WO2015035804A1

WO2015035804A1 - Broadband spectrum sensing method, fusion center, sensing node and system

Info

Publication number: WO2015035804A1
Application number: PCT/CN2014/079505
Authority: WO
Inventors: 李岩; 王军; 张力; 刘星; 闫如胜; 王斌
Original assignee: 中兴通讯股份有限公司
Priority date: 2013-09-11
Filing date: 2014-06-09
Publication date: 2015-03-19
Also published as: CN104426620A

Abstract

The present invention relates to the field of communications. Disclosed are a broadband spectrum sensing method, a fusion center (FC), a sensing node (SN) and a computer storage medium. The method comprises: the FC obtaining statistical idle probabilities of all current primary user (PU) physical channels; based on a sequence of the statistical idle probabilities from large to small, assigning SNs used for detecting channel spectrums to the PU physical channels in sequence; using the SNs assigned to the PU physical channels to detect the channel spectrums for the PU physical channels; and based on channel spectrum detection results, determining status of the PU physical channels.

Description

Broadband spectrum sensing method, data fusion center, sensing node and system

The present invention relates to communication technologies, and in particular, to a database-based high-efficiency broadband spectrum sensing method, a data fusion center, a sensing node, a system, and a computer storage medium. Background technique

Cognitive Radio (CR) technology is proposed to solve the problem of scarcity of resources currently encountered. Spectrum sensing algorithm is one of the key technologies of cognitive radio. In practice, the primary user (PU, Primary User) system is usually a broadband system. Some PU systems have hundreds of megabytes of bandwidth and dozens of channels, and some PU systems even have frequency channel resources across frequency bands. For example, China Mobile Multimedia Broadcasting (CMMB) system, U-band transmission frequency is 470MHz ~ 798MHz (36 channels;), S-band transmission frequency is 2635MHz ~ 2660MHz. Generally, the occupation of the physical channels of the PU system is independent of each other, that is, the adjacent physical channels of the PU system are not related to each other by the PU system. Therefore, the CRRC (Cognitive Radio Cell) should accurately detect the usage status of the attempted access channel of the cell before utilizing the physical channel resources of the PU system.

Due to the limited physical resources for spectrum sensing in the CRC, including the number of sensing nodes (SNs, Sensing Nodes) and the perceived data reporting channel resources, the traditional single-channel spectrum sensing strategy is difficult to detect the physicality of the PU system in a short time. channel. In addition, under the traditional single-channel spectrum sensing strategy, the CRC requires a large data interaction overhead, and the primary broadband spectrum sensing period is long, which will greatly affect the spectrum sensing accuracy and CRC transmission capacity of the CRC. Summary of the invention

Embodiments of the present invention provide a broadband spectrum sensing method, a data fusion center (FC, Fusion Center), an SN, a system, and a computer storage medium, which can better solve the traditional single channel spectrum sense. The problem that the idle PU physical channel probability is low and the data interaction overhead is large is detected in the knowledge strategy.

The technical solution of the embodiment of the present invention is implemented as follows:

The embodiment of the invention provides a broadband spectrum sensing method, including:

The FC obtains the statistical idle probability of all current PU physical channels.

And assigning, to the PU physical channel, a sensing node SN for channel frequency detection according to the statistical idle probability in descending order;

Using the SN allocated for the PU physical channel, performing channel spectrum detection on the PU physical channel;

The state of the PU physical channel is determined according to the channel frequency detection result.

Preferably, the statistical idle probability is a ratio of the PU physical channel idle time to the total time obtained by the frequency detection.

Preferably, the FC obtains a statistical idle probability of all the PU physical channels, and the method includes: the FC accesses the spectrum sensing database, and obtains a statistical idle probability of all current PU physical channels.

Preferably, the SN for sequentially allocating the channel frequency for the PU physical channel according to the order of the statistical idle probability is as follows:

For the current PU physical channel selected from the PU physical channel, the FC randomly selects one SN from the SN to be allocated and allocates the current SN to the current PU physical channel, and according to the number and signal of the received antenna of the selected SN. Determining whether the selected SN satisfies a preset false alarm probability and a detection probability of the current PU physical channel by using the sample number and the received signal to noise ratio;

If the judgment result is satisfied, one SN is selected from the remaining SNs to be allocated to the next PU physical channel selected from the PU physical channel, up to the PU physical channel, in descending order of statistical idle probability. All the SNs are allocated, and the SN allocated by each of the PU physical channels satisfies a preset false alarm probability and a detection probability of the corresponding PU physical channel;

If the judgment result is not satisfied, the FC randomly selects the SN according to the selected number of SNs, until the selected SN satisfies the preset false alarm probability of the current PU physical channel. And detection probability.

Preferably, the utilizing the SN to perform channel frequency detection on the PU physical channel includes:

Instructing the SN to perform a received signal on the corresponding PU physical channel to obtain multiple signals.

Instructing the SN to calculate local normalized energy data corresponding to the PU physical channel by using the plurality of signal sample samples, and using the local normalized energy data to obtain local spectrum sensing data;

The obtained local spectrum sensing data is used as a channel frequency detection result of the corresponding PU physical channel.

Preferably, the determining, according to the channel frequency detection result, the state of the PU physical channel, including:

The FC performs data fusion on the PU physical channel according to the local spectrum sensing data obtained by the SN, and obtains a global spectrum sensing statistic of the PU physical channel; respectively, global spectrum sensing of the PU physical channel The statistic is compared with the decision threshold. If the statistic is smaller than the decision threshold, it is determined that the PU physical channel is in an idle state.

Preferably, the data fusion is performed on the PU physical channel to obtain a global spectrum sensing statistic of the PU physical channel, including:

Calculating a weighting factor for fusing the local spectrum sensing data of the SN according to the number of receiving antennas, the number of signal samples, and the received signal to noise ratio of the SN;

Calculating a global spectrum sensing statistic of the corresponding PU physical channel according to the local spectrum sensing data of the SN and the weighting factor.

Preferably, the method further includes:

When it is determined that the state of a certain PU physical channel is an idle state, information of the PU physical channel in an idle state is transmitted to all SNs within the coverage of the FC. An embodiment of the present invention further provides an FC, where the FC includes:

The database query unit is configured to obtain a statistical idle probability of all current PU physical channels;

The SN allocation unit is configured to allocate, according to the statistical idle probability, the sensing node SN for channel frequency detection in sequence, in order of the statistical idle probability;

The channel frequency detection unit is configured to perform channel spectrum detection on the PU physical channel by using an SN allocated for the PU physical channel;

The channel state determining unit is configured to determine the state of each PU physical channel according to the channel frequency detection result.

Preferably, the database querying unit is further configured to determine, by the frequency detection, a ratio of the PU physical channel idle time to the total time as a statistical idle probability of the PU physical channel.

Preferably, the database query unit is further configured to access the spectrum sensing database to obtain a statistical idle probability of all current PU physical channels.

Preferably, the SN allocation unit includes:

a selection module, configured to randomly select one SN from the SN to be allocated to the current PU physical channel for the current PU physical channel selected from the PU physical channel; the determining module is configured to be based on the selected SN The number of receiving antennas, the number of signal samples and the received signal to noise ratio, determining whether the selected SN satisfies the preset false alarm probability and detection probability of the current PU physical channel;

If the judgment result is satisfied, the selection unit is triggered to select one SN from the remaining SNs to be allocated to the next PU physical channel selected from the PU physical channel, in descending order of statistical idle probability, until The PU physical channels are all allocated SN, and the SN allocated by each of the PU physical channels satisfies a preset false alarm probability and a detection probability of the corresponding PU physical channel; if the determination result is not satisfied, the selection unit is triggered according to the selection unit. The selected SN is randomly selected one by one to randomly select the SN until the selected SN satisfies the current PU physical channel. Preset false alarm probability and detection probability.

