CN101626360B - Method and system for transmitting digital signal - Google Patents

Abstract

The invention relates to a method and a system for transmitting a digital signal. The method comprises the following steps: coding and modulating a signal to be transmitted to obtain a data block to be transmitted; alternately filling a PN complementary sequence in a PN complementary sequence pair between the adjacent data blocks to be used as a training sequence, a protective interval or a leader sequence, and framing; carrying out digital-to-analogue conversion and radio frequency modulation on a framed data frame and transmitting the data frame. The PN complementary sequence pair which has approximately ideal non-periodic autocorrelation and also retains differential properties of a PN sequence is filled into a transmitting frame of the digital signal in the method and the system and can effectively assist a receiver to carry out parameter estimation when resisting large-carrier wave frequency deviation.

Description

Digital signal transmission method and system

Technical field

The present invention relates to digital information transmission technical field, relate in particular to a kind of digital signal transmission method and system.

Background technology

In system of broadband wireless communication, data are auxiliary, and (data aided, method for parameter estimation DA) have advantages such as precision height, complexity are low.Being used for the time domain data that auxiliary parameter estimates is called training sequence, requires training sequence to have good automatic correlative property and cross correlation property usually.

(Pseudo Noise Sequence is a kind of training sequence commonly used PN) to pseudo random sequence, has the automatic correlative property and the cross correlation property of similar white Gaussian noise, and generates simply, is widely used in the communication system.It is the TDS-OFDM technology (Chinese patent that Tsing-Hua University proposes that a typical case of PN sequence uses; protection fill method at interval in the orthogonal FDM modulation system; patent No. ZL01124144.6), directly with the PN sequence as frame head, be used for carrying out receiver synchronously and channel estimating.Relative other OFDM technology, it is fast to have synchronizing speed, the estimated accuracy advantages of higher.

But automatic correlative property aperiodic of PN sequence is also imperfect, especially exists the bigger secondary lobe of power among the auto-correlation result aperiodic, has influenced the precision that receiver parameters is estimated to a certain extent.In fact, single sequence can not obtain desirable automatic correlative property aperiodic.M.Golay has proposed a kind of complementary series Golay complementary series (" Complementary series " in 1961, Information Theory, IRE Transactions on, 1961) it is autocorrelative and be two sequences of Kronecker-δ function that, the Golay complementary series is defined as aperiodic.On this basis, further obtain other character of Golay complementary series, all very simple such as maker and correlator, and also single Golay sequence has good power peak-to-average force ratio characteristic etc.

When training sequence be used for doing the initial synchronisation sign indicating number (Primary Synchronization Code, in the time of PSC), need system can to Chinese People's Anti-Japanese Military and Political College's carrier wave frequency deviation (Carrier Frequency Offset, CFO).People such as H.Meyr utilize the difference characteristic of PN sequence to carry out related operation, solved stationary problem (the Digital communication receivers:synchronization under the big carrier wave frequency deviation well, channel estimation and signal processing, New York:John Wiley ﹠amp; Sons, 1997).The Golay sequence does not then have similar character, therefore is difficult to the carrier wave frequency deviation to the Chinese People's Anti-Japanese Military and Political College, and application is restricted.

Summary of the invention

The purpose of this invention is to provide a kind of digital signal transmission method and system, fill autocorrelation aperiodic in the transmission frame of its digital signal with approximate ideal, the PN complementary series of difference character that has kept the PN sequence simultaneously is right, effectively auxiliary receiver carries out parameter Estimation in to Chinese People's Anti-Japanese Military and Political College's carrier wave frequency deviation, to remedy the deficiencies in the prior art.

For achieving the above object, the present invention adopts following technical scheme.

The digital signal processing method of one embodiment of the present invention, this method comprises the steps:

S1. treat that transmission signals is encoded, modulation treatment, obtain the data to be transmitted piece;

S2. the PN complementary series of alternately filling PN complementary series centering at described adjacent data interblock and carries out framing as training sequence, protection at interval or targeting sequencing;

S3. the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations, and send described Frame.

Wherein, described data block is basic single carrier data block, multicarrier data block, or is the broad sense data block, and the data block of described broad sense is one or more master data pieces and protection combination at interval thereof.

Wherein, described coding comprises Space Time Coding or space-frequency coding mode, with the data to be transmitted piece that obtains to transmit on double antenna.

Wherein, described PN complementary series is to being with nuclear PN sequence pn1, pn2 be elementary cell the PN complementary series to (a, b), and satisfy structural model:

a＝[pn1，pn2]，b＝[pn1，-pn2]。

Wherein, described PN complementary series is to being with nuclear PN sequence pn1, pn2 be elementary cell the PN complementary series to (a, b), and satisfy structural model:

a＝[pn1，-pn2(end：-1：1)]，b＝[pn2，pn1(end：-1：1)]

Wherein, pn1 (end:-1:1), pn2 (end:-1:1) represent the sequence after pn1, the pn2 backward respectively.

Wherein, described PN complementary series is to being that multi-stage cascade PN complementary series is to (a ⁽ⁿ⁾, b ⁽ⁿ⁾), the right basic complementary series of described multi-stage cascade PN complementary series is to being that the PN complementary series is to (a, b), described PN complementary series is to (a, b) with nuclear PN sequence pn1, pn2 is elementary cell, i.e. (a, b) be that the right first order cascade complementary series of described multi-stage cascade PN complementary series is right, and satisfy structural model:

a＝[pn1，pn2]，b＝[pn1，-pn2]，

(a ⁽ⁿ⁾, b ⁽ⁿ⁾) satisfy structural model:

a ⁽ⁿ⁾＝[a ^(n-1)，b ^(n-1)]，b ⁽ⁿ⁾＝[a ^(n-1)，-b ^(n-1)]。

Wherein, described PN complementary series is to being that multi-stage cascade PN complementary series is to (a ⁽ⁿ⁾, b ⁽ⁿ⁾), the right basic complementary series of described multi-stage cascade PN complementary series is to being that the PN complementary series is to (a, b), described PN complementary series is to (a, b) with nuclear PN sequence pn1, pn2 is elementary cell, i.e. (a, b) be that the right first order cascade complementary series of described multi-stage cascade PN complementary series is right, and satisfy structural model:

