TWI542177B - A method and apparatus for spectrum switching in a perceptual radio system - Google Patents

Description

Spectrum switching method and device in cognitive radio system

The present invention relates to the field of communication technologies, and in particular, to a spectrum switching method and apparatus in a cognitive radio system.

The radio communication spectrum is a valuable natural resource. With the rapid development of wireless communication technology, the problem of poor spectrum resources is becoming more and more serious. In order to alleviate the current situation of spectrum resources, relevant departments and institutions have monitored and studied the wireless communication spectrum. It is found that certain frequency bands (such as TV bands) are not used most of the time or are not used in most areas, and some bands have multiple systems and multiple users competing at the same time, that is, the use of spectrum resources does not exist. A phenomenon of equilibrium.

The concept of Cognitive Radio (CR) is generated in this context. The basic idea is that the cognitive radio system can dynamically opportunistically monitor the changes in the current wireless environment without causing interference to the authorization system. Ground access to the white space for communication.

When the white space of the opportunistic access authorization system of the radio system is perceived, the premise is that the protection of the authorized system service is not harmful to the CR system.

For such protection, the following requirements need to be met.

(1) The ability of the cognitive radio system to accurately determine the white space spectrum of the licensed system band.

(2) Spectrum switching, that is, the CR system finds that the authorization system reappears on the currently used white space spectrum (source working frequency point), and the CR system promptly exits the currently used white space spectrum.

In order to ensure the business continuity of the CR system, the CR system should switch the entire CR system to other blank spectrum (target working frequency) to resume the service after the spectrum switching.

At present, a schematic diagram of the flow of the spectrum switching method in the cognitive radio system is shown in FIG. 1 .

On the base station side, the base station transmits a spectrum switching life to the terminal at the source working frequency point. Let the terminal stop transmitting and receiving at the source working frequency point, and then resume the cell at the new frequency point (target working frequency point). On the terminal side, after receiving the spectrum switching command, the terminal leaves the source working frequency point, performs downlink synchronization with the target working frequency point, and sends a public random access preamble (Preamble) to the target working frequency point, and then the terminal receives the target working frequency. The random access response returned by the point, including downlink resource allocation and TAC (Timing Advanced Command). The terminal sends a confirmation of the completion of the spectrum switching to the target working frequency point, and completes the spectrum switching process.

In the process of implementing the present invention, the inventors have found that at least the following problems exist in the prior art: the existing spectrum switching process is based on a static licensed band design, and the number of switching users is generally small for handover scenarios between different cells.

However, in the spectrum switching process of the cognitive radio system, all the RRC (Radio Resource Control) connected UEs (User Equipments, ie, terminals) in the entire cell need to be switched to the target working frequency, in the general cell. There are many terminals in the RRC connected state, for example, TD (Time Division, Time Division Duplex)-LTE (Long Term Evolution) system capable of supporting RRC connected state users generally has more than 1200.

The existing spectrum switching method will result in a large number of terminals concentrating on performing a contention random access procedure at a target working frequency in a short time, which may result in a higher probability of random access failure and random access delay, thereby resulting in higher The probability of spectrum switching failure and the high CR system terminal service interruption time affect the user experience of the CR system.

The present invention provides a spectrum switching method and device in a cognitive radio system to solve the problem that the existing CR system spectrum switching process may cause random access conflicts.

In order to achieve the above object, the present invention provides a spectrum switching method in a cognitive radio system, including: when a base station decision in a cognitive radio system needs to perform a spectrum switching process, the base station uses a spectrum switching command to set a target working frequency point. The dedicated random access resource information is notified to the terminal in the cognitive radio system; the base station releases the current cell at the source working frequency point, and recovers the cell at the target working frequency point; the base station and the base station The resource corresponding to the terminal through the dedicated random access resource information The source performs a non-contention random access procedure on the target working frequency point; after the non-contention random access procedure is completed, the base station receives a spectrum switching complete message sent by the terminal.

In another aspect, the present invention provides a base station for use in a cognitive radio system, comprising: a decision module, configured to determine whether a spectrum switching process needs to be performed according to a current situation; and a transmitting module for using the decision When the module decision needs to perform the spectrum switching process, the spectrum switching command is used to notify the terminal in the cognitive radio system of the dedicated random access resource information at the target working frequency point; and the processing module is used at the source working frequency point. And releasing the current cell, and recovering the cell at the target working frequency point, and performing a non-contention random access process on the target working frequency point by using the resource corresponding to the dedicated random access resource information by the terminal; The receiving module is configured to receive a spectrum switching complete message sent by the terminal after the processing module completes the non-contention random access process.

In another aspect, the present invention further provides a spectrum switching method in a cognitive radio system, comprising: receiving, by a terminal in the cognitive radio system, a spectrum switching command sent by a base station, and determining dedicated random access resource information at a target working frequency point; The terminal initiates a non-contention random access procedure to the base station at the target working frequency point by using resources corresponding to the dedicated random access resource information; when the non-contention random access process is completed The terminal sends a spectrum switching complete message to the base station.

