CN103533550A

CN103533550A - Frequency-point selection method and device in cognitive radio system

Info

Publication number: CN103533550A
Application number: CN201210233104.8A
Authority: CN
Inventors: 蒋成钢; 唐业明; 白文岭; 李媛媛; 杨宇
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT
Priority date: 2012-07-06
Filing date: 2012-07-06
Publication date: 2014-01-22

Abstract

The embodiment of the invention discloses a frequency-point selection method and device in a cognitive radio system. A technical scheme of the embodiment of the invention is applied so that a base station carries out wireless communication and at the same time, obtains quality indications of current communication links and selects a new work frequency point according to current idle spectrum resource information and corresponding quality indications when frequency point adjustment processing is triggered and continues to carry out wireless communication on the new work frequency point. Therefore, a spectrum dynamic use capability of the cognitive radio system is used to select spectrums flexibly according to the communication quality of a current work frequency point itself and particularly, when the communication quality of a current work frequency band cannot meet communication quality demands of the cognitive radio, the device is readjusted to other usable frequency points to work until a frequency point, communication quality demands of which are met, is found. Therefore, it is ensured that the work frequency point can meet communication quality demands of the system from beginning to end and thus communication quality of a network is improved and reliability of system communication is strengthened.

Description

Frequency point selecting method in cognitive radio system and equipment

Technical field

The present invention relates to communication technical field, particularly frequency point selecting method and the equipment in a kind of cognitive radio system.

Background technology

Development fast along with mobile communication cause, growing broadband wireless communications demand and the contradiction of limited frequency spectrum resource become clear day by day, although at LTE(Long Term Evolution, Long Term Evolution) adopted OFDM(Orthogonal Frequency Division Multiplexing, OFDM), MIMO(Multiple Input Multiple Output, multiple-input, multiple-output) etc. technology improves the availability of frequency spectrum, but these can not fundamentally solve the problem of limited frequency spectrum resource.

Along with mobile service is in development at full speed in future, telecom operators will face the problem of severeer frequency spectrum resource shortage, on the other hand, the frequency spectrum of some wireless systems is used on time and region almost idle, as for radio and television frequency range, along with the development of radio data system from analogue transmission to Digital Transmission, because Digital Transmission can improve transmission capacity greatly, make a lot of radio and television frequency ranges for a long time in idle condition, wasted valuable Radio Resource.And other a lot of wireless systems are also proved to be its frequency spectrum and are underutilized.

For solving frequency spectrum resource problem in short supply, new radiotechnics---cognitive radio (Cognitive Radio, CR) technology is paid close attention to widely.Cognitive radio technology is a kind of effective means that current frequency spectrum resource is in short supply that solves.Cognitive radio is an intelligent wireless communication system, can sensing external environment, and use artificial intelligence technology from environment learning, by some operating parameter of real-time change (such as through-put power, carrier frequency and modulation technique etc.), the wireless signal statistical property that its internal state adaptation is received changes, reaching any time, any place all can realize height reliable communication, and frequency spectrum resource carried out to the effect effectively utilized.

For reaching above-mentioned object, cognitive radio has encircled whole cognitive process by a cognition, comprises following three steps:

(1) frequency spectrum perception, by input RF(Radio Frequency, radio frequency) analysis of pumping signal, complete the detection to idle frequency spectrum.

(2) spectrum analysis, the analysis according to the result of frequency spectrum perception and other wireless input signal, completes the estimation of channel condition information and the expectation of channel capacity.

(3) frequency spectrum decision-making, the idle frequency spectrum resource obtaining according to frequency spectrum perception and the result of spectrum analysis, obtain the decision-making that last frequency spectrum is used, and this decision-making comprises the decision-making of frequency, bandwidth, transmitting power, modulation system etc.

The frequency spectrum perception of cognitive radio has detected the detection of idle frequency spectrum resource by the binary signal by frequency band, in general sense, can think that frequency spectrum perception technology is exactly a kind of signal detection technique.Frequency spectrum perception need to meet certain perceptual sensitivity requirement, and the authoring system signal power receiving is greater than perceptual sensitivity and requires this signal to be detected, thereby guarantees can not produce harmful interference to authoring system.

This perceptual sensitivity concrete as: FCC(Federal Communications Commission, (U.S.) Federal Communications Committee) regulation is for ATSC(Advanced Television Systems Committee, the U.S. advanced television management consultant committee) detection of TV signal need to reach perceptual sensitivity-114dBm requirement, for NTSC(National Television Standards Committee, (U.S.) NTSC) semaphore request reaches perceptual sensitivity-94dBm requirement.And for the detection of the TV signal of current China, for Digital Television DTMB(Digital Television Terrestrial Multimedia Broadcasting, terrestrial DTV multimedia broadcasting) detection of signal, generally need perceptual sensitivity in-100dBm left and right, and simulated television PAL-D(Phase Alternating Line-D, directed mutual line-D) detection of signal, generally needs perceptual sensitivity in-70dBm left and right.

Recognizing radio is the radio adaptation environment in the perception external world first, and frequency spectrum perception needs the frequency of the current cognitive system work of periodic perception, thereby monitors the operating state of this frequency authoring system.But as mentioned above, frequency spectrum perception needs faint authoring system signal to be detected, and this requires frequency spectrum perception under low SNR environment, to obtain higher detection performance.But the perception under this low SNR environment, the impact that frequency spectrum perception is easy to be disturbed.If cognitive system is still in work when carrying out frequency spectrum perception, frequency spectrum perception is disturbed being subject to serious native system so, thereby reduces to a great extent the accuracy of frequency spectrum perception, and finally affects the performance of cognitive system.So the perception for cognitive system working frequency points at present need to keep cognitive system to mourn in silence.

In addition, the General Requirements frequency spectrum perception of existing cognitive radio system has stand-alone antenna and RF(Radio Frequency, radio frequency) unit, and in order to detect more reliably authoring system signal, the antenna of General Requirements frequency spectrum perception is omnidirectional antenna.As mentioned above, frequency spectrum perception also needs to meet certain perceptual sensitivity requirement.But the authoring system signal under above-mentioned sensitivity power, frequency spectrum perception probably can't detect, thereby thinks that frequency range is idle and in this frequency range work.But for some cognitive radio communication systems, the authoring system signal that frequency spectrum perception does not detect may cause the interference to cognitive radio communication systems.Such as: when TD-LTE system is used the TV free time for the detection of DTMB signal, if the DTMB signal power receiving is-105dBm, due to can only reach-100dBm of frequency spectrum perception sensitivity, frequency spectrum perception can not detect this signal, thereby in this frequency range work, the DTMB signal interference of still-105dBm power can cause the large capacitance loss of TD-LTE systematic comparison.

