CN101252406A - Anti-multiaddress interfering direct sequence spread spectrum communication system - Google Patents

Abstract

Disclosed is a direct sequence spread spectrum communication system which resists the multiple access interference and relates to the direct sequence spread spectrum wireless communication field, aiming at solving the problems that the multiple access interference is high and the new user can not receive the correct information. A multiple access interference computation module (11) is added to the transmitter of the direct sequence spread spectrum communication system in the prior art for figuring out the initial phase value; the computed initial phase value is transmitted to a first initial phase generator (12); the first initial phase generator (12) is used for generating the initial phase, receiving the initial phase parameter computed by the multiple access interference computation module (11) and sending the initial parameter to a first carrier generator (13); a second initial phase generator (17) is added to the receiver of the direct sequence spread spectrum communication system in the prior art for generating the initial phase parameter the same as the initial phase parameter generated by the first initial phase generator in the transmitter and sending the initial phase parameter to a second carrier generator (18). Compared with the direct sequence spread spectrum communication in the prior art, the direct sequence spread spectrum communication system which resists the multiple access interference improves the system capacity; the implementation method is simple and effective.

Description

The direct sequence spread spectrum communication system that anti-multiple access disturbs

Technical field

The present invention relates to the direct sequence spread spectrum wireless communication field, the multiple access interference not improve existing user that is specifically related in the direct sequence spread spectrum communication is a prerequisite, is reduced in the device of the multiple access interference of other base station range overlapping region Nei Xinjia access customers.

Background technology

The spread spectrum communication system transmitting terminal will be to be transmitted information data through pseudorandomcode (frequency expansion sequence) modulation, realize transmission again after the spread spectrum, receiving terminal then adopts same coding to separate the mediation relevant treatment, recovers original information data.This communication mode is opposite with general common narrow band communication mode, be spread-spectrum after, broadband connections, relevant treatment reverts to demodulating data behind the arrowband again, therefore, has pseudorandomcode modulation and signal correction processing two big characteristics.These two big characteristics make the spread spectrum communication mode that many advantages be arranged, as anti-interference, anti-multipath decline, multiple access multiplexing, low power spectral density etc. just.The most direct application of spread spectrum technic is the cdma communication technology, and the cdma communication technology is the CDMA communication technology.All users transmit simultaneously, each user uses frequency expansion sequence separately, these frequency expansion sequences are quadratures or near quadrature, frequency expansion sequence between each user influences each other very little, can be in same extremely wide apread spectrum bandwidth, each user sends and received signal simultaneously without interfering with each other, realizes multiple access communication.But in the reality because employed frequency expansion sequence of each user and incomplete quadrature, and because the system that influences of various interference is difficult to guarantee very high synchronization accuracy, this has reduced the orthogonality of each user's frequency expansion sequence to a certain extent, even some the time also can produce bigger cross-correlation peak value, cause inter-user interference.Along with the development of mobile communication cause, mobile communication system need provide service for increasing user, and inter-user interference (multiple access interference) problem becomes outstanding all the more.In cdma system, in the overlapping region of adjacent three base stations (as Fig. 1) coverage, may take place because multiple access disturbs very high, total interference value that system is subjected to exceeds jamming margin, initiate user can't receive correct information, the base station can't provide the situation of service again for new user, reduce multiple access by further raising system clock synchronization accuracy this moment and disturb the increase that obtains power system capacity very difficult beyond doubt.

Summary of the invention

The present invention increases new user in order to solve in the base station range overlapping region, and take place because multiple access disturbs very high, total interference value that system is subjected to exceeds jamming margin, initiate user can't receive the problem of correct information, and has proposed the direct sequence spread spectrum communication system that anti-multiple access disturbs.

