, the position of the sampled signal sequence starting point corresponding with bigger correlation is conjugate phase point position;

(7) sampled signal sequence corresponding with bigger correlation and local frequency expansion sequence L1 are carried out conjugate multiplication, obtain the skew estimated value;

(8) move forward in above-mentioned conjugate phase point position between the starting point of local band spectrum modulation complex sequences and the phase conjugation point apart from N, be the time synchronized estimated value.

The short-range wireless networking that the present invention proposes receives method of data synchronization, has the following advantages:

(1) the present invention has utilized the intrinsic phase conjugation centre symmetry matter that transmits, and has avoided the conjugate operation in the associative operation in the past, has reduced complexity and the amount of calculation calculated;

(2) the symmetrical correlation technique that relates in the inventive method has utilized the symmetrical correlation of signal, because relevant sequence is being slided simultaneously, so relevant main lobe can be narrower, improved the net synchronization capability under the multi-path environment, is not subjected to the influence of local frequency expansion sequence autocorrelation performance;

(3) algorithm synchronous and frequency offset estimating was independently realized by two steps in the inventive method, so time synchronization performance is not subjected to the frequency offset estimating Effect on Performance, frequency offset estimating also need not to carry out after time synchronized again, so just overcome the mutual coupled problem of time synchronized and frequency offset estimating in the synchronized algorithm in the past;

(4) symmetry of seeking the center symmetric points in the inventive method algorithm that matches has been avoided the influence of frequency deviation to correlation, can estimate the center symmetric position exactly under situation about not estimating with correcting frequency offset;

(5) received signal after utilizing synchronously in the inventive method is relevant with local frequency expansion sequence tries to achieve the skew estimation, has avoided asking the angle needed a large amount of computing of tabling look-up;

(6) symmetry only need the slide time span of Ts/2 of alignment symmetric points that multiplies each other among the present invention is general relevant 1/2nd of the one step process of seeking common ground that slides, and has therefore saved amount of calculation.

Description of drawings

Fig. 1 is the phase diagram of sampled signal.

Fig. 2 carries out the correlation figure that the center symmetry multiplies each other and afterwards superposes and obtain to the sampled signal of a spread spectrum period T s in the time.

Embodiment

Data receiving synchronous method in the short-range wireless networking that the present invention proposes, at first receive the radiofrequency signal that transmitting terminal sends in the short-range wireless networking, carry out obtaining the baseband sampling received signal after the down-converted, the signal at preamble head place in each the baseband sampling received signal in the time period is carried out the back stack of multiplying each other of center symmetry respectively obtain correlation, get the maximum in all correlations, be the position of the conjugate phase point of preamble head place signal in the baseband receiving signals with the corresponding abscissa of this maximum, position according to above-mentioned conjugate phase point, from above-mentioned baseband receiving signals, detect the signal of preamble head, and computing time synchronization value and skew estimated value.

In the above-mentioned data receive method, the signal at preamble head place in the sampling received signal is carried out the back stack of multiplying each other of center symmetry obtains the method for correlation, may further comprise the steps:

(1) taking out with any sampled point from the preamble head signal of baseband receiving signals is the sampled signal in former and later two frequency expansion sequence cycles at center;

(2) be the center with above-mentioned sampled point, above-mentioned two frequency expansion sequence sampled signals are carried out superposeing after the center symmetry multiplies each other;

(3) get long sampled point of Ts/2 time continuously, the center symmetry of repeating multiplies each other and superposes, and obtains the slip correlation of baseband receiving signals $\left|R_i\right|=|\underset{k=0}{\overset{L-1}{\mathrm{\Σ}}}{r}_{i-k}\·r_{i+k}|,$ Wherein Ts is a code-element period, and ri represents the received signal of sampling, i≤Ts/2, and k is long for the time between sampling received signal and the sampled point;

(4) with above-mentioned slip correlation in the corresponding abscissa of maximum, be the position of the conjugate phase point of preamble head place signal in the baseband receiving signals.