Preferably, the channel frequency detection unit comprises:

a first indication module, configured to instruct the SN to receive a signal on the corresponding PU physical channel, to obtain a plurality of signal samples;

a second indication module, configured to instruct the SN to calculate local normalized energy data of the corresponding PU physical channel by using the plurality of signal sample samples, and use the local normalized energy data to obtain local spectrum sensing data The obtained local spectrum sensing data is used as a channel frequency detection result of the corresponding PU physical channel.

Preferably, the channel state determining unit includes:

a local spectrum sensing data receiving module, configured to receive local spectrum sensing data from the SN;

a data fusion module configured to perform data fusion on the PU physical channel to obtain a global spectrum sensing statistic of the PU physical channel;

The determining module is configured to compare the global spectrum sensing statistic of the PU physical channel with the determining threshold, and if the threshold is smaller than the determining threshold, determine that the PU physical channel is in an idle state.

Preferably, the data fusion module includes:

a first calculation submodule configured to calculate a weighting factor for fusing the local spectrum sensing data of the SN according to the number of receiving antennas, the number of signal samples, and the received signal to noise ratio of the SN;

The second computing submodule is configured to calculate a global spectrum sensing statistic of the corresponding PU physical channel according to the local spectrum sensing data of the SN and the weighting factor.

Preferably, the channel state determining unit is further configured to: when determining that the state of a certain PU physical channel is an idle state, send information of the PU physical channel in an idle state to all SNs in the FC coverage. An embodiment of the present invention further provides an SN, where the SN includes:

The signal sampling unit is configured to perform receiving signals on the corresponding PU physical channel according to the allocation result of the data fusion center FC, to obtain a plurality of signal samples;

a normalized energy calculation unit configured to calculate a correspondence by using the plurality of signal sample samples

Local normalized energy data of the PU physical channel; using the local normalized energy data to obtain local spectrum sensing data; and using the obtained local spectrum sensing data as a channel frequency detection result of the corresponding PU physical channel.

The embodiment of the invention provides a broadband spectrum sensing system, including:

The FC is configured to obtain a statistical idle probability of all the current PU physical channels; and sequentially allocate, for the PU physical channel, the sensing node SN for the channel frequency detection according to the statistical idle probability; The SN allocated by the PU physical channel performs channel spectrum detection on the PU physical channel; and determines a state of the PU physical channel according to a channel spectrum detection result;

The SN is configured to perform, according to the allocation result of the FC, the received signal of the corresponding PU physical channel, to obtain a plurality of signal samples; and use the plurality of signal samples to calculate a local locality of the corresponding PU physical channel. Generating energy data; using the local normalized energy data to obtain local spectrum sensing data; and using the obtained local spectrum sensing data as a channel frequency detection result of the corresponding PU physical channel.

Preferably, the FC is further configured to access a spectrum sensing database to obtain a statistical idle probability of all current PU physical channels.

Preferably, for the current PU physical channel selected from the PU physical channel, the FC is further configured to randomly select one SN from the SN to be allocated and allocate the SN to the current PU physical channel, and according to the selected SN. Number of receiving antennas, number of signal samples, and received signal-to-noise ratio, Determining whether the selected SN satisfies the preset false alarm probability and the detection probability of the current PU physical channel; if the judgment result is satisfied, according to the statistical idle probability from the largest to the smallest, from the remaining

Selecting one SN from the SN to allocate to the next PU physical channel selected from the PU physical channel, until the PU physical channel is allocated SN, and each PU physical channel is allocated

The SN satisfies a preset false alarm probability and a detection probability of the corresponding PU physical channel;

If the result of the determination is not satisfied, the SN is randomly selected according to the number of selected SNs, until the selected SN satisfies the preset false alarm probability and detection probability of the current PU physical channel.

Preferably, the FC is further configured to instruct the SN to receive a signal for the corresponding PU physical channel to obtain a plurality of signal sample samples;

Preferably, the FC is further configured to perform data fusion on the PU physical channel according to the local spectrum sensing data obtained by the SN, to obtain a global spectrum sensing statistic of the PU physical channel;

The global spectrum sensing statistic of the PU physical channel is compared with a decision threshold, and if the threshold is smaller than the threshold, the PU physical channel is determined to be in an idle state.

Preferably, the FC is further configured to calculate, respectively, a weighting factor for fusing the local spectrum sensing data of the SN according to the number of receiving antennas of the SN, the number of signal samples, and the received signal to noise ratio;

Calculating a global spectrum sensing statistic of the corresponding PU physical channel according to the local spectrum sensing data of the SN and the weighting factor. The embodiment of the invention further provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and the computer executable instructions are used to execute the broadband spectrum sensing method described above.

Compared with related technologies, the beneficial effects of the embodiments of the present invention are:

The embodiment of the present invention can improve the probability of successfully detecting that the PU physical channel is in an idle state, and reduce the system overhead caused by all SNs participating in spectrum sensing;

2. By counting the statistical idle probability of the PU physical channel of the PU system, the FC selects the preferentially perceived PU physical channel, which can improve the probability of successfully detecting the PU physical channel in an idle state, thereby improving spectrum utilization and increasing the capacity of the CRC. Reduce the time to find the spectrum hole of the PU physical channel, and improve the efficiency of spectrum sensing;

3. According to the system performance requirements, the FC allocates the SN to the PU physical channel to perform spectrum sensing. The system can select the appropriate number of SNs to meet the system performance requirements, and reduce the system overhead caused by all SNs participating in spectrum sensing. The number of SNs participating in the cooperative spectrum sensing is reduced under the premise of ensuring the spectrum sensing performance, thereby reducing the overhead of data interaction between the SN and the FC caused by the broadband cooperative spectrum, and detecting the state of the PU physical channel by using the limited SN. . DRAWINGS

1 is a schematic block diagram of a broadband spectrum sensing method according to an embodiment of the present invention;

2 is a flowchart of a broadband spectrum sensing method according to an embodiment of the present invention;

FIG. 3 is a flowchart of acquiring local spectrum sensing data according to an embodiment of the present invention;

4 is a structural block diagram of a broadband spectrum sensing system according to an embodiment of the present invention;

FIG. 5 is a structural block diagram of an SN according to an embodiment of the present invention;

FIG. 6 is a structural block diagram of an FC according to an embodiment of the present invention. detailed description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, The preferred embodiments illustrated are for illustrative purposes only and are not intended to limit the invention. In the embodiment of the present invention, the FC obtains the statistical idle probability of all the PU physical channels from the spectrum sensing database, and arranges the channel sensing order according to the PU physical channel statistical idle probability, and counts the channel priority sensing with high idle probability. Then, the FC allocates an appropriate number of sensing nodes SN to the PU physical channel to be perceived according to the preset false alarm probability and the detection probability in the system, and instructs the SN to perform channel sensing (ie, performs channel spectrum detection;). The SN obtains the local spectrum sensing statistic by using the normalized energy detector, and performs data processing on the spectrum sensing statistic to obtain the final local spectrum sensing data, which is reported to the FC. Finally, the FC receives the local spectrum sensing data from the plurality of SNs, and performs data fusion and decision on the received local spectrum sensing data of the plurality of SNs, and notifies the currently idle PU physical channel to the cognitive radio users in the coverage area. .

