CN1780164A - Frequency-hopping pattern generation in frequency-hopping telecommunication net - Google Patents

Abstract

A method for generating frequency hopping pattern of frequency-hopping communication network is disclosed. Its system is composed of n-class m sequence generator, binary sequence generator, vector mapping converter, and frequency-hopping control word unit. Said method includes such steps as generating signals by binary sequence generator, non-linear conversion, vector mapping with m sequence to obtain function set, and using each of the functions as the frequency control word of frequency hopping pattern to generate said pattern.

Description

The frequency hopping pattern production method of frequency hopping communications networks

Technical field

The present invention relates to a kind of frequency hopping communications technology, especially a kind of frequency hopping pattern production method of frequency hopping communications networks.

Background technology

Frequency hopping communications is a kind of technology that belongs to spread spectrum communication, has advantages such as anti-interference, anti-intercepting and capturing, is widely used in the military communication field.So-called frequency hopping refers to that communication transmitter carries a kind of communication mode of information by the different frequency of emission.In order to reach the anti-purpose of intercepting and capturing of frequency hopping communications, the common frequency hopping that controls transmitter with pseudo noise sequence, this presents pseudo-random characteristics with regard to the rule that makes frequency hopping, if the identical pseudo noise sequence of generation that receiver can not be synchronous then can't produce the frequency identical with transmitter and jump metric rule (being frequency hopping pattern again).Can not synchronously produce the receiver of identical frequency hopping pattern, be can't be real-time the demodulation emission Frequency Hopping Signal that comes.In other words, want not make Frequency Hopping Signal to be intercepted and captured, preferably use complicated frequency hopping pattern by the people---promptly use complicated pseudo random sequence.So present frequency-hopping receiver and transmitter all use the more linear shift register of progression, produce the pseudo random sequence of longer cycle.For example: use the m sequence, M sequence, Gold sequence etc.What wherein the m sequence was used in frequency hopping communications is more extensive.But the pseudo random sequence that the pseudo-random sequence generator of prior art produces is easy to be cracked owing to use linear shift register to produce.If adopt the nonlinear function generator to produce, can not guarantee usually that again jump frequency between each frequency hopping radio set of frequency hopping network does not overlap or collides.The present invention allows the frequency hopping pattern that produces by present technique both have higher complexity, can guarantee again can to guarantee when being used for frequency hopping network that frequency that each frequency hopping platform uses does not overlap and collides.

Technical scheme of the present invention: a kind of frequency hopping pattern production method of frequency hopping communications networks comprises n level m sequence generator unit, binary sequence generation unit, vector mapping transformation unit and frequency hopping commands for controlling word cell; The signal that binary sequence generator unit produces is by after the nonlinear transformation, enter vector mapping transformation unit, after carrying out vector mapping with the m sequence, changed original m sequence hopping rule, become the function set that obtains after the Nonlinear Mapping, each function in this set can be as the frequency control word of the frequency hopping pattern of a frequency hopping communications network, thereby produces the frequency hopping pattern after the mapping, form new frequency hopping control word, constitute frequency hopping commands for controlling word cell.

Vector mapping transformation unit is by binary pseudo-random sequence generator and corresponding linear displacement device, and nonlinear combination logic module and mould 2 add the logic device and form.

Pseudo-random sequence generator is the generation circuit of the sequence of m sequence or M sequence or Gold sequence or additive method generation.

Advantage of the present invention:

The pseudo random sequence of prior art, is easy to be cracked as the frequency hopping instruction of frequency hopping communications through any conversion or mapping.For example, a n level pseudorandom m-sequence, if when producing with linear shift register, its cycle is long to be L=2 ⁿ-1.To instead release the generator polynomial of this m sequence and corresponding linear shift register circuit structure, do not need to treat that a sequence period sign indicating number all obtains after, just can obtain.The explanation of the achievement of modern mathematics research, only need to obtain this sequence more than or equal to 2n continuous " 0 " " 1 " sign indicating number, just can instead release the structure of its generator polynomial and its linear shift register.And, owing to changed original frequency hopping rule, and be transformed to non-linearly by after the mapping, complicated degree of analysis will be increased greatly.For example, the frequency hopping control word after some conversion on rule, does not see it being the m sequence fully.

Description of drawings

Fig. 1 is the logical circuitry of a n level m sequence generator

Fig. 2 produces circuit for control word;

Fig. 3 is the structured flowchart after Fig. 2 and Fig. 4 merge

Fig. 4 produces logical circuit for hinting obliquely at function

Fig. 5 is a principle of the invention block diagram

Embodiment

Prior art is: for the m-sequence generator, suppose to be made up of n level shift register, then this sequence period length is L=2 ⁿ-1, in this sequence, get 0,1 element that the n position is faced mutually continuously arbitrarily, as a kind of state of m-sequence, then total L different state.Appoint and get one of them state as initial state, just can generate a m-sequence, just the initial state difference has determined the difference of the phase place of this m-sequence.For frequency hopping communications networks, suppose to be up to L user, so can a shared m-sequence generator; Maximum number of user u＜L in network, and during [L/U]=Q, also can allow and can stagger l between each user to Q chip { integer of x fractions omitted part is got in [x] representative } here.The general figure place of getting the frequency hopping control command is a n continuous binary element, and several chips of can being separated by between the used control word of frequency hopping mobile station, like this, can guarantee can not produce the frequency collision.