Consider the characteristic of general filter, filter device can not be accomplished desirable bandwidth.For transmitter, the adjacent frequency that filter non-ideal characteristic brings is revealed may cross over N neighboring trace.For cognitive radio system, some frequency range may frequency spectrum perception result be shown as the free time, but the interference due to adjacent frequency leakage, CR system can not be worked normally in this free time frequency range, as shown in Figure 1, for adjacent frequency in prior art is revealed and the schematic diagram of the interference that neighboring trace selection brings.

In fact, for the phase mutual interference between different radio electrical communication system, radio system need to meet the radio regulation(s) of this area.Existing wireless rule is to be different business fixed partition frequency ranges, such as requiring the frequency distribution of broadcasting service in intermediate frequency (MF), high frequency (HF), very high frequency(VHF) (VHF), or low superfrequency (UHF), and the frequency distribution of mobile service is in high superfrequency (UHF), hyperfrequency (SHF).Generally, different wireless systems again can the fixing frequency range of fixed allocation, and such as 470MHz ~ 798MHz frequency range is engaged in broadcasting service for TV system, and 2010MHz ~ 2025MHz frequency allocation is engaged in mobile service to TD-SCDMA system.The main purpose of fixing spectrum allocation may is can phase mutual interference when multiple radio traffic/system is worked simultaneously.On the whole, existing wireless system is to suppress to disturb between a plurality of radio systems by static spectrum allocation may and relevant wireless device deployment request.

Another one angle, in order to improve the quality of radio link under interference environment or fading environment, existing radio communication system, generally all has link circuit self-adapting function.Link circuit self-adapting just refers to that system is according to the current channel information obtaining, and the behavior of adjustment System transformation parameter adaptively, in order to overcome or to adapt to the impact that current channel variation is brought.Generally, link adaptation techniques mainly comprises following several technology:

(1) adaptive modulation and coding technology, according to modulation system and the code rate of the variation adjustment System transmission of wireless channel, when channel condition is reasonable, improve the grade of modulation and the speed of coding, when channel condition is poor, reduce the grade of modulation and the speed of coding.

(2) power control techniques, according to the variation adjustment System transmitting power of radio channel, in the situation that channel condition is good, reduces transmitting power, the in the situation that of bad channel conditions, improves transmitting power.

(3) hybrid automatic repeat request technology, by adjusting the redundant information of transfer of data, thereby obtains and retransmits/merge gain at receiving terminal, realize to the small dynamic range of channel, accurately, self adaptation fast.

(4) channel selectivity dispatching technique, according to the result of wireless channel measurement, the reasonable running time-frequency resource of selective channel condition carries out the transmission of data.

In realizing process of the present invention, inventor finds at least to exist in prior art following problem:

Existing frequency spectrum perception is passed through to detect authoring system system, thereby finds and use idle frequency spectrum resource to evade the interference between authoring system and cognitive radio system.This mode but only having when the authoring system signal strength signal intensity receiving is greater than perceptual sensitivity, the ability of frequency spectrum perception could correctly detect authoring system signal, although can be protected authoring system.When the authoring system signal power receiving requires lower than perceptual sensitivity, frequency spectrum perception can not detect authoring system signal, but this signal authoring system signal power may be still more intense, thereby may cause cognitive radio system to be interfered.

On the other hand, although some frequency spectrums, in the free time, because the adjacent frequency of the authoring system transmitter of adjacent band is revealed, cause this free time frequency range reality to be interfered.And existing frequency spectrum perception may can not detect this frequency range and is disturbed, and differentiate for idle frequency range.If cognitive radio is worked in this frequency range, may cause communication quality to be affected.

Cognitive radio system is that a kind of dynamic frequency spectrum is used system, and this is different from existing static spectrum allocation may mode.Because dynamic frequency spectrum is used, destroyed the interference environment of multiple wireless system under static spectrum allocation may, existing static spectrum allocation may rule is not suitable for cognitive radio system.

And existing link adaptation techniques can only resist the interference occurring on working band, and under interference environment, be the means such as grade or raising transmitting power of being modulated, encoded by reduction, this means obviously can be brought the loss of throughput of system.In the time of serious, communication link quality may can not meet customer requirement at all.

Summary of the invention

The embodiment of the present invention provides frequency point selecting method and the equipment in a kind of cognitive radio system, solves in existing technical scheme and can not carry out flexibly the problem of frequency selection and adjustment according to the practical communication quality of frequency.

For achieving the above object, the embodiment of the present invention provides the frequency point selecting method in a kind of cognitive radio system on the one hand, at least comprises the following steps:

Radio communication is carried out in base station in current working frequency points;

Described base station obtains the quality indication of current each communication link, and wherein, described quality indication is specially the quantized value of the mass parameter of current each communication link;

When triggering frequency adjustment processing, described base station is according to current idle frequency spectrum resource information, and the indication of corresponding quality, selects new working frequency points, and proceed radio communication in described new working frequency points.

On the other hand, the embodiment of the present invention also provides a kind of base station, comprising:

Communication module, for carrying out radio communication in current working frequency points;

Communication quality statistical module, for obtaining the quality indication of presently used each communication link of described communication module, wherein, described quality indication is specially the quantized value of the mass parameter of current each communication link;

Spectrum management module, while triggering frequency adjustment processing for the quality indication of obtaining when described communication quality statistical module, according to current idle frequency spectrum resource information, and the indication of corresponding quality, select new working frequency points, and proceed radio communication in described new working frequency points.

On the other hand, the embodiment of the present invention also provides the frequency point selecting method in a kind of cognitive radio system, comprises the following steps:

Terminal equipment carries out radio communication with base station in current working frequency points;

Described terminal equipment obtains the mass parameter of current down link, and quantizes to generate the quality indication of described down link;

Described terminal equipment is given described base station by the quality index uploading of described down link;

Wherein, the value of described quality indication is larger, and the communication quality of its corresponding communication link is better.

