CN1201514C - Implement method of ternary spread spectrum sequence coding in CDMA system - Google Patents

Abstract

The present invention discloses a realization method for coding ternary spread spectrum sequences in a code division multiple access (CDMA) system. A spread spectrum sequence code group is composed of basic pulses whose normalized amplitude and width are both 1, and the basic pulses have polarity. The method comprises the steps: firstly, giving the basic pulse number and the zero correlation zone length of an LA sequence to generate a basic sequence s whose length is N; then, generating a dyadic orthogonal sequence group whose length is m; expanding the dyadic orthogonal sequence group into a ternary sequence whose length is N; finally, multiplying the basic sequence s and each sequence of the ternary sequence group by bits to obtain a ternary spread spectrum sequence code group A. what's important that the basic sequence s is constructed by setting the relation of each pulse interval deltai and the zero correlation zone length Zcz and figuring out the pulse interval of the sequence. The spread spectrum sequence coding method is suitable for quasi-synchronous CDMA communication systems, reduces even eliminates common channel interference, enhances system capacity, and simplifies system design.

Description

The implementation method of ternary spread spectrum sequence coding in the code division multiple access system

Technical field

The present invention relates to the coding techniques of a kind of spread spectrum and multi-address radio communication, be meant the coding method of the frequency expansion sequence sign indicating number of a kind of low interference that works under the accurate method of synchronization or noiseless CDMA communication especially.

Background of invention

The function of wireless communication system is gradually become strong, and can provide the support to multiple business such as speech, data, images simultaneously, to satisfy the growing communication requirement of user.And in radio communication, be the most key to the utilization of frequency spectrum, code division multiple access (CDMA) technology improves the most effective means of the availability of frequency spectrum exactly.Compare with traditional frequency division multiple access (FDMA), time division multiple access wireless multiple access technology such as (TDMA), CDMA has soft capacity, anti-multipath and anti-interference or the like ability.

The capacity of cdma system depends on the interference level of system, disturbs more the mini system capacity just high more.In order further to reduce the interference in the code division multiple address communication system, people have proposed synchronous code division multiple access communication system, that is: make between base station and each user and strictly to keep synchronously, as adopting global positioning system (GPS) technology or other complicated high-precise synchronization technology or the like.At present, Walsh (Walsh) sign indicating number of synchronous code division multiple access communication system employing quadrature or A Daqi (Adachi) sign indicating number are as spread spectrum sequence code group.For mobile communication system, accurately guaranteeing not too easily synchronously of up link, and the multipath transmisstion of wireless channel makes system synchronization become difficult more, the intersymbol their cross correlation of Walsh or its yard of A Da only is zero synchronously the time, cross correlation value is non-vanishing when intersymbol is asynchronous, just exists multiple access to disturb.And,, power system capacity is restricted because the existence of near-far interference will further reduce the performance of synchronous code division multiple access communication system.In order to alleviate the influence of near-far interference as far as possible, in utility systems such as IS-95, adopted complicated fast power control technology.But the complexity that so can the increase system realizes has also increased the expense of control resource simultaneously, and then has increased system cost.

Therefore, think that the another kind of way that further reduces to disturb in the code division multiple address communication system is exactly: reduce the requirement of system to synchronization accuracy.For this reason, the someone proposes synchronously accurate or near-synchronous code division multiple address communication system in recent years, makes the synchronous error of system be controlled within the certain limit (as one or several chip period), and launched research work on spreading code design.More existing at present relevant patents, as: Chinese patent PCT/CN98/00151 (CN1175828A) " adopts a kind of ternary spread spectrum sequence code character with zero correlation block "; Japan Patent TY99002 (11-023252) " adopts a kind of binary spread spectrum sequence code group with zero correlation block "; Japan Patent PCT/JP97/03272 (JP271858/96) " adopts a kind of spread spectrum sequence code group with pectination frequency spectrum " or the like.But the correlation function of the frequency expansion sequence that proposes may be very big outside zero correlation block in two Japan Patents, if the system synchronization error has exceeded the scope of estimating, the interference that this kind frequency expansion sequence brings will be to be difficult to control.

Summary of the invention

By above-mentioned analysis as can be seen, the objective of the invention is to propose a kind of implementation method that is applied to the ternary spread spectrum sequence coding in low interference or the non-interference quasi-synchronous CDMA communication system, make other interference outside its reduction even the elimination noise, greatly improve power system capacity, reduce system simultaneously to power control and synchronous requirement, and realize simply, reduced the complexity that system realizes.

Generally, in ideal conditions, the frequency expansion sequence collection that uses in the cdma communication system should have following correlation properties:

1, the auto-correlation function of each frequency expansion sequence should be an impulse function, and promptly except that zero time delay, its value should be zero everywhere.

2, the cross-correlation function value of every pair of frequency expansion sequence should be zero everywhere.

Regrettably, no matter be binary, polynary, or sequence of complex numbers, the verified sequence sets with this desirable correlation properties is non-existent.To given sequence period and number, maximum auto-correlation function limit peak value of sequence sets and maximum cross correlation functional value can not be zero simultaneously, they are subjected to the restriction of some theoretical circles, when requiring one to diminish, another must increase, as strange (Welch) boundary of Weir, this De Nikefu (Sidelnikov) boundary etc.

Though can not design spread spectrum sequence code group with desirable auto-correlation and their cross correlation, can be at the quasi-synchronous CDMA system, design the zero correlation block spread spectrum sequence code group that has desirable correlation properties in the synchronous error scope of permission.This respect, Chinese patent PCT/CN98/00151 (CN1175828A) provides a good idea, has provided a kind of ternary spread spectrum sequence code character-big zone (LA, Large Area) sequence with zero correlation block.

So-called LA sequence, being basic pulse 1, that have polarity by normalization amplitude and width exactly forms, basic pulse does not wait on the time coordinate axle and is different, utilize this interval not wait and different pulse position and pulse polarity arranging and encodings, and this sequence has following feature:

1) main peak of auto-correlation function equals the number of basic pulse;

2) the submaximum value of auto-correlation and cross-correlation function has only 1,0 ,-1 three kind of situation;

3) there are a zero correlation block in auto-correlation and cross-correlation function near initial point.Here correlation function comprises that the cycle is relevant, aperiodic is relevant very relevant with the cycle.

