CN104104457B - Based on frequency spectrum detection distribution method and the system of ground digital television broadcast frequency range - Google Patents

Abstract

The invention discloses a spectrum detection and allocation method and system based on terrestrial digital television broadcasting frequency bands. The baseband processing module is loaded with an energy detection algorithm and a cyclic prefix algorithm. The energy detection algorithm can detect frequency bands by setting an energy threshold value for use in Detect frequency bands not occupied by cognitive users. The cyclic prefix algorithm is specially used to detect DVB-T signals. In the frequency band occupied by cognitive users, the cyclic prefix algorithm can detect whether there is an authorized user reoccupying the frequency band. If an authorized user is detected, the cognitive user will stop immediately. Occupy this frequency band to avoid interference to licensed users. The invention can detect all frequency bands of DVB-T frequency bands, switch frequency bands adaptively, find out idle frequency bands accurately and in real time, and allocate them to each cognitive user for use. On this basis, the present invention can also detect the appearance of authorized users and make cognitive users exit in time and switch to other idle frequency bands.

Description

Spectrum detection and allocation method and system based on terrestrial digital television broadcast frequency band

technical field

The invention relates to the field of communication technology, in particular to a method and system for frequency spectrum detection and allocation based on terrestrial digital television broadcasting frequency bands.

Background technique

At present, wireless communication devices are increasing rapidly, but spectrum resources available for wireless communication are becoming increasingly scarce, and spectrum resources are becoming more and more precious. However, there are a large number of "spectrum holes" in the licensed frequency band. These "spectrum holes" are not used by authorized users most of the time. How to use these "spectrum holes" has become a research hotspot. Cognitive radio spectrum detection technology emerged as the times require, which allows unlicensed users (cognitive users) to use licensed user frequency bands for communication when licensed users do not use "spectrum holes". How to detect idle frequency bands that are not used by licensed users has become an important research point. At the same time, after detecting idle frequency bands, how to allocate these idle frequency bands to cognitive users who need to communicate is also very important. DVB-T refers to the standard of digital terrestrial television broadcasting system, and its frequency band ranges from 50 to 878Mhz. DVB-T frequency bands are often only occupied in a certain period of time, and some frequency bands are not fully utilized for a long time. Therefore, under the condition of not interfering with authorized users of the DVB-T frequency band, making full use of the idle frequency band can greatly improve the utilization rate of spectrum.

At present, the spectrum detection method of cognitive radio often uses algorithms such as energy detection, which can only detect the presence or absence of signals, but cannot identify authorized signals. For DVB-T signals, the cyclic prefix detection algorithm can be used for detection, but this method cannot identify whether there are other signals in the frequency band. Combining the above two algorithms can realize accurate detection of frequency bands. However, a lot of time will be wasted if two algorithms are used for detection in each frequency band at the same time. In addition, in the utilization of vacant frequency bands, cognitive users often initiate spectrum detection, and occupy vacant frequency bands when they are detected, so that re-detection is required each time the frequency band is authorized to be reoccupied. Such frequent spectrum detection will waste the transmission time of cognitive users. And when the licensed user returns to the occupied frequency band, the cognitive user will cause interference to the licensed user.

Contents of the invention

The technical problem to be solved by the present invention is to provide a spectrum detection and allocation method and system based on terrestrial digital television broadcasting frequency bands, which can detect the full frequency bands of DVB-T frequency bands, switch frequency bands adaptively, find out idle frequency bands in real time and Assigned to each Cognitive User. On this basis, the present invention can also detect the appearance of authorized users and make cognitive users exit in time and switch to other idle frequency bands.