In another aspect, the present invention further provides a terminal, which is applied to a cognitive radio system, comprising: a receiving module, configured to receive a spectrum switching command sent by a base station, and determine dedicated random access resource information at a target working frequency point; a module, configured to initiate, by using the resource corresponding to the dedicated random access resource information received by the receiving module, a non-contention random access process to the base station at the target working frequency point; After the processing module completes the non-contention random access process, The base station transmits a spectrum switching complete message.

Compared with the prior art, the present invention has at least the following advantages: by applying the technical solution proposed by the embodiment of the present invention, in the cognitive radio system, the base station specifies the target work required by the terminal in the spectrum switching process by using the spectrum switching command. A dedicated random access resource at a frequency point, the terminal performs a non-contention random access process on the target working frequency point based on the dedicated random access resource, completes uplink synchronization with the target working frequency point, and sends a spectrum switching completion message to the terminal CR system base station. Since the dedicated random access resources between different terminals are collision-free, in the spectrum switching process, after searching for the target working frequency, the terminal performs non-contention randomization by using dedicated random access resources at the target working frequency. The access process can reduce the random access failure probability and delay at the target working frequency, thereby reducing the probability of spectrum handover failure and the UE service interruption time, and improving the user experience of the CR system.

61‧‧‧Decision module

62‧‧‧Transmission module

63‧‧‧Processing module

64‧‧‧ receiving module

65‧‧‧Consultation module

71‧‧‧ receiving module

72‧‧‧Processing module

73‧‧‧Transmission module

74‧‧‧Consultation module

FIG. 1 is a schematic flowchart of a spectrum switching method in a cognitive radio system in the prior art.

2 is a schematic flow chart of a spectrum switching method in a cognitive radio system of the present invention on a base station side.

3 is a schematic flow chart of a spectrum switching method in a cognitive radio system of the present invention on a terminal side.

4 is a schematic flowchart of a spectrum switching method in a CR system in a specific application scenario of the present invention.

FIG. 5 is a schematic flowchart diagram of a spectrum switching method in a CR system according to another specific application scenario of the present invention.

Fig. 6 is a schematic structural view of a base station of the present invention.

FIG. 7 is a schematic structural diagram of a terminal according to the present invention.

As described in the background art, the existing spectrum switching method is adopted, which causes a large number of terminals to concentrate on performing a contention random access procedure on a target working frequency point in a short time, thereby causing a high probability of random access failure and random access. The delay, and thus the higher frequency spectrum handover failure probability and the higher CR system UE service interruption time, affect the user experience of the CR system.

In order to overcome such a defect, the technical solution proposed by the embodiment of the present invention is proposed. A spectrum switching method in a cognitive radio system based on a non-contention random access procedure, the main technical idea is: in the cognitive radio system, the base station specifies the target work required by the terminal in the spectrum switching process through the spectrum switching command. A dedicated random access resource at a frequency point, the terminal performs a non-contention random access process on the target working frequency point based on the dedicated random access resource, completes uplink synchronization with the target working frequency point, and sends a spectrum switching completion message to the terminal CR system base station.

The technical solution proposed by the embodiment of the present invention is applicable to an LTE system using CR technology, a TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) system, and an HSPA (High Speed Uplink Packet Access). , High Speed Uplink Packet Access) system, WCDMA (wideband Code Division Multiple Access , wideband code division multiple access), CDMA-2000 (Code Division Multiple Access-2000, CDMA -2000), GSM (Global system of Mobile communication , the entire mobile communication system ) system and other mobile communication systems.

FIG. 2 is a schematic flowchart of a spectrum switching method in a cognitive radio system of the present invention on a base station side, where the method specifically includes the following steps: Step S201: When a base station decision in a cognitive radio system needs to perform a spectrum switching process And the base station notifies, by using a spectrum switching command, the dedicated random access resource information at the target working frequency point to the terminal in the cognitive radio system.

In the actual application scenario, the processing of this step specifically includes the following two processes:

(1) The decision process of spectrum switching.

According to the difference of the specific decision basis, the process of the process is specifically: when the base station finds that the authorized user reappears at the current working frequency, or the quality of the current working frequency channel decreases, the base station determines the spectrum to be executed. Switching process.

(2) The process of generating and transmitting a spectrum switching command.

After the base station decision needs to perform the spectrum switching process, the spectrum switching command needs to be generated first, and the corresponding spectrum switching command needs to include at least the target working frequency point and the dedicated random access resource information.

The dedicated random access resource information is used to notify the terminal of the dedicated random access resource on the target working frequency point to be applied in the spectrum switching process, according to the dedicated random access. The difference in the notification manner of the resource information, the composition form of the dedicated random access resource information is further divided into the following two cases: Form 1. When the base station needs to notify the terminal of the corresponding dedicated random access resource by direct notification, the The dedicated random access resource information is specifically a dedicated random preamble sequence number and a dedicated random access time-frequency resource sequence number.

If the terminal receives the dedicated random access resource information of this form, the corresponding dedicated random preamble and the dedicated random access time-frequency resource can be directly determined.

Form 2: When the base station needs to notify the terminal of the corresponding dedicated random access resource by means of an indirect notification, the dedicated random access resource information is specifically a dedicated random access resource configuration information and a general control parameter.