The transmitter of the direct sequence spread spectrum communication system that anti-multiple access disturbs, it comprises as the lower part:

Serial/parallel transducer 1 is used for original information data is divided into I, Q two paths of signals, and two paths of signals is sent to first frequency multiplier 6 and second frequency multiplier 7 respectively;

First frequency multiplier 6 and second frequency multiplier 7 are used for I, Q two paths of signals are carried out spread spectrum respectively, and send to the first binary system frequency modulator 8 and the second binary system frequency modulator 10 respectively;

First pseudo-noise code generator 2 and second pseudo-noise code generator 3 are used to produce different pseudo-random code sequences, send to first frequency multiplier 6 and second frequency multiplier 7;

First carrier generator 13 is used to produce the two-way carrier signal, sends to respectively in the first binary system frequency modulator 8 and first pi/2 phase shifter 9;

First pi/2 phase shifter 9 is used for the carrier signal that first carrier generator 13 is produced is offset, and sends in the second binary system frequency modulator 10;

The first binary system frequency modulator 8 and the second binary system frequency modulator 10, be used to modulate I, Q two paths of signals behind the spread spectrum, respectively the I behind the spread spectrum, Q two paths of signals are modulated by the two-way carrier signal that receives, frequency spectrum shift to high band, is sent in the adder 4;

Adder 4 is used for the first binary system frequency modulator 8 and the second binary system frequency modulator, 10 modulated I, Q two paths of signals are superposeed, and sends to wide-band amplifier 5;

Wide-band amplifier 5 is used for the signal after adder 4 stacks being amplified and launching by transmitting antenna;

It also comprises the multiple access interference calculation module 11 and the first initial phase generator 12;

Multiple access interference calculation module 11 is used to calculate the initial phase place value; And the initial phase place value after will calculating sends to the first initial phase generator 12;

The first initial phase generator 12 is used to produce initial phase, accepts the initial phase parameter that calculates of multiple access interference calculation module 11 and sends to first carrier generator 13, the two-way carrier wave cos2 π f that this locality in the first carrier generator 13 is produced _cT and sin2 π f _cT is adjusted into cos (2 π f _cT+ φ) and sin (2 π f _cT+ φ).

The receiver of the direct sequence spread spectrum communication system that anti-multiple access disturbs, it comprises with the lower part:

Power divider 14, the signal allocation that is used for reception that reception antenna is obtained is I, Q two paths of signals, and the signal that distributes is sent to the first binary system frequency demodulator 15 and the second binary system frequency demodulator 16 respectively;

The first binary system frequency demodulator 15 and the second binary system frequency demodulator 16, the I, the Q two-way high-frequency signal that are used for receiving carry out demodulation by the carrier signal that is loaded with the initial phase parameter respectively, and send to first despreader 22 and second despreader 23;

Second carrier generator 18 is used to produce the carrier signal that has the initial phase parameter, signal is divided into two-way sends to the first binary system frequency demodulator 15 and second pi/2 phase shifter 19 respectively;

Second pi/2 phase shifter 19 is used for the carrier signal that second carrier generator 18 is produced is offset, and sends in the second binary system frequency demodulator 16;

First despreader 22 and second despreader 23 are used for the two paths of signals after the demodulation is carried out despreading by the 3rd pseudo-noise code generator 20 and the 4th pseudo-noise code generator 21 respectively, and send to first baseband filter 24 and second baseband filter 25;

The 3rd pseudo-noise code generator 20 and the 4th pseudo-noise code generator 21 are used to produce the different pseudo-random code sequence of the two-way identical with emitter, send to first despreader 22 and second despreader 23;

First baseband filter 24 and second baseband filter 25 are used for the two paths of signals filtering radio-frequency component after the demodulation, and send to first integrator 26 and second integral device 27;

First integrator 26 and second integral device 27 are used for the two paths of signals behind baseband filtering is carried out integral and calculating, and send to parallel/serial transducer 29;

Parallel/serial transducer 29, being used for I, Q two paths of signals behind first integrator 26 and second integral device 27 quadrature conversions are carried out serial is original data signal;

It also comprises the second initial phase generator 17;

The second initial phase generator 17 is used for producing the initial phase parameter identical with the first initial phase generator of emitter, and sends to second carrier generator 18.