In order to solve the above problems, the present invention is achieved through the following technical solutions:

The frequency spectrum detection allocation method based on the terrestrial digital television broadcasting frequency band comprises the following steps:

(1) The cognitive central processor sends a communication request to the base station communicator through the cognitive communicator, the base station communicator transmits the request information to the base station central processor, and the base station central processor records the number of cognitive users;

(2) The radio frequency antenna receives the DVB-T frequency band signal, and the radio frequency front-end divides the whole frequency band into several sub-bands according to the preset sub-band bandwidth, and the base station central processor moves each sub-band to zero by changing the output frequency of the radio frequency front-end local oscillator frequency, and divide it into two channels of I and Q and send it to the baseband processing module;

(3) The base station central processor is provided with an idle frequency band spectrum pool and an allocated frequency band spectrum pool; the base station central processor judges in turn whether each sub-frequency band in the DVB-T frequency band exists in the allocated frequency band spectrum pool;

When the sub-frequency band does not exist in the allocated frequency band spectrum pool, it means that the sub-frequency band is not occupied by cognitive users; the base station central processor sends an energy detection command to the baseband processing module, and the baseband processing module uses the energy detection method to judge the sub-frequency band Whether it is idle; when the sub-frequency band is judged as an idle frequency band, the baseband processing module sends an idle command to the base station central processor, and the base station central processor puts the sub-frequency band into the idle frequency band spectrum pool and controls the radio frequency The front-end local oscillator immediately switches to the next sub-frequency band; when the sub-frequency band is judged as a non-idle frequency band, the baseband processing module sends a command to the base station central processor to occupy the sub-frequency band, and the base station central processor directly controls the RF front-end local oscillator switch to the next sub-band;

When the sub-frequency band exists in the allocated frequency band spectrum pool, it means that the sub-frequency band has been occupied by cognitive users; Whether there is a DVB-T signal in the frequency band; when no DVB-T signal is detected in the sub-frequency band, that is, there is no authorized user, the baseband processing module sends the command that the sub-frequency band is occupied by cognitive users to the central processor of the base station, and the central processor of the base station Keep the sub-frequency band in the allocated frequency band spectrum pool, and then control the RF front-end local oscillator to switch to the next sub-frequency band; when the sub-frequency band detects a DVB-T signal, that is, there are authorized users, the baseband processing module will process it to the base station center The transmitter sends the command that the sub-frequency band is occupied by authorized users, the central processor of the base station suspends the frequency band switching of the RF front-end local oscillator, and immediately sends the command that the sub-frequency band is occupied to the cognitive communicator through the base station communication machine, and then moves the sub-frequency band out The frequency band spectrum pool has been allocated, and then continue to control the RF front-end local oscillator to switch to the next sub-frequency band; the cognitive communicator then notifies the cognitive center processor to immediately stop occupying the sub-frequency band and initiate a communication request to the base station again;

(4) After the base station central processor detects the complete DVB-T frequency band, the idle frequency band spectrum pool in the base station central processor records all idle frequency band information, and all allocated frequency band information is recorded in the allocated frequency band spectrum pool; meanwhile, the base station central processor The processor broadcasts the free frequency band information in the free frequency band spectrum pool through the base station communicator according to the number of cognitive users, and the cognitive communicator receives the free frequency band information broadcast by the base station communicator, and transmits the free frequency band information to the cognitive center processor , the cognitive central processor controls the local oscillator of the cognitive user to adjust the communication frequency to an idle frequency band, and the cognitive users use the idle frequency band for communication; at the same time, the base station central processor puts the broadcasted idle frequency band information into the allocated In the frequency band spectrum pool;

(5) The above is a detection cycle. After the detection of a cycle is completed and the free frequency band is allocated, the central processor of the base station clears the spectrum pool of the free frequency band and starts the detection of the next cycle.

In the above step (2), the preset sub-band bandwidth is set to 8MHz.

In the above step (3), the central processor of the base station only puts the intermediate value of the sub-frequency bands judged as idle into the idle frequency band spectrum pool.

The spectrum detection and allocation system based on the terrestrial digital TV broadcast frequency band designed based on the above method is mainly composed of a base station central processor, a radio frequency front end, a baseband processing module, a base station communicator, a cognitive central processor, a cognitive communicator and a cognitive user Composition; the data output end of the RF front end is connected to the baseband processing module; the base station central processor is respectively connected to the RF front end local oscillator of the RF front end, the baseband processing module and the base station communicator; the cognitive central processor is respectively connected to the cognitive user of the cognitive user The local oscillator and the cognitive communicator; the base station communicator and the cognitive communicator are connected through an antenna.

