Abstract:
The present invention relates to a wireless communication system and a method thereof. The wireless communication system comprises a signal encoding module for encoding a preset high-frequency audio signal frequency according to a preset encoding rule, and creating an encoding library for storing the code; a signal sampling module for sampling a high-frequency audio signal produced by a high-frequency audio signal generating device; a signal transformation module for performing Fourier transformation on the sampled audio signal firstly to transform the audio signal into frequencies, acquiring a main frequency from the transformed frequencies, and storing the acquired main frequency; a signal decoding module for decoding the main frequency into a preset code according to the code in the library; and an output module for outputting the decoded code. The wireless communication system and the method of the present invention do not need hardware supports, thereby reducing the cost.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a communication system and a method thereof, in particular to a system and a method for communication via an audio signal. 
     BACKGROUND 
     On current market, there are many non-contact communication devices in demand of hardware supports, for example, RFID technology which needs a special identification card in use. Taking its application to a membership card for example, a user who is the member of many shops needs to carry about a number of cards in consumption at different shops. 
     Although Bluetooth technology can be used in electronic devices for non-contact identification and in smart phones with no need of any special devices, its multi-site application only can be realized after being highly programmed and safety risk of cell phone may be increased with the Bluetooth on. Additionally, Bluetooth is power wasting. Therefore, an electronic device using Bluetooth as an identification terminal is unpractical. Furthermore, the Bluetooth technology is also high in cost to use due to its requirement to hardware such as interface, antenna. 
     SUMMARY 
     A technical problem to be solved by the present invention is to provide a wireless communication system and a method thereof which requires no hardware supports and have low cost, aiming at solving the defects in relevant arts 
     To solve the technical problem, the present invention adopts a technical solution as follows. A wireless communication system comprises: 
     a signal encoding module for encoding a preset high-frequency audio signal frequency according to a preset encoding rule, and creating an encoding library for storing the code; 
     a signal sampling module for sampling a high-frequency audio signal produced by a high-frequency audio signal generating device; 
     a signal transformation module for performing Fourier transformation on the sampled audio signal firstly to transform the audio signal into frequencies, acquiring a main frequency from the transformed frequencies, and storing the acquired main frequency; 
     a signal decoding module for decoding the main frequency into a preset code according to the code in the library; and 
     an output module for outputting the decoded code. 
     The present invention further provides a wireless communication method, comprising the steps of: 
     encoding a preset high-frequency audio signal frequency according to a preset encoding rule, and creating an encoding library for storing the code; 
     sampling a high-frequency audio signal produced by a high-frequency audio signal generating device; 
     performing Fourier transformation on the sampled audio signal to transform the audio signal into frequencies; 
     acquiring a main frequency from the transformed frequencies, and saving the acquired main frequency; 
     decoding the acquired main frequency into a preset code according to the code saved in the library; and 
     outputting the decoded code. 
     The present invention has the beneficial effects that site identification of the signal generating device can be realized by encoding a high-frequency audio signal frequency, producing a high-frequency audio signal by a signal generating device and identifying the high-frequency audio signal by a wireless communication system installed on a terminal so as to require no hardware supports and reduce cost. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present invention will be further described in details with reference to the attached drawings and embodiments, and in the drawings: 
         FIG. 1  is a block diagram of a wireless communication system according to a first embodiment of the present invention; 
         FIG. 2  is a schematic diagram of an application environment of the wireless communication system as shown in  FIG. 1 ; 
         FIG. 3  is a flow chart of a method for identifying a high-frequency audio signal produced by a signal generating device in  FIG. 2  according to the wireless communication system as shown in  FIG. 1 ; 
         FIG. 4  is a block diagram of a wireless communication system according to a second embodiment of the present invention; 
         FIG. 5  is a flow chart of a method for identifying a high-frequency audio signal produced by a signal generating device according to the wireless communication system as shown in  FIG. 4 ; 
         FIG. 6  is a flow chart of a signal processing method for an electronic device only receiving the audio signal produced by the signal generating device; and 
         FIG. 7  is a flow chart of a method for using both a first electronic terminal and a second electronic terminal as a signal transmitting terminal and a signal receiving terminal to perform two-way communication. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will be further described in details with reference to the attached drawings and embodiments. 
