CN105357677B - The efficient communication method of multiple antennas is utilized in a kind of system for cognitive radio - Google Patents
The efficient communication method of multiple antennas is utilized in a kind of system for cognitive radio Download PDFInfo
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- CN105357677B CN105357677B CN201510938369.1A CN201510938369A CN105357677B CN 105357677 B CN105357677 B CN 105357677B CN 201510938369 A CN201510938369 A CN 201510938369A CN 105357677 B CN105357677 B CN 105357677B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
- H04W16/14—Spectrum sharing arrangements between different networks
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
- H04B7/0617—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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Abstract
The present invention proposes a kind of efficient communication method that multiple antennas is utilized in system for cognitive radio, including the following steps: perception user determines authorized user orientation using multiple antennas;The signal intelligence of authorized user is judged in authorized user orientation;Communication user is treated using multiple antennas formation wave beam in the orientation of known user to be communicated to communicate.This method further includes the formation null point in the orientation of authorized user, reduces the interference to authorized user.This method further includes that the power of adjustment transmitting reduces interference to other users while guaranteeing reliable communication.The efficient communication method of multiple antennas is utilized in system for cognitive radio proposed by the present invention, can effectively utilize the communication quality of frequency spectrum resource and raising perception user.
Description
Technical field
The present invention relates to communication and field of signal processing, and multiple antennas is utilized in particular to a kind of system for cognitive radio
Efficient communication method.
Background technique
Cognitive radio technology is a kind of technology for the effective use frequency spectrum resource that have developed rapidly in recent years, in cognition wireless
Authorized user obtains the legal right to use to a certain frequency spectrum in electricity, but authorized user is not to provide using the frequency spectrum always
Source is perceived user and can detecte to free time and other users and led to using the frequency spectrum resource when authorized user's free time
Letter, can thus make the available sufficient utilization of the frequency spectrum of authorized user.
The frequency spectrum detection method based on energy, the detection method based on Cyclic Spectrum are provided in the prior art and are based on
Anderson-Darling detection method, the basic principle of these methods are all using the information that measures of perception user from parameter or frequency
The characteristic of spectrum set out determines authorized user whether using authorization frequency spectrum, if the free time perceive user can and other
It is communicated between user.And it to carry out such judgement and just need to handle a large amount of data, algorithm opposite complex calculation time
It is longer;And this method there are one limitation be exactly can only be perceived when authorized user's free time user could obtain and its
Otherwise the chance of his user's communication can form authorized user and interfere, this is not allowed to.
Perception user uses single antenna in the existing method, perception user can use the frequency spectrum of authorized user into
Row communication needs to complete the detection to authorized user's frequency spectrum, needs the respective algorithms using frequency spectrum perception.And these algorithm comparisons
Calculating that is complicated and needing to carry out the long period.
User is perceived in existing method could be communicated in authorized user using the gap of frequency spectrum, logical in authorized user
Frequency spectrum identical with authorized user is not available during letter, this just causes very big limit to the communication time period of perception user
System and uncertainty.
Other authorized users will necessarily be interfered during perception user's communication, therefore during communication
Consider certain power control strategy, therefore being adjusted so that and use other authorizations repeatedly will be carried out during communication
The interference at family can reduce.
Summary of the invention
The present invention proposes a kind of efficient communication method that multiple antennas is utilized in system for cognitive radio, can effectively utilize
Frequency spectrum resource and the communication quality for improving perception user.
In order to achieve the above object, the present invention proposes the efficient communication side that multiple antennas is utilized in a kind of system for cognitive radio
Method, including the following steps:
It perceives user and determines authorized user orientation using multiple antennas;
The signal intelligence of authorized user is judged in authorized user orientation;
Communication user is treated using multiple antennas formation wave beam in the orientation of known user to be communicated to communicate.
Further, this method further includes the formation null point in the orientation of authorized user, and authorized user is done in reduction
It disturbs.
Further, this method further includes that the power of adjustment transmitting reduces while guaranteeing reliable communication to other users
Interference.
