CN110572222B

CN110572222B - Filter-based method and system for identifying BCCH carrier in GSM carrier

Info

Publication number: CN110572222B
Application number: CN201910672795.3A
Authority: CN
Inventors: 曹永福; 杨剑锋; 翟海莹
Original assignee: Zhejiang Sunwave Communications Technology Co Ltd
Current assignee: Zhejiang Sunwave Communications Technology Co Ltd
Priority date: 2019-07-24
Filing date: 2019-07-24
Publication date: 2022-02-11
Anticipated expiration: 2039-07-24
Also published as: CN110572222A

Abstract

The application relates to a method and a system for identifying BCCH carriers in GSM carriers based on a filter. The method comprises the following steps: constructing at least one set of filters with an association relationship, wherein the set of filters at least comprises a first filter and a second filter; searching all GSM carriers through the first filter and the second filter; and acquiring a first output power of the first filter and a second output power of the second filter under each GSM carrier, judging whether the power fluctuation of the first output power in the preset time is less than a preset fluctuation threshold value or not according to the fact that the difference value of the second output power and the first output power is less than a first preset threshold value in the preset time, so as to carry out joint judgment, and determining whether the current GSM carrier contains BCCH (broadcast control channel) carriers or not according to the joint judgment result. The method can simply and efficiently identify the BCCH carrier wave in the GSM carrier wave, and has good timeliness.

Description

Filter-based method and system for identifying BCCH carrier in GSM carrier

Technical Field

The present application relates to the field of electronic communications technologies, and in particular, to a filter-based method and system for identifying BCCH carriers in GSM carriers.

Background

GSM is a short term for Global System for Mobile communications (Global System for Mobile communications), a digital Mobile communications standard developed by the european telecommunications standards institute ETSI. For GSM system, a frequency correction channel (FCCH for short), a synchronization channel (SCH for short), and a broadcast control channel (BCCH for short) are combined into a multiframe for transmission, and fig. 1 is a multiframe structure diagram of a common control channel continuously transmitted on a BCCH carrier frequency of a GSM system in the prior art. As shown in fig. 1, the FCCH and SCH are transmitted 5 times per 51-multiframe, and the BCCH channel is transmitted 1 time per 51-multiframe, including 4 BCCH bursts.

The invention patent with application number CN200910180162.7 discloses a frequency search method and device, for detection of FCCH channel, in order to prevent false detection and missing detection, a method of multiple detection is adopted, i.e. only if N FCCH channels are successfully detected, it is determined that FCCH channel detection is successful, and the larger N is obtained, the smaller the probability of false alarm is. In order to prevent the detection from being missed, the RSSI mean threshold cannot be set too large, and is generally set in the range of-95 dBm to-105 dBm. This may result in an excessively long detection time. In the BCH channel combination type, 1 frame in every 10 frames in 51 multiframes is an FCCH, and the last frame of 51 multiframes is an idle frame, so for data of a certain frequency point, as long as the RSSI average value of the first frame data is less than the threshold RSSI _ Th, FCCH detection of at least 10 × N + floor (N/5) (floor represents rounding operation) multiframes is performed, and assuming that N is 5, detection of at least 51 multiframes is performed.

The invention patent with application number CN201210168754.9 discloses a GSM frequency offset estimation method and system, comprising the steps of: searching all GSM carrier frequencies; locking the carrier frequency with the maximum average power, and searching the FCCH channel by using an autocorrelation algorithm in the carrier frequency with the maximum average power; if the FCCH channel searching is successful, extracting FCCH channel signals, if the FCCH channel searching is unsuccessful, locking a next carrier frequency according to the sequence of average power from large to small, searching the FCCH channel in the locked carrier frequency until the FCCH channel searching is successful, and extracting the FCCH channel signals; and performing frequency offset estimation according to the extracted FCCH channel signal. This method requires searching using an autocorrelation identification algorithm, requires a large amount of calculated autocorrelation values to be stored, results in an excessively large amount of memory and computation, and is inefficient in timeliness.