On the other hand, the embodiment of the present invention also provides a kind of terminal equipment, comprising:

Communication module, for carrying out radio communication with base station in current working frequency points;

Communication quality statistical module, for obtaining the mass parameter of current down link, and quantize to generate the quality indication of described down link, and notify described communication module by the quality index uploading of described down link to described base station;

Compared with prior art, the technical scheme that the embodiment of the present invention proposes has the following advantages:

By the technical scheme of the application embodiment of the present invention, base station is when carrying out radio communication, obtain the quality indication of current each communication link, and when triggering frequency adjustment processing, according to current idle frequency spectrum resource information, and corresponding quality indication, select new working frequency points, and proceed radio communication in new working frequency points, thereby, utilize the frequency spectrum of cognitive radio system dynamically to use ability, according to the communication quality of current working frequency self, carry out flexibly frequency spectrum selection, especially when the communication quality of current working frequency range can not meet the communication quality demand of cognitive radio, readjust on other available frequencies and carry out work, until find the frequency that meets self communication quality requirement, guaranteed that working frequency points can meet the communication quality requirement of system all the time, improved the communication quality of network, strengthened the reliability of system communication.

Accompanying drawing explanation

Fig. 1 is that in prior art, adjacent frequency is revealed and the schematic diagram of the interference that neighboring trace selection brings;

Fig. 2 is the schematic flow sheet of the frequency point selecting method in a kind of cognitive radio system of proposing of the embodiment of the present invention;

Fig. 3 is the schematic flow sheet of the frequency point selecting method in the cognitive radio system of a kind of application scheme one of proposing of the embodiment of the present invention;

Fig. 4 is the schematic flow sheet of the frequency point selecting method in the cognitive radio system of a kind of application scheme two of proposing of the embodiment of the present invention;

Fig. 5 is the structural representation of a kind of base station of proposing of the embodiment of the present invention;

Fig. 6 is the structural representation of a kind of terminal equipment of proposing of the embodiment of the present invention.

Embodiment

As stated in the Background Art, along with the fast development of mobile communication business, telecom operators will face frequency spectrum resource problem in short supply.Cognitive radio is considered to solve the effective means of the nervous problem of current frequency spectrum resource.But, thereby detecting having or not of authoring system signal by frequency spectrum perception, cognitive radio system protects authoring system, and frequency spectrum perception need to meet the requirement of detection sensitivity, and frequency spectrum perception can only detect the signal of authoring system under certain signal strength signal intensity.When the authoring system signal strength signal intensity receiving is during lower than the desired level of detection sensitivity, frequency spectrum perception cannot detect authoring system, but this time, authoring system signal may still can disturb cognitive radio.

In addition, because the adjacent frequency that filter non-ideal characteristic brings is revealed, the idle frequency range making may be disturbed by adjacent frequency.So frequency spectrum perception can not guarantee the glitch-free work of cognitive native system.

Above problem causes cannot effectively avoiding interference suffered in system by existing technical scheme, has affected the communication quality of system.

In order to overcome such defect, the embodiment of the present invention has proposed the frequency point selecting method in a kind of cognitive radio system, and the quantification in the method cycle is also added up the radio link quality of cognitive system.According to the quality indication of the communication link after quantizing, when finding that communication quality indication continues to be less than after certain thresholding, also be link communication Quality Down to a certain extent, trigger the adjustment that cognitive system is carried out frequency, thereby evade cognitive system in the long-time interference that is subject to of working frequency points.The method can effectively improve that cognitive system used that idle frequency spectrum resource communicates time communication quality, meanwhile, the method is used the measurement result of existing cognitive radio communication systems, to existing system, revises very little.The method is not only applicable to TDD system, is applicable to FDD system yet.

As shown in Figure 2, the schematic flow sheet of the frequency point selecting method in a kind of cognitive radio system proposing for the embodiment of the present invention, the method specifically comprises the following steps:

Radio communication is carried out in step S201, base station in current working frequency points.

Step S202, described base station obtain the quality indication of current each communication link.

Wherein, described quality indication is specially the quantized value of the mass parameter of current each communication link.

Concrete, above-mentioned mass parameter, at least comprises the one or more of following information:

Measure SNR;

Measurements interference level;

Link feedback NACK quantity in Preset Time section;

Desynchronizing state;

BLER level in Preset Time section;

The cell channel quality that terminal equipment feeds back is less than the number of times of default thresholding.

In concrete processing scene, can select one or more as mass parameter in above-mentioned each index, certainly, concrete mass parameter is not limited in above-mentioned listed parameter type, can select according to the actual needs.

Above information is all measurement indexes of prior art, adopts such metrical information as the foundation of subsequent treatment, can effectively reduce in order to realize the technical scheme that the embodiment of the present invention proposes and the improvement cost of the existing system carrying out.

In concrete application scenarios, consider the difference of uplink and downlink communication, the processing procedure in this step specifically comprises following two aspects:

(1) radio communication is carried out with each terminal equipment respectively in described base station in current working frequency points, obtain the mass parameter of the described corresponding up link of each terminal equipment, and the mass parameter of up link described in each is quantized, generate the quality indication of up link described in each.

(2) radio communication is carried out with each terminal equipment respectively in described base station in current working frequency points, the quality indication of the corresponding down link separately that described in receiving, each terminal equipment reports, wherein, described in each, the quality of down link indication is specially terminal equipment described in each and according to the mass parameter of corresponding down link, quantizes resulting respectively.

Further, no matter be which kind of above-mentioned situation, for the convenience of subsequent treatment, following rule is set in the embodiment of the present invention:

The value of described quality indication is larger, and the communication quality of its corresponding communication link is better.

Certainly; in actual applications; also can oppositely arrange; the value that quality indication is set is less; the communication quality of its corresponding communication link is better, and corresponding, the rule of subsequent treatment also will be adjusted accordingly; this is a kind of mode that characterizes communication channel quality state, and the variation of specific rules content does not affect protection scope of the present invention.

Further, the processing procedure of above-mentioned quantification specifically comprises:

The residing channel quality of identification mass parameter is interval, then, according to the interval corresponding numerical value of the channel quality recognizing, determines the numerical value after described mass parameter quantizes.

Wherein, described channel quality interval is specifically divided by default one or more mass parameter threshold values.

In actual applications, the mode in the above-mentioned residing channel quality of identification mass parameter interval, specifically comprises:

Determine the mean value of the quality indication of obtaining in continuing Preset Time section.