As from the foregoing, the correlation function of LA sequence is very low outside zero correlation block, is 0,1 or-1, even the system synchronization error has exceeded the scope of estimating, also only has lower interference.The more important thing is that the LA sequence also has the zero correlation block of other sequence not available aperiodic of correlation function except that the zero correlation block of periodic correlation function, and according to the system performance analysis result, systematic function by the cycle and aperiodic correlation function value determine jointly.System is an example with big area synchronized code division multiple access (LAS-CDMA), adopts the LA sequence sets in its system, can make multiple access disturb (MAI) and intersymbol interference (ISI) to be suppressed significantly even eliminates, and makes neighbor cell interference (ACI) also reduce to minimum simultaneously.Therefore, can make that the LAS-CDMA system spectral efficiency is higher, transmission data rate is higher, translational speed is faster, comparable in theory CDMA2000 capacity is big more than 3 times, data transmission rate up to 5.53Mb/s can be provided on the 1.25MHz bandwidth, can adapt to the demand for development of packet switching and all-IP net.

But the LA sequence sets is with respect to sequence length, and the sequence number is obviously on the low side, and in other words, its supported user is few under identical sequence length, and the utilance of frequency spectrum is low.Because sequence sets if having more sequence, just means and can support more user that the availability of frequency spectrum is higher under the identical situation of sequence length.The present invention under the prerequisite that keeps the good correlation properties of LA sequence, has shortened the LA sequence length just at this fact widely, has promptly improved the utilance of frequency spectrum.In addition, space requirement can only have one to be any odd number greater than minimum interval (being zero correlation block) to LA sequence basic pulse in former patent, and all the other are even number, so, paired pulses limits at interval too much, can cause existing LA sequence longer, makes the sequence degradation.The present invention has removed this requirement just, constructs shorter LA sequence.

It is even number that the basic pulse of given LA sequence is counted m, and zero correlation section length is Z _Cz, the sequence s that at first to generate a length be N is referred to as the basic sequence of LA sequence.The distributing position of supposing basic pulse among the basic sequence s respectively is x ₁, x ₂..., x _m, make the interval of adjacent basic pulse be respectively δ ₁, δ ₂..., δ _M-1, that is: δ _i=x _I+1-x _i, i=1,2 ..., m-1.Establish δ again _m=N-x _m, these pulse spacings should satisfy:

1、δ _i≥Z _cz，1≤i≤m；

$2.\underset{k=i}{\overset{j}{\mathrm{\&Sigma;}}}{\mathrm{\&delta;}}_k\&NotEqual;\underset{k=s}{\overset{t}{\mathrm{\&Sigma;}}}{\mathrm{\&delta;}}_k,1\&le;i\&le;j<s\&le;t\&le;m;$

$3.\underset{k=i}{\overset{j}{\mathrm{\&Sigma;}}}{\mathrm{\&delta;}}_k\&NotEqual;\underset{k=s}{\overset{t}{\mathrm{\&Sigma;}}}{\mathrm{\&delta;}}_k,t-n<i<j<s\&le;m<t\&le;2m-2;$

δ wherein _k=δ _K-m, as k＞m.Also promptly all pulse spacings (comprise δ _m) all more than or equal to Z _Cz, and the difference of the position of any two basic pulses is different under modulo-N arithmetic.The autocorrelation of basic sequence s satisfies the characteristic 1 of LA sequence so), 2), 3).

Secondly, generating length is the binary orthogonal sequence group { b of m ¹, b ²..., b ^m, wherein $b^i=\{b_0^i,b_1^i,...,b_{m-1}^i\},i=\mathrm{1,2},...,M,$ Satisfy

$R_{b^i,b^j}\left(0\right)=0,i\&NotEqual;j$

As m ≡ 2 ⁿThe time, can adopt the Walsh sequence set as the orthogonal sequence group.Again the quadrature sequence set is done following expansion, generating length is the ternary sequence { c of N ¹, c ²..., c ^m}

At last, basic sequence s and ternary sequence set { c ¹, c ²..., c ^mIn each sequence step-by-step multiply each other, obtain ternary sequence set A={a ¹, a ²..., a ^M, wherein $a^i=\{S_0{C}_0^i,S_1{C}_1^i,...,S_{N-1}{C}_{N-1}^i\},$ A promptly is so-called LA sequence.

Correlation is determined fully by the autocorrelation performance of basic sequence s between the sequence of sequence sets A.Consider a ⁱ, a ^jPeriodic correlation function, 1≤i, j≤M, the condition 1 that satisfies according to the pulse spacing is as time delay τ＜Z _CzThe time, the non-zero entry in them can not met, and therefore has a zero correlation block Z _CzAccording to condition 2 and 3, to fixing time delay τ, non-zero entry is met once at the most in them, so the submaximum value has only 1,0 ,-1 three kind of situation.Strange correlation properties of aperiodic correlation properties and cycle also are that similarly the submaximum value also has only 1,0 ,-1 three kind of situation.Therefore A is the LA sequence sets, and the cycle is relevant, aperiodic is relevant and zero correlation block strange correlation function of cycle all equals Z _Cz

Basic sequence s sequence is the basis of LA sequence, and the distributing position x of pulse in the s sequence ₁, x ₂..., x _m, or pulse spacing δ ₁, δ ₂..., δ _mIt is the core of s sequence.That is to say: for basic sequence s, determined the pulse spacing of s, and then also just determined the position of distribution of pulses.Behind the basic pulse number and zero correlation section length of given LA sequence, the s sequence that constructs minimum or as far as possible little length is the most key.

In view of this, main purpose of the present invention just is to construct the s sequence of minimum or as far as possible little length, makes system when reducing interference and reducing implementation complexity, greatly improves power system capacity; And, reduce system to power control and synchronous requirement.