Disclosure of Invention

In view of the foregoing, there is a need to provide a method and system for identifying BCCH carriers in GSM carriers based on filters, which is simple, fast and time-efficient.

A method of filter-based identification of BCCH carriers in GSM carriers, the method comprising:

constructing at least one set of filters with an association relationship, wherein the set of filters at least comprises a first filter and a second filter;

searching all GSM carriers through the first filter and the second filter;

acquiring first output power of the first filter and second output power of the second filter under each GSM carrier, judging whether power fluctuation of the first output power in preset time is smaller than a preset fluctuation threshold value or not according to the fact that the difference value of the second output power and the first output power is smaller than a first preset threshold value in preset time, carrying out combined judgment, and determining whether the current GSM carrier contains BCCH carriers or not according to a combined judgment result.

In one embodiment, the constructing at least one set of filters having an association relationship, the set of filters including at least a first filter and a second filter, includes:

setting the center frequency and the working bandwidth of the first filter;

setting the center frequency and the working bandwidth of the second filter;

the center frequency of the first filter is higher than the center frequency of the second filter.

In one embodiment, the setting the center frequency and the operating bandwidth of the second filter includes:

setting the center frequency of the second filter as the center frequency of a standard GSM carrier;

the working bandwidth of the second filter is set to be 180 KHz-200 KHz.

In one embodiment, the setting the center frequency and the operating bandwidth of the first filter includes:

setting the central frequency of the first filter to be 61 KHz-74 KHz higher than that of the second filter, wherein the numerical range of 61 KHz-74 KHz comprises two endpoints;

the working bandwidth of the first filter is set to be 10 KHz-20 KHz.

In one embodiment, the center frequency of the first filter is 67.708KHz higher than the center frequency of the second filter.

In one embodiment, the searching for all GSM carriers by the first filter and the second filter includes:

and carrying out polling search on the GSM carrier one by one through the first filter and the second filter according to the channel arrangement rule of the GSM carrier.

In one embodiment, the determining, in a preset time, whether a power fluctuation of the first output power in the preset time is smaller than a preset fluctuation threshold according to that a difference between the second output power and the first output power is smaller than a first preset threshold, so as to perform a joint decision, and determining whether a current GSM carrier includes a BCCH carrier according to a joint decision result includes:

judging whether the difference value between the second output power and the first output power is smaller than a first preset threshold value at any time interval within preset time;

if the difference value between the second output power and the first output power is smaller than a first preset threshold value, judging whether the power fluctuation of the first output power in preset time is smaller than a preset fluctuation threshold value;

and if the power fluctuation of the first output power in the preset time is smaller than a preset fluctuation threshold value, determining that the current GSM carrier contains the BCCH carrier.

In one embodiment, the method further comprises:

after continuously searching the TDMA frame periods of 11 GSM carriers, if the difference value between the second output power and the first output power is not smaller than a first preset threshold value and the power fluctuation of the first output power is not smaller than a preset fluctuation threshold value, determining that the current GSM carrier does not contain the BCCH carrier.

In one embodiment, the method further comprises:

constructing a plurality of sets of related first filters and second filters by using the FPGA;

and searching the GSM carrier through a plurality of sets of the first filter and the second filter according to the channel arrangement rule of the GSM carrier.

Correspondingly, the invention also provides a filter-based identification device for the BCCH carrier in the GSM carrier, which comprises a construction module, a search module and a judgment module:

the construction module is used for constructing at least one set of filters with correlation, and the set of filters at least comprises a first filter and a second filter;

the searching module is used for searching all GSM carriers through the first filter and the second filter;

the judgment module is used for acquiring the first output power of the first filter and the second output power of the second filter under each GSM carrier, judging whether the power fluctuation of the first output power in the preset time is smaller than a preset fluctuation threshold value or not according to the fact that the difference value of the second output power and the first output power is smaller than a first preset threshold value in the preset time so as to carry out combined judgment, and determining whether the current GSM carrier contains BCCH carriers or not according to the combined judgment result.