In the above-mentioned data receiving synchronous method, from baseband receiving signals, detect the signal of preamble head, and computing time synchronization value and the method for skew estimated value, may further comprise the steps:

(1) is starting point with the conjugate phase point, from baseband receiving signals, takes out the sampled signal sequence in a spread spectrum cycle in the signal of preamble head, be designated as R1;

(2) be starting point behind above-mentioned conjugate phase point, to move long sampled point of Ts/2 time, from the signal of baseband receiving signals preamble head, take out the sampled signal sequence in a spread spectrum cycle, be designated as R2;

(3) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking is repeated, to move N after any one cycle starting point is original position, take out the local frequency expansion sequence in a spread spectrum cycle, be designated as L1, wherein N is the starting point of local band spectrum modulation complex sequences and the distance between the phase conjugation point;

(4) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking being repeated, is original position to move long sampled point of N+Ts/2 time after any one cycle starting point, takes out the local frequency expansion sequence in a spread spectrum cycle, is designated as L2;

(5) above-mentioned two sampled signal sequences are carried out the conjugation associative operation with above-mentioned two local frequency expansion sequences respectively, obtain two groups of thick skew estimated value sequences, i.e. T1=R1 ' * L1; T2=R2 ' * L1;

With above-mentioned T1 sampled signal sequence R2 is compensated (6), obtains R2 that "=R2*T1 carries out associative operation with corresponding local frequency expansion sequence L2 again, " the * L2 that obtains correlation W1=R2;

With above-mentioned T2 sampled signal sequence R1 is compensated (7), obtains R1 that "=R1*T2 carries out associative operation with corresponding local frequency expansion sequence L2 again, " the * L2 that obtains correlation W2=R1;

(8) size of more above-mentioned two correlation W1 and W2, the position of the sampled signal sequence starting point corresponding with bigger correlation is conjugate phase point position, and the skew estimated value sequence corresponding with bigger correlation is the skew estimated value;

(9) move forward in above-mentioned conjugate phase point position between the starting point of local band spectrum modulation complex sequences and the phase conjugation point apart from N, be the time synchronized estimated value.

In the above-mentioned data receive method, from baseband receiving signals, detect the signal of preamble head, and computing time synchronization value and the method for skew estimated value, may further comprise the steps:

(1) is starting point with the conjugate phase point, from baseband receiving signals, takes out the sampled signal sequence in a spread spectrum cycle in the signal of preamble head, be designated as R1;

(2) be starting point behind above-mentioned conjugate phase point, to move long sampled point of Ts/2 time, from the signal of baseband receiving signals preamble head, take out the sampled signal sequence in a spread spectrum cycle, be designated as R2;

(3) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking is repeated, to move N after any one cycle starting point is original position, take out the local frequency expansion sequence in a spread spectrum cycle, be designated as L1, wherein N is the starting point of local band spectrum modulation complex sequences and the distance between the phase conjugation point;

(4) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking being repeated, is original position to move long sampled point of N+Ts/2 time after any one cycle starting point, takes out the local frequency expansion sequence in a spread spectrum cycle, is designated as L2;

(5) the conjugation correlation M=L1*L2 ' of local frequency expansion sequence L1 of calculating and L2, and the conjugation correlation of calculating sampling burst R1 and R2 is respectively K1=R1*R2 ', K2=R2*R1 ';

(6) above-mentioned conjugation correlation is carried out the conjugation associative operation, obtain correlation W1=K1*M ', W2=K2*M ', compare both sizes, the position of the sampled signal sequence starting point corresponding with bigger correlation is conjugate phase point position;

(7) sampled signal sequence corresponding with bigger correlation and local frequency expansion sequence L1 are carried out conjugate multiplication, obtain the skew estimated value;

(8) move forward in above-mentioned conjugate phase point position between the starting point of local band spectrum modulation complex sequences and the phase conjugation point apart from N, be the time synchronized estimated value.

Fig. 1 is the local phase diagram that sends preamble head place signal.The signal phase at preamble head place is a center conjugation symmetry with solid side point as we can see from the figure, remembers that this point is the conjugate phase point.Each Ts cycle memory is at the conjugate phase point of two fixed positions, and per two adjacent conjugate phase points are separated by half the Ts cycle.

In receiving course, at first receive the radiofrequency signal that transmitting terminal sends in the short-range wireless networking, carry out obtaining the baseband sampling received signal after the down-converted, the center symmetry multiplies each other and stack obtains a series of correlations by the sampling received signal at preamble head place is carried out then, judge the position of conjugate phase point again by the search maximum related value, judge sync bit and frequency offset estimating value.

Receive the data synchronization processing method in the short-range wireless networking of the present invention and at first will search out the conjugate phase point, be used for judging sync bit.