The present invention adds initial phase in original direct sequence spread spectrum communication system, make the local two-way carrier wave cos2 π f that produces _cT and sin2 π f _cT is adjusted into cos (2 π f _cT+ φ) and sin (2 π f _cT+ φ), f wherein _cBe carrier frequency.At transmitting terminal, raw information is divided into I, Q two paths of signals through serial/parallel transducer, utilizes different pseudo noise codes that I, Q two paths of signals are carried out spread spectrum, more respectively through two-way carrier wave cos (2 π f _cT+ φ) and sin (2 π f _cT+ φ) modulation, to high band, modulated I, the information addition of Q two-way are gone out by transmission antennas transmit after wide-band amplifier amplifies again frequency spectrum shift; At receiving terminal, the I that the respective user handle receives, Q two paths of signals are respectively through cos (2 π f _cT+ φ) and sin (2 π f _cT+ φ) demodulation, and the use pseudo noise code identical with transmitting terminal carry out despreading to information, can get original data signal through baseband filter, integration decision device again.The present invention is by adjusting the carrier wave initial phase of adjacent three base stations on the spread spectrum system down link, disturbing with the multiple access that does not improve existing user is prerequisite, the multiple access that is reduced in other base station range overlapping region Nei Xinjia access customers disturbs, and makes newly to add access customer and can communicate with the base station.The beneficial effect of this method is, can improve power system capacity on original direct-sequence communications system basis, realizes effectively simple with the method that obtains power system capacity by further raising system clock synchronization accuracy and increase.

Description of drawings

Fig. 1 a is the structural representation of the direct sequence spread spectrum communication system transmitting terminal of anti-multiple access interference of the present invention; Fig. 1 b is the structural representation of the direct sequence spread spectrum communication system receiving terminal of anti-multiple access interference of the present invention; Fig. 2 is adjacent three base station ranges and relative users position view.

Embodiment

Embodiment one: in conjunction with Fig. 1 a and Fig. 1 b explanation present embodiment, the transmitter of the direct sequence spread spectrum communication system that the anti-multiple access of present embodiment disturbs is by forming with the lower part:

Serial/parallel transducer 1 is used for original information data is divided into I, Q two paths of signals, and two paths of signals is sent to first frequency multiplier 6 and second frequency multiplier 7 respectively;

First frequency multiplier 6 and second frequency multiplier 7 are used for I, Q two paths of signals are carried out spread spectrum respectively, and send to the first binary system frequency modulator 8 and the second binary system frequency modulator 10 respectively;

First pseudo-noise code generator 2 and second pseudo-noise code generator 3 are used to produce different pseudo-random code sequences, send to first frequency multiplier 6 and second frequency multiplier 7;

Multiple access interference calculation module 11 is used to calculate the initial phase place value; And the initial phase place value after will calculating sends to the first initial phase generator 12;

The first initial phase generator 12 is used to produce initial phase, accepts multiple access and interferes the initial phase parameter that calculates of computing module 11 and send to first carrier generator 13, the two-way carrier wave cos2 π f that this locality in the first carrier generator 13 is produced _cT and sin2 π f _cT is adjusted into cos (2 π f _cT+ φ) and sin (2 π f _cT+ φ);

First carrier generator 13 is used to produce the two-way carrier signal, sends to respectively in the first binary system frequency modulator 8 and first pi/2 phase shifter 9;

First pi/2 phase shifter 9 is used for the carrier signal that first carrier generator 13 is produced is offset, and sends in the second binary system frequency modulator 10;

The first binary system frequency modulator 8 and the second binary system frequency modulator 10, be used to modulate I, Q two paths of signals behind the spread spectrum, respectively the I behind the spread spectrum, Q two paths of signals are modulated by the two-way carrier signal that receives, frequency spectrum shift to high band, is sent in the adder 4;

Adder 4 is used for the first binary system frequency modulator 8 and the second binary system frequency modulator, 10 modulated I, Q two paths of signals are superposeed, and sends to wide-band amplifier 5;

Wide-band amplifier 5 is used for the signal after adder 4 stacks being amplified and launching by transmitting antenna.

The receiver of the direct sequence spread spectrum communication system that anti-multiple access disturbs is by forming with the lower part:

Power divider 14, the signal allocation that is used for reception that reception antenna is obtained is I, Q two paths of signals, and the signal that distributes is sent to the first binary system frequency demodulator 15 and the second binary system frequency demodulator 16 respectively;

The first binary system frequency demodulator 15 and the second binary system frequency demodulator 16, the I, the Q two-way high-frequency signal that are used for receiving carry out demodulation by the carrier signal that is loaded with the initial phase parameter respectively, and send to first despreader 22 and second despreader 23;