A=[pn1 ,-pn2 (end:-1:1)], b=[pn2 ,-pn1 (end:-1:1)] and, (a ⁽ⁿ⁾, b ⁽ⁿ⁾) satisfy structural model:

a ⁽ⁿ⁾＝[a ^(n-1)，-b ^(n-1)(end：-1：1)]，b ⁽ⁿ⁾＝[b ^(n-1)，a ^(n-1)(end：-1：1)]，

Wherein, pn1 (end:-1:1), pn2 (end:-1:1) represent the sequence after pn1, the pn2 backward respectively.

Wherein, described PN sequence comprises that length is 2 ⁿ-1 M sequence also comprises the blocking or the time domain binary sequence of random length of cyclic extensions, M sequence of M sequence.

Another execution mode of the present invention also provides a kind of transmission system of digital signal, and this system comprises: signal processing module, be used to treat that transmission signals is encoded, modulation treatment, and obtain the data to be transmitted piece; Framing module, the PN complementary series that is used for alternately filling PN complementary series centering at the adjacent data interblock and are carried out framing as training sequence, protection at interval or targeting sequencing; Back end processing module is used for the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations, and sends described Frame.

Another execution mode of the present invention provides a kind of above-mentioned digital signal transmission system receiver synchronous cross-correlator, this correlator comprises a plurality of delay structures and two sub-correlators, the coefficient of described sub-correlator is nuclear PN sequence pn1, pn2, described nuclear PN sequence pn1, pn2 are that the PN complementary series is to (a, basic sequence b)

Another execution mode of the present invention provides a kind of above-mentioned digital signal transmission system receiver synchronous differential correlator, this differential correlator comprises a plurality of delay structures and two sub-correlators, and the coefficient of described sub-correlator is the circulation difference of nuclear PN sequence pn1, pn2

Described nuclear PN sequence pn1, pn2 are that the PN complementary series is to (a, basic sequence b).

Description of drawings

Fig. 1 is the digital signal transmission method flow chart according to one embodiment of the present invention;

Fig. 2 (a) is auto-correlation result schematic diagram aperiodic of single PN sequence;

Fig. 2 (b) is complementary aperiodic of the auto-correlation result schematic diagram of basic PN complementary series;

Fig. 2 (c) is complementary aperiodic of the auto-correlation result schematic diagram of Golay complementary series;

Fig. 3 (a) is 320 PN complementary series for length to complementary aperiodic of the auto-correlation result schematic diagram of structural model 1;

Fig. 3 (b) is 320 PN complementary series for length to complementary aperiodic of the auto-correlation result schematic diagram of structural model 2;

Fig. 4 (a) is 420 PN complementary series for length to complementary aperiodic of the auto-correlation result schematic diagram of structural model 1;

Fig. 4 (b) is 420 PN complementary series for length to complementary aperiodic of the auto-correlation result schematic diagram of structural model 2;

Fig. 5 (a) be the basic PN sequence complementary aperiodic the auto-correlation result and aperiodic the cross correlation results schematic diagram;

Fig. 5 (b) be second level cascade PN sequence complementary aperiodic the auto-correlation result and aperiodic the cross correlation results schematic diagram;

Fig. 5 (c) be third level cascade PN sequence complementary aperiodic the auto-correlation result and aperiodic the cross correlation results schematic diagram;

Relevant (D=1) result schematic diagram of the difference of Fig. 6 (a) basic PN sequence under big carrier wave frequency deviation;

Relevant (D=1) result schematic diagram of the difference of Fig. 6 (b) PN complementary series under big carrier wave frequency deviation;

Relevant (D=1) result schematic diagram of the difference of Fig. 6 (c) Golay complementary series under big carrier wave frequency deviation;

Fig. 7 is the digital signal transmission system block diagram according to one embodiment of the present invention;

Fig. 8 fills the transferring data frames structural representation of protection digital signal transmission method at interval for the PN complementary series that utilizes according to one embodiment of the present invention among the embodiment 1;

Fig. 9 is for utilizing the transferring data frames structural representation of PN complementary series as the digital signal transmission method of targeting sequencing according to one embodiment of the present invention among the embodiment 2;

Figure 10 among the embodiment 3,4 according to the transferring data frames structural representation of the digital signal transmission method of the dual-antenna system that is applied to the space-time/space-frequency coding of one embodiment of the present invention;

Figure 11 is according to the synchronous cross-correlator structural representation of the digital signal transmission system receiver of one embodiment of the present invention;

Figure 12 is according to the synchronous differential correlator structural representation of the digital signal transmission system receiver of one embodiment of the present invention.

A kind of optimum PN complementary series searching method flow chart that Figure 13 proposes for the present invention.

Embodiment

Digital signal transmission method and system thereof that the present invention proposes are described as follows in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, the digital signal transmission method of present embodiment comprises the steps:

S1. treat that transmission signals is encoded, modulation treatment, obtain the data to be transmitted piece;

S2. the PN complementary series of alternately filling PN complementary series centering at the adjacent data interblock is as training sequence, and framing;

S3. the Frame behind the framing is carried out processing such as digital-to-analogue conversion, rf modulations, and send this Frame.

Wherein, among the step S1, data block can be basic single carrier data block or multicarrier data block, also can be the data block of broad sense, promptly one or more master data pieces and protection combination at interval thereof.