Further, the antenna amount of the perception user is more than or equal to 4.
Further, the multiple antennas of the perception user uses smart antenna.
Further, the perception user determines authorized user orientation with the following method using multiple antennas: signal is incident
Different path length differences is had on each antenna when to multiple antennas, so that received signal there can be different skies on each antenna
Between phase, obtain the above space phase information and carry out spatial processing, to obtain to the azimuth information of incoming signal.
Further, the azimuth information of the incoming signal uses following calculation method:
Assuming that being the even linear array constituted with N number of antenna in sensing user end, the spacing of array element is d, the biography in frequency f
Broadcasting coefficient is k, then when signal is incident on antenna array with the angle θ, since the spacing between antenna is to reception signal meeting on N number of antenna
There is respectively different additive phases, the additive phase on N number of antenna can be write as the form of steering vector:
A=[1 e-jkd sinθ … e-j(N-1)kd sinθ]T,
Then when incident signal is X (t), it is received to signal can indicate are as follows:
Y (t)=a (θ) X (t)+n (t)+J (t),
N (t) therein and J (t) are noise and the interference of receiving end respectively, and perception user can have the frequency spectrum of authorized user
Certain pre-known information, therefore simple way of search can be used when determining the orientation of authorized user, i.e., in receiving end pair
Multiplied by being added after weighing vector, the form of weighing vector is each road signal received" * " therein indicates conjugate operation;Signal r (t) after weighting summation are as follows:
Only work as in the searchWhen, the signal after weighting is exactly the coherent superposition meeting that signal is received on N number of antenna
Maximum value is obtained, it is corresponding at this timeIt is exactly the incidence angle of authorized user to get the incidence angle for arriving signal.
The efficient communication method of multiple antennas is utilized in system for cognitive radio proposed by the present invention, can effectively utilize frequency
Spectrum resource and the communication quality for improving perception user.Sensing user end has used multi-antenna technology in the present invention, utilizes more days
Line technology perception user can measure the azimuth information of authorized user, can be fairly simple judge authorized user whether logical
Letter.And it more importantly perceives user and can use the azimuth information for predicting user to be communicated, and multiple antennas can use with this
Spatial processing ability be user to be communicated form specific wave beam;In a general case, when user to be communicated and authorization use
The dimensional orientation difference at family can also can use the frequency spectrum of authorized user while authorized user communicates and to logical when larger
Credit household communicates, while can form zero point in the orientation of authorized user and interfere to avoid to authorized user.This
Sample can be while efficiently using frequency spectrum resource but also the quality of communication is improved.
Detailed description of the invention
Fig. 1 show the efficient communication method stream that multiple antennas is utilized in the system for cognitive radio of present pre-ferred embodiments
Cheng Tu.
Specific embodiment
A specific embodiment of the invention is provided below in conjunction with attached drawing, but the present invention is not limited to the following embodiments and the accompanying drawings.Root
According to following explanation and claims, advantages and features of the invention will be become apparent from.It should be noted that attached drawing be all made of it is very simple
The form of change and use non-accurate ratio, be only used for conveniently, lucidly aid in illustrating the embodiment of the present invention purpose.
Referring to FIG. 1, Fig. 1, which is shown in the system for cognitive radio of present pre-ferred embodiments, utilizes the efficient of multiple antennas
Communication means flow chart.The efficient communication method of multiple antennas is utilized in system for cognitive radio proposed by the present invention, including following
Step:
Step S100: perception user determines authorized user orientation using multiple antennas;
Step S200: the signal intelligence of authorized user is judged in authorized user orientation;
Step S300: wave beam is formed using multiple antennas in the orientation of known user to be communicated and treats communication user progress
Communication.
The judgement of authorized user can only be entered from the characteristic aspect of frequency spectrum in the case where perceiving only one antenna of user
Hand come judge authorized user whether work and when perception user have multiple antennas in the case where then can use spatial processing technology
Estimate the azimuth information of authorized user.Judgement after the azimuth information for obtaining authorized user to signal in specific frequency spectrum
It can be opposite simple, it is only necessary to determine whether the signal of authorized user;Because the frequency range is only awarded at this time in the orientation
Power user may use, and the algorithm of judgement can be simplified.
