CN102348202B - Communication apparatus and control method thereof - Google Patents

Abstract

The invention discloses a communication device comprising a receiving unit and a decision unit. The receiving unit is used for receiving the first cluster in a paging message provided by the communication base station. The determining unit compares a signal-to-noise ratio with a threshold value to generate a comparison result, and determines a judging mechanism according to the comparison result to judge whether the paging message is a virtual paging message. The signal-to-noise ratio is related to a channel traveled by the first cluster.

Description

Communication device and control method thereof

technical field

The present invention relates to communication systems, and more particularly to an apparatus and method for detecting virtual paging messages.

Background technique

In currently used wireless communication systems, such as the GSM communication system, a base station sends an incoming call notification to mobile communication devices within its coverage area through a paging message. In the case of no incoming call, the base station will still periodically send a dummy paging message (dummy paging message) that does not contain substantial information (incoming call notification), so as to maintain the synchronization state between the base station and the mobile communication device. In fact, most of the time the base stations send virtual paging messages.

Please refer to FIG. 1 . FIG. 1 is an example of a partial functional block diagram corresponding to the transmitting end/receiving end of the communication system. The transmitting end 10 can be regarded as the transmitting device in the base station, and the receiving end 20 can be regarded as the receiving device in the mobile communication device. In the GSM system, the original message codes of both the real paging message and the virtual paging message contain 228-bit data, of which 40 bits are redundant codes (redundancy code) for the receiving end 20 to detect errors. After the 1/2 rate convolution coding process provided by the encoder 12, the original message code will be transformed into 456-bit coded data. The interleaver 14 is responsible for breaking up the encoded data into four bursts each containing 114-bit data. Then, the four clusters are processed by the mapping unit 16 and the modulation unit 18 , and then sent out sequentially in the form of radio frequency signals.

The RF receiver 21 of the receiving end 20 will sequentially receive the RF signals corresponding to the above four clusters. After demodulation by the demodulation unit 22, elimination of the channel impulse response program by the channel equalizer (channel equalizer) 23, rearrangement by the deinterleaver (deinterleaver) 24, and decoding by the decoder 25, these radio frequency signals will be converted into 228-bit recovery message code. Then, the subsequent circuit will be responsible for judging whether the restored message code represents a real paging message or a virtual paging message, and perform corresponding processing.

Theoretically, the receiving end 20 judges the type of the paging message after completely receiving the four clusters and reconstructing them into restored message codes. However, if the paging message is a virtual paging message, none of the four clusters has substantive information such as call information. For a mobile communication device that emphasizes long-lasting standby capability, it is quite unreasonable waste to consume power for receiving a large number of invalid messages.

Currently, there is a technology for judging whether a paging message is valid based only on the first cluster among the four clusters. If the judgment result generated by the first cluster shows that the paging message it belongs to is a virtual paging message, the receiver in the communication device stops receiving signals corresponding to the subsequent three clusters, thereby saving the consumption of the communication device when receiving signals electricity. However, not all situations are suitable for the above-mentioned solution. For example, in the case of severe noise interference, only using the first cluster to determine whether the paging message is valid may cause misjudgment, causing the communication device to miss the actual paging message with important information.

Contents of the invention

In order to solve the above problems, the communication device and its control method provided by the present invention take into consideration the signal-to-noise ratio (SNR) of the environment where the communication device is located. If the signal-to-noise ratio shows that the current communication environment is ideal, the communication device can adopt a judging mechanism of judging whether the paging message is virtual based only on the first cluster, thereby achieving the effect of saving power. Relatively, if the signal-to-noise ratio shows that the current communication environment is poor, the communication device can adopt a judging mechanism for judging whether the paging message is virtual based on multiple clusters, thereby reducing the probability of misjudgment.

In addition, the communication device and the control method provided by the present invention can also take into consideration the mobile identification number (MIN) of the communication device itself. If a mobile ID is similar to the content of the virtual paging message, the mobile ID can be classified into a blacklist group. In other words, the blacklist group includes mobile identification codes that are more sensitive to noise, and once interfered by noise, they may be misjudged as part of the virtual paging message. If the mobile identification code of a certain communication device belongs to the blacklist group, the communication device can be designed to judge whether the paging message is virtual based on multiple clusters when the SNR is low, so as to improve the accuracy of the judgment .