The second initial phase generator 17 is used for producing the initial phase parameter identical with the first initial phase generator of emitter, and sends to second carrier generator 18;

Second carrier generator 18 is used to produce the carrier signal that has the initial phase parameter, signal is divided into two-way sends to the first binary system frequency demodulator 15 and second pi/2 phase shifter 19 respectively;

Second pi/2 phase shifter 19 is used for the carrier signal that second carrier generator 18 is produced is offset, and sends in the second binary system frequency demodulator 16;

First despreader 22 and second despreader 23 are used for the two paths of signals after the demodulation is carried out despreading by the 3rd pseudo-noise code generator 20 and the 4th pseudo-noise code generator 21 respectively, and send to first baseband filter 24 and second baseband filter 25;

The 3rd pseudo-noise code generator 20 and the 4th pseudo-noise code generator 21 are used to produce the different pseudo-random code sequence of the two-way identical with emitter, send to first frequency multiplier 6 and second frequency multiplier 7;

First baseband filter 24 and second baseband filter 25 are used for the two paths of signals filtering radio-frequency component after the demodulation, and send to first integrator 26 and second integral device 27;

First integrator 26 and second integral device 27 are used for the two paths of signals behind baseband filtering is carried out integral and calculating, and send to parallel/serial transducer 29;

Parallel/serial transducer 29 is used for I, Q two paths of signals behind first integrator 26 and second integral device 27 quadrature conversions are superposed to original data signal.

Embodiment two: present embodiment is described in conjunction with Fig. 1 a, Fig. 1 b and Fig. 2, present embodiment is for supposing at A, B, C three base station range overlapping regions original three user A1, B1, C1, user A1, B1, C1 respectively with A, B, C three base station communications, add access customer A2 this moment, and A2 and A base station communicate.Be calculated as follows by multiple access interference calculation module 11:

Base station A to the signal of user A1 emission is:

S _A1(t)＝S _A1I(t)+S _A1Q(t)

Wherein

S _A1I(t)＝A ₁d _A1I(t-τ _A1I)PN _A1I(t-τ _A1I)cos(2πf _ct+φ _A1)

S _A1Q(t)＝A ₁d _A1Q(t-τ _A1Q)PN _A1Q(t-τ _A1Q)sin(2πf _ct+φ _A1)

S in the described formula _A1I(t) be A1 user I road signal, S _A1Q(t) be A1 user Q road signal, A ₁Be amplitude, d _A1I(t-τ _A1I) be I road information data, d _A1Q(t-τ _A1Q) be Q road information data, PN _A1I(t-τ _A1I) be I road spreading code, PN _A1Q(t-τ _A1Q) be Q road spreading code, φ _A1Be A1 user's initial phase, τ _A1I, τ _A1QBe respectively I, the time-delay of Q two paths of data.

Can think that in A, B, C three base station range overlapping regions each subscriber signal amplitude equates, all value is 1 herein, and when thinking that there is precise synchronization in system, can think that the information data time-delay is 0, i.e. A ₁=1, τ _A1I=τ _A1Q=0.

Then base station A is rewritten as the signal of user A1 emission:

S _A1(t)＝d _A1I(t)PN _A1I(t)cos(2πf _ct+φ _A1)+d _A1Q(t)PN _A1Q(t)sin(2πf _ct+φ _A1)

User A1 is to newly adding the interference of access customer A2, and the A1 signal receives through the A2 receiver, is output as after A2 end and local I road carrier wave and spreading code multiply each other:

$V_{A1A2I}\left(t\right)={\∫}_0^T{d}_{A1I}\left(t\right){\mathrm{PN}}_{A1I}\left(t\right)\cos (2\mathrm{\π}{f}_{c}t+{\mathrm{\φ}}_{A1})\·2{\mathrm{PN}}_{A2I}\left(t\right)\cos (2\mathrm{\π}{f}_{c}t+{\mathrm{\φ}}_{A2})\mathrm{dt}$

$+{\∫}_0^T{d}_{A1Q}\left(t\right){\mathrm{PN}}_{A1Q}\left(t\right)\sin (2\mathrm{\π}{f}_{c}t+{\mathrm{\φ}}_{A1})\·2{\mathrm{PN}}_{A2I}\left(t\right)\cos (2\mathrm{\π}{f}_{c}t+{\mathrm{\φ}}_{A2})\mathrm{dt}$