The general control parameter is specifically calculated by the base station based on the UE ID of the terminal in all RRC connected states stored by itself, and the dedicated random access resource configuration information.

If the terminal receives the dedicated random access resource information in this form, it needs to perform calculation processing according to the dedicated random access resource configuration information and the general control parameters, and the UE ID of the UE, thereby determining the corresponding dedicated random preamble. And dedicated random access time-frequency resources.

It should be noted that, in order to achieve the foregoing processing effect, before the step, the base station and the terminal pre-arrange the general calculation rule of the dedicated ID resource based on the UE ID at the target working frequency in the spectrum switching process.

The base station determines the general control parameters according to the dedicated random access resources that need to be notified to the terminal, and the calculation rules used by the terminal in determining the specific dedicated random access resources according to the corresponding general control parameters are all pre-agreed General calculation rules.

In the actual processing scenario, the foregoing conventions of the general calculation rules may specifically include two agreed manners agreed by an agreement static agreement or a dynamic configuration manner.

It should be noted that the specific content and the agreed manner of the foregoing general calculation rules may be determined according to actual needs, and such changes do not affect the scope of protection of the present invention.

Further, the specific content of the UE ID may be the UE ID allocated by the terminal at the target working frequency, or may be the UE ID allocated by the terminal at the source working frequency.

Step S202, the base station releases the current cell at the source working frequency, and The target working frequency point recovers the cell.

Through such processing, the base station completes the cell spectrum switching on the network side, that is, completes the access preparation processing of the terminal spectrum switching.

Step S203: The base station and the terminal perform a non-contention random access procedure on the target working frequency point by using resources corresponding to the dedicated random access resource information.

In an actual application scenario, the process of this step includes: first, the base station receives the terminal, and sends a dedicated random access preamble to the base station on a dedicated random access time-frequency resource, where the The dedicated random access time-frequency resource and the dedicated random access preamble are information determined by the terminal according to the dedicated random access resource information.

Then, the base station sends a random access response to the terminal.

Through the above processing, the uplink synchronization process of the target working frequency point is completed, and the terminal accesses the target working frequency point through the non-contention random access process.

Step S204: After the non-contention random access procedure is completed, the base station receives a spectrum switching complete message sent by the terminal.

Correspondingly, as shown in FIG. 3, it is a schematic flowchart of the spectrum switching method in the cognitive radio system of the present invention on the terminal side, and the specific processing procedure corresponds to the processing on the base station side, and the spectrum switching sent by the terminal through the base station The command is used to determine a dedicated random access resource at a target working frequency that is required to be applied in the spectrum switching process, and the terminal performs a non-contention random access process based on the dedicated random access resource at the target working frequency, and the target is completed. Uplink synchronization of the working frequency point, and the spectrum switching completion message is sent to the CR system base station, thereby completing the spectrum switching, and switching from the source working frequency point to the target working frequency point. For the specific processing, refer to the foregoing steps S201 to S204. The description will not be repeated here.

Compared with the prior art, the technical solution of the present invention has the following advantages: by applying the technical solution of the present invention, in the cognitive radio system, the base station specifies the target working frequency of the terminal to be applied in the spectrum switching process by using the spectrum switching command. The dedicated random access resource, the terminal performs a non-contention random access process on the target working frequency point based on the dedicated random access resource, completes uplink synchronization with the target working frequency point, and sends a spectrum switching completion message to the CR system. Base station. Since the dedicated random access resources between different terminals are collision-free, in the spectrum switching process, after the terminal searches for the target working frequency, The non-contention random access process is performed by using the dedicated random access resource, which can reduce the probability and delay of random access failure at the target working frequency, thereby reducing the probability of spectrum handover failure and the service interruption time of the UE, and improving CR The user experience of the system.

The technical solutions proposed in the embodiments of the present invention are described below in conjunction with specific application scenarios.

FIG. 4 is a schematic flowchart diagram of a spectrum switching method in a CR system according to a specific application scenario of the present invention.

In the application scenario, the base station indicates the dedicated random access resource information to the terminal in a direct manner, and the method includes the following steps: Step S401: When the base station finds that the authorized user reappears at the current working frequency, or the current working frequency When the channel quality is degraded, the base station decision needs to perform a spectrum switching process to generate a spectrum switching command.

In practical applications, the spectrum switching command includes at least a target working frequency point and dedicated random access resource information.

The dedicated random access resource information may be used by the terminal to generate a dedicated random access preamble and a dedicated random access time-frequency resource at a target working frequency point in the spectrum switching process.

In this embodiment, the base station indicates the dedicated random access resource information to the terminal in a direct manner, that is, directly notifies the terminal-specific random preamble sequence number and the dedicated random access time-frequency resource sequence number through the spectrum switching command.

Therefore, the dedicated random access resource information included in the spectrum switching command generated in this step is specifically a dedicated random preamble sequence number and a dedicated random access time-frequency resource sequence number.

Step S402: The base station sends the spectrum switching command to the terminal.

After the base station sends the spectrum switching command to the terminal, step S403 is performed.

Step S403: The base station stops transmitting and receiving signals at the source operating frequency point.