A specific embodiment according to the present invention is a communication device including a receiving unit and a determining unit. The receiving unit is used for receiving the first cluster in a paging message provided by the communication base station. The determining unit is used for comparing a signal-to-noise ratio with a threshold value to generate a comparison result, and determine a judging mechanism according to the comparison result to judge whether the paging message is a virtual paging message. The signal-to-noise ratio is related to the channel traveled by the first cluster.

Another specific embodiment according to the present invention is a control method applied to a communication device. In the method, the step of receiving a first cluster in a paging message is firstly performed. Then, the method compares a signal-to-noise ratio with a first threshold value to generate a comparison result, and determines a judging mechanism according to the comparison result to judge whether the paging message is a virtual paging message.

The concept of the present invention can be widely applied to various communication systems with virtual paging messages. The advantages and spirit of the present invention can be understood through the following detailed description of the invention and the accompanying drawings.

Description of drawings

This case can be understood through the following diagrams and explanations:

FIG. 1 is a functional block diagram corresponding to the transmitting end/receiving end of the communication system.

FIG. 2 is a functional block diagram of a communication device according to a first embodiment of the present invention.

3A-3D are flow charts of the determination procedure of the determination unit according to the present invention.

FIG. 4 shows a partial format of the actual paging message in the system.

FIG. 5 is a circuit block diagram of an embodiment of a communication device according to the present invention.

FIG. 6 shows the data content of the virtual paging message in the system.

FIG. 7 is a flowchart of a method for controlling a communication device according to the present invention.

[Description of main component symbols]

The components contained in the attached drawings of this case are listed as follows:

10 Transmitter 12 Encoder

14 interleavers 16 mapping units

18 modulation unit 20 receiving end

21 RF receiver 22, 32, 62 demodulation units

23, 33, 63 channel equalizer 24, 34, 64 deinterleaver

25, 35, 65 decoder 30, 60 communication device

31, 61 receiving unit 36, 68 decision unit

66 replacement units 67 error detection units

69 control unit S42～S47 process steps S801～S811 process steps

Detailed ways

Please refer to FIG. 2 , which is a functional block diagram of a communication device according to a first embodiment of the present invention. The communication device is suitable for a communication system including at least one base station. The communication device 30 in this embodiment includes a receiving unit 31 , a demodulating unit 32 , a channel equalizer 33 , a deinterleaver 34 , a decoder 35 and a determining unit 36 . The determination unit 36 can be integrated in the communication device 30 or can be independent from the communication device 30 . In practical applications, the communication device 30 may represent a communication chip built in a mobile phone or the mobile phone itself, and the receiving unit 31 may include circuits such as radio frequency modules and analog-to-digital converters.

At different times and places, the signal-to-noise ratio of the environment where the communication device 30 is located will vary. In other words, the signal-to-noise ratio is related to the condition of the channel through which the paging message travels. The communication device 30 can estimate the signal-to-noise ratio according to the wireless signal received by the receiving unit 31 as a reference value for adjusting internal settings. In practice, the communication device 30 may estimate the SNR periodically, or estimate the SNR every time a wireless signal is received. A higher signal-to-noise ratio means that the signal is less damaged by environmental noise, which means that the accuracy of the signal received by the receiving unit 31 is higher.

As mentioned above, the base station will send the incoming call notification to the mobile communication devices in its coverage area through the paging message, and most of the time the base station sends the virtual paging message. In this embodiment, when the communication device 30 needs to judge whether a paging message is virtual, there are two possible judging mechanisms, one is to judge only according to one cluster in the paging message, and the other is to judge according to at least two clusters in the paging message. cluster for judgment. The decision unit 36 compares the current signal-to-noise ratio with a first threshold value to generate a comparison result, and determines a judging mechanism according to the comparison result to judge whether the paging message is virtual. In this embodiment, if the signal-to-noise ratio is higher than the first threshold, the determining unit 36 suggests to the communication device 30 to determine whether the paging message is virtual according to the first cluster in the paging message. Once the judgment result generated according to the first cluster shows that the paging message is virtual, the receiving unit 31 can stop receiving the subsequent three clusters of the paging message, thereby saving power.