Correspondingly, the invention also provides computer equipment, which comprises a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to realize the following steps;

searching all GSM carriers through the first filter and the second filter;

Accordingly, the present invention also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of;

searching all GSM carriers through the first filter and the second filter;

The method and the system for identifying the BCCH carrier in the GSM carrier based on the filter do not relate to a complex algorithm, and all the GSM carriers are searched by using the constructed first filter and the second filter; acquiring first output power of a first filter and second output power of a second filter under each GSM carrier; judging whether the power fluctuation of the first output power in the preset time is less than a preset fluctuation threshold value or not according to the fact that the difference value of the second output power and the first output power is less than a first preset threshold value in the preset time so as to carry out combined judgment, and directly determining whether the current GSM carrier contains BCCH carrier waves or not according to the combined judgment result; therefore, the BCCH carrier wave identification in the GSM carrier wave can be simply and efficiently completed, and the method has good timeliness.

Drawings

Fig. 1 is a multi-frame structure diagram of a common control channel continuously transmitted on a BCCH carrier frequency of a GSM system in the prior art;

fig. 2 is a flow diagram of a method for identifying BCCH carriers in filter-based GSM carriers in one embodiment;

FIG. 3 is a schematic flowchart of step S300 in FIG. 2;

fig. 4 is a block diagram of an identification device with a BCCH carrier in a filter-based GSM carrier in one embodiment;

FIG. 5 is a diagram illustrating an internal structure of a computer device according to an embodiment.

In the figure: 100. building a module; 200. a search module; 300. and a decision module.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In one embodiment, as shown in fig. 2, there is provided a filter-based method for identifying BCCH carriers in GSM carriers, comprising the steps of:

s100, constructing at least one set of filters with correlation, wherein the set of filters at least comprises a first filter and a second filter.

Specifically, the set of filters having the association relationship is constructed by setting parameters associated with each other for a first filter and a second filter in the set of filters. That is, the first filter and the second filter are both a set for searching all GSM carriers; the first filter and the second filter are suitable for a shielding system, a repeater system, a base station scanning and searching system and other scenes. The first filter and the second filter specific parameters may be constructed differently for different application scenarios. In other embodiments, the number of filters in a set of filters may be more than two, and is not limited thereto.

In one embodiment, the set of filters includes three filters, namely, a first filter, a second filter and a third filter; and the third filter is used for working when the base station signal is less than or equal to-95 dBm so that the incoming noise floor is small, and the filter set can continuously and stably operate. The operating bandwidth of the third filter may be 3 KHz.

And S200, searching all GSM carriers through the first filter and the second filter.

Specifically, the GSM carrier is transmitted by the base station. And searching all GSM carriers one by one from top to bottom according to the channel arrangement rule according to the first filter and the second filter constructed in the step S100. And in each search, the first filter and the second filter both receive the same GSM carrier data, and filter and output the carrier data independently. After continuously searching the TDMA frame period of 11 GSM carriers, if the condition of coincidence does not occur in the time period (the difference value between the second output power and the first output power is less than a first preset threshold value and the power fluctuation of the first output power in a preset time is less than a preset fluctuation threshold value), the first filter and the second filter are switched to the unsearched GSM carriers until the search of the GSM carriers of all the bands is finished. If the conditions are met, performing secondary confirmation according to the appearing time interval (4 times in 51 frames are 10 frame intervals, and one time is 11 frame intervals) of the FCCH of the BCCH carrier; and switching to the unsearched GSM carrier after confirmation until the search of the GSM carriers of all bands is finished. A typical GSM frame refers to a TDMA frame with a period of 4.615 milliseconds, and a control frame is 51 TDMA frames.

S300, acquiring a first output power of a first filter and a second output power of a second filter under each GSM carrier, judging whether power fluctuation of the first output power in preset time is smaller than a preset fluctuation threshold value or not according to the fact that a difference value between the second output power and the first output power is smaller than a first preset threshold value in preset time, carrying out combined judgment, and determining whether the current GSM carrier contains BCCH carriers or not according to a combined judgment result.