Assuming that being provided with N number of antenna in sensing user end, the signal received can be recognized due in far field region
To be plane wave, different path length differences is had on each antenna when plane wave is incident on N number of antenna with θ angle, to connect
The signal of receipts can have different space phases on each antenna.It can be carried out airspace using the phase information in these spaces
Processing, to obtain the estimation to the azimuth information of incoming signal.It can determine that received signal is substantially from azimuth information
Which angle N member antenna array is incident on from, is just sentenced for perception user using the estimation to the orientation for receiving signal
The arrival bearing of authorized user is determined, the spatial processing ability that further can use multiple antennas only believes the reception in the orientation
Number handled to determine whether authorized user is communicating on the frequency spectrum of setting.Obtain authorized user's when estimated
After azimuth information, perception user only can analyze and handle to received signal in authorized user orientation, and be directed to
Specific frequency spectrum, then algorithm can be simplified, only need to simply judge fixed orientation, fixation frequency spectrum on whether there is or not letters
Number, it is greatly lowered the complexity calculated.
Preferred embodiment according to the present invention, this method further include step S400: forming null in the orientation of authorized user
Point reduces the interference to authorized user.Further, this method further includes step S500: adjusting the power of transmitting guarantee can
By reducing the interference to other users while communication.The antenna amount of the perception user is more than or equal to 4, further
, the multiple antennas of the perception user uses smart antenna.
The perception user determines authorized user orientation with the following method using multiple antennas: when signal is incident on multiple antennas
Different path length differences is had on each antenna, so that received signal there can be different space phases on each antenna, is obtained
It takes the above space phase information and carries out spatial processing, to obtain the azimuth information to incoming signal.
Further, the azimuth information of the incoming signal uses following calculation method:
Assuming that being the even linear array constituted with N number of antenna in sensing user end, the spacing of array element is d, the biography in frequency f
Broadcasting coefficient is k, then when signal is incident on antenna array with the angle θ, since the spacing between antenna is to reception signal meeting on N number of antenna
There is respectively different additive phases, the additive phase on N number of antenna can be write as the form of steering vector:
A=[1 e-jkd sinθ … e-j(N-1)kd sinθ]T,
Then when incident signal is X (t), it is received to signal can indicate are as follows:
Y (t)=a (θ) X (t)+n (t)+J (t),
N (t) therein and J (t) are noise and the interference of receiving end respectively.In general perception user can be to authorized user
Frequency spectrum have certain pre-known information, therefore simple way of search can be used when determining the orientation of authorized user, that is, existed
To each road signal received multiplied by being added after weighing vector, the form of weighing vector is for receiving end" * " therein indicates conjugate operation;Signal r (t) after weighting summation are as follows:
Only work as in the searchWhen, the signal after weighting is exactly the coherent superposition meeting that signal is received on N number of antenna
Maximum value is obtained, it is corresponding at this timeIt is exactly the incidence angle of authorized user to get the incidence angle for arriving signal.
After obtaining the azimuth information of authorized user, perception user can use multiple antennas and form wave beam to use to be communicated
Family is communicated, while forming null point to authorized user, and perception user in this way can be communicated with user to be communicated
Authorized user will not be interfered simultaneously.Another benefit for perceiving beam forming when user's communication is even if authorized user
In communications status, perceiving user can be communicated due to that can form specific wave beam without causing to do to authorized user simultaneously
It disturbs.
After being estimated using azimuth information of the multiple antennas of sensing user end to incoming wave, perception user can be
The frequency spectrum service condition of authorized user is estimated and judged on the frequency spectrum of setting, that is, judges whether authorized user is communicating.
And for perception user, due to there is N number of antenna, theoretically N-1 wave beam can be formed in space, then waiting in pre- cicada
Wave beam directly can be formed to the orientation after the azimuth information of communication user, the user to be communicated in the orientation is communicated.