In contrast, if the signal-to-noise ratio is lower than the first threshold, the determining unit 36 enables the communication device 30 to determine whether the paging message is virtual according to at least two clusters in the paging message. More specifically, when the signal-to-noise ratio is lower than the first threshold, the communication device 30 will receive at least two clusters in the paging message, and judge whether the paging message is virtual according to the clusters. In this way, in the case of high noise interference, the communication device 30 may reduce the probability of misjudging the real paging message as a virtual paging message or misjudging the virtual paging message as a real paging message.

It can be seen that the communication device 30 in this embodiment does not use the first cluster as the basis for judging whether the paging message is a virtual paging message in all cases, nor does it use multiple clusters as the basis for judging in all cases . By taking the signal-to-noise ratio into consideration, the communication device 30 can find a balance between power saving and false positive rate reduction. In practice, the first threshold can be determined according to simulation or experiment, and can be designed to be adjustable. It should be noted that the main function of the determination unit 36 is to determine which determination mechanism should be adopted for the communication device 30 . In order to perform the above-mentioned procedure of judging whether the paging message is virtual according to one or more clusters, the communication device 30 may include other circuits not shown in FIG. 2 .

FIG. 3A is a flow chart of the operation procedure of the determination unit 36 . Step S42 is to compare whether the signal-to-noise ratio is higher than a first threshold. If the comparison result of step S42 is yes, as shown in step S43, the judging mechanism adopted by the communication device 30 is to judge whether the paging message is virtual according to the first cluster in the paging message. If the comparison result of step S42 is negative, as shown in step S44, the judging mechanism adopted by the communication device 30 is to judge whether the paging message is virtual according to at least two clusters in the paging message.

According to the present invention, in addition to the signal-to-noise ratio, the determining unit 36 may also take into consideration the mobile identification code of the communication device 30 . The mobile identification code is usually stored in the memory of the communication device 30 and may change with different network areas where the communication device 30 is located. Different communication devices in the same network area have different mobile identification codes for identifying the communication devices. When the communication base station sends a real paging message to inform the communication device 30 of incoming call information or short messages, the real paging message will include the mobile identification code of the communication device 30 . In practice, a real paging message may include multiple mobile identification codes of different communication devices at the same time.

Taking the GSM system as an example, the number of bits contained in the virtual paging message and the real paging message are the same, and the main difference between the two messages is whether they contain real information, such as mobile identification codes of one or more communication devices. In the virtual paging message sent by the base station, the fields that do not contain substantive information will be filled with the same binary filling content, such as 00101011 (2B in hexadecimal notation). This binary content is defined in the GSM standard. Through actions such as restoration, after receiving a paging message, the communication device 30 can pass some specific fields, such as the paging request type field and the paging mode field, or other fields Whether it is filled with filling content such as 00101011 to determine whether the paging message is a virtual paging message.

Please refer to FIG. 4. FIG. 4 shows a partial format of the actual paging message in the GSM system. The value of "identification code content length" in the first byte is 3; the second byte and the third byte are used to represent the mobile identification code; starting from the fourth byte, except for those carrying substantial information field, the remaining fields may be filled with 00101011. The paging message (184 bits with different meanings) sent by the base station is interleaved into four 114-bit cluster codes through convolution, interleaving and other coding procedures. It can be seen from this that the less mobile identification code information the real paging message contains, the more similar the overall content of the real paging message will be to the virtual paging message. In addition, the most similar situation between the actual paging message and the virtual paging message occurs when the actual paging message only has a mobile identification code, and the mobile identification code stored in the third byte and the filling code 00101011 have only a 1-bit difference ( For example, when the content of the third byte is 00101010 or 01101011). In such a situation, the paging message is divided into four clusters and sent through the above encoding process, and after being affected by channel noise during transmission, the only 1-bit difference is likely to disappear or cannot be detected. The wrong mechanism is judged. Therefore, the communication device 30 is more likely to misjudge the real paging message as a virtual paging message.