Before this step, the base station has sent a spectrum switching command to the terminal at the source working frequency point to notify the terminal to stop transmitting and receiving signals at the source working frequency point. Therefore, in this step, the base station directly operates at the source operating frequency point. The cell corresponding to the terminal is released.

Step S404: The base station recovers the cell by using the target working frequency point.

In the processing of this step, the base station recovers the cell through the target working frequency point, thereby completing the spectrum switching of the cell, and preparing the terminal for access at the target working frequency point.

Step S405: After receiving the spectrum switching command, the terminal leaves the source working frequency point and performs downlink synchronization with the target working frequency point.

That is, the terminal searches for the target working frequency point according to the information of the target working frequency point included in the received spectrum switching command.

Step S406: After receiving the spectrum switching command, the terminal generates a dedicated random access resource.

According to the information type carried in the spectrum switching command generated in the foregoing step S401, the specific processing procedure in this step is: the terminal according to the dedicated random preamble sequence number and the dedicated random access included in the received spectrum switching command. The time-frequency resource sequence number determines a dedicated random access preamble and a dedicated random access time-frequency resource, respectively, thereby generating a dedicated random access resource. It should be noted that the sequence of step S405 and step S406 can be reversed, and both steps are steps performed after step S402, and steps S405 and S406 and steps S403 and S404 have no necessary sequence, and corresponding steps are performed. The addition of the serial number is for convenience of description and does not limit the scope of protection of the embodiments of the present invention.

Step S407: The terminal sends a dedicated random access preamble to the base station on the dedicated random access time-frequency resource.

That is, the terminal performs a non-contention random access procedure at the target operating frequency.

Step S408: After receiving the random access preamble sent by the terminal, the base station sends a random access response to the terminal.

Step S409: After receiving the random access response of the base station, the terminal sends a spectrum switching complete message to the base station.

FIG. 5 is a schematic flowchart diagram of a spectrum switching method in a CR system in another specific application scenario of the present invention.

In the application scenario, the base station indicates the dedicated random access resource information to the terminal in an indirect manner, and the method includes the following steps: Step S501: The base station and the terminal pre-agreed the UE ID based on the target working frequency in the spectrum switching process. General calculation rules for dedicated random access resources.

In a specific processing scenario, the manner in which the general calculation rules are agreed in this step includes but is not limited to:

(1) The base station and the terminal statically specify the general calculation rules of the terminal-specific random access resources by agreement.

(2) The base station and the terminal agree on the calculation rules of the terminal-specific random access resources through dynamic configuration.

First, the base station and the terminal pre-store a plurality of calculation rules and numbers of terminal-specific random access resources, and then the base station selects one of the calculation rules, and passes the number of the selected calculation rule through system information or terminal-specific signaling. Notify the terminal in the cell.

The specific convention of using the above-mentioned general calculation rules can be determined according to actual needs, and such changes do not affect the scope of protection of the present invention.

Step S502: When the base station finds that the authorized user reappears at the current working frequency point, or the channel quality of the current working frequency point decreases, the base station determines that the spectrum switching process needs to be performed, and then calculates the dedicated random access resource in the process of the terminal spectrum switching. A general control parameter of the rule, and a spectrum switching command is generated according to the calculated general control parameter.

In practical applications, the spectrum switching command includes at least a target working frequency point, dedicated random access resource configuration information, and general control parameters.

The foregoing general control parameter is calculated by the base station based on the UE ID of the terminal in which all RRC connected states are stored, and the dedicated random access resource configuration information.

Step S503: The base station sends the spectrum switching command to the terminal.

After the base station sends the spectrum switching command to the terminal, step S504 is performed.

Step S504: The base station stops transmitting and receiving signals at the source operating frequency point.

Before this step, the base station has sent a spectrum switching command to the terminal at the source working frequency point in step S503 to notify the terminal to stop transmitting and receiving signals at the source working frequency point. Therefore, in this step, the base station directly operates at the source operating frequency. The cell corresponding to the terminal is released.

Step S505: The base station recovers the cell by using the target working frequency point.

In the processing of this step, the base station recovers the cell through the target working frequency point, thereby completing the spectrum switching of the cell, and preparing the terminal for access at the target working frequency point.

Step S506: After receiving the spectrum switching command, the terminal leaves the source working frequency point and performs downlink synchronization with the target working frequency point.

That is, the terminal searches for the target working frequency point according to the information of the target working frequency point included in the received spectrum switching command.

Step S507: After receiving the spectrum switching command, the terminal uses the general calculation rule defined in step S501 to select the dedicated random access resource configuration information and the general control parameter included in the spectrum switching command, and combine with the UE ID of the terminal itself. Corresponding dedicated random access resources.

The dedicated random access resource includes a dedicated random access preamble and a dedicated random access time-frequency resource.

For details, the detailed process of generating the dedicated random access resource is described in the following embodiments of the present invention, and details are not described herein again.

It should be noted that the sequence of step S506 and step S507 can be reversed, and both steps are steps performed after step S503, and steps S506 and S507 and steps S504 and S505 have no necessary sequence, and corresponding steps are performed. The addition of the serial number is for convenience of description and does not limit the scope of protection of the embodiments of the present invention.