Since the carrier of the FCCH channel after GMSK (Gaussian Minimum Shift Keying) modulation is a sine wave, searching the carrier of the FCCH channel is essentially searching a section of sine wave in the locked carrier frequency. And the frequency of the sine wave is 67.708KHz higher than the center frequency of the standard GSM carrier wave. Therefore, this segment of the sine wave can be locked separately by the first filter being constructed. The signal of the whole carrier wave can be obtained by the second filter which is constructed. And the rule of BCCH carrier wave appearing in FCCH carrier wave accords with: and 4 times in the 51 frames are 10 frame intervals, one time is 11 frame intervals, and the BCCH carrier wave appears in the same time slot of the next frame, and after the FCCH carrier wave is detected, the appearance position of the BCCH carrier wave can be determined according to the appearance rule of the BCCH carrier wave in the FCCH carrier wave. That is, it is determined whether the current GSM carrier contains the FCCH and simultaneously contains the BCCH carrier according to the joint decision result.

The specific joint decision may be understood as that only one GSM carrier is searched within a preset time, after the current GSM carrier is searched each time, the output powers of the first filter and the second filter are compared, and if the output powers are both concentrated in a narrow band and meet a first preset threshold, the FCCH carrier can be locked; then determining that the first output power of the first filter meets a preset fluctuation threshold, and determining that the BCCH carrier is contained; therefore, the BCCH carrier wave identification in the GSM carrier wave can be simply and efficiently completed.

In one embodiment applied to the shielding system, at least one set of filters having correlation relationship is constructed in step S100, and the set of filters at least includes the following specific components of the first filter and the second filter.

For the second filter: setting the center frequency and the working bandwidth of the second filter; the center frequency of the second filter is the center frequency of a standard GSM carrier; the working bandwidth of the second filter is 180 KHz-200 KHz. The second filter may be a standard GSM channel filter, i.e. a filter for demodulation in a GSM handset. The standard center frequency is 925 MHz-960 MHz, 1805 MHz-1880 MHz. In one embodiment, the operating bandwidth of the second filter is 200 KHz. The source of 200KHz here may be determined by taking the channel power in the GSM channel. The operating bandwidth of the second filter may be less than 200KHz, but is generally not less than 180KHz, and may be 180KHz, 200 KHz.

For the first filter: setting the center frequency and the working bandwidth of the first filter; the correlation relationship between the first filter and the second filter is that the center frequency of the first filter is 61 KHz-74 KHz higher than that of the second filter, and the numerical range of 61 KHz-74 KHz comprises two endpoints; preferably, the first filter is associated with the second filter such that the center frequency of the first filter is 67.708KHz higher than the center frequency of the second filter. Since the purpose of the first filter is to filter out the FCCH channel, the upper and lower edge frequencies of the first filter must contain the characteristic FCCH channel power, and searching the FCCH channel carrier essentially searches for a sine wave within the locked carrier frequency, which is located 67.708KHz higher than the center of the carrier, so that the center frequency of the first filter needs to contain 67.708 KHz.

The working bandwidth of the first filter is set to be 10 KHz-20 KHz, and the working bandwidth of the first filter can be 10KHz, 15KHz, 20KHz and the like.

In one embodiment, since the filters have relative bandwidths, when the operating bandwidth of the first filter is 20KHz, its relative bandwidth is + -10 KHz. The center frequency of the first filter can be 61KHz, 65KHz, 67.708KHz, 70KHz, 74KHz and the like higher than the center frequency of the standard GSM carrier; the upper and lower edge frequencies of the first filter now comprise 67.708 KHz. Preferably, the center frequency of the first filter is 67.708KHz higher than the center frequency of the standard GSM carrier.