FIG. 1 is a schematic block diagram of a broadband spectrum sensing method according to an embodiment of the present invention. As shown in FIG. 1 , the method includes the following steps:

Step 101: The FC acquires a statistical idle probability of all current PU physical channels.

The statistical idle probability of the PU physical channel is the ratio of the PU physical channel idle time to the total time obtained by long-term spectrum sensing update.

As an implementation of the step 101, the FC may obtain the statistical idle probability of the PU physical channel by periodically accessing the spectrum sensing database, and sequentially arrange the statistical idle probability of the PU physical channel in descending order to construct the sensing. The channel order list, so that the FC priority allocates enough SNs to the PU physical channel with high statistical idle probability.

Step 102: Allocate the SN of the channel frequency detection for the PU physical channel in descending order of the statistical idle probability.

As an implementation of step 102, for a current PU physical channel selected from the PU physical channel, the FC may randomly select one SN from the SN to be allocated and allocate the current SN to the current PU physical channel, and according to the allocated SN. The number of receiving antennas, the number of samples of the signal, and the received signal-to-noise ratio, and determining whether the allocated SN satisfies the preset false alarm probability of the current PU physical channel And the probability of detection; if the judgment result is satisfied, the FC randomly selects one SN from the remaining SNs to allocate the next PU physical channel according to the order of statistical idle probability; if the judgment result is not satisfied, the FC follows the The selected SN is randomly selected one by one to randomly select the SN until the selected SN satisfies the preset false alarm probability and detection probability of the current PU physical channel;

For example, first, the FC obtains the number of receiving antennas, the number of signal samples, and the received signal-to-noise ratio of the SN in the coverage area of the FC for use in allocating the SN for the PU physical channel. This step can be implemented by related technologies. Therefore, the FC does not repeat the description; then, according to the requirements of the system for detecting probability and false alarm probability, the FC selects enough SNs to perceive a certain PU physical channel until the selected SNs are allocated for sensing the PU physical channel. Or all PU physical channels have been assigned SN.

Step 103: Perform channel spectrum detection on the PU physical channel by using the SN allocated to the PU physical channel.

As an implementation of the step 103, the FC indicates that the SN allocated to the PU physical channel performs a received signal on the corresponding PU physical channel to obtain a plurality of signal samples, and instructs the SN to use the multiple signals. a sample, calculating local normalized energy data corresponding to the PU physical channel, and using the local normalized energy data to obtain local spectrum sensing data; using the obtained local spectrum sensing data as a channel frequency corresponding to the PU physical channel Test results;

For example, the FC instructs the SN to perform the following processing: the SN calculates a ratio of a signal average energy of the local signal sample sample to a local noise power by using a normalized energy detector, obtains local normalized energy data, and obtains the localized localized energy data, and The energy data is normalized for data processing, and finally the local spectrum sensing data is obtained.

As an implementation manner, before the SN calculates the local spectrum sensing data, the FC may also send a sensing channel allocation instruction to the multiple SNs in the coverage area of the FC by using the control channel, thereby notifying the PU physical channel to be perceived by multiple SNs in the coverage area. .

As an implementation manner, the FC may further indicate that after the SN calculates the local spectrum sensing data, Local spectrum sensing data is reported through the uplink channel.

Step 104: Determine a state of the PU physical channel according to a channel frequency detection result. As an embodiment of the step 104, the FC receives local spectrum sensing data from each SN, and performs data fusion on the PU physical channel corresponding to the SN according to the local spectrum sensing data obtained by the SN, to obtain the PU. A global spectrum-aware statistic of the physical channel; comparing the global spectrum-aware statistic of the PU physical channel with a corresponding determination threshold, to determine whether the PU physical channel is in an idle state, if the threshold is less than a corresponding threshold Then, the FC determines that the current spectrum resource is idle, that is, determines that the PU physical channel is in an idle state; otherwise, the FC determines that the current spectrum resource is occupied by the PU.

As an embodiment, when the FC determines that the state of a PU physical channel is an idle state, the information of the PU physical channel in the idle state may also be sent to all SNs in its coverage.

As an implementation manner, the data fusion may be implemented in the following manner: The FC calculates a weighting factor for fusing the local spectrum sensing data of the SN according to the number of receiving antennas of the SN, the number of signal samples, and the received signal to noise ratio. And calculating a global spectrum sensing statistic of the PU physical channel corresponding to the SN according to the local spectrum sensing data and the weighting factor of the SN.

For example, the FC receives the local spectrum sensing data reported by the SN, and allocates different weighting factors to the local spectrum sensing data of different SNs according to the number of receiving antennas of the SN, the number of signal samples, and the received signal to noise ratio, where weighting The factor is based on the local spectrum sensing data reliability allocation of the SN; the FC calculates the linear weighting of the local spectrum sensing statistic according to the weighting factor and the local spectrum sensing data of the SN received by the FC, and uses the linear weighting result as the global spectrum sensing statistic.

FIG. 2 is a flowchart of a broadband spectrum sensing method according to an embodiment of the present invention. As shown in FIG. 2, the method includes the following steps:

Step S202: The FC acquires a statistical idle probability of the PU physical channel. The statistical idle probability of the PU physical channel is the ratio of the PU physical channel idle time to the total time obtained by the long-term spectrum sensing update. The FC can obtain the statistical idle probability of the PU physical channel by periodically accessing the spectrum sensing database.

Step S204: The FC constructs a spectrum aware channel sequence list.

After obtaining the statistical idle probability of the PU physical channel, the FC sequentially ranks the statistical idle probability of the PU physical channel in descending order.

Step S206, selecting SN.

Before performing the step S206, the FC acquires the number of receiving antennas, the number of signal samples, and the received signal to noise ratio of each SN in its own coverage.

When performing the step S206, the FC selects sufficient SNs to perceive a PU physical channel according to the requirements of the system for detecting probability and false alarm probability, until the selected SNs are all allocated for sensing the PU physical channel, or all The PU physical channel has been assigned an SN.

Step S208: The FC informs the SN to perceive the channel allocation result.

Step S210: The SN acquires local spectrum sensing data.

The SN receives the signal on the spectrum-aware time-slot-aware channel (ie, the FC informs the detected PU physical channel), and uses the normalized energy detector to calculate the local spectrum-aware detection statistic (ie, localized normalized energy data). Finally, the local spectrum sensing detection statistic is processed to obtain local spectrum sensing data.

Step S212: The SN reports the local spectrum sensing data to the FC.

Step S214: The FC fuses the local spectrum sensing data of the SN.

The FC allocates different weighting factors to the local spectrum sensing data of different SNs according to the number of receiving antennas of the SN, the number of signal samples, and the received signal to noise ratio, wherein the weighting factors are allocated according to the reliability of the SN local spectrum sensing data.

The FC calculates the linear weighting of the local spectrum sensing statistic according to the weighting factor and the local spectrum sensing data of the SN received by the FC, and uses the linear weighting result as the global spectrum sensing statistic. Step S216: The FC determines the state of each PU physical channel.

The FC compares the global spectrum-aware statistic with the size of the decision threshold. If the global spectrum-aware statistic is greater than or equal to the decision threshold, the FC determines that the current spectrum resource is occupied by the PU. If the global spectrum-aware statistic is less than the decision threshold, the FC determines that the current spectrum resource is idle. That is, the corresponding PU physical channel is idle.