Step S508: The terminal sends a dedicated random access preamble to the base station on the dedicated random access time-frequency resource.

That is, the terminal performs a non-contention random access procedure at the target operating frequency.

Step S509: After receiving the random access preamble sent by the terminal, the base station sends a random access response to the terminal.

Step S510: After receiving the random access response of the base station, the terminal sends a spectrum switching complete message to the base station.

It should be noted that the specific forms of the UE ID mentioned in the foregoing steps S501, S502, and S507 include, but are not limited to, the following forms:

Form 1. The UE ID assigned by the terminal at the target working frequency, such as C-RNTI (Cell Radio Network Temporary Identifier).

Form 2: The UE ID allocated by the terminal at the source working frequency, such as C-RNTI.

It should be further noted that, in the foregoing steps S501, S502, S203, and S507, the general calculation rule of the dedicated random access resource and its general control parameters need to satisfy the dedicated random access resources selected by the terminals with different UE IDs. Different requirements.

It should be noted that, in the CR system, for the method of indirectly specifying the terminal spectrum switching dedicated random access resource by using the base station, the calculation rules, configuration, and control parameters of the dedicated random access resources of each terminal in the cell are universal. Can use a community public The spectrum switching command triggers all the terminals in the cell to complete the spectrum switching process, thereby further reducing the spectrum switching command transmission delay, reducing the spectrum return time of the CR system and the terminal service interruption time, and simultaneously satisfying the authorized user interference protection and the CR system service continuity. Sexual requirements.

Hereinafter, the present invention describes a general calculation rule of a CR system dedicated random access resource and an implementation manner of related control parameter information by the following embodiments.

Specifically, this embodiment describes a general calculation rule of a dedicated random access resource and a implementation form of a general control parameter in a UE ID-based spectrum switching process in an LTE system by using a specific processing procedure in the LTE system.

In the LTE system, the used UE ID may be a C-RNTI, and the random access preamble may be a preamble code, and the random access time-frequency resource may be a PRACH (Physical Random Access Channel) resource.

First, the CR system sorts the PRACH channels of the system frames No. 0 to SFN _max and sequentially numbers them.

The SFN _max is the largest System Frame Number (SFN).

The principles of sorting include the following aspects:

(1) Arrange the PRACH channels according to the system frame number.

(2) When there are PRACH channels of the same system frame number, they are arranged according to the starting subframe number.

(3) When the PRACH channels of the same system frame number also have the same starting subframe number, they are arranged according to the frequency domain mapping position.

The PRACH channel is the minimum time-frequency resource unit required for the CR system terminal to perform a random access procedure. The PRACH channel number is n _PRACH , and the total number of PRACH channels of the system frames 0 to SFN _max is N _PRACH . Then n _{PRACH (0,1, ..., N PRACH)} .

After completing the above sorting and numbering operations, the CR system numbers the dedicated random access preambles (Dedicated Preambles).

Suppose the dedicated random access preamble number is n _{Dedicated Preamble} , and the total number of dedicated random access preambles is N _{Dedicated Preamble} , then n _{Dedicated Preamble} (0,1,..., N _{Dedicated Preamble} ).

The principle of numbering the dedicated random access preamble is that the dedicated random access preamble number is consecutive and corresponds to the dedicated random access preamble one-to-one.

In a practical implementation, a simple implementation manner is to sequentially number the dedicated random access preambles in the dedicated random access preamble set in the spectrum switching command.

Based on the above processing results, the description of the specific processing flow is performed in conjunction with the aforementioned steps.

In the foregoing step S501, the base station and the terminal statically specify a general calculation rule of the C-RNTI-based dedicated random access resource at the target working frequency in the spectrum switching process as follows: the terminal in the cell first according to the dedicated random access The total number of pilot codes N _{Dedicated Preamble} and dedicated random access resource control parameters (for example, RA period, ie RA_Cycle), combined with its own C-RNTI, calculate the dedicated random access resources of the terminal, including the dedicated PRACH channel number n _PRACH and dedicated Random access preamble number n _{Dedicated Preamble} constraints, the corresponding calculation formula is as follows: n _{Dedicated Preamble} = C-RNTI mod N _{Dedicated Preamble} .

The N _{Dedicated Preamble} and the control parameters (for example, the RA period, that is, RA_Cycle) of the dedicated random access pilot code of the terminal are respectively obtained by using the dedicated random access resource configuration parameter and the control parameter information included in the spectrum switching command.

Then, the terminal needs to select a random access resource according to the dedicated random access resource constraint calculated in the previous step: wherein the dedicated PRACH channel (that is, the foregoing dedicated random access time-frequency resource) is the earliest available PRACH whose number meets the constraint condition. The channel, and the dedicated random access preamble is a random access preamble whose number satisfies the constraint.

The above content is a general calculation rule for the terminal-specific random access resource to be statically specified by the base station and the terminal in step S501.

In step S502, the dedicated random access resource configuration information of the CR system is a dedicated random access pilot code set, and the general control parameter of the dedicated random access resource is a RA period (RA_Cycle).

A specific terminal performs only random access based on dedicated random access resources in one RA period.