Behind baseband filter filtering radio-frequency component, integrator is output as:

$V_{A1A2I}\left(t\right)={\∫}_0^T(d_{A1I}\left(t\right){\mathrm{PN}}_{A1I}\left(t\right){\mathrm{PN}}_{A2I}\left(t\right)\cos ({\mathrm{\φ}}_{A1}-{\mathrm{\φ}}_{A2})+d_{A1Q}\left(t\right){\mathrm{PN}}_{A1Q}\left(t\right){\mathrm{PN}}_{A2I}\left(t\right)\sin ({\mathrm{\φ}}_{A1}-{\mathrm{\φ}}_{A2}))\mathrm{dt}$

Order $R_{A1\mathrm{IA}2I}={\∫}_0^T{\mathrm{PN}}_{A1I}\left(t\right){\mathrm{PN}}_{A2I}\left(t\right)\mathrm{dt},R_{A1\mathrm{QA}2I}={\∫}_0^T{\mathrm{PN}}_{A1Q}\left(t\right){\mathrm{PN}}_{A2I}\left(t\right)\mathrm{dt}$

Then, user A1 to the interference value of the I road received signal of A2 is

V _A1A2I＝d _A1IR _A1IA2Icos(φ _A1-φ _A2)+d _A1QR _A1QA2Isin(φ _A1-φ _A2)

In like manner can get the Q road reception interference value of user A1 to A2

V _A1A2Q＝d _A1IR _A1IA2Qsin(φ _A2-φ _A1)+d _A1QR _A1QA2Qcos(φ _A-φ _A2)

In like manner can get user B1, C1 I, Q two-way interference value V to A2 _B1A2I, V _B1A2Q, V _C1A2I, V _C1A2Q, then A1, B1, C1 three users are to I road total multiple access interference value M of A2 _A2I, Q road total multiple access interference level value M _A2QFor,

M _A2I＝V _A1A2I+V _B1A2I+V _C1A2I，M _A2Q＝V _A1A2Q+V _B1A2Q+V _C1A2Q

Suppose under the situation that does not have initial phase to adjust, i.e. φ _A1=φ _A2=0, user A1 is d to the I road reception interference level value of A2 _A1IR _A1IA2I, make J _A2IFor A1, B1, C1 three users to the total multiple access interference level value in the I road of A2, then J _A2I=d _A1IR _A1IA2I+ d _B1IR _B1IA2I+ d _C1IR _C1IA2I, in like manner, make J _A2QFor A1, B1, C1 three users to the total multiple access interference level value in the Q road of A2, J _A2Q=d _A1QR _A1QA2Q+ d _B1QR _B1QA2Q+ d _C1QR _C1QA2QThe original carrier phase place of adjusting existing user is exactly to make the suffered multiple access that newly adds access customer A2 disturb total value less than the interference value before adjusting, and promptly will reach | M _A2I|+| M _A2Q|≤| J _A2I|+| J _A2Q|.Define I, the Q two-way multiple access interference value addition again that takes absolute value herein, the value that obtains is disturbed total value for the suffered multiple access of user.

But after adding the adjustment of new user A2 and original subscriber's carrier wave initial phase, need make the multiple access of original subscriber A1, B1, C1 disturb total value not increase.Supposed that before not adding new user A2 the multiple access that user A1 only is subjected to user B1, C1 disturbs, it is J that the I road receives interference level value _A1I=d _B1IR _B1IA1I+ d _C1IR _C1IA1I, it is J that the Q road receives interference level value _A1Q=d _B1QR _B1QA1Q+ d _C1QR _C1QA1Q, in like manner can not add before new user A2 and phase place adjust the I of user B1, C1, Q two-way multiple access interference level value.Comprehensive above two conditions after adding the adjustment of new user A2 and phase place, should make the multiple access of original subscriber A1, B1, C1 disturb total value not increase, and make the suffered multiple access that newly adds access customer A2 disturb total value less than the interference value before adjusting, φ again _A1, φ _B1, φ _C1Value need satisfy with the lower inequality group and (for convenience of explanation, get φ _A2=0, then adjust φ _A1, φ _B1, φ _C1Value get final product, below identical)