For a communication device whose third byte corresponding to the mobile identification code is quite different from 00101011, even if the actual paging message in the worst case above is misjudged as a virtual paging message, the missed call is to call other communication devices , so it has no effect. However, for a communication device with only 1 bit difference between the 3rd byte corresponding to the mobile identification code and 00101011, misjudgment will lead to missing important messages. In view of this, the two types of communication devices with different mobile identification codes can be designed to adopt different judgment criteria.

According to a specific embodiment of the present invention, a blacklist group can be pre-established and stored in the communication device 30 . The blacklist group includes mobile IDs that are more sensitive to noise, that is, mobile IDs that may be misjudged as part of a virtual paging message once interfered by noise. If the mobile identification code of the communication device 30 belongs to the blacklist group, the communication device 30 can use the method of judging whether the paging message is virtual based on multiple clusters when the signal-to-noise ratio is slightly low, so as to reduce misjudgment probability.

The blacklist group is established according to the possible content of the virtual paging message, and can be determined through simulation or experiment. As far as the GSM message shown in Figure 4 is concerned, there are 17 possibilities for the "identification code byte 1" consisting of four bits, and the field content of the "identification code type" in the second byte is 001 . There are eight possibilities for the 3rd byte and 00101011 to differ by only 1 bit. It can be deduced from the above description that there are 544 mobile identification codes combined from these possibilities. For example, in one embodiment, the designer can simulate various environmental conditions, and then select 30 mobile identification codes corresponding to a higher false positive rate from the 544 mobile identification codes to form the blacklist group. The blacklist group can be pre-stored in the memory of the communication device 30 . In other embodiments, the blacklist group may include all possible 544 mobile IDs.

Please refer to FIG. 3(B). FIG. 3(B) shows a flow chart of another judgment procedure that can be used by the decision unit 36 to illustrate an embodiment that considers the signal-to-noise ratio and the mobile identification code at the same time. Similarly, if the determination result of step S42 is yes, as shown in step S43, the determination mechanism adopted by the communication device 30 is to determine whether the paging message is virtual according to the first cluster in the paging message. If the determination result of step S42 is negative, the decision unit 36 in this embodiment reads the current mobile identification code of the communication device 30 from the memory, and as shown in step S45, determines whether the mobile identification code belongs to the blacklist group. If the judgment result of step S45 is negative, it means that the communication device 30 can adopt a more relaxed and power-saving judgment mechanism, that is, it can judge whether the paging message is virtual or not according to the first cluster as shown in step S43. In contrast, if the judgment result of step S45 is yes, it means that the communication device 30 can adopt a stricter and more accurate judgment mechanism, that is, as shown in step S44, judge whether the paging message is virtual or not according to at least two clusters.

In practical applications, the decision unit 36 may also use two thresholds with different heights as judgment criteria. Please refer to FIG. 3(C). FIG. 3(C) shows a flow chart of another judgment procedure that can be used by the decision unit 36 to illustrate an embodiment that considers two signal-to-noise ratio thresholds. The second threshold value is lower than the first threshold value, and in practice may be the first threshold value minus a specific tolerance, for example, the second threshold value may be 80% of the first threshold value. If the judgment result of step S42 is negative, the decision unit 36 in this embodiment will execute step S46 to judge whether the signal-to-noise ratio in the environment where the communication device 30 is located is higher than the second threshold. If the judgment result of step S46 is negative, it means that the current signal-to-noise ratio is too low, and the decision unit 36 will make the communication device 30 use the mechanism of judging whether the paging message is virtual based on at least two clusters for all paging messages. In contrast, if the judgment result of step S46 is yes, indicating that the current signal-to-noise ratio is between the second threshold value and the first threshold value, the determination unit 36 will then determine the movement of the communication device 30 as shown in step S45. Whether the identification code belongs to the blacklist group, and which judging mechanism the communication device 30 will adopt is determined according to the judging result of step S45.