The base station mentioned in step S502 calculates a dedicated random access resource based on the UE ID (C-RNTI information) of the terminal it stores and the dedicated random access resource configuration information (dedicated random access pilot code set). The general control parameters (RA period RA_Cycle) are as follows: The N _{Dedicated Preamble} is the total number of dedicated random access pilot codes.

Through the above processing, the base station calculates a general control parameter (RA period RA_Cycle) of the dedicated random access resource, and generates a dedicated random access resource configuration information (a dedicated random access pilot code set) including the target working frequency point, and Spectrum switching command for general control parameters (RA period RA_Cycle).

In step S503, the base station sends the spectrum switching command generated in step S502 to the CR system terminal, and the structure of the corresponding spectrum switching command is as described in Table 1.

In an actual application scenario, the foregoing spectrum switching command may further include radio resource configuration information of a target working frequency point. Of course, such information is not required. If the radio frequency resource configuration message is not included in the spectrum switching command, the terminal The radio resource configuration on the source frequency point can be utilized as the radio resource configuration on its target frequency point.

In step S507, after receiving the spectrum switching command, the CR system terminal uses the dedicated random access resource configuration information (dedicated random access pilot code set) and the general control parameter (RA period RA_Cycle) included in the spectrum switching command, and The specific dedicated random access resource is selected according to the UE's own UE ID (C-RNTI), and the specific implementation steps include:

(1) The terminal receives the spectrum switching command, and stores the dedicated random access resource configuration information (dedicated Random access pilot code set) and general control parameters (RA period RA_Cycle).

(2) The terminal calculates the total number of dedicated random access pilot codes in the dedicated random access pilot code set N _{Dedicated Preamble} .

(3) The terminal uses the pre-agreed calculation rule in step S501 to calculate a dedicated random connection according to the total number of dedicated random access pilot codes N _{Dedicated Preamble} and dedicated random access resource control information (RA period RA_Cycle) combined with its C-RNTI. Incoming resources, including its dedicated random access preamble and dedicated random access PRACH time-frequency resources.

Compared with the prior art, the technical solution proposed by the embodiment of the present invention has the following advantages: by applying the technical solution proposed by the embodiment of the present invention, in the cognitive radio system, the base station specifies the terminal in the spectrum switching process by using the spectrum switching command. A dedicated random access resource at a target operating frequency point to be applied, the terminal performs a non-contention random access process on the target working frequency point based on the dedicated random access resource, and completes uplink synchronization with the target working frequency point, and The spectrum switching completion message is sent to the CR system base station. Since the dedicated random access resources between different terminals are collision-free, in the spectrum switching process, after searching for the target working frequency, the terminal performs non-contention randomization by using dedicated random access resources at the target working frequency. The access process can reduce the random access failure probability and delay at the target working frequency, thereby reducing the probability of spectrum handover failure and the UE service interruption time, and improving the user experience of the CR system.

In order to implement the technical solution of the embodiment of the present invention, an embodiment of the present invention further provides a base station, which is applied to a cognitive radio system, and a schematic structural diagram thereof is shown in FIG. 6, and at least includes: a decision module 61, configured to use the current situation. And determining whether the spectrum switching process needs to be performed; the sending module 62 is configured to notify, by using the spectrum switching command, the dedicated random access resource information at the target working frequency point when the decision module 61 determines that the spectrum switching process needs to be performed. And the processing module 63 is configured to perform a non-contention random access process on the target working frequency point with the resource corresponding to the terminal through the dedicated random access resource information. The receiving module 64 is configured to receive the spectrum switching complete message sent by the terminal after the processing module 63 completes the non-contention random access process.

In a specific processing scenario, the decision module 61 is specifically configured to authorize the user to reappear at the current working frequency, or when the current working frequency channel quality is degraded, the decision needs to perform a spectrum switching process; the sending module 62. The method is specifically configured to generate a spectrum switching command and send the signal to the terminal, where the spectrum switching command includes at least a target working frequency point and dedicated random access resource information.

In another specific application scenario, the processing module 63 is specifically configured to: receive, by the terminal, a dedicated random access preamble to the base station on a dedicated random access time-frequency resource, and send the dedicated random access preamble to the base station The terminal sends a random access response, where the dedicated random access time-frequency resource and the dedicated random access preamble are information determined by the terminal according to the dedicated random access resource information.

It should be noted that, in response to the foregoing application scenario that indirectly informs the terminal of the dedicated random access resource, the foregoing base station further includes an appointment module 65, before the decision module 61 decides that the spectrum switching process needs to be performed. And pre-arranging, with the terminal, a general calculation rule of a dedicated random access resource based on the UE ID at a target working frequency in the spectrum switching process.

On the other hand, the embodiment of the present invention further provides a terminal, which is applied to a cognitive radio system, and a schematic structural diagram thereof is shown in FIG. 7 , which specifically includes: a receiving module 71, configured to receive a spectrum switching command sent by the base station, and determine Dedicated random access resource information on the target working frequency; the processing module 72 is configured to use the resource corresponding to the dedicated random access resource information received by the receiving module 71 at the target working frequency A non-contention random access procedure is initiated to the base station; and the sending module 73 is configured to send a spectrum switching complete message to the base station after the processing module 72 completes the non-contention random access procedure.