Because the frequency hopping pattern that adopts this method to produce does not carry out mapping transformation to the m-sequence, so, crack for a hostile side easily, a kind of L-dimension is shone upon by the base vector that the state of m-sequence constitutes, produce the method for the frequency hopping pattern of frequency hopping communications network so provide here.

The solution of the present invention is, supposes that a pseudo-random sequence generator has m level linear shift register, and the Cycle Length of the pseudo random sequence that it produced is L (m sequence, L=2 ⁿ-1, to M sequence, L=2 ⁿ), n is a m-shift register sequential machine progression.In this sequence, to appoint and get n consecutive " 0 ", " 1 " element combinations is as the basic vector of a frequency hopping control; Like this, in the m sequence, L different basic vector should be arranged altogether, constitute a vector space:

V _L＝(v ₁，v ₂，……，v _L-1，v _L) (1)

All contain in the set of these vectors each vector element one by one by another P-n dimensional vector n set K with this pseudo random sequence _PShine upon, each vector after the mapping is as the frequency control word of new frequency hopping pattern.Then will compare

V _L=(v ₁, v ₂..., v _L-1, v _L) complexity improve greatly.

Here, suppose

K _P＝(k ₁，k ₂，……，k _P-1，k _P) (2)

K _PIn each element obtain through Nonlinear Mapping by different P state among another binary sequence b (x).Here, b (x) can be some m-sequences, M-sequence, the binary sequence with sufficient length cycle that Gold-sequence or additive method produce.

Fig. 1 is the logical circuitry of a n level m sequence generator, and its generating function is

f(x)＝1+c ₁x+c ₂x ²+……+c _n-1x ^n-1+c _nx ⁿ………(3)

Logical circuit is made of n shift register, and Ci is corresponding tap coefficient, and is a modulo 2 adder.Output sequence is a (x).

Each n level shift register state of frequency hopping pattern generator among Fig. 1 is as a basic vector that produces frequency hopping pattern, and the set of these vectors is V _L, L=2 ⁿ-1; Corresponding m-sequence is output as a (x), successively the every n of this sequence the position of facing mutually as a base vector (truncated sequence), then can constitute the vector space of a L-dimension altogether:

V _L＝(v ₁，v ₂，……，v _L-1，v _L)；

Can be V _LEach element v _iAs a frequency hopping control word, here

V _i＝(a _i，a _i+1，a _i+2，…，a _i+n-1)。

The obvious V here _LAs the frequency hopping pattern sequence, its complexity is fairly simple.

Be provided with another P-n dimensional vector n space K _P=(k ₁, k ₂..., k _P-1, k _P), k _P=[B _{1, P}(X), B _{2, P}(X), B _{2, P}(X) ... B _{N, P}(X)]; B _{N, P}(X) represent the output of n in the P time chart 2 non-linear logical circuit.To v _LCarry out following mapping:

$V_l{|}_{K_P}\&DoubleRightArrow;\left[\begin{array}{c}{K}_1{V}_L\\ K_2{V}_L\\ .\\ .\\ .\\ K_P{V}_L\end{array}\right]\left[\begin{array}{cccc}{K}_1{V}_1& K_1{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="A20041006028000091.png,A20041006028000092.png"\; state="\{\{state\}\}">V</figure-callout>}}_2& ......& K_1{V}_L\\ K_2{V}_1& K_2{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="A20041006028000091.png,A20041006028000092.png"\; state="\{\{state\}\}">V</figure-callout>}}_2& ......& K_2{V}_L\\ .& .& & \\ .& .& & \\ .& .& & \\ K_P{V}_1& {\mathrm{<figure-callout\; id="2"\; label="K\; P\; V"\; filenames="A20041006028000091.png,A20041006028000092.png"\; state="\{\{state\}\}">K</figure-callout>}}_P{V}_{}{}_2& ......& K_P{V}_L\end{array}\right]=W_{P,L}......\left(4\right)$

Then in (4), total pxl frequency hopping controlled vector.Produce the source with a m-sequence as a basic frequency hopping pattern, and with another one binary code metasequence as transformation function coefficients, carry out conversion and produce a frequency hopping pattern that is not easy to crack.Can adopt method as shown in Figure 5.Comprise n level m sequence generator unit, binary sequence generation unit, vector mapping transformation unit and frequency hopping commands for controlling word cell; The signal that binary sequence generator unit produces is by after non-linear converter's conversion, enter vector mapping transformation unit, after carrying out vector mapping with the m sequence, changed original m sequence hopping rule, become the function set that obtains after the Nonlinear Mapping, each function in this set can be as the frequency control word of the frequency hopping pattern of a frequency hopping communications network, thereby produces the frequency hopping pattern after the mapping, form new+frequency hopping control word, constitute frequency hopping commands for controlling word cell.