The magnitude relationship of more described mean value and described default one or more mass parameter threshold values.

Determine that the residing channel quality of described mean value is interval.

Below, the concrete measurement SNR of usining in cellular network, as the example of aforesaid mass parameter, describes the quantification treatment process of this step.

(1) the quality quantification method of up link.

The mass parameter (take and measure SNR as example) of the up link of each terminal equipment is added up in base station, and this mass parameter is quantized, and concrete quantization method is:

If the average SNR that n bar up link continues to measure in x ms is lower than the 0th thresholding, being designated as of this link-quality " Sn=0 ".

If the average SNR that n bar up link continues to measure in x ms is greater than the 0th thresholding and is less than the 1st thresholding, being designated as of this link-quality " Sn=1 ".

If the average SNR that n bar up link continues to measure in x ms is greater than the 1st thresholding and is less than the 2nd thresholding, being designated as of this link-quality " Sn=2 ".

Wherein, thresholding 0 < thresholding 1 < thresholding 2, this threshold value can be according to operator's demand configuration.

With roughly the same inferior, measurements interference level, desynchronizing state, the BLER level in certain period etc. also can be mapped as according to said method the indication of link-quality; In addition, above-mentioned processing procedure meets aforementioned rule, and communication link quality is better, and the value of the quality indication of this link is higher.

(2) the link-quality quantization method of down link.

The mass parameter (take and measure SNR as example) of the down link of terminal equipment statistics self, and this mass parameter is quantized, concrete quantization method is:

If the average SNR that the down link of terminal equipment continues to measure in x ms is lower than the 0th thresholding, being designated as of this link-quality " Sn=0 ".

If the average SNR that the down link of terminal equipment continues to measure in x ms is greater than the 0th thresholding and is less than the 1st thresholding, being designated as of this link-quality " Sn=1 ".

If the average SNR that the down link of terminal equipment continues to measure in x ms is greater than the 1st thresholding and is less than the 2nd thresholding, being designated as of this link-quality " Sn=2 ".

Wherein, thresholding 0 < thresholding 1 < thresholding 2, the demand configuration of this threshold value Ke You operator, and be broadcast to the terminal equipment in community by system message.

With roughly the same inferior, measurements interference level, desynchronizing state, the BLER level in certain period, terminal feedback cell channel quality are less than quantity of thresholding etc. also can be mapped as according to said method the indication of link-quality, in addition, above-mentioned processing procedure meets aforementioned rule, be that communication link quality is better, the value of the quality indication of this link is higher.

According to said process, terminal equipment completes after quantification treatment, and the quality indication Sn of down link is separately reported to base station.

Indicate according to described quality step S203, described base station, judges the current frequency adjustment processing that whether triggers.

When judgment result is that while being, execution step S204;

When the determination result is NO, return to step S202.

Step S204, described base station are according to current idle frequency spectrum resource information, and the indication of corresponding quality, select new working frequency points, and proceed radio communication in described new working frequency points.

It should be noted that, in concrete processing scene, according to the difference of concrete processing rule, the above-mentioned embodiment of the present invention can be divided into two schemes and realize corresponding technique effect, below, corresponding two schemes describes each step in the embodiment of the present invention respectively.

Scheme one, the processing scheme of measuring based on overall frequency spectrum resource, corresponding handling process schematic diagram as shown in Figure 3.

Step S301, when initialization is carried out in described base station, described base station is divided into a plurality of sub-bands by the current spendable frequency spectrum resource of described cognitive radio system.

Wherein, corresponding division rule specifically comprises:

Between each sub-band of dividing, do not occur simultaneously.

The bandwidth of each sub-band of dividing is identical or different.

Step S302, described base station are respectively sub-band described in each and set up quality indicator variable.

Concrete, the spectrum division that base station can be used by CR system is K sub-frequency bands, and be that every sub-frequency bands creates a quality indicator variable Q who characterizes sub-band spectra quality, wherein, Q1, Q2 ... QK represents respectively the quality indicator variable from the 1st sub-frequency bands to K sub-frequency bands.

Frequency spectrum perception is carried out to sub-band described in each respectively in step S303, described base station, determines the sub-band of current free time.

Step S304, described base station are in the sub-band of described current free time, and selector closes the corresponding frequency of one or more sub-bands of the communicating requirement of current system, as current working frequency points.

Base station is according to the spectrum requirement of communication system, and the free sub-band resource of selector hop communication system spectrum demand is as the working frequency points of communication system.

Further, if communication system needs a plurality of sub-bands, according to its demand, select continuous/discrete a plurality of free sub-bands as the working frequency points of communication system.

Step S305, be step S201, radio communication is carried out in base station in current working frequency points.

Step S306, be step S202, base station obtains the quality indication of current each communication link.

The mass parameter of interior received up link of a period of time is periodically added up in base station, and these mass parameters are carried out to quantitative statistics, generates corresponding quality indication.

And for the quality indication of down link, be to obtain the information that directly reports of the terminal equipment from receiving.

Average quality indication is determined in step S307, base station.

The quality indication of each up link that described base station generates according to self, determines the average quality indication of up link.

Wherein, the description in corresponding aforesaid step S202, base station is averaging the indication of the link-quality of N bar link, obtains the quality indication S of total up link:

S=(1/N)×∑ _n ^NS _n。

Meanwhile, the average quality indication of down link, according to the quality indication of each received down link, is determined in base station.

Wherein, the description in corresponding aforesaid step S202, the quality indication of the down link that base station reports N terminal equipment is averaged, and obtains total downlink quality indication S:

S=(1/N)×∑ _n ^NS _n。

Indication determines whether to trigger frequency adjustment processing according to average quality for step S308, base station.

When described base station determines that the average quality of described up link is indicated the frequency adjustment trigger conditions that reaches default, the frequency adjustment of described base station triggers up link is processed, execution step S310.

When described base station determines that the average quality of described down link is indicated the frequency adjustment trigger conditions that reaches default, the frequency adjustment of described base station triggers down link is processed, execution step S311.

When described base station determines that corresponding average quality is indicated the frequency adjustment trigger conditions that does not reach default, return to step S305, continue to carry out radio communication in current working frequency points.