For achieving the above object, technical scheme of the present invention is achieved in that

The implementation method of ternary spread spectrum sequence coding in a kind of code division multiple access system, this spread spectrum sequence code group by normalization amplitude and width be 1 and basic pulse with polarity form, it comprises the steps: at least

The basic pulse number and the zero correlation section length of a. given LA sequence generate a basic sequence s that length is N;

B. generating length is the binary orthogonal sequence group of m, and this orthogonal sequence group can be the walsh sequence group, again this binary orthogonal sequence group is extended for the ternary sequence that length is N;

C. each sequence step-by-step of basic sequence s and ternary sequence set is multiplied each other, obtain ternary spread spectrum sequence code character A;

The method that importantly generates basic sequence s further comprises the following steps:

D. set each pulse spacing δ _iWith zero correlation section length Z _CzRelation, calculate pulse spacing of basic sequence s.

All basic pulses of described spread spectrum sequence code group are at interval all more than or equal to zero correlation section length Z _Cz, and the difference of the position of any two basic pulses is different under the computing of mode sequence length.This pulse spacing is an odd number, or is even number.

The auto-correlation function of arbitrary sequence has zero correlation block in zero displacement and zero displacement both sides in the described spread spectrum sequence code group, the cross-correlation function of any pair of sequences has zero correlation block in zero displacement and the zero both sides that is shifted in this spread spectrum sequence code group, and autocorrelation value and cross correlation value have only 1,0 and-1 outside zero correlation block.Wherein, correlation function comprises that the cycle is relevant, aperiodic is relevant very relevant with the cycle, and the zero correlation block of these three kinds of correlation functions all equates.

Three conditions according to such scheme and pulse spacing will satisfy can directly obtain building method one, and this method comprises the steps: at least

Step 1, make δ ₁=Z _Cz, δ ₂=Z _Cz+ 1, δ ₃=Z _Cz+ 2, n=3;

Step 2, for 1≤i＜j＜s≤t＜n, whether exist

$\underset{k=i}{\overset{j}{\mathrm{\&Sigma;}}}{\mathrm{\&delta;}}_k=\underset{k=s}{\overset{t}{\mathrm{\&Sigma;}}}{\mathrm{\&delta;}}_k+\mathrm{\&delta;}$ Or $\underset{k=i}{\overset{j}{\mathrm{\&Sigma;}}}{\mathrm{\&delta;}}_k=\mathrm{\&delta;},t-m<i<j<s\&le;n<t\&le;2m-2;$ If exist, then step 2 is continued in δ=δ+1;

If step 3 n=m-1 then judges whether to exist

$\underset{k=i}{\overset{j}{\mathrm{\&Sigma;}}}{\mathrm{\&delta;}}_k\&NotEqual;\underset{k=s}{\overset{t}{\mathrm{\&Sigma;}}}{\mathrm{\&delta;}}_k,t-m<i<j<s\&le;n<t\&le;2m-2;$ If, exist, then δ=δ+1 changes step 2 over to;

Step 4, make n=n+1, δ _m=δ, δ=δ+1.If n=m, δ ₁, δ ₂..., δ _mBe institute and ask, otherwise change step 2 over to.

But the pulse spacing in the building method one is strictly increasing, and in general, the sequence that the pulse spacing of incremental order is formed does not reach minimum length, for this reason, can method one be the basis, further improves algorithm, therefore proposes another kind of scheme:

The implementation method of ternary spread spectrum sequence coding in a kind of code division multiple access system, this spread spectrum sequence code group by normalization amplitude and width be 1 and basic pulse with polarity form, it comprises the steps: at least

The basic pulse number and the zero correlation section length of a. given LA sequence generate a basic sequence s that length is N;

B. generating length is the binary orthogonal sequence group of m, and this orthogonal sequence group can be the walsh sequence group, again this binary orthogonal sequence group is extended for the ternary sequence that length is N;

C. each sequence step-by-step of basic sequence s and ternary sequence set is multiplied each other, obtain ternary spread spectrum sequence code character A;

The method that importantly generates basic sequence s further comprises the following steps:

D. set each pulse spacing δ _iWith zero correlation section length Z _CzRelation, calculate pulse spacing of basic sequence s;

E. in the pulse spacing that calculates according to step b, generate zero correlation section length more than or equal to Z _CzAnd smaller or equal to Z _CzMore than one father's sequence of+N-1;

F. calculate the length of each father's sequence;

G. two father's sequences of picked at random with this sequence truncation, exchange the part of these two sequence correspondences in a position of selecting at random, produce two subsequences; Repeating step f is up to the subsequence that produces some;

H. calculate the length of each subsequence;

I. select a shortest above subsequence of length as new father's sequence;

J. after having moved official hour, choose the shortest sequence of length for separating.

Stipulated time in the step g among the subsequence of some and the step j, determine by the empirical value of zero correlation section length and umber of pulse.

Step g further may further comprise the steps: when the switching part of two new subsequences and switching part not interpulse is separated with when conflicting, only keep the pulse spacing that switching part does not conflict, the next bit from the conflict pulse spacing begins to regenerate new subsequence according to the pulse spacing that step b calculates then.Wherein, pulse spacing conflict is meant switching part and identical pulse spacing of switching part appearance not.

All basic pulses of described spread spectrum sequence code group are at interval all more than or equal to zero correlation section length Z _Cz, and the difference of the position of any two basic pulses is different under the computing of mode sequence length.This pulse spacing is an odd number, or is even number.

The auto-correlation function of arbitrary sequence has zero correlation block in zero displacement and zero displacement both sides in the above-mentioned spread spectrum sequence code group, the cross-correlation function of any pair of sequences has zero correlation block in zero displacement and the zero both sides that is shifted in this spread spectrum sequence code group, and autocorrelation value and cross correlation value have only 1,0 and-1 outside zero correlation block.Wherein, correlation function comprises that the cycle is relevant, aperiodic is relevant very relevant with the cycle, and the zero correlation block of these three kinds of correlation functions all equates.