Step S218: The FC informs the SN of the PU physical channel that is currently idle.

The detailed description is further described below in conjunction with a specific embodiment.

Step 1: The FC acquires a statistical idle probability of the PU physical channel.

The FC accesses the spectrum sensing database through the interface with the spectrum sensing database to obtain the statistical idle probability of the PU physical channel.

Step 2: The FC constructs a spectrum-aware channel sequence list.

Based on the statistical idle probability of each PU physical channel obtained in step 1, the FC sequentially arranges the PU physical channels in descending order of statistical idle probability, and constructs a spectrum-aware channel sequence table, as shown in the following table.

Table 1

Step 3. Select SN.

According to the perceptual channel sequence table in step 2, the FC selects the SN for the PU physical channel such as CH 2 to perform spectrum sensing. This step is described in detail below.

According to the system's demand for false alarm probability and detection probability A, CH 2 sets the false alarm probability and detection probability of spectrum sensing to P _f ^l _a = P _fa , P _d ^l = P _d .

According to the number of receiving antennas of the K SNs under the FC coverage, the number of sampled signal samples, and the received signal-to-noise ratio, select any SN under the FC, and set the ith SN: if the formula (1) and Equation (2) allocates the first SN for sensing CH2, and then selects the SN of the perceived cm from the remaining SNs;

If the equations (1) and (2) are not satisfied, the FC selects any two SNs, and sets the first and the 'SNs. If the equations (3) and (4) are satisfied, the first and the SNs are used. Assigned to CH2, and then picks out the SN that senses CH1 from the remaining SNs; if equations (3) and (4) are not satisfied, then select any m (m takes values from 3 to 1), until the SN is satisfied. Equation (5) and (6), and assigning the selected m SNs to CH2, and then selecting the SNs that sense CH1 from the remaining SNs; until all PU physical channels are assigned SN or all SNs are A corresponding PU physical channel to be perceived is allocated. Where formula (1) is:

Equation (3) is:

Equation (4) is: Q ≥ P

Equation (5) is: Q

Equation (6) is Q

_{ι ι} Ν _ι γ _ι 1 1 + 2γ, ₂ 1 2

■+-

"'^ Μ,Ν, , Μ,Ν,"'^ Μ,Ν,, MlNl

Step 4: The FC informs the SN to perceive the channel allocation result. The FC transmits the perceptual channel allocation result of each SN to the SN.

Step 5: The SN acquires local spectrum sensing data.

The local spectrum sensing data acquisition step in this step is as shown in FIG. 3. First, each SN participating in the spectrum sensing performs a sampling on the corresponding sensing channel CH2. For example, the first SN passes through the root at the "first time". The antenna samples the received signal to obtain the signal sample y of xi, («); set the number of signal samples of the first SN participating in the spectrum sensing on the corresponding sensing channel CH1, and the local SN calculation The energy data is e _k ,

Where, If represents the two norm operation of the vector; second, the SN processes the local normalized energy data; finally, calculates the local spectrum sensing data.

Step 6: The SN reports the local spectrum sensing data to the FC.

The SN reports local spectrum sensing data to the FC on the uplink channel.

Step 7. The FC receives the local spectrum sensing data of the SN.

The FC receives the local spectrum sensing data reported by the SN.

Step 8. The FC fuses the local spectrum sensing data of the SN.

The FC allocates different weighting factors % to the local spectrum sensing data of different SNs according to the number of receiving antennas of the SN, the number of samples of the signal, and the received signal to noise ratio, wherein the weighting factor is based on

M N γ

The reliability of the local spectrum sensing data of the SN is allocated, ie = ^.

The FC calculates the linear weighting of the local spectrum sensing statistic according to the weighting factor and the SN local spectrum sensing data received by the FC, and uses the linear weighting result as the global spectrum sensing statistic, that is, _G = |^. Step 9. The FC determines the state of each PU physical channel.

The FC compares the obtained global spectrum sensing statistic T _G with a preset decision threshold τ. When the global spectrum sensing statistic is greater than or equal to the decision threshold, ie? When the current spectrum resource is determined to be occupied by the PU, all the SNs in the coverage of the FC cannot utilize the PU physical channel; When the global spectrum sensing statistic is less than the decision threshold, ie? "When the current spectrum resource is determined to be idle, all SNs within the coverage of the FC may utilize the PU physical channel.

Step 10. The FC informs the SN of the PU physical channel that is currently idle.

The FC informs the sensing channel corresponding to the SN in its coverage through the downlink channel.

The following is described in detail in conjunction with another specific embodiment.

The FC accesses the spectrum sensing database through the spectrum sensing interface to obtain the statistical idle probability of the 12 PU physical channels of the PU system, as shown in Table 2.

Table 2

Step 2: The FC constructs a spectrum-aware channel sequence list.

The FC sequentially arranges the PU physical channels in descending order of statistical idle probability, and constructs a list of perceptual channel sequences, as shown in Table 3.

Table 3 List of perceptual channel sequences constructed from 12 PU physical channels Channel allocation sequence channel

1 CH2

2 CH 1

3 CH5

4 CH4

5 CH7

6 CH6

7 CH9

8 CH3

9 CH 10

10 CH8

11 CH 12

12 CH 11

Step 3. Select SN.

The FC obtains the number of receiving antennas of 20 SNs in its coverage, and the number of signal samples. The received signal-to-noise ratio is shown in Table 4. Table 420 SN attribute table

mouth ,

Sensing Day Receiving Day 1§ - ^ Receiving Signal Noise Power Occupancy, Number of Lines Number of Samples Noise Ratio (dB) Rate (dBm)

SN1 4 2000 -6.3 -100

SN2 4 2000 -16.6 -100

SN3 4 2000 -6.1 -100

SN4 4 2000 -1.0 -100

SN5 4 2000 -7.3 -100

SN6 4 2000 -4.3 -100

SN7 2 1000 -6.0 -97

SN8 2 1000 -11.7 -97 SN9 2 1000 -8.4 -97

SN10 2 1000 -14.3 -97

SN11 2 1000 -5.1 -97

SN12 2 1000 -16.3 -97

SN13 2 1000 -15.9 -97

SN14 2 1000 -14.5 -97

SN15 ¹ 500 -26.2 -94

SN16 ¹ 500 -2.1 -94

SN17 ¹ 500 -8.2 -94

SN18 ¹ 500 -14.2 -94

SN19 ¹ 500 -2.5 -94

SN 20 ¹ 500 -19.4 -94

Table 4

Firstly, SN is assigned to CH 2, the upper bound of the system false alarm probability is P _fa = o.oi, the lower bound of the detection probability is P _d =0.9, the FC allocation SN4, SN6, SN3 senses CH2; the allocation SN1, SN5, SN 11 senses CHI; Allocating SN7, SN16, and SN19 to sense CH5; allocating SN9, SN2, and SN8 to perceive CH4; allocating SN17, SN10, and SN14 to perceive CH7; and allocating SN 13, SN 12, and SN 18 to perceive CH6. Since the remaining SN 15 and SN20 sensing performance cannot meet the system requirements, the spectrum sensing of SN 15 and SN 20 is no longer involved.

Step 4: The FC informs the SN to perceive the channel allocation result.