Among the step S2, the PN complementary series is to being with nuclear PN sequence pn1, pn2 be elementary cell the PN complementary series to (a, b), and satisfy pattern:

Pattern one: a=[pn1, pn2], b=[pn1 ,-pn2], or

Pattern two: a=[pn1 ,-pn2 (end:-1:1)], b=[pn2, pn1 (end:-1:1)]

Pn1, pn2 be value 1, the binary sequence of 1}, [pn1, pn2] expression is with the sequence of sequence pn1, pn2 direct splicing Cheng Xin, pn1 (end:-1:1), pn2 (end:-1:1) represent the sequence after pn1, the pn2 backward respectively.

Wherein, the applied PN sequence of the present invention comprises the PN sequence of narrow sense, and promptly length is 2 ⁿ-1 M sequence also comprises the PN sequence of broad sense, and promptly the cyclic extensions of M sequence, M sequence blocks or the time domain binary sequence of random length.

Further, the PN complementary series is to also can be multi-stage cascade PN complementary series to (a ⁽ⁿ⁾, b ⁽ⁿ⁾), the right basic complementary series of multi-stage cascade PN complementary series is to being with nuclear PN sequence pn1, pn2 is that the PN complementary series of elementary cell is to (a, b), promptly (a be that the right first order cascade complementary series of multi-stage cascade PN complementary series is right b), note work (a ⁽¹⁾, b ⁽¹⁾), multi-stage cascade PN complementary series is to also satisfying two kinds of structural models, and each grade structure can be chosen any one kind of them from following two kinds of patterns:

Pattern one:

a ⁽ⁿ⁾＝[a ^(n-1)，b ^(n-1)]，b ⁽ⁿ⁾＝[a ^(n-1)，-b ^(n-1)]

Especially, a ⁽¹⁾=[pn1, pn2], b ⁽¹⁾=[pn1 ,-pn2]

Pattern two:

a ⁽ⁿ⁾＝[a ^(n-1)，-b ^(n-1)(end：-1：1)]，b ⁽ⁿ⁾＝[b ^(n-1)，a ^(n-1)(end：-1：1)]

Especially, a ⁽¹⁾=[pn1 ,-pn2 (end:-1:1)], b ⁽¹⁾=[pn2, pn1 (end:-1:1)]

By the aperiodic auto-correlation and difference relevant calculating right, analyze PN complementary series that the present invention proposes to as the right advantage of the training sequence in the native system to the PN complementary series.

Sequence a, auto-correlation aperiodic of b is respectively:

$R_{\mathrm{aa}}\left(k\right)=\underset{j}{\mathrm{\Σ}}a\left(j\right)a^{*}(j+k)$

, * represents to get conjugation.

$R_{\mathrm{bb}}\left(k\right)=\underset{j}{\mathrm{\Σ}}b\left(j\right)b^{*}(j+k)$

Definition PN complementary series to (a, complementary aperiodic of auto-correlation b) is:

R _c(k)＝R _aa(k)+R _bb(k)

R _c(k) can obtain a relevant peaks preferably at the k=0 place, secondary lobe is then because the complementary part that occurs disappears mutually, thereby the single relatively PN sequence of secondary lobe power has clear improvement.

With length is that 63 PN sequence is an example, gets one group of pn1, pn2, by structural model 1 obtain (a, b), a, b length is 126, corresponding with it, choosing single PN sequence length is 255, right length is 128 to choose the Golay complementary series.Three kinds of sequences aperiodic the auto-correlation result shown in Fig. 2 (a)-Fig. 2 (c), the aperiodic of single PN sequence, secondary lobe power was bigger among the auto-correlation result; And the secondary lobe power of PN complementary series is compared single PN sequence and is reduced greatly, and long zero correlation zone occurs; The Golay complementary series then has desirable auto-correlation result aperiodic, and secondary lobe power is zero.

Be that 160 broad sense m sequence is as the nuclear sequence with length, broad sense m sequence is that length is 128 the m sequence and the combination of Cyclic Prefix thereof, it is right to constitute length and be 320 PN complementary series, structural model 1 and structural model 2 complementary aperiodic the auto-correlation result respectively shown in Fig. 3 (a) and Fig. 3 (b).

Be 210 broad sense m sequence with length as and sequence, broad sense m sequence is that length is blocking of 255 m sequence, it is right to constitute length and be 420 PN complementary series, structural model 1 and structural model 2 complementary aperiodic the auto-correlation result respectively shown in Fig. 4 (a) and Fig. 4 (b).

Equally, right complementary aperiodic of the auto-correlation of definition cascade PN complementary series is:

$R_{a^{\left(n\right)}{a}^{\left(n\right)}}\left(k\right)=\underset{j}{\mathrm{\Σ}}{a}^{\left(n\right)}\left(j\right){\left(a^{\left(n\right)}(j+k)\right)}^{*}$

$R_{b^{\left(n\right)}{b}^{\left(n\right)}}\left(k\right)=\underset{j}{\mathrm{\Σ}}{b}^{\left(n\right)}\left(j\right){\left(b^{\left(n\right)}(j+k)\right)}^{*}$

$R_c\left(k\right)=R_{a^{\left(n\right)}{a}^{\left(n\right)}}\left(k\right)+R_{b^{\left(n\right)}{b}^{\left(n\right)}}\left(k\right)$

The definition complementary series between cross-correlation aperiodic be:

$R_{a^{\left(n\right)}{b}^{\left(n\right)}}\left(k\right)=\underset{j}{\mathrm{\Σ}}{a}^{\left(n\right)}\left(j\right){\left(b^{\left(n\right)}(j+k)\right)}^{*}$

Cascade PN complementary series has still kept desirable automatic correlative property aperiodic of part, is 63 pn1 with above-mentioned length, and pn2 is an example, and cascade obtains (a successively ⁽¹⁾, b ⁽¹⁾), (a ⁽²⁾, b ⁽²⁾), (a ⁽³⁾, b ⁽³⁾), multi-stage cascade PN complementary series complementary aperiodic the auto-correlation result and cross correlation results shown in Fig. 5 (a)-Fig. 5 (c).For relatively convenient, all correlated results are through autocorrelative correlation peak normalization aperiodic.