In another embodiment, when the operating bandwidth of the first filter is 10KHz and the relative bandwidth is ± 5KHz, the center frequency of the first filter may be 66KHz to 69KHz higher than the center frequency of the standard GSM carrier, and specifically may be 66KHz, 67.708KHz and 69 KHz. Preferably, the center frequency of the first filter is 67.708KHz higher than the center frequency of the standard GSM carrier.

The calculation of the carrier center frequency also needs to consider engineering routine experience or frequency error, for example, when the operating bandwidth of the first filter is 20KHz, and when the center frequency is 67.708KHz, the upper and lower edge frequencies need to be respectively reserved with 3KHz, and on the premise of rounding, that is, the upper edge frequency is 74 KHz; the lower edge frequency is 61 KHz. Other operating bandwidths may be analogized in turn.

In one embodiment, step S200 includes the steps of: and according to the channel arrangement rule of the GSM carrier, carrying out polling search on the GSM carrier one by one through the first filter and the second filter. The channel arrangement rule refers to all GSM carriers listed according to GSM specifications and GSM carrier frequency bands of different operators; in a control frame period of a GSM carrier, the GSM carrier is polled one by one according to the frequency band from large to small, so that the search of all the GSM carriers is completed quickly.

In an embodiment, as shown in fig. 3, in step S300, the following steps are included, according to that a difference between the second output power and the first output power is smaller than a first preset threshold within a preset time, and whether power fluctuation of the first output power within the preset time is smaller than a preset fluctuation threshold is determined, so as to perform a joint decision, and according to a joint decision result, whether the current GSM carrier contains a BCCH carrier is determined.

S310, judging whether a difference value between the second output power and the first output power is smaller than a first preset threshold value at any time interval within preset time;

s320, if the difference value between the second output power and the first output power is smaller than a first preset threshold value, judging whether the power fluctuation of the first output power in preset time is smaller than a preset fluctuation threshold value;

s330, if the power fluctuation of the first output power in the preset time is smaller than a preset fluctuation threshold, determining that the current GSM carrier contains the BCCH carrier.

S340, after continuously searching for the TDMA frame periods of 11 GSM carriers, if the difference between the second output power and the first output power is not smaller than the first preset threshold and the power fluctuation of the first output power is not smaller than the preset fluctuation threshold, determining that the current GSM carrier does not contain the BCCH carrier.

In one embodiment, the preset time is 142 symbol times. Each symbol time corresponds to 3.69 microseconds (1/270.833KHz) of GSM modulation. As the BCCH carrier of the GSM carrier has an FCCH time slot law (5 FCCH time slots in 51 TDMA frames), i.e. a 4 x 10TDMA frame +1 x 11TDMA frame occurs according to the time dimension of a plurality of FCCHs. Then, within the 142 symbol times, the power difference value output by the first filter and the second filter is smaller than the first preset threshold, and the power is constantly and steadily present within the 142 symbol times (i.e. the power fluctuation is smaller than the first preset threshold), which is considered as a time slot in which the GSM carrier contains the FCCH carrier; and further determining whether the current GSM carrier contains the BCCH carrier or not through the time conformity judgment of the time interval rule of the 5 FCCHs. Of course, if the difference between the second output power and the first output power is not smaller than the first preset threshold, it indicates that the current GSM carrier does not contain the BCCH carrier, and the next round of GSM carrier search is directly performed.

If the difference value between the second output power and the first output power is smaller than the first preset threshold value and the power fluctuation of the first output power output by the first filter is not smaller than the preset fluctuation threshold value after the TDMA frame period of the 11 GSM carriers is continuously searched, that is, the conditions that the difference value between the second output power and the first output power is smaller than the first preset threshold value and the power fluctuation of the first output power output by the first filter is not smaller than the preset fluctuation threshold value are not met at the same time, the current GSM carrier does not contain the BCCH carrier, and the next round of GSM carrier search is directly performed.