In the above scheme, the radio frequency front end is mainly composed of radio frequency antenna, front low pass filter, low noise amplifier, attenuator, second stage amplifier, mixer, radio frequency front end local oscillator, rear low pass filter and automatic gain controller Sequential connection composition; the output end of the RF antenna is connected to the input end of the front low-pass filter; the output end of the front low-pass filter is connected to the input end of the low-noise amplifier; the output end of the low-noise amplifier is connected to the second-stage amplifier through the attenuator The input terminals are connected; the output terminal of the second-stage amplifier is connected to one input terminal of the mixer, and the central processor of the base station is connected to the other input terminal of the mixer through the RF front-end local oscillator; the output terminals of the mixer are divided into I and Q Two output terminals, I and Q two output terminals are respectively connected to one input terminal of the baseband processing module after passing through a post low-pass filter and an automatic gain controller.

In the above-mentioned scheme, described I, Q two-way output ends are respectively connected with 2-stage automatic gain controller, connect I, Q two-way output ends respectively connect the input end of the first-stage automatic gain amplifier, the first-stage automatic gain amplifier The output end is connected with the input end of the second-stage automatic gain amplifier through a post-low-pass filter.

In the above solution, both the cognitive communicator and the base station communicator are 2.4G communicators.

Compared with the prior art, the present invention has the following advantages:

1. The RF front-end of the spectrum detection and distribution system adopts a zero-IF structure. It only needs to control the local oscillator to output different frequencies through the central processor to directly mix different frequency points to the baseband. Compared with the secondary frequency conversion structure, many components are reduced. , which saves costs and improves system integration; at the same time, it also solves the problem of image interference in the secondary frequency conversion.

2. Two spectrum pools are used, which can automatically read out which frequency bands are free and which frequency bands are occupied by cognitive users and authorized users, and the spectrum pools can be automatically updated. Dynamic spectrum allocation is performed according to the idle frequency band in the spectrum pool, and multiple cognitive users can communicate with each other; after the authorized user returns, the base station can quickly detect the authorized user and notify the cognitive user to exit the frequency band in time and switch to other idle frequency bands .

3. Make full use of the characteristics of the energy detection algorithm and the cyclic prefix detection algorithm, and choose different detection methods in different situations, which can not only improve the detection accuracy, but also effectively save the detection time.

4. Cognitive users do not need to perform spectrum detection before they need to communicate. They only need to initiate a request to receive the idle frequency band information sent by the base station, which prolongs the communication time of cognitive users and improves the utilization of idle spectrum.

Description of drawings

Fig. 1 is a flowchart of a spectrum detection and allocation method based on terrestrial digital television broadcast frequency bands.

Figure 2 is an overall block diagram of a spectrum detection and distribution system based on terrestrial digital television broadcasting frequency bands.

Figure 3 is a connection block diagram of the RF front end.

detailed description

A method for frequency spectrum detection and allocation based on terrestrial digital television broadcast frequency band, as shown in Figure 1, comprises the steps:

(1) The cognitive central processor sends a communication request to the base station communicator through the cognitive communicator, the base station communicator transmits the request information to the base station central processor, the base station central processor records the number of cognitive users, and spectrum detection begins.

(2) The radio frequency antenna receives the DVB-T frequency band signal, and the radio frequency front-end divides the whole frequency band into several sub-bands according to the preset sub-band bandwidth, and the base station central processor moves each sub-band to zero by changing the output frequency of the radio frequency front-end local oscillator frequency, and divide it into I and Q two channels and send it to the baseband processing module. In a preferred embodiment of the present invention, the preset sub-band bandwidth is set to 8MHz.

For example, the central processor of the base station controls the local oscillator to output a frequency of 54MHz, and then moves the frequency band to the baseband after mixing with the 50-58MHz sub-band by the quadrature demodulator. At this time, all information of the 50-58MHz frequency band is available in the 0-4MHz frequency band , through the post-low-pass filter with a bandwidth of 4M, the information in the 50-58M frequency band is AD sampled and then sent to the FPGA for digital processing.