Generally, when the orientation spacing of authorized user and user to be communicated are larger, the wave beam that perception user is formed, which can be distinguished, to be awarded
Weigh user and user to be communicated orientation, so that it may formed in orientation to be communicated specific wave beam communicated without
Interference is generated to authorized user.And in order to reduce the interference to authorized user, there can also be the side in authorized user being directed to
Position forms zero point, the further interference reduced to authorized user.
When perceiving user and having multiple antennas and the communication of user to be communicated can use the beam communication of beam forming
It realizes, can thus concentrate the energy of radio frequency for communicating, and no in other directions or radiation is very low, it can be effective
Interference of the reduction to neighbouring other users.Simultaneously as the effect of beam forming can also reduce transmission power, use is lower
Power level be obtained with good communication quality.
When perceive user N number of antenna some orientation formed wave beam when, be the energy that antenna is radiated in space
It is concentrated and is targeted by some particular orientation, and radiationless in other directions or only relatively weak radiation, therefore feel
Know that user can reduce the intensity of transmitting after beam forming is utilized, reduces transmission power.On the other hand, sensing user end
Beam forming only forms wave beam to specific communication direction, and the radiation in other orientation is relatively weak, therefore as perception user
It is also opposite lower to the interference of the user in other orientation when communication.Perception user beam forming make with use to be communicated
Family not only obtains when communicating compared with high s/n ratio, and is reduced to the interference of other users in whole system.Guaranteeing
While perceiving reliable communication between user and user to be communicated, the power control hair appropriate for reducing perception user can also be passed through
Power is penetrated, that is, ensure that received signal-to-noise ratio again and reduce the interference level to other users in system.
In conclusion only one antenna of sensing user end in existing method, needs to frequency used in authorized user
Spectrum carries out complicated calculating and estimation just can determine that whether authorized user is idle.It can be with when sensing user end has multiple antennas
The azimuth information of authorized user is estimated, and treats communication user and forms specific wave beam, and used having estimated authorization
It can be simpler to the estimation of the frequency spectrum of authorized user after the azimuth information at family.In the case that perception user has multiple antennas, i.e.,
Make authorized user also in the state of communication using multiple antennas spatial processing ability can also be formed wave beam be aligned it is to be communicated
User is communicated without generating biggish interference to authorized user, thus can use phase simultaneously together with authorized user
Same frequency spectrum, makes the utilization rate of frequency spectrum obtain effective raising.In the process that perception user is communicated using beam forming
In can by power control reduce sensing user end transmission power, improve the signal noise ratio level of receiving end;Simultaneously because making
It is that beam communication can be to avoid causing unnecessary interference to closing on other users.
The present invention can estimate the azimuth information of authorized user by the way that multiple antennas is arranged in sensing user end, and right
Orientation to be communicated forms wave beam, can be communicated simultaneously using identical frequency spectrum with authorized user, and good obtaining
The interference to other users are closed on is reduced while communication quality.
Although the present invention has been disclosed as a preferred embodiment, however, it is not to limit the invention.Skill belonging to the present invention
Has usually intellectual in art field, without departing from the spirit and scope of the present invention, when can be used for a variety of modifications and variations.Cause
This, the scope of protection of the present invention is defined by those of the claims.