The flowchart shown in FIG. 3D further includes a step S47 of judging whether the mobile identification code meets a preset condition. The preset condition may be: the difference between a specific section of the mobile identification code and a feature code of the virtual paging message is less than a predetermined value. For example, the preset condition may be: the length of the mobile identification code is 3 bits, and there is only 1 bit difference between the 3rd byte in the mobile identification code as shown in FIG. 4 and 00101011. If the determination result of step S47 is yes, it means that the mobile identification code is quite similar to part of the virtual paging message. In such a case, the determining unit 36 will continue to execute step S45 to determine the judging mechanism that the communication device 30 should adopt according to whether the mobile identification code of the communication device 30 belongs to the blacklist group. In this embodiment, if the judgment results of step S45 and step S47 are both yes, the communication device 30 will adopt a stricter and more accurate judgment mechanism to judge whether the paging message is virtual or not according to at least two clusters.

In another embodiment, the determination unit may adopt another determination procedure, which only considers the mobile identification code of the communication device. Similar to the judging step in the previous embodiment, as long as the mobile ID of the communication device belongs to the blacklist group, the determining unit in this embodiment makes the communication device judge whether the paging message is virtual or not according to at least two clusters. In contrast, if the mobile identification code of the communication device does not belong to the blacklist group, the determining unit instructs the communication device to determine whether the paging message is virtual according to the first cluster.

FIG. 5 is a circuit block diagram of a communication device for illustrating how the communication device according to the present invention can determine whether the paging message is virtual according to the first cluster. This communication device 60 includes a receiving unit 61, a demodulation unit 62, a channel equalizer 63, a data processing unit composed of an inverse interleaver 64 and a decoder 65, a replacement unit 66, an error detection unit 67, a decision unit 68, and a control unit 69. The operation mode of the determining unit 68 may be the same as that of any one of the determining unit 36 in the previous embodiments, so it will not be repeated here.

Firstly, the situation when the determining unit 68 instructs the communication device 60 to determine whether the paging message is virtual or not according to the first cluster is described. After the first cluster of a paging message is received by the receiving unit 61 , it will first be processed by the demodulation unit 62 and the channel equalizer 63 . Assume that the output signal of the channel equalizer 63 corresponding to the first cluster is B0. In this embodiment, B0 and a plurality of preset bits pre-stored in the memory of the communication device 60 are combined into a composite message in the deinterleaver 64 , and the composite message is deinterleaved by the deinterleaver 64 .

The predetermined bits correspond to at least one subsequent cluster in the virtual paging message. Taking the GSM system as an example, assuming that the four clusters in a virtual paging message pass through the channel equalizer 63 in sequence, the output signal is [B1 B2B3 B4], where [B2 B3 B4] can be used as the above-mentioned preset bit , used to form a combined message with B0 [B0 B2B3 B4]. If B0 does correspond to a virtual paging message, the combined message [B0 B2 B3 B4] should be similar to [B1 B2B3 B4], and the results of [B0 B2 B3 B4] and [B1 B2 B3 B4] after the deinterleaving process should also be similar .

FIG. 6 shows the data content of the virtual paging message in the GSM system. As shown in Figure 6, in the column corresponding to the 3rd byte indicator, the value of M may be 0000, 0001, 0010, 0011, and in the column corresponding to the 5th byte indicator, the value of F Then it could be 0000 or 1111. Therefore, there are eight possible data contents for a virtual paging message in the GSM system. After observation, it can be found that many bits of the eight possible data contents are the same. Taking the second cluster as an example, 89 bits of its 114-bit data remain unchanged in the above eight situations. B2 in the above preset bits [B2 B3 B4] can be designed to contain the 89-bit fixed data, and fill the positions of the other 25 bits with 0.

Similarly, the 87-bit and 90-bit data in the third cluster and fourth cluster of the GSM virtual paging message remain unchanged in the above eight situations. Therefore, B3 in the preset bit [B2 B3 B4] can be designed to contain the 87-bit fixed data, and fill the position of the other 27 bits with 0; B4 can be designed to contain the 90-bit The fixed data, and fill the other 24 bits with 0.