The SN3, the SN4, and the SN1 sense the CH2; the SN1, the SN5, and the SN19 sense the CH5; the SN2, the SN8, and the SN9 sense the CH4; the SN 10, the SN 14, and the SN17 sense the CH7; the SN 12, the SN 13, and the SN The SN 18 senses the CH 6; the SN 15 and the SN 20 do not participate in the spectrum sensing command and are sent to each SN through the downlink channel.

Step 5: The SN acquires local spectrum sensing data.

SN 3, SN 4, SN 6 sample the received signal on CH 2 to obtain signal samples y», y ₆ ("), y ₃ («); SN1, SN5, SN 11 receive signals on CH 1 Take a sample and get a letter No. sample y ") y ₅ ("), y _u («); SN 7, SN 16, SN 19 sample the received signal on CH 5 to obtain signal samples y ₇ ("), y ₁₆ (") y.(«); SN2, SN8, SN9 sample the received signal on CH4 to obtain signal samples y ("), y ₂ ("), y ₈ («); SN 10, SN 14, SN 17 The received signal is sampled on CH 7 to obtain signal samples y ₁₇ ("), ^. ("), y ₁₄ («); SN 12, SN 13, SN 18 sample the received signal on CH 6 , get the signal samples y ₁₃ ("), y ₁₂ ("), y ₁₈ (").

The SN calculates the local normalized energy on each PU physical channel. The normalized energies are: Σ «) Ιί ∑l (")

1x10"" χ 4 χ 2000 1x10"" x 4 x 2000

The normalized energies for 1x10"" x 4x2000 are:

1x10"" x 4 x 2000 1x10"" x 4x2000

∑ (")

1.9953 xlO" ¹³ x2xl000

The normalized energies of CH 5 are: ∑|y ₇ («)I

1.9953x10 x2xl000 3.9811x10— " xlx500

3.9811x10— ¹³ xlx500

The normalized energies of CH 4 are:

∑l (")

1x10"" x 4 x 2000 1.9953x10 x2xl000

ΣΙΜ")

1.9953x10-" x 2x1000

The normalized energies of CH 7 are: ∑ (") ∑ (")

1.9953x10-" x2xl000 1.9953x10-" x2xl000

3.9811x10— ¹³ xlx500

The normalized energies of CH 6 are:

Illy,

f f f

1.9953x10-" x2xl000 1.9953x10"" x 2x1000

3.9811x10— ¹³ xlx500

The SN processes the local normalized energy data to obtain local spectrum sensing data on each PU physical channel. Including: Each local spectrum sensing data of CH 2 is: ^{= 2} - each local frequency i of CH 1 "The perceptual data is: = ² - ^e l τ _η = e _n ² - e _n ; each local frequency i of CH 5 " The perceptual data is: K ^e ,, = - 4 - ; each local frequency i of CH 4 "sensing data is: -, T _% = el - e ₈ T ₉ = el -e ₉ . _C H 7 local frequencies i The perceptual data is: T ₁₀ = 4 - e ₁₀ T _u = 4 - e _u T ₁₇ = - e ₁₇ . The local frequencies i of _C H 6 are perceived as - ^e n ^e n T ― e ₁₃ ― e ₁₃

Step 6: The SN reports the local spectrum sensing data to the FC.

The SN reports its local spectrum sensing data that is perceived by the PU physical channel to the FC on the uplink channel. Including: local spectrum sensing data of CH 2 : τ ₃ , r ₄ τ ₆ · The local spectrum sensing data of CHI is: 本地, τ τ _η - CH 5 The local spectrum sensing data are: τ _Ί , τ ₆ , The local spectrum sensing data of τ ₁₉ · CH 4 are: Ί, r ₈ τ ₉ CH 7 The local spectrum sensing data is: . The local spectrum sensing data of 7u, r ₁₇ ; CH 6 are: , τ ₃ , τ ₁₂ .

Step 7. The FC receives the SN local spectrum sensing data.

The FC receives the local spectrum sensing data that the reported SNs perceive the PU physical channel. Including: local spectrum sensing data of CH 2 : τ ₃ , r ₄ τ ₆ · The local spectrum sensing data of CHI is: τ\, τ τ _η - CH 5 The local spectrum sensing data are: τ _Ί , τ ₆ The local spectrum sensing data of τ ₁₉ · CH4 are: τ ₂ , r ₈ τ ₉ · CH 7 The local spectrum sensing data is: . The local spectrum sensing data of T _u , τ _ΙΊ - CH 6 are: , , T _UO Step 8. The FC fuses the SN local spectrum sensing data.

The FC allocates different weighting factors to different SN local spectrum sensing data according to the number of receiving antennas of the SN, the number of signal samples, and the received signal to noise ratio. The weighting factors include: ω ₁ : = 1276.77330010737 , ω ₂ = 167.683882647733 , ω ₃ = 1317.13199989350

_{= 2454.79690055124, ω} = 1085.43485361127,} = 1705.19890277779 ω Ί = 334.388233157140, ω 8 = 119.110833707517, ω 9 = 224.257742242256

= 69.1674192295335 , ^ω η = 381.975597589946 , = 44.7848572493215

= 48.8943585928141 = 66.2606450389038 = 138.052516989946 ω ₁₇ = 58.0926927185796, ω ₁₈ = 17.6661715933536, ω ₁₉ = 132.335369023131 The FC calculates the linear weighting of the local spectrum perception statistic based on the weighting factor and the SN local spectrum sensing data received by the FC as the global spectrum sensing statistic . Includes: Global Spectrum Sensing Statistics for CH 2 ⁷ ^ ^{= β} ^ ^{+ ω} Α ^{+ ω} ^; Global Spectrum Sensing Statistics for CH 1

+ ^ω ΐΆΐ; global spectrum perceptual statistic of CH 5, , global spectrum perceptual statistic of QH 4 ⁷ ^ ^{= i3⁄4?i + i3⁄47 + fi} CH 7 global spectrum perceptual statistic, ^ω , ^Τ , ; CH 6 The global spectrum sensor statistic ^Τ °· ^{6 = ωχΐΤχ1} + ^ωγίΤγί + .

Step 9. The FC determines the state of each PU physical channel.

The FC compares the obtained global spectrum sensing statistics with a preset decision threshold τ. When the CH 2 global spectrum sensing statistic is greater than or equal to the decision threshold, that is, ≥ τ ₂ = 1. ⁶³⁴⁴⁵³ 1 ⁵ 0% 0 ²⁷ , the current spectrum resource is determined to be occupied by the PU, and all SNs in the FC coverage cannot utilize the PU physics. Channel; when the CH 2 global spectrum sensing statistic is less than the decision threshold, that is, < τ ₂ = 1. ⁶³⁴⁴⁵³ 1 ⁵ 0% 0 ²⁷ , the current spectrum resource is judged to be idle, and all SNs in the FC coverage can utilize the PU physical channel. .

When the CH 1 global spectrum sensing statistic is greater than or equal to the decision threshold, that is, = 1.1 ⁴⁵⁷ 1 ⁸ 0 ⁸⁵ 1 ⁸⁶⁴⁵ , the current spectrum resource is determined to be occupied by the PU, and the FC coverage is All SNs cannot utilize the PU physical channel; when the CH 1 global spectrum sensing statistic is less than the decision threshold, ie, rc^u^ ossi ⁸⁶⁴⁵ , the current spectrum resource is determined to be idle, and all SNs in the FC coverage can utilize the PU physics. channel.