This building method two specifically comprises following several steps:

Step 1, utilize method one to produce zero correlation section length more than or equal to Z _Cz, and smaller or equal to Z _CzThe n of+n-1 father's sequence;

Step 2, calculate the length of each father's sequence;

Step 3, intersection.That is: two father's sequences of picked at random are blocked them in a position of selecting at random, exchange their counterparts, produce two subsequences.Note the latter part of probably δ of these two sequences _iWith conflict ( condition 2 and 3 that does not promptly satisfy the pulse spacing) of front, then only keep all δ that do not conflict of front _i, establish k such δ altogether _i, utilize method one to generate new subsequence from the k+1 position.Repeat this operation, up to the subsequence that produces some;

Step 4, calculate the length of each subsequence;

Step 5, competition.Select n the shortest subsequence of length as new father's sequence;

Step 6, moved the stipulated time after, choose the shortest sequence of length for separating.

Wherein, " some " of " up to producing some subsequences " in the step 3; In the step 5 " n " of " a shortest n subsequence "; " stipulated time " of " having moved the stipulated time " in the step 6, these three numerical value obtain by empirical value, and it all has relation with zero correlation section length and umber of pulse, and in general, umber of pulse is many more, and these values are big more.Theoretically, these values are big more, and the LA sequence length that obtains is possible more minimum just, and promptly performance is good more.With LA sequence in table 2, the table 3 is example, and table 2, father's sequence number n of 3 are respectively 15,30, produce 40,80 of subsequences respectively at every turn, are defined as 10 minutes running time.

According to method two, can obtain ratio method one length shorter the LA sequence, shown in table 2 and 3.

Brief Description Of Drawings

Fig. 1 is LA sequence code character example of the present invention (with 8 basic pulses, the zero correlation head of district 16 is an example);

Fig. 2 is periodic auto-correlation function figure of the present invention (is example with sequence among Fig. 1 1);

Fig. 3 is periodic auto-correlation function figure of the present invention (is example with sequence among Fig. 1 2);

Fig. 4 is periodic cross-correlation functional arrangement of the present invention (is example with sequence 2 with sequence among Fig. 1 1);

Fig. 5 is non-periodic autocorrelation function figure of the present invention (is example with sequence among Fig. 1 1);

Fig. 6 is non-periodic autocorrelation function figure of the present invention (is example with sequence among Fig. 1 2);

Fig. 7 is cross-correlation function figure aperiodic of the present invention (is example with sequence 2 with sequence among Fig. 1 1);

Fig. 8 is a very relevant autocorrelation function graph (is example with sequence among Fig. 1 1) of cycle of the present invention;

Fig. 9 is a very relevant autocorrelation function graph (is example with sequence among Fig. 1 2) of cycle of the present invention;

Figure 10 is a very relevant autocorrelation function graph of cycle of the present invention (is example with sequence 2 with sequence among Fig. 1 1).

Implement mode of the present invention

The present invention is further described in more detail below in conjunction with drawings and the specific embodiments.

Table 1,2,3 has provided the pairing basic pulse of basic sequence s at interval, i.e. δ _i, i=1,2 ..., the value of m.They are according to δ ₁, δ ₂..., δ _mOrder be arranged in respectively between basic pulse in the jube.Given basic pulse is counted m and zero correlation section length Z _CzAfter, can obtain the pulse spacing of basic sequence s by question blank 1,2 or 3, thereby determine sequence s.

After given basic pulse is counted m, as long as zero correlation section length Z _Cz〉=m ²/ 4, work as m=4, just can obtain the basic sequence s of minimum length in theory at 8,16,32,64 o'clock, the interval of the basic pulse of its correspondence is as shown in table 1.As zero correlation section length Z _Cz＜m ²/ 4, utilize building method two, table 2 and table 3 have been listed the basic sequence s institute respective pulses interval of 16 basic pulses and 32 basic pulse smaller length respectively, and wherein, sequence has nearly all reached minimum length in the table 2, and sequence is worked as Z in the table 3 _CzMore than or equal to 160 o'clock, also reach or very near minimum length.

Table 1:Z _CZ〉=m ²/ 4 o'clock basic pulses at interval

Basic pulse number (m)	m 2/4	Z CZ≥m 2/ 4 o'clock basic pulses at interval
			4	4	{Z CZ，Z CZ+1，Z CZ+3，Z CZ+2}
8	16	{Z CZ，Z CZ+1，Z CZ+2，Z CZ+4，Z CZ+3，Z CZ+6，Z CZ+7，Z CZ+5}
			16	64	{Z CZ，Z CZ+1，Z CZ+2，Z CZ+3，Z CZ+4，Z CZ+5，Z CZ+6，Z CZ+7，Z CZ+8，Z CZ+9，Z CZ+ 10，Z CZ+14，Z CZ+13，Z CZ+15，Z CZ+11，2 CZ+12}
32	256	{Z CZ，Z CZ+1，Z CZ+2，Z CZ+3，Z CZ+4，Z CZ+5，Z CZ+6，Z CZ+7，Z CZ+8，Z CZ+9，Z CZ+ 10，Z CZ+11，Z CZ+12，Z CZ+13，Z CZ+14，Z CZ+15，Z CZ+16，Z CZ+17，Z CZ+18，Z CZ+19，Z CZ+20，Z CZ+21，Z CZ+23，Z CZ+27，Z CZ+22，Z CZ+25，Z CZ+26，Z CZ+30，Z CZ+24，Z CZ+29，Z CZ+31，Z CZ+28}
			64	1024	{Z CZ，Z CZ+1，Z CZ+2，Z CZ+3，Z CZ+4，Z CZ+5，Z CZ+6，Z CZ+7，Z CZ+8，Z CZ+9，Z CZ+ 10，Z CZ+11，Z CZ+12，Z CZ+13，Z CZ+14，Z CZ+15，Z CZ+16，Z CZ+17，Z CZ+18，Z CZ+19，Z CZ+20，Z CZ+21，Z CZ+22，Z CZ+23，Z CZ+24，Z CZ+25，Z CZ+26，Z CZ+27，Z CZ+28，Z CZ+29，Z CZ+30，Z CZ+31，Z CZ+32，Z CZ+33，Z CZ+34，Z CZ+35，Z CZ+36，Z CZ+37，Z CZ+38，Z CZ+39，Z CZ+40，Z CZ+41，Z CZ+42，Z CZ+43，Z CZ+44，Z CZ+45， Z CZ+46，Z CZ+48，Z CZ+49，Z CZ+50，Z CZ+52，Z CZ+56，Z CZ+47，Z CZ+53，Z CZ+54 ，Z CZ+60，Z CZ+51，Z CZ+55，Z CZ+62，Z CZ+59，Z CZ+57，Z CZ+63，Z CZ+61}