Next, the decoder 65 is responsible for decoding the 456-bit data after deinterleaving to generate a decoded message including 228-bit data. As mentioned earlier, the decoded message in the GSM system should contain a 40-bit redundancy code for the communication device 60 to detect errors. In order to ensure that the error detection result will not be wrong due to the above-mentioned method of filling some bits with 0, the replacement unit 66 replaces the parity bit (parity bit) in the decoded message with 40 known first test parity bits ) to generate a first post-replacement message. The 40 first test parity bits correspond to the case where the value of F is 0000. More specifically, the group of first test parity bits corresponds to the redundant code signal that the virtual paging message with F equal to 0000 should theoretically obtain at the output end of the decoder 65 . In addition, the replacement unit 66 can also replace the part of the parity bits in the decoded message with 40 second test parity bits for the case where the value of F is 1111, so as to generate a second post-replacement message.

The error detection unit 67 first performs an error detection, such as cyclic redundancy check, on the first replaced message. If the first cluster received by the receiving unit 61 corresponds to the virtual paging message with F equal to 0000, the corresponding error rate obtained by the error detection unit 67 will be lower than a preset threshold. According to the first detection result, the error detection unit 67 may determine that the paging message to which the first cluster belongs is a virtual paging message. If the first detection result shows that the error rate is higher than the preset threshold, the error detection unit 67 will continue to perform error detection on the second replaced message. If the first cluster received by the receiving unit 61 corresponds to the virtual paging message with F equal to 1111, the error rate corresponding to the second replaced message will be lower than the preset threshold.

If the error rates corresponding to the first replaced message and the second replaced message are both higher than the preset threshold, the error detection unit 67 may determine that the paging message to which the first cluster belongs is not a virtual paging message. In this case, the control unit 69 may request the receiving unit 61 to continue receiving subsequent bursts of the paging message. When processing the next three clusters, the control unit 69 can control the deinterleaver 64 to stop its combination process, and control the replacement unit 66 to stop its replacement process.

On the other hand, when the decision unit 68 makes the communication device 60 judge whether the paging message is virtual according to multiple clusters through the control unit 69, the control unit 69 can also control the deinterleaver 64 to stop its combination process, and control the replacement unit 66 stops its replacement procedure.

In practice, since the number of bits of the preset bit [B2 B3 B4] is higher than the number of bits of B0 corresponding to the first cluster, in order to avoid the error detection of the error detection unit 67 dominated by the preset bit [B2 B3 B4] As a result, the preset bit [B2B3 B4] can be generated by multiplying the original preset bits by the equalization gain. For example, assuming that B0 after passing through the channel equalizer 63 is a quantized value with upper and lower limits between ±128, the original preset bits expressed in binary can be multiplied by an equalization within the range of ±10 Gain, so that the quantization value of each bit in the preset bit [B2 B3 B4] is distributed between ±10.

Please refer to FIG. 7 . FIG. 7 is a flowchart of a control method of a communication device according to the present invention, which is used to illustrate how the communication device can determine whether the paging message is virtual according to the first cluster. Step S801 is to receive a first cluster in a paging message. Step S802 is to compose a combined message with the first cluster and a plurality of preset bits. Next, in step S803, the combined message is deinterleaved and decoded. Step S804 replaces the plurality of check bits in the decoded message with a plurality of first test check bits to generate a first replaced message. Step S805 is to perform error detection on the first replaced message.

Step S806 determines whether the error rate corresponding to the first replaced message is lower than a threshold. If the determination result of step S806 is yes, the method determines in step S807 that the paging message to which the first cluster belongs is a virtual paging message. In contrast, if the determination result of step S806 is negative, step S808 will be executed to replace the plurality of check bits with a plurality of second test check bits to generate a second post-replacement message. Next, steps S809 and S810 are respectively performing error detection on the second replaced message, and determining whether the error rate corresponding to the second replaced message is lower than a threshold value. If the determination result of step S810 is yes, the method will also execute step S807 to determine that the paging message belonging to the first cluster is a virtual paging message. If the determination result of step S810 is negative, the method determines in step S811 that the paging message to which the first cluster belongs is not a virtual paging message.