In one embodiment, in the FCCH carrier period, only the FCCH signal, i.e. the tone signal with constant power lasting 142 symbol periods and 67.708KHz higher than the center of the carrier, i.e. both the first filter and the second filter get the tone signal (FCCH), is in the entire 200KHz channel, and then the power obtained by the two filters is the same under normal conditions, and the power of the second filter is slightly higher under consideration of external interference. The difference between the second output power and the first output power is therefore positive. In order to ensure the comparison result with the first preset threshold, the absolute value of the difference may be compared with the first preset threshold. In one embodiment, the first predetermined threshold may be 0.4dB to 0.6 dB. Specifically, the first preset threshold may be 0.4dB, 0.5dB, and 0.6 dB; preferably, the first preset threshold may be 0.5 dB. The fluctuation threshold may be 2dB to 4 dB. Specifically, the fluctuation threshold may be prioritized by 2dB, 3dB, and 4dB, and the fluctuation threshold may be 3 dB.

In one embodiment, on the basis of the embodiment of fig. 1, the method further includes: constructing a plurality of sets of related first filters and second filters by using the FPGA; an FPGA (Field-Programmable Gate Array) is a Field Programmable Gate Array, and a plurality of sets of related first filters and second filters which are finished by a hardware description language (Verilog or VHDL) are quickly burned to the FPGA.

In one embodiment, there are multiple associated sets of first and second filters. And searching the GSM carriers with the corresponding quantity through a plurality of sets of first filters and second filters according to the channel arrangement rule of the GSM carriers. For example, with two sets of filters, two GSM carriers can be searched simultaneously. With four sets of filters, four GSM carriers can be searched simultaneously; and a plurality of sets of associated filters are used for searching, so that the searching efficiency can be further improved, and the timeliness is good.

It should be understood that although the various steps in the flow charts of fig. 2-3 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least some of the steps in fig. 2-3 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performance of the sub-steps or stages is not necessarily sequential, but may be performed in turn or alternating with other steps or at least some of the sub-steps or stages of other steps.

In one embodiment, as shown in fig. 4, there is provided an apparatus for identifying BCCH carriers in GSM carriers based on filters, the apparatus comprising a building block 100, a searching block 200 and a decision block 300: the construction module 100 is configured to construct at least one set of filters having an association relationship, where the set of filters includes at least a first filter and a second filter; the searching module 200 is configured to search all GSM carriers through the first filter and the second filter; the decision module 300 is configured to obtain a first output power of a first filter and a second output power of a second filter under each GSM carrier, determine whether power fluctuation of the first output power within a preset time is smaller than a preset fluctuation threshold according to that a difference between the second output power and the first output power is smaller than a first preset threshold within a preset time, perform joint decision, and determine whether the current GSM carrier contains a BCCH carrier according to a joint decision result.

The device provided by the invention can simply and efficiently finish the identification of BCCH carriers in GSM carriers and has good timeliness.

In one embodiment, module 100 is constructed to further set the center frequency and the operating bandwidth of the first filter; setting the center frequency and the working bandwidth of the second filter; the center frequency of the first filter is higher than the center frequency of the second filter.

In one embodiment, the module 100 is further configured to set the center frequency of the first filter to be 61KHz to 74KHz higher than the center frequency of the standard GSM carrier; the working bandwidth of the first filter is set to be 10 KHz-20 KHz.

In one embodiment, the module 100 is further configured to set the center frequency of the second filter to be the center frequency of the standard GSM carrier; the working bandwidth of the second filter is set to be 180 KHz-200 KHz.

In one embodiment, the building block 100, further configured to set a center frequency and an operating bandwidth of the first filter, includes: setting the central frequency of the first filter to be 61 KHz-74 KHz higher than that of the second filter, wherein the numerical range of 61 KHz-74 KHz comprises two endpoints; the working bandwidth of the first filter is set to be 10 KHz-20 KHz.

In one embodiment, the searching module 200 is further configured to perform a polling search on GSM carriers one by one through the first filter and the second filter according to the channel arrangement rule of the GSM carriers.