Wherein, described frequency adjustment trigger conditions, is specially:

Described average quality indication is lower than adjusting threshold value; Or,

Described average quality indication continues to have reached default number of times threshold value lower than the number of times of adjusting threshold value.

Step S309, base station are upgraded quality indicator variable.

In actual application scenarios, the processing of this step comprises following two kinds of situations:

Situation one, described base station, according to the average quality indication of the average quality indication of described up link and down link, are upgraded the quality indicator variable of the current corresponding sub-band of working frequency points.

In such cases, the sign of link communication quality is carried out in base station by the quality indicator variable of accumulation type, corresponding average quality indication is accumulated on the numerical value of current quality indicator variable, thereby, the communication quality of the corresponding communication link of sign of continuation, react more accurately the communications status of this communication link, can avoid paroxysmal variations for the impact of quality testing result.

Concrete, the Frequency spectrum quality of the current sub-band taking of link can be recorded in base station according to the average quality indication S reporting at every turn, and its method of operation can be:

If it is m that communication system working frequency points takies sub-band, m+1, m+2, upgrading result is Q _m=Q _m+ S, Q _m+1=Q _m+1+ S, Q _m+2=Q _m+2+ S.

Situation two, described base station, according to the quality indication of current each communication link, are upgraded the quality indicator variable of the current corresponding sub-band of working frequency points.

In such cases, base station is directly upgraded quality indicator variable according to current quality indication, can clearly react current link communication quality, more be conducive to the link of selecting current communication quality best, avoid historical data for the impact of current measurement result.

Concrete, base station can directly be upgraded the indicator variable Q of sub-band spectra quality according to the quality indication S reporting at every turn, that is:

If it is m that communication system working frequency points takies sub-band, m+1, m+2, the quality reporting indication is respectively S _m, S _m+1, S _m+2, upgrading result is Q _m=S _m, Q _m+1=S _m+1, Q _m+2=S _m+2.

In actual application scenarios, the renewal that concrete employ situation is carried out quality indicator variable can be set according to the actual needs, and such variation does not affect protection scope of the present invention.

It should be noted that, step S308 and step S309 are all the steps of carrying out after step S307 completes, and there is no inevitable precedence relationship between the two, and the variation of execution sequence, can't affect protection scope of the present invention.

Step S310, described base station are in the current free time, and meet in the sub-band of communicating requirement of current system, select quality indicator variable value maximum sub-band or quality indicator variable with the corresponding frequency of a plurality of sub-bands maximum as new working frequency points, and in described new working frequency points, proceed the radio communication of up direction.

Step S311, described base station are in the current free time, and meet in the sub-band of communicating requirement of current system, select quality indicator variable value maximum sub-band or quality indicator variable with the corresponding frequency of a plurality of sub-bands maximum as new working frequency points, and described new working frequency points is notified to corresponding terminal equipment, so that described base station and corresponding terminal equipment are proceeded the radio communication of down direction in described new working frequency points.

Scheme two, the processing scheme based on attempting link, above-mentioned scheme one is according to link-quality, to adjust working frequency points after CR system is started working on idle frequency, be different from the method in scheme one, before CR system is started working on idle frequency, can attempt setting up wireless link on this free time frequency, and differentiate the whether applicable CR system works of current frequency according to the method in scheme one, corresponding handling process schematic diagram is as shown in Figure 4.

Step S401, described base station, in the current spendable frequency spectrum resource of described cognitive radio system, obtain idle band resource.

Carrier wave is set up in step S402, described base station on the idle band resource of communicating requirement that meets current system.

Step S403, described base station scheduling terminal equipment are to described carrier wave, and the described corresponding frequency of idle band resource that meets the communicating requirement of current system of take is current working frequency points, carries out radio communication.

Step S404, be step S202, base station obtains the quality indication of current each communication link.

Average quality indication is determined in step S405, base station.

The average quality indication of the frequency spectrum resource that current carrier wave is shared, according to the quality indication of each communication link, is determined in described base station.

Indication determines whether to trigger frequency adjustment processing according to average quality for step S406, base station.

When described base station determines that the quality of described carrier wave is indicated the frequency adjustment trigger conditions that reaches default, execution step S407.

When described base station determines that the quality of described carrier wave is indicated the frequency adjustment trigger conditions that does not reach default, execution step S408.

Dispatch back the terminal equipment on current described carrier wave on corresponding former work carrier wave step S407, described base station, and using respectively the corresponding frequency of band resource at corresponding former work carrier wave place as new working frequency points.

Step S408, described base station continue scheduling other-end equipment to described carrier wave according to the demand of offered load, and with the corresponding frequency of band resource at described carrier wave place, as the new working frequency points of each other-end equipment being scheduled.

No matter it should be noted that, be above-mentioned scheme one or scheme two, and for TDD system, base station can determine whether communication system adjusts the working frequency points of TDD communication system according to the quality indication S of up or down link.

And for FDD system, base station determines whether to adjust the up working frequency points of FDD communication system according to the quality indication S of up link; According to the quality indication S of down link, determine whether to adjust the descending working frequency points of FDD communication system.

Further, if comprise ，Ze base station, a plurality of sector under a base station, independently carry out respectively the link-quality monitoring of each sector and independently according to link-quality, adjust the working frequency points of each sector.

On the other hand, in terminal equipment side, for cellular network, need to carry out the processing procedure of the quality indication of the secondary described down link of abovementioned steps S202, according to the mass parameter of current down link, quantize to generate corresponding quality indication, and reporting base station, concrete processing procedure is referring to above stated specification, at this repeated description no longer.

Below, in conjunction with concrete application scenarios, the technical scheme that the embodiment of the present invention is proposed describes.

The embodiment of the present invention has proposed a kind of method that link quality condition Dynamic trigger frequency according to wireless communication system is adjusted.

Because cognitive radio system has the ability that frequency spectrum is dynamically used, it can select frequency spectrum flexibly according to current working frequency points self communication quality, more specifically, when the communication quality of current working frequency points can not meet the communication quality demand of cognitive radio, cognitive radio is adjusted on other available frequency and is worked, until find the frequency that meets self communication quality requirement.

Below, by specific embodiment, describe.

Embodiment mono-

In this embodiment, suppose that operative scenario is that the TD-LTE with cognitive radio function is used the idle frequency range of TV, wherein, TD-LTE bandwidth is 20MHz, and the bandwidth of TV is 8MHz.