(3) The base station central processor is provided with a free frequency band spectrum pool (No. 1 spectrum pool) and an allocated frequency band spectrum pool (No. 2 spectrum pool); the base station central processor determines in turn whether each sub-frequency band in the DVB-T frequency band exists In the spectrum pool of allocated frequency bands. If there is data in the spectrum pool of the allocated frequency band, such as 54 MHz, it indicates that the sub-frequency band of 50-58 MHz has been occupied by cognitive users.

When the sub-band does not exist in the allocated frequency band spectrum pool, it means that the sub-band is not occupied by cognitive users; at this time, the base station central processor sends an energy detection command (such as sending 0) to the baseband processing module, and the baseband processing module Adopt energy detection method to judge whether this sub-frequency band is idle; The sub-frequency band is put into the idle frequency band spectrum pool, and the RF front-end local oscillator is controlled to switch to the next sub-frequency band (such as 62MHz) immediately; when the sub-frequency band is judged as a non-idle frequency band, the baseband processing module sends For the command occupied by the sub-frequency band (such as sending 1), the central processor of the base station directly controls the RF front-end local oscillator to switch to the next sub-frequency band (such as 62MHz). In a preferred embodiment of the present invention, the central processor of the base station does not put the entire frequency band of the sub-frequency band judged as idle into the idle frequency band spectrum pool, but only puts the intermediate value of the sub-frequency band judged as idle into the idle frequency band spectrum in the pool. For example, if it is judged that the sub-band of 50-58 MHz is free, then the intermediate value of 54 MHz is put into the idle frequency band spectrum pool instead of the frequency band value of 50-58 MHz being put into the idle frequency band spectrum pool.

When the sub-frequency band exists in the allocated frequency band spectrum pool, it means that the sub-frequency band has been occupied by cognitive users; the base station central processor sends a cyclic prefix detection command (such as sending 1) to the baseband processing module, and the baseband processing module uses the cyclic prefix The detection method judges whether there is a DVB-T signal in the sub-frequency band; when no DVB-T signal is detected in the sub-frequency band, that is, there is no authorized user, the baseband processing module sends the command that the sub-frequency band is occupied by cognitive users to the central processor of the base station (such as sending 2), the central processor of the base station reserves the sub-frequency band in the allocated frequency band spectrum pool, and then controls the RF front-end local oscillator to switch to the next sub-frequency band (such as 62MHz); when the sub-frequency band detects the DVB-T signal That is, when there is an authorized user, the baseband processing module sends an order to the base station central processor that the sub-frequency band is occupied by the authorized user (such as sending 3), and the base station central processor suspends the frequency band switching of the RF front-end local oscillator, and sends it immediately through the base station communicator The command that the sub-frequency band is occupied is given to the cognitive communicator, and then the sub-frequency band is moved out of the allocated frequency band spectrum pool, and then the RF front-end local oscillator is controlled to switch to the next sub-frequency band; the cognitive communicator then notifies the cognitive central processor Immediately stop occupying the sub-frequency band to avoid interference with authorized users, and the cognitive users send communication requests to the base station through the cognitive communicator again. Authorized users are DVB-T signals, and the sub-bands of the DVB-T frequency band are not used all the time, and there are some idle frequency bands; so the cognitive radio can detect these idle frequency bands and make use of them.

(4) After the central processor of the base station detects the entire DVB-T frequency band (that is, when the central processor of the base station controls the output of the local oscillator to 878MHz, the local oscillator jump is suspended), the free frequency band spectrum pool in the central processor of the base station records all the free frequency bands information, all allocated frequency band information is recorded in the allocated frequency band spectrum pool; at the same time, the central processor of the base station broadcasts the free frequency band information in the free frequency band spectrum pool through the base station communicator in sequence according to the number of cognitive users, and the cognitive communicator receives the base station communication The idle frequency band information broadcast by the machine, and transmit the idle frequency band information to the cognitive central processor, the cognitive central processor controls the local oscillator of the cognitive user to adjust the communication frequency to the idle frequency band, and the cognitive users use the idle frequency band for communication ; At the same time, the base station central processor puts the broadcasted free frequency band information into the allocated frequency band spectrum pool.

(5) The above is a detection cycle. After the detection of a cycle is completed and the free frequency band is allocated, the central processor of the base station clears the spectrum pool of the free frequency band and starts the detection of the next cycle.