When the CH 5 global spectrum sensing statistic is greater than or equal to the decision threshold, that is, ≥ τ ₅ =1. ⁶⁷⁹ 0 ³ 1 ²⁴⁷ 1 ⁶⁷⁹⁶ , the current spectrum resource is determined to be occupied by the PU, and all SNs in the FC coverage cannot utilize the PU physics. Channel; when the CH 5 global spectrum sensing statistic is less than the decision threshold, that is, <r ₅ =i ⁶⁷⁹ (m ²⁴⁷ i ⁶⁷⁹⁶ ), the current spectrum resource is determined to be idle, and all SNs in the FC coverage can utilize the PU physical channel.

When CH 4 global spectrum sensing statistic is larger than or equal to the decision threshold, i.e. _{_{r G4> r 4 = 0.4920040172000630 †}} , the judgment of the current spectrum resources occupied PU, all SN within the FC coverage can not use the PU physical channel; when CH 4 globally When the spectrum sensing statistic is less than the decision threshold, that is, ₄ < =0 ⁴⁹² 00 ⁴ 01 ⁷² 000 ⁶³ , the current spectrum resource is judged to be idle, and all SNs in the FC coverage can utilize the PU physical channel.

When the CH 7 global spectrum sensing statistic is greater than or equal to the decision threshold, that is, r _G7 >r ₇ =0.4762492051289690†, it is determined that the current spectrum resource is occupied by the PU, and all SNs in the FC coverage cannot utilize the PU physical channel; When the spectrum sensing statistic is smaller than the decision threshold, that is, r _G7 <r ₇ =0. ^4762492 0 ⁵ l ²⁸ % ⁹ , the current spectrum resource is judged to be idle, and all SNs in the FC coverage can utilize the PU physical channel.

When the CH 6 global spectrum sensing statistic is greater than or equal to the decision threshold, that is, r _G6 ≥ r ₆ = 0.l ^948848838875 0 ⁶ , the current spectrum resource is determined to be occupied by the PU, and all SNs in the FC coverage cannot utilize the PU physical channel. ; CH 6 global spectrum sensing when the statistic is less than the decision threshold, i.e. ^{^{94884883887506}} ₆ = 0.1, the current decision free spectrum resources, all within the FC SN coverage can use the PU physical channel.

FC will judge the current judgment of CH2, CH1, CH5, CH4, CH7, CH6. The result informs the SN within its coverage through the downlink channel.

It should be noted that the steps shown in the flowchart of the accompanying drawings may be performed in a computer system such as a set of computer executable instructions, and, although the logical order is shown in the flowchart, in some cases, The steps shown or described may be performed in an order different than that herein.

FIG. 4 is a structural block diagram of a broadband spectrum sensing system according to an embodiment of the present invention, as shown in FIG. 4, including an FC 44 and an SN 42 in its coverage;

The FC 44 is configured to obtain a statistical idle probability of the current physical channel of the primary user PU. The sensing node SN for the channel frequency detection is sequentially allocated to the PU physical channel according to the statistical idle probability. Using the SN 42, performing channel spectrum detection on the PU physical channel; determining a state of the PU physical channel according to the channel spectrum detection result;

The SN 42 is configured to perform a received signal sampling on the corresponding PU physical channel according to the allocation result of the FC 44, to obtain a plurality of signal samples, and calculate the corresponding PU physical channel by using the multiple signal sample samples. Locally normalized energy data; using the local normalized energy data to obtain local spectrum sensing data; and using the obtained local spectrum sensing data as a channel frequency detection result of the corresponding PU physical channel.

Preferably, the FC 44 is further configured to access a spectrum sensing database to obtain a statistical idle probability of all PU physical channels.

Preferably, for the current PU physical channel selected from the PU physical channel, the FC 44 is further configured to randomly select one SN 42 from the SN 42 to be allocated to allocate to the current PU physical channel, and according to the Selecting the number of receiving antennas, the number of signal samples and the received signal to noise ratio of the SN 42 to determine whether the selected SN 42 satisfies the preset false alarm probability and detection probability of the current PU physical channel;

If the judgment result is satisfied, according to the statistical idle probability in descending order, from the remaining One SN 42 is selected from the SN 42 and allocated to the next PU physical channel selected from the PU physical channel until the PU physical channel is allocated with the SN 42, and the SN 42 allocated by each of the PU physical channels is satisfied. The preset false alarm probability and detection probability of the corresponding PU physical channel;

If the result of the determination is not satisfied, the SN 42 is randomly selected according to the number of selected SNs 42 to be added until the selected SN 42 satisfies the preset false alarm probability and detection probability of the current PU physical channel.

Preferably, the FC 44 is further configured to instruct the SN 42 to receive a received signal for the corresponding PU physical channel to obtain a plurality of signal samples;

Instructing the SN 42 to calculate local normalized energy data corresponding to the PU physical channel by using the plurality of signal sample samples, and using the local normalized energy data to obtain local spectrum sensing data;

Preferably, the FC 44 is further configured to perform data fusion on the PU physical channel according to the local spectrum sensing data obtained by the SN 42 to obtain a global spectrum sensing statistic of the PU physical channel.

Preferably, the FC 44 is further configured to calculate a weighting factor for fusing the local spectrum sensing data of the SN 42 according to the number of receiving antennas, the number of signal samples, and the received signal to noise ratio of the SN 42;

Calculating a global spectrum sensing statistic of the corresponding PU physical channel according to the local spectrum sensing data of the SN 42 and the weighting factor.

FIG. 5 is a structural block diagram of an SN according to an embodiment of the present invention. As shown in FIG. 5, the SN 42 includes: The sensing channel command receiving unit 4202 is configured to receive an allocation result of the FC to the SN aware channel;

The signal sampling unit 4204 is configured to perform receiving signals on the corresponding PU physical channel according to the allocation result of the data fusion center FC, to obtain a plurality of signal samples; that is, the signal sampling unit 4204 is configured as a collection. a signal sample on the PU physical channel;

The normalized energy calculation unit 4206 is configured to calculate local normalized energy data of the corresponding PU physical channel by using the plurality of signal sample samples, that is, the normalized energy calculation unit 4206 is configured to be normalized by the same. The energy detector calculates a normalized energy of the local sample signal;

The local spectrum sensing data processing unit 4208 is configured to use the local normalized energy data to obtain local spectrum sensing data; and use the obtained local spectrum sensing data as a channel frequency detection result of the corresponding PU physical channel, that is, The local spectrum sensing data processing unit 4208 is configured to process the local normalized energy data;

The sensing data reporting unit 4210 is configured to report local spectrum sensing data.

In practical applications, the perceptual channel command receiving unit 4202, the signal sampling unit 4204, the normalized energy calculating unit 4206, the local spectrum sensing data processing unit 4208, and the sensing data reporting unit 4210 may all be implemented by a central processing unit in the SN (CPU, Central). Processing Unit), Digital Signal Processor (DSP) or Field Programmable Gate Array (FPGA).

FIG. 6 is a structural block diagram of an FC according to an embodiment of the present invention. As shown in FIG. 6, the FC 44 includes:

The database query unit 4402 is configured to obtain a statistical idle probability of all PU physical channels by querying the spectrum sensing database.