Further, suppose that frequency spectrum perception carries out the detection of idle frequency spectrum with 8MHz frequency bandwidth.

TD-LTE base station has frequency spectrum sensing module and Dynamic Spectrum Management module, increases Frequency spectrum quality statistical module.

(1), during initialization, spectrum management module is divided into the whole frequency range being utilized according to the band characteristics of TV the sub-band of 8MHz bandwidth, and to each channel number.

Such as, 8 sub-channels altogether from 694MHz to 758MHz.

(2) spectrum management module is that every sub-channels creates Frequency spectrum quality indication Q1 ~ Q8.

Initialization Q1=Q2=Q3=Q4=Q5=Q6=Q7=Q8=0.

(3) frequency spectrum sensing module of TD-LTE base station side is pressed the idle frequency range of 8MHz bandwidth detection TV one by one, and the idle frequency range detecting is reported to spectrum management module.

(4) spectrum management module, according to TD-LTE bandwidth demand (20MHz), is selected continuous 3 idle sub-channels, as the working frequency points (such as having selected to be numbered 5,6,7 TV channel) of the 1st sector of TD-LTE.

(5) community is set up in sector, the 1st of TD-LTE base station in working frequency points, receives terminal.

(6) SNR of average upward signal in the 1st every of sector up link 5ms of communication quality statistical module periodic statistics of TD-LTE base station, and by this mean value and thresholding comparison.

Wherein, for n bar up link:

If this mean value is greater than the 0th SNR decision threshold and is less than a SNR decision threshold, make link-quality indication Sn=0;

If this mean value is greater than a SNR decision threshold and is less than the 2nd SNR decision threshold, make link-quality indication Sn=1;

If this mean value is greater than the 2nd SNR decision threshold and is less than Three S's NR decision threshold, make link-quality indication Sn=2.

(7) the communication quality statistical module of base station is averaging the indication of the link-quality of the 1st sector N bar link, obtains total uplink quality indication S:

S=(1/N)×∑ _n ^NS _n。

(8) the communication quality statistical module of TD-LTE base station reports Dynamic Spectrum Management module by the S value of the 1st sector.

(9) Dynamic Spectrum Management module is Q5=Q5+S, Q6=Q6+S, Q7=Q7+S.

If S=2, repeats (6) to (9).

If S < 2, carry out (10)

(10) Dynamic Spectrum Management module selects continuous 3 Q values and maximum idle TV channel as the working frequency points of the 1st sector, new TD-LTE base station in idle channel.

(11) spectrum management module triggers the 1st of TD-LTE base station sector working frequency points and adjusts, and adjusts in new working frequency points.

Embodiment bis-:

The CR system of supposing multicarrier has only activated a carrier wave at present, and this system wishes to set up the 2nd carrier wave on idle frequency.

(1) CR system obtains idle frequency band resource by frequency spectrum perception.

(2) CR system is selected suitable idle frequency band.

(3) on the idle frequency band that CR system is selected in step S602, set up the 2nd carrier wave, and dispatch a small amount of terminal works in the 2nd carrier wave.

(4) CR system quantifies add up the quality of the 2nd carrier wave uplink, obtains link-quality indication S.

If the quality S=2 of the 2nd carrier wave uplink, carries out (5);

If quality S < 2 of the 2nd carrier wave uplink, carry out (6).

(5) according to other terminal works of offered load demand dispatch in the 2nd carrier wave.

(6) terminal scheduling on the 2nd carrier wave is arrived to original carrier wave, and reselect suitable idle frequency band, repeat above-mentioned (3) to (4).

In order to realize the technical scheme of the embodiment of the present invention, the embodiment of the present invention also provides a kind of base station, and its structural representation as shown in Figure 5, at least comprises:

Communication module 51, for carrying out radio communication in current working frequency points;

Communication quality statistical module 52, for obtaining the quality indication of described communication module 51 presently used each communication links, wherein, described quality indication is specially the quantized value of the mass parameter of current each communication link;

Spectrum management module 53, while triggering frequency adjustment processing for the quality indication of obtaining when described communication quality statistical module 52, according to current idle frequency spectrum resource information, and corresponding quality indication, select new working frequency points, and proceed radio communication in described new working frequency points.

Wherein, described communication quality statistical module 52, specifically for:

In current working frequency points, carry out radio communication with each terminal equipment respectively, obtain the mass parameter of the described corresponding up link of each terminal equipment, and the mass parameter of up link described in each is quantized, generate the quality indication of up link described in each;

In current working frequency points, carry out radio communication with each terminal equipment respectively, the quality indication of the corresponding down link separately that described in receiving, each terminal equipment reports, wherein, described in each, the quality of down link indication is specially terminal equipment described in each and according to the mass parameter of corresponding down link, quantizes resulting respectively;

Further, spectrum management module 53, also for:

When initialization is carried out in described base station, the current spendable frequency spectrum resource of described cognitive radio system is divided into a plurality of sub-bands, and is respectively sub-band described in each and sets up quality indicator variable;

Respectively sub-band described in each is carried out to frequency spectrum perception, determine the sub-band of current free time;

In the sub-band of described current free time, selector closes the corresponding frequency of one or more sub-bands of the communicating requirement of current system, and notifies described communication module 51, using selected frequency as current working frequency points.

Further, described communication quality statistical module 52, also for:

According to the quality indication of each up link, determine the average quality indication of up link, according to the quality indication of each down link, determine the average quality indication of down link;

When the average quality of described up link is indicated the frequency adjustment trigger conditions that reaches default, the frequency adjustment of notifying described spectrum management module 53 to trigger up links is processed;

When the average quality of described down link is indicated the frequency adjustment trigger conditions that reaches default, the frequency adjustment of notifying described spectrum management module 53 to trigger down links is processed.

In concrete processing scene, described spectrum management module 53, also for:

According to the average quality indication of the average quality indication of described up link and down link, the quality indicator variable of the current corresponding sub-band of working frequency points is upgraded; Or,

According to the quality indication of current each communication link, the quality indicator variable of the current corresponding sub-band of working frequency points is upgraded.