Table 2:16 basic pulse at interval

Z CZ	Length	Basic pulse at interval
			38	731	52，53，54，38，39，40，41，42，43，44，45，46，47，48，49，50
40	760	45，46，47，48，49，50，51，41，40，42，43，44，52，53，54，55
			42	792	47，48，49，50，51，52，53，43，42，44，45，46，54，55，56，57
44	826	49，50，51，52，53，54，55，45，44，46，47，48，56，57，58，61
			46	856	51，52，53，54，55，56，57，47，46，48，49，50，58，59，60，61
48	888	55，56，57，58，59，60，61，51，50，52，53，54，62，63，64，65
			50	920	57，58，59，60，61，62，63，53，52，54，55，56，64，65，66，67
52	952	57，58，59，60，61，62，63，53，52，54，55，56，64，65，66，67
			54	984	59，60，61，62，63，64，65，55，54，56，57，58，66，67，68，69
56	1016	61，62，63，64，65，66，67，57，56，58，59，60，68，69，70，71
			58	1048	63，64，65，66，67，68，69，59，58，60，61，62，70，71，72，73
60	1080	65，66，67，68，69，70，71，61，60，62，63，64，72，73，74，75
			62	1112	67，68，69，70，71，72，73，63，62，64，65，66，74，75，76，77

Table 3:32 basic pulse at interval

Z CZ	Length	Basic pulse at interval
			32	2473	44 45 46 47 48 32 33 34 37 35 38 36 41 40 42 52 49 56 51 97 43 55 63 126 75 142 176 58 79 66 122 565
34	2562	47 48 49 50 51 52 53 54 55 34 35 37 36 38 40 41 44 42 80 59 45 65 61 57 39 173 70 58 91 264 60 634
			36	2588	62 63 64 65 66 67 38 39 40 41 42 43 47 44 48 46 49 50 58 52 59 45 71 51 68 97 56 188 73 57 172 627
38
	40	2594	52 53 54 55 56 57 40 41 42 43 44 45 46 48 50 62 59 61 49 47 68 80 69 122 51 65 147 119 58 70 93 648
42				2644	70 71 72 73 74 75 42 43 44 45 46 47 49 48 53 50 54 51 57 107 62 63 55 59 69 65 111 159 167 95 168 400
	44	2663	72 73 44 45 46 47 48 49 50 51 52 54 53 56 55 58 62 57 66 68 61 63 59 74 105 104 77 78 203 131 158 444
46				2713	78 46 47 48 49 50 51 52 53 54 55 56 57 59 58 60 61 64 63 66 68 67 72 65 75 77 69 89 100 136 148 620
	48	2794	56 57 58 59 60 61 62 63 64 48 49 50 51 53 52 76 67 65 68 54 70 78 71 87 55 75 92 120 96 179 84 614
50				2864	65 66 67 68 69 52 53 54 55 57 56 58 59 60 62 63 75 64 70 72 73 71 76 74 84 96 61 80 111 86 179 628
	52
54		2962	70 71 72 73 74 75 54 55 56 58 57 59 61 60 62 63 64 67 65 68 66 78 77 79 83 90 80 99 128 110 87 701
	56			3018	77 78 56 57 58 59 60 61 62 63 64 65 66 57 68 69 70 74 71 76 75 84 72 81 94 90 138 85 91 142 106 639
58		3072	71 72 73 74 75 76 77 78 58 59 60 61 62 66 63 69 64 67 68 70 80 87 98 65 91 102 100 81 101 106 88 710
	60			3131	83 84 85 86 87 60 61 62 63 64 65 67 66 68 71 72 69 75 73 78 76 90 95 79 109 94 70 105 101 98 102 673
62		3140	78 79 80 81 82 83 84 85 62 63 64 65 67 66 69 68 72 71 73 75 70 102 91 88 76 74 106 98 96 130 114 628
	64			3229	94 95 96 64 65 66 67 68 69 70 71 72 7374 75 77 76 79 78 85 80 88 81 98 84 83 97 100 99 82 176 647
66		3303	74 75 76 77 78 79 80 81 69 66 67 70 68 71 72 84 86 85 82 90 87 73 91 83 92 89 93 104 122 99 147 693
	68			3403	80 81 82 83 84 85 86 87 88 70 68 69 71 72 73 74 75 76 77 79 78 90 89 107 92 98 129 110 94 111 103 742