Automatic correlative property aperiodic meeting severe exacerbation under big carrier wave frequency deviation of sequence.For to Chinese People's Anti-Japanese Military and Political College's carrier wave frequency deviation, good characteristic of PN sequence is that sequence self is still the PN sequence after dividing through Cycle Difference, establishes sequence c (n) | _N=0 ^N-1For length is the PN sequence of N, to get difference and be spaced apart D, c (n) self Cycle Difference branch obtains

$z\left(n\right)=\left\{\begin{array}{cc}c\left(n\right)\·c^{*}(n+N-D),& n=\mathrm{0,1},...,D-1\\ c\left(n\right)\·c^{*}(n-D),& n=D,2,...,N-1\end{array}\right.$

Wherein, z (n) remains a PN sequence.Suppose to send sequence c (n), only consider the influence of carrier wave frequency deviation, receiving sequence $r\left(n\right)=c\left(n\right)\·e^{-j\·n\·{\mathrm{\ω}}_c},$ ω _cBe normalization carrier wave frequency deviation value.R (n) and self difference obtain

$z_r\left(n\right)=r\left(n\right)\·r^{*}(n-D)$

$=c\left(n\right)\·e^{-\mathrm{jn}{\mathrm{\ω}}_c}\·c^{*}(n+D)\·e^{j(n-D){\mathrm{\ω}}_c}$

$=z\left(n\right)\·e^{-j\·D\·{\mathrm{\ω}}_c},n=D,...,N-1$

Z (n) and z _r(n) carry out related calculation

$R\left(k\right)=\underset{n}{\mathrm{\Σ}}z\left(n\right)\·z_r^{*}(n+k)\≈\underset{n}{\mathrm{\Σ}}z\left(n\right)\·z^{*}(n+k)\·e^{j\·D\·{\mathrm{\ω}}_c}$

$\≈R_z\left(k\right)\·e^{j\·D\·{\mathrm{\ω}}_c}$

|R(k)|≈|R _z(k)|

Because z (n) also is the PN sequence, so auto-correlation R aperiodic of z (n) _z(k) also have good relevant peaks, the phase angle of R (k) has carried carrier wave frequency deviation information simultaneously, can be used to do the rough estimate of carrier wave frequency deviation.Because circulate difference can not appear in the computing cross-correlation actual aperiodic, so correlated results | R (k) | just be approximately equal to | R _z(k) |, when D was big, deviation can increase.

The PN complementary series of the PN complementary series centering that the present invention proposes has kept the difference characteristic of PN sequence.Fig. 6 (a)-Fig. 6 (c) has provided single PN sequence, PN complementary series, Golay complementary series at the normalization carrier wave frequency deviation ${\mathrm{\ω}}_c=\frac{2}{13}\mathrm{\π}$ The time difference is divided the result of relevant (D=1).Because the PN complementary series is right through complementary series just approximate after the difference, therefore the correlated results that obtains worsens to some extent, has more powerful secondary lobe; And Golay complementary series difference relevant nature is very poor, is difficult to the carrier wave frequency deviation to the Chinese People's Anti-Japanese Military and Political College.

As shown in Figure 7, the invention allows for a kind of digital signal transmission system, this system comprises: signal processing module, be used to treat that transmission signals is encoded, modulation treatment, and obtain the data to be transmitted piece; The framing module, the PN complementary series that is used for alternately filling PN complementary series centering at the adjacent data interblock is as training sequence, and framing; Back end processing module is used for the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations, and sends described Frame.

Embodiment 1

According to one embodiment of the present invention, present embodiment proposes a kind of PN complementary series that utilizes and fills protection digital signal transmission method and system thereof at interval, and the method comprising the steps of:

S101. treat that transmission signals is encoded, constellation mapping, single-carrier modulated or OFDM modulation, obtain single carrier data block waiting for transmission or OFDM data block;

S102. the PN complementary series of alternately filling PN complementary series centering at the adjacent data interblock and carries out framing as protection at interval;

S103. the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations etc., and Frame is sent.

Wherein, the structure of Frame as shown in Figure 8, the PN complementary series is (protection that a, the b) a in, b alternately fill adjacent data blocks at interval, simultaneously as training sequence.

The digital signal transmission system that utilizes the PN complementary series to fill the protection interval of the transmission method correspondence of above-mentioned digital signal comprises: signal processing module, be used to treat that transmission signals is encoded, constellation mapping, single-carrier modulated or OFDM modulation, obtain single carrier data block waiting for transmission or OFDM data block; The framing module is used for alternately filling the PN complementary series of PN complementary series centering as the protection interval at the adjacent data interblock; Back end processing module is used for the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations etc., and Frame is sent.

Embodiment 2

According to one embodiment of the present invention, present embodiment proposes a kind of digital signal transmission method and system thereof that utilizes the PN complementary series as targeting sequencing, and the method comprising the steps of:

S201. treat that transmission signals is encoded, constellation mapping, OFDM modulation, insert Cyclic Prefix (CP, cyclic prefix) at interval, obtain CP-OFDM data block waiting for transmission as protection;

S202. between one or more CP-OFDM data block, alternately insert the targeting sequencing of the PN complementary series of PN complementary series centering as Frame;

S203. the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations etc., and Frame is sent.

Wherein, the structure of Frame as shown in Figure 9, (a b) alternately inserts between one or more CP-OFDM data blocks, as the targeting sequencing of Frame the PN complementary series.

The above-mentioned PN of utilization complementary series comprises as the transmission method system of the digital signal of targeting sequencing: signal processing module, and be used to treat that transmission signals is encoded, constellation mapping, OFDM modulation, insert Cyclic Prefix, obtain CP-OFDM data block waiting for transmission; The framing module is used for alternately inserting the PN complementary series of PN complementary series centering as targeting sequencing between one or more CP-OFDM data block; Back end processing module is used for the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations etc., and Frame is sent.