Accordingly, described spectrum management module 53, also for:

When triggering the frequency adjustment processing of up link, in the current free time, and meet in the sub-band of communicating requirement of current system, select quality indicator variable value maximum sub-band or quality indicator variable with the corresponding frequency of a plurality of sub-bands maximum as new working frequency points, and in described new working frequency points, proceed the radio communication of up direction;

When triggering the frequency adjustment processing of down link, in the current free time, and meet in the sub-band of communicating requirement of current system, select quality indicator variable value maximum sub-band or quality indicator variable with the corresponding frequency of a plurality of sub-bands maximum as new working frequency points, and described new working frequency points is notified to corresponding terminal equipment, so that described base station and corresponding terminal equipment are proceeded the radio communication of down direction in described new working frequency points.

On the other hand, described spectrum management module 53, also for:

In the current spendable frequency spectrum resource of described cognitive radio system, obtain idle band resource;

On the idle band resource of communicating requirement that meets current system, set up carrier wave;

Notify described communication module 51 dispatch terminal equipment to described carrier wave, the described corresponding frequency of idle band resource that meets the communicating requirement of current system of take is current working frequency points, carries out radio communication.

Further, described spectrum management module 53, also for:

When the quality of described carrier wave is indicated the frequency adjustment trigger conditions that reaches default, notify described communication module 51 that the terminal equipment on current described carrier wave is dispatched back on corresponding former work carrier wave, and using respectively the corresponding frequency of band resource at corresponding former work carrier wave place as new working frequency points;

When the quality of described carrier wave is indicated the frequency adjustment trigger conditions that does not reach default, notify described communication module 51 to continue scheduling other-end equipment to described carrier wave according to the demand of offered load, and with the corresponding frequency of band resource at described carrier wave place, as the new working frequency points of each other-end equipment being scheduled.

On the other hand, the embodiment of the present invention also provides a kind of terminal equipment, and its structural representation as shown in Figure 6, comprising:

Communication module 61, for carrying out radio communication with base station in current working frequency points;

Communication quality statistical module 62, for obtaining the mass parameter of current down link, and quantize to generate the quality indication of described down link, and notify described communication module 61 by the quality index uploading of described down link to described base station;

Further, described communication quality statistical module 62, is specially:

The residing channel quality of identification mass parameter is interval;

According to the interval corresponding numerical value of the channel quality recognizing, determine the numerical value after described mass parameter quantizes;

Through the above description of the embodiments, those skilled in the art can be well understood to the embodiment of the present invention and can realize by hardware, and the mode that also can add necessary general hardware platform by software realizes.Understanding based on such, the technical scheme of the embodiment of the present invention can embody with the form of software product, it (can be CD-ROM that this software product can be stored in a non-volatile memory medium, USB flash disk, portable hard drive etc.) in, comprise some instructions with so that computer equipment (can be personal computer, server, or network equipment etc.) carry out the embodiment of the present invention each implement the method described in scene.

It will be appreciated by those skilled in the art that accompanying drawing is a schematic diagram of preferably implementing scene, the module in accompanying drawing or flow process might not be that the enforcement embodiment of the present invention is necessary.

It will be appreciated by those skilled in the art that the module in the device of implementing in scene can be distributed in the device of implementing scene according to implementing scene description, also can carry out respective change and be arranged in the one or more devices that are different from this enforcement scene.The module of above-mentioned enforcement scene can be merged into a module, also can further split into a plurality of submodules.

The invention described above embodiment sequence number, just to describing, does not represent the quality of implementing scene.

Disclosed is above only the several concrete enforcement scene of the embodiment of the present invention, and still, the embodiment of the present invention is not limited thereto, and the changes that any person skilled in the art can think of all should fall into the traffic limits scope of the embodiment of the present invention.

Claims

1. a frequency point selecting method in cognitive radio system, is characterized in that, comprises the following steps:

radio communication is carried out in base station in current working frequency points;

2. the method of claim 1, is characterized in that, described base station obtains the quality indication of current each communication link, specifically comprises:

radio communication is carried out with each terminal equipment respectively in described base station in current working frequency points, obtain the mass parameter of the described corresponding up link of each terminal equipment, and the mass parameter of up link described in each is quantized, generate the quality indication of up link described in each;

radio communication is carried out with each terminal equipment respectively in described base station in current working frequency points, the quality indication of the corresponding down link separately that described in receiving, each terminal equipment reports, wherein, described in each, the quality of down link indication is specially terminal equipment described in each and according to the mass parameter of corresponding down link, quantizes resulting respectively;

wherein, the value of described quality indication is larger, and the communication quality of its corresponding communication link is better.

3. method as claimed in claim 2, is characterized in that, the processing procedure of described quantification, is specially:

the residing channel quality of identification mass parameter is interval;

according to the interval corresponding numerical value of the channel quality recognizing, determine the numerical value after described mass parameter quantizes;

wherein, described channel quality interval is specifically divided by default one or more mass parameter threshold values.

4. method as claimed in claim 3, is characterized in that, the residing channel quality of described identification mass parameter is interval, specifically comprises:

determine the mean value of the quality indication of obtaining in continuing Preset Time section;

the magnitude relationship of more described mean value and described default one or more mass parameter threshold values;

determine that the residing channel quality of described mean value is interval.

5. the method of claim 1, is characterized in that, described base station also comprised carry out radio communication in current working frequency points before:

when initialization is carried out in described base station, described base station is divided into a plurality of sub-bands by the current spendable frequency spectrum resource of described cognitive radio system;

described base station is respectively sub-band described in each and sets up quality indicator variable;

frequency spectrum perception is carried out to sub-band described in each respectively in described base station, determines the sub-band of current free time;

described base station is in the sub-band of described current free time, and selector closes the corresponding frequency of one or more sub-bands of the communicating requirement of current system, as current working frequency points.

6. method as claimed in claim 5, is characterized in that, described base station is divided into the current spendable frequency spectrum resource of described cognitive radio system the rule of a plurality of sub-bands, specifically comprises:

between each sub-band of dividing, do not occur simultaneously;

the bandwidth of each sub-band of dividing is identical or different.

7. method as claimed in claim 5, is characterized in that, described base station also comprises after obtaining the quality indication of current each communication link:

the average quality indication of up link, according to the quality indication of each up link, is determined in described base station, according to the quality indication of each down link, determines the average quality indication of down link;

when described base station determines that the average quality of described up link is indicated the frequency adjustment trigger conditions that reaches default, the frequency adjustment of described base station triggers up link is processed;

when described base station determines that the average quality of described down link is indicated the frequency adjustment trigger conditions that reaches default, the frequency adjustment of described base station triggers down link is processed.