$\left\{\begin{array}{c}\left|M_{A1I}\right|+\left|M_{A1Q}\right|\≤\left|J_{A1I}\right|+\left|J_{A1Q}\right|\\ \left|M_{B1I}\right|+\left|M_{B1Q}\right|\≤\left|J_{B1I}\right|+\left|J_{B1Q}\right|\\ \left|M_{C1I}\right|+\left|M_{C1Q}\right|\≤\left|J_{C1I}\right|+\left|J_{C1Q}\right|\\ \left|M_{A2I}\right|+\left|M_{A2Q}\right|\≤\left|J_{A2I}\right|+\left|J_{A2Q}\right|\end{array}\right.$

At the corresponding adding initial phase of transmitting terminal adjusting module, by calculating the φ that obtains to satisfy with the upper inequality group with receiving terminal _A1, φ _B1, φ _C1, and seek | M _A2I|+| M _A2Q| minimum value, get the φ that obtain this moment _A1, φ _B1, φ _C1Initial phase place value as three user A1, B1, C1, then adding new user A2 and adjusting under the situation of a plurality of user's initial phases, the multiple access of original subscriber A1, B1, C1 disturbs total value not increase, and the multiple access of new user A2 disturbs total value than little before adjusting phase place, and gets possible minimum value.Under existing higher synchronization accuracy of system and the very difficult situation that continues to improve,, reach the effect that increases power system capacity by adjusting each subscribers carrier initial phase.

The cycle of selecting for use during simulating, verifying be 127 m sequence as frequency expansion sequence, the m sequence generator polynomial that A1 user I, Q two-way use is respectively X ⁷+ X ⁴+ X ³+ X ²+ 1, X ⁷+ X ⁶+ X ⁵+ X ⁴+ X ²+ X+1, the m sequence generator polynomial that B1 user I, Q two-way use is respectively X ⁷+ X ⁵+ X ⁴+ X ³+ X ²+ X+1, X ⁷+ X ⁶+ X ⁴+ X ²+ 1, the m sequence generator polynomial that C1 user I, Q two-way use is respectively X ⁷+ X+1, X ⁷+ X ⁶+ X ³+ X+1, the m sequence generator polynomial that A2 user I, Q two-way use is respectively X ⁷+ X ³+ X ²+ X+1, X ⁷+ X ⁶+ X ⁵+ X ²+ 1, initial phase φ before not adjusting _A1, φ _B1, φ _C1All get 0, institute's transfer information data all gets 1.Increase each user's phase value successively from 0 to 2pi, calculate to adopt the multiple access interference value between the user behind the current phase value again, if satisfying the inequality group that proposes just keeps earlier, do not satisfy and just abandon this class value, and then continue to adjust, after all possible phase place traveled through, in the many groups phase value that has obtained, pick out and improve best one group of effect as final initial phase place value.According to calculating, optimum initial phase place value is ${\mathrm{\φ}}_{A1}=\frac{11}{8}\mathrm{\π},$ ${\mathrm{\φ}}_{B1}=\frac{3}{2}\mathrm{\π},$ ${\mathrm{\φ}}_{C1}=\frac{3}{4}\mathrm{\π},$ Each user's multiple access disturbed condition improves result such as following table, can see under the situation that adds access customer A2, and by adjusting each subscribers carrier initial phase, each user's multiple access disturbs all reduction.

Table 1 original subscriber multiple access disturbs and improves information slip

Table 2 newly adds access customer A2 multiple access disturbed condition improvement table

Other composition is identical with embodiment one with connected mode.

Claims (3)

1, the transmitter of the direct sequence spread spectrum communication system of anti-multiple access interference, it comprises as the lower part:

Serial/parallel transducer (1) is used for original information data is divided into I, Q two paths of signals, and two paths of signals is sent to first frequency multiplier (6) and second frequency multiplier (7) respectively;

First frequency multiplier (6) and second frequency multiplier (7) are used for I, Q two paths of signals are carried out spread spectrum respectively, and send to the first binary system frequency modulator (8) and the second binary system frequency modulator (10) respectively;

First pseudo-noise code generator (2) and second pseudo-noise code generator (3) are used to produce different pseudo-random code sequences, send to first frequency multiplier (6) and second frequency multiplier (7);