The SN allocating unit 4404 is configured to allocate a sensing node SN for channel frequency detection for each PU physical channel in descending order of statistical idle probability; that is, the SN allocating unit 4404 is configured according to system performance. It is required to allocate SN for PU physical channel for spectrum sensing; The channel frequency detection unit 4406 is configured to perform channel spectrum detection on the PU physical channel by using an SN allocated to each PU physical channel; that is, the channel spectrum detecting unit 4406 is configured to send the sensing of each SN to the SN. As a result of channel allocation, each SN performs spectrum sensing on the corresponding PU physical channel according to the allocation result;

The channel state determining unit 4408 is configured to determine the state of each PU physical channel according to the channel frequency detection result.

The statistical idle probability is a ratio of the PU physical channel idle time to the total time obtained by the long-term frequency detection.

The database query unit 4402 is further configured to access the spectrum sensing database to obtain the statistical idle probability of all current PU physical channels.

The database query unit 4402 is further configured to determine, by the frequency detection, a ratio of the PU physical channel idle time to the total time, as a statistical idle probability of the PU physical channel.

The SN allocation unit 4404 includes (not shown in Figure 4):

The channel frequency detection unit 4406 includes (not shown in Figure 4):

The channel state determining unit is further configured to: when determining that the state of a PU physical channel is an idle state, send information of the PU physical channel in an idle state to all SNs in the coverage area of the FC.

The channel state determining unit 4408 includes: a local spectrum sensing data receiving module, a data fusion module, and a decision module, where:

The local spectrum sensing data receiving module is configured to receive local spectrum sensing data reported by each SN;

The data fusion module is configured to perform data fusion according to the PU physical channel, and obtain a global spectrum sensing statistic of each PU physical channel; that is, the data fusion module is configured to allocate a weighting factor to the local spectrum sensing data reported by each SN, and according to The weighting factor calculates the linear weighting of the local spectrum sensing statistic, and uses the linear weighting result as the global spectrum sensing statistic, wherein the weighting factor is a linear function of the number of SN receiving antennas, the number of signal samples, and the received signal to noise ratio; And configured to compare the global spectrum sensing statistics of the physical channels of the PUs with the corresponding thresholds. If the global spectrum sensing statistics of a PU physical channel is smaller than the corresponding threshold, the FC determines that the PU physical channel is located. The idle state; that is, the decision module is configured to determine the spectrum sensing result of each PU physical channel.

The data fusion module includes (not shown in FIG. 4): a first calculation submodule configured to calculate a weighting factor for fusing the local spectrum sensing data of the SN according to the number of receiving antennas, the number of signal samples, and the received signal to noise ratio of the SN;

In a practical application, the database query unit 4402, the SN allocating unit 4404, the channel frequency detecting unit 4406, and the channel state determining unit 4408 may each be a central processing unit (CPU) in the SN, and a digital signal processor (DSP, Digital Signal Processor) or Field Programmable Gate Array (FPGA).

It should be noted that the database-based high-efficiency spectrum sensing device described in the device embodiment corresponds to the foregoing method embodiment, and the specific implementation process has been described in detail in the method embodiment, and is not described again in ifc.

In summary, the embodiments of the present invention have the following technical effects:

1. The CC selects a preferentially perceived PU physical channel according to the statistical idle probability of the PU physical channel of the PU system, which can improve the probability that the CRC successfully detects the idle PU physical channel, thereby improving spectrum utilization and CRC capacity, and reducing CRC search. The time of the PU physical channel spectrum hole of the PU system improves the efficiency of spectrum sensing;

2. SN uses the normalized energy detector to obtain local normalized energy data, which can effectively overcome the influence of different SN local noise power on multi-user cooperative spectrum sensing.

3. It can allocate SN to the PU physical channel according to system performance requirements for spectrum sensing, and can select an appropriate number of SNs when the system performance requirements are met, which reduces the system overhead caused by all SNs participating in spectrum sensing, and can also improve awareness. The capacity of the radio system.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of a hardware embodiment, a software embodiment, or a combination of software and hardware. Moreover, the invention can be applied to one or more of its A computer program product embodied on a computer usable storage medium (including but not limited to disk storage and optical storage, etc.) containing computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart and/or block diagrams, and combinations of flow and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general purpose computer, a special purpose computer, an embedded processor or other programmable data processing device processor to produce a machine such that a flow or a block diagram of a flow or a block diagram or A device that has multiple functions specified in the box.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

The above is only an embodiment of the present invention. It should be noted that those skilled in the art can make some improvements and refinements without departing from the principles of the embodiments of the present invention. Retouching should also be considered as the scope of protection of the embodiments of the present invention.

Claims

claims

1. A wideband spectrum sensing method, including:

The data fusion center FC obtains the statistical idle probabilities of all current primary user PU physical channels; and allocates sensing nodes SN for channel frequency detection to the PU physical channels in order according to the statistical idle probabilities from large to small;

Using the SN allocated for the PU physical channel, channel spectrum detection should be performed on the PU physical channel;

According to the channel frequency detection result, the status of the PU physical channel is determined.

2. The method according to claim 1, wherein the statistical idle probability is the ratio of the idle time of the PU physical channel obtained through spectrum detection to the total time.

3. The method according to claim 1, wherein the FC obtains the statistical idle probability of all current PU physical channels, including:

The FC accesses the spectrum sensing database to obtain the statistical idle probabilities of all current PU physical channels.

4. The method according to claim 3, wherein the SN for channel frequency detection is allocated to the PU physical channel in order according to the statistical idle probability from large to small, including:

For the current PU physical channel selected from the PU physical channel, the FC randomly selects an SN from the SNs to be allocated and assigns it to the current PU physical channel, and based on the number of receiving antennas and signals of the selected SN Based on the number of samples and the received signal-to-noise ratio, determine whether the selected SN meets the preset false alarm probability and detection probability of the current PU physical channel;

If the judgment result is satisfied, then according to the statistical idle probability order from large to small, select an SN from the remaining SNs and assign it to the next PU physical channel selected from the PU physical channel, until the PU physical channel SNs are evenly allocated, and the SN allocated to each of the PU physical channels satisfies the preset false alarm probability and detection probability of the corresponding PU physical channel; If the judgment result is not satisfied, the FC randomly selects an SN by adding one to the number of selected SNs until the selected SN meets the preset false alarm probability and detection probability of the current PU physical channel.

5. The method according to claim 4, wherein using the SN to perform channel spectrum detection on the PU physical channel includes:

Instruct the SN to sample the received signal on the corresponding PU physical channel to obtain multiple signal sampling samples;

Instruct the SN to use the multiple signal sampling samples, calculate the local normalized energy data corresponding to the PU physical channel, and use the local normalized energy data to obtain local spectrum sensing data;

The local spectrum sensing data is used as the channel frequency detection result of the corresponding PU physical channel.

6. The method according to claim 5, wherein the determining the status of the PU physical channel according to the channel frequency detection result includes:

The FC performs data fusion on the PU physical channel based on the local spectrum sensing data obtained by the SN to obtain global spectrum sensing statistics of the PU physical channel;

The global spectrum sensing statistics of the PU physical channel are compared with the decision threshold respectively. If it is less than the decision threshold, it is determined that the PU physical channel is in an idle state.

7. The method according to claim 6, wherein the correspondence performs data fusion on the PU physical channel to obtain global spectrum sensing statistics of the PU physical channel, including:

According to the number of receiving antennas, the number of signal sampling samples and the receiving signal-to-noise ratio of the SN, respectively calculate the weighting factors used to fuse the local spectrum sensing data of the SN;

According to the local spectrum sensing data of the SN and the weighting factor, the global spectrum sensing statistics of the corresponding PU physical channel are calculated.