70	3408	79 80 81 82 83 84 85 86 87 88 89 90 91 92 70 71 72 73 74 76 75 93 77 78 111 95 96 101 106 99 103 741
			72	3506	88 89 90 91 92 93 94 95 96 74 72 73 75 77 78 76 80 82 79 84 87 81 83 99 98 102 104 113 85 116 108 752
74	3543	86 87 88 89 90 91 92 74 75 76 77 78 79 80 81 82 83 84 85 93 99 96 95 98 103 100 97 101 141 115 150 678
			76	3569	110 111 112 113 114 115 116 117 80 81 82 83 84 85 86 88 87 89 90 91 96 93 95 97 94 92 101 98 108 99 133 529
78
	80
82		3584	101 102 103 104 105 106 107 108 109 110 111 83 82 84 85 86 88 89 87 91 92 97 90 114 94 99 126 117 118 98 116 482
	84			3817	104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 85 86 84 88 92 91 90 87 89 99 100 97 94 120 102 141 607
86		3824	112 113 86 87 88 89 90 91 92 93 94 96 95 97 99 98 100 102 101 103 104 105 106 109 114 108 120 107 111 123 135 656
	88			3834	107 108 109 96 97 98 99 100 101 102 104 105 106 110 103 115 111 112 113 114 116 124 117 121 118 125 120 122 127 138 126 370
90
	92
94
	96
98		4060	136 104 105 106 107 108 109 110 111 112 113 114 115 117 116 118 119 120 121 122 123 124 126 125 130 127 133 128 131 137 129 364
	100
102
	104
106				4292	138 139 140 141 106 107 108 109 110 111 112 113 114 115 118 116 119 117 121 122 120 124 125 126 127 128 130 133 129 132 134 508
	108	4375	126 127 128 129 130 131 132 133 134 135 136 137 138 139 111 112 110 114 113 116 117 121 115 120 123 118 119 143 141 148 142 437
110
	112			4394	129 130 131 132 133 134 135 136 137 121 120 122 123 124 125 126 128 127 151 140 142 138 139 144 143 141 153 149 146 147 154 194
114
	116
118
	120
122		4636	143 144 145 146 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 148 149 147 152 155 153 157 156 314
	124
126				4671	143 144 145 146 147 148 149 128 129 130 131 132 133 134 135 136 137 138 140 152 153 155 151 150 154 157 141 139 142 170 156 226
	128
130		4757	150 151 152 153 154 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 155 156 157 158 160 163 161 164 194
	132
134				4913	168 169 170 171 136 137 138 139 140 141 142 143 144 145 148 146 149 147 151 152 150 154 155 156 157 158 160 161 153 164 159 210
	136
138		4937	165 166 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 170 164 171 188
	140			5079	156 157 158 159 160 161 162 163 164 165 166 167 142 140 141 143 144 145 146 148 147 150 149 151 153 152 168 170 171 174 173 234
142		5149	171 172 173 174 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 170 178 179 200
	144
146				5191	154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 147 148 149 150 146 152 151 153 171 170 173 172 175 174 176 200
	148	5261	174 148 149 150 151 152 153 154 155 156 157 159 158 160 161 162 163 164 165 166 167 168 169 170 171 172 173 175 176 177 178 208
150				5323	158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 151 152 153 154 150 156 155 157 175 174 177 176 179 178 180 208
	152	5374	181 152 153 154 155 156 157 158 159 160 162 161 164 163 165 166 168 167 169 170 171 172 173 174 175 176 177 179 183 178 182 194

154	5481	182 183 184 185 186 187 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 172 173 174 175 176 178 177 179 216
			156	5507	175 176 177 156 157 158 159 160 161 162 163 164 165 166 168 171 167 170 173 169 178 172 174 180 179 181 182 184 189 183 185 203
158	5591	183 184 185 158 159 160 161 162 163 164 165 166 168 167 169 171 170 172 174 175 173 177 176 178 180 179 181 182 188 187 189 225
			160	5629	189 190 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 187 186 191 201
162	5726	193 162 163 164 165 166 167 168 169 170 171 173 172 174 175 176 177 179 178 180 181 182 183 184 185 186 187 188 191 189 196 232
			164	5755	186 187 188 164 165 166 167 168 169 170 171 174 173 175 176 177 172 178 179 180 182 181 183 184 185 189 190 191 192 195 194 204
166	5822	195 166 167 168 169 170 171 172 173 174 176 175 178 177 179 180 182 181 183 184 185 186 187 188 189 190 191 192 194 197 196 207
			168	5895	176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 169 170 171 172 168 174 173 175 193 192 195 194 197 196 198 222
170	5959	178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 171 172 173 174 170 176 175 177 195 194 197 196 199 198 200 224
			172	6022	182 183 184 185 186 187 188 189 190 191 192 193 194 195 173 174 175 176 172 178 177 179 180 204 196 197 198 199 181 205 200 219
174	6069	182 183 184 185 186 187 188 189 190 191 192 193 194 176 174 177 175 178 179 180 181 195 196 197 198 199 202 200 203 201 204 210
			176	6150	186 187 188 189 190 191 192 193 194 195 196 197 198 199 177 178 179 180 176 182 181 183 184 208 200 201 202 203 185 209 204 223
178	6197	186 187 188 189 190 191 192 193 194 195 196 197 198 180 178 181 179 182 183 184 185 199 200 201 202 203 206 204 207 205 208 214
			180	6269	206 180 181 182 183 184 185 186 187 188 189 191 190 192 193 194 195 196 197 198 199 200 201 202 203 204 205 207 208 209 210 224
182	6332	212 213 214 182 183 184 185 186 187 188 189 190 191 192 193 195 194 197 196 199 198 200 201 202 204 205 203 207 208 206 211 217
			184	6289	192 193 194 195 196 197 198 199 200 201 202 203 204 186 184 187 185 188 189 190 191 205 206 207 208 209 212 210 213 211 214 220
186	6453	194 195 196 197 198 199 200 201 202 203 204 205 206 188 186 189 187 190 191 192 193 207 208 209 210 211 214 212 215 213 216 222
			188	6517	196 197 198 199 200 201 202 203 204 205 206 207 208 190 188 191 189 192 193 194 195 209 210 211 212 213 216 214 217 215 218 224
190	6581	198 199 200 201 202 203 204 205 206 207 208 209 210 192 190 193 191 194 195 196 197 211 212 213 214 215 218 216 219 217 220 226
			192	6645	200 201 202 203 204 205 206 207 208 209 210 211 212 194 192 195 193 196 197 198 199 213 214 215 216 217 220 218 221 219 222 228
194	6709	202 203 204 205 206 207 208 209 210 211 212 213 214 196 194 197 195 198 199 200 201 215 216 217 218 219 222 220 223 221 224 230
			196	6773	204 205 206 207 208 209 210 211 212 213 214 215 216 198 196 199 197 200 201 202 203 217 218 219 220 221 224 222 225 223 226 232
198	6837	206 207 208 209 210 211 212 213 214 215 216 217 218 200 198 201 199 202 203 204 205 219 220 221 222 223 226 224 227 225 228 234
			200	6901	208 209 210 211 212 213 214 215 216 217 218 219 220 202 200 203 201 204 205 206 207 221 222 223 224 225 228 226 229 227 230 236
202	6965	210 211 212 213 214 215 216 217 218 219 220 221 222 204 202 205 203 206 207 208 209 223 224 225 226 227 230 228 231 229 232 238
			204	7029	212 213 214 215 216 217 218 219 220 221 222 223 224 206 204 207 205 208 209 210 211 225 226 227 228 229 232 230 233 231 234 240
206	7093	214 215 216 217 218 219 220 221 222 223 224 225 226 208 206 209 207 210 211 212 213 227 228 229 230 231 234 232 235 233 236 242
			208	7157	216 217 218 219 220 221 222 223 224 225 226 227 228 210 208 211 209 212 213 214 215 229 230 231 232 233 236 234 237 235 238 244