Embodiment 3

According to one embodiment of the present invention, present embodiment proposes a kind of digital signal transmission method that is applied to the dual-antenna system of Space Time Coding, and the method comprising the steps of:

S301. treat that transmission signals is encoded, modulation treatment, carry out Space Time Coding again, obtain the data to be transmitted piece of antenna 1 and antenna 2 respectively;

S302. insert the PN complementary series of PN complementary series centering of structural model 1 respectively as training sequence at the data to be transmitted interblock of antenna 1 and antenna 2;

S303. the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations etc., the two paths of data frame is sent by double antenna.

Wherein, among the step S301, data block can be basic single carrier data block or OFDM data block, also can be the data block of broad sense, promptly one or more master data pieces and protection combination at interval thereof.

Wherein, among the step S302, the training sequence that antenna 1 and antenna 2 synchronizations send is respectively the PN complementary series to (a, b) a in and b; In the Frame of same antenna transmission, PN complementary series centering a, b alternately insert between the data block, and data frame structure as shown in Figure 9.

With reference to the Walsh encoding relation, if the Walsh encoding relation is satisfied in the training sequence discrete Fourier transform territory that antenna 1 and antenna 2 adjacent moment send, promptly

$S=\left[\begin{array}{cc}{\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">S</figure-callout>}}_1,& S_2\\ {\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">S</figure-callout>}}_1,& -{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">S</figure-callout>}}_2\end{array}\right]$

Then the time domain expression formula of training sequence satisfies

$s=\left[\begin{array}{cc}{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">s</figure-callout>}}_1,& s_2\\ {\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">s</figure-callout>}}_1,& -{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\end{array}\right]$

If s ₁, s ₂Be respectively nuclear PN sequence pn1, pn2 that the present invention proposes, then have

$s=\left[\begin{array}{cc}\mathrm{<figure-callout\; id="1"\; label="pn"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">pn</figure-callout>}1,& \mathrm{<figure-callout\; id="2"\; label="pn"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">pn</figure-callout>}2\\ \mathrm{<figure-callout\; id="2"\; label="pn"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">pn</figure-callout>}2,& -\mathrm{<figure-callout\; id="1"\; label="pn"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">pn</figure-callout>}1\end{array}\right]=\left[\begin{array}{c}a\\ b\end{array}\right]$

If s ₁, s ₂Be respectively the PN complementary series a of 1 time n level cascade of pattern of the present invention's proposition ⁽ⁿ⁾, b ⁽ⁿ⁾, then have

$s=\left[\begin{array}{cc}{a}^{\left(n\right)},& b^{\left(n\right)}\\ b^{\left(n\right)},& -a^{\left(n\right)}\end{array}\right]=\left[\begin{array}{c}{a}^{(n+1)}\\ b^{(n+1)}\end{array}\right]$

As seen, under the Walsh encoding relation, two antennas of synchronization are the PN complementary series of sending mode 1 respectively, and both have good automatic correlative property and cross correlation property, are applicable to the double-antenna transmit diversity system.

The double antenna digital signal transmission system of present embodiment comprises: signal processing module, be used to treat that transmission signals is encoded, modulation treatment, obtain the data to be transmitted piece, when wherein coded system comprises sky or space-frequency coding, to obtain the data to be transmitted piece of transmission on antenna 1,2; The framing module is used for alternately inserting the PN complementary series of PN complementary series centering as training sequence at the adjacent data interblock; Back end processing module is used for the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations etc., and the two paths of data frame is sent by double antenna.

Embodiment 4

According to one embodiment of the present invention, present embodiment provides a kind of digital signal transmission method that is applied to the dual-antenna system of space-frequency coding, and the method comprising the steps of:

S401. treat that transmission signals is encoded, modulation treatment, carry out space-frequency coding again, obtain the data to be transmitted piece of antenna 1 and antenna 2 respectively;

S402. insert the PN complementary series of PN complementary series centering of structural model 2 respectively as training sequence at the data to be transmitted interblock of antenna 1 and antenna 2;

S403. the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations etc., the two paths of data frame is sent by double antenna.

Wherein, among the step S401, data block can be basic single carrier data block or multicarrier data block, also can be the data block of broad sense, promptly one or more master data pieces and protection combination at interval thereof.

Wherein, among the step S302, the training sequence that antenna 1 and antenna 2 synchronizations send is respectively the PN complementary series to (a, a b) and b; In the Frame of same antenna transmission, PN complementary series centering a, b alternately insert between the data block, and data frame structure as shown in figure 10.

With reference to the Alamouti encoding relation, if the Alamouti encoding relation is satisfied in the training sequence discrete Fourier transform territory that antenna 1 and antenna 2 adjacent moment send, promptly

$S=\left[\begin{array}{cc}{\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">S</figure-callout>}}_1,& -{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">S</figure-callout>}}_2^{*}\\ {\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">S</figure-callout>}}_2,& {\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">S</figure-callout>}}_1^{*}\end{array}\right]$

Then the time domain expression formula of training sequence satisfies

$s=\left[\begin{array}{cc}{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">s</figure-callout>}}_1,& -s_2(\mathrm{end}:-1:1)\\ {\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">s</figure-callout>}}_2,& s_1(\mathrm{end}:-1:1)\end{array}\right]$

If s ₁, s ₂Be respectively nuclear PN sequence pn1, pn2 that the present invention proposes, then have

$s=\left[\begin{array}{cc}\mathrm{<figure-callout\; id="1"\; label="pn"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">pn</figure-callout>}1,& -\mathrm{pn}2(\mathrm{end}:-1:1)\\ \mathrm{<figure-callout\; id="2"\; label="pn"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">pn</figure-callout>}2,& \mathrm{pn}1(\mathrm{end}:-1:1)\end{array}\right]=\left[\begin{array}{c}a\\ b\end{array}\right]$