In a specific processing scenario, the receiving module 71 is specifically configured to: receive a spectrum switching command sent by the base station, where the spectrum switching command includes at least a target working frequency point, and dedicated random access resource information; Determining the dedicated random access resource information at the target working frequency point according to the information carried in the spectrum switching command.

In an actual application scenario, the processing module 72 is specifically configured to: Determining a dedicated random access time-frequency resource and a dedicated random access preamble according to the dedicated random access resource information; transmitting a dedicated random access preamble to the base station on the dedicated random access time-frequency resource; receiving the The random access response sent by the base station.

It is to be noted that, in response to the foregoing application scenario that indirectly informs the terminal of the dedicated random access resource, the terminal further includes an appointment module 74, configured to receive, by the receiving module 71, the spectrum sent by the base station. Before the handover command, the base station pre-arranges a general calculation rule of the UE ID-based dedicated random access resource at the target working frequency in the spectrum switching process.

Compared with the prior art, the technical solution proposed by the embodiment of the present invention has the following advantages: by applying the technical solution proposed by the embodiment of the present invention, in the cognitive radio system, the base station specifies the terminal in the spectrum switching process by using the spectrum switching command. A dedicated random access resource at a target operating frequency point to be applied, the terminal performs a non-contention random access process on the target working frequency point based on the dedicated random access resource, and completes uplink synchronization with the target working frequency point, and The spectrum switching completion message is sent to the CR system base station. Since the dedicated random access resources between different terminals are collision-free, in the spectrum switching process, after searching for the target working frequency, the terminal performs non-contention randomization by using dedicated random access resources at the target working frequency. The access process can reduce the random access failure probability and delay at the target working frequency, thereby reducing the probability of spectrum handover failure and the UE service interruption time, and improving the user experience of the CR system.

Through the description of the above embodiments, those skilled in the art can clearly understand that the embodiments of the present invention can be implemented by hardware, and can also be implemented by means of a software plus a necessary general hardware platform. Based on the understanding, the technical solution of the embodiment of the present invention may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (which may be a CD-ROM, a USB flash drive, a mobile hard disk, etc.). The method includes a plurality of instructions for causing a computer device (which may be a personal computer, a server, or a network side device, etc.) to perform the method described in various implementation scenarios of the embodiments of the present invention.

A person skilled in the art can understand that the drawings are only a schematic diagram of a preferred implementation scenario, and the modules or processes in the drawings are not necessarily required to implement the embodiments of the present invention.

A person skilled in the art may understand that the modules in the device in the implementation scenario may be distributed in the device that implements the scenario according to the implementation scenario description, or may be correspondingly changed in one or more devices different from the implementation scenario. The modules of the above implementation scenarios may be combined into one module, or may be further split into multiple sub-modules.

The serial numbers of the embodiments of the present invention are merely for the description, and do not represent the advantages and disadvantages of the implementation scenarios.

The foregoing disclosure is only a few specific implementation scenarios of the embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be considered by those skilled in the art should fall within the scope of the business limitation of the embodiments of the present invention. .

Claims (22)