       FIG. 1  is a block diagram of a wireless communication system according to the first embodiment of the present invention. The wireless communication system  1  comprises a signal encoding module  10 , a signal sampling module  11 , a signal transformation module  12 , a filtration module  13 , a decoding module  14 , a numerical check module  15 , a numeric conversion module  16 , a multi-byte processing module  17  and an output module  18 . 
       FIG. 2  is a schematic diagram of an application environment of the wireless communication system  1  as shown in  FIG. 1 . During application, the wireless communication system  1  is installed in the electronic device  3 . The electronic device  3  comprises an audio sampling unit  31 , an internal memory unit  32 , an external memory unit  33  and a processing unit  34 . The internal memory unit  32  further comprises a register  321  and a buffer cache  332 . The processing unit  34  is used to execute the functions of each module of the wireless communication system  1 . 
     The signal encoding module  10  is used for creating an encoding library according to a certain rule. The rule refers to using a preset high-frequency audio signal frequency to represent a code that is a binary code and also a Morse code. When the code is a binary code, each preset high-frequency audio signal code represents a value of each bit of the binary system. For example, the value “0” of the 0 bit of binary system is expressed in a frequency of 17157 Hz; the value “1” is represented with a frequency of 19832 Hz; the value “0” of the first bit is expressed in a frequency of 17337 Hz; the value “1” of the first bit is represented with a frequency of 19910 Hz, and by this analogy, the values of each bit of the binary system are set with a preset high-frequency audio signal frequency. When the code is a Morse code, the “-”, “.” and the spacing in the Morse code are expressed in a preset high-frequency audio signal, respectively. The Morse code while data processing is converted into a numeric string represented with “0”, “1” and spacing, wherein “-” and “.” are converted into “1” and “0”, respectively. For example, “.” is expressed in 17.1 Hz, “-” in 18.1 Hz and the spacing in 19.1 Hz. 
     In the embodiment, an XOR parity bit can be inserted between bit binary digits when the code is a binary number or a Morse code, and further expressed in a preset high-frequency audio signal frequency. For example, the value “0” of the first parity bit is expressed in a frequency of 20120 Hz and the value “1” is represented with a frequency of 20150 Hz. 
     The signal generating device  2  which is provided with the code library at its terminal is able to produce a high-frequency signal according to the preset code or the code input by a user. If the preset binary code or the user-input binary code is 110, the signal generating device  2  sequentially produces a band of audio signal frequencies that stand for the numbers. 
     The signal generating device  2  outputs the high-frequency audio signal at a low power so that a common user is unable to listen to the high-frequency audio signal. In the embodiment, the frequency of the high-frequency audio signal produced by the signal generating device  2  ranges from 17.1 Hz to 21.5 Hz, wherein the signal generating device  2  may be any electronic devices capable of producing audio signals, such as the electronic devices in shopping malls, the smart phones or the computers with horns. In practical applications, the signal generating device  2  can be set to produce different audio signals by presetting unlike IDs according to its specific application fields so that other electronic devices  3  that are communicating with the signal generating device  2  can identify the device  2  via the audio signal produced by the device  2 . Generally, the signal generating device is able to produce 12 bits of signals, namely 4096 IDs distributable to different application terminals. 
     The signal produced by the signal generating device  2  usually covers from 5 mm to 10 cm; and the signal produced by a special signal generating device  2  may reach 10 m. The signal coverage of the signal generating device  2  mainly depends on the power of the amplifier installed herein, and may reach several meters in use of a DC-powered amplifier. 
     Preferably, the signal produced by the signal generating device is a clean sinusoidal signal so that the signal generated is relatively quiet. The square signal or the triangular wave signal may also be identified although noises may be produced. In the embodiment, a PWM signal source, a DDS signal source or a multi-frequency sinusoidal signal generator can be used to produce a clean sinusoidal signal. 
     When the signal produced by the signal generating device  2  is required to be identified by the system  1  through the electronic device  3 , the electronic device  3  starts the system  1  in response to the user&#39;s operation to read and identify the audio signal produced by the signal generating device  2 . For the specific method, please refer to  FIG. 3 . Firstly, in the step S 301 , the signal sampling module  11  samples an audio signal having a preset length produced by the signal generating device  2 . In the embodiment, the electronic device  3  acquires the high-frequency audio signal via the audio sampling unit  31 . In the embodiment, the audio sampling unit  31  is a microphone. 