8. The method according to any one of claims 1 to 7, wherein the method further includes: when it is determined that the state of a certain PU physical channel is an idle state, changing the PU in the idle state to Physical channel information is sent to all SNs within the coverage of the FC.

9. A data fusion center FC, the FC includes:

A database query unit configured to obtain the statistical idle probability of all current primary user PU physical channels;

The SN allocation unit is configured to allocate sensing nodes SN for channel frequency detection to the PU physical channel in order according to the statistical idle probability from large to small;

A channel frequency spectrum detection unit configured to utilize the SN to perform channel spectrum detection on the PU physical channel;

The channel status determination unit is configured to determine the status of the PU physical channel based on the channel frequency detection result.

10. The FC according to claim 9, wherein the database query unit is further configured to determine the ratio of the idle time of the PU physical channel obtained through frequency detection to the total time as the PU physical channel. The statistical idle probability of .

11. The FC according to claim 9, wherein the database query unit is further configured to access the spectrum sensing database to obtain the statistical idle probabilities of all current PU physical channels.

12. The FC according to claim 11, wherein the SN allocation unit includes: a selection module configured to randomly select one of the SNs to be allocated for the current PU physical channel selected from the PU physical channels. The SN is assigned to the current PU physical channel; the judgment module is configured to judge whether the selected SN meets the presets of the current PU physical channel based on the number of receiving antennas, the number of signal sampling samples and the receiving signal-to-noise ratio of the selected SN False alarm probability and detection probability;

If the judgment result is satisfied, the selection unit is triggered to select an SN from the remaining SNs and assign it to the next PU physical channel selected from the PU physical channel in order of statistical idle probability from large to small, until The PU physical channels are all assigned an SN, and the SN assigned to each of the PU physical channels satisfies the preset false alarm probability and detection probability of the corresponding PU physical channel; If the judgment result is not satisfied, the selection unit is triggered to randomly select an SN by adding one to the number of selected SNs until the selected SN meets the preset false alarm probability and detection probability of the current PU physical channel.

13. The FC according to claim 12, wherein the channel frequency detection unit includes: a first indication module configured to instruct the SN to sample the received signal on the corresponding PU physical channel to obtain multiple signals Take samples;

The second instruction module is configured to instruct the SN to use the multiple signal sampling samples to calculate local normalized energy data corresponding to the PU physical channel, and use the local normalized energy data to obtain local spectrum sensing data. ; Use the obtained local spectrum sensing data as the channel frequency detection result of the corresponding PU physical channel.

14. The FC according to claim 13, wherein the channel state determination unit includes: a local spectrum sensing data receiving module configured to receive local spectrum sensing data from the SN;

A data fusion module configured to perform data fusion on the PU physical channel to obtain global spectrum sensing statistics of the PU physical channel;

A decision module configured to compare the global spectrum sensing statistics of the PU physical channel with a decision threshold. If it is less than the decision threshold, it is determined that the PU physical channel is in an idle state.

15. The FC according to claim 14, wherein the data fusion module includes: a first calculation sub-module configured to calculate respectively according to the number of receiving antennas of the SN, the number of signal sampling samples and the receiving signal-to-noise ratio. A weighting factor used to fuse the local spectrum sensing data of the SN;

The second calculation submodule is configured to calculate the global spectrum sensing statistics of the corresponding PU physical channel according to the local spectrum sensing data of the SN and the weighting factor.

16. The FC according to any one of claims 9 to 15, wherein the channel status confirmation The specific unit is also configured to send the information of the PU physical channel in the idle state to all SNs within the coverage of the FC when it is determined that the state of a certain PU physical channel is in the idle state.

17. A sensing node SN, the SN includes:

The signal sampling unit is configured to sample the received signal on the corresponding PU physical channel according to the allocation result of the data fusion center FC, and obtain multiple signal sampling samples;

A normalized energy calculation unit configured to use the plurality of signals to sample samples and calculate corresponding

Local normalized energy data of PU physical channel;

The local spectrum sensing data processing unit is configured to utilize the local normalized energy data to obtain local spectrum sensing data, and use the obtained local spectrum sensing data as the channel frequency detection result of the corresponding PU physical channel.

18. A broadband spectrum sensing system, including:

The data fusion center FC is configured to obtain the statistical idle probabilities of all current primary user PU physical channels; and allocate sensing for channel frequency detection to the PU physical channels in order according to the statistical idle probabilities from large to small. Node SN; use the SN allocated for the PU physical channel to perform channel spectrum detection on the PU physical channel; determine the status of the PU physical channel according to the channel spectrum detection result;

The sensing node SN is configured to sample the received signal of the corresponding PU physical channel according to the allocation result of the FC to obtain multiple signal sampling samples; and use the multiple signal sampling samples to calculate the corresponding PU physical channel Local normalized energy data; Use the local normalized energy data to obtain local spectrum sensing data; Use the obtained local spectrum sensing data as the channel frequency detection result of the corresponding PU physical channel.

19. The broadband spectrum sensing system according to claim 18, wherein the statistical idle probability is the ratio of the PU physical channel idle time and the total time obtained through frequency detection.

20. The broadband spectrum sensing system according to claim 18, wherein the FC is further configured to access a spectrum sensing database to obtain statistical idle probabilities of all current PU physical channels.

21. The broadband spectrum sensing system according to claim 20, wherein, for the current PU physical channel selected from the PU physical channel, the FC is further configured to randomly select an SN from the SN to be allocated and assign it to The current PU physical channel, and based on the number of receiving antennas, the number of signal sampling samples and the receiving signal-to-noise ratio of the selected SN, determine whether the selected SN meets the preset false alarm probability and detection probability of the current PU physical channel;

If the judgment result is satisfied, then according to the statistical idle probability order from large to small, select an SN from the remaining SNs and assign it to the next PU physical channel selected from the PU physical channel, until the PU physical channel SNs are evenly allocated, and the SN allocated to each of the PU physical channels satisfies the preset false alarm probability and detection probability of the corresponding PU physical channel;

If the judgment result is not satisfied, SNs are randomly selected by adding one to the number of selected SNs one after another until the selected SNs meet the preset false alarm probability and detection probability of the current PU physical channel.

22. The broadband spectrum sensing system according to claim 21, wherein the FC is further configured to instruct the SN to sample the received signal on the corresponding PU physical channel to obtain multiple signal sampling samples;

The FC is also configured to use the local spectrum sensing data as the channel frequency detection result of the corresponding PU physical channel.

23. The broadband spectrum sensing system according to claim 22, wherein the FC is further configured to perform data fusion on the PU physical channel according to the local spectrum sensing data obtained by the SN to obtain the PU physical channel. Global spectrum sensing statistics of the channel;

The global spectrum sensing statistics of the PU physical channel are respectively compared with the decision threshold. If it is less than the decision threshold, it is determined that the PU physical channel is in an idle state.

24. The wideband spectrum sensing system according to claim 23, wherein the FC is further configured to respectively calculate the values for fusing the SN according to the number of receiving antennas of the SN, the number of signal sampling samples and the receiving signal-to-noise ratio. The weighting factor of the local spectrum sensing data;

25. The wideband spectrum sensing system according to any one of claims 18 to 24, wherein the FC is further configured to, when it is determined that the state of a certain PU physical channel is an idle state, The information is sent to all SNs within the coverage of the FC.

26. A computer storage medium, in which computer executable instructions are stored, and the computer executable instructions are used to execute the broadband spectrum sensing method according to any one of claims 1 to 8.