A spectrum switching method in a cognitive radio system, comprising: when a base station decision in a cognitive radio system needs to perform a spectrum switching process, the base station uses a spectrum switching command to set a dedicated random access resource information at a target working frequency point. Notifying the terminal in the cognitive radio system; the base station releases the current cell at the source working frequency point, and recovers the cell at the target working frequency point; the base station and the terminal pass the dedicated random access The resource corresponding to the resource information performs a non-contention random access procedure on the target working frequency point; after the non-contention random access procedure is completed, the base station receives the spectrum switching complete message sent by the terminal. The spectrum switching method in the cognitive radio system according to claim 1, wherein when the base station decision in the cognitive radio system needs to perform a spectrum switching process, the base station transmits the target working frequency by using a spectrum switching command. Notifying the terminal in the cognitive radio system to the terminal in the cognitive radio system, the method includes: when the base station decision in the cognitive radio system needs to perform a spectrum switching process, the base station generates a spectrum switching command and sends the command to the base station The terminal, the spectrum switching command includes at least a target working frequency point, and dedicated random access resource information. The spectrum switching method in the cognitive radio system according to claim 2, wherein the dedicated random access resource information is specifically: a dedicated random preamble sequence number and a dedicated random access time-frequency resource sequence number; or Dedicated random access resource configuration information and general control parameters. The spectrum switching method in the cognitive radio system according to claim 3, wherein the general control parameter is specifically: The base station calculates the cell identity UE ID of the terminal in the RRC connected state and the dedicated random access resource configuration information based on all the radio resources stored by the base station. The spectrum switching method in the cognitive radio system according to claim 3, wherein when the dedicated random access resource information, specifically the dedicated random access resource configuration information and the general control parameter, the base station Before the decision to perform the spectrum switching process, the method further includes: the base station and the terminal pre-arranging a general calculation rule of the UE ID-based dedicated random access resource at the target working frequency in the spectrum switching process. The spectrum switching method in the cognitive radio system according to claim 5, wherein the base station and the terminal pre-arrange the UE ID-based dedicated random access resource at the target working frequency in the spectrum switching process. The general way of calculating rules, specifically through the agreement static agreement, or through dynamic configuration. The spectrum switching method in the cognitive radio system according to any one of the preceding claims, wherein the UE ID specifically includes: a UE ID allocated by the terminal at a target operating frequency; or The UE ID allocated by the terminal at the source operating frequency point. A base station is applied to a cognitive radio system, comprising: a decision module, configured to determine whether a spectrum switching process needs to be performed according to a current situation; and a sending module, configured to: when the decision module needs to perform a spectrum switching process And, by using a spectrum switching command, notifying the dedicated random access resource information on the target working frequency point to the terminal in the cognitive radio system; the processing module is configured to release the current cell at the source working frequency point, and at the target Recovering the cell at the working frequency point, and performing a non-contention random access process on the target working frequency point with the resource corresponding to the dedicated random access resource information by the terminal; After the processing module completes the non-contention random access process, the receiving station The spectrum switching completion message sent by the terminal. The base station according to claim 8, wherein the sending module is configured to: when the decision module needs to perform a spectrum switching process, generate a spectrum switching command and send the command to the terminal, The spectrum switching command includes at least a target working frequency point and dedicated random access resource information. According to the base station of claim 8, wherein the base module further includes: an appointment module, configured to: pre-arrange the target work in the spectrum switching process with the terminal before the decision module needs to perform the spectrum switching process; A general calculation rule for a dedicated random access resource based on UE ID at a frequency point. A spectrum switching method in a cognitive radio system, comprising: receiving, by a terminal in the cognitive radio system, a spectrum switching command sent by a base station, and determining dedicated random access resource information at a target working frequency point; And the resource corresponding to the random access resource information initiates a non-contention random access procedure to the base station at the target working frequency; when the non-contention random access process is completed, the terminal sends the base to the base The station sends a spectrum switch completion message. The spectrum switching method in the cognitive radio system according to claim 11, wherein the terminal in the cognitive radio system receives a spectrum switching command sent by the base station, and determines a dedicated random access resource at the target working frequency point. The information includes: the terminal receiving a spectrum switching command sent by the base station, where the spectrum switching command includes at least a target working frequency point and dedicated random access resource information; and the terminal is configured according to the spectrum switching command. The information carried is used to determine the dedicated random access resource information at the target working frequency. The spectrum switching party in the cognitive radio system according to claim 11 or 12 of the patent application scope The method, where the dedicated random access resource information is specifically: a dedicated random preamble sequence number and a dedicated random access time-frequency resource sequence number; or, a dedicated random access resource configuration information and a general control parameter. According to the spectrum switching method in the cognitive radio system of claim 13, the universal control parameter is specifically: the UE ID of the terminal in which all the RRC connected states are stored by the base station, and the dedicated random connection Calculated by entering the resource configuration information. The spectrum switching method in the cognitive radio system according to claim 13, wherein when the dedicated random access resource information, specifically the dedicated random access resource configuration information and the general control parameter, the terminal receives Before the spectrum switching command sent by the base station, the method further includes: the terminal and the base station pre-arranging a general calculation rule of a dedicated random access resource based on the UE ID at a target working frequency in the spectrum switching process. The spectrum switching method in the cognitive radio system according to claim 15, wherein the terminal and the base station pre-agreed a dedicated random access resource based on the UE ID at a target working frequency in the spectrum switching process. The general way of calculating rules, specifically through the agreement static agreement, or through dynamic configuration. The spectrum switching method in the cognitive radio system according to claim 14, wherein the UE ID specifically includes: a UE ID allocated by the terminal at a target working frequency; or the terminal is at a source The UE ID assigned at the working frequency. The method for spectrum switching in a cognitive radio system according to claim 15, wherein the UE ID specifically includes: a UE ID allocated by the terminal at a target working frequency; or The UE ID assigned by the terminal at the source operating frequency point. The method for spectrum switching in a cognitive radio system according to claim 16, wherein the UE ID specifically includes: a UE ID allocated by the terminal at a target working frequency; or the terminal is at a source The UE ID assigned at the working frequency. A terminal is applied to a cognitive radio system, comprising: a receiving module, configured to receive a spectrum switching command sent by a base station, and determine dedicated random access resource information at a target working frequency point; and a processing module, configured to The resource corresponding to the dedicated random access resource information received by the receiving module initiates a non-contention random access process to the base station at the target working frequency point; and a sending module is used in the processing mode After completing the non-contention random access procedure, the group sends a spectrum switching complete message to the base station. The terminal according to claim 20, wherein the receiving module is specifically configured to: receive a spectrum switching command sent by the base station, where the spectrum switching command includes at least a target working frequency point, and a dedicated Random access resource information; determining dedicated random access resource information at a target working frequency point according to information carried in the spectrum switching command. The terminal according to claim 20, further comprising an appointment module, configured to: pre-arrange a spectrum switching with the base station before the receiving module receives the spectrum switching command sent by the base station A general calculation rule for a dedicated random access resource based on UE ID at a target working frequency point in the process.