210	7220	219 210 211 212 213 214 216 215 217 218 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 240 239 245
			212	7281	234 235 236 237 238 239 240 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 241 242 244
214	7349	222 223 224 225 226 227 228 229 230 231 232 233 234 216 214 217 215 218 219 220 221 235 236 237 238 239 242 240 243 241 244 250
			216	7413	224 225 226 227 228 229 230 231 232 233 234 235 236 218 216 219 217 220 221 222 223 237 238 239 240 241 244 242 245 243 246 252
218	7473	240 241 242 243 244 245 246 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 247 248 250
			220	7536	243 244 245 246 247 220 221 222 223 224 225 226 227 228 230 229 231 233 232 234 236 238 237 239 240 241 242 248 249 250 251 235
222	7601	244 245 246 247 248 249 250 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 251 252 254
			224	7664	247 248 249 250 251 224 225 226 227 228 229 230 231 232 234 233 235 237 236 238 240 242 241 243 244 245 246 252 253 254 255 239
226	7728	249 250 251 252 253 226 227 228 229 230 231 232 233 234 236 235 237 239 238 240 242 244 243 245 246 247 248 254 255 256 257 241
			228	7792	251 252 253 254 255 228 229 230 231232 233 234 235 236 238 237 239 241 240 242 244 246 245 247 248 249 250 256 257 258 259 243
230	7857	252 253 254 255 256 257 258 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 259 260 262
			232	7920	255 256 257 258 259 232 233 234 235 236 237 238 239 240 242 241 243 245 244 246 248 250 249 251 252 253 254 260 261 262 263 247
234	7984	257 258 259 260 261 234 235 236 237 238 239 240 241 242 244 243 245 247 246 248 250 252 251 253 254 255 256 262 263 264 265 249
			236	8049	258 259 260 261 262 263 264 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 265 266 268
238	8112	261 262 263 264 265 238 239 240 241 242 243 244 245 246 248 247 249 251 250 252 254 256 255 257 258 259 260 266 267 268 269 253
			240	8176	263 264 265 266 267 240 241 242 243 244 245 246 247 248 250 249 251 253 252 254 256 258 257 259 260 261 262 268 269 270 271 255
242	8240	265 266 267 268 269 242 243 244 245 246 247 248 249 250 252 251 253 255 254 256 258 260 259 261 262 263 264 270 271 272 273 257
			244	8304	267 268 269 270 271 244 245 246 247 248 249 250 251 252 254 253 255 257 256 258 260 262 261 263 264 265 266 272 273 274 275 259
246	8368	269 270 271 272 273 246 247 248 249 250 251 252 253 254 256 255 257 259 258 260 262 264 263 265 266 267 268 274 275 276 277 261
			248	8432	271 272 273 274 275 248 249 250 251 252 253 254 255 256 258 257 259 261 260 262 264 266 265 267 268 269 270 276 277 278 279 263
250	8496	273 274 275 276 277 250 251 252 253 254 255 256 257 258 260 259 261 263 262 264 266 268 267 269 270 271 272 278 279 280 281 265
			252	8560	275 276 277 278 279 252 253 254 255 256 257 258 259 260 262 261 263 265 264 266 268 270 269 271 272 273 274 280 281 282 283 267
254	8624	277 278 279 280 281 254 255 256 257 258 259 260 261 262 264 263 265 267 266 268 270 272 271 273 274 275 276 282 283 284 285 269
			256	8688	279 280 281 282 283 256 257 258 259 260 261 262 263 264 266 265 267 269 268 270 272 274 273 275 276 277 278 284 285 286 287 271

Be spaced apart example with basic pulse in the table 1, illustrate how to utilize the basic pulse that provides to construct corresponding LA sequence at interval.Suppose that given basic pulse counts m=8, zero correlation block Z _Cz=16,1 obtain corresponding basic pulse { δ at interval by tabling look-up _i, i=1 ..., 8}={16,17,18,20,19,22,23,21}, then motif is classified as:

Wherein, " ... " representative element 0.

M the basic pulse that obtains basic sequence s be at interval or behind the distributing position, is that the orthogonal sequence code character of m is arranged basic pulse polarity by certain length again, generates spread spectrum sequence code group.Here select for use Walsh sequence set W as the orthogonal sequence group:

W ¹＝{1，1，1，1，1，1，1，1}

W ²＝{1，-1，1，-1，1，-1，1，-1}

W ³＝{1，1，-1，-1，1，1，-1，-1}

W ⁴＝{1，-1，-1，1，1，-1，-1，1}

W ⁵＝{1，1，1，1，-1，-1，-1，-1}

W ⁶＝{1，-1，1，-1，-1，1，-1，1}

W ⁷＝{1，1，-1，-1，-1，-1，1，1}

W ⁸＝{1，-1，-1，1，-1，1，1，-1}

The polarity of basic sequence s basic pulse rearranges through sequence set W, obtains the set A of 8 LA sequences, that is: sequence 1--a ¹, sequence 2--a ², sequence 3--a ³, sequence 4--a ⁴, sequence 5--a ⁵, sequence 6--a ⁶, sequence 7--a ⁷, sequence 8--a ⁸Its zero correlation block Z _Cz=16, as shown in Figure 1.

Referring to Fig. 2 and Fig. 3, they are respectively the periodic auto-correlation function figure of sequence 1 and sequence 2 among Fig. 1.Other sequence has the periodic auto-correlation function of all fours, and promptly time delay drops on (16,16) when interior, and its periodic auto-correlation function value is zero, and autocorrelation value has only 1,0 the cycle outside this ,-1 three kind of situation.

Referring to Fig. 4, it is the periodic cross-correlation functional arrangement of sequence 1 and sequence 2 among Fig. 1.Other arbitrary sequence is to having the periodic cross-correlation function of all fours, and promptly time delay drops on (16,16) when interior, and its periodic cross-correlation functional value is zero, and the periodic cross-correlation value has only 1,0 outside this ,-1 three kind of situation.