$\left|R_i\right|=|\underset{k=0}{\overset{L-1}{\mathrm{\Σ}}}{r}_{i-k}\·r_{i+k}|,$

Wherein, | R _i| the expression correlation, L represents the sampled point number in the spread spectrum period T s time, r _I+kRepresent the received signal that i+k is ordered.

Because the sampling received signal all can be subjected to the influence of frequency deviation when process transmits and receives the radio-frequency head of machine, the received signal of sampling this moment can be expressed as again:

r _i＝S _i·e ^j(2πiΔf)，

S wherein _iRepresent the local sequence of i point, Δ f represents frequency deviation.

Frequency deviation has not only changed the phase characteristic of sampling received signal, the more direct autocorrelation performance that changes a preamble received signal, thus cause traditional time synchronized algorithm can be subjected to the influence of frequency synchronization algorithm.And for the conjugate phase point, because sampling received signal is the phase conjugation symmetry before and after it, so the formula of top calculating correlation can further be expressed as again:

$\left|R_i\right|=|\underset{k=0}{\overset{L-1}{\mathrm{\Σ}}}{r}_{i-k}\·r_{i+k}|=|\underset{k=0}{\overset{L-1}{\mathrm{\Σ}}}{S}_{i-k}\·e^{j\left[2\mathrm{\π}(i-k)\mathrm{\Δf}\right]}\·S_{i+k}\·e^{j\left[2\mathrm{\π}(i+k)\mathrm{\Δf}\right]}|$

$=\left|e^{j\left(4\mathrm{\πi\Δf}\right)}\right|\·|\underset{k=0}{\overset{L-1}{\mathrm{\Σ}}}{S}_{i-k}\·S_{i+k}|$

$=|\underset{k=0}{\overset{L-1}{\mathrm{\Σ}}}{S}_{i-k}\·S_{i+k}|$

It is the influence that the judgement of conjugate phase point is not subjected to frequency deviation.

Try to achieve conjugate phase point back and just can judge sync bit by the conjugate phase point and the certain positional relationship of the starting point of local band spectrum modulation complex sequences, shown in solid side's point among Fig. 2, consider wherein under 2 times of over-sampling modes that conjugate phase point is N=4 with the position distance of the starting point of local band spectrum modulation complex sequences.But, therefore need the position of the starting point of the local band spectrum modulation complex sequences of judgement owing to two phase conjugation points are arranged in the cycle at Ts.

For the starting point of asking local band spectrum modulation complex sequences two kinds of implementation methods are arranged, a kind of is to utilize the particular location of phase conjugation point to judge the starting point of local band spectrum modulation complex sequences, and another kind is to utilize the relative position of phase conjugation point to judge the position of the starting point of local band spectrum modulation complex sequences.

The method of wherein judging phase conjugation point mainly comprises thick frequency offset estimating and the process relevant with local sequence, judges the position of phase conjugation point by comparing maximum related value again.Suppose that two phase conjugation point sync bits are respectively A point, B point in the Ts cycle.

Earlier hypothesis A point be correspondence the phase conjugation point of current estimation, with this phase conjugation point be starting point sampling received signal sequence R1 and the relevant influence that just can estimate frequency deviation of local sequence L1 that with the A point is starting point, T1=R1 ' * L1.Again this is estimated that compensate of frequency deviation is to conjugate phase point T backward again _s/ 2 is the sampling received signal sequence R2 of starting point, R2 "=R2*T1, with the receiving sequence behind the compensating for frequency offset with the B point be the initial relevant correlation that obtains of local sequence L2: W1=R2 " * L2.

In like manner, to conjugate phase point T backward again _s/ 2 for the sampling received signal sequence R2 of starting point carries out same operation, at first estimates frequency deviation T2=R2 ' * L1.Sampling received signal R1 after being compensated again "=R1*T2, relevant correlation: W2=R1 " the * L2 that obtains with local sequence L2.Obtain comparing size behind two correlations, the frequency offset estimating of bigger correlation correspondence is exactly the frequency offset estimating that needs, and the starting point of the sampling received signal sequence that is used for estimating is exactly a phase conjugation point A point.Because there is fixing alternate position spike phase conjugation point A point and time synchronized position, this alternate position spike is fallen in the phase conjugation point compensation of estimating, just can obtain the time synchronized value.

Judge the initial point position of local band spectrum modulation complex sequences for the relative position that utilizes phase conjugation point, its concrete implementation step is as described below.