In an embodiment, the determining module 300 is further configured to determine whether a difference between the second output power and the first output power is smaller than a first preset threshold at any time period within a preset time;

In an embodiment, the decision module 300 is further configured to, after continuously searching for TDMA frame periods of 11 GSM carriers, determine that the current GSM carrier does not contain a BCCH carrier if a difference between the second output power and the first output power is not smaller than a first preset threshold and power fluctuation of the first output power is not smaller than a preset fluctuation threshold.

In one embodiment, on the basis of the embodiment in fig. 4, the system further includes an FPGA building module: and the FPGA constructing module is used for constructing a plurality of sets of related first filters and second filters by utilizing the FPGA. After a number of associated sets of first and second filters are constructed using the FPGA, the search is then adjusted accordingly. The GSM carrier is searched through a plurality of sets of first filters and second filters according to the channel arrangement rule of the GSM carrier.

For a specific definition of the identification means with BCCH carrier in the filter-based GSM carrier, reference may be made to the above definition of the identification method with BCCH carrier in the filter-based GSM carrier, which is not described herein again. The various modules in the filter-based identification means of the BCCH carrier in the GSM carrier described above can be implemented wholly or partly by software, hardware and combinations thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.

In one embodiment, a computer device, which may be a server, is provided that includes a processor, a memory, a network interface, and a database connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The database of the computer device is used for storing identification data of BCCH carriers in the filter-based GSM carriers. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program is executed by a processor to implement a filter-based method of identifying BCCH carriers in GSM carriers.

Those skilled in the art will appreciate that the architecture shown in fig. 5 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.

In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having a computer program stored therein, the processor implementing the following steps when executing the computer program:

constructing at least one set of filters with an association relationship, wherein the set of filters at least comprises a first filter and a second filter; searching all GSM carriers through a first filter and a second filter; the method comprises the steps of obtaining first output power of a first filter and second output power of a second filter under each GSM carrier, judging whether power fluctuation of the first output power in preset time is smaller than a preset fluctuation threshold value or not according to the fact that the difference value of the second output power and the first output power is smaller than a first preset threshold value in preset time, carrying out joint judgment, and determining whether the current GSM carrier contains BCCH carriers or not according to a joint judgment result.

In one embodiment, a computer-readable storage medium is provided, having a computer program stored thereon, which when executed by a processor, performs the steps of:

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A method for identifying BCCH carriers in GSM carriers based on filters, the method comprising:

searching all GSM carriers through the first filter and the second filter;

2. The method of claim 1, wherein constructing at least one filter set having an association relationship, the filter set including at least a first filter and a second filter, comprises:

setting the center frequency and the working bandwidth of the first filter;

setting the center frequency and the working bandwidth of the second filter;

3. The method of claim 2, wherein setting the center frequency and the operating bandwidth of the second filter comprises:

the working bandwidth of the second filter is set to be 180 KHz-200 KHz.

4. The method of claim 3, wherein setting the center frequency and the operating bandwidth of the first filter comprises:

the working bandwidth of the first filter is set to be 10 KHz-20 KHz.

5. The method of claim 4, wherein the center frequency of the first filter is 67.708KHz higher than the center frequency of the second filter.

6. The method of any one of claims 1 to 5, wherein the searching for all GSM carriers by the first filter and the second filter comprises:

7. The method of claim 6, wherein determining whether the current GSM carrier contains a BCCH carrier according to a joint decision result by determining whether a power fluctuation of the first output power within a preset time is smaller than a preset fluctuation threshold within a preset time according to a difference between the second output power and the first output power being smaller than a first preset threshold within a preset time comprises:

8. The method of claim 7, further comprising:

9. The method of claim 6, further comprising:

10. A recognition device of BCCH carrier wave in GSM carrier wave based on filter, characterized in that, the device includes a construction module, a search module and a decision module:

11. A computer device comprising a memory and a processor, the memory storing a computer program, wherein the processor implements the steps of the method of any one of claims 1 to 9 when executing the computer program.

12. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 9.