Referring to Fig. 5 and Fig. 6, they are respectively the non-periodic autocorrelation function figure of sequence 1 and sequence 2 among Fig. 1.Other sequence has the non-periodic autocorrelation function of all fours, and promptly time delay drops on (16,16) when interior, and its non-periodic autocorrelation function value is zero, and in addition, aperiodic, autocorrelation value had only 1,0 ,-1 three kind of situation.

Referring to Fig. 7, it is cross-correlation function figure aperiodic of sequence 1 and sequence 2 among Fig. 1.Other arbitrary sequence is to having cross-correlation function aperiodic of all fours, and promptly time delay drops on (16,16) when interior, and its periodic cross-correlation functional value is zero, and aperiodic, cross correlation value had only 1,0 outside this ,-1 three kind of situation.

Referring to Fig. 8 and Fig. 9, they are respectively the strange autocorrelation function graphs of cycle of sequence 1 and sequence 2 among Fig. 1.Other sequence has the strange auto-correlation function of cycle of all fours, and when promptly time delay dropped on (16,16) family, strange auto-correlation function value of its cycle was zero, and strange autocorrelation value has only 1,0 the cycle outside this ,-1 three kind of situation.

Referring to Figure 10, it is the strange cross-correlation function figure of cycle of sequence 1 and sequence 2 among Fig. 1.Other arbitrary sequence is to strange cross-correlation function of the cycle with all fours, and promptly time delay drops on (16,16) when interior, and strange cross-correlation function value of its cycle is zero, and strange cross correlation value has only 1,0 the cycle outside this ,-1 three kind of situation.

The above is preferred embodiment of the present invention only, is not to be used to limit protection scope of the present invention.

Claims (16)

1, the implementation method of ternary spread spectrum sequence coding in a kind of code division multiple access system, this spread spectrum sequence code group by normalization amplitude and width be 1 and basic pulse with polarity form, it comprises the steps: at least

The basic pulse number and the zero correlation section length of a. given LA sequence generate a basic sequence s that length is N;

B. generating length is the binary orthogonal sequence group of m, again this binary orthogonal sequence group is extended for the ternary sequence that length is N;

C. each sequence step-by-step of basic sequence s and ternary sequence set is multiplied each other, obtain ternary spread spectrum sequence code character A;

It is characterized in that the method that generates basic sequence s further comprises the following steps:

D. set each pulse spacing δ _iWith zero correlation section length Z _CzRelation, calculate pulse spacing of basic sequence s.

2, method according to claim 1 is characterized in that, also comprises the steps:

E. in the pulse spacing that calculates according to step b, generate zero correlation section length more than or equal to Z _CzAnd smaller or equal to Z _CzMore than one father's sequence of+N-1;

F. calculate the length of each father's sequence;

G. two father's sequences of picked at random with this sequence truncation, exchange the part of these two sequence correspondences in a position of selecting at random, produce two subsequences; Repeating step f is up to the subsequence that produces some;

H. calculate the length of each subsequence;

I. select a shortest above subsequence of length as new father's sequence;

J. after having moved official hour, choose the shortest sequence of length for separating.

3, coding method according to claim 2 is characterized in that: all basic pulses of described spread spectrum sequence code group are at interval all more than or equal to zero correlation section length Z _Cz, and the difference of the position of any two basic pulses is different under the computing of mode sequence length.

4, according to claim 1 or 3 described coding methods, it is characterized in that: the described pulse spacing is an odd number, or is even number.

5, coding method according to claim 1, it is characterized in that: the auto-correlation function of arbitrary sequence has zero correlation block in zero displacement and zero displacement both sides in the described spread spectrum sequence code group, the cross-correlation function of any pair of sequences has zero correlation block in zero displacement and the zero both sides that is shifted in this spread spectrum sequence code group, and autocorrelation value and cross correlation value have only 1,0 and-1 outside zero correlation block.

6, coding method according to claim 5 is characterized in that: described correlation function comprises that the cycle is relevant, aperiodic is relevant very relevant with the cycle, and the zero correlation block of these three kinds of correlation functions all equates.

7, coding method according to claim 1 is characterized in that: the orthogonal sequence group described in the step b is the walsh sequence group.

8, coding method according to claim 2 is characterized in that: all basic pulses of described spread spectrum sequence code group are at interval all more than or equal to zero correlation section length Z _Cz, and the difference of the position of any two basic pulses is different under the computing of mode sequence length.

9, according to claim 2 or 8 described coding methods, it is characterized in that: the described pulse spacing is an odd number, or is even number.

10, coding method according to claim 2, it is characterized in that: the auto-correlation function of arbitrary sequence has zero correlation block in zero displacement and zero displacement both sides in the described spread spectrum sequence code group, the cross-correlation function of any pair of sequences has zero correlation block in zero displacement and the zero both sides that is shifted in this spread spectrum sequence code group, and autocorrelation value and cross correlation value have only 1,0 and-1 outside zero correlation block.

11, coding method according to claim 10 is characterized in that: described correlation function comprises that the cycle is relevant, aperiodic is relevant very relevant with the cycle, and the zero correlation block of these three kinds of correlation functions all equates.

12, coding method according to claim 2 is characterized in that: the subsequence of some is determined by the empirical value of zero correlation section length and umber of pulse in the step g.

13, coding method according to claim 2, it is characterized in that step g further may further comprise the steps: when the switching part of two new subsequences and switching part not interpulse is separated with when conflicting, only keep the pulse spacing that switching part does not conflict, the next bit from the conflict pulse spacing begins to regenerate new subsequence according to the pulse spacing that step b calculates then.

14, coding method according to claim 13 is characterized in that: the conflict of described pulse spacing is meant switching part and identical pulse spacing of switching part appearance not.

15, coding method according to claim 2 is characterized in that: the stipulated time among the step j is determined by the empirical value of zero correlation section length and umber of pulse.

16, coding method according to claim 2 is characterized in that: the orthogonal sequence group described in the step b is the walsh sequence group.

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