If s ₁, s ₂Be respectively the PN complementary series a of the n level cascade under the pattern 2 that the present invention proposes ⁽ⁿ⁾, b ⁽ⁿ⁾, then have

$s=\left[\begin{array}{cc}{a}^{\left(n\right)},& {-b}^{\left(n\right)}(\mathrm{end}:-1:1)\\ b^{\left(n\right)},& a^{\left(n\right)}(\mathrm{end}:-1:1)\end{array}\right]=\left[\begin{array}{c}{a}^{(n+1)}\\ b^{(n+1)}\end{array}\right]$

As seen, under the Alamouti encoding relation, the PN complementary series under two antennas difference of synchronization sending mode 2, both have good automatic correlative property and cross correlation property, are applicable to the dual-antenna diversity system.

The double antenna digital signal transmission system of present embodiment is identical with system among the embodiment 3.

Embodiment 5

As shown in figure 11, be the synchronous cross-correlator structure of the digital signal transmission system receiver of one embodiment of the present invention, comprise that mainly coefficient is sub-correlator and some delay unit of nuclear PN sequence pn1, pn2.Single relatively PN sequence, the correlator complexity reduces half.

Suppose to send the sequence frame structure as shown in Figure 8, receiving sequence r (n) through the cross correlation value that cross-correlator obtains is:

R _C(k)＝R _r，a(k)+R _r，b(k+N+L)

When k slide into Frame in original position when alignment of a, above-mentioned cross correlation value is:

R _C(k)＝R _aa(k)+R _bb(k)

With the PN complementary series of first order cascade to (a b) is example, sequence a, auto-correlation aperiodic of b is respectively

$R_{a,a}\left(k\right)=\underset{j=0}{\overset{N-1}{\mathrm{\&Sigma;}}}a\left(j\right)\&CenterDot;a^{*}(j+k)$

$=\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\mathrm{pn}1\left(j\right)\&CenterDot;a^{*}(j+k)+\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\mathrm{pn}2\left(j\right)\&CenterDot;a^{*}(\frac{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">N</figure-callout>}}{2}+j+k)$

$R_{b,b}\left(k\right)=\underset{j=0}{\overset{N-1}{\mathrm{\&Sigma;}}}b\left(j\right)\&CenterDot;b^{*}(j+k)$

$=\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\mathrm{pn}1\left(j\right)\&CenterDot;b^{*}(j+k)-\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\mathrm{pn}2\left(j\right)\&CenterDot;b^{*}(\frac{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">N</figure-callout>}}{2}+j+k)$

Remember complementary correlation

$R_c\left(k\right)=R_{a,a}\left(k\right)+R_{b,b}\left(k\right)$

$=\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\mathrm{pn}1\left(j\right)\&CenterDot;a^{*}(j+k)+\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\mathrm{pn}2\left(j\right)\&CenterDot;a^{*}(\frac{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">N</figure-callout>}}{2}+j+k)+$

$\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\mathrm{pn}1\left(j\right)\&CenterDot;b^{*}(j+k)-\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\mathrm{pn}2\left(j\right)\&CenterDot;b^{*}(\frac{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">N</figure-callout>}}{2}+j+k)$

$=\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\mathrm{pn}1\left(j\right)\&CenterDot;{[a(j+k)+b(j+k)]}^{*}+$

$\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\mathrm{pn}2\left(j\right)\&CenterDot;{[a(j+k+\frac{N}{2})-b(j+k+\frac{N}{2})]}^{*}$

By above-mentioned derivation as can be seen, carry out related operation at receiving terminal, only needing with nuclear PN sequence pn1, pn2 is the correlator of coefficient.Length is N ₁=2 ⁿ-1 PN sequence correlator complexity is O (N ₁), corresponding with it, nuclear PN sequence length is N ₂=2 ^N-1Right complementary aperiodic of the related operation complexity of-1 PN complementary series is O (N ₂)～O (N ₁/ 2); Length is N ₃=2 ⁿGolay sequence correlator complexity be O (log ₂N ₃)～O (log ₂N ₁).As seen, the correlator complexity of PN complementary series is approximately 1/2 of single PN sequence, and the correlator complexity of Golay complementary series then is logarithm and descends.

Similarly, complementary aperiodic of the related operation complexity of multi-stage cascade PN complementary series reduces at double with respect to single PN sequence.

Embodiment 6

As shown in figure 12, be the synchronous differential correlator structure of digital signal transmission system receiver according to the present embodiment of one embodiment of the present invention, different with common cross-correlator is that receiving sequence r (n) at first obtains through the calculus of differences that is spaced apart D

Simultaneously, the coefficient of inner two sub-correlators is the circulation difference of pn1, pn2

Suppose to send the sequence frame structure as shown in Figure 8, then receiving sequence r (n) through the difference cross correlation value that this difference cross-correlator obtains is:

$R_d\left(k\right)=R_{\tilde{r}\tilde{a}}\left(k\right)+R_{\tilde{r}\tilde{b}}(k+N+L)$

When k slide into Frame in original position when alignment of a, above-mentioned difference correlation is approximately:

$R_d\left(k\right)=R_{\tilde{a}\tilde{a}}\left(k\right)+R_{\tilde{b}\tilde{b}}\left(k\right)$

The difference related algorithm is as follows:

$\tilde{a}\left(n\right)=a\left(n\right)\&CenterDot;a^{*}(n-D)$

$=\left\{\begin{array}{cc}\mathrm{pn}1\left(n\right)\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="pn"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">pn</figure-callout>}2}^{*}(n+N/2-D),& n=\mathrm{0,1},...D-1\\ \mathrm{pn}1\left(n\right)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="pn"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">pn</figure-callout>}1}^{*}(n-D),& n=D,2,...,N/2-1\\ {\mathrm{<figure-callout\; id="2"\; label="pn"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">pn</figure-callout>}2}^{*}(n-N/2)\mathrm{pn}1(n-D),& n=N/2,...,N/2+D-1\\ \mathrm{pn}2(n-N/2)\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="pn"\; filenames="H2009100901897E00072.png"\; state="\{\{state\}\}">pn</figure-callout>}2}^{*}(n-N/2-D),& n=N/2+D,...,N-1\end{array}\right.$

Equally, structure $\tilde{b}\left(n\right)=b\left(n\right)\&CenterDot;b^{*}(n-D).$

Order

$\tilde{p}n1\left(n\right)=\left\{\begin{array}{cc}\mathrm{pn}1\left(n\right){\mathrm{pn}1}^{*}(n+N/2-D),& n=\mathrm{0,1},...,D-1\\ \mathrm{pn}1\left(n\right){\mathrm{pn}1}^{*}(n+D),& n=D,2,...,N/2-1\end{array}\right.$

$\tilde{p}n2\left(n\right)=\left\{\begin{array}{cc}\mathrm{pn}2\left(n\right){\mathrm{pn}2}^{*}(n+N/2-D),& n=\mathrm{0,1},...,D-1\\ \mathrm{pn}2\left(n\right){\mathrm{pn}2}^{*}(n+D),& n=D,2,...,N/2-1\end{array}\right.$

Because

With

All be the PN sequence, then

It is right to be similar to the complementary PN sequence of regarding new as

$\tilde{a}\&ap;[\tilde{p}\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">n</figure-callout>}1,\tilde{p}n2]$

$\tilde{b}\&ap;[\tilde{p}\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">n</figure-callout>}1,-\tilde{p}n2]$

It is relevant to define complementary difference

$R_d\left(k\right)=R_{\tilde{a}\tilde{a}}\left(k\right)+R\tilde{b}\tilde{b}\left(k\right)$

$\&ap;\underset{J=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\tilde{p}n1\left(j\right){\tilde{a}}^{*}(j+k)+\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\tilde{p}n2\left(j\right){\tilde{a}}^{*}(N/2+j+k)+$

$\underset{J=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\tilde{p}n1\left(j\right){\tilde{b}}^{*}(j+k)-\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\tilde{p}n2\left(j\right){\tilde{b}}^{*}(N/2+j+k)+$

$=\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\tilde{p}n1\left(j\right){[\tilde{a}(j+k)+\tilde{b}(j+k)]}^{*}+$

$\underset{j=0}{\overset{N/2-1}{\mathrm{\&Sigma;}}}\tilde{p}n2\left(j\right){[\tilde{a}(j+k+N/2)-\tilde{b}(j+k+N/2)]}^{*}$

By following formula as seen, this complementation difference is relevant can be respectively by coefficient

With

Two cross-correlators realize.

Right complementary character obtains comparatively ideal relevant nature in order to make full use of the PN complementary series, needs to search out in all PN sequences optimum PN sequence pn1, the pn2 structure obtain (a, b) complementary aperiodic autocorrelation sequence secondary lobe power minimum, promptly

$\underset{\mathrm{pn}}{\mathrm{<figure-callout\; id="1"\; label="min\; pn"\; filenames="H2009100901897E00043.png"\; state="\{\{state\}\}">min</figure-callout>}}\left(\frac{\underset{k\&NotEqual;0}{\mathrm{\&Sigma;}}{\left|R_c\left(k\right)\right|}^2}{{\left|R_c\left(0\right)\right|}^2}\right)$

As shown in figure 13, the invention allows for a kind of searching method of optimum PN complementary series, this method comprises the steps:

D1: selected nuclear PN sequence length N, generating length is the PN sequence of N, forms the PN sequence library;

PN sequence library construction method is specially, as fruit stone PN sequence length N=2 ⁿ-1, construct the M sequence that all length is N by the generator polynomial and the initial phase of n rank linear feedback shift register, form the PN sequence library; If step S1 center PN sequence length N is not 2 ⁿ-1 form, then constructing length respectively is 2 ^N-1The cyclic extensions of-1 M sequence and length are 2 ⁿBlocking of-1 M sequence, wherein n satisfies 2 ^N-1-1＜N＜2 ⁿ-1, two kinds of sequences are formed the PN sequence library.

D2: from the PN sequence library, choose a pn1 successively;

D3: from the PN sequence library, choose a pn2 successively;

D4: according to the building method of PN mutual-complementing code generate the PN complementary series to (a, b):

a＝[pn1，pn2]a＝[pn1，pn2(end：-1：1)]

Or

b＝[pn1，-pn2]b＝[pn2，-pn1(end：-1：1)]

D5: (a, complementary auto-correlation b) is R as a result in calculating _c(k):

$R_{\mathrm{aa}}\left(k\right)=\underset{j}{\mathrm{\&Sigma;}}a\left(j\right)a^{*}(j+k)$

$R_{\mathrm{bb}}\left(k\right)=\underset{j}{\mathrm{\&Sigma;}}b\left(j\right)b^{*}(j+k)$

R _c(k)＝R _aa(k)+R _bb(k)

D6: calculate R _cThe ratio P of secondary lobe power (k) and relevant peaks power _Side-lobe, and note power ratio and corresponding pn1, pn2:

$P_{\mathrm{side}-\mathrm{lobe}}=\frac{\underset{k\&NotEqual;0}{\mathrm{\&Sigma;}}{\left|R_c\left(k\right)\right|}^2}{{\left|R_c\left(0\right)\right|}^2}$

D7: if pn2 does not travel through the PN sequence library, then choose a new PN sequence, return D4 as pn2; Otherwise change D8 over to;

D8; If pn1 does not travel through the PN sequence library, then choose a new PN sequence as pn1, return D3; Otherwise change D9 over to;

D9: at all R _c(k) select the pn1 of minimum secondary lobe power correspondence in, pn2, the PN complementary series that is generated by its structure is to (a, b) optimum.