8. method as claimed in claim 7, is characterized in that, described frequency adjustment trigger conditions, is specially:

described average quality indication is lower than adjusting threshold value; Or,

described average quality indication continues to have reached default number of times threshold value lower than the number of times of adjusting threshold value.

9. method as claimed in claim 7, is characterized in that, described base station also comprises after obtaining the quality indication of current each communication link:

described base station, according to the average quality indication of the average quality indication of described up link and down link, is upgraded the quality indicator variable of the current corresponding sub-band of working frequency points; Or,

described base station, according to the quality indication of current each communication link, is upgraded the quality indicator variable of the current corresponding sub-band of working frequency points.

10. method as claimed in claim 9, is characterized in that, when triggering frequency adjustment processing, described base station is according to current idle frequency spectrum resource information, and the indication of corresponding quality, selects new working frequency points, and proceed radio communication in described new working frequency points, specifically comprise:

when the frequency adjustment of described base station triggers up link is processed, described base station is in the current free time, and meet in the sub-band of communicating requirement of current system, select quality indicator variable value maximum sub-band or quality indicator variable with the corresponding frequency of a plurality of sub-bands maximum as new working frequency points, and in described new working frequency points, proceed the radio communication of up direction;

when the frequency adjustment of described base station triggers down link is processed, described base station is in the current free time, and meet in the sub-band of communicating requirement of current system, select quality indicator variable value maximum sub-band or quality indicator variable with the corresponding frequency of a plurality of sub-bands maximum as new working frequency points, and described new working frequency points is notified to corresponding terminal equipment, so that described base station and corresponding terminal equipment are proceeded the radio communication of down direction in described new working frequency points.

11. the method of claim 1, is characterized in that, described base station also comprised carry out radio communication in current working frequency points before:

described base station, in the current spendable frequency spectrum resource of described cognitive radio system, obtains idle band resource;

carrier wave is set up in described base station on the idle band resource of communicating requirement that meets current system;

described base station scheduling terminal equipment is to described carrier wave, and the described corresponding frequency of idle band resource that meets the communicating requirement of current system of take is current working frequency points, carries out radio communication.

12. method as claimed in claim 11, is characterized in that, described base station also comprises after obtaining the quality indication of current each communication link:

when described base station determines that the quality of described carrier wave is indicated the frequency adjustment trigger conditions that reaches default, dispatch back the terminal equipment on current described carrier wave on corresponding former work carrier wave described base station, and using respectively the corresponding frequency of band resource at corresponding former work carrier wave place as new working frequency points;

when described base station determines that the quality of described carrier wave is indicated the frequency adjustment trigger conditions that does not reach default, scheduling other-end equipment is continued to described carrier wave according to the demand of offered load in described base station, and with the corresponding frequency of band resource at described carrier wave place, as the new working frequency points of each other-end equipment being scheduled.

13. method as described in any one in claim 1 to 12, is characterized in that, described mass parameter at least comprises the one or more of following information:

measure signal to noise ratio snr;

measurements interference level;

link feedback in Preset Time section negates indication NACK quantity;

desynchronizing state;

block error rate BLER level in Preset Time section;

the cell channel quality that terminal equipment feeds back is less than the number of times of default thresholding.

14. , it is characterized in that, comprising:

communication module, for carrying out radio communication in current working frequency points;

15. base station as claimed in claim 14, is characterized in that, described communication quality statistical module, specifically for:

16. base station as claimed in claim 14, is characterized in that, spectrum management module, also for:

respectively sub-band described in each is carried out to frequency spectrum perception, determine the sub-band of current free time;

in the sub-band of described current free time, selector closes the corresponding frequency of one or more sub-bands of the communicating requirement of current system, and notifies described communication module, using selected frequency as current working frequency points.

17. base station as claimed in claim 16, is characterized in that, described communication quality statistical module, also for:

when the average quality of described up link is indicated the frequency adjustment trigger conditions that reaches default, notify the frequency adjustment that described spectrum management module triggers up link to process;

when the average quality of described down link is indicated the frequency adjustment trigger conditions that reaches default, notify the frequency adjustment that described spectrum management module triggers down link to process.

18. base station as claimed in claim 17, is characterized in that, described spectrum management module, also for:

according to the quality indication of current each communication link, the quality indicator variable of the current corresponding sub-band of working frequency points is upgraded.

19. base station as claimed in claim 18, is characterized in that, described spectrum management module, also for:

20. base station as claimed in claim 14, is characterized in that, described spectrum management module, also for:

in the current spendable frequency spectrum resource of described cognitive radio system, obtain idle band resource;

on the idle band resource of communicating requirement that meets current system, set up carrier wave;

notify described communication module dispatch terminal equipment to described carrier wave, the described corresponding frequency of idle band resource that meets the communicating requirement of current system of take is current working frequency points, carries out radio communication.

21. base station as claimed in claim 20, is characterized in that, described spectrum management module, also for:

when the quality of described carrier wave is indicated the frequency adjustment trigger conditions that reaches default, notify described communication module that the terminal equipment on current described carrier wave is dispatched back on corresponding former work carrier wave, and using respectively the corresponding frequency of band resource at corresponding former work carrier wave place as new working frequency points;

when the quality of described carrier wave is indicated the frequency adjustment trigger conditions that does not reach default, notify described communication module to continue scheduling other-end equipment to described carrier wave according to the demand of offered load, and with the corresponding frequency of band resource at described carrier wave place, as the new working frequency points of each other-end equipment being scheduled.

22. a frequency point selecting method in cognitive radio system, is characterized in that, comprises the following steps:

terminal equipment carries out radio communication with base station in current working frequency points;

described terminal equipment obtains the mass parameter of current down link, and quantizes to generate the quality indication of described down link;

described terminal equipment is given described base station by the quality index uploading of described down link;

23. method as claimed in claim 22, is characterized in that, the processing procedure of described quantification, is specially:

the residing channel quality of identification mass parameter is interval;

24. method as claimed in claim 23, is characterized in that, the residing channel quality of described identification mass parameter is interval, specifically comprises:

25. , it is characterized in that, comprising:

communication module, for carrying out radio communication with base station in current working frequency points;

26. terminal equipment as claimed in claim 25, is characterized in that, described communication quality statistical module, is specially:

the residing channel quality of identification mass parameter is interval;