First carrier generator (13) is used to produce the two-way carrier signal, sends to respectively in the first binary system frequency modulator (8) and first pi/2 phase shifter (9);

First pi/2 phase shifter (9) is used for the carrier signal that first carrier generator (13) is produced is offset, and sends in the second binary system frequency modulator (10);

The first binary system frequency modulator (8) and the second binary system frequency modulator (10), be used to modulate I, Q two paths of signals behind the spread spectrum, respectively the I behind the spread spectrum, Q two paths of signals are modulated by the two-way carrier signal that receives, frequency spectrum shift to high band, is sent in the adder (4);

Adder (4) is used for the first binary system frequency modulator (8) and second binary system frequency modulator (10) modulated I, Q two paths of signals are superposeed, and sends to wide-band amplifier (5);

Wide-band amplifier (5) is used for the signal after adder (4) stack being amplified and launching by transmitting antenna;

It is characterized in that it also comprises the multiple access interference calculation module (11) and the first initial phase generator (12);

Multiple access interference calculation module (11) is used to calculate final initial phase place value; And the initial phase place value after will calculating sends to the first initial phase generator (12);

The first initial phase generator (12), be used to produce initial phase, accept the initial phase parameter that calculates of multiple access interference calculation module (11) and send to first carrier generator (13), the two-way carrier wave cos2 π f that this locality in the first carrier generator (13) is produced _cT and sin2 π f _cT is adjusted into cos (2 π f _cT+ φ) and sin (2 π f _cT+ φ).

2, the transmitter of the direct sequence spread spectrum communication system that anti-multiple access according to claim 1 disturbs, it is characterized in that multiple access interference calculation module (11), be used to calculate and increase each user's phase value successively from 0 to 2pi, calculate to adopt the multiple access interference value between the user behind the current phase value again, if existing user's original carrier phase place is exactly to make the suffered multiple access that newly adds access customer A2 disturb total value less than the interference value before adjusting, just satisfy and keep earlier, do not satisfy and just abandon this class value, and then continue to adjust, after all phase places have been traveled through, in the many groups phase value that has obtained, judge the highest one group of improvement degree as the final initial phase place value that sends.

3, the receiver of the direct sequence spread spectrum communication system of anti-multiple access interference, it comprises with the lower part:

Power divider (14), the signal allocation that is used for reception that reception antenna is obtained is I, Q two paths of signals, and the signal that distributes is sent to the first binary system frequency demodulator (15) and the second binary system frequency demodulator (16) respectively;

The first binary system frequency demodulator (15) and the second binary system frequency demodulator (16), the I, the Q two-way high-frequency signal that are used for receiving carry out demodulation by the carrier signal that is loaded with the initial phase parameter respectively, and send to first despreader (22) and second despreader (23);

Second carrier generator (18) is used to produce the carrier signal that has the initial phase parameter, signal is divided into two-way sends to the first binary system frequency demodulator (15) and second pi/2 phase shifter (19) respectively;

Second pi/2 phase shifter (19) is used for the carrier signal that second carrier generator (18) is produced is offset, and sends in the second binary system frequency demodulator (16);

First despreader (22) and second despreader (23), be used for the two paths of signals after the demodulation is carried out despreading by the 3rd pseudo-noise code generator (20) and the 4th pseudo-noise code generator (21) respectively, and send to first baseband filter (24) and second baseband filter (25);

The 3rd pseudo-noise code generator (20) and the 4th pseudo-noise code generator (21) are used to produce the different pseudo-random code sequence of the two-way identical with emitter, send to first frequency multiplier (6) and second frequency multiplier (7);

First baseband filter (24) and second baseband filter (25) are used for the two paths of signals filtering radio-frequency component after the demodulation, and send to first integrator (26) and second integral device (27);

First integrator (26) and second integral device (27) are used for the two paths of signals behind baseband filtering is carried out integral and calculating, and send to parallel/serial transducer (29);

Parallel/serial transducer (29) is used for I, Q two paths of signals behind first integrator (26) and second integral device (27) quadrature conversion are superposed to original data signal;

It is characterized in that it also comprises the second initial phase generator (17);

The second initial phase generator (17) is used for producing the initial phase parameter identical with the first initial phase generator of emitter, and sends to second carrier generator (18).

Images