The optimum PN complementary series of choosing with the method applies in the described method and system of the various embodiments described above.

Above execution mode only is used to illustrate the present invention; and be not limitation of the present invention; the those of ordinary skill in relevant technologies field; under the situation that does not break away from the spirit and scope of the present invention; can also make various variations and modification; therefore all technical schemes that are equal to also belong to category of the present invention, and scope of patent protection of the present invention should be defined by the claims.

Claims (7)

1. the transmission method of a digital signal, the method comprising the steps of:

S1. treat that transmission signals is encoded, modulation treatment, obtain the data to be transmitted piece;

S2. the PN complementary series of alternately filling PN complementary series centering at the adjacent data interblock and carries out framing as training sequence, protection at interval or targeting sequencing;

S3. the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations, and send described Frame;

In step S2, described PN complementary series is to being with nuclear PN sequence pn1, pn2 be elementary cell the PN complementary series to (a, b), and satisfy structural model:

Pattern one: a=[pn1, pn2], b=[pn1 ,-pn2]; Or

Pattern two: a=[pn1 ,-pn2 (end:-1: 1)], b=[pn2, pn1 (end:-1: 1)]

Perhaps:

Described PN complementary series is to being that multi-stage cascade PN complementary series is to (a ⁽ⁿ⁾, b ⁽ⁿ⁾), the right basic complementary series of described multi-stage cascade PN complementary series to be described PN complementary series to (a, b), promptly (a is that the right first order cascade complementary series of described multi-stage cascade PN complementary series is right b), and when (a b) satisfies described pattern for the moment,

(a ⁽ⁿ⁾, b ⁽ⁿ⁾) satisfy structural model:

a ⁽ⁿ⁾＝[a ^(n-1)，b ^(n-1)]，b ⁽ⁿ⁾＝[a ^(n-1)，-b ^(n-1)]；

When (a is when b) satisfying described pattern two

(a ⁽ⁿ⁾, b ⁽ⁿ⁾) satisfy structural model:

a ⁽ⁿ⁾＝[a ^(n-1)，-b ^(n-1)(end:-1∶1)]，b ⁽ⁿ⁾＝[b ^(n-1)，a ^(n-1)(end:-1∶1)]，

1), pn2 (end:-1: 1) represent sequence after pn1, the pn2 backward respectively wherein, pn1 (end:-1:.

2. digital signal transmission method as claimed in claim 1; it is characterized in that; described data block is basic single carrier data block, multicarrier data block, or is the broad sense data block, and the data block of described broad sense is one or more master data pieces and protection combination at interval thereof.

3. the transmission method of digital signal as claimed in claim 1 is characterized in that, described coding comprises Space Time Coding or space-frequency coding mode, with the data to be transmitted piece that obtains to transmit on double antenna.

4. as the transmission method of each described digital signal among the claim 1-3, it is characterized in that described PN sequence comprises that length is 2 ⁿ-1 M sequence also comprises the blocking or the time domain binary sequence of random length of cyclic extensions, M sequence of M sequence.

5. the transmission system of a digital signal, this system comprises:

Signal processing module is used to treat that transmission signals is encoded, modulation treatment, obtains the data to be transmitted piece;

Framing module, the PN complementary series that is used for alternately filling PN complementary series centering at the adjacent data interblock and are carried out framing as training sequence, protection at interval or targeting sequencing;

Back end processing module is used for the Frame behind the framing is carried out digital-to-analogue conversion, rf modulations, and sends described Frame;

Described PN complementary series is to being with nuclear PN sequence pn1, pn2 be elementary cell the PN complementary series to (a, b), and satisfy structural model:

Pattern one: a=[pn1, pn2], b=[pn1 ,-pn2]; Or

Pattern two: a=[pn1 ,-pn2 (end:-1: 1)], b=[pn2, pn1 (end:-1: 1)]

Perhaps:

Described PN complementary series is to being that multi-stage cascade PN complementary series is to (a ⁽ⁿ⁾, b ⁽ⁿ⁾), the right basic complementary series of described multi-stage cascade PN complementary series to be described PN complementary series to (a, b), promptly (a is that the right first order cascade complementary series of described multi-stage cascade PN complementary series is right b), and when (a b) satisfies described pattern for the moment,

(a ⁽ⁿ⁾, b ⁽ⁿ⁾) satisfy structural model:

a ⁽ⁿ⁾＝[a ^(n-1)，b ^(n-1)]，b ⁽ⁿ⁾＝[a ^(n-1)，-b ^(n-1)]；

When (a is when b) satisfying described pattern two

(a ⁽ⁿ⁾, b ⁽ⁿ⁾) satisfy structural model:

a ⁽ⁿ⁾＝[a ^(n-1)，-b ^(n-1)(end:-1∶1)]，b ⁽ⁿ⁾＝[b ^(n-1)，a ^(n-1)(end:-1∶1)]，

1), pn2 (end:-1: 1) represent sequence after pn1, the pn2 backward respectively wherein, pn1 (end:-1:.

6. synchronous cross-correlator of the described digital signal transmission system receiver of claim 5, this correlator comprises a plurality of delay structures and two sub-correlators, it is characterized in that, the coefficient of described sub-correlator is nuclear PN sequence pn1, pn2, described nuclear PN sequence pn1, pn2 are that the PN complementary series is to (a, basic sequence b).

7. synchronous differential correlator of the described digital signal transmission system receiver of claim 5, this differential correlator comprises a plurality of delay structures and two sub-correlators, it is characterized in that the coefficient of described sub-correlator is the circulation difference of nuclear PN sequence pn1, pn2

Described nuclear PN sequence pn1, pn2 are that the PN complementary series is to (a, basic sequence b).

Images