As mentioned above, the communication device and its control method provided by the present invention take into consideration the signal-to-noise ratio of the environment where the communication device is located and/or the mobile identification code of the communication device itself, so as to decide whether to use a more power-saving method. The judging mechanism or the judging mechanism with higher accuracy, so as to take into account and balance the needs of saving power and reducing the misjudgment rate. The concept of the present invention can be widely applied to various communication systems with virtual paging messages.

Through the above detailed description of the preferred embodiments, it is hoped that the features and spirit of the present invention can be described more clearly, rather than limiting the scope of the present invention by the preferred embodiments disclosed above. On the contrary, the intention is to cover various changes and equivalent arrangements within the scope of the claimed patent scope of the present invention.

Claims (24)

1. A communication device, suitable for a communication system with a communication base station, the communication device comprising: a receiving unit for receiving a first cluster in a paging message provided by the communication base station; and A determining unit, comparing a signal-to-noise ratio with a first threshold value to generate a comparison result, and determining a judgment mechanism based on the comparison result to judge whether the paging message is a virtual paging message, wherein the signal the noise-to-noise ratio is related to a channel traveled by the first cluster, If the signal-to-noise ratio is lower than the first threshold value, the determining unit reads a mobile identification code of the communication device, and further determines the judgment mechanism according to the mobile identification code. 2. The communication device according to claim 1, wherein if the signal-to-noise ratio is higher than the first threshold value, the judgment mechanism is to judge whether the paging message is the virtual paging message according to the first cluster. 3. The communication device according to claim 1, wherein the determining unit judges whether the mobile identification code belongs to a blacklist group, if the mobile identification code does not belong to the blacklist group, the judgment mechanism is based on The first cluster determines whether the paging message is the virtual paging message. 4. The communication device according to claim 3, wherein if the mobile identification code belongs to the blacklist group, the judging mechanism is to judge whether the paging message is the virtual group according to at least two clusters in the paging message. paging message. 5. The communication device according to claim 1, wherein if the signal-to-noise ratio is lower than the first threshold value, the determining unit further determines whether the signal-to-noise ratio is higher than a second threshold value, if The signal-to-noise ratio is lower than the second threshold, and the judging mechanism is to judge whether the paging message is the virtual paging message according to at least two clusters in the paging message, wherein the second threshold is lower than the first threshold value. 6. The communication device according to claim 5, wherein if the signal-to-noise ratio is lower than the first threshold and higher than the second threshold, the determination unit further determines whether the mobile identification code belongs to a Blacklist group, if the mobile identification code does not belong to the blacklist group, the judging mechanism is to judge whether the paging message is the virtual paging message according to a first cluster in the paging message. 7. The communication device according to claim 6, wherein if the mobile identification code belongs to the blacklist group, the judging mechanism is to judge whether the paging message is the virtual group according to at least two clusters in the paging message. paging message. 8. The communication device according to claim 5, wherein if the signal-to-noise ratio is lower than the first threshold and higher than the second threshold, the determination unit further determines whether the mobile identification code meets a A preset condition. If the mobile identification code does not meet the preset condition, the judging mechanism is to judge whether the paging message is the virtual paging message according to the first cluster. 9. The communication device according to claim 8, wherein the default condition is that the difference between a specific section of the mobile identification code and a feature code of the virtual paging message is less than a predetermined value. 10. The communication device according to claim 8, wherein if the mobile identification code meets the preset condition, the determining unit further determines whether the mobile identification code belongs to a blacklist group, and if the mobile identification code does not Belonging to the blacklist group, the judgment mechanism is to judge whether the paging message is the virtual paging message according to the first cluster. 11. The communication device according to claim 10, wherein if the mobile identification code meets the preset condition and the mobile identification code belongs to the blacklist group, the judging mechanism is based on at least two of the paging messages. A cluster judges whether the paging message is the virtual paging message. 