The invention proposes a cognitive spectrum detection method with high detection precision and fast speed, which can simultaneously realize spectrum allocation and reduce frequency spectrum detection times of cognitive users. In addition, when authorized users occupy the frequency band again, the spectrum allocation method can enable cognitive users to exit in time and switch to other vacant frequency bands.

The spectrum detection and allocation system based on the terrestrial digital TV broadcast frequency band designed based on the above method, as shown in Figure 2, mainly consists of a base station central processor, a radio frequency front end, a baseband processing module, a base station communicator, a cognitive central Composition of communicators and cognitive users. The data output end of the RF front-end is connected to the baseband processing module; the base station central processor is respectively connected to the RF front-end local oscillator of the RF front-end, the baseband processing module and the base station communicator; the cognitive central processor is respectively connected to the cognitive user local oscillator of the cognitive user and the cognitive communicator; the base station communicator is connected to the cognitive communicator through an antenna.

The RF front-end uses a zero-IF structure to move the RF signal to zero frequency. As shown in Figure 3, the RF front-end mainly consists of an RF antenna, a front low-pass filter, a low-noise amplifier, an attenuator, a second-stage amplifier, a mixer, and a radio frequency The front-end local oscillator, the rear low-pass filter and the automatic gain controller are sequentially connected. The output end of the radio frequency antenna is connected to the input end of the front low-pass filter; the output end of the front low-pass filter is connected to the input end of the low-noise amplifier; the output end of the low-noise amplifier is connected to the input end of the second stage amplifier through the attenuator; The output end of the second-stage amplifier is connected to one input end of the mixer, and the central processor of the base station is connected to the other input end of the mixer through the RF front-end local oscillator; the output end of the mixer is divided into two output ends of I and Q : Wherein the output end of the I road is connected to the input end of the first-stage automatic gain amplifier of the I road, the output end of the first-stage automatic gain amplifier of the I road passes through the low-pass filter after the I road and the input end of the second-stage automatic gain amplifier of the I road Connected; the output terminal of the Q channel is connected to the input terminal of the first-stage automatic gain amplifier of the Q channel, and the output terminal of the first-stage automatic gain amplifier of the Q channel passes through the post-Q low-pass filter and the input terminal of the second-stage automatic gain amplifier of the Q channel connected. The RF antenna receives the DVB-T frequency band signal, and linearly amplifies it through the low-noise amplifier. The low-noise amplifier adopts MAX2130, and the working range is 50-878Mhz, which can cover the whole frequency band of DVB-T; The frequency of the local oscillator is mixed. The RF front-end local oscillator is composed of a phase-locked loop and a single-chip microcomputer. The phase-locked loop uses ADF4351, and its output frequency range is 35MHz) 4400MHz. Write the corresponding register value into the phase-locked loop through the single-chip microcomputer. Change the output frequency of the phase-locked loop; the central processor of the base station controls the local oscillator to output the corresponding local oscillator frequency to mix with the RF signal, and mix the intermediate frequency points of each sub-band to zero intermediate frequency. The mixer adopts the ADL5387 chip, and the working frequency The range is 30MHz) to 2GHz, which can be directly down-converted and modulated. The I/Q two-way baseband signal generated after the local oscillator frequency is mixed with the radio frequency signal, each of the I/Q two-way baseband signals passes through a 4M low-pass filter and automatically After the gain control, the signal is sent to the baseband processing module.

The baseband processing module is composed of a dual-channel analog-to-digital converter and a digital chip FPGA. The output of the radio frequency receiving module is connected to the input of the analog-to-digital converter, and the output of the analog-to-digital converter is connected to the input of the FPGA. The analog-to-digital converter adopts the AD9248 chip, which is a 14-bit dual-channel AD conversion chip; the I/Q two-way signal is converted into a digital baseband signal after AD conversion; the digital chip FPGA uses the CycloneIIEP2C8Q240C8N chip of ALTERA Company as the core, and the digital baseband signal Once it goes into the FPGA it is digitally processed. The digital processor inside the FPGA performs spectrum detection on each input sub-frequency band to determine whether the sub-frequency band is free and whether there is an authorized user signal. That is, the digital chip is loaded with an energy detection algorithm and a cyclic prefix algorithm. The energy detection algorithm can detect the frequency band by setting the energy threshold, which is used to detect the frequency band not occupied by cognitive users. The cyclic prefix algorithm is an algorithm generated according to the characteristics of DVB-T signals. It is specially used to detect DVB-T signals. In the frequency band occupied by cognitive users, the cyclic prefix algorithm can detect whether there is an authorized user reoccupying the frequency band. If the authorized user is detected, the cognitive user will immediately stop occupying the frequency band to avoid interference to the authorized user.