Because two conjugate points in each code element are fixed, so can utilize the relative position information of two conjugate points directly to judge the particular location of current conjugate point.

Suppose that two phase conjugation point sync bits are respectively A point, B point in the Ts cycle.With the initial local sequence L1 of A point with respect to the B point be initial local sequence L2 ' phase deviation is, M=L1*L2 ', trying to achieve with the conjugate phase point more respectively is starting point, from baseband receiving signals, take out the sampled signal sequence R1 in a frequency expansion sequence cycle in the signal of preamble head, and with above-mentioned conjugate phase point T backward again _s/ 2 is starting point, takes out the relative phase relation of the sampled signal sequence R2 in a frequency expansion sequence cycle in the signal of preamble head from baseband receiving signals: K1=R1*R2 ', K2=R2*R1 '.

Then with relevant with M respectively correlation: W1=K1*M ', the W2=K2*M ' of obtaining of K1 and K2.The size of correlation W1 and W2 relatively, if K1 greater than K2, the starting point of the receiving sequence of sampling so R1 is exactly phase conjugation point A, otherwise the starting point of the receiving sequence R2 that samples is phase conjugation point A.The starting point of the local band spectrum modulation complex sequences in the phase conjugation point that same compensation is fallen to estimate and the alternate position spike that phase conjugation point A is ordered just can obtain the time synchronized value.

Claims (4)

1. receive the data synchronization processing method in a short-range wireless networking, it is characterized in that this method comprises following each step:

(1) receives the radiofrequency signal that transmitting terminal sends in the short-range wireless networking, carry out obtaining the baseband sampling received signal after the down-converted, the signal at preamble head place in each the baseband sampling received signal in the time period is carried out the back stack of multiplying each other of center symmetry respectively obtain correlation, get the maximum in all correlations, be the position of the conjugate phase point of preamble head place signal in the baseband receiving signals with the corresponding abscissa of this maximum;

(2) according to the position of above-mentioned conjugate phase point, from above-mentioned baseband receiving signals, detect the signal of preamble head, and computing time synchronization value and skew estimated value, detailed process comprises the steps:

(a) be starting point with the conjugate phase point, from baseband receiving signals, take out the sampled signal sequence in a spread spectrum cycle in the signal of preamble head, be designated as R1;

(b) be starting point behind above-mentioned conjugate phase point, to move long sampled point of Ts/2 time, from the signal of baseband receiving signals preamble head, take out the sampled signal sequence in a spread spectrum cycle, be designated as R2;

(c) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking is repeated, to move N after any one cycle starting point is original position, take out the local frequency expansion sequence in a spread spectrum cycle, be designated as L1, wherein N is the starting point of local band spectrum modulation complex sequences and the distance between the phase conjugation point;

(d) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking being repeated, is original position to move long sampled point of N+Ts/2 time after any one cycle starting point, takes out the local frequency expansion sequence in a spread spectrum cycle, is designated as L2;

(e) above-mentioned two sampled signal sequences are carried out the conjugation associative operation with above-mentioned two local frequency expansion sequences respectively, obtain two groups of thick skew estimated value sequences, be i.e. T1=R1 ' * L1, T2=R2 ' * L1;

(f) with above-mentioned T1 sampled signal sequence R2 is compensated, obtains R2 "=R2*T1, carry out associative operation with corresponding local frequency expansion sequence L2 again, obtain correlation w1=R2 " * L2;

(g) with above-mentioned T2 sampled signal sequence R1 is compensated, obtains R1 "=R1*T2, carry out associative operation with corresponding local frequency expansion sequence L2 again, obtain correlation W2=R1 " * L2;

(h) size of more above-mentioned two correlation w1 and W2, the position of the sampled signal sequence starting point corresponding with bigger correlation is conjugate phase point position, and the skew estimated value sequence corresponding with bigger correlation is the skew estimated value;

(i) move forward in above-mentioned conjugate phase point position between the starting point of local band spectrum modulation complex sequences and the phase conjugation point apart from N, be the time synchronized estimated value.