Claims (5)
1. utilizing the efficient communication method of multiple antennas in a kind of system for cognitive radio, characterized in that it comprises the following steps:
It perceives user and determines authorized user orientation using multiple antennas;
The signal intelligence of authorized user is judged in authorized user orientation;
Communication user is treated using multiple antennas formation wave beam in the orientation of known user to be communicated to communicate;
Wherein, the perception user determines authorized user orientation with the following method using multiple antennas: signal is incident on multiple antennas
When have different path length differences on each antenna, so that received signal can have different space phases on each antenna,
It obtains the above space phase information and carries out spatial processing, to obtain the azimuth information to incoming signal;
The azimuth information of the incoming signal uses following calculation method:
Assuming that being the even linear array constituted with N number of antenna in sensing user end, the spacing of array element is d, the propagation system in frequency f
Number is k, then when signal is incident on antenna array with the angle θ, is had respectively due to the spacing between antenna to signal is received on N number of antenna
From different additive phases, the additive phase on N number of antenna can be write as the form of steering vector:
A=[1 e-jkdsinθ Λ e-j(N-1)kdsinθ]T,
Then when incident signal is X (t), it is received to signal can indicate are as follows:
Y (t)=a (θ) X (t)+n (t)+J (t),
N (t) therein and J (t) are noise and the interference of receiving end respectively, and perception user can have centainly the frequency spectrum of authorized user
Pre-known information, therefore determine authorized user orientation when can use simple way of search, i.e., in receiving end to reception
To each road signal multiplied by being added after weighing vector, the form of weighing vector is
" * " therein indicates conjugate operation;Signal r (t) after weighting summation are as follows:
Only work as in the searchWhen, the signal after weighting is exactly that the coherent superposition of reception signal on N number of antenna can obtain
Maximum value, it is corresponding at this timeIt is exactly the incidence angle of authorized user to get the incidence angle for arriving signal.
2. utilizing the efficient communication method of multiple antennas in system for cognitive radio according to claim 1, which is characterized in that
This method further includes the formation null point in the orientation of authorized user, reduces the interference to authorized user.
3. utilizing the efficient communication method of multiple antennas in system for cognitive radio according to claim 1, which is characterized in that
This method further includes that the power of adjustment transmitting reduces interference to other users while guaranteeing reliable communication.
4. utilizing the efficient communication method of multiple antennas in system for cognitive radio according to claim 1, which is characterized in that
The antenna amount of the perception user is more than or equal to 4.
5. utilizing the efficient communication method of multiple antennas in system for cognitive radio according to claim 1, which is characterized in that
The multiple antennas of the perception user uses smart antenna.
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CN106452653A (en) * | 2016-11-11 | 2017-02-22 | 上海电机学院 | Method for inhibiting interference of distributed multi-antenna system on macro cellular base station |
CN108235328B (en) * | 2018-01-08 | 2022-03-01 | 中国科学院上海高等研究院 | Automatic spectrum re-sensing method, system, computer readable storage medium and terminal |
Citations (5)
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CN101808334A (en) * | 2010-03-15 | 2010-08-18 | 北京科技大学 | Spectrum perception method for detecting angle of arrival of authorized user in cognitive radio |
CN101969352A (en) * | 2010-11-12 | 2011-02-09 | 北京邮电大学 | Fast variable polarization-based spectrum sensing method |
CN102291186A (en) * | 2011-07-06 | 2011-12-21 | 电子科技大学 | Frequency spectrum perceiving method based on estimation of signal arrival direction |
CN102307356A (en) * | 2011-09-05 | 2012-01-04 | 中国人民解放军国防科学技术大学 | Hierarchical-control-channel-mechanism-based cognitive radio network establishment method |
CN103001684A (en) * | 2012-12-18 | 2013-03-27 | 清华大学 | Robust interference rejection method in multi-antenna cognitive radio communication system |
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CN101808334A (en) * | 2010-03-15 | 2010-08-18 | 北京科技大学 | Spectrum perception method for detecting angle of arrival of authorized user in cognitive radio |
CN101969352A (en) * | 2010-11-12 | 2011-02-09 | 北京邮电大学 | Fast variable polarization-based spectrum sensing method |
CN102291186A (en) * | 2011-07-06 | 2011-12-21 | 电子科技大学 | Frequency spectrum perceiving method based on estimation of signal arrival direction |
CN102307356A (en) * | 2011-09-05 | 2012-01-04 | 中国人民解放军国防科学技术大学 | Hierarchical-control-channel-mechanism-based cognitive radio network establishment method |
CN103001684A (en) * | 2012-12-18 | 2013-03-27 | 清华大学 | Robust interference rejection method in multi-antenna cognitive radio communication system |
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