Both the cognitive communicator and the base station communicator are 2.4G communicators. The 2.4G communication machine of the base station broadcasts the free frequency band in the spectrum pool according to the number of cognitive users. The Cognitive 2.4G communicator receives the free frequency band information and transmits it to the Cognitive Central Processor.

The central processor of the base station is mainly responsible for ① controlling the change of the output frequency of the local oscillator; ② feeding back the baseband processing results, and selecting different processing methods according to the results; ③ constructing a spectrum pool; ④ controlling the 2.4G communication machine to broadcast idle frequency bands. The cognitive central processor is responsible for sending communication requests to the central processor of the base station, receiving idle frequency band information from the base station, and controlling the cognitive user to communicate by controlling the local oscillator of the cognitive user.

The spectrum pools in the central processor of the base station include a spectrum pool of idle frequency bands (ie, spectrum pool No. 1) and a spectrum pool of allocated frequency bands (ie, spectrum pool No. 2). Spectrum pool No. 1 puts all idle frequency bands into it by receiving information from the baseband processing module and making a judgment. Spectrum pool No. 2 places all allocated frequency bands that are occupied by cognitive users. Whenever free frequency bands are allocated, free frequency bands corresponding to the number of cognitive users are broadcast from No. 1 spectrum pool, and these free frequency bands are moved to No. 2 spectrum pool. No. 1 spectrum pool does not retain information about these frequency bands.

Claims (7)

1., based on the frequency spectrum detection distribution method of ground digital television broadcast frequency range, it is characterized in that comprising the steps:

(1) cognitive center processor by cognitive communications machine to base station communication machine send communication request, base station communication machine by request message transmission to base station center processor, base station center processor for recording cognitive user quantity;

(2) radio-frequency antenna receives DVB-T frequency band signals, radio-frequency front-end by whole frequency range according to preset the several frequency sub-band of frequency sub-band bandwidth fragmentation, each frequency sub-band is moved zero-frequency by the output frequency changing radio-frequency front-end local oscillator by base station center processor, and sends in baseband processing module after being divided into I, Q two-way;

(3) be provided with idle frequency range spectrum pool in base station center processor and distributed frequency range spectrum pool; Base station center processor judges whether each frequency sub-band in DVB-T frequency range is present in successively and has distributed in frequency range spectrum pool;

When frequency sub-band be not present in distributed in frequency range spectrum pool time, namely represent that this frequency sub-band is not taken by cognitive user; Now, base station center processor sends the order of energy measuring to baseband processing module, and baseband processing module adopts energy detection method to judge that whether this frequency sub-band is idle; When this frequency sub-band is judged as idle frequency range, then baseband processing module sends the order of this frequency sub-band free time to base station center processor, this frequency sub-band is put into idle frequency range spectrum pool by base station center processor, and controls radio-frequency front-end local oscillator and be switched to next son frequency range at once; When this frequency sub-band is judged as busy frequency range, then baseband processing module sends to base station center processor the order that this frequency sub-band takies, and base station center processor directly controls radio-frequency front-end local oscillator and is switched to next son frequency range;