2. the method for claim 1 is characterized in that wherein said signal to preamble head place in the sampling received signal carries out the back stack of multiplying each other of center symmetry and obtains the method for correlation, may further comprise the steps:

(1) taking out with any sampled point from the preamble head signal of baseband receiving signals is the sampled signal in former and later two frequency expansion sequence cycles at center;

(2) be the center with above-mentioned sampled point, above-mentioned two frequency expansion sequence sampled signals are carried out superposeing after the center symmetry multiplies each other;

(3) get long sampled point of Ts/2 time continuously, the center symmetry of repeating multiplies each other and superposes, and obtains the slip correlation of baseband receiving signals $\left|R_i\right|=|\underset{k=0}{\overset{L-1}{\mathrm{\Σ}}}{r}_{i-k}\·r_{i+k}|,$ Wherein Ts is a code-element period, r _iBe the sampling received signal, i≤Ts/2, k is long for the time between sampling received signal and the sampled point:

(4) with above-mentioned slip correlation in the corresponding abscissa of maximum, be the position of the conjugate phase point of preamble head place signal in the baseband receiving signals.

3. receive the data synchronization processing method in a short-range wireless networking, it is characterized in that comprising following each step:

(1) receives the radiofrequency signal that transmitting terminal sends in the short-range wireless networking, carry out obtaining the baseband sampling received signal after the down-converted, the signal at preamble head place in each the baseband sampling received signal in the time period is carried out the back stack of multiplying each other of center symmetry respectively obtain correlation, get the maximum in all correlations, be the position of the conjugate phase point of preamble head place signal in the baseband receiving signals with the corresponding abscissa of this maximum;

(2) according to the position of above-mentioned conjugate phase point, from above-mentioned baseband receiving signals, detect the signal of preamble head, and computing time synchronization value and skew estimated value, detailed process comprises the steps:

(j) be starting point with the conjugate phase point, from baseband receiving signals, take out the sampled signal sequence in a spread spectrum cycle in the signal of preamble head, be designated as R1;

(k) be starting point behind above-mentioned conjugate phase point, to move long sampled point of Ts/2 time, from the signal of baseband receiving signals preamble head, take out the sampled signal sequence in a spread spectrum cycle, be designated as R2;

(1) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking is repeated, to move N after any one cycle starting point is original position, take out the local frequency expansion sequence in a spread spectrum cycle, be designated as L1, wherein N is the starting point of local band spectrum modulation complex sequences and the distance between the phase conjugation point;

(m) cycle of carrying out of local band spectrum modulation complex sequences in the short-range wireless networking being repeated, is original position to move long sampled point of N+Ts/2 time after any one cycle starting point, takes out the local frequency expansion sequence in a spread spectrum cycle, is designated as L2;

(n) the conjugation correlation M:I=L1*L2 ' of local frequency expansion sequence L1 of calculating and L2, and the conjugation correlation of calculating sampling burst R1 and R2 is respectively K1=R1*R2 ', K2=R2*R1 ';

(o) above-mentioned conjugation correlation is carried out the conjugation associative operation, obtain correlation w1=K1*M ', W2=K2*M ', compare both sizes, the position of the sampled signal sequence starting point corresponding with bigger correlation is conjugate phase point position;

(p) sampled signal sequence corresponding with bigger correlation and local frequency expansion sequence L1 are carried out conjugate multiplication, obtain the skew estimated value;

(q) move forward in above-mentioned conjugate phase point position between the starting point of local band spectrum modulation complex sequences and the phase conjugation point apart from N, be the time synchronized estimated value.

4. method as claimed in claim 3 is characterized in that wherein saidly the signal at preamble head place in the sampling received signal is carried out the back stack of multiplying each other of center symmetry obtaining the method for correlation, may further comprise the steps:

(1) taking out with any sampled point from the preamble head signal of baseband receiving signals is the sampled signal in former and later two frequency expansion sequence cycles at center;

(2) be the center with above-mentioned sampled point, above-mentioned two frequency expansion sequence sampled signals are carried out superposeing after the center symmetry multiplies each other;

(3) get long sampled point of Ts/2 time continuously, the center symmetry of repeating multiplies each other and superposes, and obtains the slip correlation of baseband receiving signals $\left|R_i\right|=|\underset{k=0}{\overset{L-1}{\mathrm{\Σ}}}{r}_{i-k}\·r_{i+k}|,$ Wherein Ts is a code-element period, r _iBe the sampling received signal, i≤Ts/2, k is long for the time between sampling received signal and the sampled point;

(4) with above-mentioned slip correlation in the corresponding abscissa of maximum, be the position of the conjugate phase point of preamble head place signal in the baseband receiving signals.

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