12. A communication device, suitable for a communication system having a communication base station, the communication device comprising: a receiving unit for receiving a first cluster in a paging message provided by the communication base station; and A determining unit, comparing a signal-to-noise ratio with a first threshold value to generate a comparison result, and determining a judgment mechanism based on the comparison result to judge whether the paging message is a virtual paging message, wherein the signal the noise-to-noise ratio is related to a channel traveled by the first cluster, If the signal-to-noise ratio is lower than the first threshold, the judging mechanism is to judge whether the paging message is the virtual paging message according to at least two clusters in the paging message. 13. A control method applied to a communication device, comprising the following steps: (a) receiving a first cluster in a paging message provided by a communication base station; and (b) Comparing a signal-to-noise ratio with a first threshold value to generate a comparison result, and determining a judging mechanism based on the comparison result to judge whether the paging message is a virtual paging message, wherein the signal-noise ratio A signal ratio is associated with a channel traveled by the first cluster, Step (b) includes: If the signal-to-noise ratio is lower than the first threshold value, read a mobile identification code of the communication device, and further determine the judging mechanism according to the mobile identification code. 14. The control method according to claim 13, wherein if the signal-to-noise ratio is higher than the first threshold, the judgment mechanism is to judge whether the paging message is the virtual paging message according to the first cluster. 15. The control method according to claim 13, wherein step (b) comprises: judging whether the mobile identification code belongs to a blacklist group; Wherein if the mobile identification code does not belong to the blacklist group, the judgment mechanism is to judge whether the paging message is the virtual paging message according to the first cluster. 16. The control method according to claim 15, wherein if the mobile identification code belongs to the blacklist group, the judging mechanism is to judge whether the paging message is the virtual group according to at least two clusters in the paging message. paging message. 17. The control method according to claim 13, wherein step (b) comprises: If the signal-to-noise ratio is lower than the first threshold, determine whether the signal-to-noise ratio is higher than a second threshold; Wherein the second threshold value is lower than the first threshold value, if the signal-to-noise ratio is lower than the second threshold value, the judging mechanism is to judge whether the paging message is the virtual paging message. 18. The control method according to claim 17, wherein step (b) comprises: If the signal-to-noise ratio is lower than the first threshold and higher than the second threshold, determine whether the mobile identification code belongs to a blacklist group; Wherein if the mobile identification code does not belong to the blacklist group, the judgment mechanism is to judge whether the paging message is the virtual paging message according to the first cluster. 19. The control method according to claim 18, wherein if the mobile identification code belongs to the blacklist group, the judging mechanism is to judge whether the paging message is the virtual group according to at least two clusters in the paging message paging message. 20. The control method according to claim 17, wherein step (b) comprises: If the signal-to-noise ratio is lower than the first threshold and higher than the second threshold, determine whether the mobile identification code meets a preset condition; Wherein if the mobile identification code does not meet the preset condition, the judgment mechanism is to judge whether the paging message is the virtual paging message according to the first cluster. 21. The control method according to claim 20, wherein the default condition is that the difference between a specific segment of the mobile identification code and a feature code of the virtual paging message is less than a predetermined value. 22. The control method according to claim 20, wherein step (b) comprises: If the mobile identification code meets the preset condition, determine whether the mobile identification code belongs to a blacklist group; Wherein if the mobile identification code does not belong to the blacklist group, the judgment mechanism is to judge whether the paging message is the virtual paging message according to the first cluster. 23. The control method according to claim 22, wherein if the mobile identification code meets the preset condition and the mobile identification code belongs to the blacklist group, the judging mechanism is based on at least two of the paging messages. A cluster judges whether the paging message is the virtual paging message. 24. A control method applied to a communication device, comprising the following steps: (a) receiving a first cluster in a paging message provided by a communication base station; and (b) Comparing a signal-to-noise ratio with a first threshold value to generate a comparison result, and determining a judging mechanism based on the comparison result to judge whether the paging message is a virtual paging message, wherein the signal-noise ratio A signal ratio is associated with a channel traveled by the first cluster, If the signal-to-noise ratio is lower than the first threshold, the judging mechanism is to judge whether the paging message is the virtual paging message according to at least two clusters in the paging message.