     In the step S 302 , the filtration module  12  filters the sampled high-frequency audio signals to filter out high-frequency audio signals generated in ambient environment, such as knocking noise sounding from glass or metal. If “0” and “1” occur in a uniform frame signal, the signal is often deemed to be a high-frequency audio signal produced in ambient environment. 
     In the step S 303 , the signal transformation module  13  performs Fourier transformation on the sampled audio signal firstly to transform the audio signal into frequencies, and then acquires a main frequency from the transformed frequencies and stores the acquired main frequency into the internal memory. 
     In the step S 304 , the decoding module  14  acquires the frequency values from the memory one by one. 
     In the step S 305 , the decoding module  14  determines whether the acquired frequency value is one of the preset frequencies in the encoding table. If the acquired value is one of the preset frequencies in the encoding table, proceed to step  306 ; if the acquired value is not one of the preset frequencies in the encoding table, execute the step S 304  to acquire the next frequency value. 
     In step S 306 , the decoding module  14  acquires the number corresponding with the frequency value from the encoding table and stores the number into the register  321 . Taking the code in the encoding library as a binary number for example, if the frequency value is 17157 Hz, the number corresponding with the frequency value can be determined to be the number “0” corresponding with the 0 bit of the binary number; if the frequency value is 19910 Hz, the number corresponding with the frequency value can be determined to be the number “1” corresponding with the first bit of the binary number; if the frequency value is 20120 Hz, the number corresponding with the frequency value can be determined to be the number “1” of the first parity bit. 
     In step S 307 , the decoding module  14  determines whether the frequency values in the memory  31  are completely acquired. Return to the step S 303  to acquire next frequency value if the frequency values have not been completely acquired; if the frequency values have been completely acquired, proceed to step S 308 . 
     In step S 308 , the decoding module  13  determines whether the register  321  is full? If the register is not full, execute the step S 301  and resample an audio signal till the register  321  is fully written in numbers; if the register is not yet full, proceed to step S 309 . 
     In step S 309 , the numerical check module  15  checks whether the numerical value is correct. If the numerical value is incorrect, proceed to step S 310 ; if the numerical value is correct, proceed to step S 311 . In the embodiment, the numerical value may be deemed to be an invalid value under following two conditions: In the first case, the numbers “0” and “1” of the same bit occurs successively, for example, 17157 Hz and 19852 Hz or 19334 Hz and 19910 Hz. 
     In the second case, determine whether the check code is matched with the logic checksum of the numerical value before the parity code; if the check code matches with the logical checksum, the numerical value is correct; if the check code does not match with the logical checksum, the numerical value is incorrect. For example, if the frequencies of the audio signal are 17157 Hz, 17334 Hz and 20120 Hz, the number after the audio signal is decoded is 100, wherein the parity code is 1 and the XOR checksum of 00 is 0, and therefore the numerical value is incorrect. For another example, if the frequencies of the audio signal are 17157 Hz, 19910 Hz and 20150 Hz, the numerical value after the audio signal is decoded is 010, wherein the parity code is the “0” of the second bit and the logic checksum of the numerical value “10” is “1”, and therefore the numerical value is also incorrect. 
     In step S 310 , when the numerical value is incorrect, the numeric check module  15  resets the register  321  and the flow returns to the step S 301  to resample an audio signal for identification. 
     In step S 311 , when the numerical value is correct, the numeric conversion module  16  decodes the numbers in the register  321  into characters which represent the numbers, such as decimal numbers, letters, characters, and saves the decoded characters into the buffer cache  322 . 
     In step S 312 , the multi-byte processing module  17  determines whether the characters in the buffer cache  322  are multi-byte characters. If the characters are multi-byte characters, proceed to step S 313 , if the characters are not multi-byte characters, proceed to step S 314 . 
     In the embodiment, a multi-byte character identification code and a multi-byte character termination code can be set when the character is multi-byte. The character is determined to be a multi-byte character when a multi-byte character identification code in the buffer cache is identified by the multi-byte processing module  16 . 
     In step S 313 , the output module  18  outputs the numerical value and ends the identification process. 