Here, for non-network hop set, its m-sequence progression can complexity as required be selected; Its mapping function also can adopt and can make the uniform at random control method of frequency hopping instruction.

The frequency hopping code word that then available at any one time following transforming function transformation function produces:

$\mathrm{Tpz}\left(i\right)=f_{i,l}^n\left(x\right)\&CirclePlus;B\left(x\right)=(A_i\&CirclePlus;B_i,A_{i+1}\&CirclePlus;B_{i+1},\&CenterDot;\&CenterDot;\&CenterDot;,A_{i+n-1}\&CirclePlus;B_{i+n-1})...\left(5\right)$

The circuit structure that formula (5) is implemented as shown in Figure 2;

Fig. 2 produces circuit for control word; B _{1, Q}(x).。。, B _{N, Q}(x) circuit by Fig. 4 produces W ₁, W ₂... W _N-2, W _nThe binary condition element set of frequency hopping control word for output.B (X) function produces logic circuit structure as shown in Figure 4, and hinting obliquely at function generation logical circuit top is a binary sequence generator circuit, B _{I, Q}(X) represent Q output constantly.It is got by the nonlinear transformation of the state process logical conversion modular circuit of the mapping function variable store storage in this moment.Logic conversion circuit 1 is carried out the circuit function of non-linear logical conversion to logic conversion circuit n.Fig. 2 and Fig. 4 merge the overall simplified structure of circuit and can represent with Fig. 3.Among Fig. 4, top linear shift register is used for producing m-sequence (practical application also can produce 2 relevant metasequences with additive method, as long as think that the cycle meets the requirements), and its exponent number is S (s preferably is not less than n here).The mapping function variable store then is used for storing the state in a certain moment, is used for for the logical circuit of different numberings it being carried out non-linear logical mappings, thereby produces new function

B (X)=[B _{1, Q}(X), B _{2, Q}(X), B _{3, Q}(X) ..., B _{N, Q}(X)], B here _{I, Q}(x) ∈ (0,1). be located at q constantly, the state that the m-sequence among the figure-1 generates wherein is Vq=[a _q, a _Q+1, a _Q+2..., a _Q+n-1] state of B (X) function correspondence is B _Q(X)=[B _{1, Q}(X), B _{2, Q}(X), B _{3, Q}(X) ..., B _{N, Q}(X)] then the control word of the generation frequency hopping pattern that is assigned with of a certain frequency hopping platform of frequency hopping network of this moment is K _QE=V _q B _Q(X)

=[a _q+ E _n B _{0, Q}, a _Q+En+1 B _{1, Q}, a _Q+En+2 B _{2, Q}..., a _Q+E2n-1 B _{N-1, Q}] and the frequency hopping pattern of another one frequency hopping platform hypothesis is K _QM=V _q B _Q(X)=[a _Q+Mn B _{0, Q}, a _Q+Mn+1 B _{1, Q, aq+2} B _{2, Q}..., a _Q+M2n-1 B _{N-1, Q}]

Here, E and M can for (1,2.。。, 2 ⁿ-1) any one number in has been represented the phase difference between the m-sequence state,

But | E-M|/n=R, requiring R is non-vanishing integer.Appropriate design R can guarantee in the frequency hopping network, and the frequency hopping frequency in each radio station is can occurrence frequency not overlapping or be the state of frequency collision.

Claims (3)

1, a kind of frequency hopping pattern production method of frequency hopping communications networks is characterized in that: comprise n level m sequence generator unit, binary sequence generation unit, vector mapping transformation unit and frequency hopping commands for controlling word cell; The signal that binary sequence generator unit produces is by after non-linear converter's conversion, enter vector mapping transformation unit, after carrying out vector mapping with the m sequence, changed original m sequence hopping rule, become the function set that obtains after the Nonlinear Mapping, each function in this set can be as the frequency control word of the frequency hopping pattern of a frequency hopping communications network, thereby produces the frequency hopping pattern after the mapping, form new frequency hopping control word, constitute frequency hopping commands for controlling word cell.

2, the frequency hopping pattern production method of frequency hopping communications networks according to claim 1 is characterized in that: vector mapping transformation unit is by binary pseudo-random sequence generator and corresponding linear displacement device, and nonlinear combination logic module and mould 2 add the logic device and form.

3, the binary sequence generator in the frequency hopping pattern of frequency hopping communications networks according to claim 2 is characterized in that: pseudo-random sequence generator is the generation circuit of the sequence of m sequence or M sequence or Gold sequence or additive method generation.

Images