When frequency sub-band be present in distribute in frequency range spectrum pool time, namely represent that this frequency sub-band is taken by cognitive user; Base station center processor sends the order of Cyclic Prefix detection to baseband processing module, and baseband processing module adopts ring prefix detection method to judge whether there is DVB-T signal in this frequency sub-band; When this frequency sub-band does not detect DVB-T signal namely without authorized user, then baseband processing module sends this frequency sub-band to base station center processor and is taken order by cognitive user, this frequency sub-band is retained in and distributes in frequency range spectrum pool by base station center processor, then controls radio-frequency front-end local oscillator and is switched to next frequency sub-band; When this frequency sub-band detects that namely DVB-T signal has an authorized user, then baseband processing module sends this frequency sub-band to base station center processor and is authorized to CU order, the frequency range that base station center processor suspends radio-frequency front-end local oscillator switches, and send the occupied order of this frequency sub-band to cognitive communications machine by base station communication machine at once, then this frequency sub-band is shifted out and distribute frequency range spectrum pool, control radio-frequency front-end local oscillator subsequently and be switched to next frequency sub-band; Cognitive communications machine notifies that cognitive center processor stops taking this frequency sub-band also again to base station initiating communication request at once thereupon;

(4) after base station center processor detects complete DVB-T frequency range, in base station center processor, idle frequency range spectrum pool have recorded available free band information, has distributed in frequency range spectrum pool have recorded and has allly distributed band information; Simultaneously, idle band information in idle frequency range spectrum pool is broadcasted away by base station communication machine according to cognitive user quantity by base station center processor, cognitive communications machine receives the idle band information of base station communication machine broadcast, and this idle band information is transferred to cognitive center processor, cognitive center processor controls cognitive user local oscillator adjustment communication frequency to idle frequency range, utilizes this idle frequency range to communicate between cognitive user; Meanwhile, the idle band information of broadcasting away is put into and is distributed frequency range spectrum pool by base station center processor;

(5) be a sense cycle more than, when one-period detect complete and by idle frequency allocation after, base station center processor empties idle frequency range spectrum pool, and starts the detection of next cycle.

2. according to claim 1 based on the frequency spectrum detection distribution method of ground digital television broadcast frequency range, it is characterized in that, in above-mentioned steps (2), the frequency sub-band bandwidth preset is set to 8MHz.

3., according to claim 1 based on the frequency spectrum detection distribution method of ground digital television broadcast frequency range, in above-mentioned steps (3), base station center processor only will be judged as that the median of idle frequency sub-band is put in idle frequency range spectrum pool.

4. frequency spectrum detection distribution method and the frequency spectrum detection distribution system based on ground digital television broadcast frequency range designed according to claim 1, is characterized in that: form primarily of base station center processor, radio-frequency front-end, baseband processing module, base station communication machine, cognitive center processor, cognitive communications machine and cognitive user; The data output end of radio-frequency front-end is connected with baseband processing module; Base station center processor connects the radio-frequency front-end local oscillator of radio-frequency front-end, baseband processing module and base station communication machine respectively; Cognitive center processor connects cognitive user local oscillator and the cognitive communications machine of cognitive user respectively; Cognitive user is connected with cognitive communications machine; Base station communication machine is connected by antenna with cognitive communications machine.

5. the frequency spectrum detection distribution system based on ground digital television broadcast frequency range according to claim 4, is characterized in that: described radio-frequency front-end to be linked in sequence composition primarily of radio-frequency antenna, front low pass filter, low noise amplifier, attenuator, second level amplifier, frequency mixer, radio-frequency front-end local oscillator, rear low pass filter and automatic gain controller; The output of radio-frequency antenna connects the input of front low pass filter; The output of front low pass filter connects the input of low noise amplifier; The output of low noise amplifier is connected through the input of attenuator with second level amplifier; The output of second level amplifier connects an input of frequency mixer, and base station center processor connects another input of frequency mixer through radio-frequency front-end local oscillator; The output of frequency mixer is divided into I, Q two-way output, I, Q two-way output respectively through after after low pass filter and automatic gain controller, be connected with a road input of baseband processing module.

6. the frequency spectrum detection distribution system based on ground digital television broadcast frequency range according to claim 5, it is characterized in that: described I, Q two-way output is respectively connected to 2 grades of automatic gain controllers, connect the input that I, Q two-way output respectively connects first order automatic gain amplifier, the output of first order automatic gain amplifier through after low pass filter be connected with the input of second level automatic gain amplifier.

7. the frequency spectrum detection distribution system based on ground digital television broadcast frequency range according to claim 4, is characterized in that: described cognitive communications machine and base station communication machine are 2.4G communication equipment.