     In step S 314 , the multi-byte processing module  16  determines whether the character is the termination code of the multi-byte character. If the character is not the termination code of the multi-byte character, proceed to step S 315 , if the character is the termination code thereof, proceed to step S 316 . 
     In step S 315 , the multi-byte processing module  14  resets the register  321  and then returns to the step S 301 . 
     In step S 316 , the output module  18  outputs the value of a character string which is formed by multiple bytes saved in the buffer cache  322 , and ends the identification process. 
       FIG. 4  and  FIG. 5  are respectively a flow chart of a wireless communication system  4  according to a second embodiment of the present invention and a flow chart of a method for identifying a high-frequency audio signal produced by a signal generating device  2  according to the wireless communication system  4 . The wireless communication system  4  comprises a signal encoding module  40 , a signal sampling module  41 , a filtration module  42 , a signal transformation module  43 , a decoding module  44  and an output module  45 , wherein the signal encoding module  40  presets a code for each high-frequency audio frequency. The code may be a single character, such as a number and a letter, or a combination of characters. For example, the 17.1 Hz high-frequency audio signal is set with a code 6, the 17.2 Hz audio signal with a code 7, the 17.3 Hz high-frequency audio signal with a code 8 and so on. The signal sampling module  41 , the filtration module  42  and the signal transformation module  43  have the same functions as that of the signal sampling module  11 , the filtration module  12  and the signal conversion module  13  in the first embodiment. That is the steps of S 601 , S 602  and S 603  are identical to the steps of S 301 , S 302  and S 303 . The functions of the decoding module  44  for executing the steps of S 604  and S 605  are same as that of the steps of S 304  and S 305  as shown in  FIG. 3 , and will not be repeatedly described any longer. 
     In step S 606 , the decoding module  44  acquires the code corresponding with the frequency value from the encoding table and stores the code into the buffer cache when the acquired frequency is one of the preset frequencies in the encoding table. 
     In step S 607 , the decoding module  44  determines whether the frequency values in the internal memory unit  32  are completely acquired. If the frequency values have not been completely acquired, return to the step S 604 ; if the frequency values have been completely acquired, proceed to step S 608 . 
     In step S 608 , the output module  43  determines whether the data transmission is completed. If the data were transmitted completely, return to step S 601 ; if the data were not transmitted completely, proceed to step S 609 . 
     In the embodiment, an initializer and a terminator can be preset. The initializer is a start identifier of the transmitted data and the terminator is a termination identifier of the transmitted data. A character read after the initializer is determined whether to be a terminator when confirming whether the data were transmitted completely, provided that the initializer had read first. If the character is the terminator, the data are confirmed to be transmitted completely; if the terminator is not read, the data has not read completely. 
     In step S 609 , the output module  45  outputs the code combination in the buffer cache. 
     In the embodiment, the output module  45  outputs the code between the initializer and the terminator. 
       FIG. 6  is a flow chart of a signal processing method for an electronic device  2  only receiving the audio signal produced by the signal generating device  2 . In step S 401 , receive the audio signal produced by the signal generating device  2 . 
     In step S 402 , process the audio signal as shown in  FIG. 3 . 
     In step S 403 , process the generated numerical values to perform the default function. 
       FIG. 7  is a flow chart of a method for using both a first electronic terminal  51  and a second electronic terminal  52  as a signal transmitting terminal and a signal receiving terminal to perform two-way communication. 
     In step S 501 , the first electronic terminal  51  generates an audio signal according to user input values. 
     In step S 502 , the second electronic terminal  52  receives the audio signal. 
     In step S 503 , the second electronic terminal  52  identifies the audio signal through the method as shown in the  FIG. 3 . 
     In step S 504 , the second electronic terminal  52  generates an audio response signal. 
     In step S 505 , the first electronic terminal  51  receives the audio response signal, and identifies the audio signal through the method as shown in the  FIG. 3 . The communication between the two terminals continues till the communication protocol preset by the user terminates. 
     The foregoing descriptions are merely preferred embodiments of the present invention, but are not intended to limit the protection scope of the present invention, and any technical solutions under the concept of the present invention shall all fall within the protection scope of the present invention. It should be pointed out that a plurality of improvements and modifications figured out by a person having an ordinary skill without departing from the principle of the present invention shall also fall within the protection scope of the present invention.